New intermediates between active cathode materials and precursors

Abstract

To provide a method for forming a lithium-ion cathode material that significantly reduces cost and increases manufacturing efficiency.SOLUTION: The method includes the steps of: forming a precursor containing a lithium salt and at least one multi-carboxylate of nickel, manganese, or cobalt; heating the precursor in a metal-lined container at the temperature of 600°C or lower to form an intermediate substance; and heating the intermediate substance at the temperature exceeding 600°C to form the cathode active material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS: This application claims priority to pending U.S. Provisional Patent Application No. 63 / 189,334 (filed May 17, 2021), the contents of which are incorporated herein by reference.

[0002] Technical field of the invention The present invention relates to the formation of an intermediate material that is formed after the formation of a cathode material precursor and before calcination to form the active cathode material. More specifically, the present invention relates to a novel material that can be formed in large quantities in a metal-lined, preferably rotary, kiln, thereby reducing dependency on high temperature kilns and the ceramic kiln furniture used therein. [Background technology]

[0003] A recently developed process for forming active cathode materials is referred to in the art as the one-pot process. This method is particularly suited to forming cathode materials containing oxides of lithium, nickel, manganese, and optionally cobalt in a crystal lattice, particularly a spinel lattice, referred to in the art as NMC. The one-pot method involves the initial formation of an organic salt of lithium and the metal, referred to herein as a precursor, which is heated to a calcination temperature to form the lithium metal oxide that functions as the cathode in the battery.

[0004] Specific examples of precursor organic salts include, but are not limited to, multicarboxylates, oxalates, etc. The formation of such active cathode materials utilizing precursors is described in commonly assigned U.S. Patent Publications: U.S. Patent Application No. 2019 / 0372120 published December 5, 2019; U.S. Patent Application No. 2020 / 0373560, published November 26, 2020; and Patent application No. 2021 / 00028448 published on January 28, 2021. These are incorporated herein by reference in their entirety.

[0005] During calcination, the precursor loses 50-66% of its mass by weight, with the losses being primarily CO2 and water, which displace the kiln atmosphere, which controls the oxygen partial pressure throughout the bulk of the powder, making it difficult to control.

[0006] Regardless of origin, yet another problem associated with precursors is their reliance on high-temperature furnaces and kiln furniture for use within the furnaces. Kiln furniture, such as saggers, are typically fabricated from ceramic materials that must be replaced frequently. Ceramic is necessary because the typical process for cathode fabrication involves using lithium hydroxide as the lithium source. Lithium hydroxide melts early in the heating process, and molten lithium hydroxide is highly corrosive. Molten lithium hydroxide also precludes the use of any type of rotary kiln, as the molten lithium hydroxide coats and deteriorates the kiln surfaces. Therefore, the process is limited to a relatively low-volume, stagnant heating process using ceramic saggers.

[0007] The present invention provides for the formation of an intermediate material formed between a precursor and a calcined oxide, where the intermediate material is formed in bulk, in contact with a metal, and isolated or transferred directly to a kiln for calcination. The present invention eliminates many of the problems associated with calcining precursors to form active cathodes for use in lithium ion batteries. Summary of the Invention

[0008] The present invention relates to an improved method for forming lithium ion cathode materials, particularly lithium ion cathode materials comprising lithium metal oxides containing nickel, manganese, and optionally cobalt.

[0009] A feature of the present invention relates particularly to the ability to form intermediate materials from precursors, which can be formed in contact with metals, thereby significantly reducing costs and increasing manufacturing efficiency.

[0010] Another particular feature is the ability to form the intermediate material in bulk from the precursor by tumbling or stirring, resulting in a fine powder that can be isolated or passed directly to a kiln for further heating to mineralization.

[0011] A particular advantage of the present invention is the ability to form calcined cathode material from an intermediate material that is already lithiated, reducing the volume of material added to the kiln and the time required to calcine the intermediate material, thereby reducing the time at calcination temperatures, increasing manufacturing efficiency, and improving the capital cost per volume of calcined material produced.

[0012] Yet another particular advantage is the elimination of liquid lithium hydroxide, which increases the useful life of the kiln tools.

[0013] These and other advantages may be realized in a process for forming an active cathode material that includes: forming a precursor comprising a lithium salt and at least one multicarboxylate salt of nickel, manganese, or cobalt; heating the precursor in a metal-lined vessel to a temperature of 600°C or less to form an intermediate material; and heating the intermediate material to a temperature of 600° C. or greater to form the active cathode material.

[0014] Yet another embodiment provides a process for forming an active cathode material comprising: forming a precursor comprising a lithium salt and at least one multicarboxylate salt of nickel, manganese, or cobalt; heating the precursor in a first vessel to a temperature of 600°C or less to form an intermediate material; transferring the intermediate material to a second container; and and heating the intermediate material in the second container to a temperature greater than 600° C. to form the active cathode material.

[0015] Yet another embodiment is a method of forming an active cathode material comprising: forming a precursor comprising lithium oxalate and at least one multicarboxylate of nickel, manganese, or cobalt; heating the precursor to a temperature of 600°C or less in a rotary kiln vessel to form an intermediate material; and heating the intermediate material to a temperature greater than 600° C. to form the active cathode material.

[0016] Yet another embodiment provides an intermediate material to the active cathode material having a formula selected from the group consisting of: LiNi x Mn y Co z E w O4 Formula I where E is an optional dopant; and x+y+z+w = 2 and w≦0.2 and LiNi a Mn b X c G d O2 formula II where G is an optional dopant; X is Co or Al; and wherein a+b+c+d=1 and d≦0.1; and The intermediate material is at least 7 m 2 / g of surface area. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a graphical representation illustrating the advantages of the present invention.

[0018] [Figure 2] FIG. 2 is a graphical representation illustrating the advantages of the present invention.

[0019] [Figure 3] FIG. 3 is a graphical representation illustrating the advantages of the present invention.

[0020] [Figure 4] FIG. 4 is a flow chart representation of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention relates to an improved method for forming an active cathode material and to the formation of an intermediate material that can be formed in contact with a metal. More specifically, the present invention relates to a method for forming an intermediate material into an active cathode material, which can be formed in high volume in contact with a metal at lower temperatures, and the precursor can be subjected to a rotating action or stirring during heating to form the intermediate material.

[0022] Precursors to active cathode materials formed using multicarboxylates, such as oxalic acid, evolve CO2 and water during heating. Surprisingly, it has been discovered that pre-calcining the precursor in air or oxygen at temperatures between 200°C and 600°C decomposes organic salts, such as, but not limited to, oxalates, into preferred lithiated mixed metal oxides. Particular advantages are realized by incorporating lithium organic salts, such as, but not limited to, lithium oxalate, which directly form lithium oxide without forming a liquid phase. The combination of lower temperatures and removal of the lithium-containing liquid phase allows the initial heating step, up to about 600°C, to be carried out in the presence of metal, and heating can be carried out with rotation or stirring, thereby resulting in an intermediate material that is a free-flowing powder. Particularly preferred lithium salts include monocarboxylates and multicarboxylates, with lithium acetate and lithium oxalate being exemplary.

[0023] After formation of the intermediate material, the intermediate material powder can be calcined at temperatures between 700°C and 925°C in a more controlled atmosphere below about 600°C to form the final active cathode material. A particular advantage provided by the present invention is that the intermediate material has a stoichiometry close to that of the final cathode material. During the second calcination to form the active cathode material from the intermediate material, the release of volatile components is minimal, which optimizes kiln utilization.

[0024] The intermediate material has less than 10 wt% carbon, more preferably 9 wt% or less, more preferably 8 wt% or less, more preferably 7 wt% or less, more preferably 6 wt% or less, more preferably 5 wt% or less, more preferably 4.5 wt% or less, even more preferably 4 wt% or less, even more preferably 3 wt% or less, even more preferably 2 wt% or less, even more preferably 1 wt% or less, even more preferably 0.5 wt% or less, even more preferably 0.4 wt% or less, and most preferably no detectable carbon, as determined by ASTM E1019-11.

[0025] The present invention will now be described with reference to the drawings, which constitute an essential but non-limiting component of the disclosure of the present invention.

[0026] An embodiment of the present invention will now be described with reference to Figure 4, which is shown in a flow chart representation. In Figure 4, a precursor is formed at 10 (Figure 4), the precursor comprising a salt of a metal and a multicarboxylic acid, the metal comprising nickel, manganese, and optionally cobalt. The precursor also comprises a lithium multicarboxylic acid salt or lithium carbonate, with lithium oxalate being preferred.

[0027] The precursor is heated in the first vessel to a temperature of 12°C to 600°C or less, where the precursor preferably contacts a metal during heating. In one embodiment, the surface of the first vessel that contacts the precursor consists of or is formed from a metal. The metal is not particularly limited herein, and any metal currently utilized to form kiln linings or metal saggers is suitable for demonstrating the present invention. Particularly suitable for demonstrating the present invention are nickel-based alloys such as Inconel® alloys, including, but not limited to, Inconel® 601, Inconel® HX, and Inconel® MA956. In a particularly preferred environment, the vessel is a metal-lined (also called lining) furnace, with metal-lined rotary furnaces being particularly preferred. Without being limited by theory, it is hypothesized that rotation or agitation of the precursor during calcination improves the reaction because CO and water evolution from the interior portions of the powder is more efficient and the formation of a kinetically favorable crystal lattice (which is ultimately the same as the active cathode material) can be more easily formed because powder movement minimizes the need for metal movement to achieve the desired crystal lattice. After heating the precursor in the first vessel for a sufficient time, an intermediate material is obtained.

[0028] The intermediate material is optionally, but preferably, transferred to a second vessel for subsequent heating at 14 (FIG. 4). Metal-lined vessels are less desirable for heating the intermediate material to the extent necessary to form the active cathode components. The intermediate material is heated to a preferred temperature of about 700°C to 925°C for a time sufficient to form the active cathode material at 16 (FIG. 4). Without being limited by theory, it is hypothesized that the use of some form of agitation during the initial heating in the first vessel causes the lithium and metal to form the desired crystalline structure for the active cathode material, and therefore the second heating in the second vessel serves to increase the size of the crystals. Because the crystals are already lithiated in the first heating in the first vessel, the prior art method of heating long enough for the lithium to migrate into the lattice is not necessary. After the second heating, the active cathode material is obtained in the second vessel at 18 (FIG. 4), and the cathode is formed at 20 (FIG. 4).

[0029] As will be appreciated, prior art processes utilizing lithium hydroxide cannot be heated in metal due to melting of the lithium hydroxide, which is corrosive to the metal and forms agglomerated powder. For purposes of the present invention, the precursor has less than 5 wt.% lithium hydroxide, more preferably less than 4 wt.% lithium hydroxide, even more preferably less than 1 wt.% lithium hydroxide, even more preferably less than 0.1 wt.% lithium hydroxide, and most preferably no detectable lithium hydroxide.

[0030] Metal salts of multicarboxylic acids can be formed by digesting digestible metal salts, such as metal carbonates, or by direct reaction of the elemental metal with the multicarboxylic acid. The multicarboxylic acid contains at least two carboxyl groups. A particularly preferred multicarboxylic acid is oxalic acid, in part due to minimizing the carbon that must be removed during calcination. Other low molecular weight dicarboxylic acids, such as malonic acid, succinic acid, glutaric acid, and adipic acid, can be used. Higher molecular weight dicarboxylic acids can also be used. Dicarboxylic acids with even numbers of carbons are particularly preferred due to their higher solubility, but the need to remove additional carbons and reduced solubility make them less desirable. Other acids, such as citric acid, lactic acid, oxaloacetic acid, fumaric acid, maleic acid, and other polycarboxylic acids, can be used, provided they achieve at least a small stoichiometric excess and are sufficiently soluble to have sufficient chelating properties. It is preferred to avoid acids with hydroxyl groups due to their high hygroscopicity.

[0031] A particular feature of the present invention is the formation of a pre-lithiated salt as an intermediate prior to the mineralization process. The precursor lithium salt, for example, lithium oxalate, forms lithium oxide directly in the presence of the metal without forming a liquid phase. Thus, lithium is incorporated into the metal salt prior to calcination, improving the efficiency of lithium incorporation.

[0032] A particular advantage of the present invention is that the intermediate material is preferably formed in a metal container while rotating or stirring the first container. In a particularly preferred method, an organic salt precursor can be heated in a rotary kiln as the first container using a high-temperature steel tube to produce a uniform, free-flowing powder. Because the precursor can be rotated or stirred, a larger amount of material can be heated compared to conventional methods involving a kiln and relatively static powders. This is possible because the one-pot process forms lithium oxide directly from an organometallic salt, such as lithium oxalate, which is preferable to adding LiOH in the precursor. When LiOH is used in the precursor, it generally melts at the pre-calcination temperature, adhering the reactants to the inner surface of the tube. Using any kiln with heating and stirring, such as a rotary kiln, allows the intermediate material to be mixed while heating and produce a homogeneous material. In contrast, static calcination generally results in a range of compositions from top to bottom within the sagger.

[0033] The one-pot process intimately mixes all reactants together, where the lithium salt is extremely finely distributed throughout the precursor. This is an improvement over the traditional method of adding LiOH as a co-mixed fine powder. Without being limited by theory, it is hypothesized that the organic salt forms the desired lithiated crystal structure during initial heating. Based on that, the intermediate material, while not fully formed into the final active material, has already formed the correct crystal structure, thus allowing for the incorporation of Li into the oxide lattice structure. +It is assumed that the oxide lattice structure is already lithiated at this temperature. Formation of the desired crystal structure occurs as low as 200°C and is complete by 600°C. Prior art has hypothesized that the oxide lattice structure does not form at such low temperatures because lithium cannot be significantly incorporated into the lattice and therefore the desired crystal structure cannot be formed. Therefore, the material added to the sagger for the final calcination / crystallization calcination and calcination time is already stoichiometric with minimal or no further loss of material, which is expected to improve kiln utilization. Reducing the time at calcination temperature is particularly important when forming products in O2, such as high-Ni NMC. It is easier to maintain the desired O2 partial pressure in the calcination kiln during the final high-temperature calcination, as CO2 or water evolution is significantly reduced, and theoretically neither is reduced.

[0034] The intermediate comprises the desired crystalline structure, as described elsewhere. [ka] It is particularly preferred that the space group contains at least 50% by weight of material having a crystalline structure. More preferably, the intermediate material contains at least 75% by weight of R3m or [ka] Even more preferably, the intermediate material comprises at least 90% by weight of a material having a crystalline structure within a space group R3m or [ka] Most preferably, the intermediate material is at least 99% by weight of R3m or [ka] Includes materials with crystalline structure in space group.

[0035] The surface area of ​​the intermediate material is 7m 2 / g, and preferably exceeds 9m 2 / g, and more preferably 10m 2 More preferably, it is greater than 45m 2 / g. Once the proper crystal lattice is achieved and the precursors are removed, further heating increases the crystallinity and decreases the surface area. Fully sintered material typically has a surface area of ​​about 2 m 2 / g。 However, while it is theoretically possible to achieve complete sintering at lower temperatures, the time required to achieve it is impractical. Therefore, it is preferable to achieve an intermediate material with high purity and high surface area for subsequent sintering in a separate step. In prior art processes, fully lithiated material crystallized with the desired space group symmetry could not be achieved with such a high surface area because the surface area is dramatically reduced during lithiation of the pre-fired material.

[0036] Because the intermediate material is already in the proper crystal lattice, it is hypothesized that a second heating to the calcination temperature in a second vessel increases the crystallinity with a concomitant decrease in surface area. Lithium migration into the lattice has already occurred, and presumably the time required at the calcination temperature is significantly reduced compared to conventional methods. This results in the ability to load the intermediate material, which is already near stoichiometric, into a second vessel, such as a sagger, optimizing sagger and kiln use and optimizing kiln utilization.

[0037] Because the intermediate material is a free-flowing powder, the types of kilns suitable for use in firing exceed those currently considered appropriate. Therefore, the kiln type can be selected based on the scale of operation. Kilns utilizing interchangeable saggers include, but are not limited to, muffle kilns, roller hearth kilns, or pusher kilns, which are preferred in part due to their large installed base. Rotary kilns are particularly preferred for forming the intermediate material due to their higher throughput and cost compared to the use of saggers in kilns.

[0038] At lower temperatures, about 200-400°C, a fluidized bed can achieve the same effect of oxidation and mixing. These systems are expensive and not efficient in their use of energy.

[0039] Particularly preferred active cathode materials are is a spinel crystal structure defined by Formula I: LiNi x Mn y Co z E w O4 Formula I wherein E is an optional dopant; x+y+z+w = 2 and w≦0.2; or The rock salt crystal structure defined by Formula II; LiNi a Mn b X c G d O2 Formula II wherein G is an optional dopant; X is Co or Al; a+b+c+d = 1, d ≤ 0.1.

[0040] In a preferred embodiment, the spinel crystal structure of Formula I has 0.45≦x≦0.60; 1.40≦y≦1.50, and z≦0.90. More preferably, 0.45≦x≦0.55, 1.45≦y≦1.50, and z≦0.05. In a preferred embodiment, neither x nor y is zero. In Formula I, it is preferred that the Mn / Ni ratio is 3.00 or less, preferably at least 2.33 but less than 3, and most preferably at least 2.60 but less than 3.00.

[0041] In a preferred embodiment, the rock salt crystal structure of Formula II is a high-nickel NMC, where 0.50≦a≦0.96, more preferably 0.50≦a≦0.94, even more preferably 0.50≦a≦0.92, and even more preferably 0.58≦a≦0.62, as represented by NMC 622, or 0.78≦a≦0.82, as represented by NMC 811. In a preferred embodiment, a=b=c, as represented by NMC 111. The term NMCxxx is a shorthand used in the art to represent the nominal relative ratios of nickel, manganese, and cobalt. NMC811 is, for example, a high-nickel NMC, where a=b=c. 0.8 Mn 0.1 Co 0.1 Represents O2.

[0042] In formulas throughout this specification, lithium is defined as stoichiometrically charge-balanced, with the understanding that lithium is transferable between the anode and cathode. Thus, at any given time, the cathode may be relatively lithium-rich or relatively lithium-deficient. A lithium-deficient cathode will have lithium below stoichiometric balance, and upon charging, lithium may exceed stoichiometric balance. Similarly, in the formulations listed throughout this specification, the metals are expressed as charge-balanced, with the understanding that the metals may be slightly rich or slightly depleted, as determined by elemental analysis, since a perfectly balanced stoichiometry cannot be achieved in practice.

[0043] Dopants can be added to improve oxide properties such as electronic conductivity and stability. The dopants are preferably substitutional dopants added in concert with the primary nickel, manganese, and optionally cobalt or aluminum. The dopants preferably comprise no more than 10 mol % of the oxide, preferably no more than 5 mol %. Preferred dopants include Al, Gd, Ti, Zr, Mg, Ca, Sr, Ba, Mg, Cr, Cu, Fe, Zn, V, Bi, Nb, and B, with Al and Gd being particularly preferred. Dopants and coating materials can be added as known in the art. [Example]

[0044] Lithium nickel metal oxide in spinel crystal structure LNMO was prepared using precursor materials containing lithium, nickel, and manganese oxalates. In the inventive example, the precursor materials were heated in a rotary kiln at 500°C. In the comparative example, the same precursor materials were heated in a sagger at the same temperature. X-ray diffraction (XRD) patterns of the intermediate material heated to 925°C and the final calcined product showed a lithiated spinel crystal structure with no signs of impurities. For the intermediate material, the peaks are broader, suggesting very small crystals. The peaks grow and sharpen after calcination. The XRD patterns of the intermediate material are shown in Figure 1. In Figure 1, Scan A shows the XRD pattern of the intermediate material calcined in a sagger at 500°C for 5 hours, Scan B shows the XRD pattern of the intermediate material calcined in a rotary kiln at 500°C for 5 hours, and Scan C shows the XRD pattern of the fully calcined LNMO product after calcination at 925°C. As can be seen, the XRD shows that the intermediate material and the final calcined LNMO have the same crystal lattice.

[0045] It is clear that pure, single-phase lithiated LNMO forms at approximately 500°C. Figure 2 shows that the same phase forms even after 1 hour at 350°C, suggesting rapid and complete lithiation at this low temperature. After the final high-temperature calcination, the peaks become much sharper as the crystals grow. In Figure 2, scans A, B, and C are XRD patterns of LNMO after pre-calcination at 350°C for 1, 3, and 5 hours, respectively, and scans D, E, and F are of LNMO after pre-calcination at 500°C for 1, 3, and 5 hours, respectively.

[0046] As will be appreciated, LNMO initially has a low surface area, which decreases with subsequent sintering. A typical LNMO pre-fired at 350°C that is fully lithiated as described above has a surface area of ​​about 38m 2 / g, and after sintering at 925°C for 15 hours, the same sample had a surface area of ​​approximately 1.1 m 2 A similar representative example, LNMO, pre-calcined at 500°C for 5 hours has a surface area of ​​about 14 m 2 / g, and after sintering at 925°C for 15 hours, the same sample had a surface area of ​​approximately 0.8 m 2 / g of surface area.

[0047] Nominally LiNi 0.8 Mn 0.1 Co 0.1 The formation of NMC 811 with O2 was compared with final calcination in oxygen. In Figure 3, the XRD patterns of the powder precursor, pre-calcined intermediate material, and final NMC 811 are provided in scans a, b, and c, respectively. The pre-calcined material shows some of the major NMC peaks formed along with traces of Li2CO3 peaks as an impurity. This suggests that lithiation is initiated even at high nickel contents. The pre-calcined intermediate material exhibited approximately 23–26 m 2 / g. The final high-temperature firing yields a surface area of ​​approximately 0.3 to 0.5 m 2 This produces pure single-phase NMC 811 with a surface area of ​​1 / g.

[0048] The precursor can be pre-calcined in a rotary kiln with a high-temperature steel tube to produce a uniform, free-flowing intermediate powder. This advantage is provided by a one-pot process in which a Li feedstock, such as Li2CO3 or LiOH, is converted to lithium oxalate to form the intermediate material before initial calcination, which differs from conventional methods that present LiOH for calcination. While lithium oxalate decomposes to lithium oxide or lithium carbonate at low temperatures, LiOH generally melts at the pre-calcination temperature, depositing all of it onto the inner surface of the tube.

[0049] The present invention offers significant advantages as it allows for the use of rotary kilns or stirred processes where lithium oxalate can be calcined instead of lithium carbonate or lithium hydroxide and the kiln surfaces in contact with the material being heated can be metallic instead of ceramic, which offers significant advantages in terms of efficiency and cost.

[0050] While the present invention has been described with reference to preferred embodiments, it is not limited thereto. Those skilled in the art will recognize additional embodiments that are set forth and described in the claims appended hereto.

Claims

1. forming a precursor comprising a lithium salt and at least one multicarboxylate salt of nickel, manganese, or cobalt, wherein the lithium salt is both a lithium organic salt and a lithium carboxylate salt; heating the precursor to a temperature of 600°C or less in a metal lined vessel to form an intermediate material; and heating the intermediate material to a temperature greater than 600° C. to form an active cathode material.

2. 10. The method of forming an active cathode material of claim 1, wherein the lithium salt is a lithium multicarboxylate salt, or the lithium salt is lithium acetate or lithium oxalate.

3. 10. The method of forming an active cathode material of claim 1, wherein the precursor comprises at least one salt selected from the group consisting of nickel oxalate, manganese oxalate, and cobalt oxalate.

4. 2. The method of claim 1, wherein the metal-lined vessel is a rotary kiln, or a rotary kiln containing a nickel alloy, or a metal-lined kiln, or a metal-lined kiln that is a rotary kiln, or a metal-lined kiln that is a rotary kiln containing a nickel alloy.

5. 10. The method of forming an active cathode material of claim 1, wherein the active cathode material is selected from the group consisting of: LiNi x Mn y Co z E w O 4 Formula I where E is an optional dopant, and x+y+z+w=2 and w≦0.2; and LiNi a Mn b X c G d O 2 Formula II where G is an optional dopant. X is Co or Al, and a+b+c+d=1 and d≦0.

1.

6. 6. The method for forming an active cathode material of claim 5, wherein, in Formula I, 0.45≦x≦0.60, 1.40≦y≦1.50, and z≦0.90; or 0.45≦x≦0.55, 1.45≦y≦1.50, and z≦0.

05.

7. 7. The method of forming an active cathode material of claim 6, wherein in Formula I, neither x nor y is zero.

8. 6. The method for forming an active cathode material according to claim 5, wherein in Formula I, the Mn / Ni ratio is 3.00 or less, or the Mn / Ni ratio is at least 2.33 and less than 3.00, or the Mn / Ni ratio is at least 2.60 and less than 3.

00.

9. 6. The method for forming an active cathode material according to claim 5, wherein in Formula II, 0.50≦a≦0.96, or 0.50≦a≦0.94, or 0.58≦a≦0.62, or 0.78≦a≦0.

82.

10. 6. The method of forming an active cathode material of claim 5, wherein E or G is selected from the group consisting of Al, Gd, Ti, Zr, Mg, Ca, Sr, Ba, Mg, Cr, Cu, Fe, Zn, V, Bi, Nb, and B, or wherein E or G is selected from the group consisting of Al and Gd.

11. 10. The method of forming an active cathode material of claim 1, further comprising the step of transferring the intermediate material to a second container after heating to 600[deg.] C. or less.

12. 10. The method of forming an active cathode material of claim 1, wherein the precursor contains less than 5% by weight of lithium hydroxide or no lithium hydroxide.

13. at least 50%, 95%, or 99% by weight of said intermediate material 【Chemistry 1】 have a crystalline structure in a space group, or 【Chemistry 2】 10. The method of forming the active cathode material of claim 1 having a crystal structure in the space group:

14. The intermediate material is 7 m 2 / g or more than 9 m 2 / g or more than 10 m 2 10. The method of forming the active cathode material of claim 1, wherein the active cathode material has a surface area of ​​greater than 1000 W / g.

15. 10. The method of claim 1, wherein the step of heating the intermediate material is at a temperature of at least 700°C and not more than 900°C.

16. 10. The method of forming an active cathode material of claim 1, wherein the intermediate material has less than 0.4% by weight carbon.

17. 10. The method of forming an active cathode material of claim 1, wherein said heating of said precursor is carried out in an atmosphere comprising oxygen.

18. 10. The method of forming an active cathode material of claim 1, further comprising forming the precursor by reaction of at least one carbonate of nickel, manganese, or cobalt with a dicarboxylic acid; or further comprising forming the precursor by reaction of at least one carbonate of nickel, manganese, or cobalt with oxalic acid; or further comprising forming the precursor by reaction of at least one of elemental nickel, manganese, or cobalt with a dicarboxylic acid; or further comprising forming the precursor by reaction of at least one of elemental nickel, manganese, or cobalt with oxalic acid.

Images