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Publication numberCN1591931 A
Publication typeApplication
Application numberCN 200410078979
Publication date9 Mar 2005
Filing date7 Mar 2001
Priority date7 Mar 2000
Also published asCA2373904A1, CA2373904C, CN1197192C, CN1290208C, CN1372706A, DE60143873D1, EP1191622A1, EP1191622A4, EP1191622B1, US6818352, US20030003363, US20050079406, WO2001067536A1
Publication number200410078979.0, CN 1591931 A, CN 1591931A, CN 200410078979, CN-A-1591931, CN1591931 A, CN1591931A, 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 1591931 A
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, the separator and the non-aqueous 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 and coating cloth, in the total amount of the positive electrode of lithium Qp (mAh) and the amount of lithium may be coated anode Qn (mAh) of the relationship Qp> Qn, when to 0.2Qn <Ic <2Qn charging current Ic (mA), with 1 <Qc / Qn <when Qp / Qn charge Qc (mAh) start charging the battery via lithium on the negative electrode material for the positive electrode of lithium generated coating, and continued to Qc> Qp.
Claims(9)  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。 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, measured according to JIS P8117 sheet air permeability of not more than 100 seconds ( 25 ℃ immersed under A), an electrolyte solution through said sheet (A) and the impedance of the electrolyte solution alone impedance ratio of 10 or less, the impedance ratio × average thickness of not more than 200 microns.
2.权利要求1的隔膜,其中所述片材由纤维组成,组成所述片材的纤维的平均直径为所述片材(A)的平均膜厚的1/2-1/10。 The average diameter of the diaphragm according to claim 1, wherein said sheet is composed of fibers, the fibers constituting the sheet of the sheet (A) has an average thickness of 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。 3. The membrane of claim 2, wherein said sheet material (A) 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 said sheet material (A) a 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,所述多孔膜包含多孔有机聚合物膜(B),所述多孔有机聚合物膜(B)包围权利要求1-3中任一项所述片材(A)并且可被所述电解质溶液溶胀和保持所述溶液。 A porous film comprising a lithium ion secondary battery separator, the average thickness of the porous film is 10-35 microns, a basis weight of 10-25 g / m 2, said porous membrane comprising a porous organic polymer membrane (B), said porous organic polymer film (B) is surrounded claimed in any one of the sheet 1-3 (A) and the electrolyte solution can be maintained and the swelling solution.
6.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。 6. The membrane of claim 5, wherein the porous organic polymer film (B) mainly composed of polyvinylidene fluoride composition.
7.权利要求6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。 7. The membrane of claim 6, wherein the porous organic polymer film (B) by the biasing containing 92-98 mole% of vinylidene fluoride polyvinylidene fluoride copolymer composition.
8.权利要求7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。 8. The membrane of claim 7, wherein said porous organic polymer film (B) by the vinylidene fluoride, hexafluoropropylene and chlorotrifluoroethylene terpolymer composition.
9.权利要求8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/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。 9. The membrane of claim 8, wherein the copolymer composition of the terpolymer vinylidene fluoride / hexafluoropropylene / chlorotrifluoroethylene, hexafluoropropene which is 2-8% by weight, chlorine trifluoroethylene 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 separator, battery packs and charging method

本中请是申请日为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。 Please present invention is filed March 7, 2001 to create the name of Chinese patent application as "lithium ion secondary battery separator, battery packs and charging method" (national Application No. No.01801175.6, International Application Number PCT / JP01 / 01785) of the divisional application.

技术领域 Technical 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 electrical high security, low-cost lithium-ion secondary battery during overcharge, involving the lithium ion secondary battery separator used in the battery pack and is equipped with the lithium ion secondary batteries / electronic equipment and a method for charging 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 enhancements in recent years, portable electronic devices, secondary batteries with high energy density corresponding requirements put forward. 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 the secondary electrochemical cell can be applied using the (doped) and to the coating (dedoped) of carbon material, lithium as negative electrode active material, and 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 a 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, it is because it is the average output voltage 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 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 commonly referred 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。 Anhydrous secondary battery flammable aqueous electrolyte solution as an electrolyte solution, so there is a fire hazard, 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 a fire hazard, but is especially dangerous overcharging.

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)。 To prevent overcharging, using a constant current and constant voltage to the existing dry 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 protection circuits are expensive, thus increasing the cost of anhydrous 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 operation 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。 In anhydrous existing secondary batteries made various improvements such as providing safe discharge port (safety vent), PTC element and having a hot-melt function (cut-off function) of the diaphragm so 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。 But even provide such a device, according to the situation of over-charging, over-charging when security is not always able to get a reliable guarantee, in fact, dry 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。 Since from the viewpoint of safety and cost, to prevent the nonaqueous secondary battery overcharge safety measures are still insufficient, and therefore there is still a problem 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 when the protection circuit failure in a safe manner damage the battery. 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 adding a compound stable during overcharging generating gas and cause safety discharge port fast start, as described in Japanese Patent No. 3,061,756 proposes the addition of a compound at the time of overcharging polymerization, thereby blocking current, and Japanese Patent Publication No. 11-45740 Failure to review proposed adding a a compound having an endothermic effect upon overcharging; This method involves a number of additives that have been used and the 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 the simple removal of the protective circuit protection or as having a thermistor system 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 to Japanese Unexamined Patent Publication No. 6-338347, Japanese Unexamined Patent Publication No. 2000-251932, Japanese Unexamined Patent Publication No. 2000-277147, Japanese Unexamined Patent Publication No. 2000-228215 provenance 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 additives cause 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。 Some of these additives has been adopted, and contribute to improving the safety of nonaqueous secondary batteries, 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 Unexamined Patent Publication No. 2000-67917 proposes a method by using a gel - polymer electrolyte membrane to prevent over-charging technology, 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 - polymer electrolyte membrane thickness of not less than 30 microns, 40 microns or greater in order 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 membrane in most conventional nonaqueous secondary battery of 25 microns, such thickness is not widely adopted, with constantly improving battery energy density, the separator thickness 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 Unexamined Patent Publication No. 2000-123824 also proposes a gel - polymer electrolyte to prevent over-charging technology, 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 overcharging polyether oligomer, but the technique has not been widely adopted, as compared with conventional nonaqueous secondary battery, discharge characteristics of the battery is poor.

发明内容 DISCLOSURE

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 aforementioned problems in the prior art, the nonaqueous secondary battery while maintaining a practical battery characteristics allows to simplify or eliminate the 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, improved 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 can be reversibly coated and coated to make Qp> Qn, where Qp (mAh) is necessary to charge in all lithium contained in the positive de-coating, Qn (mAh) is the cause of all applied to the negative electrode of lithium necessary charge, and 3) when the range of 0.2Qn / h <Ic <2Qn / h charging current Ic (mA), in the range of 1 <Qc / Qn <Qp / Qn of electric charge Qc (mAh) of battery When charging, the battery charging by the negative electrode of lithium particles begin to generate coated on a positive electrode of lithium, 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, the battery pack includes the aforementioned lithium ion secondary battery and the thermal switch systems such as thermistors and / or 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 for the aforementioned lithium ion secondary battery is charged, the method including the adoption of a constant current method for lithium-ion secondary battery is charged, and based on at least one aspect of the following determination of the charge is completed: battery temperature increases, the battery voltage drops or battery voltage oscillations.

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 equipment, 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 still further provides a lithium ion secondary battery separator, the separator comprising having an average 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 a MacMullin number × average thickness of not more 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 comprises an average 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 an organic porous polymer film (B) retainability.

附图说明 Brief Description

图1图示了在实施例8和比较实施例6的过度充电时的电压变化。 Figure 1 illustrates the 8 and the voltage changes over charging time Example 6 Comparative Example Example.

图2图示了实施例8的过度充电后的放电行为。 Figure 2 illustrates the discharge behavior overcharge Example 8 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 overcharge on the negative 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 overcharging Example 12 Figure 4 illustrates the implementation time.

具体实施方式 DETAILED DESCRIPTION

以下将更详细地对本发明进行描述。 In greater detail below on 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 include a positive electrode, a negative electrode, the separator and the non-aqueous 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 Qp> Qn, where Qp (mAh) is necessary to cause all of the charge on the positive electrode containing lithium to be coated, Qn (mAh) is applied to all the necessary cause of lithium on the negative electrode charge, and 3 ) When the range of 0.2Qn / h <Ic <when 2Qn / h charging current Ic (mA), the range of 1 <Qc / Qn <Qp / Qn of electric charge Qc (mAh) to charge the battery through the battery so on the negative charged lithium particles begin to generate lithium coated on the positive, and continued to achieve 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 excessive charging function] when practical charging current Ic, so 0.2Qn / h <Ic <2Qn / h lithium ion secondary battery of the present invention will be charged, it will not happen in the case of over-charging in the negative coating, such deposited particles reach the vicinity of the positive electrode of lithium surface, coated on the positive electrode, this phenomenon continues until 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 cathode surface to the shallow depth of overcharging, in which the charge Qc so that 1 <Qc / Qn <Qp / Qn, then not only can guarantee overcharging lithium-ion secondary battery safety, and will reach a positive electrode of lithium particles near the surface of the coating to the cathode, so as not to complete an internal short circuit occurs between the positive and the negative, even after overcharging may discharge.

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 in the negative when generated on the positive electrode of lithium particles coated to prevent over-charging, and through continued this phenomenon to Qc> Qp to ensure that the battery during overcharge security; however, in order to ensure greater safety of the battery, preferably this phenomenon continued to 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 <this phenomenon 1:00 lithium ion secondary battery is not capable of fully charged battery, it is not preferable battery. 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, due to relate to the amount of 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 this prevented excessive order to obtain a rechargeable lithium-ion secondary battery, it must make the relationship between Qp and Qn of 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。 Prevent excessive charging function of the present invention is achieved by the use of lithium during overcharge particles are deposited onto the surface of the negative electrode obtained, these particles initially contained lithium on the positive electrode, since the amount of charge available at the time of Qp-Qn, if Qp <Qn on preventing excessive charging function principles of the present invention it 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 preferable to use the positive half of the remaining amount of lithium, this exhibit features to prevent 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 more preferable to use a shallow depth of charge, when Qc meet 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。 In this case, the positive electrode active material may be formed per unit area of the anode active material and weight to calculate the 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 battery and measure the charge / discharge is determined, wherein the three-electrode system through the use of 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。 You can use the following method to ensure that the battery of the present invention, such features prevent overcharging. 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 is removed Qp and Qn measured by the method described above in order to ensure that the relationship 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。 It can also be removed from the lithium ion secondary battery of the present invention, the positive electrode, a negative electrode and a separator, connecting the anode and cathode through the separator, and injecting an electrolyte (electrolyte solution) in order to assess the battery manufacturer. 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 has confirmed that when evaluating the use of cell 1 to meet the conditions 0.2Qn / h <Ic <2Qn / h charging current Ic for charging, when Qc in the range of 1 <Qc / Qn <Qp / Qn when the battery voltage drops can be observed, battery voltage oscillation or the battery voltage rises substantially stopped. 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 increased substantially stop the charge defined at the start of 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 increased substantially stopped or decreased according to the battery voltage, 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。 Then removed from the separator and the positive electrode of lithium ion secondary battery of the present invention, the positive electrode and the negative electrode through the separator collector (collector) is connected (ie Qn = 0), electrolyte (electrolyte solution) is injected to make the assessment battery 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 of the negative electrode collector battery 2 as the negative electrode, the battery voltage drops, the battery voltage or battery voltage oscillation rise substantially Stop at the start 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。 In this case, if the relationship Q1> Q2 (ideal is Q2 = Q1-Qn) was established, it can be observed battery voltage drops, the battery voltage or the battery voltage oscillation basically stopped rising generation will depend on the negative electrode for lithium particles, said Li originally included on the positive, and it was confirmed that the desired function to prevent overcharging.

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 tests, when it is difficult to remove the negative electrode collector may be used in place of copper foil or lithium 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。 Typically an electrolyte solution for lithium ion secondary batteries 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 to prevent overcharging, introduced by charging energy to Joule heat released in the form of external systems. 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 effect 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 the actual charge current Ic applications, it is preferable to assess battery with a smaller capacity. 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 evaluation for the button-type battery (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 be using lithium cobalt oxide as the positive electrode and lithium can be coated / coated carbon material is applied to the negative electrode of the most common types of lithium ion secondary battery to prevent overcharging of the preceding functions 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 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, all consumed by preventing the positive electrode of lithium, namely by stopping further charge to ensure the safety of over-charging, but the lithium ion secondary battery of the present invention to prevent over-charging function is characterized by over-charging lithium particles deposited on the negative electrode 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 the lithium That is, it must not be greater 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 use of lithium deposited on the negative electrode when coating particles to 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, it 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。 The present invention has the following features have based on the 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 to meet 0.2Qn / h <Ic <2Qn / h charging current Ic to charge the battery, the battery voltage drops occur, the battery voltage or the battery voltage rises oscillation range basically stopped when 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。 In this case, when the negative electrode on the resulting particle coating on the positive electrode of lithium, declining battery voltage. 电池电压的振荡表明锂颗粒的间歇涂布。 Battery voltage oscillation show 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 oscillation depends on the battery's internal resistance, 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 it 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 deposited at the negative electrode and a positive electrode coating to very fast cycle of situation is difficult to observe the battery voltage drops and battery voltage oscillations. 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 the flip circulation (turnover cycle) is fast and low internal impedance of the battery, the battery voltage phenomenon observed significant rise substantially stopped.

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 to meet 0.2Qn / h <Ic <2Qn / h charging current Ic to charge the battery, starting battery voltage 10mV or greater oscillation and continue to Qc> Qp, then charge Qc range of 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 repeat lithium particles deposited on the negative electrode and coated on a positive cycle, if sustained to Qc <Qp, the show enough to prevent over 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 to satisfy 0.2Qn / h <Ic <2Qn / h of the charging current Ic to the battery charge Qc is 2 <Qc / Qn <3 and then to satisfy 0.1Qn / h <Id <0.5Qn / h discharge When the current Id discharge, the discharge capacity Qd in the 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 the 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 to prevent overcharging work, then consider the remainder of the lithium negative electrode, the discharge capacity Qd 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 charging current Ic for charging, the battery voltage is not greater than the total of 5.5V, which 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 to an 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 material commonly used to prevent over-charging function is activated when 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 in the battery when Qc Qc = Qp meet 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 over-charging, over-charging accompanied by decomposition usually does not occur, so the battery impedance is not significantly increased.

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 satisfies Qp <Qc <1.5Qp Qc range, 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 deposited on the negative electrode for lithium particles become very thin so that they quickly reach the vicinity of the positive electrode surface, it shows a function to prevent 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。 Lithium ion secondary battery of the present invention having the above principle 1) -6) of all features, but when the charging current increases as the battery capacity is increased, due to the Joule heat of the problem, 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, it may be required to ensure that a lithium ion secondary battery of the present invention, by satisfying the above properties 1) -6) 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。 Such as to prevent excessive charging function, as expected, the lithium ion secondary battery of the present invention did not produce abnormal overcharge when decomposition of the electrolyte solution, did not cause damage to 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 damage to 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 lithium ion secondary battery of the present invention in terms of positive and negative electrodes, lithium reversibly may be used and applied to the coating of the active material and lithium ion secondary batteries generally available material that is used without any particular restrictions, as long as the 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 binder polymer and the binder holding the collecting electrode composed of the electrolyte solution. 也可以加入导电助剂以提高所述电极的导电性。 Conductive additive may 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 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 copolymer and the like; hydrocarbon polymers such as styrene - butadiene copolymer 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。 It may 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, it will have excellent oxidation resistance of the material used in the cathode, it 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, it is preferable for the positive electrode 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) 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, conductive agent and a binder polymer, it is 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 publicly known method.

[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 present invention preferably uses 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), the average film thickness of 10-35 microns, a basis weight of 6-20g / m2, air permeability (JIS P8117: 100 ml pressure air through one square inch 2.3cmHg region The time required) is not more than 100 seconds, MacMullin number of 10 or less and an average thickness × MacMullin number 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 assembled battery having a plurality of through holes, generally the ratio (curvature) and the minimum length of the film thickness of the separator and the negative electrode of the positive electrode measured along the diaphragm between the through hole 1, in When overcharge lithium on the negative electrode particles may be generated more easily reach the vicinity of the surface of the positive electrode. 因而这是优选的以表现出上述的防止过度充电的功能。 It is therefore preferred to exhibit the above features 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 thickness of less than 10 microns and a basis weight of less than 6g / m2 sheet showing more overcharge prevention function, but its strength is not enough and easily short-circuited, and therefore is not preferably used as the 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 short-circuiting the normalized 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 / m, 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 perpendicular to the sheet of piercing the middle to 50mm / min at a fixed speed the needle out of, based on the average thickness of the sheet, the open through holes in the sheet material effect on normalizing 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, the substrate sheet weight of less than 6 g / m 2 is difficult to obtain 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。 The average thickness of greater than 35 microns, based heavily than about 20 g / m 2 and permeability (JISP8117) over 100 seconds of the sheet, not only from a functional point of view to prevent overcharging is disadvantageous, but also from cell characteristics and concomitant reduction in the 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 count the number of MacMullin MacMullin not greater than 200 microns × 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 of not more 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, which is impregnated with the electrolytic solution sheet (A) alone impedance than the impedance of the electrolyte solution. 通过本发明,MacMullin数是指在25℃下测量的值。 By the present invention, MacMullin number refers to the value at 25 ℃ in measurement. 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 of greater than 35 microns, greater than 20 g / m 2 weight groups and more than 100 seconds of air permeability (JIS P8117), it is difficult to meet the MacMullin number and the number × average thickness value MacMullin conditions .

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) in terms of specific examples, there may be mentioned a sheet having a hard projection or laser film apart apertures, such as a conventional fine structure for a lithium ion secondary battery separator of polyolefin porous membrane or sheet by a variety of fibers such as a nonwoven fabric is formed; however, there is no particular limitation on the sheet (A), as long as the above conditions can 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, consisting of a sheet of fibers having an 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 smaller than the average thickness of the sheet (A) is 1/10, the curvature will increase, not only sufficient battery characteristics can not be obtained, but also the function of preventing overcharging 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) 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, a short-circuit problem 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 present invention are described below, 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 may be any conventional dry film, spun bonding, injection (water needle) method, spunlace, wet sheet process and melt-blown 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, the wet sheet is particularly preferred method, 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。 That the lithium ion secondary battery of the present invention to prevent over-charging the diaphragm structure (texture) are closely related, and it is not particularly relevant to the material sheet (A) of. 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 sufficient resistance to oxidation and reductive composition suitable for use on. 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。 They 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) only needs to 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 more.

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 yet may be swollen with an electrolytic solution retention 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 slightly inferior to the diaphragm by a single sheet (A) formed on the function (since it may prevent the deposition of lithium on the negative electrode particles reach the vicinity of the surface of the positive electrode during overcharge ), but as long as the above conditions are satisfied, it can still guarantee overcharging lithium ion secondary battery 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 retaining the electrolyte solution is improved and stronger inhibitory short, and therefore it is prepared for the cell membrane is effective to meet stringent leakage on solution Conditions apply either to fold flat membrane structures such as flat-shaped battery cells to meet the stringent conditions for the short-circuit.

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 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 more normalized breakdown strength of 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 thickness of greater than 35 microns and greater than 25 g / m 2 base weight, not only for preventing the excessive charging is detrimental and results in reduced battery characteristics. 具体而言,有时低温特性是不需要的。 In particular, low-temperature characteristics are sometimes required. 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 × MacMullin porous membrane of this type 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, and therefore porous organic polymer film (B) can be the electrolyte solution is only 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 preferred range of the molecular weight of the PVdF copolymer is 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 of vinylidene fluoride polymerization ratio range for 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 of more than 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 the mole fraction of VdF is less than 92%, the crystallinity of the polymer will be too low, which may 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 a terpolymer made VdF, HFP and CTFE composition. 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 HFP (a) a copolymerization ratio of less than 2% by weight, the use of the degree of swelling of the aqueous electrolyte solution will not meet the requirements decrease occurs. 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 it exceeds 8% by weight, the elasticity of the film is not sufficiently reduced so as to keep a large amount of electrolyte solution, and when the heat resistance of the electrolyte solution holding there does not meet the requirements to be 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 effects will be insufficient, 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 the added amount is greater than 6% by weight, the use of the degree of swelling of the electrolyte solution does not appear to meet the requirements will be 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 a mixture 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), the porous film may also contain the porous inorganic 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 in the suppression of the film without sacrificing the premise ionic conductivity. 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。 As for the 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 prepared by a sheet (A) impregnating and coating used to form a porous organic polymer film (B), and then the solvent was removed to obtain a porous film. 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 producing a porous membrane.

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)进行浸渍并涂布,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 the porous organic polymer film is formed (B) the polymer used, the polymer was dissolved and the solvent compatible with water, phase separation agent (gelling agent or pore forming agent) were mixed together and dissolution, the sheet (A) was impregnated with the resulting coating solution (dope solution) and applied, and the resulting film was immersed in an organic polymer film (B) aqueous coagulation bath to coagulate to form a porous polymeric material, 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渍并涂布,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, wherein the porous organic polymer film is formed (B) the polymer used, the polymer is dissolved in a volatile solvent and mixed with the plasticizer were dissolved, the sheet (A) coated with the resulting fabric was coated and impregnated, 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) a volatile polymer 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), 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 organic polymer forming a porous film (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。 A second aspect of the present invention is superior to the first form of the diaphragm place is immersed in an electrolyte solution and maintained. 可以通过浸渍电解质溶液的量来评定电解质溶液的浸渍。 It can be assessed by the amount of impregnated electrolyte solution impregnating the electrolytic solution. 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 electrolyte solution impregnating an electrolyte solution impregnated dry weight percentage represented by the diaphragm. 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 diaphragm of the electrolyte solution retention by centrifugation using aqueous electrolyte membrane impregnated with a solution to be assessed, where centrifugal force 1400 × g (acceleration of gravity), centrifuged for 20 minutes to remove the non-aqueous electrolyte solution kept weak. 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 by the weight of the membrane after centrifugation weight percent by weight of the centrifugal separator prior to represent. 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 retention of the electrolyte solution is 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。 Considering the workability in the preparation of the battery, 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 safety limit stress. 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 safety limit stress level marked elastic limit strength and can handle tensile force of the film, the larger values indicate easier to handle and have higher productivity.

所述安全限应力通常由拉伸测试进行确定。 The safety limit is generally determined by the tensile stress test. 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, the membrane was cut out pieces of 1cm × 3cm, be obtained by the tensile test tensile stretching rate 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 separator of the present invention is preferably 150 ℃ or more, 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) evaluate the thermal deformation 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。 Methods of assessment by TMA heat distortion temperature can be carried out as follows: cut out from the membrane 4mm wide strips, 0.01N load applied thereto at a rate of 10 ℃ / min temperature rises, when there at least 2% of the change in length Temperature (elongation) is determined during 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。 [Aqueous 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。 As specific examples of non-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 anhydrous solvents may be used alone or in combination of two or more kinds of use. 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 selected PC, EC, γ-BL, DMC, DEC, MEC, and DME in any one or more solvent.

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)。 Preferably in the range of the concentration of dissolved lithium salt is 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 be prepared using a lithium ion secondary battery of any publicly known method.

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 the separator through the anode and cathode coupled within the housing, which is then injected into an electrolyte 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 the 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渍。 It may be coupled to an electrode disposed in the housing before impregnated with an electrolyte solution.

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 - film assembly consisting of a plastic layer, 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, the membrane is preferably a porous membrane the second mode. 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。 Adhesive membrane and electrode is mainly done by thermo-compression bonding, which may be implemented in the absence of an electrolyte-containing 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, the cell may be prepared in the next step without thermocompression bonding.

[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, coin or sheet-like shape.

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 cylinder, 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 over-charging, charging method enables 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 can be expressed as Joule heat (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 display features to prevent overcharging the battery voltage is substantially constant, Ic is the main factor 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 internal battery temperature rise caused could endanger batteries, such as burning. 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。 Therefore, 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 viewpoint of, 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。 It can also be used to install radiant panel on 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。 Due to the foregoing 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 battery, the battery needs to membrane system stringent conditions, from this point of view, the lithium ion secondary battery of the present invention preferably take the form of cell membrane system. 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。 In addition, although usually mounted discharge port security in the conventional lithium ion secondary batteries, but because of the over-charging lithium ion secondary battery of the present invention, gas generation is suppressed, can not provide security in the premise of full discharge port ensure the safety of over-charging. 但是,当然如果存在安全排口,安全性将得到进一步提高。 But, of course, if there is a security 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。 Since the Joule heat problems, depending on the charging current Ic, safety lithium ion secondary battery of the present invention over charging in some cases may not be guaranteed. 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, the high charge current (rate), lithium ion secondary battery of the present invention is not preferable to prevent 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 publicly known various additives for improving the safety during overcharging 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 is based on the use of publicly known additives principle 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 ensure the safety of over-charging, even at high charging current (rate) lower as 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] The battery pack of the present invention is equipped with a lithium-ion secondary battery and thermal sensors (thermal sensor) 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 prevents overcharging 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 heat of the over-charging lithium ion secondary battery of the present invention, and thus from a security point of view, in the battery pack assembly thermal sensors (thermal sensor) or thermal switch (thermistor and / or PTC ) is valid.

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 sensor) 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 fitted with a protective circuit. 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 charging method of the present invention includes a method by constant current lithium ion secondary battery of the present invention will be charged, according to at least one of the following the completion of the charge to judge: battery temperature, the battery voltage drops or battery voltage oscillations.

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。 A lithium ion secondary battery of the present invention is characterized in that not only ensure the safety of over-charging by the above charging over 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 temperature rise of the battery, the battery voltage drop or battery voltage oscillation is detected to 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 temperature of the battery rises, the battery voltage drops 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 aforementioned method, can be employed any conventional method, such as method of charging a 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。 [Electrical / electronic equipment] The present invention also provides an electrical assembly of the present invention, a lithium ion secondary battery or a lithium ion secondary battery pack / electronic equipment.

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。 Lithium ion secondary battery of the present invention or a lithium ion secondary battery pack can be applied to various portable electronic devices such as cellular phones or laptop computers. 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 to conventional constant-current / constant-voltage charging method, using the above charging method 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。 The following will further detail the present invention will be explained by 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。 [Diaphragm] Example 1 fineness 0.22dtex adhesive polyethylene terephthalate (PET) staple fiber (average fiber diameter: about 4.5 microns) and the fineness of the orientation and crystalline 0.33dtex PET staple fibers (average fiber diameter: about 5.5 microns) to be blended in a weight ratio of 4/6, a basis weight of 12g / m2 by a wet film-forming method and sheet by calender roll 200 ℃ to obtain a nonwoven fabric sheet. 所得片材的性质如下。 The following properties of the resulting sheet.

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 puncture strength: 5.0 g / m (90 g), MacMullin Number: 5.0 (MacMullin number value = 90 m × film thickness).

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 with a needle implemented in polypropylene (PP) uniform open pore membrane (CELGARD TM2400, Celgard Co. product) on a number of holes 2 microns in diameter. 所得片材的性质如下。 The following properties of the resulting sheet.

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 binder PET staple fibers (average fiber diameter: about 11 m) and the fineness of 0.55dtex the orientation and crystallinity of PET staple fibers (average fiber diameter: about 7 microns) to 5 w / 5 ratio in blending, a basis weight of 12g / m2 by a wet film-forming method and sheet by calender roll 160 ℃ to obtain a nonwoven fabric sheet. 所得片材的性质如下。 The following properties of the resulting sheet.

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 puncture 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。 The following properties of the resulting porous film.

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 puncture 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 dry plate method, using a fineness of between 0.9dtex crystalline aramid staple 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 ℃ The nonwoven fabric sheet. 所得片材的性质如下。 The following properties of the resulting sheet.

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 puncture strength: 5.6 g / m (95 g), MacMullin Number: 5.8 (MacMullin Number Value = 98.6 microns × film thickness).

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, thereby preparing 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。 The following properties of the resulting porous film.

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 puncture 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 binder 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 microns) to 4 / 6 wt basis weight 11g / m2 film blended ratio, and is formed by a wet method by sheet roll 200 ℃ calender to obtain a nonwoven fabric sheet. 所得片材的性质如下。 The following properties of the resulting sheet.

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 puncture strength: 5.6 g / m (95 g), MacMullin Number: 5.8 (MacMullin number value = 99 m × film thickness).

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。 Using the same coating solution as in Example 3 prepared in this nonwoven fabric sheet was impregnated and coated, the resulting film 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。 The following properties of the resulting porous film.

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 puncture strength: 5.0 g / m (120 g), MacMullin Number: 5.4 (MacMullin number value = 130 × film thickness m), 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) was dissolved in the composition containing N, N- dimethylacetamide (DMAc) and the 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 formed in Example 1 embodiment, 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。 The following properties of the resulting porous film.

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x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 puncture strength: 6.3 g / m (151 g), MacMullin Number: 6.5 (MacMullin number x film thickness value = 156 microns), 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 binder 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 were blended, a basis weight of 12g / m2 by a wet film-forming method and sheet by calender roll 130 ℃ to obtain a nonwoven fabric sheet. 所得片材的性质如下。 The following properties of the resulting sheet.

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 puncture 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。 Using the same coating solution as in Example 3 prepared in this nonwoven fabric sheet was impregnated and coated, the resulting film 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。 The following properties of the resulting porous film.

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 puncture 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 of the diaphragm 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)。 The separator used in Comparative Example 1 Example polypropylene (PP) fine porous film (CELGARD TM2400, CelgardCo. Product). 膜的性质如下。 The nature of the film is 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 between 0.9dtex crystalline aromatic polyamide staple fibers (average fiber diameter: about 10 microns) and inter-aramid fibril (fibrit) (synthetic 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 320 ℃ calender roll to obtain a paper-like sheet. 得到的片材的性质如下。 Properties of the resulting sheet are 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 PET using an 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 non-woven fabric by calender rolls 130 ℃ 50 micron membrane press forming. 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 puncture 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 prepared in this nonwoven fabric sheet was impregnated and coated, the resulting film 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。 The following properties of the resulting porous film.

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 m, 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 a positive electrode paste (NMP) to prepare a solution, comprising 89.5 parts by weight of lithium cobaltate powder ( LiCoO2, Nippon ChemicalIndustrial Co., Ltd. of product), 4.5 parts by weight of acetylene black and 6 parts by weight (dry weight) of 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 paste was applied to 20 m thick aluminum foil and drying the resultant, 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 anode from the cathode weight of Qp is 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。 [Negative] NMP solution was prepared using negative electrode paste having 6% by weight of PVdF, comprising 87 parts by weight of negative electrode active material as an intermediate phase carbon microbeads (MCMB, Osaka GasChemical Co., Ltd. Product) powder, 3 parts by weight acetylene black and 10 parts by weight (dry weight) of 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 resulting paste was applied on to 18 micron thick copper foil and dried, 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 three electrode cell, the anode can be coated on the amount of lithium 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 prepared] of the positive electrode and the negative electrode punched into a ring having a diameter of 14 mm, the embodiment of the membrane prepared in Examples 1-7 punched into 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)浸渍并铸封在电池壳体内。 The positive electrode and the negative electrode are each connected by a diaphragm, with an electrolyte (electrolytic solution) is impregnated and sealed in a battery casing cast. 所用的电解质溶液为1M的LiPF6 EC/DEC(1/1重量比)。 The electrolytic solution used was a 1M LiPF6 EC / DEC (1/1 weight ratio). 电池壳尺寸为CR2032。 Battery case size is 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 of overcharging] by the following preparation of various embodiments of a button battery overcharging assessment: measured 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 up to 4.2 volts, the discharge current density of 0.52mA / cm2 at a constant current discharge, the cut-off value of 2.75 volts; thereafter under the following conditions embodiments overcharging: In 2.6mA / cm2 of constant current charging current density charge for 10 hours; after overcharging after standing for 2 hours under the following conditions embodiments discharge: discharge current density of 0.52mA / cm2, the cut-off value of 2.75 volts. 对所述电池电压的取样时间为每30秒取样。 Said battery voltage is sampled every sampling time 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 the open circuit voltage of all battery after overcharge of 4.2-4.5 V, it can be discharged after overcharging.

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 when oscillation started (Q1) and overcharge obtained after the discharge 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, the implementation of the use of cell membrane of Example 7, Figure 1 illustrates the excessive charging voltage changes, Figure 2 illustrates the discharge behavior after overcharge.

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 A membrane of Comparative Example Example 1-3, the same coin battery prepared as described by Example 8. 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 coin cell testing.

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 cycle 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。 Accordingly, no 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 diaphragm 3 Comparative Examples show, so be overcharging 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 a battery separator of Comparative Example Example 1 at 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 functional 1 and battery separator of Comparative Example 3 apparently did not prevent over-charging lithium ion secondary battery of the present invention has a.

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 Example 1-7 diaphragm embodiment, by the same method as in Example 8 was prepared button battery, but using the copper foil as the 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 the copper foil as the 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 illustrates this phenomenon of charge at the start of Q2.

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 Example 1-7 using the membrane embodiment, by the same method as in Example 8 was prepared coin 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 conditions of the coin battery from overcharging 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, measured impedance under R0.5 1kHz. 此外,当Qc达到5.4mAh/cm2时,测量1kHz下的阻抗R2。 In addition, when Qc reached 5.4mAh / cm2, measured at 1kHz impedance R2.

表2列出了R2/R0.5的值。 Table 2 lists the value of R2 / R0.5 of.

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 Example 1-7 using the membrane embodiment, by the same method as in Example 8 was prepared coin 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 conditions of the coin battery from overcharging 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, open the battery and using scanning electron microscopy (SEM) to observe the negative electrode 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 FIG. 3 is used in the SEM photograph of the separator, 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 separator of Example 3-7, in the negative electrode side in contact with the surface pores observed corresponding lithium particles, on the side in contact with the cathode surface pores were not observed.

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 showed that lithium ion secondary battery of the present invention, a lithium ion secondary battery separator of the present invention has a lithium particles produced by preventing excessive charging 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 to prepare a membrane using membrane units of Example 5 (film-sheathed) batteries. 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。 Positive and negative connections through the septum and placed into an aluminum - plastic laminate assembly and injecting an electrolyte solution thereby preparing the film sets of batteries. 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。 Electrolyte solution for such a film prepared by cell LiPF6 dissolved in a composition EC:DEC:MEC = (weight ratio) mixed solvent prepared 1:1:1, concentration of the solution is 1M. 所述膜制电池的尺寸为55mm×35mm×3.7mm。 The membrane system 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 during the initial charge / discharge measurements, found that the film made the battery capacity is 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 an ambient temperature of 25 ℃, a charging current density of 2.6mA / cm2 of the membrane prepared constant current charging until the battery reaches Qc 1950mAh (350% 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 stops at 120% charge percentage stabilized at around 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 ℃ (Figure 4). 在这种过度充电时没有观察到膜制电池的膨胀。 When this 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 charges in time required for fully charged.

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 the overcharging to 0.52mA / cm2 current density discharge constant current discharge until 2.75 volts. 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 show that even for a practical battery size, can be effectively obtained lithium ion secondary battery of the present invention to prevent over-charging 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 of 2.6mA / cm2, and having the same structure as in Example membranes prepared cell membrane preparation were prepared battery 12 from overcharging percentage to 186% of the charge, the 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 of 150 ℃ makes the battery 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 emergence of battery swelling.

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 was prepared in the same manner membrane system battery, except that in Example 1 using the separator of Comparative Example, at 2.6mA / cm2 charging current density, overcharge to 186% of its charge percentage and thereafter under the same conditions as described in Example 13, the battery of the 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 has the same structure prepared cell membrane prepared cell membrane 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 is 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 cell 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 conventional lithium ion secondary batteries, lithium ion secondary battery of the present invention for 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 was prepared having the same structure as the membrane system manufactured battery cell membrane prepared in Example 12, to detect exothermic chalk marker (thermal labels) adhered to the surface of the cell membrane system. 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 overcharge to Qc is 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 Comparative Example was prepared with a surface having the same structure prepared cell membrane prepared cell membrane prepared in Example 5, the detected exothermic chalk marker (thermal labels) adhered to the membrane cell system. 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 overcharge to Qc is 900mAh. 粘附的chalk marker没有显示颜色发生变化。 Adhesion of chalk marker did not show color changes.

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 overcharging, the battery power is 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 battery power stored in the battery, without generating heat, and therefore does not change color chalkmarker.

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。 And the results of Example 15 Comparative Example 6 shows that the advantages of lithium-ion secondary battery of the present invention is that it can effectively prevent the excessive use of thermistor type charging 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 coating the positive electrode from a lithium negative electrode of lithium particles produced lithium ion secondary battery to prevent over-charging over-charging, thus providing a safety when overcharge still Lithium ion secondary battery.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
CN103155220A *21 Oct 201112 Jun 2013帝人株式会社Nonaqueous secondary battery separator and nonaqueous secondary battery
CN103155220B *21 Oct 201120 Jan 2016帝人株式会社非水系二次电池用隔膜及非水系二次电池
CN103931021A *9 Nov 201216 Jul 2014托普泰克Hns株式会社PET non-woven fabric for separation membrane of secondary batteries and separation membrane for secondary batteries comprising same
Classifications
International ClassificationH01M10/0565, H01M10/0525, H01M10/36, H01M10/05, H01M10/42, H01M2/16, H01M2/02, H01M6/50, H01M10/44, H01M2/14
Cooperative ClassificationH01M2/14, H01M2/145, H01M2/1666, H01M2/162, H01M10/0565, H01M2200/10, H01M10/448, H01M2/1686, H01M10/4235, H01M10/44, H01M2/022, H01M2010/4292, H01M10/0525
European ClassificationH01M2/16L, H01M2/14M, H01M2/16B3, H01M10/44, H01M2/16D, H01M2/14, H01M10/0525, H01M10/0565, H01M10/42M
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