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Publication numberCN1290208 C
Publication typeGrant
Application numberCN 200410078979
Publication date13 Dec 2006
Filing date7 Mar 2001
Priority date7 Mar 2000
Also published asCA2373904A1, CA2373904C, CN1197192C, CN1372706A, CN1591931A, DE60143873D1, EP1191622A1, EP1191622A4, EP1191622B1, US6818352, US20030003363, US20050079406, WO2001067536A1
Publication number200410078979.0, CN 1290208 C, CN 1290208C, CN 200410078979, CN-C-1290208, CN1290208 C, CN1290208C, CN200410078979, CN200410078979.0
Inventors大道高弘, 五十岚聪, 西川聪, 本元博行, 峰松宏昌
Applicant帝人株式会社
Export CitationBiBTeX, EndNote, RefMan
External Links: SIPO, Espacenet
Lithium ion secondary cell, separator, cell pack, and charging method
CN 1290208 C
Abstract  translated from Chinese
一种包括正极、负极、隔膜和无水电解质的锂离子二次电池,其中所述隔膜主要由多孔片材制成,所述正极活性材料和负极活性材料可以被锂可逆地涂布和去涂布,在正极的锂的总量Qp(mAh)和可涂布负极的锂的量Qn(mAh)的关系为Qp>Qn,当以0.2Qn<Ic<2Qn的充电电流Ic(mA),以1<Qc/Qn<Qp/Qn的电荷Qc(mAh)开始对电池充电时,通过在负极上生成的锂物质对正极进行锂涂布,并且持续至Qc>Qp。 Comprising a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte lithium ion secondary battery, wherein the separator main positive electrode active material and negative electrode active material composed of a porous sheet material, the lithium can be reversibly applied to the coating and cloth, in the total amount of the positive electrode of lithium Qp (mAh) and the amount of lithium of the negative electrode may be coated Qn (mAh) relationship for Qp> Qn, when to 0.2Qn <Ic <2Qn charging current Ic (mA), to 1 <Qc / Qn <time Qp / Qn charge Qc (mAh) start charging the battery, the negative electrode by lithium species generated in the positive electrode of lithium coating, and continuing to Qc> Qp.
Claims(11)  translated from Chinese
1.一种锂离子二次电池隔膜,所述隔膜包括平均膜厚为10-35微米、基重为6-20克/米2,根据JIS P8117测定的透气性不大于100秒的片材A,25℃下的浸渍过电解质溶液的所述片材A的阻抗与单独电解质溶液的阻抗比为10或更小,该阻抗比×平均膜厚值不大于200微米。 1. A lithium ion secondary battery separator, the separator comprises an average thickness of 10-35 microns, a basis weight of 6-20 g / m 2, as measured according to JIS P8117 permeability of not more than 100 seconds sheet A , the impedance of the electrolytic solution impregnated sheet A at 25 ℃ electrolyte solution alone impedance ratio of 10 or less, the impedance ratio × average thickness of not greater than 200 microns.
2.权利要求1的隔膜,其中所述片材A由纤维组成,组成所述片材的纤维的平均纤维直径为所述片材A的平均膜厚的1/2-1/10。 2. The separator of claim 1, wherein the sheet A composed of fibers, the composition of the sheet for the average fiber diameter of the fibers of the average film thickness of sheet A is 1 / 2-1 / 10.
3.权利要求2的隔膜,其中所述片材A为非织造织物。 Separator of claim 2, wherein the sheet A non-woven fabric.
4.权利要求1-3中任一项的隔膜,其中所述片材A由聚酯、芳族聚酰胺、聚苯硫醚或聚烯烃或其两种或多种的组合物组成。 Separator according to any one of claims 1-3, wherein the sheet A made of polyester, aramid, polyphenylene sulfide or polyolefin or a combination of two or more of the composition.
5.一种包括多孔膜的锂离子二次电池隔膜,所述多孔膜的平均膜厚为10-35微米、基重为10-25克/米2,所述多孔膜包含包围片材A并且被电解质溶液溶胀和保持所述溶液的多孔有机聚合物膜B,所述片材A的平均膜厚为10-35微米、基重为6-20克/米2,根据JIS P8117测定的透气性不大于100秒,25℃下的浸渍过电解质溶液的所述片材A的阻抗与单独电解质溶液的阻抗比为10或更小,该阻抗比×平均膜厚值不大于200微米。 A porous film comprising a lithium ion secondary battery separator, the average thickness of the porous membrane 10 to 35 microns, a basis weight of 10-25 g / m 2, the porous membrane comprises and surrounds the sheet A Swelling and holding the electrolyte solution is the solution of the porous organic polymer film B, the average thickness of the sheet A is 10 to 35 microns, a basis weight of 6-20 g / m 2, as measured according to JIS P8117 permeability not more than 100 seconds, was immersed at 25 ℃ impedance over the electrolyte solution and the sheet A separate electrolyte solution impedance ratio of 10 or less, the impedance ratio × average thickness value of not more than 200 microns.
6.权利要求5的隔膜,其中所述片材A由纤维组成,组成所述片材的纤维的平均纤维直径为所述片材A的平均膜厚的1/2-1/10。 6. The separator of claim 5, wherein the sheet A composed of fibers, the composition of the average fiber diameter of the sheet of fibers is an average thickness of the sheet A of 1 / 2-1 / 10.
7.权利要求5的隔膜,其中所述片材A为非织造织物。 7. The separator of claim 5, wherein the sheet A non-woven fabric.
8.权利要求5的隔膜,其中所述多孔有机聚合物膜B主要由聚偏1,1-二氟乙烯组成。 8. The separator of claim 5, wherein the porous organic polymer film B is mainly composed of polyvinylidene fluoride composition.
9.权利要求8的隔膜,其中所述多孔有机聚合物膜B由含有92-98%摩尔的偏1,1-二氟乙烯的聚偏1,1-二氟乙烯共聚物组成。 Separator of claim 8, wherein the porous organic polymer film B containing 92-98% by mole of vinylidene vinylidene fluoride of polyvinylidene fluoride copolymer composition.
10.权利要求9的隔膜,其中所述多孔有机聚合物膜B由偏1,1-二氟乙烯、六氟丙烯和氯三氟乙烯的三元共聚物组成。 10. The separator of claim 9, wherein the porous organic polymer film B consisting of vinylidene fluoride, hexafluoropropylene and chlorotrifluoroethylene terpolymer composition.
11.权利要求10的隔膜,其中所述三元共聚物的共聚物组成为偏1,1-二氟乙烯,六氟丙烯和氯三氟乙烯,其中六氟丙烯为2-8%重量,氯三氟乙烯为1-6%重量。 11. The separator of claim 10, wherein the copolymer composition of the terpolymer is vinylidene fluoride, hexafluoropropylene and chlorotrifluoroethylene, wherein the hexafluoropropylene is 2-8% by weight of chlorine trifluoroethylene of 1-6% by weight.
Description  translated from Chinese
锂离子二次电池、隔膜、电池组和充电方法 Lithium ion secondary battery, a separator, a battery pack and a charging method

本申请是申请日为2001年3月7日的发明创造名称为“锂离子二次电池、隔膜、电池组和充电方法”的中国专利申请(国家申请号为No.01801175.6,国际申请号为PCT/JP01/01785)的分案申请。 This application is the filing date for the invention March 7, 2001 to create the name of Chinese patent application for "lithium ion secondary battery separator, battery packs and charging method" (National Application No. No.01801175.6, International Application No. PCT / JP01 / 01785) of the divisional application.

技术领域 FIELD

本发明涉及在过度充电时具有高安全性的低成本锂离子二次电池,涉及所述锂离子二次电池所采用的隔膜、电池组和装配有所述锂离子二次电池的电气/电子设备以及用于所述锂离子二次电池的充电方法。 The present invention relates to an electrical high security, low-cost lithium-ion secondary battery at the time of overcharge, relates to the use of a lithium ion secondary battery separator, and is equipped with a battery pack of the lithium ion secondary battery / electronics and a charging method for the lithium ion secondary battery.

背景技术 BACKGROUND

随着近年来便携式电子设备的普及和性能的增强,对具有高能密度的二次电池提出了相应要求。 With the popularity and performance of portable electronic devices in recent years, enhancement of the secondary battery has a high energy density made the corresponding requirements. 这种要求已通过更多地使用锂离子二次电池来获得满足,其中所述二次电池采用了可以进行电化学涂布(doped)和去涂布(dedoped)的碳材料,将锂用作负电极活性材料,而含锂的过渡金属氧化物作为正极活性材料。 This requirement has been increased by the use of a lithium ion secondary battery to be met, wherein said secondary battery can be carried out using an electrochemical coating (doped) and de-coating (dedoped) of carbon material, lithium is used as negative electrode active material, and a lithium-containing transition metal oxide as a positive electrode active material.

这种锂离子类型的二次电池通过锂离子在正极和负极之间的迁移进行充电和放电,由此完成电能的贮存和释放。 This type of lithium ion secondary battery by a lithium ion migration between the positive electrode and the negative electrode is charged and discharged, thereby completing the electrical energy storage and release. 锂离子二次电池具有高的能量密度,这是因为它输出的平均电压约等于3.7伏,约为常规二次电池的3倍,但是,由于电解质水溶液不能用于常规的二次电池,所以采用具有足够耐氧化-还原作用的无水电解质溶液。 A lithium ion secondary battery having a high energy density, because its average voltage output equal to about 3.7 volts, about 3 times the conventional secondary battery, however, since the electrolyte solution can not be used in conventional secondary battery, so the use of have sufficient resistance to oxidation - reduction of aqueous electrolyte solution. 由于这个原因,锂离子二次电池通常称为无水二次电池。 For this reason, a lithium ion secondary battery is generally called nonaqueous secondary battery.

由于无水二次电池使用易燃的无水电解质溶液作为电解质溶液,因此存在燃烧的危险,因此,在使用它们时必须保持高度警惕。 Because anhydrous secondary battery using flammable aqueous electrolyte solution as the electrolyte solution, so there is the risk of burning, so when using them must remain vigilant. 虽然许多情况可能导致产生燃烧的危险,但过度充电尤其危险。 Although many cases may lead to the risk of burning, but overcharging especially dangerous.

为了防止过度充电,采用恒定的电流和恒定的电压对现存的无水二次电池进行充电,并向电池提供精密的保护电路(安全电路:IC+FET×2)。 In order to prevent overcharging, and a constant current and constant voltage to the existing nonaqueous secondary battery is charged, and to provide sophisticated battery protection circuit (safety circuit: IC + FET × 2). 这些保护电路价格昂贵,因此增加了无水二次电池的成本。 These protective circuits are expensive, thus increasing the cost of nonaqueous secondary battery.

当通过保护电路来防止过度充电时,保护电路有时也会操作失败,因此基本上也不能认为它是安全的。 When through protection circuitry to prevent over-charging protection circuit sometimes fails, so basically can not believe it is safe. 对现有的无水二次电池作出了各种改进如提供安全排口(safety vent)、PTC元件和使用具有热熔化功能(切断功能)的隔膜从而在过度充电时如果发生保护电路失效的情况下能安全破坏处于过度充电的电池。 Anhydrous existing secondary batteries made various improvements such as providing safe discharge port (safety vent), PTC element and using a hot melt function (cut-off function) of the membrane and thus the protection circuit failure occurs when the overcharge if Under the safe destruction in overcharging of the battery. 但是,即使提供这种装置,根据过度充电的情况,过度充电时的安全性不是总能得到可靠保证,事实上,无水的二次电池仍然发生了燃烧的事故。 However, even if this means providing, according to the situation of over-charging, over-charging when the security is not always reliable guarantee, in fact, anhydrous secondary battery still burning accident occurred.

由于从安全和成本的角度来看,防止无水二次电池的过度充电的安全措施仍然不够充分,因此还是存在待解决的问题,已经提出各种方法以改善这个问题。 Because of safety and cost point of view, the nonaqueous secondary battery to prevent overcharge safety measures are still insufficient, and therefore there is still to be solved, various methods have been proposed to improve this problem.

改进的一种方法是针对当保护电路失效时以安全方式破坏所述电池。 An improved method for the protection circuit failure when the destruction of the battery in a safe manner. 这种方法的一个例子包括如日本专利号2928779、日本专利号3061759、日本专利号3113652、未审查的日本专利公开号2000-306610和其它出处提出添加一种在过度充电时能稳定产生气体的化合物,并引起安全排口快速启动,如日本专利号3061756提出加入一种在过度充电时进行聚合的化合物,由此阻断电流,以及如未审查的日本专利公开号11-45740中提出加入一种在过度充电时具有吸热作用的化合物;这此方法涉及的一些添加剂已被采用并且改进了无水二次电池的安全性。 An example of such a method include, for example Japanese Patent No. 2928779, Japanese Patent No. 3061759, Japanese Patent No. 3113652, Japanese Patent Unexamined Publication No. 2000-306610 and other references propose the addition of a compound capable of stable during overcharge gas generation and cause the safety discharge port quick start, as described in Japanese Patent No. 3061756 proposed adding a compound during the polymerization of overcharge, thereby blocking current, and Japanese Patent Publication No. 11-45740 if not examined proposed adding a compounds having an endothermic effect when overcharged; This method involves a number of additives which has been adopted and a nonaqueous secondary battery of improved safety.

另一种方法针对确保安全性,同时还通过除去保护电路或如具有热敏电阻系统的简单的保护来节省成本。 Another method for ensure security, but also by simply removing the protection circuit having a thermistor as the protection system or to save costs. 这种方法的例子包括如未审查的日本专利公开号6-338347、未审查的日本专利公开号2000-251932、未审查的日本专利公开号2000-277147、未审查的日本专利公开号2000-228215和其它出处提出的使用还原氧化往复(shuttle)型添加剂。 Examples of such methods include Failure Japanese Unexamined Patent Publication No. 6-338347, Japanese Patent Unexamined Publication No. 2000-251932, Japanese Patent Unexamined Publication No. 2000-277147, Japanese Patent Unexamined Publication No. 2000-228215 Source proposed use and other redox reciprocating (shuttle) additives. 在过度充电时氧化还原往复型添加剂引起正极和负极之间的氧化-还原反应,由此通过消耗过度充电的电流的机制来防止过度充电。 When overcharge redox shuttle additive causes oxidative between positive and negative - reduction reaction mechanism whereby by consuming excessive charging current to prevent overcharging. 现已采用一些这样的添加剂并且有助于改进无水二次电池的安全性,但它们没能除去保护电路或简化保护电路。 Has adopted a number of such additives and help to improve the safety of a nonaqueous secondary battery, but they are not able to simplify the removal of the protective circuit or a protection circuit.

未审查的日本专利公开号2000-67917提出了一种通过采用凝胶-聚合物的电解质膜来防止过度充电的技术,该专利还表明了消除或简化保护电路的可能性。 Japanese Patent Unexamined Publication No. 2000-67917 proposes a gel by using - a polymer electrolyte membrane to prevent over-charging technique, the patent also indicates the possibility of eliminating or simplifying the protection circuit. 但是,所述技术要求用于凝胶-聚合物电解质膜的膜厚不小于30微米,需要40微米或更大以获得足够的效果和甚至更大厚度以获得明显的效果。 However, the technical requirements for the gel - the film thickness of the polymer electrolyte membrane is not less than 30 microns, 40 microns or greater required to obtain a sufficient effect and even greater thickness to obtain significant results. 但是考虑到在大多数现有的无水二次电池中的隔膜厚度为25微米,没有广泛采用这种厚度,随着电池能量密度不断的提高,隔膜的厚度趋向于更薄。 However, taking into account the thickness of the diaphragm in most conventional nonaqueous secondary battery of 25 microns, such thickness not widely used, with the battery energy density continue to increase, the thickness of the diaphragm tends to be thinner.

未审查的日本专利公开号2000-123824也提出一种采用凝胶-聚合物的电解质来防止过度充电的技术,其中提出了消除或简化保护电路的可能性。 Japanese Patent Unexamined Publication No. 2000-123824 also proposes a gel - polymer electrolyte to prevent over-charging technique in which raised the possibility of eliminating or simplifying the protection circuit. 这种技术通过采用聚醚低聚物防止过度充电,但所述技术没有被广泛采用,因为与现有的无水二次电池相比,所述电池的放电特性极差。 By using this technique to prevent the excessive charging polyether oligomer, but the technology has not been widely adopted, as compared with conventional nonaqueous secondary battery, discharge characteristics of the battery is poor.

发明内容 SUMMARY

本发明的目的是通过提供一种无水电池来解决上述先有技术中的问题,所述无水二次电池在保持实用的电池特性的同时允许消除保护电路或简化保护电路成为热敏开关系统如热敏电阻和/或PTC元件,由此与常规的无水二次电池相比,提高了过度充电的安全性并降低了成本。 Object of the present invention is achieved by providing a non-aqueous battery to solve the above-described prior art problems, the nonaqueous secondary battery while maintaining a practical battery characteristic allows to eliminate or simplify protection circuit protection circuit becomes thermal switch system such as a thermistor and / or a PTC element, whereby as compared with a conventional nonaqueous secondary battery, improve overcharge safety and reduces costs.

为了解决这些问题,本发明提供了一种锂离子二次电池,该电池包括正极、负极、隔膜和无水电解质,其中:1)隔膜主要由多孔片材组成,2)正极活性材料和负极活性材料可以可逆地涂布和去涂布,使得Qp>Qn,其中Qp(mAh)是引起正极上含有的全部锂进行去涂布的必要电荷,Qn(mAh)是引起锂全部涂布至负极上的必需的电荷,并且3)当以范围为0.2Qn/h<Ic<2Qn/h的充电电流Ic(mA),范围为1<Qc/Qn<Qp/Qn的充电电荷Qc(mAh)对电池进行充电时,通过对电池充电而在负极上生成的锂颗粒开始锂在正极上的涂布,并且持续达到Qc>Qp。 To solve these problems, the present invention provides a lithium ion secondary battery which comprises a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte, wherein: 1) the membrane is mainly composed of a porous sheet, 2) a positive electrode active material and negative electrode active material may be reversibly coated and to the coating, such that Qp> Qn, where Qp (mAh) is necessary to cause all of the charge on the positive electrode containing the lithium to be coated, Qn (mAh) is applied to all causes lithium anode The required charge, and 3) When the range of 0.2Qn / h <Ic <2Qn / h of the charge current Ic (mA), in the range of 1 <Qc / Qn <Qp / Qn of electric charge Qc (mAh) of the battery When charging, the battery through the charging of lithium on the negative electrode particles begin to generate lithium coated on the positive electrode, and continued to achieve Qc> Qp.

本发明进一步提供一种锂离子二次电池组,所述电池组包括前述的锂离子二次电池和热敏开关系统如热敏电阻和/或PTC元件。 The present invention further provides a lithium ion secondary battery pack, the battery pack comprising the aforesaid lithium-ion secondary battery and the thermal switching system such as a thermistor and / or a PTC element.

本发明还进一步提供一种对前述锂离子二次电池进行充电的方法,该方法包括通过恒定的电流法对锂离子二次电池进行充电,并且基于下面的至少一个方面确定充电的完成:电池温度的升高、电池电压的下降或电池电压的振荡。 The present invention further provides a method of the aforementioned lithium ion secondary battery is charged, the method comprising by the constant current method, the lithium ion secondary battery is charged, and based on at least one aspect determines the charging is completed the following: battery temperature increases, the battery voltage drop or battery voltage oscillation.

本发明再进一步提供一种电气/电子设备,所述设备包括前述的锂离子二次电池或锂离子二次电池组。 The present invention still further provides an electrical / electronic apparatus, the apparatus comprising the aforementioned lithium ion secondary battery or a lithium ion secondary battery.

本发明又进一步提供一种锂离子二次电池隔膜,该隔膜包括具有平均膜厚为10-35微米、基重(basis weight)为6-20g/m2、透气性(JISP8117)不大于100秒、MacMullin数为10或更小并且MacMullin数×平均膜厚值不大于200微米的片材(A)。 The present invention further provides a lithium ion secondary battery separator, the separator comprising having an average film thickness of 10-35 microns, basis weight (basis weight) of 6-20g / m2, air permeability (JISP8117) is not more than 100 seconds, MacMullin number of 10 or less and the MacMullin number × average thickness is not greater than 200 microns sheet (A).

本发明再进一步提供一种锂离子二次电池隔膜,该隔膜包括平均膜厚为10-35微米、基重为10-25g/m2的多孔膜,所述多孔膜包括包围上述片材(A)并且被电解质溶液溶胀而又具有保持性的多孔有机聚合物膜(B)。 The present invention still further provides a lithium ion secondary battery separator, the separator comprising an average film thickness of 10-35 microns, a basis weight of the porous film 10-25g / m2, and the porous membrane surrounding said sheet comprising (A) and swollen by the electrolyte solution but a porous organic polymer film (B) retainability.

附图说明 Brief Description

图1图示了在实施例7和比较实施例1的过度充电时的电压变化。 Figure 1 illustrates a voltage change overcharge 7 and Comparative Example 1 when implemented in Example.

图2图示了实施例7的过度充电后的放电行为。 Figure 2 illustrates a discharge behavior overcharge Example 7 after.

图3为显示过度充电时在负极上生成的锂颗粒形状的电子显微相片。 Figure 3 is displayed when the negative electrode is overcharged in the electron micrographs generated lithium particle shape.

图4图示了实施例12的过度充电时的电压和电池表面温度的变化。 Voltage and battery surface temperature changes overcharge Example 12 Figure 4 illustrates the embodiment when.

具体实施方式 DETAILED DESCRIPTION

以下将更详细地对本发明进行描述。 Below in more detail of the present invention will be described.

本发明的锂离子二次电池为包括正极、负极、隔膜和无水电解质的电池,其中1)所述隔膜主要由多孔片材组成,2)可以可逆地涂布和去涂布正极活性材料和负极活性材料,使得Qp>Qn,其中Qp(mAh)是引起正极上含有的全部锂进行去涂布的必要电荷,Qn(mAh)是引起锂全部涂布至负极上的必需的电荷,并且3)当以范围为0.2Qn/h<Ic<2Qn/h的充电电流Ic(mA),范围为1<Qc/Qn<Qp/Qn的充电电荷Qc(mAh)对电池进行充电时,通过对电池进行充电使在负极上生成的锂颗粒开始锂在正极上的涂布,并且持续达到Qc>Qp。 A lithium ion secondary battery of the present invention to include a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte battery, wherein a) said membrane is mainly composed of a porous sheet, 2) to be reversibly coated and coating the positive electrode active material and The negative electrode active material, such that Qp> Qn, where Qp (mAh) is necessary to cause all of the charge on the positive electrode containing the lithium to be coated, Qn (mAh) is applied to all the necessary cause of lithium on the negative electrode of the charge, and 3 ) When the range is 0.2Qn / h <Ic <when 2Qn / h charge current Ic (mA), the range of 1 <Qc / Qn <Qp / Qn of electric charge Qc (mAh) to charge the battery, the battery by charging generated on the negative electrode so that lithium granules began lithium coated on the positive electrode, and consistently meet Qc> Qp.

并且所述二次电池展现出下述特性。 And the secondary battery exhibited the following characteristics.

[防止过度充电的功能]当以实用的充电电流Ic,使得0.2Qn/h<Ic<2Qn/h对本发明的锂离子二次电池进行充电时,在过度充电的情况下不会在负极上发生涂布,这样沉积的锂颗粒到达正极表面的附近,对正极进行涂布,这种现象持续至Qc>Qp,由此防止所述电池的任何进一步的过度充电。 [Prevent overcharging function] As a practical charging current Ic, so that 0.2Qn / h <Ic <2Qn / h for the lithium ion secondary battery of the present invention, charging the battery, does not occur in the case of over-charging on the negative electrode coating, such deposited particles reaching the vicinity of the lithium surface of the positive electrode, the positive electrode coating, this continues to Qc> Qp, thereby preventing any further excessive charging of the battery. 本发明人发现如果沉积到负极表面上的锂颗粒可以到达正极表面的附近至浅的过度充电深度,其中电荷Qc为使得1<Qc/Qn<Qp/Qn,那么不仅可以保证过度充电时锂离子二次电池的安全性,而且将到达正极表面附近的锂颗粒涂布至正极上,这样不会在正极和负极之间发生完全的内部短路,甚至在过度充电后可以放电。 The present inventors have found that if the lithium particles deposited on the negative electrode surface can reach the vicinity of the positive electrode surface to the excessive charging of shallow depth, wherein the charge Qc is such that 1 <Qc / Qn <Qp / Qn, then not only be able to guarantee that when the lithium ion overcharge safety of the secondary battery, and the lithium particles will reach the vicinity of the surface of the positive electrode coated on the positive electrode, so that a complete internal short circuit does not occur between the positive electrode and the negative electrode, even after over-charging can be discharged.

这种防止过度充电的功能的特征在于通过采用在过度充电时在负极上生成的锂颗粒对正极进行涂布来防止过度充电,并通过持续这种现象至Qc>Qp来保证过度充电时的电池的安全性;但是,为了保证电池的更高的安全性,优选这种现象持续至Qc/3Qn。 This prevents over-charging function is characterized by the use of over-charging when the anode to the cathode to generate lithium particles coated to prevent overcharging, and through continued this phenomenon to Qc> Qp to ensure that when the battery from overcharging security; however, in order to ensure greater safety of the battery, preferably this phenomenon continues until Qc / 3Qn.

在Qc/Qn<1时出现这种现象的锂离子二次电池是不能够进行完全充电的电池,因此不优选这种电池。 In Qc / Qn <1 this phenomenon occurs when the lithium ion secondary battery is not capable of fully charged battery, the battery is not preferable. 当没有出现Qc/Qn<Qp/Qn的这种现象时,由于涉及到锂量的原因,不会出现这种Qc/Qn>Qp/Qn的现象。 When no Qc / Qn <Qp / Qn of this phenomenon, because of the amount involved in lithium, will not happen Qc / Qn> Qp / Qn phenomenon.

不容置疑的是,为了获得具有这种防止过度充电的锂离子二次电池,必须使Qp和Qn的关系为Qp>Qn。 No doubt that in order to obtain to prevent excessive charging of having such a lithium ion secondary battery, so that the relationship must Qp and Qn is Qp> Qn. 本发明的防止过度充电的功能是通过采用在过度充电时锂颗粒沉积在负极表面上来获得的,但是这些锂颗粒最初包含在正极上,由于当时可用的电荷量为Qp-Qn,如果Qp<Qn,本发明的防止过度充电的功能原则上是不可能的。 To prevent excessive charging of the functions of the present invention is achieved by the use of lithium during overcharge particles are deposited onto the surface of the negative electrode obtained, but these particles initially contained lithium on the positive electrode, due to the amount of charge available at the time for the Qp-Qn, if Qp <Qn , the function of preventing overcharging of the principles of the present invention is not possible.

考虑到本发明的锂离子二次电池的更高安全性,当负极完全用锂(Qp-Qn)进行涂布时优选使用正极上剩余的一半量的锂,这样表现出防止过度充电的功能。 Taking into account the higher safety for lithium ion secondary battery of the present invention, when the negative electrode is completely coated with lithium (Qp-Qn) is preferably used on the remaining half amount of the positive electrode of lithium, thus showing the function of preventing overcharging. 也就是说,更优选采用较浅充电深度,此时Qc满足1<Qc/Qn<0.5(Qp/Qn+1)来表现出防止过度充电效果。 That is, the use of shallow charge depth is more preferably, this time Qc satisfies 1 <Qc / Qn <0.5 (Qp / Qn + 1) to exhibit the effect of preventing overcharging.

在此,可以由每单位面积上的正极活性材料和负极活性材料的重量来计算Qp和Qn。 Here, the positive electrode active material may be formed per unit area and the weight of negative electrode active material calculated Qp and Qn. 它们也可以通过形成三电极系统电池并测量充电/放电来确定,其中所述三电极系统通过使用正极或负极作为工作电极和锂金属作为参考电极以及对电极形成。 They can also form a three-electrode system and the measurement cell charge / discharge is determined, wherein the three-electrode system by using the positive or negative electrode is formed as a working electrode and lithium metal as a reference electrode, and.

可以采用下面的方法来确保本发明的电池中的这种防止过度充电的功能。 The following methods may be employed to ensure that the battery of the present invention to prevent overcharging of this function. 具体而言,将正极和负极从本发明的锂离子二次电池中除去,通过上面描述的方法测量Qp和Qn以确保关系Qp>Qn。 Specifically, the positive electrode and the negative electrode from the lithium ion secondary battery of the present invention, removing, Qp and Qn measured by the method described above to ensure that the relationship between Qp> Qn. 也可以从本发明的锂离子二次电池中除去正极、负极和隔膜,通过隔膜连接正极和负极,并注入电解质(电解质溶液)以制造评估电池1。 And to be removed from the lithium ion secondary battery of the present invention, a positive electrode, a negative electrode and a separator, connected to the positive electrode and the negative electrode through the membrane, and injecting an electrolyte (electrolyte solution) to produce an evaluation battery. 已经确认当评估电池1采用满足条件0.2Qn/h<Ic<2Qn/h的充电电流Ic进行充电时,当Qc的范围为1<Qc/Qn<Qp/Qn时,可以观察到电池电压下降、电池电压振荡或者电池电压升高的基本停止。 When the evaluation has confirmed that when using the battery 1 satisfies the condition 0.2Qn / h <Ic <2Qn / h of charging charging current Ic, Qc when the range of 1 <Qc / Qn <Qp / Qn, the battery voltage drops can be observed, the battery voltage or the battery voltage oscillation basically stopped rising. 将电池电压下降、电池电压振荡或电池电压升高的基本停止开始时的电荷定义为Q1(mAh)。 The battery voltage drops, the battery voltage or battery voltage oscillation elevated basically stopped at the beginning of the charge is defined as Q1 (mAh). 还确认电池电压的振荡或电池电压升高的基本停止,或者根据电池电压的下降,持续至高达Qc>Qp。 Also confirm that the battery voltage or battery voltage oscillation elevated basically stopped, or according to the battery voltage drop, and continued up to Qc> Qp. 然后从本发明的锂离子二次电池中除去隔膜和正极,通过隔膜使正极与负极收集极(collector)相连(即Qn=0),将电解质(电解质溶液)注入以制造评估电池2。 A separator and a positive electrode was then removed from the lithium ion secondary battery of the present invention, the positive electrode and the negative electrode through the separator collecting electrode (collector) connected (i.e., Qn = 0), the electrolyte (electrolyte solution) was injected to evaluate the battery manufactured 2. 对于采用满足0.2Qn/h<Ic<2Qn/h的充电电流Ic进行充电而言,这个评估电池2中的负极电极收集极作为负极,将电池电压降低,电池电压振荡或电池电压的升高基本停止开始时的电荷定义为Q2(mAh)。 For use meet 0.2Qn / h <Ic <2Qn / h in terms of the charging current Ic were charged, in the assessment battery negative electrode collector 2 as a negative electrode, the battery voltage decreases, the battery voltage or the battery voltage increases the oscillation basic Stop at the beginning of the charge is defined as Q2 (mAh). 在此,如果关系Q1>Q2(理想的是Q2=Q1-Qn)成立,可以观察到电池电压下降、电池电压振荡或者电池电压升高的基本停止将取决于负极上生成的锂颗粒,所述锂原本包含在正极上,并且可以确认所需的防止过度充电的功能。 Here, if the relationship Q1> Q2 (desirably Q2 = Q1-Qn) set up, it can be observed battery voltage drops, the battery voltage or the battery voltage increases the oscillation is stopped will depend substantially on the negative electrode for lithium particles produced, the lithium originally contained in the positive electrode, and it was confirmed that the desired function of preventing the excessive charging.

在上述的测试中,当难以除去负极收集极时,可以使用铜箔或锂箔代替电极收集极。 In the above test, when it is difficult to remove the negative electrode collector, lithium foil or copper foil may be used instead of the electrode collector. 通常用于锂离子二次电池的电解质溶液可以用作用于测试的电解质溶液。 Electrolyte solution is generally used for a lithium ion secondary battery may be used as an electrolyte solution for testing.

当本发明的锂离子二次电池具有防止过度充电的功能时,通过充电方式引入的电能以焦耳热的形式释放出系统外。 When the lithium ion secondary battery of the present invention has a function of preventing the excessive charging, the introduction of electric energy through the charging mode in the form of Joule heat released outside the system. 焦耳热可以(充电电流×电池电压)来表示。 Joule heating can (battery charging current × voltage) to represent. 因此,如果采用大的充电电流,焦耳热效应将占主导地位,并且难以精确评估防止过度充电的效果。 Therefore, if a large charging current, Joule heating effects will dominate, and it is difficult to accurately assess the effect of preventing overcharging. 对于范围为0.2Qn/h<Ic<2Qn/h的实际充电电流Ic应用而言,优选评估电池采用较小的容量。 For the range of 0.2Qn / h <Ic <2Qn / h of the actual charge current Ic applications, preferably a smaller battery capacity assessment. 优选上述的评估电池为钮扣型(币型coin-type)电池,但不限于此。 Preferably, the button-type battery evaluation (coin type coin-type) battery, but is not limited thereto.

以下将对采用钴酸锂作为正极和可以采用锂进行涂布/去涂布的碳材料涂为负极的最常见类型的锂离子二次电池的前述防止过度充电功能进行解释。 The following will use lithium cobalt oxide as a positive electrode and lithium can be coated / painted to the coated carbon material as the negative electrode of the most common types of lithium ion secondary battery to prevent overcharging of the preceding function will be explained. 通常设计这种类型的锂离子二次电池系统使得Qn大约为Qp的一半,即2Qn=Qp。 This type of design is typically a lithium ion secondary battery system such that about half Qp Qn, i.e. 2Qn = Qp. 对于用于蜂窝式电话的尺寸的这类常规锂离子二次电池而言,如果当在Ic(充电电流Ic=Qn/h)超过充电百分率的约200%(电荷Qc=Qp)下充电,这时充电率将耗尽正极上所有的锂,那么将发生爆炸和燃烧。 For such conventional lithium ion secondary batteries for cellular telephone size, if when Ic (charging current Ic = Qn / h) of more than about 200% the percentage of the charge (charge Qc = Qp) charging, which When charging rate will deplete all of lithium on the positive, it will explode and burn.

根据这一点,可以通过防止正极上锂的全部消耗,即通过停止进一步充电来确保过度充电时的安全性,但是本发明的锂离子二次电池的防止过度充电功能的特征在于通过在过度充电时在负极上沉积锂颗粒来实现这一点。 According to this, by preventing complete consumption of the positive electrode of lithium, i.e., by stopping the charge to further ensure the safety during overcharge, but a lithium ion secondary battery of the present invention prevents overcharging function is characterized by excessive charging lithium deposited on the negative electrode particles to achieve this. 也就是说,必须在充电百分率不大于200%(Qc<Qp)和更优选不大于150%(Qc<0.5(Qp+Qn))时开始锂颗粒在正极上的沉积。 Start particles deposited on the positive electrode of lithium That is, must not be more than 200% in the percentage of charge (Qc <Qp) and more preferably not more than 150% (Qc <0.5 (Qp + Qn)).

没有持续采用沉积在负极上的锂颗粒来涂布正极时,将不能防止过度充电。 No sustained by the deposition of lithium on the negative electrode particles to the coating of the positive electrode, will not prevent the excessive charging. 也就是说,必须以至少200%(Qc>Qp)和更优选至少300%(Qc>3Qn)的充电率持续充电。 In other words, must be at least 200% (Qc> Qp) and more preferably at least 300% (Qc> 3Qn) charging rate continues charging.

本发明的具有基于上述机理的防止过度充电功能的锂离子二次电池具有下面的特征。 With the present invention has the following features based on the above mechanism to prevent excessive charging of the lithium ion secondary battery.

1)当以满足0.2Qn/h<Ic<2Qn/h的充电电流Ic对电池进行充电时,发生电池电压下降、电池电压振荡或者电池电压的升高基本停止时的Qc的范围为1<Qc/Qn<Qp/Qn。 1) When satisfied 0.2Qn / h <Ic <2Qn / h of the charging current Ic to charge the battery, the battery voltage drop occurs, the battery voltage or the battery voltage increases the oscillation range of the basic time of stopping Qc is 1 <Qc / Qn <Qp / Qn.

在此,当负极上生成的锂颗粒在正极上涂布时,出现电池电压的下降。 Here, when the lithium particles produced on the negative electrode coated on the positive electrode, the decline in battery voltage. 电池电压的振荡表明锂颗粒的间歇涂布。 Indicates that the battery voltage oscillation intermittently coated lithium particles. 电池电压的下降和振荡取决于电池的内阻,当电池的内阻较小时,难以观察到这些现象。 Battery voltage drop and the oscillation depends on the internal resistance of the battery, when the internal resistance of the battery is small, difficult to observe these phenomena. 在这些情况下,有时可以通过明显减少电压取样时间来观察它们。 In these cases, sometimes can significantly reduce the voltage sampling time to observe them. 在锂颗粒在负极上沉积和涂布至正极的极快的循环的情况下也难以观察到电池电压的下降和电池电压的振荡。 In the lithium particles in the negative electrode deposition and coating the positive electrode to fast cycle situation also difficult to observe the battery voltage drop and battery voltage oscillation. 当翻转循环(turnover cycle)较快并且电池的内阻抗较低时,观察到电池电压的升高基本停止的明显现象。 When flipping loop (turnover cycle) is fast and low internal impedance of the battery, the battery voltage phenomena observed significant increase in the basic stop.

2)当以满足0.2Qn/h<Ic<2Qn/h的充电电流Ic对电池进行充电时,开始10mV或更大的电池电压振荡并持续至Qc>Qp,这时电荷Qc的范围为1<Qc/Qn<Qp/Qn。 2) When in order to meet 0.2Qn / h <Ic <2Qn / h of the charging current Ic to charge the battery, start 10mV or more oscillating and continue until the battery voltage Qc> Qp, then the range of charge Qc is 1 < Qc / Qn <Qp / Qn.

因此,电池电压振荡证明了锂颗粒在负极上的沉积和在正极上的涂布的循环的重复,如果持续至Qc<Qp,则表现出足够的防止过度充电功能。 Therefore, the battery voltage oscillation proved repeated deposition of lithium on the negative electrode particles and coated on the positive electrode of the cycle, if continued to Qc <Qp, exhibit sufficient to prevent the excessive charging.

3)当以满足0.2Qn/h<Ic<2Qn/h的充电电流Ic对电池进行充电至Qc为2<Qc/Qn<3并且随后以满足0.1Qn/h<Id<0.5Qn/h的放电电流Id进行放电时,放电电量Qd的范围为1<Qd/Qn<Qp/Qn。 3) When the meet 0.2Qn / h <Ic <2Qn / h of the charging current Ic to charge the battery to Qc as 2 <Qc / Qn <3 and then to meet 0.1Qn / h <Id <0.5Qn / h discharge When the discharge current Id, Qd discharge capacity range of 1 <Qd / Qn <Qp / Qn.

因为没有出现完全的内部短路,此后可以对本发明的锂离子二次电池进行放电。 Because there is no internal short-circuit occurred completely, thereafter be lithium ion secondary battery of the present invention will be discharged. 如果防止过度充电的机理起作用,那么考虑到负极上剩余的锂,放电容量Qd的范围为1<Qd/Qn<Qp/Qn。 If the mechanism acts to prevent overcharge, then consider the remaining lithium negative electrode, the discharge capacity Qd is in the range of 1 <Qd / Qn <Qp / Qn.

4)当采用满足0.2Qn/h<Ic<2Qn/h的充电电流Ic进行充电时,电池电压总的不大于5.5V,其中电荷Qc满足1<Qc/Qn<1.5Qp/Qn。 4) When satisfied 0.2Qn / h <Ic <2Qn / h of charging charging current Ic, the battery voltage is not greater than the total of 5.5V, wherein the charge Qc satisfies 1 <Qc / Qn <1.5Qp / Qn.

由于通过上述机理防止了本发明的锂离子二次电池的进一步充电,电池电压不会升至电解质(电解质溶液)分解的电压。 Due to the above mechanism preventing further charging the lithium ion secondary battery of the present invention, the battery voltage does not rise electrolyte (electrolyte solution) decomposition voltage. 这意味着只要使用当前常用的一些正极材料,当防止过度充电功能起作用时,电压不会超过5.5V。 This means that as long as the current number of cathode materials commonly used to prevent excessive charging when active, the voltage does not exceed 5.5V.

5)当Qc满足Qc/Qn=0.5时在1kHz下的电池内阻抗R0.5与当Qc满足Qc=Qp时在1kHz下的电池内阻抗R2的关系是1.5R0.5>R2。 5) When the Qc meet Qc / Qn = 0.5 R0.5 impedance at 1kHz under the battery when Qc Qc = Qp satisfied within the cell impedance at 1kHz relationship with R2 is 1.5R0.5> R2.

当防止过度充电功能起作用时,通常不会发生伴随过度充电的分解,因此电池内阻抗没有明显的增加。 When the function is activated to prevent excessive charging, usually accompanied by the decomposition of overcharging does not occur within the cell impedance and therefore no significant increase.

6)对于满足Qp<Qc<1.5Qp范围的Qc而言,通过对电池充电在负极上生成的锂颗粒的最大长度为100微米或较小。 6) For satisfy Qp <Qc <1.5Qp range Qc, the maximum length of the battery by charging generated on the negative electrode for lithium particles is 100 microns or less.

由于沉积在负极上的锂颗粒变得很细使得它们快速到达正极表面的附近,所以显示出防止过度充电的功能。 Since the lithium deposited on the negative electrode becomes very fine particles such that they rapidly reach the vicinity of the positive electrode surface, so showing the function of preventing overcharging.

原则上本发明的锂离子二次电池具有上面1)-6)的所有的特点,但是当充电电流随着电池容量的增加而增大时,由于焦耳热的问题,将存在不具有全部特性的一些情况。 A lithium ion secondary battery of the present invention having the above principle 1) -6) in all characteristics, but when the charging current increases as the battery capacity is increased, the problem due to the Joule heat, there will not have all the features of some cases. 总体而言,可以通过满足上面特性1)-6)中的一个或更多个,优选两个来确保本发明的锂离子二次电池所需的防止过度充电的功能。 Overall, may be required to ensure that a lithium ion secondary battery of the present invention is obtained by satisfying the above properties 1) -6) in one or more, preferably two functions preventing overcharging.

如防止过度充电的功能所期望的那样,本发明的锂离子二次电池在过度充电时没有产生电解质溶液的反常分解,也没有引起正极的晶体结构的破坏。 As the function of preventing overcharging, as expected, a lithium ion secondary battery of the present invention is not produced at the time of overcharging abnormal decomposition of the electrolyte solution, did not cause destruction of the crystal structure of the positive electrode. 可以通过如GC-MS的方法来确定不存在所述电解质溶液的反常分解。 By methods such as GC-MS to determine the absence of abnormal decomposition of the electrolyte solution. 可以通过X-射线衍射的峰形来确定不存在正极的晶体结构的破坏。 By X- ray diffraction to determine the peak shape of the absence of destruction of the crystal structure of the positive electrode.

[电极]对于本发明的锂离子二次电池的正极和负极而言,使用可以使锂可逆涂布和去涂布的活性材料并且可用通常用于锂离子二次电池的材料而不受任何特别的限制,只要Qp和Qn满足关系Qp>Qn。 [Electrode] For the present invention, a lithium ion secondary battery positive electrode and the negative electrode, the use of reversible coating and allows lithium to the active material and is coated by conventional lithium ion secondary battery without any particular material for the limitation as long as Qp and Qn satisfy the relationship Qp> Qn.

所述正极和负极通常各自由活性材料、粘合活性材料并且保持电解质溶液的粘合剂聚合物和收集极组成。 The positive electrode and the negative electrode active material are each generally, the active material and the adhesive holding the binder polymer electrolyte solution and collection electrode composition. 也可以加入导电助剂以提高所述电极的导电性。 A conductive additive can also be added to increase the conductivity of the electrode.

优选将含锂的过渡金属氧化物如LiCoO2、LiMn2O4或LiNiO2用作本发明锂离子二次电池的正极活性材料。 Preferably the lithium-containing transition metal oxides such as LiCoO2, LiMn2O4 or LiNiO2 is used as a lithium ion secondary battery of the present invention, the positive electrode active material. 对于负极活性材料而言,优选使用烧结的有机聚合物化合物如聚丙烯腈、酚醛树脂、可溶可熔酚醛树脂或纤维素、烧结的焦炭或沥青、或碳材料如人造石墨或天然石墨。 For the negative electrode active material, it is preferred to use sintered organic polymer compounds such as polyacrylonitrile, phenol resin, novolak resin or cellulose, sintered coke or pitch, or a carbon material such as artificial graphite or natural graphite.

作为粘合剂聚合物,可以使用氟树脂如聚偏1,1-二氟乙烯(PVdF)、含有PVdF和六氟丙烯(HFP)或全氟甲基乙烯基醚(PFMV)以及四氟乙烯的共聚物的PVdF共聚物树脂和聚四氟乙烯、氟橡胶等;烃基聚合物如苯乙烯-丁二烯共聚物和苯乙烯-丙烯腈共聚物;和羧甲基纤维素、聚酰亚胺树脂等,但是不限于此。 As the binder polymer, may be used fluororesin such as polyvinylidene fluoride (PVdF), containing PVdF and hexafluoropropylene (HFP) or perfluoro methyl vinyl ether (PFMV) and tetrafluoroethylene PVdF copolymer resin and polytetrafluoroethylene, fluorine rubber copolymers and the like; hydrocarbon polymers such as styrene - butadiene copolymers and styrene - acrylonitrile copolymers; and carboxymethyl cellulose, polyimide resin etc., but is not limited thereto. 也可以单独或两者或更多种的组合的形式使用它们。 Can also be used alone or in the form of a combination of two or more kinds of them.

对于收集极而言,将具有优异的抗氧化性的材料用于正极,具有优异的抗还原性的材料用于负极。 For the collector, the will have excellent oxidation resistance of the material used in the cathode, has excellent resistance to reduction of material for the negative electrode. 具体而言,铝、不锈钢等可以用于正极收集极,铜、镍、不锈钢等可以用于负极收集极。 Specifically, aluminum, stainless steel, etc. can be used for the positive electrode collector, copper, nickel, stainless steel, etc. can be used for the negative electrode collector. 形状可以为箔状或网状。 Shape may be a foil or mesh. 具体而言,优选铝箔用于正极收集极,优选铜箔用于负极收集极。 Specifically, preferably used for the cathode collector foil, preferably copper foil for the negative electrode collector.

优选炭黑(乙炔黑)用作导电助剂,但不限于此。 Preferably carbon black (acetylene black) was used as a conductive additive, but is not limited thereto.

就活性材料、粘合剂聚合物和导电助剂的混合比率而言,优选3-30重量份的粘合剂聚合物和优选0-10重量份的导电助剂,其中重量份基于100重量份的活性材料计。 On the mixing ratio of the active material, a conductive additive and a binder polymer in terms of, preferably 3-30 parts by weight of the binder polymer and preferably 0-10 parts by weight of a conductive additive, wherein the parts by weight based on 100 parts by weight Total active material.

对于制备电极的方法没有特别的限制,可以采用任何公众已知的方法。 There is no particular limitation on the method of preparing an electrode, any public known methods.

[隔膜]本发明的锂离子二次电池优选采用以下两种形式的隔膜。 [Separator] a lithium ion secondary battery of the invention preferably employs the following two forms of the diaphragm.

第一种形式为片材(A),平均膜厚为10-35微米,基重为6-20g/m2,透气性(JIS P8117:100毫升的空气以2.3cmHg的压力通过1平方英寸区域所需的时间)不超过100秒,MacMullin数为10或更小并且MacMullin数×平均膜厚值不大于200微米。 The first form of a sheet (A), an average thickness of 10-35 microns, a basis weight of 6-20g / m2, air permeability (JIS P8117: 100 ml of air to pressure 2.3cmHg through one square inch area of the The time required) is not more than 100 seconds, MacMullin number of 10 or less and MacMullin number × average thickness value of not more than 200 microns. 这种类型的片材具有较大的缝隙,正如组装的电池具有许多通孔,沿着隔膜通孔测量的正极和负极之间的最小长度与隔膜膜厚的大致比率(曲率)为1,在过度充电时在负极上生成的锂颗粒可以更容易地到达正极表面的附近。 This type of sheet material having a large gap, as the assembled battery having a plurality of through holes, generally the ratio (curvature) of the minimum length of the diaphragm along the thickness of the positive electrode and the negative electrode a separator between the measured through-hole 1, in on the negative electrode during excessive charging of the lithium particles can be generated more easily reach the vicinity of the positive electrode surface. 因而这是优选的以表现出上述的防止过度充电的功能。 Therefore, this is preferable to exhibit the above function to prevent overcharging.

平均膜厚小于10微米并且基重小于6g/m2的片材更易表现出防止过度充电的功能,但是它的强度不够并且容易短路,因此不优选用作隔膜。 The average film thickness of less than 10 microns and a basis weight of less than 6g / m2 of the sheet easier to exhibit the function of preventing overcharging, but its strength is insufficient and a short circuit easily, and therefore is not preferably used as a separator.

从避免短路来看归一化的击穿强度可以作为一个指标。 From the point of view to avoid the normalized short-circuit breakdown strength can be used as an indicator. 优选归一化的击穿强度为至少3克/微米,优选有效击穿强度(归一化的击穿强度×膜厚)为至少80克。 Preferably normalized breakdown strength of at least 3 g / micron, preferably effective breakdown strength (normalized breakdown strength × film thickness) of at least 80 grams. 归一化的击穿强度值的测量如下:将片材置于直径为11.3mm的固定框内,用0.5mm尖端半径的针垂直刺入所述片材的中部,以50mm/min的固定速度将针拖出,并基于所述片材的平均膜厚,对在所述片材上打开通孔时作用于针上的力进行归一化。 The normalized values of breakdown strength measured as follows: The sheet was placed in a fixed frame having a diameter of 11.3mm, 0.5mm needle tip radius of the vertical piercing the middle of the sheet, to 50mm / min at a fixed speed out of the needle, and based on the average thickness of the sheet, a through hole is opened on the sheet of normalizing effect on the force on the needle.

采用平均膜厚小于10微米,基底重小于6克/米2的片材难于得到满足所述击穿强度的条件的片材。 Using the average film thickness of less than 10 microns, less than the basis weight of the sheet 6 g / m 2 is difficult to obtain the sheet strength to meet the breakdown condition.

对于平均膜厚大于35微米,基重大于20克/米2并且透气性(JISP8117)超过100秒的片材不仅从防止过度充电的功能来看是不利的,而且从减少的电池特性和伴随内阻抗增加的能量密度的减少的观点来看也是不优选的。 For the average film thickness greater than 35 microns, based significant at 20 g / m 2 and permeability (JISP8117) over 100 seconds of the sheet, not only from the functional point of view to prevent the excessive charging is disadvantageous, but also from the reduction of battery characteristics and the accompanying increasing impedance reduction perspective view of energy density is not preferable. 当考虑电池的特性时,优选片材(A)具有10或更小的MacMullin数和不大于200微米的MacMullin数×平均膜厚值。 When considering the characteristics of the battery, preferably a sheet (A) having 10 or less and the number of MacMullin number MacMullin no greater than 200 micrometers × average thickness value. 更优选MacMullin数×平均膜厚值不大于150微米。 More preferably MacMullin number × average thickness not greater than 150 microns. 在此,MacMullin数为电池隔膜的离子导电性的一个指标,它是浸渍过电解质溶液的片材(A)的阻抗与单独电解质溶液的阻抗比。 Here, MacMullin number is an indicator of the ion conductivity of the battery separator, it is impregnated with the electrolytic solution of the sheet (A) with the impedance of the electrolyte solution alone impedance ratio. 通过本发明,MacMullin数是指在25℃下测量的值。 By the present invention, MacMullin number refers to a value measured at 25 ℃ in. 当所述片材具有大于35微米的平均膜厚、大于20克/米2的基重以及超过100秒的透气性(JIS P8117)时,难以满足MacMullin数和MacMullin数×平均膜厚值的条件。 When the sheet has an average thickness greater than 35 microns, greater than 20 g / m 2 base weight and more than 100 seconds permeability (JIS P8117), it is difficult to meet the MacMullin number and the MacMullin number × average thickness value of the condition .

对于所述片材(A)的具体例子而言,可以提及的片材具有膜上的硬的突起或激光开的孔,其结构如常规用于锂离子二次电池的隔膜的聚烯烃细孔膜,或者由各种纤维如非织造织物形成的片材;但是,对片材(A)没有特别的限制,只要满足上面给出的条件即可。 For the sheet (A) Specific examples of, the sheet may have a hard-mentioned projection or laser apart apertures film, fine structure such as a conventional lithium ion secondary battery separator of polyolefin porous membrane, or a sheet from a variety of fibers such as a nonwoven fabric formed; however, there is no particular limitation on the sheet (A), as long as satisfying the above conditions may be given.

当片材(A)由纤维组成时,组成片材的纤维的平均纤维直径优选为片材(A)的平均膜厚的1/2至1/10。 When the sheet (A) composed of fibers, the composition of the sheet of fibers of average fiber diameter is preferably a sheet (A) of the average film thickness of 1/2 to 1/10. 如果平均纤维直径小于片材(A)的平均膜厚的1/10时,曲率将增加,不仅不能获得足够的电池特性,而且对防止过度充电功能也产生不利的影响。 If the average fiber diameter is less than the average thickness of the sheet (A) is 1/10, the curvature will increase, not only fail to obtain sufficient battery characteristics, but also to prevent excessive charging adversely affected. 如果平均纤维直径大于片材(A)的平均膜厚的1/2时,在纤维之间存在较小的交织,不能获得足够强度的片材。 If the average fiber diameter is greater than the average thickness of the sheet (A) is 1/2, there is a smaller interleaving between the fibers, the sheet can not be obtained a sufficient strength. 片材(A)的网孔也太大,当制备所述电池时产生短路问题。 Sheet (A) of the mesh is too big, short circuit problems when preparing the battery. 当这种片材(A)用于下面描述的本发明的隔膜的第二种形式时,形成许多针孔并且不能获得令人满意的隔膜。 When this second form of the separator sheet (A) used in the following description of the present invention, forming a plurality of pinholes and can not obtain a satisfactory membrane.

当片材(A)由纤维组成时,优选为非织造织物的形式。 When the sheet (A) composed of fibers, preferably in the form of a non-woven fabric. 制备非织造织物的方法可以为任何常用的干片法、纺粘法、水针(water needle)法、射流喷网法、湿片法以及熔体喷射法。 The method of preparation of non-woven fabric can be any conventional dry film method, spunbond, water injection (water needle) method, spunlace, wet-plate method and melt spray method. 在这些方法中尤其优选湿片法,因为它易于获得均匀、薄的非织造织物。 In these methods, particularly preferred wet sheet process, because it is easy to obtain a uniform, thin non-woven fabric.

认为本发明的锂离子二次电池的防止过度充电功能与隔膜结构(质地)密切相关,并且不是与组成片材(A)的材料特别相关。 Considered a lithium ion secondary battery of the present invention prevents excessive charging function diaphragm structure (texture) is closely related to, and is not particularly relevant to the sheet material (A) is. 也就是说,只要片材(A)由具有足够抗氧化性和抗还原性的材料组成就适合使用。 That is, as long as the sheet (A) made of a material having a sufficient resistance to oxidation and reducing the composition is suitable for use. 这些材料包括聚酯、芳族聚酰胺、聚苯硫醚、聚烯烃等。 These materials include polyester, aramid, polyphenylene sulfide, polyolefins and the like. 可以单独使用或者两种或更多种组合使用。 May be used alone or in combination of two or more. 组成片材(A)的材料只需具有足够的分子量以获得模塑制品,在大多数情况下适合的分子量(重均分子量:Mw)为5000或更高。 A sheet material (A) need only have a sufficient molecular weight to obtain a molded article, in most cases, a suitable molecular weight (weight average molecular weight: Mw) of 5,000 or higher.

第二种形式为平均膜厚为10-35微米、基重为10-25克/米2的多孔膜,所述多孔膜包含环绕上述片(A)并且可以被电解质溶液溶胀而又具有保持性的多孔有机聚合物膜(B)。 The second form is the average film thickness of 10-35 microns, a basis weight of the porous film 10-25 g / m 2, the porous membrane surrounding said tablet comprising (A) and an electrolyte solution can be swollen but retentive porous organic polymer film (B). 尽管所述第二种形式在防止过度充电功能上稍差于单独由片材(A)组成的隔膜的上述形式(因为它可能阻碍沉积在负极上的锂颗粒在过度充电时到达正极表面的附近),但只要满足上述条件,仍可以保证过度充电时锂离子二次电池的安全性。 Although the second form in said forms to prevent overcharging alone was somewhat inferior to the diaphragm by the sheet (A) consisting of a function (as it may impede the lithium deposited on the negative electrode surface of the particles reach the vicinity of the positive electrode during overcharge ), but as long as the above conditions are satisfied, can still guarantee that when a lithium ion secondary battery from overcharge safety. 另一方面,与第一种形式相比,第二种形式的优点在于改进了电解质溶液的保持性和更强的短路抑制性,因此它对于膜制电池是有效的从而满足关于溶液泄漏的严格条件,或者适用于隔膜为折平的结构的电池如平板形电池从而满足关于短路的严格条件。 On the other hand, compared with the first form, the second form has the advantage of improving the electrolyte solution was maintained and stronger inhibitory short circuit, it is effective for the cell membrane system to meet stringent leakage on solution conditions, or applied to the structure of the membrane is folded flat as flat-shaped battery cells to meet the stringent conditions for the shorts.

如果第二种形式的平均膜厚小于10微米并且重量小于10克/米2,不能获得隔膜的足够的强度并出现各种问题如短路。 If the average film thickness of the second form is less than 10 microns and a weight of less than 10 g / m 2, sufficient strength can not be obtained and the separator various problems such as short circuit. 对于第一种形式而言,难以获得包括3克/微米或更大的归一化的击穿强度和80克或更大的有效击穿强度。 For the first form, it is difficult to obtain comprising 3 g / m or larger normalized breakdown strength 80 g or more effective breakdown strength.

大于35微米的平均膜厚和大于25克/米2的基重不仅对于防止过度充电功能是不利的,而且导致降低电池的特性。 The average film thickness greater than 35 microns and greater than 25 g / m 2 base weight not only to prevent over-charging function is disadvantageous, but also result in reduced battery characteristics. 具体而言,有时低温特性是不需要的。 Specifically, low-temperature characteristics are sometimes unnecessary. 对于第一种形式而言,难以获得MacMullin数为10或更小并且膜厚×MacMullin数值不大于200微米的这种类型的多孔膜。 For the first form, it is difficult to obtain MacMullin number of 10 or less and the film thickness of the porous film × MacMullin this type of value is not greater than 200 microns.

如上所述,本发明的锂离子二次电池的防止过度充电功能基本上与组成隔膜的材料无关,因此多孔有机聚合物膜(B)只需是可以被电解质溶液溶胀并且具有保持性以及用于电池时具有足够的抗氧化/还原性的材料即可。 As described above, the lithium ion secondary battery of the present invention prevents overcharging function substantially independent of the material of the diaphragm, so the porous organic polymer film (B) is only the electrolyte solution may be swollen and retentive, and for When the battery has sufficient resistance to oxidation / reduction of the material can be. 从这个观点来看,适用于多孔有机聚合物膜(B)的材料包括主要由(PVdF)组成的聚偏1,1-二氟乙烯(PVdF)共聚物。 From this point of view, suitable porous organic polymer film (B) comprises a material mainly composed of (PVdF) consisting of polyvinylidene fluoride (PVdF) copolymer. 优选所述PVdF共聚物的分子量的范围为10,000至一百万的重均分子量(Mw)。 The molecular weight of the PVdF copolymer is preferably from 10,000 to one million weight average molecular weight (Mw).

在PVdF共聚物中偏1,1-二氟乙烯的适合的聚合比率范围为VdF的摩尔分数占92-98%。 In the PVdF copolymer, vinylidene fluoride suitable polymerization ratio in the range of the mole fraction of VdF accounts for 92-98%. 如果VdF的摩尔分数超过98%,所述聚合物的结晶性将太大,不仅难以形成隔膜,而且不符合需要地降低在电解质溶液中的溶胀作用。 If VdF mole fraction exceeds 98%, the crystallinity of the polymer will be too large, difficult to form not only the membrane, but does not meet the need to reduce the swelling in the electrolyte solution. 如果VdF的摩尔分数小于92%,所述聚合物的结晶性将太低,这将可能不符合需要地降低保持电解质溶液的多孔膜的机械性能和耐热性。 If VdF is less than 92% mole fraction of the crystalline polymer will be too low, which could not meet the need to reduce the electrolyte solution holding porous membrane mechanical properties and heat resistance.

作为优选的PVdF共聚物的具体例子,可提及的有由VdF、HFP和CTFE组成的三元共聚物。 Specific examples of preferred PVdF copolymer, there can be mentioned terpolymers VdF, HFP and CTFE thereof. 最优选所述共聚物的共聚组成为VdF/HFP(a)/CTFE(b)[其中(a)=2-8%重量并且(b)=1-6%重量]。 Most preferably the comonomer composition of the copolymer was VdF / HFP (a) / CTFE (b) [wherein (a) = 2-8% by weight and (b) = 1-6% by weight].

如果HFP(a)的共聚比例小于2%重量,采用无水电解质溶液的溶胀程度将出现所不符合要求地降低。 If the HFP (a) the copolymerization ratio of less than 2% by weight, using the degree of swelling of the aqueous electrolyte solution will not be satisfactorily reduced appear. 如果超过8%重量,所述膜的弹性将降低从而不能充分保持大量的电解质溶液,而当保持电解质溶液时耐热性也出现不符合要求地降低。 If more than 8% by weight, elasticity of the membrane will not be sufficiently reduced so as to retain a large amount of electrolyte solution, and when the heat resistance of the electrolyte solution holding there does not meet the requirements reduced.

优选CTFE(b)的共聚比例为1-6%重量。 Preferably CTFE (b) the copolymerization ratio of 1-6% by weight. 如果CTFE的比例小于1%重量,加入CTFE的效果将不充分,并且难以保持耐热性和提高电解质溶液的保持。 If the proportion is less than 1% by weight CTFE, CTFE was added the effect is not sufficient, and it is difficult to maintain and improve the heat resistance of the electrolyte solution holding. 如果其加入量大于6%重量,采用电解质溶液的溶胀程度将出现不符合要求地降低。 If its amount is larger than 6% by weight, the use of the degree of swelling of the electrolyte solution does not appear to meet the requirements reduced.

可以单独使用PVdF共聚物,或者它们可以作为两种或更多种不同共聚物的混合物的形式使用。 PVdF copolymer may be used alone, or they may be used as mixtures of two or more different copolymers. 如果需要,可以将它们与电解质溶液溶胀的无氟聚合物如聚丙烯腈(PAN)、聚甲基丙烯酸甲酯(PMMA)或聚环氧乙烷(PEO)进行掺混。 If desired, they can be non-fluorine polymer swollen with electrolyte solution such as polyacrylonitrile (PAN), polymethyl methacrylate (PMMA) or polyethylene oxide (PEO) were blended.

如果需要,除了片材(A)和多孔有机聚合物膜(B)外,所述多孔膜也可以含有多孔无机填料。 If desired, in addition to the sheet (A) and the porous organic polymer film (B) In addition, the porous film may contain an inorganic porous filler. 通过包括多孔无机填料,可以在不牺牲离子导电性的前提下提高膜的短路抑制性。 By including a porous inorganic filler, a short circuit can be improved suppression of the film without sacrificing the ionic conductivity of the premise. 作为适合的无机填料,可以提及的有粒径为0.1-10微米的二氧化硅、氧化铝等的多孔颗粒。 Suitable as inorganic filler, there may be mentioned a particle size of 0.1-10 microns silica, alumina, porous particles.

可以通过将片材(A)浸渍和涂布所用的聚合物溶液以形成多孔有机聚合物膜(B),然后除去溶剂来获得多孔膜。 The polymer solution can be a sheet (A) impregnating and coating used to form the porous organic polymer film (B), and then the solvent was removed to obtain a porous membrane. 可提及下面的方法作为制备多孔膜的具体方法。 The following methods may be mentioned as a specific method for preparing a porous film.

1.一种方法,其中将形成多孔有机聚合物膜(B)所用的聚合物,溶解所述聚合物并且与水相容的溶剂,相分离剂(胶凝剂或成孔剂)一起混合并溶解,将片材(A)用所得的涂布液(dope solution)进行浸溃并涂布,然后将所得的膜浸入水凝结浴中以凝结用以形成多孔的有机聚合物膜(B)的聚合物,最后洗涤并干燥以获得多孔膜。 1. A method in which an organic polymer film to form a porous (B) the polymer used, the polymer is dissolved and a solvent compatible with water, phase separation agent (gelling agent or a pore forming agent) were mixed together and dissolved, the sheet (A) were impregnated and coated with the resulting coating solution (dope solution), and the resulting film was immersed in water coagulation bath to coagulate the organic polymer to form a porous film (B) of polymer, and finally washed and dried to obtain a porous film.

2.一种方法,其中将形成多孔有机聚合物膜(B)所用的聚合物,溶解所述聚合物的挥发性溶剂和混合增塑剂溶解在一起,将片材(A)用所得的涂布液进行浸溃并涂布,然后干燥以除去挥发性溶剂,此后溶解增塑剂,然后用不会溶解用以形成多孔的有机聚合物膜(B)的聚合物的挥发性溶剂进行萃取,干燥获得多孔膜。 2. A method in which an organic polymer film to form a porous (B) the polymer used, the polymer is dissolved a volatile solvent and mixed with a plasticizer dissolved, the sheet (A) coated with the resulting cloth was subjected to dipping and coating, and then dried to remove the volatile solvent, and thereafter dissolving the plasticizer, and then does not dissolve to form a porous organic polymer film (B) is a polymer of a volatile solvent extracted, dried porous film was obtained.

3.一种方法,其中将形成多孔有机聚合物膜(B)所用的聚合物与增塑剂混合,加热所述混合物以塑化并熔化用以形成多孔有机聚合物膜(B)的聚合物并将片材(A)用这种涂布液进行浸渍并涂布,此后将所述膜冷却至坚硬,溶解增塑剂,然后用不会溶解所述形成多孔有机聚合物膜(B)所用的聚合物的挥发性溶剂进行萃取,干燥以获得多孔膜。 3. A method for the polymer, wherein the porous organic polymer film is formed (B) used in the polymer mixture with a plasticizer, heating the mixture to plasticize and melt to form a porous organic polymer film (B) of and the sheet (A) was impregnated with this coating liquid and the coating, after which the film is cooled to a hard, dissolve the plasticizer, and then does not dissolve the porous organic polymer film is formed (B) used volatile polymer solvent extracted, and dried to obtain a porous film.

本发明隔膜的第二种形式优于第一种形式的地方在于电解质溶液的浸渍和保持。 The second form of the present invention is superior to the first form of the diaphragm place is impregnated with the electrolytic solution and holding. 可以通过浸渍电解质溶液的量来评定电解质溶液的浸渍。 Can be assessed by the amount of the electrolytic solution impregnated electrolytic solution impregnated. 在本发明的整篇说明书中,电解质溶液的浸渍量通过浸渍的电解质溶液对隔膜的干重的百分率来代表。 Throughout the description of the present invention, the amount of impregnation of the electrolytic solution of the electrolytic solution impregnating the separator of the dry weight percentage represented by. 具体而言,隔膜对电解质溶液的保持性可以通过离心采用无水电解质溶液浸渍的隔膜来进行评定,其中离心力为1400×g(重力加速度),离心20分钟以除去弱保持的无水电解质溶液。 Specifically, the separator for holding the electrolyte solution can be improved by using a centrifugal separator nonaqueous electrolyte impregnation solution to be assessed, wherein the centrifugal force of 1400 × g (acceleration of gravity), centrifuged for 20 minutes to remove weakly held non-aqueous electrolyte solution. 在本发明的整篇说明书中,电解质溶液保持性将由离心后的隔膜重量对离心前的隔膜重量的重量百分比来代表。 Throughout the description of the present invention, the electrolyte solution retention after centrifugation by weight of the weight percentage of the centrifugal separator before the separator is represented by weight. 优选电解质溶液的保持性为至少70%重量,更优选至少80%重量。 Preferably the electrolyte solution retention of at least 70% by weight, more preferably at least 80% by weight.

考虑到电池制备中的加工性,上述用于本发明的锂离子二次电池的隔膜优选具有至少1.5×102N/m,尤其至少3.0×102N/m的安全限应力。 Taking into account the battery prepared in workability, as described above for the lithium ion secondary battery separator of the present invention preferably has at least 1.5 × 102N / m, in particular at least 3.0 × 102N / m of the stress safety limits. 所述安全限应力标示弹性极限强度和可以处理所述膜的拉伸力的程度,较大的值表明更容易处理并且具有更高的生产率。 The degree of security confinement stress Flag elastic limit strength and can handle the tensile force of the film, and higher values indicate easier to handle and has higher productivity.

所述安全限应力通常由拉伸测试进行确定。 The safety limit stresses are usually determined by tensile testing. 根据本发明,由隔膜切出1cm×3cm的条、通过拉伸速率为20mm/min的张力进行张力测试获得的张力-应变曲线来计算所述安全限应力。 According to the present invention, a diaphragm strips 1cm × 3cm was cut out of, the tension obtained by stretching a tensile test rate of 20mm / min Tension - strain curve to calculate the stress safety limits.

优选本发明隔膜的热变形温度为150℃或更高,更优选为170℃或更高。 Heat distortion temperature of the separator of the present invention is preferably 150 ℃ or higher, more preferably 170 ℃ or higher. 可以通过热力学分析(TMA)评定所述热变形温度。 By thermodynamic analysis (TMA) assess the heat distortion temperature. 通过TMA方法对热变形温度的评定可如下进行:从隔膜切出4mm宽的条,其上施加0.01N的负荷,以速率为10℃/min升高温度时,当出现至少2%的长度变化(伸长)时的温度确定为热变形温度。 By TMA method of assessing the thermal deformation temperature can be carried out as follows: the membrane was cut out from 4mm wide strips, 0.01N load applied thereto, at a rate of 10 ℃ / min while raising the temperature, when there is at least 2% of the change in length temperature (elongation) when determined as the thermal deformation temperature.

[无水电解质]如锂离子二次电池常用的那样,用于本发明的锂离子二次电池的无水电解质可以为锂盐在无水溶剂中的溶液。 [Anhydrous Electrolyte] The lithium ion secondary battery as commonly used lithium ion secondary battery of the present invention may be non-aqueous electrolyte solution of lithium salt in an anhydrous solvent is.

作为无水溶剂的具体例子,可以提及的有碳酸异丙烯酯(PC)、碳酸亚乙酯(EC)、碳酸亚丁酯(BC)、碳酸亚乙烯酯(VC)、碳酸二甲酯(DMC)、碳酸二乙酯(DEC)、碳酸甲乙酯(MEC)、1,2-二甲氧基乙烷(DME)、1,2-二乙氧基乙烷(DEE)、γ-丁内酯(γ-BL)、环丁砜和乙腈。 Specific examples of the aqueous solvent, there may be mentioned propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), vinylene carbonate (VC), dimethyl carbonate (DMC ), diethyl carbonate (DEC), methyl ethyl carbonate (MEC), 1,2- dimethoxyethane (DME), 1,2- diethoxyethane (DEE), γ- butyrolactone ester (γ-BL), sulfolane and acetonitrile. 可以单独使用这些无水溶剂或者组合两者或更多种进行使用。 These aqueous solvents may be used alone or in combination of two or more species were used. 尤其适用的为选自PC、EC、γ-BL、DMC、DEC、MEC和DME中的任何一种或多种溶剂。 Especially suitable for the selected PC, EC, γ-BL, DMC, DEC, MEC and DME any one or more solvents.

作为溶于这些无水溶剂中的锂盐,可以提及的有高氯酸锂(LiClO4)、六氟磷酸锂(LiPF6)、四氟硼酸锂(LiBF4)、六氟砷酸锂(LiAsF6)、三氟磺酸锂(CF3SO3Li)、全氟甲基磺酰亚胺锂[LiN(CF3SO2)2]和全氟乙基磺酰亚胺锂[LiN(C2F5SO2)2],但不限于此。 Is dissolved in an anhydrous solvent such as lithium salt, there may be mentioned lithium perchlorate (LiClO4), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), trifluoromethyl sulfonic lithium (CF3SO3Li), perfluoromethyl sulfonyl imide lithium [LiN (CF3SO2) 2] and perfluoro ethyl imide lithium [LiN (C2F5SO2) 2], but is not limited thereto. 也可以两种或更多种进行组合使用。 Or two or more kinds used in combination. 优选溶解的锂盐的浓度的范围为0.2-2M(摩尔/升)。 Range preferably dissolved lithium salt concentration of 0.2-2M (mol / liter).

[锂离子二次电池的制备]对于制备本发明的锂离子二次电池的方法没有特别的限定,可以采用任何公众已知的制备锂离子二次电池的方法。 [Preparation of lithium ion secondary battery] For a method for producing a lithium ion secondary battery of the present invention is not particularly limited, and may prepare a lithium ion secondary battery of any method known to the public.

具体而言,一种常用的方法包括在壳体内放置通过隔膜耦合的正极和负极,随后往其中注入电解质并将其密封。 Specifically, a commonly used method includes placing a positive electrode and the negative electrode through a separator coupled within the housing, and then an electrolyte is injected thereto and sealed. 优选真空注射作为注射电解质的方法,但是对其没有特别的限制。 Preferably a vacuum injection method as an injection of the electrolyte, but is not particularly limited. 也可以将耦合的电极在置于壳体之前用电解质溶液进行浸溃。 May be coupled to the electrodes prior to be disposed in the housing with an electrolyte solution impregnated.

对于膜制电池而言,其中的壳体为由铝-塑料层压膜组成的组件,优选通过粘合将电极和隔膜结合在一起。 For the purposes of cell membrane system, wherein the housing by an aluminum - component composed of plastic laminate film, preferably by bonding together the electrode and the separator. 在这种情况下,优选所述隔膜为前述第二种形式的多孔膜。 In this case, it is preferable for the second mode of the diaphragm of a porous membrane. 隔膜和电极的粘合主要通过热压粘合来完成,这可在没有电解质的干态或含有电解质的湿态下实施。 Bonding the diaphragm and the electrode mainly accomplished by thermocompression bonding, which may be practiced in the absence of an electrolyte containing an electrolyte dry or wet state. 当隔膜和电极之间的粘合强度是令人满意时,可以在没有热压粘合步骤下制备所述电池。 When the adhesive strength between the separator and the electrode is satisfactory, can be prepared in the absence of the battery under the thermocompression bonding step.

[锂离子二次电池]对于本发明的锂离子二次电池的形状没有特别的限制,它可以具有任何形状,如圆柱状、棱柱状、片状或钮扣状。 [Lithium ion secondary battery] not for the present invention, the shape of the lithium ion secondary battery is not particularly limited, it may have any shape, such as cylindrical, prismatic, sheet-like or button-shaped.

所述壳体可以为钢筒、铝筒或由铝-塑料层压膜制成的组件,但不限于此。 The housing may be a steel drum, made of aluminum or aluminum cylinder - component made of a plastic laminate film, but is not limited thereto.

当本发明的锂离子二次电池显示出前述的防止过度充电功能时,充电方法使引入的电能以焦耳热的形式从所述系统释放出来。 When the lithium ion secondary battery of the present invention exhibit the aforementioned function to prevent overcharging, charging method so that the introduction of electrical energy in the form of Joule heat released from the system. 这种焦耳热可以表达为(充电电流×电池电压)。 This Joule heating can be expressed as (battery charging current × voltage). 由于在显示防止过度充电功能时电池电压基本恒定,因此Ic是影响焦耳热的主要因素。 Since the function of the display to prevent overcharging the battery voltage is substantially constant, so Ic is the main factor of Joule heat. 尽管焦耳热取决于所用的Ic,但由其引起的电池内部的温度升高可能危及电池如燃烧。 Although the Joule heat depending on the Ic, but its temperature inside the battery rises due to combustion may endanger the battery. 因此根据所用的Ic,选择本发明锂离子二次电池的形状以获得令人满意的热释放效率。 Thus depending on the Ic, select the shape of the lithium ion secondary battery of the present invention is to obtain a satisfactory heat release efficiency. 从改进热释放效率的角度来看,优选采用铝-塑料层压组件作为护套的膜制电池。 Improved heat release efficiency from the point of view, preferably aluminum - plastic film laminate assembly as a sheath system battery. 也可以采用在电池上安装辐射板的方法。 May be used as a radiation plate installed in the battery method.

由于前述的防止过度充电功能,本发明的锂离子二次电池抑制了通过电解质溶液的氧化分解而生成气体。 Thanks to the aforementioned function to prevent excessive charging, the lithium ion secondary battery of the present invention suppresses gas generated by oxidative decomposition of the electrolyte solution. 从电池的膨胀来看,膜制电池需要严格条件,从这个观点来看,优选本发明的锂离子二次电池采用膜制电池的形式。 From the expansion of the cell, the cell membrane system requires strict conditions, from this viewpoint, a lithium ion secondary battery of the invention preferably takes the form of film-made batteries. 此外,尽管在常规的锂离子二次电池中通常安装安全排口,但由于在本发明的锂离子二次电池的过度充电中的气体发生受到抑制,可以在不提供安全排口的前提下充分保证过度充电时的安全性。 Moreover, although the safety discharge port is typically installed in a conventional lithium ion secondary battery, but since the overcharging of the lithium ion secondary battery of the present invention the gas generating suppressed, can be made without providing sufficient security and discharge port premise ensure safety during overcharge. 但是,当然如果存在安全排口,安全性将得到进一步提高。 However, of course, if there is a security and discharge port, security will be further enhanced.

由于焦耳热的问题,根据所用的充电电流Ic,本发明的锂离子二次电池的过度充电时的安全性在某些情况下可能得不到保证。 Problems due to the Joule heat, depending on the charging current Ic, safety for lithium ion secondary battery of the present invention over charging in some cases may not be assured. 原则上对于高的充电电流(速率),不优选本发明的锂离子二次电池的防止过度充电的功能。 In principle, for a high charging current (rate), the lithium ion secondary battery of the present invention prevents undesirable excessive charging function. 即使采用公众已知的用于提高过度充电时的安全性的各种添加剂仍不足以保证高充电电流(速率)的安全性。 Even with a publicly known various additives for improving the safety during overcharge is still insufficient to ensure a high charging current (rate) security. 由于本发明的锂离子二次电池的防止过度充电的功能基于与使用公众已知的添加剂原理上不同的机制,所以也可以使用这些添加剂。 Since the lithium ion secondary battery of the present invention to prevent excessive charging function based on the principle of using publicly known additives different mechanisms, it is also possible to use these additives. 因此,组合使用这些公众已知的添加剂足以保证过度充电时的安全性,即使在采用高充电电流(速率)下也是如此。 Thus, a combination of these publicly known additives sufficient to guarantee the security of over-charging, even when a high charging current (rate) under well.

[电池组]本发明的电池组装配了至少一个本发明的锂离子二次电池和热敏传感器(热传感器)或热敏开关(热敏电阻和/或PTC)。 [Battery] battery pack assembly of the present invention is a lithium ion secondary battery and thermal sensors (heat sensors) or thermal switch of the present invention, at least one (thermistor and / or PTC).

如上所述,当本发明的锂离子二次电池的防止过度充电功能起作用时将产生焦耳热。 As described above, when the lithium ion secondary battery of the present invention to prevent overcharging the Joule heat is generated when the function is activated. 可以通过热量探测到本发明的锂离子二次电池的过度充电,因此从安全性的角度来看,在电池组中装配热敏传感器(热传感器)或热敏开关(热敏电阻和/或PTC)是有效的。 Can be detected by the excessive heat in rechargeable lithium ion secondary battery of the present invention, and therefore from a security point of view, in the battery pack assembly of thermal sensor (thermal sensors) or thermal switch (thermistor and / or PTC ) is effective.

尽管在本发明的锂离子二次电池中采用热敏传感器(热传感器)或热敏开关(热敏电阻和/或PTC)可以充分保证过度充电时的安全性,但也可以装配保护电路。 Despite the use of a thermal sensor (thermal sensors) or thermal switch (thermistor and / or PTC) in the lithium ion secondary battery of the present invention can fully guarantee the safety of over-charging, but also can be equipped with protection circuits. 通过装配保护电路可进一步改进所述电池的安全性。 By mounting the protective circuit may further improve the safety of the battery.

[充电方法]本发明的充电方法包括通过恒定的电流法对本发明的锂离子二次电池进行充电,根据下面的至少一项对完成充电进行判断:电池温度的升高、电池电压的下降或电池电压的振荡。 [Charging Method] The method of the present invention comprises a charge by a constant current method of a lithium ion secondary battery of the present invention will be charged according to the following the completion of charging at least one pair of judgment: battery temperature increase, battery voltage drop or battery voltage oscillation.

本发明的锂离子二次电池的特征在于不仅通过上述的防止过度充电功能保证过度充电时的安全性,而且在此后能够进行放电。 Lithium ion secondary battery of the present invention is characterized in that not only ensure the safety of over-charging by the above over-charging prevention, and thereafter can be discharged. 可以通过由于焦耳热的电池温度的升高、电池电压的下降或电池电压的振荡来探测到防止过度充电功能的启动。 Since the Joule heat by the battery temperature, the battery voltage drop or battery voltage oscillation to detect prevent excessive charging starts. 探测到防止过度充电的功能意味着电池充电已完全。 Probe to prevent excessive charging function means that the battery is fully charged. 因此,可以进行恒定的电流充电,其中通过电池温度的升高、电池电压的下降或电池电压的振荡来判断充电的完成。 Thus, constant current charging can be performed, by which the battery temperature, the battery voltage drop or battery voltage oscillation to determine completion of charging.

但是,本发明锂离子二次电池的充电方法不限于前述方法,可以采用任何常用的方法,如恒定电流/恒定电压的充电方法。 However, the present invention is a lithium ion secondary battery charging method is not limited to the foregoing method, may be employed any conventional method, such as a charging method of constant-current / constant voltage.

[电气/电子设备]本发明还提供装配有本发明的锂离子二次电池或锂离子二次电池组的电气/电子设备。 [Electric / Electronic Equipment] The present invention also provides an electrical assembly of the present invention is a lithium ion secondary battery or a lithium ion secondary battery pack / electronics.

本发明的锂离子二次电池或锂离子二次电池组可适用于各种便携式电子设备中,如蜂窝式电话或膝上型计算机。 The present invention is a lithium ion secondary battery or a lithium ion secondary battery pack can be applied to various portable electronic devices, such as a cellular telephone or a laptop computer. 特别是与普通的恒定电流/恒定电压充电法相比,采用上述的充电方法可以大大地缩短充电时间。 Especially when compared with the conventional constant current / constant voltage charging method, the charging method using the above can greatly shorten the charging time.

以下将通过实施例更详细地对本发明进行解释。 Below in more detail of the present invention will be explained by way of examples.

[隔膜]实施例1将细度为0.22dtex的粘合剂聚对苯二甲酸乙二醇酯(PET)短纤维(平均纤维直径:约4.5微米)与细度为0.33dtex的取向和结晶的PET短纤维(平均纤维直径:约5.5微米)以4/6的重量比进行掺混,通过湿片法形成基重为12g/m2的膜并通过200℃的压延机辊压以获得非织造织物片材。 [Separator] Example 1 having a fineness of 0.22dtex adhesive polyethylene terephthalate (PET) staple fiber (average fiber diameter: about 4.5 m) with a fineness of 0.33dtex and crystalline orientation PET staple fibers (average fiber diameter: about 5.5 micrometers) with a weight ratio of 4/6 are blended, a basis weight of 12g / m2 by a wet film-forming method and sheet through the calender roll 200 ℃ to obtain a nonwoven fabric sheet. 所得片材的性质如下。 Properties of the resulting sheet are as follows.

平均膜厚:18微米,透气性:0.07秒,归一化的击穿强度:5.0克/微米(90克),MacMullin数:5.0(MacMullin数×膜厚值=90微米)。 Average thickness: 18 m, air permeability: 0.07 seconds, normalized breakdown strength: 5.0 g / m (90 g), MacMullin Number: 5.0 (MacMullin number × the film thickness value = 90 microns).

实施例2用针在聚丙烯(PP)细孔膜(CELGARD TM2400,Celgard Co.的产品)上均匀开许多直径为2微米的孔。 Example 2 A needle embodiment in polypropylene (PP) uniform open pore membrane (CELGARD TM2400, Celgard Co. product) on a number of holes having a diameter of 2 microns. 所得片材的性质如下。 Properties of the resulting sheet are as follows.

平均膜厚:25微米,基重:13.5克/米2,透气性:80秒,归一化的击穿强度:12克/微米(300克),MacMullin数:5.8(MacMullin数×膜厚值=145微米)。 Average thickness: 25 microns, basis weight: 13.5 g / m 2, air permeability: 80 seconds, normalized breakdown strength: 12 g / m (300 g), MacMullin Number: 5.8 (MacMullin number × the film thickness value = 145 microns).

实施例3将细度为1.22dtex的粘合剂PET短纤维(平均纤维直径:约11微米)与细度为0.55dtex的取向和结晶的PET短纤维(平均纤维直径:约7微米)以5/5的重量比进行掺混,通过湿片法形成基重为12g/m2的膜并通过160℃的压延机辊压以获得非织造织物片材。 Example 3 The fineness of 1.22dtex adhesive PET staple fibers (average fiber diameter: about 11 microns) with a fineness of 0.55dtex the orientation and crystallinity of the PET staple fibers (average fiber diameter: about 7 m) to 5 weight / 5 ratio in blending, a basis weight of 12g / m2 by a wet film-forming method and sheet through the calender roll 160 ℃ to obtain a nonwoven fabric sheet. 所得片材的性质如下。 Properties of the resulting sheet are as follows.

平均膜厚:18微米,透气性:0.04秒,归一化的击穿强度:6.5克/微米(117克),MacMullin数:9.0(MacMullin数×膜厚值=162微米)。 Average thickness: 18 m, air permeability: 0.04 seconds, normalized breakdown strength: 6.5 g / m (117 g), MacMullin Number: 9.0 (MacMullin number value = 162 × film thickness m).

在60℃下,将由VdF∶HFP∶CTFE=95.5∶2.3∶2.2(摩尔比)组成的PVdF共聚物溶于含有N,N-二甲基乙酰胺(DMAc)和平均分子量为400的聚丙二醇(PPG)以6/4(重量比)的混合溶剂中,从而制备共聚物浓度为14%重量的成膜涂布液。 At 60 ℃, by VdF:HFP:CTFE = 95.5:2.3:2.2 (molar ratio) composition comprising PVdF copolymer was dissolved in N, N- dimethylacetamide (DMAc) and an average molecular weight of 400, polypropylene glycol ( PPG) to (weight ratio) mixed solvent of 6/4 to prepare a copolymer concentration of 14% by weight of film-forming coating liquid. 将得到的涂布液用于浸渍和涂布上述非织造织物片材,然后将所得的膜浸渍在溶剂浓度为40%重量的水溶液中,凝结,随后洗涤并干燥获得多孔膜。 The coating solution was used to impregnate and coat the non-woven fabric sheet, and then the resultant membrane was immersed in a solvent at a concentration of 40% by weight of an aqueous solution, coagulation, followed by washing and drying to obtain a porous film. 所得多孔膜的性质如下。 Properties of the resulting porous film is as follows.

平均膜厚:26微米,基重:21.1克/米2,归一化的击穿强度:5.5克/微米(144克),MacMullin数:5.9(MacMullin数×膜厚值=153微米),安全限应力:3.5×102N/m。 Average thickness: 26 microns, basis weight: 21.1 g / m 2, normalized breakdown strength: 5.5 g / m (144 g), MacMullin Number: 5.9 (MacMullin number value = 153 × film thickness m), safety Limit stress: 3.5 × 102N / m.

实施例4通过干片法,采用细度为0.9dtex的结晶间芳酰胺短纤维(平均纤维直径:约10微米)形成基重为15g/m2的膜并通过320℃的压延机辊压以获得非织造织物片材。 Example 4 by a dry sheet process, using a fineness of between 0.9dtex crystalline aramid short fibers: a basis weight of 15g / m2 of film (average fiber diameter of about 10 microns) is formed by a calender roll pressure to obtain 320 ℃ nonwoven fabric sheet. 所得片材的性质如下。 Properties of the resulting sheet are as follows.

平均膜厚:30微米,透气性:0.04秒,归一化的击穿强度:5.6克/微米(95克),MacMullin数:5.8(MacMullin数×膜厚值=98.6微米)。 Average thickness: 30 m, air permeability: 0.04 seconds, normalized breakdown strength: 5.6 g / m (95 g), MacMullin Number: 5.8 (MacMullin number × the film thickness value = 98.6 [mu] m).

在60℃下,将由VdF∶HFP∶CTFE=95.5∶2.3∶2.2(摩尔比)组成的PVdF共聚物溶于含有N,N-二甲基乙酰胺(DMAc)和平均分子量为400的聚丙二醇(PPG)以6/4(重量比)的混合溶剂中,从而制备共聚物浓度为10%重量的成膜涂布液。 At 60 ℃, by VdF:HFP:CTFE = 95.5:2.3:2.2 (molar ratio) composition comprising PVdF copolymer was dissolved in N, N- dimethylacetamide (DMAc) and an average molecular weight of 400, polypropylene glycol ( PPG) to (weight ratio) mixed solvent of 6/4 to prepare a copolymer concentration of 10% by weight of film-forming coating liquid. 将得到的涂布液用于浸渍和涂布上述非织造织物片材,然后将所得的膜浸渍在溶剂浓度为40%重量的水溶液中,凝结,随后洗涤并干燥获得多孔膜。 The coating solution was used to impregnate and coat the non-woven fabric sheet, and then the resultant membrane was immersed in a solvent at a concentration of 40% by weight of an aqueous solution, coagulation, followed by washing and drying to obtain a porous film. 所得多孔膜的性质如下。 Properties of the resulting porous film is as follows.

平均膜厚:34微米,基重:20.9克/米2,归一化的击穿强度:9.7克/微米(330克),MacMullin数:4.6(MacMullin数×膜厚值=156微米),安全限应力:6.4×102N/m。 Average thickness: 34 microns, basis weight: 20.9 g / m 2, normalized breakdown strength: 9.7 g / m (330 g), MacMullin Number: 4.6 (MacMullin number value = 156 × film thickness m), safety Limit stress: 6.4 × 102N / m.

实施例5将细度为0.22dtex的粘合剂PET短纤维(平均纤维直径:约4.5微米)与细度为0.55dtex的结晶间芳酰胺短纤维(平均纤维直径:约7微米)以4/6的重量比进行掺混,并通过湿片法形成基重为11g/m2的膜并通过200℃的压延机辊压以获得非织造织物片材。 Example 5 The fineness of 0.22dtex adhesive PET staple fibers (average fiber diameter: about 4.5 m) with a fineness of between 0.55dtex crystalline aramid short fibers (average fiber diameter: about 7 m) to 4 / 6 wt basis weight 11g / m2 of membrane blending ratio, and is formed by a wet sheet process by calender roll 200 ℃ to obtain a nonwoven fabric sheet. 所得片材的性质如下。 Properties of the resulting sheet are as follows.

平均膜厚:17微米,透气性:0.06秒,归一化的击穿强度:5.6克/微米(95克),MacMullin数:5.8(MacMullin数×膜厚值=99微米)。 Average thickness: 17 m, air permeability: 0.06 seconds, normalized breakdown strength: 5.6 g / m (95 g), MacMullin Number: 5.8 (MacMullin number × the film thickness value = 99 microns).

采用如实施例3中制备的相同的涂布液对这种非织造织物片材进行浸渍并涂布后,将所得的膜浸渍在溶剂浓度为40%重量的水溶液中,凝结,随后洗涤并干燥获得多孔膜。 As described in the same coating solution prepared in Example 3 of this non-woven fabric sheet was impregnated and coated, the resultant membrane was immersed in a solvent concentration of 40% by weight of an aqueous solution, coagulation, followed by washing and drying porous film was obtained. 所得多孔膜的性质如下。 Properties of the resulting porous film is as follows.

平均膜厚:24微米,基重:16.7克/米2,归一化的击穿强度:5.0克/微米(120克),MacMullin数:5.4(MacMullin数×膜厚值=130微米),安全限应力:3.5×102N/m。 Average thickness: 24 microns, basis weight: 16.7 g / m 2, normalized breakdown strength: 5.0 g / m (120 g), MacMullin Number: 5.4 (MacMullin number × the film thickness value = 130 microns), safety Limit stress: 3.5 × 102N / m.

实施例6在60℃下,将由VdF∶HFP∶CTFE=95.5∶2.3∶2.2(摩尔比)组成的PVdF共聚物溶于含有N,N-二甲基乙酰胺(DMAc)和平均分子量为400的聚丙二醇(PPG)以6.5/3.5(重量比)的混合溶剂中,从而制备共聚物浓度为12%重量的成膜涂布液。 PVdF copolymer of Example 6 at 60 ℃, by VdF:HFP:CTFE = 95.5:2.3:2.2 (molar ratio) dissolved in the composition containing N, N- dimethylacetamide (DMAc) and an average molecular weight of 400 polypropylene glycol (PPG) to (weight ratio) of 6.5 / 3.5 mixture solvent, thereby preparing a copolymer concentration of 12% by weight of film-forming coating liquid. 将得到的涂布液用于浸渍和涂布实施例1中形成的非织造织物片材,然后将所得的膜浸渍在溶剂浓度为40%重量的水溶液中,凝结,随后洗涤并干燥获得多孔膜。 The coating solution was used to impregnate and coat the non-woven fabric sheet in Example 1 was formed, and then the resultant membrane was immersed in a solvent at a concentration of 40% by weight of an aqueous solution, coagulation, followed by washing and drying to obtain a porous membrane . 所得多孔膜的性质如下。 Properties of the resulting porous film is as follows.

平均膜厚:24微米,基重:19.7克/米2,归一化的击穿强度:6.3克/微米(151克),MacMullin数:6.5(MacMullin数×膜厚值=156微米),安全限应力:3.8×102N/m。 Average thickness: 24 microns, basis weight: 19.7 g / m 2, normalized breakdown strength: 6.3 g / m (151 g), MacMullin Number: 6.5 (MacMullin number value = 156 × film thickness m), safety Limit stress: 3.8 × 102N / m.

实施例7将细度为1.22dtex的粘合剂PET短纤维(平均纤维直径:约11微米)与细度为0.11dtex的取向和结晶的PET短纤维(平均纤维直径:约3.5微米)以4/6的重量比进行掺混,通过湿片法形成基重为12g/m2的膜并通过130℃的压延机辊压以获得非织造织物片材。 Example 7 fineness of 1.22dtex adhesive PET staple fibers (average fiber diameter: about 11 microns) with a fineness of 0.11dtex the orientation and crystallinity of PET staple fibers (average fiber diameter: about 3.5 microns) to 4 w / ratio of 6 blended, a basis weight of 12g / m2 by a wet film-forming method and sheet through the calender roll 130 ℃ to obtain a nonwoven fabric sheet. 所得片材的性质如下。 Properties of the resulting sheet are as follows.

平均膜厚:14微米,透气性:0.60秒,归一化的击穿强度:8.9克/微米(124克),MacMullin数:5.0(MacMullin数×膜厚值=70微米)。 Average thickness: 14 m, air permeability: 0.60 seconds, normalized breakdown strength: 8.9 g / m (124 g), MacMullin Number: 5.0 (MacMullin number × the film thickness value = 70 microns).

采用如实施例3中制备的相同的涂布液对这种非织造织物片材进行浸渍并涂布后,将所得的膜浸渍在溶剂浓度为40%重量的水溶液中,凝结,随后洗涤并干燥获得多孔膜。 As described in the same coating solution prepared in Example 3 of this non-woven fabric sheet was impregnated and coated, the resultant membrane was immersed in a solvent concentration of 40% by weight of an aqueous solution, coagulation, followed by washing and drying porous film was obtained. 所得多孔膜的性质如下。 Properties of the resulting porous film is as follows.

平均膜厚:24微米,基重:18.8克/米2,归一化的击穿强度:6.8克/微米(164克),MacMullin数:4.9(MacMullin数×膜厚值=118微米),安全限应力:3.3×102N/m。 Average thickness: 24 microns, basis weight: 18.8 g / m 2, normalized breakdown strength: 6.8 g / m (164 g), MacMullin Number: 4.9 (MacMullin number value = 118 × film thickness m), safety Limit stress: 3.3 × 102N / m.

对实施例1-7的隔膜的热变形温度等进行测量,得到的结果列于下面表1。 Heat distortion temperature and the like of the membrane of Examples 1-7 were measured, the results obtained are shown in Table 1 below.

表1 Table 1

比较实施例1所用的隔膜为聚丙烯(PP)细多孔膜(CELGARD TM2400,CelgardCo.的产品)。 Comparative Examples separator used in Example 1 as polypropylene (PP) fine porous film (CELGARD TM2400, CelgardCo. Of product). 膜的性质如下。 Properties of the film are as follows.

平均膜厚:25微米,基重:14.8克/米2,透气性:350秒,归一化的击穿强度:15.2克/微米(380克),MacMullin数:6.5(MacMullin数×膜厚值=163微米)。 Average thickness: 25 microns, basis weight: 14.8 g / m 2, air permeability: 350 seconds, normalized breakdown strength: 15.2 g / m (380 g), MacMullin Number: 6.5 (MacMullin number × the film thickness value = 163 microns).

比较实施例2将厚度为0.9dtex的结晶的间芳族聚酰胺短纤维(平均纤维直径:约10微米)与间芳酰胺原纤(fibrit)(合成的浆液颗粒)以8/2的重量比进行掺混,通过湿片法形成基重为30克/米2的膜,然后通过320℃的压延机辊压以获得纸状片材。 Comparative Example 2 having a thickness of 0.9dtex crystals of meta-aromatic polyamide staple fibers (average fiber diameter: about 10 microns) and between the aramid fibrils (fibrit) (Synthesis of slurry particles) with a weight ratio of 8/2 blended, sheet was formed by a wet film basis weight of 30 g / m 2, and then through the calender roll 320 ℃ to obtain a paper-like sheet. 得到的片材的性质如下。 Properties of the obtained sheet is as follows.

平均膜厚:35微米,透气性:38秒,归一化的击穿强度:16克/微米(550克),MacMullin数:18.0(MacMullin数×膜厚值=630微米)。 Average thickness: 35 m, air permeability: 38 seconds, normalized breakdown strength: 16 g / m (550 g), MacMullin Number: 18.0 (MacMullin number value = 630 × film thickness m).

比较实施例3使用PET作为原料形成平均纤维直径为1.5微米,基重为35克/米2的熔体喷射法非织造织物膜。 3 using PET average fiber diameter of 1.5 microns, a basis weight of 35 g / melt-blown nonwoven fabric as a raw material film is formed m2 Comparative Example. 将所述非织造织物通过130℃的压延机辊压形成50微米的膜。 The nonwoven fabric by the calender rolls 130 ℃ membrane pressure of 50 microns is formed. 所述非织造织物的性质如下。 Properties of the nonwoven fabric as follows.

透气性:40秒,归一化的击穿强度:5.5克/微米(275克),MacMullin数:3.8(MacMullin数×膜厚值=190微米)。 Air permeability: 40 seconds, normalized breakdown strength: 5.5 g / m (275 g), MacMullin Number: 3.8 (MacMullin number value = 190 × film thickness m).

采用如实施例3中制备的相同的涂布液对这种非织造织物片材进行浸渍和涂布后,将所得的膜浸渍在溶剂浓度为40%重量的水溶液中,凝结,随后洗涤并干燥获得多孔膜。 After using the same coating solution as described in Example 3 was of such non-woven fabric sheet was impregnated and coated, the resultant membrane was immersed in a solvent at a concentration of 40% by weight of an aqueous solution, coagulation, followed by washing and drying porous film was obtained. 所得多孔膜的性质如下。 Properties of the resulting porous film is as follows.

平均膜厚:60微米,基重:43.5克/米2,归一化的击穿强度:60克/微米(360克),MacMullin数:3.3(MacMullin数×膜厚值=198微米)。 Average thickness: 60 microns, basis weight: 43.5 g / m 2, normalized breakdown strength: 60 g / m (360 g), MacMullin Number: 3.3 (MacMullin number value = 198 × film thickness m).

[钮扣型(币型)电池的评定]实施例8[正极]采用具有6%重量的PVdF的N-甲基吡咯烷酮(NMP)溶液制备正极浆糊,包括89.5重量份的钴酸锂粉(LiCoO2,Nippon ChemicalIndustrial Co.,Ltd.的产品)、4.5重量份的乙炔黑和6重量份(干重)的PVdF。 [Button-type (coin type) battery evaluation] Example 8 [positive] of N- methylpyrrolidone using PVdF having 6% by weight of the positive electrode paste (NMP) to prepare a solution comprising 89.5 parts by weight of a lithium cobaltate powder ( LiCoO2, Nippon ChemicalIndustrial Co., Ltd. product), 4.5 parts by weight of acetylene black and 6 parts by weight (dry weight) of the PVdF. 将得到的浆糊涂布至20微米厚的铝箔上并干燥,然后压制获得97微米厚的正极。 The adhesive coating 20 microns thick aluminum foil obtained and dried, and then pressed to obtain a positive electrode 97 microns thick.

由正极重量计算的正极的总锂量Qp为5.4mAh/cm2。 The total amount of lithium from the positive electrode to the positive electrode weight of Qp 5.4mAh / cm2.

[负极]采用具有6%重量的PVdF的NMP溶液制备负极浆糊,包括87重量份作为负极活性材料的中间相碳微珠(MCMB,Osaka GasChemical Co.,Ltd.的产品)粉、3重量份的乙炔黑和10重量份(干重)的PVdF。 [The negative electrode] The negative electrode paste was prepared with an NMP solution of 6% by weight of PVdF, comprising 87 parts by weight of a negative electrode active material of mesophase carbon microbeads (MCMB, Osaka GasChemical Co., Ltd. Product) powder, 3 parts by weight acetylene black and 10 parts by weight (dry weight) of the PVdF. 将得到的浆糊涂布至18微米厚的铜箔上并干燥,然后压制获得90微米厚的正极。 The paste was applied to the copper foil to 18 m thick and dried, and then pressed to obtain a positive electrode 90 microns thick.

测量三个电极电池,所述负极上可以涂布的锂量Qn为2.6mAh/cm2。 Measuring the three-electrode cell, the amount of lithium on the negative electrode can be coated Qn is 2.6mAh / cm2.

[钮扣型(币型)电池的制备]将上述正极和负极冲压成直径为14毫米的环,将实施例1-7中制备的隔膜冲压成直径为16毫米后使用。 [Button-type (coin type) battery Preparation] The above-described positive electrode and the negative electrode is punched into a ring having a diameter of 14 mm, the embodiment of the membrane prepared in Examples 1-7 punched to a diameter of 16 mm after use. 将正极和负极各自通过隔膜连接起来,用电解质(电解质溶液)浸溃并铸封在电池壳体内。 The positive and negative electrodes are each connected via a separator, an electrolyte (electrolyte solution) and potting impregnated in a battery casing. 所用的电解质溶液为1M的LiPF6EC/DEC(1/1重量比)。 Electrolyte solution used was a 1M LiPF6EC / DEC (1/1 weight ratio). 电池壳尺寸为CR2032。 Battery shell size CR2032.

[过度充电的评定]通过以下操作实施对各种制备的钮扣电池的过度充电的评定:在以下条件下测量一个充电/放电循环:恒定的电流/恒定的电压充电8小时,充电的电流密度为0.52mA/cm2,充电电压最高可达4.2伏,在放电电流密度为0.52mA/cm2下以恒定电流放电,截止值为2.75伏;此后在以下条件下实施过度充电:以2.6mA/cm2的充电电流密度进行恒定电流充电10小时;在过度充电后静置2小时后,在以下条件下实施放电:放电电流密度为0.52mA/cm2,截止值为2.75伏。 [Evaluation overcharge] by the following various embodiments of the preparation of a button battery overcharge Evaluation: measurement under the following conditions a charge / discharge cycle: constant current / constant voltage charging for 8 hours, charging current density of 0.52mA / cm2, the charging voltage of up to 4.2 volts, the discharge current density of 0.52mA / cm2 at a constant current discharge, the cutoff value was 2.75 volts; thereafter under the following conditions as in overcharging: In 2.6mA / cm2 of charge current density constant current charge for 10 hours; after overcharging after standing for 2 hours and at the discharge of the following conditions: a discharge current density of 0.52mA / cm2, the cutoff value was 2.75 volts. 对所述电池电压的取样时间为每30秒取样。 Said battery voltage sampling time is sampled every 30 seconds.

在所有电池的充电时观察电池电压的振荡,在充电时所述电池的电压不会增加超过5.5伏。 Observation of the battery voltage oscillation during the charging of all the batteries, during charging of the battery voltage does not increase more than 5.5 volts. 此外,过度充电后所有电池的开路电压的范围为4.2-4.5伏,因此可以在过度充电后进行放电。 Moreover, the scope of all the open-circuit voltage of the battery after the overcharge as 4.2-4.5 volts, and therefore can be discharged after the overcharge.

表2说明了电池电压振荡开始时的电荷(Q1)和过度充电后所得的放电电荷Qd。 Table 2 shows the charge of the battery voltage oscillation at the start (Q1) and the resulting discharge after charging excessive charge Qd. 作为一个实例,对采用实施例7的隔膜的电池而言,图1说明了过度充电时电压的变化,图2说明了过度充电后的放电行为。 As an example, for embodiments using a battery separator of Example 7, Figure 1 illustrates the overcharge voltage variation, Figure 2 illustrates the over-discharge behavior after charging.

比较实施例4采用比较实施例1-3的隔膜,通过与实施例8的相同的方法制备钮扣电池。 Comparative Example 4 using the separator of Example 1-3 Comparative Example, the same coin battery of Example 8 was prepared by the embodiment. 以与实施例8相同的方法对所述钮扣电池进行测试。 In the same manner as in Example 8 of the button battery to be tested.

由于隔膜的电阻大,采用比较实施例2的隔膜的电池在第一个充电/放电循环中没有显示出足够的性能。 Since the membrane resistance is large, using the battery separator of Comparative Example 2 in the first embodiment of the charge / discharge cycles did not show sufficient performance. 因此,没有对采用比较实施例2的隔膜的电池进行过度充电测试。 Therefore, no use of the battery separator Comparative Example 2 were overcharging test.

采用比较实施例1和3的隔膜的电池显示出令人满意的第一个充电/放电,因此对其进行过度充电测试。 The first uses a satisfactory charge / discharge of the battery of Example 1 and the separator of Comparative Example 3 shows, therefore its overcharge test. 但是没有观察到电池电压的振荡,电池电压的增加超过5.5伏使得不能进一步放电。 However, increasing the battery voltage oscillation, the battery voltage is not observed over 5.5 volts so that no further discharge. 图1显示了采用比较实施例1的隔膜的电池在过度充电时电压的变化。 Figure 1 shows the use of the battery separator of Comparative Example 1 at the time of overcharge voltage.

这些结果表明采用比较实施例1和3的隔膜的电池显然没有如本发明的锂离子二次电池所具有的防止过度充电的功能。 These results indicate that the use of the function of the battery of Example 1 and the separator 3 of the Comparative Example apparently did not prevent the over-charging lithium ion secondary battery of the present invention is possessed of.

实施例9采用实施例1-7的隔膜,通过与实施例8相同的方法制备钮扣电池,但是采用铜箔作为负极。 Example 9 Examples 1-7 diaphragm, by the same method as in Example 8 was prepared button battery, but the use of copper foil as a negative electrode. 采用铜箔作为负极,以0.56mA/cm2的充电电流密度对所述钮扣电池进行恒定电流充电。 Using copper foil as a negative electrode, a charging current density of 0.56mA / cm2 to the constant-current charging button batteries. 对于所有的电池而言,观察到电池电压的下降、电池电压的振荡或电池电压的升高基本上停止。 For all the batteries, the battery voltage drop is observed, the battery voltage or battery voltage oscillation increases substantially stopped.

表2说明了这个现象开始时的电荷Q2。 Table 2 shows the charge Q2 this phenomenon starts.

实施例10采用实施例1-7的隔膜,通过与实施例8相同的方法制备钮扣电池。 Example 10 Examples 1-7 use a diaphragm, by the same method as in Example 8 was prepared button battery. 在与实施例8相同的条件下,对所述钮扣电池进行过度充电测试。 In the same manner as in Example 8 under the conditions of the coin battery overcharge test. 在过度充电测试中,当Qc达到1.3mAh/cm2时,测量1kHz下的阻抗R0.5。 In the overcharge test, when Qc reached 1.3mAh / cm2, the measured impedance R0.5 1kHz under. 此外,当Qc达到5.4mAh/cm2时,测量1kHz下的阻抗R2。 Further, when the Qc reached 5.4mAh / cm2, measured at 1kHz impedance R2.

表2列出了R2/R0.5的值。 Table 2 lists the values R2 / R0.5 is.

实施例11采用实施例1-7的隔膜,通过与实施例8相同的方法制备钮扣电池。 Example 11 Examples 1-7 diaphragm, by the same method as in Example 8 was prepared button battery. 在与实施例8相同的条件下,对所述钮扣电池进行过度充电测试。 In the same manner as in Example 8 under the conditions of the coin battery overcharge test. 在过度充电测试中,当Qc达到7mAh/cm2时,停止过度充电,拆开所述电池并采用扫描电子显微镜(SEM)观察负极表面。 In the overcharge test, when Qc reach 7mAh / cm2, stop over-charging, disconnect the battery and using a scanning electron microscope (SEM) to observe the negative surface. 图3为实施例5中所用的隔膜的SEM照片,但是在所有的电池中观察到最大长度为100微米的锂颗粒的相同分布。 Example 5 Figure 3 is used in the SEM photograph of the diaphragm, but was observed in all the cells to a maximum length of 100 microns the same distribution of particles of the lithium.

对于实施例3-7的隔膜而言,在与负极接触的一侧观察到对应这些锂颗粒的表面孔,在与正极接触的一侧没有观察到表面孔。 For the membrane of Example 3-7, in the side in contact with the negative electrode was observed corresponding to these surface pores lithium particles, on the side in contact with the positive electrode was not observed in the surface pores.

实施例8-11的结果表明采用本发明的锂离子二次电池隔膜的本发明的锂离子二次电池具有如上所述的由于锂颗粒产生的防止过度充电的功能。 The results of Examples 8-11 show that the use of lithium ion secondary battery of the present invention is a lithium ion secondary battery separator of the present invention has a lithium preventing the generation of particles due to excessive charging of the function described above.

[膜制电池的评定]实施例12采用实施例8制备的具有相同面积的正极和负极以制备采用实施例5的隔膜的膜套(film-sheathed)电池。 [Evaluation of film-made cell] Example 12 using the positive electrode having the same area and the negative electrode prepared in Example 8 was prepared using the film cap to the separator of Example 5 (film-sheathed) battery. 通过隔膜连接正极和负极、置于至铝-塑料层压组件内并注射电解质溶液从而制备所述膜套电池。 Connecting positive and negative electrodes through the separator, is placed into an aluminum - plastic laminate assembly and injecting an electrolyte solution to thereby prepare the film cap battery. 用于这种膜制电池的电解质溶液通过将LiPF6溶解在组成为EC∶DEC:MEC=1∶1∶1(重量比)的混合溶剂中来制备,溶液的浓度为1M。 Electrolytic solution used in such film-made cell by dissolving LiPF6 in a composition EC:DEC: MEC = (weight ratio) mixed solvent to prepare 1:1:1, concentration of the solution is 1M. 所述膜制电池的尺寸为55mm×35mm×3.7mm。 The film-made cell size of 55mm × 35mm × 3.7mm.

采用与实施例8相同的方法对最初充电/放电进行测量时,发现膜制电池的容量为650mAh。 Using the same method as in Example 8 when the initial charging / discharging was measured and found that the film made of the battery capacity of 650mAh.

在25℃的环境温度下,以2.6mA/cm2的充电电流密度对所述膜制电池进行恒定电流充电直至Qc达到1950mAh(350%的充电百分率)来过度充电。 At ambient temperature 25 ℃, and a charging current density of 2.6mA / cm2 of the film-made constant current charging until the battery reaches Qc 1950mAh (350% of the charge percentage) to overcharge. 通常在120%的充电百分率时电池电压的升高停止,稳定在约4.5-4.6伏。 Typically battery voltage rises to stop charging when the percentage of 120%, stabilized at about 4.5-4.6 volts. 在电池电压升高基本停止的同时电池的表面温度开始上升,稳定在大约50℃,最高的电池表面温度为51℃(图4)。 Surface temperature of the battery voltage rises substantially stopped while the battery begins to rise, stabilizing at about 50 ℃, the highest surface temperature of the battery 51 ℃ (Fig. 4). 在这种过度充电时没有观察到膜制电池的膨胀。 When such over-charging system was not observed expansion of the cell membrane. 此处充电百分率是指充电所用时间对充电完全所需的时间的百分比。 Here the charge percentage is the percentage of time spent on the charging time required for charging completely.

过度充电后,以0.52mA/cm2的放电电流密度进行恒定的电流放电直至2.75伏。 After overcharging to 0.52mA / cm2 discharge current density constant current discharge until a 2.75 volt. 获得656mAh的放电电量。 Get 656mAh battery discharge.

这些结果表明,即使对于实用的电池尺寸,可以有效地获得本发明的锂离子二次电池的防止过度充电的功能。 These results indicate that, even for the practical size of the battery, can be effectively obtained lithium ion secondary battery of the present invention to prevent overcharging function.

实施例13以2.6mA/cm2的充电电流密度,对具有与实施例12中制备的膜制电池相同结构的膜制电池进行过度充电至186%的充电百分率,将所述电池进行烘箱加热测试。 Example 13 A charging current density 2.6mA / cm2, and having the same structure as in Example film-made cell membrane preparation were prepared battery 12 from overcharge to 186% of the charging percentage of said battery oven heating test. 烘箱中的升温速率为5℃/分钟,当温度达到150℃时使所述电池静置1小时。 Oven heating rate of 5 ℃ / min, when the temperature reached 150 ℃ enable the battery to stand for 1 hour. 结果,没有发生破裂或着火,尽管电池出现了膨胀。 As a result, rupture or ignition does not occur, despite the expansion of a battery.

比较实施例5采用与实施例12相同的方法制备膜制电池,不同之处在于采用比较实施例1的隔膜,在2.6mA/cm2的充电电流密度下,对其过度充电至186%的充电百分率,此后在与实施例13相同的条件下,对所述电池进行烘箱加热测试。 Comparative Example 5 Example 12 using the same film-made battery was prepared, except that Comparative Example 1 using the membrane embodiment, at 2.6mA / cm2 charging current density, overcharging percentage to 186% charge and thereafter under the same conditions as in Example 13, to the battery oven heating test. 当烘箱温度达到125℃时电池破裂并着火。 When the oven temperature reaches 125 ℃ battery rupture and fire.

实施例14制备具有与实施例12中制备的膜制电池相同结构的膜制电池。 Preparation Example 14 having the same structure of the film-made cell membranes prepared cells prepared in Example 12. 将该膜制电池进行5次过度充电循环测试,以2.6mA/cm2的充电电流密度充电至Qc为1300mAh,以0.52mA/cm2的恒定放电电流进行放电直至2.75伏。 The film was made 5 times over the battery charge cycle test to 2.6mA / cm2 charging current density to charge Qc is 1300mAh, to 0.52mA / cm2 at a constant discharge current discharged until 2.75 volts. 在所述测试中电池没有出现膨胀、破裂或着火,即使在第五次循环后放电容量仍有448mAh。 Does not appear in the test battery is expanded, rupture or fire, even after the fifth cycle discharge capacity still 448mAh.

实施例13和14以及比较实施例5的结果表明与常规的锂离子二次电池相比,本发明的锂离子二次电池对于过度充电是非常安全的。 Examples 13 and 14 and Comparative results of Example 5 show that compared with the conventional lithium ion secondary battery, a lithium ion secondary battery of the present invention for the overcharging is very safe.

实施例15制备具有与实施例12中制备的膜制电池相同结构的膜制电池,将检测放热的chalk marker(热标签)粘到所述膜制电池的表面。 Example 15 Preparation of the film made with the same structure as cell membranes prepared cells prepared in Example 12, to detect exothermic chalk marker (thermal labels) adhered to the surface of the film-made cell. 以2.6mA/cm2的充电电流对所述电池进行过度充电至Qc为900mAh。 In charging current 2.6mA / cm2 of the battery is overcharged to Qc as 900mAh. 粘附的chalk marker显示出颜色发生了变化。 Adhesion chalk marker shows the color changed.

比较实施例6制备具有与比较实施例5中制备的膜制电池相同结构的膜制电池,将检测放热的chalk marker(热标签)粘到所述膜制电池的表面。 Comparative Example 6 Preparation of Comparative Example having the same structure as the surface of film-made cell membranes prepared cells prepared in Example 5, will detect exothermic chalk marker (thermal labels) adhered to said film-made cell. 以2.6mA/cm2的充电电流对所述电池进行过度充电至Qc为900mAh。 In charging current 2.6mA / cm2 of the battery is overcharged to Qc as 900mAh. 粘附的chalk marker没有显示颜色发生变化。 Adhesion of chalk marker did not show color change.

当实施例15的电池显示出防止过度充电的功能时,将通过充电法引入所述电池的电能没有贮存在所述电池内,而以焦耳热的形式从所述系统释放出来。 When the battery of Example 15 exhibited when the function of preventing over-charging, the battery power will be introduced through the charging method is not stored in the battery, and in the form of Joule heat released from the system. 相比而言,对于比较实施例6的电池而言,所有引入所述电池的电能贮存在电池内,而没有产生热,因此chalkmarker的颜色没有发生变化。 In contrast, for the battery of Comparative Example 6, the introduction of all the electric energy stored in the battery cell, and no heat is generated, so chalkmarker color has not changed.

实施例15和比较实施例6的结果表明本发明的锂离子二次电池的优点在于可以有效地使用热敏电阻型防止过度充电的电路,而该电路不能用于常规的锂离子二次电池中。 Results of Example 15 and Comparative Example 6 show that the advantages of the present invention is a lithium ion secondary battery that can be effectively used to prevent over-charging type thermistor circuit, and the circuit can not be used in a conventional lithium ion secondary battery .

表2 Table 2

工业应用性根据本发明,可以通过将来自过度充电时在负极上生成的锂颗粒的锂涂布正极来防止锂离子二次电池的过度充电,因此提供了一种在过度充电时仍然安全的锂离子二次电池。 Industrial Applicability According to the present invention, can be obtained by applying a positive electrode from a negative electrode in lithium lithium particles produced on the lithium ion secondary battery to prevent overcharge when the overcharge, thereby providing a safety during overcharge still lithium ion secondary battery.

Classifications
International ClassificationH01M10/36, H01M10/0525, H01M10/0565, H01M10/05, H01M6/50, H01M10/42, H01M2/02, H01M10/44, H01M2/14, H01M2/16
Cooperative ClassificationH01M2200/10, H01M10/0525, H01M2/1686, H01M2/162, H01M2/1666, H01M2/022, H01M2/14, H01M10/4235, H01M2/145, H01M10/0565, H01M10/448, H01M2010/4292, H01M10/44
European ClassificationH01M2/14M, H01M2/16L, H01M10/44, H01M2/16B3, H01M2/16D, H01M2/14, H01M10/0525, H01M10/0565, H01M10/42M
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