CA2115387A1 - Electrochemical cell - Google Patents
Electrochemical cellInfo
- Publication number
- CA2115387A1 CA2115387A1 CA002115387A CA2115387A CA2115387A1 CA 2115387 A1 CA2115387 A1 CA 2115387A1 CA 002115387 A CA002115387 A CA 002115387A CA 2115387 A CA2115387 A CA 2115387A CA 2115387 A1 CA2115387 A1 CA 2115387A1
- Authority
- CA
- Canada
- Prior art keywords
- compound
- spinel
- cathode
- lithium
- cell according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/581—Chalcogenides or intercalation compounds thereof
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49108—Electric battery cell making
Abstract
ABSTRACT
An electrochemical cell comprises as an anode, a lithium transition metal oxide or sulphide compound which has a [B2]X4n-spinel-type framework structure of an A[B2]X4 spinel wherein A and B are metal cations selected from Li, Ti, V, Mn, Fe and Co, X is oxygen or sulphur, and n- refers to the overall charge of the structural unit [B2]X4 of the framework structure. The transition metal cation in the fully discharged state has a mean oxidation state greater than +3 for Ti, +3 for V, +3,5 for Mn, +2 for Fe and +2 for Co. The cell includes as a cathode, a lithium metal oxide or sulphide compound. An electrically insulative lithium containing liquid or polymeric electronically conductive electrolyte is provided between the anode and the cathode.
An electrochemical cell comprises as an anode, a lithium transition metal oxide or sulphide compound which has a [B2]X4n-spinel-type framework structure of an A[B2]X4 spinel wherein A and B are metal cations selected from Li, Ti, V, Mn, Fe and Co, X is oxygen or sulphur, and n- refers to the overall charge of the structural unit [B2]X4 of the framework structure. The transition metal cation in the fully discharged state has a mean oxidation state greater than +3 for Ti, +3 for V, +3,5 for Mn, +2 for Fe and +2 for Co. The cell includes as a cathode, a lithium metal oxide or sulphide compound. An electrically insulative lithium containing liquid or polymeric electronically conductive electrolyte is provided between the anode and the cathode.
Description
::
` 2 ~ :~
211~387 `~
ELECTROCHEMICAL CELL
THIS INVENTION relates to an electrochemical cell. :
-According to the invention, there is provided an electrochemical cell, which comprises as at least part of an anode, a lithium transition metal oxide or sulphide compound which has a [B2]X4n- spinel-type framework structure of an A[B2]X4 spinel wherein A and B are metal cations selected from Li, Ti, V, Mn, Fe and Co, X is oxygen (O) or sulphur (S), and n- refers to the overall charge of the ~:.
structural unit [B2]X4 of the framework structure, and the transition metal cation of which in its fully discharged state has a mean oxidation state greater than +3 for Ti, +3 for V, +3,5 for Mn, +2 for Fe and +2 for Co;
;.
as at least part of a cathode, a lithium metal oxide or -sulphide compound; and an electrically insulative lithium containing liquid or polymeric electronically conductive electrolyte between the anode ~ ~-and the cathode, such that, on discharging the cell, lithium ions ~`-` 2~1~387 are extracted from the spinel-type framework structure of the anode, with the oxidation state of the metal ions of the anode thereby increasing, while a concomitant insertion of lithium ions into the compound of the cathode takes place, with the oxidation state of the metal ions of the cathode decreasing correspondingly.
The compounds of the anode and cathode may, in particular, be lithium metal oxide compounds.
While the cell can be a primary cell, it is envisaged that it may, in particular, be a rechargeable or secondary cell in which the reverse reactions to those set out above, take place during charging of the cell.
Thus, spinel compounds have structures that can be represented by the general formula A[B2] X4 given hereinbefore, and in which the X atoms are ideally arranged in a cubic-close-packed fashion to form a negatively charged anion array comprised of face-sharing and edge-sharing X tetrahedra and octahedra. In the formula A~B2] X4, the A cations and B cations occupy tetrahedral and octahedral sites respectively. In the ideal spinel structure, with the origin of the unit cell at the centre (3m), the close-packed anions are located at the 32e positions of the space group Fd3m. Each unit cell contains 64 tetrahedral interstices situated at three crystallographically non-equivalent positions 8a, 8b and 48f, and 32 octahedral interstices situated at the crystallographically non-equivalent positions 16c and 16d.
3 21~387 ,t In the A[B2]X4 spinel, the A cations reside in ~he 8a tetrahedral interstices and the B cations in the 16d octahedral interstices.
There are thus 56 empty tetrahedral and 16 empty octahedral sites ~, per cubic unit cell.
'I
The framework structure of the lithium metal oxide compound of the anode thus has, as its basic structural unit, a unit of the formula [B2] X4~ as hereinbefore described.
In the anode of the cell of the present invention, therefore, the B cations of the [B2]X4~ host framework structure may be regarded as being located at the 16d octahedral positions, and the X
anions as being located at the 32e positions of the spinel structure. The tetrahedra defined by the 8a, 8b and 48f ` positions and the octahedra defined by the 16c positions of the spinel structure thus form the interstitial space of the [B2] X4 framework structure for the diffusion of mobile Li+ cations.
The B cations of the framework structure may consist of one cationic type, or more than one cationic type of identical or mixed valence to provide various [B2]X4~ framework structures, the overall charge of which can vary over a wide range.
Spinel compounds having the [B2] X4~ framework structure may also be characterized by crystallographic space groups other than the prototypic cubic space group Fd3m, and may therefore not have the ideal cubic-close-packed structures hereinbefore described. For example, in Lil+jc[Mn2] 04 compounds with O~x~1, ie compounds in .~, .~i . . . .
`~
211 ~ 3~7 s which A is Li, and B is Mn, the spinel structure is distorted, as a result of the Jahn-Teller Mn3+ octahedral site ions, to I tetragonal symmetry, and the compound is characterized by the !;i tetragonal space groups F41/ddm, or, alternatively, I4l/amd in which the tetrahedral and octahedral site nomenclature differs from that as de~ined by the space group Fd3m.
Furthermore, the anode need not necessarily be a stoichiometric spinel compound, but can instead be a defect spinel. Defect spinels are well known in the large family of spinel compounds ~ 10 and can have vacancies on the A sites, or on the B sites, or on i both the A sites and B sites. For example, compounds can be ~ synthesized in which defects are created by varying the quantity !~ of B cations in the framework structure such that additional Li+
cations can enter and.leave the framework. .I.n these instances additional Li+ cations can partially occupy the 16d octahedral sites normally occupied by the B-type cations. Under such ~ circumstances these partially occupied octahedra can be ;~ considered to form part of the interstitial space. Conversely, ~: compounds can also be synthesi~ed, in which part of the ~ . 20 interstitial space defined by the 8a, 8b and 48f tetrahedral and 1 16c octahedral interstices of the spinel structure can be occupied by B-type cations, thereby rendering these particular sites at least partially inaccessible to the mobile Li cations.
The [B2] X4~ framework structure can contain in certain instances a minor proportion, typically less than 10 atomic percent, of cations other than the mobile Li-type cations, or the A and B-type cations, within the framework structure or within the 2 ~ 8 7 interstitial spaces of the framework structure, and that could serve to stabilize the structure. For example, doped spinels of stoichiometry Lil+5Mn2,~04 where O~sO,l, for example, Li~03Mnl9704 in which ~=0,03, and LiM~2Mn2s04 where M=Mg or Zn and O~sO,05, for 3 5 example, LiMgOO25Mnl9504, are more stable to cycling than the stoichiometric spinel LiMn204.
The compound of the anode may be a stoichiometric spinel selected from the group comprising Li4Mn5012, which can be written as (Li)sa[Lio33Mnl67]l6do4 in ideal spinel notation; Li4Ti5o12, which can be written as (Li)ga[Lio33Ti167]16dO4 in ideal spinel notation; LiTi2o4 which can be written as (Li)8a[Ti2]16d4 in ideal spinel notation;
¦~ LiV2o4, which can be written as (Li)8a[V2]16dO4 in ideal spinel notation; and LiFe508, which can be written as (Fe)8a[Fe15LiO,5]16d4 in ideal spinel notation.
Instead, the compound of the anode may be a defect spinel selected from the group comprising Li2Mn409, which can be written as (LiO,89Cb,ll)8a[Mnl~78~0~22]l6do4 in spinel notation; and Li2Ti307, which can be written as (Lio8900~5)8a[Ti~7~Lio29]~6do4 in spinel notation. In defect spinels, the distribution of Li+ on the A and B sites can vary from compound to compound.
Instead, the compound of the anode may have a spinel-type structure, which can be a stoichiometric or defect spinel, with a mixture of transition metal cations such as a lithium-iron-titanium oxide in which the lithium and iron cations ~i ~ 211~387 are located on the A-sites, and lithium, iron and titanium cations on the B-sites.
In a preferred embodiment of the invention, the transition metal cations, Ti, V, Mn, Fe and Co, reside predominantly or completely on the B-sites of the spinel structure, while the Li cations reside predominantly or completely on the A-sites of the .:
structure.
~ ',, .
The lithium metal oxide compound of the cathode may also have a spinel-type framework structure. Thus, the framework structure of the lithium metal oxide compound of the cathode may then also have, as its basic structural unit, a unit of the formula [B2]X4n-of an A[B2]X4 spinel, as hereinbefore described, with the transition metal cations of the anode being more electropositive than those of the cathode.
~: .
In the compound of the cathode, A and B may be a metal cation of one type, or a mixture of different metal cations. The compound of the cathode may be a stoichiometric or defect spinel compound, as hereinbefore described.
: .
When the compound of the cathode has a spinel-type structure, it may be selected from the group having as its B-type cations hi, Mn, Co or Ni, or mixtures thereof, such as Li~Mn2O4 where O~x~1 and Li~Co2O4 where O~xs2, optionally doped with additional metal ~; cations to stabilize the structure as hereinbefore described.
:~
:
~i 21~387 Instead, the compound of the cathode may have another structure type, for example a layered type structure such as that found within a system defined by a formula Li~Col~NiyO2 where Osysl and ~ O~xsl.
¦ 5 In general, the anode compound will be selected from those spinel compounds that offer a relatively low voltage vs pure lithium, typically those that offer 3V or less, while the cathode compound will be selected from those spinel compounds that offer a relatively high voltage vs pure lithium, typically those that offer between 4,5V and 3V. For example, a Li/Li4+XTisOl2 cell ~ delivers on discharge at lOO~A/cm2 (for O<x~1) an average voltage 3 of approximately 1,5V, while a Li/Li~Mn204 cell delivers on discharge at lOO~A/cm2 (for O<x~1) an average voltage of approximately 4V. Therefore, a cell in accordance with the invention can have Li4+~Ti50l2 as an anode and Li~Mn204 as a cathode, : ::
and will deliver approximately 2,5V on discharge and which is approximately twice the voltage of a nickel-cadmium cell. In another example, a Li/Li2Mn409 cell delivers a voltage of ~ approximately 2,8V over most of the discharge. Thus, a cell in :
accordance with the invention can have a Li2+~Mn409 anode and Li~Mn204 as cathode, and delivers approximately 1,2V on discharge, which is the typical voltage of a nickel-cadmium cell. It is convenient to load such cells in a discharged state, ie with the following configurations:
Li4Ti50~2/Electrolyte/LiMn204 .... (1) Li2Mn409/Electrolyte/LiMn204 ..... (2) . ,~ " . . . ~ - -. ~'".. '' ' .. ' ' ' - ~ ' ' ~ ' . -~,,""
Although it is convenient to load such cells in a discharged state, the cells may also be loaded in the charged state, if so desired. In this respect, the anodes of the invention have lithiated spinel structures and delithiated spinel structures that have the [B2]X4 spinel framework as defined hereinbefore. - -~: ' In (1), Li+ ions are extracted from Li[Mn2]04 during charge with a concomitant oxidation of the manganese ions from an average :~
valence of 3,5 to higher values, and inserted into the Li4Ti50l2 ~ :-electrode structure with a concomitant reduction of the titanium cations from the average valence state of +4 to lower values.
During this process Li~ ions are shuttled between the oxide structures without the formation of any metallic lithium, the cell voltage being derived from changes in the oxidation state of the transition metal cations in the -anode and cathode structures.
The electrolyte may be a room temperature electrolyte such as LiCl04, LiBF4, or LiPF6 dissolved in an appropriate organic salt such as propylene carbonate, ethylene carbonate, dimethyl carbonate, dimethoxyethane, or appropriate mixtures thereof.
Instead, however, it may be any appropriate polymeric electrolyte such as polyethylene oxide (PE0) - LiCl04, PE0 - LiSo3CF3 and PE0 - LiN(CF3So2) 2~ that operates at room temperature or at elevated temperature, eg at about 120C.
~ 211~387 The invention will now be described by way of non-limlting examples, and with reference to the accompanying drawings in which:
FIGURE l shows powder X-ray diffraction patterns of compounds suitable for use as anode materials in rechargeable electrochemical cells according to the invention; :~
FIGURE 2 shows powder X-ray diffraction patterns of compounds suitable for use as cathode materials in rechargeable electrochemical cells according to the invention; ;;
FIGURE 3 shows a plot of voltage vs capacity for a known Li/Li2Mn4Og cell;
FIGURE 4 shows a plot of voltage vs capacity for a known Li/Li4Mn5O12 cell; `
FIGURE 5 shows a plot of voltage vs capacity for a known 15 Li/Li4Ti5OI2 cell;
FIGURE 6 shows a plot of voltage vs capacity for a known Li/LiFesO8 cell;
: FIGURE 7 shows a plot of voltage vs capacity for a ; ;
Li/Li-Fe-Ti oxide cell;
FIGURE 8 shows a plot of voltage vs capacity for a known Li/LiMn2O4 cell;
FIGURE 9 shows a plot of voltage vs capacity for a known Li/Li~03Mnl~O4 cell;
FIGURE lO shows a plot of voltage vs capacity for a known : :~
25 Li/LiCoO2 cell;
FIGURE ll shows a plot of voltage vs capacity for the cell of Example l and which is in accordance with the invention;
~?~
~ 2~5387 FIGURE 12 shows a plot of voltage vs capacity for the cell of Example 2 and which is in accordance with the invention; -:
FIGURE 13 shows a plot of voltage vs capacity for the cell of Example 3 and which is in accordance with the invention; -~`
.~
FIGURE 14 shows a plot of voltage vs capacity for the cell of Example 4 and which is in accordance with the invention;
FIGURE 15 shows plots of voltage vs capacity for the cells of Examples 5 and 6 and which are in accordance with the invention; and FIGURE 16 shows a cyclic voltammogram of the Li/Li-Fe-Ti oxide spinel cell of Example 7.
.
The following stoichiometric spinel and defect spinel compounds were selected for use as anode materials in the examples following hereinafter~
a) Li2Mn4Og b) Li4MnsOl2 c ) Li4Ti5OI2 d) LiFe5O8 e) Li-Fe-Ti oxide spinel in which Li:Fe:Ti=2:2:1 Powder X-ray diffraction patterns of these compounds are given in Figure la-e respectively.
The following spinel and non-spinel compounds were selected for use as cathode materials in the examples following hereinafter:
a) LiMn2O~ (spinel-type structure) b) Lil03Mnl g704 (spinel-type structure) c) LiCoO2 (layered-type structure) `' 12 2~ 387 Powder X-ray diffraction patterns of these compounds are given in Figure 2a-c respectively.
In view thereof that a Li/Li2Mn4Og cell delivers on discharge 150mAh/g at an average voltage of approximately 2,8V, as indicated in Figure 3, and a Li/LiMn2O4 cell delivers on discharge 120mAh/g at an average voltage of approximately 3,8V, as indicated in Figure 8, a cell in accordance with the invention a n d h a v i n g t h e c o n f i g u r a t i o n Li2Mn4Og(anode)/Electrolyte/LiMn2O4(cathode) (2) was constructed.
The LiMn2O4 spinel compound of the cathode was synthesized by reaction oE LiOH and ~-MnO2 (chemically-prepared manganese dioxide, CMD) firstly at 450C for 48 hours and thereafter at 750C for 48 hours. The powder X-ray diffraction pattern of this 15 compound is shown in Figure 2a.
Li2Mn4Og was synthesized by reaction of LiOH and MnCO3 at 345C for 32 hours. The powder X-ray diffraction pattern of this compound is shown in Figure la. The pattern is predominantly characteristic of the Li2Mn4Og defect spinel phase, but contains 20 in addition a few very weak peaks, for example at 4220 and 5302a, that are indicative of a very minor proportion of lithiated ~-MnO2 phase.
A cell of the format Li2Mn4O9/Electrolyte/LiMn2O4 (2) was then constructed. The electrolyte used was lM LiCl04 in propylene - ~ 21153~7 ` 13 ~ -carbonate. The first 9 charge and 8 discharge cycles of the cell are shown in Figure 11. A current of 0,1mA was employed for both charge and discharge. The cell was cycled between upper and lower voltage limits of 1,5V and 0,45V respectively. ~-In view thereof that a Li/Li4Mn5OI2 cell delivers on discharge 150mAh/g at an average voltage of approximately 2,7V, as indicated in Figure 4, and a Li/Lil03Mnlg7O4 cell delivers on discharge 100mAh/g at an average voltage of approximately 3,9V, 10 as indicated in Figure 9, a cell in accordance with the invention and having the configuration Li4Mn5OI2/Electrolyte/ Lil03Mnl~704 (3) was constructed.
The Lil03Mnl97O4 spinel compound of the cathode was synthesized by the reaction of LiOH and ~-MnO2 (chemically-prepared manganese dioxide, CMD) firstly at 450C for 48 hours and thereafter at 650C for 48 hours. The powder X-ray diffraction pattern of this compound is shown in Figure 2b.
Li4Mn5OI2 was synthesized by the reaction of Li2CO3 and MnCO3 at 400OC for 10 hours. The powder X-ray diffraction pattern of this 20 compound is shown in Figure lb. The patt,ern is predominantly characteristic of the Li4Mn5OI2 spinel phase.
A cell of the Eormat Li4Mn5OI2/Electrolyte/Lil03Mnlg~O4 (3) was then '~
constructed. The electrolyte used was lM LiCl04 in propylene carbonate. The first 5 charge/discharge cycles of the cell are -~
21~387 ;~
shown in Figure 12. A current of 0,lmA was employed for both charge and discharge. The cell was cycled between upper and lower voltage limits of 1,6V and 0,5V respectively.
In view thereof that a Li/Li4Tisol2 cell delivers on discharge 120~Ah/g at an average voltage of approximately 1,5V, as indicated in Figure 5, and a Li/LilO3Mnl~O4 cell delivers on discharge lOOmAh/g at an average voltage of approximately 3,9V, as indicated in Figure 9, a cell in accordance with the invention and having the configuration Li4Ti5OI2/Electrolyte/ Lil03Mnl~O4 (4) was constructed.
The Lil03Mnl~O4 spinel compound of the cathode was synthesized as in Example 2.
Li4Ti5OI2 was synthesized by the reaction of Li2CO3 and Tio2, using a Li/Ti atomic ratio of 0,87, at 500C for 12 hours and at 1000C
for 24 hours. A slight excess of lithium was used because of the volatility of Li2O at that temperature. The powder X-ray diffraction pattern of this compound is shown in Figure lc. The pattern is predominantly characteristic of the Li4Ti5OI2 spinel phase.
A cell of the format Li4Ti5OI2/Electrolyte/Lil~Mnl~O4 (4) was then constructed. The electrolyte used was lM LiCl04 in propylene carbonate. The first 7 charge/discharge cycles of the cell are shown in Figure 13. A current of 0,lmA was employed for both .
,,.~,. -.,; - . . ... . .
21~ 5387 ~ , charge and discharge. The cell was cycled between upper and lower voltage limits of 2,8V and 1,9V respectively.
In view thereof that a Li/Li4TisOI2 cell delivers on discharge 120mA.Hrs/g at an average voltage of approximately 1,5V, as indicated in Figure 5, and a Li/LiCoO2 cell delivers on discharge 140mA.Hrs/g at an average voltage of approximately 3,9V, as indicated in Figure 10, a cell in accordance with the invention and having the configuration Li4Ti5OI2/Electrolyte/LiCoO2 (5) was constructed.
The LiCoO2 spinel compound of the cathode was synthesized by the reaction of CoC03 and Li2CO3 firstly at 400C for 48 hours and thereafter at 900C for 48 hours. The powder X-ray diffraction pattern of this compound is shown in Figure 2c.
Li4Ti5OI2 synthesized as in Example 3, was used for the anode in this example.
A cell of the format Li4TisOI2/Electrolyte/LiCoO2 (5) was then constructed. The electrolyte used was lM LiCoO4 in propylene carbonate. The first 3 charge/discharge cycles of the cell are shown in Figure 14. A current of 0,lmA was employed for both charge and discharge. The cell was cycled between upper and lower voltage limits of 2,8V and 1,9V respectively.
16 21~5387 EXAMPLE_ 5 In view thereof that a Li/LiFe5O8 cell delivers on discharge lOOmAh/g at an average voltage of approximately 1,OV, as ~;-indicated in Figure 6, and a Li/Lil05Mnl9704 cell delivers on 5 discharge lOOmAh/g at an average voltage of approximately 3,9V, as indicated in Figure 9, a cell in accordance with the invention -and having the configuration LiFe5O8/Electrolyte/Lil03Mnl97O4 (6) was constructed.
The Lil03Mnl~7O4 spinel compound of the cathode was synthesized as in Example 2.
LiFe5O8 was synthesized by reacting of Li2CO3 and o~-Fe2O3 in a 1:5 molar ratio at 900C for 24 hours. The powder X-ray diffraction pattern of this compound is shown in Figure ld.
A cell of the format LiFe5O8/Electrolyte/Lil03Mn~97O4 (6) was then 15 constructed. The electrolyte used was lM LiClO~ in propylene carbonate. The first charge cycle of the cell is shown in Figure 15a. A current of 0,lmA was employed for both charge and discharge. The cell had an upper voltage limit of 4,lV. ~
:
20 In view thereof that a Li/Li-Fe-Ti oxide spinel cell delivers on discharge 80mAh/g at an average voltage of approximately 0,6V, as indicated in Figure 7, and a Li/Lil03Mnl 9704 cell delivers on discharge lOOmAh/g at an average voltage of approximately 3,9V, as indicated in Figure 9, a cell in accordance with the invention 21~387 and having the configuration Li-Fe-Ti oxide spinel/Electrolyte/
Li103Mnl9704 (7~ was constructed.
The LilO3Mnl~O4 spinel compound of the cathode was synthesized as in Example 2.
A Li-Fe-Ti oxide spinel was synthesized by the reaction of Li2CO3 and Fe2TiO5, using a Li:Fe:Ti atomic ratio of 2:2:1, at 500C for 6 hours and at 900C for 16 hours. The powder X-ray diffraction pattern of this compound is shown Figure le. The pattern is ~ ;
predominantly characteristic of a spinel-type phase. ~ -~
A cell of the format Li-Fe-Ti oxide spinel/Electrolyte/Lil03Mnl~O4 (7) was then constructed. The electrolyte used was lM LiCl04 in propylene carbonate. The first charge cycle of the cell is shown in Figure 15b. A current of 0,lmA was employed for both charge ~-and discharge. The cell had an upper voltage limit of 4,4V.
A Li-Fe-Ti oxide spinel was synthesized by the reaction Li2Co3 and Fe2TiO3 using a Li:Fe:Ti atomic ratio of 1:2:1 at 500C for 6 hours, and thereafter at 900C for 16 hours. A cyclic voltammogram of a Li/Li-Fe-Ti oxide spinel cell with an electrolyte of lM LiC04 in propylene carbonate is shown in Figure ; ;~
16. It shows the rechargeable characteristics of the Li-Fe-Ti ` :
oxide spinel electrode, and in particular, the rechargeability of the Li insertion/extraction reaction that occurs at approximately 1,5V versus lithium.
Examples 5, 6 and 7 show, in particular, the potential of using spinel-type oxides containing iron as anodes because they provide a low voltage against lithium. Furthermore, the experimental data provided in the examples demonstrate the ability of transition metal oxides to provide an electrochemical couple for 'rocking chair' rechargeable lithium cells in which lithium ions are transported between the two transition metal oxide electrodes, the anode of which has a spinel-type structure, and which uses a liquid or polymeric electrolyte containing ~i+ ions.
The electrochemical cells of the invention thus contain no metallic lithium anode, and are therefore inherently safer than lithium cells containing metallic lithium anodes and, indeed, lithium-carbon anodes. In particular, such cells have an added advantage of providing a more constant operating voltage than cells with carbon anodes. Although the cells of the invention are designed primarily for the use as rechargeable cells, they can also, as indicated hereinbefore, be utilized as primary cells, if desired.
Although the principles of this invention have been demonstrated by use of lithium-metal oxide compounds, the compounds of the electrodes, instead of being oxides, can be sulphides.
~, . . . .
` 2 ~ :~
211~387 `~
ELECTROCHEMICAL CELL
THIS INVENTION relates to an electrochemical cell. :
-According to the invention, there is provided an electrochemical cell, which comprises as at least part of an anode, a lithium transition metal oxide or sulphide compound which has a [B2]X4n- spinel-type framework structure of an A[B2]X4 spinel wherein A and B are metal cations selected from Li, Ti, V, Mn, Fe and Co, X is oxygen (O) or sulphur (S), and n- refers to the overall charge of the ~:.
structural unit [B2]X4 of the framework structure, and the transition metal cation of which in its fully discharged state has a mean oxidation state greater than +3 for Ti, +3 for V, +3,5 for Mn, +2 for Fe and +2 for Co;
;.
as at least part of a cathode, a lithium metal oxide or -sulphide compound; and an electrically insulative lithium containing liquid or polymeric electronically conductive electrolyte between the anode ~ ~-and the cathode, such that, on discharging the cell, lithium ions ~`-` 2~1~387 are extracted from the spinel-type framework structure of the anode, with the oxidation state of the metal ions of the anode thereby increasing, while a concomitant insertion of lithium ions into the compound of the cathode takes place, with the oxidation state of the metal ions of the cathode decreasing correspondingly.
The compounds of the anode and cathode may, in particular, be lithium metal oxide compounds.
While the cell can be a primary cell, it is envisaged that it may, in particular, be a rechargeable or secondary cell in which the reverse reactions to those set out above, take place during charging of the cell.
Thus, spinel compounds have structures that can be represented by the general formula A[B2] X4 given hereinbefore, and in which the X atoms are ideally arranged in a cubic-close-packed fashion to form a negatively charged anion array comprised of face-sharing and edge-sharing X tetrahedra and octahedra. In the formula A~B2] X4, the A cations and B cations occupy tetrahedral and octahedral sites respectively. In the ideal spinel structure, with the origin of the unit cell at the centre (3m), the close-packed anions are located at the 32e positions of the space group Fd3m. Each unit cell contains 64 tetrahedral interstices situated at three crystallographically non-equivalent positions 8a, 8b and 48f, and 32 octahedral interstices situated at the crystallographically non-equivalent positions 16c and 16d.
3 21~387 ,t In the A[B2]X4 spinel, the A cations reside in ~he 8a tetrahedral interstices and the B cations in the 16d octahedral interstices.
There are thus 56 empty tetrahedral and 16 empty octahedral sites ~, per cubic unit cell.
'I
The framework structure of the lithium metal oxide compound of the anode thus has, as its basic structural unit, a unit of the formula [B2] X4~ as hereinbefore described.
In the anode of the cell of the present invention, therefore, the B cations of the [B2]X4~ host framework structure may be regarded as being located at the 16d octahedral positions, and the X
anions as being located at the 32e positions of the spinel structure. The tetrahedra defined by the 8a, 8b and 48f ` positions and the octahedra defined by the 16c positions of the spinel structure thus form the interstitial space of the [B2] X4 framework structure for the diffusion of mobile Li+ cations.
The B cations of the framework structure may consist of one cationic type, or more than one cationic type of identical or mixed valence to provide various [B2]X4~ framework structures, the overall charge of which can vary over a wide range.
Spinel compounds having the [B2] X4~ framework structure may also be characterized by crystallographic space groups other than the prototypic cubic space group Fd3m, and may therefore not have the ideal cubic-close-packed structures hereinbefore described. For example, in Lil+jc[Mn2] 04 compounds with O~x~1, ie compounds in .~, .~i . . . .
`~
211 ~ 3~7 s which A is Li, and B is Mn, the spinel structure is distorted, as a result of the Jahn-Teller Mn3+ octahedral site ions, to I tetragonal symmetry, and the compound is characterized by the !;i tetragonal space groups F41/ddm, or, alternatively, I4l/amd in which the tetrahedral and octahedral site nomenclature differs from that as de~ined by the space group Fd3m.
Furthermore, the anode need not necessarily be a stoichiometric spinel compound, but can instead be a defect spinel. Defect spinels are well known in the large family of spinel compounds ~ 10 and can have vacancies on the A sites, or on the B sites, or on i both the A sites and B sites. For example, compounds can be ~ synthesized in which defects are created by varying the quantity !~ of B cations in the framework structure such that additional Li+
cations can enter and.leave the framework. .I.n these instances additional Li+ cations can partially occupy the 16d octahedral sites normally occupied by the B-type cations. Under such ~ circumstances these partially occupied octahedra can be ;~ considered to form part of the interstitial space. Conversely, ~: compounds can also be synthesi~ed, in which part of the ~ . 20 interstitial space defined by the 8a, 8b and 48f tetrahedral and 1 16c octahedral interstices of the spinel structure can be occupied by B-type cations, thereby rendering these particular sites at least partially inaccessible to the mobile Li cations.
The [B2] X4~ framework structure can contain in certain instances a minor proportion, typically less than 10 atomic percent, of cations other than the mobile Li-type cations, or the A and B-type cations, within the framework structure or within the 2 ~ 8 7 interstitial spaces of the framework structure, and that could serve to stabilize the structure. For example, doped spinels of stoichiometry Lil+5Mn2,~04 where O~sO,l, for example, Li~03Mnl9704 in which ~=0,03, and LiM~2Mn2s04 where M=Mg or Zn and O~sO,05, for 3 5 example, LiMgOO25Mnl9504, are more stable to cycling than the stoichiometric spinel LiMn204.
The compound of the anode may be a stoichiometric spinel selected from the group comprising Li4Mn5012, which can be written as (Li)sa[Lio33Mnl67]l6do4 in ideal spinel notation; Li4Ti5o12, which can be written as (Li)ga[Lio33Ti167]16dO4 in ideal spinel notation; LiTi2o4 which can be written as (Li)8a[Ti2]16d4 in ideal spinel notation;
¦~ LiV2o4, which can be written as (Li)8a[V2]16dO4 in ideal spinel notation; and LiFe508, which can be written as (Fe)8a[Fe15LiO,5]16d4 in ideal spinel notation.
Instead, the compound of the anode may be a defect spinel selected from the group comprising Li2Mn409, which can be written as (LiO,89Cb,ll)8a[Mnl~78~0~22]l6do4 in spinel notation; and Li2Ti307, which can be written as (Lio8900~5)8a[Ti~7~Lio29]~6do4 in spinel notation. In defect spinels, the distribution of Li+ on the A and B sites can vary from compound to compound.
Instead, the compound of the anode may have a spinel-type structure, which can be a stoichiometric or defect spinel, with a mixture of transition metal cations such as a lithium-iron-titanium oxide in which the lithium and iron cations ~i ~ 211~387 are located on the A-sites, and lithium, iron and titanium cations on the B-sites.
In a preferred embodiment of the invention, the transition metal cations, Ti, V, Mn, Fe and Co, reside predominantly or completely on the B-sites of the spinel structure, while the Li cations reside predominantly or completely on the A-sites of the .:
structure.
~ ',, .
The lithium metal oxide compound of the cathode may also have a spinel-type framework structure. Thus, the framework structure of the lithium metal oxide compound of the cathode may then also have, as its basic structural unit, a unit of the formula [B2]X4n-of an A[B2]X4 spinel, as hereinbefore described, with the transition metal cations of the anode being more electropositive than those of the cathode.
~: .
In the compound of the cathode, A and B may be a metal cation of one type, or a mixture of different metal cations. The compound of the cathode may be a stoichiometric or defect spinel compound, as hereinbefore described.
: .
When the compound of the cathode has a spinel-type structure, it may be selected from the group having as its B-type cations hi, Mn, Co or Ni, or mixtures thereof, such as Li~Mn2O4 where O~x~1 and Li~Co2O4 where O~xs2, optionally doped with additional metal ~; cations to stabilize the structure as hereinbefore described.
:~
:
~i 21~387 Instead, the compound of the cathode may have another structure type, for example a layered type structure such as that found within a system defined by a formula Li~Col~NiyO2 where Osysl and ~ O~xsl.
¦ 5 In general, the anode compound will be selected from those spinel compounds that offer a relatively low voltage vs pure lithium, typically those that offer 3V or less, while the cathode compound will be selected from those spinel compounds that offer a relatively high voltage vs pure lithium, typically those that offer between 4,5V and 3V. For example, a Li/Li4+XTisOl2 cell ~ delivers on discharge at lOO~A/cm2 (for O<x~1) an average voltage 3 of approximately 1,5V, while a Li/Li~Mn204 cell delivers on discharge at lOO~A/cm2 (for O<x~1) an average voltage of approximately 4V. Therefore, a cell in accordance with the invention can have Li4+~Ti50l2 as an anode and Li~Mn204 as a cathode, : ::
and will deliver approximately 2,5V on discharge and which is approximately twice the voltage of a nickel-cadmium cell. In another example, a Li/Li2Mn409 cell delivers a voltage of ~ approximately 2,8V over most of the discharge. Thus, a cell in :
accordance with the invention can have a Li2+~Mn409 anode and Li~Mn204 as cathode, and delivers approximately 1,2V on discharge, which is the typical voltage of a nickel-cadmium cell. It is convenient to load such cells in a discharged state, ie with the following configurations:
Li4Ti50~2/Electrolyte/LiMn204 .... (1) Li2Mn409/Electrolyte/LiMn204 ..... (2) . ,~ " . . . ~ - -. ~'".. '' ' .. ' ' ' - ~ ' ' ~ ' . -~,,""
Although it is convenient to load such cells in a discharged state, the cells may also be loaded in the charged state, if so desired. In this respect, the anodes of the invention have lithiated spinel structures and delithiated spinel structures that have the [B2]X4 spinel framework as defined hereinbefore. - -~: ' In (1), Li+ ions are extracted from Li[Mn2]04 during charge with a concomitant oxidation of the manganese ions from an average :~
valence of 3,5 to higher values, and inserted into the Li4Ti50l2 ~ :-electrode structure with a concomitant reduction of the titanium cations from the average valence state of +4 to lower values.
During this process Li~ ions are shuttled between the oxide structures without the formation of any metallic lithium, the cell voltage being derived from changes in the oxidation state of the transition metal cations in the -anode and cathode structures.
The electrolyte may be a room temperature electrolyte such as LiCl04, LiBF4, or LiPF6 dissolved in an appropriate organic salt such as propylene carbonate, ethylene carbonate, dimethyl carbonate, dimethoxyethane, or appropriate mixtures thereof.
Instead, however, it may be any appropriate polymeric electrolyte such as polyethylene oxide (PE0) - LiCl04, PE0 - LiSo3CF3 and PE0 - LiN(CF3So2) 2~ that operates at room temperature or at elevated temperature, eg at about 120C.
~ 211~387 The invention will now be described by way of non-limlting examples, and with reference to the accompanying drawings in which:
FIGURE l shows powder X-ray diffraction patterns of compounds suitable for use as anode materials in rechargeable electrochemical cells according to the invention; :~
FIGURE 2 shows powder X-ray diffraction patterns of compounds suitable for use as cathode materials in rechargeable electrochemical cells according to the invention; ;;
FIGURE 3 shows a plot of voltage vs capacity for a known Li/Li2Mn4Og cell;
FIGURE 4 shows a plot of voltage vs capacity for a known Li/Li4Mn5O12 cell; `
FIGURE 5 shows a plot of voltage vs capacity for a known 15 Li/Li4Ti5OI2 cell;
FIGURE 6 shows a plot of voltage vs capacity for a known Li/LiFesO8 cell;
: FIGURE 7 shows a plot of voltage vs capacity for a ; ;
Li/Li-Fe-Ti oxide cell;
FIGURE 8 shows a plot of voltage vs capacity for a known Li/LiMn2O4 cell;
FIGURE 9 shows a plot of voltage vs capacity for a known Li/Li~03Mnl~O4 cell;
FIGURE lO shows a plot of voltage vs capacity for a known : :~
25 Li/LiCoO2 cell;
FIGURE ll shows a plot of voltage vs capacity for the cell of Example l and which is in accordance with the invention;
~?~
~ 2~5387 FIGURE 12 shows a plot of voltage vs capacity for the cell of Example 2 and which is in accordance with the invention; -:
FIGURE 13 shows a plot of voltage vs capacity for the cell of Example 3 and which is in accordance with the invention; -~`
.~
FIGURE 14 shows a plot of voltage vs capacity for the cell of Example 4 and which is in accordance with the invention;
FIGURE 15 shows plots of voltage vs capacity for the cells of Examples 5 and 6 and which are in accordance with the invention; and FIGURE 16 shows a cyclic voltammogram of the Li/Li-Fe-Ti oxide spinel cell of Example 7.
.
The following stoichiometric spinel and defect spinel compounds were selected for use as anode materials in the examples following hereinafter~
a) Li2Mn4Og b) Li4MnsOl2 c ) Li4Ti5OI2 d) LiFe5O8 e) Li-Fe-Ti oxide spinel in which Li:Fe:Ti=2:2:1 Powder X-ray diffraction patterns of these compounds are given in Figure la-e respectively.
The following spinel and non-spinel compounds were selected for use as cathode materials in the examples following hereinafter:
a) LiMn2O~ (spinel-type structure) b) Lil03Mnl g704 (spinel-type structure) c) LiCoO2 (layered-type structure) `' 12 2~ 387 Powder X-ray diffraction patterns of these compounds are given in Figure 2a-c respectively.
In view thereof that a Li/Li2Mn4Og cell delivers on discharge 150mAh/g at an average voltage of approximately 2,8V, as indicated in Figure 3, and a Li/LiMn2O4 cell delivers on discharge 120mAh/g at an average voltage of approximately 3,8V, as indicated in Figure 8, a cell in accordance with the invention a n d h a v i n g t h e c o n f i g u r a t i o n Li2Mn4Og(anode)/Electrolyte/LiMn2O4(cathode) (2) was constructed.
The LiMn2O4 spinel compound of the cathode was synthesized by reaction oE LiOH and ~-MnO2 (chemically-prepared manganese dioxide, CMD) firstly at 450C for 48 hours and thereafter at 750C for 48 hours. The powder X-ray diffraction pattern of this 15 compound is shown in Figure 2a.
Li2Mn4Og was synthesized by reaction of LiOH and MnCO3 at 345C for 32 hours. The powder X-ray diffraction pattern of this compound is shown in Figure la. The pattern is predominantly characteristic of the Li2Mn4Og defect spinel phase, but contains 20 in addition a few very weak peaks, for example at 4220 and 5302a, that are indicative of a very minor proportion of lithiated ~-MnO2 phase.
A cell of the format Li2Mn4O9/Electrolyte/LiMn2O4 (2) was then constructed. The electrolyte used was lM LiCl04 in propylene - ~ 21153~7 ` 13 ~ -carbonate. The first 9 charge and 8 discharge cycles of the cell are shown in Figure 11. A current of 0,1mA was employed for both charge and discharge. The cell was cycled between upper and lower voltage limits of 1,5V and 0,45V respectively. ~-In view thereof that a Li/Li4Mn5OI2 cell delivers on discharge 150mAh/g at an average voltage of approximately 2,7V, as indicated in Figure 4, and a Li/Lil03Mnlg7O4 cell delivers on discharge 100mAh/g at an average voltage of approximately 3,9V, 10 as indicated in Figure 9, a cell in accordance with the invention and having the configuration Li4Mn5OI2/Electrolyte/ Lil03Mnl~704 (3) was constructed.
The Lil03Mnl97O4 spinel compound of the cathode was synthesized by the reaction of LiOH and ~-MnO2 (chemically-prepared manganese dioxide, CMD) firstly at 450C for 48 hours and thereafter at 650C for 48 hours. The powder X-ray diffraction pattern of this compound is shown in Figure 2b.
Li4Mn5OI2 was synthesized by the reaction of Li2CO3 and MnCO3 at 400OC for 10 hours. The powder X-ray diffraction pattern of this 20 compound is shown in Figure lb. The patt,ern is predominantly characteristic of the Li4Mn5OI2 spinel phase.
A cell of the Eormat Li4Mn5OI2/Electrolyte/Lil03Mnlg~O4 (3) was then '~
constructed. The electrolyte used was lM LiCl04 in propylene carbonate. The first 5 charge/discharge cycles of the cell are -~
21~387 ;~
shown in Figure 12. A current of 0,lmA was employed for both charge and discharge. The cell was cycled between upper and lower voltage limits of 1,6V and 0,5V respectively.
In view thereof that a Li/Li4Tisol2 cell delivers on discharge 120~Ah/g at an average voltage of approximately 1,5V, as indicated in Figure 5, and a Li/LilO3Mnl~O4 cell delivers on discharge lOOmAh/g at an average voltage of approximately 3,9V, as indicated in Figure 9, a cell in accordance with the invention and having the configuration Li4Ti5OI2/Electrolyte/ Lil03Mnl~O4 (4) was constructed.
The Lil03Mnl~O4 spinel compound of the cathode was synthesized as in Example 2.
Li4Ti5OI2 was synthesized by the reaction of Li2CO3 and Tio2, using a Li/Ti atomic ratio of 0,87, at 500C for 12 hours and at 1000C
for 24 hours. A slight excess of lithium was used because of the volatility of Li2O at that temperature. The powder X-ray diffraction pattern of this compound is shown in Figure lc. The pattern is predominantly characteristic of the Li4Ti5OI2 spinel phase.
A cell of the format Li4Ti5OI2/Electrolyte/Lil~Mnl~O4 (4) was then constructed. The electrolyte used was lM LiCl04 in propylene carbonate. The first 7 charge/discharge cycles of the cell are shown in Figure 13. A current of 0,lmA was employed for both .
,,.~,. -.,; - . . ... . .
21~ 5387 ~ , charge and discharge. The cell was cycled between upper and lower voltage limits of 2,8V and 1,9V respectively.
In view thereof that a Li/Li4TisOI2 cell delivers on discharge 120mA.Hrs/g at an average voltage of approximately 1,5V, as indicated in Figure 5, and a Li/LiCoO2 cell delivers on discharge 140mA.Hrs/g at an average voltage of approximately 3,9V, as indicated in Figure 10, a cell in accordance with the invention and having the configuration Li4Ti5OI2/Electrolyte/LiCoO2 (5) was constructed.
The LiCoO2 spinel compound of the cathode was synthesized by the reaction of CoC03 and Li2CO3 firstly at 400C for 48 hours and thereafter at 900C for 48 hours. The powder X-ray diffraction pattern of this compound is shown in Figure 2c.
Li4Ti5OI2 synthesized as in Example 3, was used for the anode in this example.
A cell of the format Li4TisOI2/Electrolyte/LiCoO2 (5) was then constructed. The electrolyte used was lM LiCoO4 in propylene carbonate. The first 3 charge/discharge cycles of the cell are shown in Figure 14. A current of 0,lmA was employed for both charge and discharge. The cell was cycled between upper and lower voltage limits of 2,8V and 1,9V respectively.
16 21~5387 EXAMPLE_ 5 In view thereof that a Li/LiFe5O8 cell delivers on discharge lOOmAh/g at an average voltage of approximately 1,OV, as ~;-indicated in Figure 6, and a Li/Lil05Mnl9704 cell delivers on 5 discharge lOOmAh/g at an average voltage of approximately 3,9V, as indicated in Figure 9, a cell in accordance with the invention -and having the configuration LiFe5O8/Electrolyte/Lil03Mnl97O4 (6) was constructed.
The Lil03Mnl~7O4 spinel compound of the cathode was synthesized as in Example 2.
LiFe5O8 was synthesized by reacting of Li2CO3 and o~-Fe2O3 in a 1:5 molar ratio at 900C for 24 hours. The powder X-ray diffraction pattern of this compound is shown in Figure ld.
A cell of the format LiFe5O8/Electrolyte/Lil03Mn~97O4 (6) was then 15 constructed. The electrolyte used was lM LiClO~ in propylene carbonate. The first charge cycle of the cell is shown in Figure 15a. A current of 0,lmA was employed for both charge and discharge. The cell had an upper voltage limit of 4,lV. ~
:
20 In view thereof that a Li/Li-Fe-Ti oxide spinel cell delivers on discharge 80mAh/g at an average voltage of approximately 0,6V, as indicated in Figure 7, and a Li/Lil03Mnl 9704 cell delivers on discharge lOOmAh/g at an average voltage of approximately 3,9V, as indicated in Figure 9, a cell in accordance with the invention 21~387 and having the configuration Li-Fe-Ti oxide spinel/Electrolyte/
Li103Mnl9704 (7~ was constructed.
The LilO3Mnl~O4 spinel compound of the cathode was synthesized as in Example 2.
A Li-Fe-Ti oxide spinel was synthesized by the reaction of Li2CO3 and Fe2TiO5, using a Li:Fe:Ti atomic ratio of 2:2:1, at 500C for 6 hours and at 900C for 16 hours. The powder X-ray diffraction pattern of this compound is shown Figure le. The pattern is ~ ;
predominantly characteristic of a spinel-type phase. ~ -~
A cell of the format Li-Fe-Ti oxide spinel/Electrolyte/Lil03Mnl~O4 (7) was then constructed. The electrolyte used was lM LiCl04 in propylene carbonate. The first charge cycle of the cell is shown in Figure 15b. A current of 0,lmA was employed for both charge ~-and discharge. The cell had an upper voltage limit of 4,4V.
A Li-Fe-Ti oxide spinel was synthesized by the reaction Li2Co3 and Fe2TiO3 using a Li:Fe:Ti atomic ratio of 1:2:1 at 500C for 6 hours, and thereafter at 900C for 16 hours. A cyclic voltammogram of a Li/Li-Fe-Ti oxide spinel cell with an electrolyte of lM LiC04 in propylene carbonate is shown in Figure ; ;~
16. It shows the rechargeable characteristics of the Li-Fe-Ti ` :
oxide spinel electrode, and in particular, the rechargeability of the Li insertion/extraction reaction that occurs at approximately 1,5V versus lithium.
Examples 5, 6 and 7 show, in particular, the potential of using spinel-type oxides containing iron as anodes because they provide a low voltage against lithium. Furthermore, the experimental data provided in the examples demonstrate the ability of transition metal oxides to provide an electrochemical couple for 'rocking chair' rechargeable lithium cells in which lithium ions are transported between the two transition metal oxide electrodes, the anode of which has a spinel-type structure, and which uses a liquid or polymeric electrolyte containing ~i+ ions.
The electrochemical cells of the invention thus contain no metallic lithium anode, and are therefore inherently safer than lithium cells containing metallic lithium anodes and, indeed, lithium-carbon anodes. In particular, such cells have an added advantage of providing a more constant operating voltage than cells with carbon anodes. Although the cells of the invention are designed primarily for the use as rechargeable cells, they can also, as indicated hereinbefore, be utilized as primary cells, if desired.
Although the principles of this invention have been demonstrated by use of lithium-metal oxide compounds, the compounds of the electrodes, instead of being oxides, can be sulphides.
~, . . . .
Claims (20)
1. An electrochemical cell, which comprises as at least part of an anode, a lithium transition metal oxide or sulphide compound which has a [B2]X4n- spinel-type framework structure of an A[B2]X4 spinel wherein A and B are metal cations selected from Li, Ti, V, Mn, Fe and Co, X is oxygen (O) or sulphur (S), and n- refers to the overall charge of the structural unit [B2]X4 of the framework structure, and the transition metal cation of which in its fully discharged state has a mean oxidation state greater than +3 for Ti, +3 for V, +3,5 for Mn, +2 for Fe and +2 for Co;
as at least part of a cathode, a lithium metal oxide or sulphide compound; and an electrically insulative lithium containing liquid or polymeric electronically conductive electrolyte between the anode and the cathode, such that, on discharging the cell, lithium ions are extracted from the spinel-type framework structure of the anode, with the oxidation state of the metal ions of the anode thereby increasing, while a concomitant insertion of lithium ions into the compound of the cathode takes place, with the oxidation state of the metal ions of the cathode decreasing correspondingly.
as at least part of a cathode, a lithium metal oxide or sulphide compound; and an electrically insulative lithium containing liquid or polymeric electronically conductive electrolyte between the anode and the cathode, such that, on discharging the cell, lithium ions are extracted from the spinel-type framework structure of the anode, with the oxidation state of the metal ions of the anode thereby increasing, while a concomitant insertion of lithium ions into the compound of the cathode takes place, with the oxidation state of the metal ions of the cathode decreasing correspondingly.
2. A cell according to Claim 1, wherein the compounds of the anode and the cathode are lithium metal oxide compounds.
3. A cell according to Claim 1 wherein, in the compound of the anode, B is a single transition metal cation type.
4. A cell according to Claim 1 wherein, in the compound of the anode, B is a mixture of different transition metal cations.
5. A cell according to Claim 1, wherein the compound of the anode is a stoichiometric spinel selected from the group comprising Li4Mn5O12, which can be written as (Li)8a[Li0.33Mn1.67]16dO4 in ideal spinel notation; Li4Ti5O12, which can be written as (Li)8a[Li0.33Ti1.67]16dO4 in ideal spinel notation; LiTi2O4 which can be written as (Li)8a[Ti2]16dO4 in ideal spinel notation; LiV2O4, which can be written as (Li)8a[V2]16dO4 in ideal spinel notation; and LiFe5O8, which can be written as (Fe)8a[Fe1.5Li0.5]16dO4 in ideal spinel notation.
6. A cell according to Claim 1, wherein the compound of the anode is a defect spinel selected from the group comprising Li2Mn4O9, which can be written as (Li0.89?0.11) 8a[Mn1.78?0.22]16dO4 in spinel notation; and Li2Ti3O7, which can be written as (Li0.85?0.15) 8a[Ti1.71Li0.29]16dO4 in spinel notation.
7. A cell according to Claim 1, wherein the compound of the anode is a lithium-iron-titanium oxide having a spinel-type structure and in which lithium and iron cations are located on the A-sites, and lithium, iron and titanium cations on the B-sites.
8. A cell according to Claim 1 wherein, in the compound of the anode, the [B2]X4 framework structure contains, within the framework structure or within the interstitial spaces of the framework structure, additional metal cations to the lithium ions and the A and B cations to stabilize the structure, with the additional metal cations being present in an amount less than 10 atomic percent.
9. A cell according to Claim 1, wherein the lithium metal oxide compound of the cathode also has a spinel-type framework structure.
10. A cell according to Claim 9, wherein the framework structure of the lithium metal oxide compound of the cathode has as its basic structural unit, a unit of the formula [B2]X4n-, where [B2]X4n- is the structural unit of an A[B2]X4 spinel, with the X
anions being arranged to form a negatively charged anion array, and wherein A is a lithium cation;
B is a metal cation;
X is oxygen (O); and n- refers to the overall charge of the structural unit [B2]X4 of the framework structure, with the transition metal cations of the anode being more electropositive than those of the cathode.
anions being arranged to form a negatively charged anion array, and wherein A is a lithium cation;
B is a metal cation;
X is oxygen (O); and n- refers to the overall charge of the structural unit [B2]X4 of the framework structure, with the transition metal cations of the anode being more electropositive than those of the cathode.
11. A cell according to Claim 10 wherein, in the compound of the cathode, B is a single metal cation type.
12. A cell according to Claim 10 wherein, in the compound of the cathode, B is a mixture of different metal cations.
13. A cell according to Claim 10, wherein the compound of the cathode is a spinel in which the B cation is selected from the group comprising Li, Mn, Co and Ni.
14. A cell according to Claim 10 wherein, in the compound of the cathode, the [B2]X4 framework structure contains, within the framework structure or within the interstitial spaces of the framework structure, additional metal cations to the lithium ions and the A and B cations to stabilize the structure, with the additional metal cations being present in an amount less than 10 atomic percent.
15. A cell according to claim 14, wherein the compound of the cathode is Li1+.delta.Mn2-.delta.O4 where 0<.delta.?0,1.
16. A cell according to Claim 14, wherein the compound of the cathode is LiM.delta./2Mn2-.delta.O4 where M=Mg or Zn and 0<.delta.?0,05.
17. A cell according to Claim 1, wherein the lithium metal oxide compound of the cathode has a layered-type structure conforming to the formula LixCo1-yNiyO2 where 0<x?1 and 0?y?1.
18. A cell according to Claim 1, wherein the anode compound offers a relatively low voltage of 3V or less against pure lithium, while the cathode compound offers a relatively high voltage of between 3V and 4,5V against pure lithium.
19. A cell according to Claim 1, wherein the electrolyte is a room temperature electrolyte selected from the group comprising LiClO4, LiBF4, and LiPF6 dissolved in an organic salt selected from the group comprising propylene carbonate, ethylene carbonate, dimethyl carbonate, dimethoxyethane and appropriate mixtures thereof.
20. A cell according to Claim 1, wherein the electrolyte is a polymeric electrolyte selected from the group comprising polyethylene oxide (PEO) - LiClO4, PEO - LiSO3CF3 and PEO -LiN(CF3SO2)2.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA936488 | 1993-09-02 | ||
| ZA93/6488 | 1993-09-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2115387A1 true CA2115387A1 (en) | 1995-03-03 |
Family
ID=25583205
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002115387A Abandoned CA2115387A1 (en) | 1993-09-02 | 1994-02-10 | Electrochemical cell |
Country Status (8)
| Country | Link |
|---|---|
| US (7) | US7452630B2 (en) |
| JP (1) | JP3523899B2 (en) |
| CA (1) | CA2115387A1 (en) |
| DE (1) | DE4412758A1 (en) |
| FR (1) | FR2709602B1 (en) |
| GB (1) | GB2281655B (en) |
| IL (1) | IL108572A (en) |
| ZA (1) | ZA94750B (en) |
Families Citing this family (32)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA94750B (en) * | 1993-09-02 | 1994-09-29 | Technology Finance Corp | Electrochemical cell |
| US6083644A (en) * | 1996-11-29 | 2000-07-04 | Seiko Instruments Inc. | Non-aqueous electrolyte secondary battery |
| JP4022265B2 (en) * | 1997-07-15 | 2007-12-12 | ソニー株式会社 | Lithium hydrogen titanate and method for producing the same |
| JP4768901B2 (en) * | 1999-06-03 | 2011-09-07 | チタン工業株式会社 | Lithium titanium composite oxide, method for producing the same, and use thereof |
| JP2002157998A (en) * | 2000-11-17 | 2002-05-31 | Yuasa Corp | Method of manufacturing composite positive electrode for solid lithium secondary battery and solid lithium secondary battery using same |
| KR100489509B1 (en) * | 2001-03-22 | 2005-05-16 | 마쯔시다덴기산교 가부시키가이샤 | Positive-electrode active material and nonaqueous-electrolyte secondary battery containing the same |
| JP4510331B2 (en) | 2001-06-27 | 2010-07-21 | パナソニック株式会社 | Nonaqueous electrolyte secondary battery |
| JP4836371B2 (en) | 2001-09-13 | 2011-12-14 | パナソニック株式会社 | Positive electrode active material and non-aqueous electrolyte secondary battery including the same |
| JP3827545B2 (en) * | 2001-09-13 | 2006-09-27 | 松下電器産業株式会社 | Positive electrode active material, method for producing the same, and nonaqueous electrolyte secondary battery |
| US8658125B2 (en) | 2001-10-25 | 2014-02-25 | Panasonic Corporation | Positive electrode active material and non-aqueous electrolyte secondary battery containing the same |
| US9391325B2 (en) | 2002-03-01 | 2016-07-12 | Panasonic Corporation | Positive electrode active material, production method thereof and non-aqueous electrolyte secondary battery |
| JP4197237B2 (en) | 2002-03-01 | 2008-12-17 | パナソニック株式会社 | Method for producing positive electrode active material |
| US8241790B2 (en) * | 2002-08-05 | 2012-08-14 | Panasonic Corporation | Positive electrode active material and non-aqueous electrolyte secondary battery containing the same |
| JP4554911B2 (en) * | 2003-11-07 | 2010-09-29 | パナソニック株式会社 | Nonaqueous electrolyte secondary battery |
| JP4582579B2 (en) * | 2004-12-07 | 2010-11-17 | Ａｇｃセイミケミカル株式会社 | Positive electrode material for lithium secondary battery |
| JP4439456B2 (en) * | 2005-03-24 | 2010-03-24 | 株式会社東芝 | Battery pack and automobile |
| CN1719642A (en) * | 2005-06-03 | 2006-01-11 | 北京化工大学 | Spinel type composite metal oxide electrode material and preparing process thereof |
| US20070111099A1 (en) * | 2005-11-15 | 2007-05-17 | Nanjundaswamy Kirakodu S | Primary lithium ion electrochemical cells |
| CN101213704B (en) * | 2006-01-25 | 2010-09-15 | 松下电器产业株式会社 | Non-aqueous electrolyte secondary cell, manufacturing method thereof, and mounting method thereof |
| US7820137B2 (en) | 2006-08-04 | 2010-10-26 | Enerdel, Inc. | Lithium titanate and method of forming the same |
| US8168330B2 (en) * | 2006-04-11 | 2012-05-01 | Enerdel, Inc. | Lithium titanate cell with reduced gassing |
| US7541016B2 (en) * | 2006-04-11 | 2009-06-02 | Enerdel, Inc. | Lithium titanate and method of forming the same |
| EP2104162B1 (en) * | 2008-03-18 | 2011-07-13 | Korea Institute of Science and Technology | Lithium-manganese-tin oxide cathode active material and lithium secondary cell using the same |
| JP5273491B2 (en) * | 2009-02-16 | 2013-08-28 | トヨタ自動車株式会社 | Lithium secondary battery |
| DE102009018804A1 (en) * | 2009-04-24 | 2010-10-28 | Li-Tec Battery Gmbh | Electrochemical cell with lithium titanate |
| WO2011093126A1 (en) * | 2010-01-28 | 2011-08-04 | 三菱電機株式会社 | Power storage device cell, process for producing same, method for storing same, and electricity storage device |
| KR101527995B1 (en) * | 2011-02-01 | 2015-06-10 | 주식회사 엘지화학 | Cathode Active Material Comprising Lithium Manganese Oxide Capable of Providing Excellent Charge-Discharge Characteristics at 3Ｖ Region as Well as 4Ｖ Region |
| JP6060607B2 (en) * | 2012-10-11 | 2017-01-18 | 株式会社豊田中央研究所 | Lithium ion battery and method of using the same |
| DE102014208228A1 (en) * | 2014-04-30 | 2015-11-05 | Robert Bosch Gmbh | Galvanic element and method for its production |
| CN104347880A (en) * | 2014-10-14 | 2015-02-11 | 东莞新能源科技有限公司 | Lithium ion battery capable of quick charging |
| CN106328926B (en) * | 2016-10-18 | 2020-03-27 | 湖南锂顺能源科技有限公司 | High-safety long-life ternary material battery |
| CN116190568B (en) * | 2023-04-25 | 2023-08-18 | 宁德新能源科技有限公司 | Secondary battery and electronic device |
Family Cites Families (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3545468A (en) * | 1969-05-06 | 1970-12-08 | Bowles Eng Corp | Liquid level controller employing vortex valve |
| AU532635B2 (en) | 1979-11-06 | 1983-10-06 | South African Inventions Development Corporation | Metal oxide cathode |
| JPS57152669A (en) | 1981-03-18 | 1982-09-21 | Sanyo Electric Co Ltd | Chargeable organic electrolyte battery |
| US4507371A (en) * | 1982-06-02 | 1985-03-26 | South African Inventions Development Corporation | Solid state cell wherein an anode, solid electrolyte and cathode each comprise a cubic-close-packed framework structure |
| JPS631708A (en) | 1986-06-23 | 1988-01-06 | Yutaka Giken:Kk | Sealed buffer for catalytic converter |
| CA1331506C (en) | 1988-07-12 | 1994-08-23 | Michael Makepeace Thackeray | Method of synthesizing a lithium manganese oxide |
| FR2638764B1 (en) * | 1988-11-04 | 1993-05-07 | Centre Nat Rech Scient | COMPOSITE ELEMENT COMPRISING A TITANIUM CHALCOGENIDE OR OXYCHALCOGENIDE LAYER, IN PARTICULAR AS A POSITIVE ELECTRODE IN A THIN-LAYER ELECTROCHEMICAL CELL |
| JP2797390B2 (en) * | 1989-04-03 | 1998-09-17 | ソニー株式会社 | Non-aqueous electrolyte secondary battery |
| JP3019326B2 (en) | 1989-06-30 | 2000-03-13 | 松下電器産業株式会社 | Lithium secondary battery |
| GB2242898B (en) * | 1990-04-12 | 1993-12-01 | Technology Finance Corp | Lithium transition metal oxide |
| DE4119944A1 (en) * | 1990-06-18 | 1991-12-19 | Technology Finance Corp | MANGANOXIDE COMPOUND |
| JPH0487268A (en) * | 1990-07-27 | 1992-03-19 | Seiko Electronic Components Ltd | Nonaqueous electrolyte secondary battery |
| US5147739A (en) | 1990-08-01 | 1992-09-15 | Honeywell Inc. | High energy electrochemical cell having composite solid-state anode |
| US5284721A (en) * | 1990-08-01 | 1994-02-08 | Alliant Techsystems Inc. | High energy electrochemical cell employing solid-state anode |
| JP3162437B2 (en) * | 1990-11-02 | 2001-04-25 | セイコーインスツルメンツ株式会社 | Non-aqueous electrolyte secondary battery |
| US5160172A (en) * | 1990-12-18 | 1992-11-03 | Abb Vetco Gray Inc. | Threaded latch ring tubular connector |
| CA2057946A1 (en) * | 1990-12-20 | 1992-06-21 | Michael M. Thackeray | Electrochemical cell |
| US5478671A (en) * | 1992-04-24 | 1995-12-26 | Fuji Photo Film Co., Ltd. | Nonaqueous secondary battery |
| ZA936168B (en) * | 1992-08-28 | 1994-03-22 | Technology Finance Corp | Electrochemical cell |
| JP3502118B2 (en) | 1993-03-17 | 2004-03-02 | 松下電器産業株式会社 | Method for producing lithium secondary battery and negative electrode thereof |
| ZA94750B (en) | 1993-09-02 | 1994-09-29 | Technology Finance Corp | Electrochemical cell |
-
1994
- 1994-02-03 ZA ZA94750A patent/ZA94750B/en unknown
- 1994-02-07 IL IL108572A patent/IL108572A/en not_active IP Right Cessation
- 1994-02-07 GB GB9402278A patent/GB2281655B/en not_active Expired - Lifetime
- 1994-02-10 CA CA002115387A patent/CA2115387A1/en not_active Abandoned
- 1994-03-08 JP JP03698994A patent/JP3523899B2/en not_active Expired - Fee Related
- 1994-04-06 FR FR9404024A patent/FR2709602B1/en not_active Expired - Lifetime
- 1994-04-13 DE DE4412758A patent/DE4412758A1/en not_active Ceased
-
2002
- 2002-08-27 US US10/228,734 patent/US7452630B2/en not_active Expired - Fee Related
-
2007
- 2007-10-31 US US11/931,490 patent/US7824804B2/en not_active Expired - Fee Related
-
2008
- 2008-10-24 US US12/258,224 patent/US7838149B2/en not_active Expired - Fee Related
-
2009
- 2009-01-14 US US12/353,785 patent/US7556890B2/en not_active Expired - Fee Related
- 2009-05-21 US US12/470,346 patent/US7722990B2/en not_active Expired - Fee Related
-
2010
- 2010-06-25 US US12/823,977 patent/US7855016B2/en not_active Expired - Fee Related
- 2010-12-17 US US12/972,066 patent/US7964310B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| US20080048615A1 (en) | 2008-02-28 |
| US20100264880A1 (en) | 2010-10-21 |
| GB2281655B (en) | 1996-10-30 |
| FR2709602B1 (en) | 1996-08-23 |
| US20090123836A1 (en) | 2009-05-14 |
| DE4412758A1 (en) | 1995-03-09 |
| US7964310B2 (en) | 2011-06-21 |
| IL108572A0 (en) | 1994-05-30 |
| ZA94750B (en) | 1994-09-29 |
| US7556890B2 (en) | 2009-07-07 |
| FR2709602A1 (en) | 1995-03-10 |
| US20090047581A1 (en) | 2009-02-19 |
| US20020197532A1 (en) | 2002-12-26 |
| US7722990B2 (en) | 2010-05-25 |
| JP3523899B2 (en) | 2004-04-26 |
| US20090253047A1 (en) | 2009-10-08 |
| US20110086277A1 (en) | 2011-04-14 |
| GB2281655A (en) | 1995-03-08 |
| US7452630B2 (en) | 2008-11-18 |
| US7838149B2 (en) | 2010-11-23 |
| GB9402278D0 (en) | 1994-03-30 |
| US7855016B2 (en) | 2010-12-21 |
| IL108572A (en) | 1998-02-08 |
| US7824804B2 (en) | 2010-11-02 |
| JPH0785878A (en) | 1995-03-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7964310B2 (en) | Electrochemical cell | |
| CA2104759C (en) | Electrochemical cell | |
| Gummow et al. | Lithium extraction from orthorhombic lithium manganese oxide and the phase transformation to spinel | |
| US6277521B1 (en) | Lithium metal oxide containing multiple dopants and method of preparing same | |
| US6582852B1 (en) | Metal oxide containing multiple dopants and method of preparing same | |
| Gao et al. | Novel LiNi1− x Ti x/2Mg x/2 O 2 Compounds as Cathode Materials for Safer Lithium‐Ion Batteries | |
| CA1331506C (en) | Method of synthesizing a lithium manganese oxide | |
| CA2270656C (en) | Nonaqueous electrolyte battery and charging method therefor | |
| US5750288A (en) | Modified lithium nickel oxide compounds for electrochemical cathodes and cells | |
| US5561006A (en) | Chargeable lithium electrochemical cell and method of manufacting it | |
| CA2068015A1 (en) | Electrode material | |
| WO1995001935A1 (en) | Novel materials for use as cathodes in lithium electrochemical cells | |
| US6551746B1 (en) | Rechargeable electrochemical cell of lithium ion or lithium alloy-type possessing metal oxide modified cathode structure with high first charge capacity | |
| KR19980703308A (en) | Lithium secondary battery | |
| EP1084516B1 (en) | Electrochemical cell | |
| JPH07320784A (en) | Nonaqeous electrolytic lithium secondary battery | |
| JPH1027609A (en) | Secondary battery with nonaqueous electrolyte | |
| Thirunakaran et al. | Electrochemical behaviour of LiM y Mn 2− y O 4 (M= Cu, Cr; 0≤ y≤ 0.4) | |
| Xia et al. | Studies on the Li Mn O spinel system (obtained from melt-impregnation method) as positive electrodes for 4 V lithium batteries. Part III. Characterization of capacity and rechargeability | |
| KR100269249B1 (en) | Licoxmn2-xo4 as positive electrode material for 5v lithium secondary batteries | |
| Thackeray et al. | Transition metal oxides for rocking-chair cells | |
| Pistoia et al. | STORAGE CHARACTERISTICS AND CAPACITY LOSSES OF Mn SPINELS FOR Li-ION BATTERIES | |
| Thackeray et al. | SPINEL ELECTRODES Li20. yMnO2 (y≥ 2.5) FOR RECHARGEABLE LITHIUM BATTERY APPLICATIONS | |
| KR19990018327A (en) | Lithium Spinel Compound Used as Cathode |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20010212 |