MXPA06005785A - Solid state synthesis of lithium-nickel-cobalt-manganese mixed metal oxides for use in lithium ion battery cathode material - Google Patents

Abstract

Single-phase lithium-transition metal oxide compounds containing cobalt, manganese and nickel can be prepared by wet milling cobalt-, manganese-, nickel- and lithium-containing oxides or oxide precursors to form a finely-divided slurry containing well-distributed cobalt, manganese, nickel and lithium, and heating the slurry to provide a lithium-transition metal oxide compound containing cobalt, manganese and nickel and having a substantially single-phase O3 crystal structure. Wet milling provides significantly shorter milling times than dry milling and appears to promote formation of single-phase lithium-transition metal oxide compounds. The time savings in the wet milling step more than offsets the time that may be required to dry the slurry during the heating step.

Description

SYNTHESIS IN SOLID STATE OF MIXED METALLIC OXIDES OF LITHIUM-NICKEL-COBALT-MANGANESE FOR USE IN A MATERIAL OF THE C ALL OF A LITHIUM ION BATTERY FIELD OF THE INVENTION This invention relates to the preparation of useful compounds or cathodes for lithium ion batteries. BACKGROUND OF THE INVENTION Lithium ion batteries typically include an anode, and an electrolyte and a cathode containing lithium in the form of a lithium transition metal oxide. The transition metal oxides that have been used include cobalt dioxide, nickel dioxide and manganese dioxide. BRIEF DESCRIPTION OF THE INVENTION Transition metal oxide compounds in which cobalt, manganese and nickel are each present in the lattice structure of the crystal can be referred to as quaternary cathode or four metal compounds. Single-phase lattice structures containing the appropriate amounts of these metals can provide especially desirable lithium ion battery cathodes. For example, quaternary compounds: Ref. 173155 LiNio.i no.iCOo.s02 (I) Li (Co <? / 3) Mn < ? / 3) Ni (1/3)) 02 (II) and Li (Li0.o8C? O.i5Mno.375Nio.375) 02 (III) are of interest if they are successfully formed as a single phase (if phases are present multiple, then there are-problems with the operation of the battery). The equimolar nickel and manganese content in these three compounds is especially desirable and is believed to contribute to the formation of a more stable crystal lattice structure. Unfortunately,. it may be difficult to form a single-phase quaternary compound containing the oobalt, manganese and nickel transition metals in a lattice structure of the lithium-containing crystal. The achievement of a single phase can be made easier by the exclusion of one or more of the transition metals of manganese- or nickel (for example, to manufacture a ternary or three-metal system such as LiNio.sCoo.2O2 or a binary or two-metal system such as LiCo02), but this can also reduce battery performance or introduce other problems. The • achievement of. a single-phase quaternary compound can be. achieved by co-precipitation of mixed hydroxides as recommended and used in the U.S. patent application. Do not. 2003/0022063 Al (Paulsen et al.) Entitled "LITHIATED OXIDE MATERIALS AND METHODS OF MANUFACTURE" and as used in examples 19 and 20 of the U.S. patent application. No. 2003/0027048 Al (Lu et al.) Entitled "CATHODE COMPOSITIONS FOR LITHIUM-ION BATTERIES". However, co-precipitation requires filtration, washing and repeated drying and therefore exhibits relatively limited performance and high manufacturing costs. Paulsen et al. it also describes and employs in its example 6 a sintering and milling process in a high energy-consumption ball mill for manufacturing certain lithium-transition metal oxide compounds having the formula Li (Li? C ?? (MnBNi? -z)? -? - y)? 2 (IV) 'where 0.4 £ Z < O.65, 0 < x < 0.16 and 0'.1 < and < 0.3. The U.S. patent No. 6,333,128 Bl (Sunagawa et al.) Entitled "LITHIUM '' SECONDARY BATTERY" uses in its examples Al a A9 a process of mixing, baking and grinding by the application of a jet, to a powder, to manufacture certain oxide compounds of lithium-transition metal having the formula: LiaC? bMncNi1-bc? 2 (V) where 0_ < a < l .2, 0.01 < b < O .4, 0'.01 < c < 0.4 and 0.02 < b + c < 0.5-. These processes by Pulsen et al. and Sunagawa et al. they involve reactions in the solid state and potentially offer higher performance and lower manufacturing costs-than processes based on co-precipitation. However, when trying to duplicate some of the compounds of -Paulsen et al. and Sunagawa et al. using the processes described, multiple phase compounds were obtained instead of the desired single phase structure. As well, when attempting to prepare the aforementioned compounds of formulas I to III (which fall out of formulas IV and V) using a solid state reaction, multi-phase compounds were obtained instead of the single-phase structure, desired. Using about 15% by weight of excess lithium, it was able to make compounds in the solid solution between LiCo02 and LiMn03 by the solid state reaction. Excess lithium helped the formation of a single-phase material, but the resulting product had poor electrochemical performance. It has now been found that single phase lithium transition metal oxide compounds containing cobalt, manganese and nickel can be prepared by: (a) wet grinding oxides or cobalt-containing oxide precursors, manganese, nickel and lithium to form a finely divided suspension containing well-distributed cobalt, manganese, nickel and lithium, and (b) to heat the suspension to provide a lithium-transition metal oxide compound containing cobalt, manganese and nickel and having a crystal structure of 03 substantially one phase. Wet milling provides significantly shorter grinding times than dry milling, and appears to promote the formation of single-phase lithium transition metal oxide compounds. The time savings in the wet milling stage far outweigh the time that may be required to dry the suspension during the heating stage. The invention provides, in another aspect, a process for manufacturing a lithium ion battery cathode comprising the additional step of mixing the particles of the lithium transition metal compound, described above, with conductive carbon and a binder, and coating the resulting mixture on a support substrate. The invention provides, in yet another aspect, a process for manufacturing a lithium ion battery comprising placing the cathode described above, an electrically compatible anode, a separator and an electrolyte in a container. The invention provides, in yet another aspect, the lithium transition metal oxide compounds (and a lithium ion battery comprising at least one compound) having the formula: LiaCObMncNii-b- - (VI) where 0 < al.2, 0.52 < b < 0.98, 0.01 < c < 0.47 and 0.53 < b + c < 0.99. The invention provides, in yet another aspect, a lithium-transition metal oxide composition (and a lithium ion battery comprising at least one composition) consisting essentially of a compound selected from the group consisting of the compounds of an single phase: LiNi0.?Mno.??????????????????????????????????????????????????????????????????????????????????????????????? .osC? o.i5Mn0.375 io.375) 02 (III). These and other aspects of the invention will be apparent from the detailed description below. However, in no case should the foregoing be construed as limitations on the subject matter claimed, such subject matter being defined only by the appended claims, as they may be amended during the prosecution. BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a triangular pyramidal graph showing a variety of lithium transition metal oxide compositions. Figure 2 is a triangular graph showing certain lithium transition metal oxide compositions of Figure 1.

Figure 3 is an exploded perspective view of an electrochemical cell. Similar reference symbols in the various figures indicate similar elements. The elements in the figures are not to scale. DETAILED DESCRIPTION OF THE INVENTION The described lithium-transition metal oxide compounds have particular utility for making lithium ion battery cathodes. The compounds are formed by wet grinding together the oxides or oxide precursors containing cobalt, manganese, nickel and lithium, while imparting sufficient energy to the ground ingredients to form them into a finely divided suspension containing cobalt, manganese , nickel and lithium well distributed. The oxides or oxide precursors do not need to be mixed together at the same time. It has been found that by first grinding together the materials of lower surface area or larger particle diameter to increase their surface area or to reduce their particle size for. that corresponds to the surface area or the particle size of the components added later, a more homogeneous and finely divided final mixture can be produced using a shorter grinding time. Components of very high surface area (such as hydroxides) that can agglomerate in a grinding vessel can be mixed more homogeneously with other components that have already been ground to a similar elevated surface area. A finely divided, homogeneous, finely divided mixture can help promote the formation of a single-phase burned product. For example, in a milling scheme that could be referred to as "manganese and nickel first, lithium at the end", the oxides or oxide precursors containing manganese and nickel can be wet milled together and finely formed first divided containing well-distributed manganese and nickel, followed by the addition of an oxide or oxide precursor, containing cobalt to form a finely divided second suspension containing well-distributed cobalt, manganese and nickel, followed by the addition of an oxide or precursor of oxide containing lithium to form a finely divided third suspension containing cobalt, manganese, nickel and lithium well distributed. A grinding scheme that could be described as "cobalt, manganese and nickel first, lithium at the end", can be used to promote the formation of a suspension containing cobalt, manganese and nickel well distributed prior to the addition of the lithium. Grinding schemes such as "manganese and nickel first, cobalt and lithium at the end", "manganese and nickel first, cobalt at the end" (with the - lithium that is added after manganese and nickel and before cobalt), of "nickel and cobalt first, of manganese and lithium at the end", of "lithium and cobalt first, manganese and nickel at the end" and other permutations that will be evident to those skilled in the art, can also be employed. Oxides or oxide precursors containing cobalt, manganese, and nickel, suitable, include cobalt hydroxide (Co (OH) 2), cobalt oxides (e.g., Co304 and CoO), manganese carbonate (Mn2C03), manganese (MnO), manganese tetroxide (Mn304), manganese hydroxide (Mn (OH) 2), basic manganese carbonate (Mn2C03 * xMn (OH) 2) / nickel carbonate (Ni2C03), nickel hydroxide (Ni ( OH) 2), and basic nickel carbonate (Ni2C03 * xNi (OH) 2). Preferably at least one of the manganese or nickel precursors is a carbonate. Suitable oxide precursors and oxides containing lithium include lithium carbonate (Li2C03) and lithium hydroxide (LiOH). If desired, the hydrates of the precursors can be used. The amounts of each oxide or oxide precursor are typically selected based on the composition of a target final compound. A wide variety of the final target compounds can be prepared. The graphs shown in Figure 1 and Figure 2 can help you select an objective. Figure 1 is a triangular pyramidal graph whose vertices A, B, C, and D respectively represent the compositions of LiCo02, LiMn02, LiNi02 and Li (Li? / 3Mn2 / 3) 02. The vertices A, B and C thus represent respectively the maximum contents of cobalt, manganese, and nickel for the binary, lithium transition metal oxide compounds containing these transition metals at the indicated stoichiometry. The point E located in the middle part along the edge BC represents the composition of LiMn1 / 2Ni1 / 202. The points within the graph located above the base ABC represent lithium intercalation compounds. Figure 2 is a triangular graph representing the plane defined by points A, D and E. The trapezoidal region AEFG in Figure 2 (but excluding the nearest points, for example, within approximately 0.01 units per mole of metal of transition, up to vertices A and D) illustrates a particularly preferred set of compositions containing equimolar amounts of manganese and nickel. This preferred set of compositions can be represented by the formula Lia [Coz (Ni? / 2Mn? / 2) l-x] 02, where 0 <; a < 1.2 and 0.1 < x < 0.98. The compounds of formulas I, II and III are shown as points within the AEFG region. A variety of wet milling techniques can be employed including milling media (eg, ball milling, crushing milling, horizontal milling or vertical milling), milling without means (eg, hammer milling, milling by means of a jet or high pressure dispersion grinding) and other techniques that will adequately pulverize and co-mix oxides and oxide precursors containing cobalt, manganese and nickel. When grinding with media is employed, suitable means include ceramic means (e.g. ceramic bars or balls). Water is a preferred wet milling liquid but other substances such as low boiling alcohols, toluene and acetone can be employed if desired. Ball milling must be carried out for a sufficient time and with sufficient vigor so that the final suspension contains cobalt, manganese, nickel and lithium well distributed. Preferably, the suspension is ground to-that. it contains relatively small particles, for example, with an average particle diameter of less than about 0.3 μm, preferably less than about 0.1 μm as measured using imaging in an electron-scanning microscope (SEM). The perfectly uniform distribution of metals from start to finish of the suspension and the minimum average particle diameters are not required. However, particles of a single, given metallic component, greater than 0.5 μm are preferably avoided. The extent to which grinding is carried out will only need to be sufficient to provide the desired single-phase lithium transition metal oxide compound at the end of the heating step. The appropriate mixing times (and when used, the media) will typically depend in part on factors such as the raw materials and the mixing equipment employed. Frequently some experimentation measure will help a given production adjustment for Determine the appropriate grinding times or media so that the desired single-phase lithium transition metal oxide compound can be obtained. If desired, other oxides or precursors of transition metal oxides may be included in the compositions of lithium transition metal oxide before they are burned to provide the final lithium transition metal oxide compounds. Representative examples include iron, vanadium, aluminum, copper, zinc, zirconium, molybdenum, niobium, and combinations of . same. These and other oxides and precursors of transition metal oxides can be added together with the other ingredients used to form the suspension or after the suspension has been formed. The suspension is converted to an oxide compound of lithium-transition metal by the separation of the suspension and the medium (if used) and by burning, baking, sintering or otherwise heating the suspension for a sufficient time and at temperatures sufficient to form the compound of a single desired phase. The heating cycle preferably employs a rapid heating rate, for example, 10 or more ° C per hour. A preferred heating cycle is at least 10 ° C / minute at a temperature of at least 900 ° C. Air is a preferred heating atmosphere but other gases such as oxygen or mixtures of carbon dioxide, carbon monoxide, and hydrogen, may be employed if desired. If temperatures above about 1050 ° C are employed, then a ceramic furnace and longer cooling times may be required. Such higher temperatures can help to obtain a single-phase lithium transition metal oxide compound but can also increase capital costs and reduce throughput. If temperatures as high as 1100 ° C are employed, then lithium-ion batteries made using the lithium-transition metal oxide compound may exhibit a slight increase in the loss of capacity of the irreversible first cycle. Preferably, the maximum heating temperature is less than 1050 ° C, more preferably lower, than 1000 ° C, and even more preferably not greater than 900 ° C.

The resulting lithium transition metal oxide compound is preferably formed, or converted to, finely divided particles having the desired average particle diameter. For example, the lithium transition metal oxide compound can be prepared using a feedback mechanism in which the oxide is burned using a rotary calciner or other suitable burn device and sized by size so that larger particles than the desired ones are additionally wet-milled (or if desired, ground-proof), and the particles that are smaller than desired are further burned in the calciner. In this way, an adequate particle size distribution can be obtained. The lithium transition metal oxide compound can be used only at the cathode or as a cathodic additive in combination with other cathode materials such as lithium oxides, sulfides, halides, and the like. For example, the lithium transition metal oxide compound can be combined with conventional cathode materials such as cobalt and lithium dioxide or with compounds such as LiMn204 and LiFeP04 spinels. The amount of another material of the cathode to be added is selected such that the number of moles of lithium available from the other cathode material equals the number of moles of lithium irreversibly consumed by the anode. The number of moles of lithium consumed irreversibly, in turn, is a function of the properties of the individual anode. The cathode can be combined with an anode and an electrolyte to form a lithium-ion battery. Examples of suitable anodes include a lithium metal, graphite, hard coal, and lithium alloy compositions, for example, of the type described in U.S. Pat. No. 6,203,944 (Turner '944) entitled "ELECTRODE FOR A LITHIUM BATTERY" and PCT published patent application No. WO 00103444 (Turner PCT) entitled "ELECTRODE, MATERIAL AND COMPOSITIONS". The electrolyte can be liquid, solid or a gel. Examples of the solid electrolytes include polymer electrolytes such as polyethylene oxide, polytetrafluoroethylene, fluorine-containing copolymers, and combinations thereof. Examples of the liquid electrolytes include ethylene carbonate, diethyl carbonate, propylene carbonate, and combinations thereof. The electrolyte is typically provided with a lithium electrolyte salt. Examples of suitable salts include LiPF6, LiBF4, and LiCl04. Preferably the capacity of the battery is not substantially reduced after the battery is charged and discharged at between 4.4 and 2.5 volts for at least 100 cycles at a discharge rate of 75 mA / g. The invention is further illustrated in the following illustrative examples, in which all parts and percentages are by weight unless otherwise indicated. Examples X-ray diffraction A X-ray powder diffraction (XRD) configuration for each sample was collected using a Siemens D500 diffractometer equipped with a copper objective X-ray tube and a diffracted beam monochromator. The samples were prepared as flat rectangular powder beds, sufficiently thick and wide, so that the volume of dust illuminated by the X-ray beam was constant. The data was analyzed using the GSAS version of the. Rietveld refinement program as described in A. C. Larson and R. B. Von Dreele, "General Structure Analysis System (GSAS)", Los Alamos National Laboratory Report LAUR 86-748 (2000). Two statistics Rp, and Chi2 calculated by the GSAS program were used to determine the quality of the adjustment (expressed as the residual error on the fit for the case of Rp and as the goodness of fit for the case of Chi2) for a model of the structure of the single phase crystal, proposed for the data. The lower the value for Rp, the better the model fits for the data. The closer Chi2 is to the unit. { 1,000), the better the model fits the data. Rp and Chi2 are generally higher when they are not taken into account for the phase or phases that are present. The constants of the reticular structure or the dimensions of the unit cell were also calculated using the GSAS program. Preparation of the electrochemical cell The powders were formulated by combining 2.0 parts of the oxide powder, 2.3 parts of the N-methyl pyrrolidinone, 1.1 parts of a 10% by weight solution of polyvinylidene fluoride KINAR ™ 461 (available from Elf Atochem). in N-methyl pyrrolidinone, and 0.11 parts of SUPER-P ™ conductive carbon (available from MMM Coal, Belgium). The suspension was stirred at high shear for a period greater than one hour, then coated on an aluminum foil with a notched bar to provide a coating of 5% conductive carbon, 5% polyvinylidene fluoride, 90% active. The coating was dried under vacuum at 150 ° C for 4 hours, then converted into 2325 button-type batteries (half-cells) using a Li-sheet anode of 17 mm diameter, 380 micrometer thick, metallic, 2 coats of a 50 micron thick CELLGARD ™ 2400 separator (commercially available from Hoechst-Celanese), and 1 molal LiPF6 in a 1: 2 mixture by volume of ethylene carbonate and diethyl carbonate as the electrolyte.

An exploded perspective view of the electrochemical cell 10 used to evaluate the cathodes is shown in Figure 3. A stainless steel lid 24 and a special oxidation-resistant case 26 contain the cell and serve as the negative and positive respectively. The cathode 12 was prepared as described above. The lithium plate anode 14 also functioned as a reference electrode. The hardware of 2325 button-type batteries characterized as cells, equipped with an aluminum spacer plate 16 behind the cathode and a copper 18 spacer plate behind the anode. The spacers 16 and 18 were selected so that a tightly compressed stack could be formed when the cell was closed by corrugation. The separator 20 was moistened with a 1M solution of LiPF dissolved in a mixture of 1: 2 by volume of ethylene carbonate and diethyl carbonate. A .27 board was used as a seal and to separate the two terminals. The cells were cyclized at room temperature and at "C / 5" (5 hours charge and 5 hours discharge) at the speed using a constant current cycler machine. Example 1 The precursors containing a metal were combined in proportions to give the final oxide composition LiNio.iMino.1COo.sCO2. An exact batch distribution was achieved by evaluating the precursors. The tests were carried out by baking the aliquots of the precursors at 600 ° C overnight to give completely single phase water-free oxides. The measurements of the weights before and after the heating, combined with the knowledge of the composition of the final phase were used to calculate the mass per molecule of the metal in each precursor. This method allowed for batch distribution with at least one percentage accuracy by weight of +/- 0.1. The precursors of NiC03 (22.44 parts, available from Spectrum Chemical) and MnC03 (21.48 parts, Spectrum Chemical), were placed in a SWECO ™ 1 liter high density polyethylene grinding jar (available from SWECO) in the company of 333 zirconium oxide, cylindrical, zirconium oxide, 12.7 mm radius ZIRCOA ™ (available from Zircoa, Inc.), and 1000 parts ZIRCOA zirconium oxide medium of similar .35 mm. 200 parts of deionized water (DI) were added to the milling jar and the nickel and manganese carbonates were wet milled in a SWECO M18-5 mill (available from Sweco) for 24 hours. Li2G03 68.12 'parts, available from FMC, Philadelphia, PA), C0 (OH) 2 (137.97 parts, available from Alfa Aesar) and about 100 parts of DI water added to the milling jug, were then ground for about 4 hours. additional hours The resulting wet milled slurry was poured into a PYREX ™ baking tray (available from Corning, Inc.) and air dried overnight at 70 ° C. The dried cake was scraped off the tray, separated from the medium and pelletized through a 25 mesh screen (707 μm). The resulting sieved powder was placed in a clean polyethylene bottle and the lid was sealed with a tape. 15 parts of the sieved powder were placed in an alumina crucible and heated from room temperature to 900 ° C in oxygen for a period of one hour, kept at 900 ° C for 3 hours, and cooled. The resulting burnt powder was subjected to XRD analysis using the Rietveld refinement. The observed XRD configuration indicated that the burned powder had a single phase. The burned powder was used to form a cathode in an electrochemical cell as described above. The electrochemical cell had a capacity of 146 Ah / g. The loss of capacity of the first cycle, irreversible, was 5% after loading and unloading the cell at 4.3 volts. Example 2 15 parts of the wet mill suspension of example 1 were heated in oxygen using a "soaking up" cycle as follows. The suspension was placed in an alumina crucible and heated in an oven whose temperature was increased from room temperature to 250 ° C for 20 minutes, was maintained at 250 ° C for one hour, increased to 750 ° C for 20 minutes, maintained at 750 ° C for another hour, increased to 900 ° C for 20 minutes and maintained at 900 ° C for three hours . The burned sample was cooled in the oven overnight, then subjected to XRD analysis using the Rietveld refinement. The observed XRD configuration of LiNi0.?Mn0.?C?o.8?2 indicated that the sample had a single phase. Comparative Example 1 The powders of Co (OH) 2 (7.63 parts, available from Alfa Aeasar), NiC03 (1.27 parts, available from Spectrum Chemical) and MnC03 (1.17 parts, available from Spectrum Chemical) were combined in a milling jug. tungsten carbide having approximately a volume of 100 ml and containing a 15 mm ball and seven 6 mm balls of the Zircon grinding media similar to those used in example 2. The components were dry milled for 30 minutes. minutes on a SPEX model 8000-D double agitator mixer (available from SPEX CertiPrep Inc.). Lithium was added to the transition metal mixture in the form of Li2C03 (3.79 parts, available from FMC). After the lithium addition, an additional dry milling was carried out for 15 minutes. After grinding, the mixture was transferred to alumina crucibles and burned at a temperature of 900 ° C and maintained at this temperature for one hour. This produced a compound of the formula LiNi0.?Mno.iC?o.8?2 that was found to have at least two phases by XRD analysis. Comparative Example 2 The aqueous solutions of nickel, manganese, and cobalt nitrate were combined in a molar ratio of Ni: CO: Mn 1: 8: 1. The mixture was immersed in a turbulently stirred aqueous solution of 1.6 M LiOH, which was present in a 20% excess for the production of Nio.?Mn0.?Co0.8 (OH) 2- The resulting suspension was filtered and washed continuously in a basket centrifuge until the residual Li in the wet cake was less than 0.2 atomic percent of the metals present. The cake of the washed hydroxide material was then dried at less than 120 ° C until it became brittle and subsequently pulverized until it passed through a 500 micron sieve. This powder was analyzed to verify the content of the metals. The most Li2C03 powder was combined in a 100 ml tungsten carbide mill (available from Fritsch CmbH) in a molar ratio of Li: Ni: Co: Mn 10: 1: 8: 1. Then, ten small 5 mm balls of the Zircon milling medium, similar to those used in example 2, were added to the container. The vessel was stirred for 10 minutes in a SPEX ™ CertiPrep ™ mill / mixer (available from SPEX CertiPrep Inc.). The resulting mixture was transferred to an alumina crucible and treated with heating for • 1 hour at 480 ° C, 1 hour at 750 ° C, and finally 1 hour at 900 ° C. The resulting powder was ground in a mortar and pestle and examined by XRD using Rietveld's refinement. The observed XRD configuration indicated that the single-phase LiNio.?Mn0.???????????????????????????????????????????????????????????? This was the same product that was obtained in Example 1 and Example 2, but required longer washing and drying steps that were not necessary in Example 1 and Example 2. Various embodiments of the invention have been described.

However, it will be understood that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (19)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property. A process for manufacturing lithium oxide-transition metal compounds of a single phase containing cobalt, manganese and nickel, characterized in that it comprises: a) wet grinding oxides or precursors of cobalt, manganese, nickel and lithium oxides to form a finely divided suspension containing cobalt, manganese, nickel and lithium well distributed, and b) to heat the suspension to provide a lithium oxide-transition metal compound containing cobalt, manganese and nickel and having a crystalline structure of 03 substantially one phase.
2. 2. A process according to claim 1, characterized in that the water is used for wet milling.
3. 3. A process according to claim 1, characterized in that it comprises milling the suspension until it contains particles having a particle diameter - average less than about 0.3 μm.
4. 4. A process according to claim 1, characterized in that it comprises grinding the suspension until it contains particles having an average particle diameter of less than about 0.1 μm.
5. 5. A process according to claim 1, characterized in that it comprises grinding the powders using a ceramic medium.
6. 6. A process according to claim 1, characterized in that the precursors comprise one or more carbonates.
7. 7. A process according to claim 6, characterized in that at least one of the precursors comprises manganese carbonate or nickel. 8. A process according to claim 1, characterized in that it comprises milling together equimolar amounts of oxides or oxide precursors containing manganese and nickel. 9. A process according to claim 1, characterized in that it comprises heating the suspension at a speed of at least 10 ° C / minute at a temperature of at least 800 ° C. 10. A process according to claim 1, characterized in that it comprises heating the suspension to a temperature at or below 1050 ° C. 11. A process according to claim 1, characterized in that the lithium transition metal oxide compound is selected from those represented by the formula Lia [Cox (Ni? / 2Mn? / 2) lx] 02, wherein 0 < a < 1.2 and 0.1 < x < 0.98. 12. A process according to claim 1, characterized in that the lithium transition metal oxide compound has the approximate formula Li (Co (o.
8. 8) Mn0.?Nio.?)? 2. 13. A process according to claim 1, characterized in that the lithium-transition metal oxide compound has the approximate formula Li (Co (1/3) Mn (1/3) Ni (a 3)) 02. 14 A process according to claim 1, characterized in that the lithium transition metal oxide compound has the approximate formula Li (Li0.0sCO0.15Mn0.375Ni0.375) 02. 15. A process according to claim 1 , characterized in that it further comprises mixing the particles of the lithium-transition metal oxide compound with a conductive carbon and a binder, and coating the resulting mixture on a support substrate to form a cathode of the lithium-transition metal oxide. 16. A process according to claim 15, further comprising placing the cathode, an electrically compatible anode, a separator and an electrolyte in a vessel to form a lithium-ion battery. 17. A process according to claim 16, characterized in that the capacity of the battery is not substantially reduced after the battery is charged and discharged between 4.4 and 2.5 volts for at least 100 cycles at a discharge rate of 75 mA / g. 18. Lithium-transition metal oxide compounds having the formula: LiaC? BMnoNi? _b-c02 characterized in that 0 <. a < 1.2, 0.52 < b < 0.98, 0.01 < c < 0.47 and 0.53 < b + c < 0.99. 19. A composition of the lithium transition metal oxide, characterized in that it consists essentially of a compound selected from the group consisting of the single-phase compounds of: LiNio.1Mno.1Cdo.sO2, Li (C? (? / 3 ) Mn (i3) Ni (i / 3)) 02 and Li (Lio.osCOo.15Mno.375) 02. 20. A lithium ion battery, characterized in that it comprises at least one lithium transition metal oxide compound according to claim 18. 21. An ion battery lithium, characterized in that it comprises at least one composition of the lithium transition metal oxide according to claim 19.