Method for preparing lithium transition metal oxides from elemental metal feedstocks and products thereof

Abstract

Disclosed herein are methods for preparing lithium transition metal oxide cathode materials from elemental feedstocks for secondary battery and other applications, and the products thereof. The methods disclosed herein may include mixing at least one transition metal in elemental form with a lithium source in a dry-solid-state mixing process, followed by sintering to form the lithium transition metal oxide cathode material.

Description

[Technical Field]

[0001] The present disclosure relates to preparing lithium transition metal oxide positive electrode materials for lithium ion batteries. [Background technology]

[0002] The development of high-energy storage systems, with lithium-ion (Li-ion) batteries being the dominant technology, is a major driver for the electrification of transportation. After years of exploring various chemistries to maximize energy storage output, recent research has focused more on improving the cycle life and thermal safety of Li-ion battery cells. Also, as demand for Li-ion battery cells continues to increase, it is crucial to innovate processes to make battery materials at lower cost and with a smaller environmental footprint.

[0003] A typical secondary Li-ion battery cell includes a graphite anode, a lithium metal oxide cathode, a polymer separator, an organic electrolyte, and a casing. Among them, the lithium metal oxide cathode material is the key component in determining the energy storage capacity and battery cost. Among several types of lithium metal oxide materials, lithium nickel manganese cobalt oxide (NMC), known as "NMC," is one of the most preferred cathode materials to be used in commercial battery cells.

[0004] The most common industrial route for preparing NMC involves multiple lengthy steps. The first step typically uses a coprecipitation process to create a mixed metal hydroxide precursor (MH) essentially containing the metals Ni, Mn, and Co, and possibly a dopant A. The molar ratio of the elements is controlled in this step to achieve the desired composition. Typically, aqueous metal salts are precipitated in an NaOH solution in the presence of some chelating agent to obtain a homogeneous elemental mixture. In a later step, large amounts of water are introduced to wash the as-synthesized metal hydroxide precipitate before drying in a high-temperature furnace (typically, production of 6.5 tonnes / day of NMC generates 99,000 L of wastewater that requires treatment and storage). This step alone consumes large amounts of water and energy. The second step uses some kind of mechanical mixer to mix the metal hydroxide precursor with a lithium compound, such as LiOH or Li2CO3. The third step is calcination of the mixture in an oxygen-containing atmosphere to form the lithiated metal oxide. The fourth step uses a particle size classifier to collect the product in the desired size range. Sometimes a milling machine is used to break down agglomerates. The fifth step is a post-processing or finishing step, in which the product is washed, dried, and re-sintered at high temperature. Washing can include a surface coating step, in which the washing solution contains some chemicals that form a protective coating on the cathode surface after drying and re-sintering.

[0005] Atomic-scale mixing of transition metals (TM) could be achieved in MH precursors by using the well-known co-precipitation process. Good element mixing is crucial for achieving high-performance, single-phase NMC materials. However, the co-precipitation process generates large amounts of wastewater that must be treated to meet environmental regulations. Furthermore, soluble transition metal salts must be used as raw materials in the co-precipitation process. It is worth mentioning that insoluble transition metal compounds, such as oxides, hydroxides, carbonates, or even transition metal powders, are cheaper and more readily available. Thus, alternative methods for producing NMCs without using the co-precipitation process are important for the sustainable production of cathode materials.

[0006] Recently, several studies have presented methods for preparing NMCs and other cathode materials without using traditional methods.

[0007] The WO2021040931A1 application describes a method for preparing lithium nickel manganese cobalt oxide (NMC) microparticles using a dry solid-state process. Ni, Mn, and Co compounds selected from the group consisting of oxides, hydroxides, and carbonates are mixed with a Li source (LiO, LiOH, LiCO) by dry impact milling to form precursor microparticles before calcination. Ni, Mn, and Co in the form of metal powders are not included as raw materials.

[0008] The US8591860B2 application discloses a method for producing lithium metal oxides. A raw material mixture was prepared by mixing a lithium compound, elemental Ni or Ni compounds, other TM compounds, and a reaction accelerator made of one or more compounds selected from the group consisting of carbonates, sulfates, and chlorides of one or more elements selected from the group consisting of Na, K, Rb, Cs, Ca, Mg, Sr, and Ba. The reaction accelerator is required to improve reactivity during calcination, adjust surface area, and produce stable lithium mixed metal oxides in a calcination atmosphere containing a higher concentration of CO2 than in air. The calcination process was carried out in a gas furnace using a flame as a heat source. A mixture of combustion gas and oxygen was used to feed the gas furnace.

[0009] The CN1326232A application disclosed a method for preparing lithium manganese oxide with a spinel structure. The precursor was prepared by dissolving a mixture of Li salt and Mn source from electrolytic manganese dioxide, chemical manganese dioxide, or high-purity manganese metal in an organic acid solution (acetic acid and / or ethanedioic acid and / or oxalic acid and / or citric acid) using a wet rapid mixing method. The precursor solution was evaporated to form a gel precursor, which was then dried and calcined.

[0010] US20210359300A1 and US20220064019A1: The first application describes a "method for forming a lithium-ion metal oxide and a battery including the lithium-ion metal oxide. The method includes reacting at least one metal in elemental form with a calbox to form a metal calbox, and heating the metal calbox to form the lithium-ion metal oxide." The second application provides a "method for forming a lithium-ion cathode material. The method includes reacting an elemental metal with a polycarboxylic acid to form an oxide precursor, and heating the oxide precursor to form the lithium-ion cathode material. In a preferred embodiment, the elemental mixture includes at least two of Ni, Mn, Co, and Al." Both applications require the use of acid-based compounds, such as oxalic acid, citric acid, carboxylic acid, nitric acid, etc., to form a metal calbox complex with the metal in elemental form. The lithium metal oxide precursor slurry is dried to remove the solvent and then sintered in a furnace to form a lithium-ion metal oxide having a layered or spinel structure. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] WO2021040931A1 [Patent Document 2] US8591860B2 [Patent Document 3] CN1326232A [Patent Document 4] US20210359300A1 [Patent Document 5] US20220064019A1 Summary of the Invention [Problem to be solved by the invention]

[0012] Embodiments disclosed herein describe a method for preparing lithium transition metal oxide cathode materials from elemental metal feedstocks using a dry-solid-state mixing approach. The mixed elemental forms of the metals and a lithium source can be directly converted into lithium transition metal precursors with a wide range of stoichiometric compositions. Furthermore, a sintering process for the precursors can produce lithium transition metal oxide powders with a single phase free of lithium impurities. The embodiments disclosed herein provide a more streamlined, cost-effective, and environmentally friendly approach than traditional wet methods used to manufacture lithium transition metal oxide materials. [Means for solving the problem]

[0013] In some embodiments, the method does not require the addition of any reaction accelerators or nuclei in the mixing process: the raw metal feedstock, in elemental form, and the Li source are simply mixed and then sintered at high temperature to form a single-phase lithium transition metal oxide material with well-ordered crystallinity.

[0014] In particular, in some embodiments, the method comprises: 1+x [(Ni n Mn m Co c Al a ) 1-y A y ] 1-x 02, wherein -0.2≦x≦0.2; n+m+c+a=1; n≧0; m≧0; c≧0; a≧0; A is a metal dopant; and 0≦y≦0.05, the method being used to form a lithium transition metal oxide cathode material having a cation exchange ratio of 0.01 to 0.02, the method comprising: a) stoichiometric amounts of one or more lithium compounds, one or more elements or compounds of Ni, one or more elements or compounds of Mn, one or more elements or compounds of Co, one or more elements or compounds of Al, and / or one or more elements or compounds of formula Li 1+x [(Ni n Mn m Co c Al a ) 1-y A y ]1-x 1. Preparing a precursor mixture by combining one or more elemental metal dopants or compounds of said metal dopants with O: - at least one transition metal is in elemental form and is selected from the group consisting of Ni, Mn, and Co to form said precursor; - the compound of the remaining metal is selected from the group consisting of oxides, hydroxides, oxyhydroxides, carbonates, sulfates, nitrates, acetates, and combinations thereof; The Li compound is selected from the group consisting of Li carbonate, Li oxide, Li hydroxide, Li acetate, Li chloride, Li fluoride, Li nitrate, Li sulfate, or a mixture thereof. The process of being something; b) heating the precursor to form a lithium transition metal oxide cathode material having a single phase structure. Includes:

[0015] In some embodiments, at least one metal in elemental form is mixed with other metal compounds, such as oxides, carbonates, sulfates, and the like, and a lithium source. This creates a wide range of options for raw material selection depending on the cost, availability, and properties of each feedstock. Dopants selected from the group consisting of elemental forms of Na, B, Al, Mg, Zr, Nb, Fe, Si, P, Mo, Ba, Sr, Ca, Zn, Cr, V, W, Nd, La, Cs, Ta, Ce, Cu, Eu, Ti, Sn, Sb, Pb, Bi, or Rb, or compounds thereof, can also be added in the mixing process to modify the properties of the lithium transition metal oxide.

[0016] The use of metals in elemental form can streamline the overall manufacturing process by eliminating the need for suppliers to purify metal compounds. Dry solid-phase mixing also produces no wastewater and allows for the use of Class 2 insoluble feedstocks, making the overall process more efficient.

[0017] During the lithiation process, the lithium source added to the mixing process can be LiOH, LiOH·H2O, Li2CO3, Li2O, and mixtures thereof, and the amount of lithium added is determined by the stoichiometric formula Li 1+x [(Ni n Mn m Co c Al a ) 1-y A y ] 1-x Within 20% of O. If desired, the lithium source can be added together with all of the transition metal feedstock in a single-step mixing process, or can be added later after all of the transition metal feedstock has been mixed.

[0018] In the mixing process, dry solid-phase mixing can be performed using mechanical mixing techniques, including, but not limited to, ball mills, bead mills, impact mills, automatic pulverizers, high-speed mixers, trituration, acoustic mixers, mechanofusion, or blenders. Depending on the particle size of the feedstock, impact milling or ball milling may be required to further reduce the particle size and create a homogeneous mixture. In ball milling, the selection and size of media can be varied based on the acceptable metal impurities, material hardness, and milling efficiency. If necessary, wet mixing using a small amount of water or ethanol (which produces at least 90% less liquid by-product than traditional processes) can be performed to facilitate milling and material combination. When a small amount of liquid is used, the solid:liquid ratio is greater than 5:1, greater than 9:1, greater than 10:1, greater than 12:1, greater than 15:1, or greater than 20:1 by mass. In a preferred embodiment, the amount of liquid is sufficient to create a gel or slurry, but not enough to suspend the solids in the liquid.

[0019] The mixed lithium transition metal oxide precursor is calcined in a furnace under pure oxygen, an inert gas, dry air, air, or a combination thereof. Calcination can be performed in a single-step heating protocol up to the maximum temperature or in multiple steps with temperature holds therebetween. The calcination temperature, including temperature holds, ranges between 450 and 1000°C, and the total sintering time ranges between 10 and 100 hours. Multiple-step heating is preferred when the raw materials are dense or large and when the Li source has low reactivity, such as in the case of Li2CO3.

[0020] In some embodiments, post-modification such as reheating is performed to increase crystallinity, decrease cation mixing, reduce lithium residues, smooth the surface of the lithium transition metal oxide product, or a combination thereof. Reheating can be performed under pure oxygen, inert gas, dry air, air, or a combination thereof at temperatures greater than 500°C for greater than 1 hour. The choice of atmosphere depends on the moisture sensitivity, amount of impurities, and stoichiometry of the lithium transition metal oxide product.

[0021] The calcined lithium transition metal oxide may contain some particle agglomerations that can be pulverized using an impact mill, jet mill, or pulverizer. In at least one embodiment, deagglomeration is performed to increase particle homogeneity, create a monomodal particle size distribution, and reduce grain boundaries between particles. This can increase electrode packing efficiency and reduce the likelihood of cell failure, which typically results from cracks between grain boundaries.

[0022] Lithium transition metal oxide products can be prepared with a single-phase structure and high crystallinity using elemental metal feedstocks. A well-developed crystal structure is indicated by the percentage of cation mixing; this is the amount of Ni in the Li layer, and is less than 6%. Materials with low cation mixing may be less susceptible to phase transformations and crack formation during cycling. Low cation mixing is beneficial for rate capability and cycling stability when the material is assembled into a battery cell.

[0023] The lithium transition metal oxide products can be used as cathode materials for secondary batteries in a wide range of commercial applications. Different stoichiometric compositions provide different energy densities, safety features, and cycling stability suitable for use in various applications. The conversion of elemental metal feedstocks to the lithium transition metal oxide products disclosed in embodiments herein is a dry, streamlined process that replaces the complex wet methods used in the cathode materials manufacturing industry. [Brief explanation of the drawings]

[0024] [Figure 1] 1 shows SEM images of N6-1, N6-2, N6-3, and N6-4 materials of Example 1. [Figure 2] FIG. 1 shows XRD patterns of N6-1, N6-2, N6-3, and N6-4 materials of Example 1. [Figure 3] [Figure 3a] First cycle charge / discharge profile at C / 20 for coin cells made with N6-3 material. [Figure 3b] Capacity retention for coin cells made with N6-3 material. [Figure 4] FIG. 1 shows XRD patterns of N6-5 and N6-6 materials of Example 2. [Figure 5] FIG. 1 shows SEM images of N8-1 and N8-2 materials of Example 3. [Figure 6] FIG. 1 shows XRD patterns of N8-1 and N8-2 materials of Example 3. [Figure 7] [Fig. 7a] First cycle charge / discharge profiles at C / 20 for coin cells made with N8-1 material. [Fig. 7b] First cycle charge / discharge profiles at C / 20 for coin cells made with N8-2 material. [Fig. 7c] Capacity retention for coin cells made with N8-1 material. [Fig. 7d] Capacity retention for coin cells made with N8-2 material. [Figure 8][Fig. 8a] SEM images of N8-3 material at various magnifications in Example 4. [Fig. 8b] SEM images of N8-3 material at various magnifications in Example 4. [Fig. 8c] EDX elemental mapping of Ni in N8-3 material. [Fig. 8d] EDX elemental mapping of Co in N8-3 material. [Fig. 8e] EDX elemental mapping of Mn in N8-3 material. [Fig. 8f] EDX elemental mapping of Al in N8-3 material. [Figure 9] FIG. 1 shows the XRD pattern of N8-3 material of Example 4. [Figure 10] [Fig. 10a] SEM images of N8-4 material at various magnifications in Example 5. [Fig. 10b] SEM images of N8-4 material at various magnifications in Example 5. [Fig. 10c] EDX elemental mapping of Ni in N8-4 material. [Fig. 10d] EDX elemental mapping of Co in N8-4 material. [Fig. 10e] EDX elemental mapping of Mn in N8-4 material. [Figure 11] FIG. 1 shows the XRD pattern of N8-4 material of Example 5. DETAILED DESCRIPTION OF THE INVENTION

[0025] Embodiments of the present disclosure may relate to the production of lithium transition metal oxide electrode materials and products thereof. In preferred embodiments, the method is a dry or substantially dry method. The method may allow for the production of lithium transition metal oxide electrode materials with minimal or no solvent or wastewater by-products.

[0026] The production of lithium transition metal oxide electrode materials can proceed by mixing a precursor mixture in the absence of a solvent, followed by heating the precursor mixture. The precursor mixture can be a combination containing lithium, nickel, manganese, cobalt, aluminum, and at least two dopants. The mixed and heated precursor mixture generally has the formula Li 1+x [(Ni n Mn m Co c Ala ) 1-y A y ] 1-x A lithium transition metal oxide electrode material having the formula: O2 (where: -0.2≦x≦0.2; n+m+c+a=1; n≧0; m≧0; c≧0; a≧0; A is a metal dopant; and 0≦y≦0.05). The dopant of the precursor mixture may be selected from Na, B, Al, Mg, Zr, Nb, Fe, Si, P, Mo, Ba, Sr, Ca, Zn, Cr, V, W, Nd, La, Cs, Ta, Ce, Cu, Eu, Ti, Sn, Sb, Pb, Bi, Rb, or a mixture thereof.

[0027] In any of the embodiments disclosed herein, the metals used may be elemental metals. In at least one embodiment, the transition metals Ni, Mn, Co, and Al are provided in elemental form. In at least one embodiment, all of the transition metals are provided in elemental form. The elemental form of a metal may include metals composed of a single chemical element or its oxide. The elemental form may exclude cationic / anionic salts of metal compounds or compounds containing the metal in an oxidized state. In embodiments disclosed herein, the elemental form of a metal may be substantially free of other chemical elements.

[0028] The elemental form of the metal may include the elemental metal as a raw material. In embodiments herein, the elemental metal may be a sufficiently pure or substantially pure metal. The purity of the metal may be at least 50% pure, at least 60% pure, at least 70% pure, at least 80% pure, at least 90% pure, at least 95% pure, or at least 99% pure. The metal may be provided in a sufficiently pure form, such as a Class 2 feedstock. The metal may be provided as an insoluble feedstock.

[0029] In any of the embodiments disclosed herein, the precursor mixture may be heated with or without a holding period, and with or without post-treatment or reheating. Heat treatment of the precursor mixture may be used to oxidize the precursor mixture and produce the structure of the lithium transition metal oxide electrode material. Heating the precursor mixture may be a high-temperature sintering process. The sintering process may be performed in the presence of oxygen. Alternatively, the sintering process may be performed in the presence of an inert atmosphere, oxygen, a reduced oxygen partial pressure gas, dry air, or air. The inert atmosphere may be composed of an inert gas such as helium, argon, or neon, or may be in the presence of nitrogen gas (N). Sintering of the lithium precursor may be performed in a substantially water-free environment. The sintering temperature may be elevated above the melting temperature of at least one metal in the precursor solution. For example, sintering may be performed above the melting point of lithium or aluminum. The sintering temperature in any of the embodiments herein may be greater than 500° C., greater than 550° C., greater than 600° C., greater than 650° C., greater than 700° C., greater than 750° C., greater than 800° C., greater than 900° C., or greater than 1000° C. The post-modification reheat temperature may similarly be in the temperature ranges disclosed above and may be greater than 500° C. Heating of the precursor may range from about 1 to 150 hours, about 5 to 120 hours, about 10 to 100 hours, or at least 5 hours.

[0030] In any of the embodiments disclosed herein, the mixing of the precursor solutions may be performed in the absence of a solvent. The mixing may be performed in the absence of water, resulting in a mixing process that eliminates the production of wastewater as a by-product. In any of the embodiments disclosed herein, the substantially water-free environment may be substantially free of liquid water or liquid solvent. The liquid solvent may be a polar solvent or a non-polar solvent, such as an organic solvent. In embodiments herein, the method may also exclude the use of acidic or basic solutions.

[0031] Dry mixing may be performed according to any dry mixing process known in the art, as long as the precursor solutions can be mixed in the absence of a liquid solvent. Examples of suitable dry mixing techniques may be ball milling, automated grinding, impact milling, high-speed mixing, trituration, acoustic mixing, mechanofusion, or blending. Mixing may be performed by fluidization or pneumatic processes, or may be combined with these. Mixing may be performed at elevated temperatures.

[0032] The various steps of the processes disclosed in the embodiments herein may be combined together or separated into two distinct steps. For example, the addition of lithium to the precursor solution or the transition metal and / or dopant may be performed in a single lithiation operation, or the addition of lithium may be performed stepwise in two mixing steps. Lithium may be added in excess of the other metals in the precursor solution. Lithium may be in stoichiometric excess over the other elements by less than 40%, less than 30%, less than 20%, less than 15%, less than 10%, less than 5%, or less than 1%.

[0033] The stoichiometric ratios disclosed in any of the embodiments herein may be non-integer ratios. For example, in at least one embodiment, the lithium transition metal oxide electrode material produced under the present disclosure has the formula LiNi 0.6 Mn 0.2 Co 0.2 O2, LiNi 0.83 Mn 0.06 Co 0.11 O2 or LiNi 0.8 Mn 0.1 Co 0.1 O2 (where the ratios of Li to Ni to Mn to Co to O2 are not described by integers, but by fractions or decimals). In certain circumstances, the subscripts in the formula may be multiplied by a value to obtain an integer subscript, but the stoichiometric ratios of the chemical elements in the lithium transition metal oxide electrode material will remain the same.

[0034] The lithium transition metal oxide electrode material in any of the embodiments disclosed herein may be incorporated into a battery. The battery may be a lithium-ion battery, and the lithium transition metal oxide electrode material may be incorporated as an active material in the cathode of the battery. The battery may contain additional components such as a liquid or solid electrolyte, a membrane, an anode active material, a current collector, and supporting additives such as binders and conductivity enhancers for the anode and cathode materials, and structural features such as a battery casing. The battery may be a lithium-ion battery. The battery anode active material may be optimized with the lithium transition metal oxide electrode material in any of the embodiments disclosed herein to generate the highest electrochemical cell potential. The battery components may be substantially pure and may be optimized to reduce side reactions, such as chemical dendrites, during charging and discharging of the electrochemical cell.

[0035] The lithium transition metal oxide electrode material disclosed in any of the embodiments herein may be incorporated as an active material in a battery cathode. The lithium transition metal oxide electrode material may be incorporated via a dry or wet process. For example, the lithium transition metal oxide electrode material may be attached to a current collector via a binder, with or without compression during attachment.

[0036] The lithium transition metal oxide electrode materials disclosed in the embodiments herein may be a single-phase layered O3 phase. The single-phase O3 structure may be free of Li impurities. The O3 structure advantageously possesses high conductivity, a critical property for cathode materials. Conductivity is a measure of how well a material can conduct electricity. High conductivity is important for cathodes because it allows electrons to flow easily through the material, enabling efficient charge transfer. The O3 structure is also known for its structural stability, allowing it to withstand damage from external factors such as heat and stress. This stability allows cathode materials with the O3 structure to maintain their performance over long periods of time, even in demanding applications.

[0037] The methods and products described in the embodiments herein are superior to traditional methods of the prior art. The embodiments described herein provide a solvent-free method for producing lithium transition metal oxide electrode materials, reducing the adverse environmental impact of excess wastewater and soluble by-products. Furthermore, the materials provided in the precursor mixture may be produced from cost-effective materials, such as elemental metals, metal compounds, and lithium salts, e.g., Li carbonate, Li oxide, Li hydroxide, Li acetate, Li chloride, Li fluoride, Li nitrate, Li sulfate, etc. The wide variety of precursor materials, such as elemental materials or chemical salts and compounds, that can be provided in the precursor mixture enables a more streamlined, environmentally friendly, and cost-effective approach to producing lithium transition metal oxide electrode materials.

[0038] The following is intended to better illustrate the present invention and is exemplary in nature, not limiting in scope, application, or use.

[0039] Material characterization Scanning electron microscope (SEM) images and energy dispersive X-ray spectroscopy (EDX) mapping images were obtained using a Phenom XL G2 Desktop SEM under backscattered electron mode with an accelerating voltage of 15 kV. Powder samples were prepared by adhering them onto sample stubs using conductive carbon tape.

[0040] The X-ray diffraction (XRD) patterns of the powders were measured using a Bruker D8 Advance diffractometer equipped with a Cu Kα X-ray source and a diffracted beam monochromator. Rietveld analysis was performed on the measured XRD patterns to quantify the amount of cation mixing: Ni in the Li layer using Rietica software.

[0041] Cell preparation and electrochemical evaluation The electrode slurry was prepared by mixing the active material, carbon black (Imerys / Timcal SuperP), and polyvinylidene fluoride (PVDF, Solvay Solef 5130) in a mass ratio of 0.94:0.04:0.02 in N-methyl-2-pyrrolidone (NMP, Fisher Scientific, 99.9%) with a 50% solids content using a planetary mixer. The slurry was coated onto a 15 μm aluminum foil sheet using a doctor blade method, dried in air on a drying table at 90 °C, and then finally dried overnight in a vacuum oven at 100–120 °C. The dried electrode was compressed using a calendar rolling and perforated with a diameter of 13.00 mm. The areal active mass loading was approximately 18–22 mg / cm. 2 Coin cells were fabricated in an Ar-filled glovebox using a CR2032 coin-shaped casing containing one sheet of the active electrode, a Li foil counter electrode, two layers of separator (Celgard 2500), and 100 μL of 1.2 M LiPF in a solution of ethylene carbonate:ethyl methyl carbonate:dimethyl carbonate (EC:EMC:DMC (25:5:70 wt%), CapChem) electrolyte. Galvanostatic cycling measurements were performed at a controlled temperature of 25 °C using a NOVONIX ultra-high precision coulometry system. [Example]

[0042] Example 1. NMC622 made from all elemental metals using a high speed mixer. LiNi 0.6 Mn 0.2 Co 0.2 This example of O2 (NMC622) was prepared by adding Ni powder, Mn powder, Co powder, and 5% excess Li2O3 in a stoichiometric ratio of LiNi 0.6 Mn 0.2 Co 0.2The powders were prepared by mixing in O2 with a high-speed conical mixer (Xinguang, VCH-30L) at 750 rpm for 1.5 hours. The mixed powders were then transferred to alumina crucibles and heated in a tube furnace at various sintering temperatures and atmospheres for 20 hours. Table 1 lists the samples heated at 920 °C in O2 (N6-1), 940 °C in O2 (N6-2), 960 °C in O2 (N6-3), and 940 °C in air (N6-4). All samples were heated at 600 °C for 3 hours, then allowed to reach the final sintering temperature, which was held for 20 hours, and then cooled to room temperature. Heating and cooling rates of 10 °C / min and 1 °C / min were used, respectively. Figure 1 shows that all samples have a single-crystal morphology with smooth surfaces. The materials became less agglomerated with increasing sintering temperature. The sample prepared in air (Figure 1d) showed slightly larger grain size and more particle agglomeration. Figure 2 shows the XRD patterns of all samples with pure single-phase layered O3 phase without Li impurities. A clear peak separation between (108) / (110) at 65° can be observed in all samples, indicating a very high and well-ordered crystallinity. The cation mixing was varied between 2.5 and 5.0%, as listed in Table 1. Figure 3 shows examples of the electrochemical performance of N6-3 materials. Figure 3a shows the XRD patterns of N6-3 materials prepared in air with Li impurities at C / 20. + Figure 3b shows the charge-discharge profile of the first cycle, tested between 2.8 and 4.5 V vs. Li. A reversible discharge capacity of 189.5 mAh / g can be obtained with an irreversible capacity of 11.42%. Figure 3b shows the galvanostatic cycling behavior of an N6-3 half cell tested at C / 20 formation for 2 cycles, followed by C / 5 for 25 cycles and C / 20 checkup for 2 cycles. The C / 5 capacity retention was approximately 85.5% after 25 cycles.

[0043] [Table 1]

[0044] Example 2. Post-modification of NMC622 made from all elemental metals using an automated grinder. In this example, NMC622 was prepared by mixing Ni powder, Mn powder, Co powder, and 5% excess LiOH·H2O in a stoichiometric ratio of LiNi 0.6 Mn 0.2 Co 0.2 The N6-5 sample was prepared by mixing the powders in an automatic mill in O2 for 20 minutes to form a homogeneous mixture. The mixed powders were then transferred into an alumina crucible and heated in a tube furnace at 600°C for 3 hours, then in O2 at 940°C for 20 hours to form N6-5. After cooling to room temperature, sample N6-5 was removed from the tube furnace and manually ground using a mortar and pestle. The sample was post-treated by heating in a tube furnace, heated to 940°C in O2 for 12 hours, and then cooled to room temperature to form N6-6. The heating rate for both samples was 10°C / min, and the cooling rate was 1°C / min. The sintering conditions are listed in Table 2. Figure 4a shows the XRD of N6-5 after the first heating step. Peak broadening away from the O3 layered phase can be observed, as can the Li impurity peak at approximately 33°, indicating that the material is not a pure phase and the lithiation reaction was incomplete. Figure 4b shows the XRD of sample N6-6 after reheating at 940 °C for 12 h. The intensities of the (003) plane at 18° and the (104) plane at 43° are significantly increased, and the (108) / (110) planes at approximately 65° are clearly separated without peak broadening, indicating that the N6-6 material has become a pure layered phase. The cation mixing of the N6-6 material was 4.16%, similar to that of the N6-2 material prepared at the same sintering temperature as Li2O3.

[0045] [Table 2]

[0046] Example 3. NMC811 made from all elemental metals using an automated grinder. In this example, NMC811 is a mixture of Ni powder, Mn powder, Co powder, and Li2CO3 in a stoichiometric ratio of LiNi 0.8 Mn 0.1 Co 0.1The powders were prepared by mixing in an automatic mill with O2 for 20 minutes to form a homogeneous mixture. As listed in Table 3, 1% excess Li2CO3 was used to form the N8-1 sample, and 5% excess Li2CO3 was used to form the N8-2 sample. The mixed powders were transferred into an alumina crucible and sequentially heated in a tube furnace at 600 °C for 3 hours, 920 °C for 20 hours, and 870 °C for 5 hours, then cooled to room temperature under an O2 atmosphere. The heating and cooling rates were 10 °C / min and 1 °C / min, respectively. Figure 5 shows SEM images of N8-1 and N8-2, demonstrating that the synthesized powders have single-crystalline morphologies with smooth surfaces and well-defined facets. Figure 6 shows the XRD patterns of the N8-1 and N8-2 materials. Both samples exhibited well-developed layered structures with clear (108) / (110) peak separation, indicating a very high degree of crystallinity. No lithium impurities were observed. Both N8-1 and N8-2 materials showed very little cation mixing, 1.29% and 1.81%, respectively. Figures 7a and 7b show the Li / Li ratios at C / 20 for N8-1 and N8-2 materials. + Figures 7c and 7d show the charge-discharge profiles of the first cycle tested between 2.8 and 4.3 V vs. 100 kJ / s. High reversible discharge capacities of 191.1 mAh / g and 190.5 mA / g and irreversible capacities of 13.36% and 12.76% can be obtained for N8-1 and N8-2, respectively. Both samples also exhibit very small overpotentials and small voltage hysteresis during the initial charge, indicating low material impedance. Figures 7c and 7d show the galvanostatic cycling behavior of N8-1 and N8-2 half cells tested for two cycles at C-20 formation, followed by 25 cycles at C / 5 and two cycles at C / 20 checkup. The C / 5 capacity retention was 93.56% and 93.90%, respectively, after 25 cycles.

[0047] [Table 3]

[0048] Example 4. NMCA made from Ni, Co, and Mn elemental metals and Al2O3 using an automatic pulverizer. NMCA powder was mixed with Ni powder, Mn powder, Co powder, Al2O3 powder, and 1% excess Li2CO3 in a stoichiometric ratio of Li(Ni 0.8 Mn 0.1 Co 0.1 ) 0.99 Al 0.01 The N8-3 material was synthesized by mixing the powders in an automatic mill with O2 for 20 minutes to form a homogeneous mixture. The mixed powders were transferred to an alumina crucible and sequentially heated in a tube furnace at 600°C for 3 hours, 920°C for 20 hours, and 870°C for 5 hours, then cooled to room temperature under an O2 atmosphere to form N8-3. Figures 8a and 8b show SEM images of the N8-3 material at various magnifications. A uniform single-crystalline morphology was observed without agglomerations. The material has a smooth surface and well-defined facets. Figures 8c–8f show EDX elemental mapping images of Ni, Co, Mn, and Al, respectively. All elements showed homogeneous elemental distribution in all particles, even with only 1 mol% Al. This confirms the successful synthesis and lithiation of the Ni-rich cathode fabricated from elemental metal raw materials. Figure 9 shows the XRD pattern of the N8-3 material, which has a pure, single-layered O3 phase without Li impurities. A clear peak separation between (108) / (110) at 65° can be observed, indicating a very high and well-ordered crystallinity. The cation mixing calculated from Rietveld analysis was 1.61%. [Example]

[0049] Example 5. NMC811 made from elemental metals mixed with metal compounds (NiO+Mn+Co). In this example, NMC811 is a mixture of NiO powder, Mn powder, Co powder, and 1% excess Li2CO3 in a stoichiometric ratio of LiNi 0.8 Mn 0.1 Co 0.1The cathode powder was prepared by mixing the powder in an automatic grinder with O2 for 20 minutes to form a homogeneous mixture. The mixed powder was transferred into an alumina crucible and sequentially heated in a tube furnace at 600 °C for 3 hours, 920 °C for 20 hours, and 870 °C for 5 hours, then cooled to room temperature under an O2 atmosphere to form N8-4. Figures 10a and 10b show SEM images of the N8-4 material at various magnifications. A uniform single-crystalline morphology was observed without agglomerates or incompletely lithiated particles. The cathode powder exhibited smooth surfaces and well-defined facets. Figures 10c-10e show EDX elemental mapping images of Ni, Co, and Mn, respectively. All elements were homogeneously distributed throughout the particles. Figure 11 shows the XRD pattern of the N8-4 material, which has a pure, single-layered O3 phase without Li impurities. A clear peak separation between (108) / (110) at 65° can be observed, indicating a very high and well-ordered crystallinity. The cation mixing calculated from Rietveld analysis was 1.75%.

[0050] Alternative example Accordingly, some aspects described herein relate to the following numbered alternatives: 1. Empirical formula (1) Li 1+x [(Ni n Mn m Co c Al a ) 1-y A y ] 1-x O2 (in the formula: -0.2 ≤ x ≤ 0.2; n+m+c+a=1; n≧0; m≧0; c≧0; a≧0; A is a metal dopant; 1. A method for preparing a lithium transition metal oxide positive electrode material for a secondary battery having a y of 0≦y≦0.05, comprising: (A) preparing a precursor mixture by combining together stoichiometric amounts of one or more lithium compounds according to formula (1): - at least one transition metal is in elemental form and is selected from the group consisting of Ni, Mn, and Co to form the precursor mixture; - the compounds of the remaining metals are selected from the group consisting of oxides, hydroxides, oxyhydroxides, carbonates, sulfates, nitrates, acetates, and combinations thereof; - the one or more Li compounds are selected from the group consisting of Li carbonate, Li oxide, Li hydroxide, Li acetate, Li chloride, Li fluoride, Li nitrate, Li sulfate, and mixtures thereof; and (B) heating the precursor mixture to form a lithium transition metal oxide cathode material. A method comprising:

[0051] 2. The method of alternative 1, wherein the lithium transition metal oxide cathode material has a single phase structure.

[0052] 3. The method of Alternative 1 or any of the preceding alternatives, wherein the lithium transition metal oxide cathode material is a single-phase crystalline structure.

[0053] 4. The method of Alternative 1 or any of the preceding alternatives, wherein the lithium transition metal oxide cathode material is a single-phase structure free of lithium impurities.

[0054] 5. The method of Alternative 1 or any of the preceding alternatives, wherein the step of preparing the precursor mixture is performed by dry mixing using a ball mill, an automatic grinder, an impact mill, a high-speed mixer, trituration, an acoustic mixer, mechanofusion, or a blender, or wet mixing using a wet mill, or a combination thereof.

[0055] 6. The method of Alternative 1 or any of the preceding alternatives, wherein preparing the precursor mixture is performed in two steps, the first mixing step being performed without the one or more Li compounds, and the one or more Li compounds being added in the second mixing step.

[0056] 7. The method of Alternative 1 or any of the preceding alternatives, wherein the transition metal of at least one transition metal in the precursor mixture is in elemental form.

[0057] 8. The method of Alternative 1 or any of the preceding alternatives, wherein A is selected from the group consisting of: Na, B, Al, Mg, Zr, Nb, Fe, Si, P, Mo, Ba, Sr, Ca, Zn, Cr, V, W, Nd, La, Cs, Ta, Ce, Cu, Eu, Ti, Sn, Sb, Pb, Bi, Rb, and mixtures thereof.

[0058] 9. The method of Alternative 1 or any of the preceding alternatives, wherein the preparation of the precursor mixture uses feedstocks: compounds of Ni containing no other metal elements other than Ni; compounds of Mn containing no other metal elements other than Mn; compounds of Co containing no other metal elements other than Co; compounds of Al containing no other metal elements other than Al.

[0059] 10. The method of alternative 1 or any of the preceding alternatives, wherein y is zero.

[0060] 11. The method of alternative 1 or any of the preceding alternatives, wherein n is zero.

[0061] 12. The method of alternative 1 or any of the preceding alternatives, wherein m is zero.

[0062] 13. The method of Alternative 1 or any of the preceding alternatives, wherein c is zero.

[0063] 14. The method of alternative 1 or any of the preceding alternatives, wherein a is zero.

[0064] 15. The method of Alternative 1 or any of the preceding alternatives, wherein y is not zero and at least one of n, m, c, and a is zero.

[0065] 16. The lithium transition metal oxide is LiNi 0.6 Mn 0.2 Co 0.2 O2 or LiNi 0.83 Mn 0.06 Co 0.11 The method of Alternative 1 or any of the preceding alternatives, wherein O2.

[0066] 17. The lithium transition metal oxide is LiNi 0.8 Mn 0.1 Co 0.1 The method of Alternative 1 or any of the preceding alternatives, wherein O2.

[0067] 18. The method of Alternative 1 or any of the preceding alternatives, wherein heating the precursor mixture is carried out under an atmosphere of an inert gas, oxygen, a reduced oxygen partial pressure gas, dry air, or air.

[0068] 19. The method of Alternative 1 or any of the preceding alternatives, wherein the heating temperature is in the range of between about 450-1000°C conducted in one or multiple temperature holds.

[0069] 20. The method of Alternative 1 or any of the preceding alternatives, wherein the heating temperature is in the range of between about 700-1000°C conducted in one or multiple temperature holds.

[0070] 21. The method of Alternative 1 or any of the preceding alternatives, wherein the heating temperature is in the range of between about 450-750°C conducted in one or multiple temperature holds.

[0071] 22. The method of Alternative 1 or any of the preceding alternatives, wherein the total heating time is in the range of between about 10 and 100 hours.

[0072] 23. The method of Alternative 1 or any of the preceding alternatives, wherein the total heating time is in the range of between about 50 and 100 hours.

[0073] 24. The method of Alternative 1 or any of the preceding alternatives, wherein the lithium compound is added at no more than 20% above stoichiometric amount.

[0074] 25. The method of Alternative 1 or any of the preceding alternatives, wherein the lithiation is carried out in one step.

[0075] 26. The method of Alternative 1 or any of the preceding alternatives, wherein the lithiation is carried out in two steps, the first lithiation step being carried out with -0.2≦x<0 and the second lithiation step being carried out with a stoichiometric amount of remaining Li totaling x≦0.20.

[0076] 27. The method of Alternative 1 or any of the preceding alternatives, wherein the lithiation is carried out in two steps, the first lithiation step being carried out with -0.1≦x<0 and the second lithiation step being carried out with a stoichiometric amount of remaining Li totaling x≦0.10.

[0077] 28. The method of Alternative 1 or any of the preceding alternatives, wherein post-modification is performed on the lithium transition metal oxide by further reheating under an atmosphere of inert gas, oxygen, reduced oxygen partial pressure gas, dry air, and air.

[0078] 29. The method of Alternative 1 or any of the preceding alternatives, wherein the reheat temperature is greater than 500°C for greater than 1 hour.

[0079] 30. The method of Alternative 1 or any of the preceding alternatives, wherein the percentage of cation mixing, the amount of Ni in the Li layer, is less than 6.0 mol % in the lithium transition metal oxide product.

[0080] 31. The method of Alternative 1 or any of the preceding alternatives, wherein the step of combining the precursor mixtures comprises mixing the precursor mixtures in the absence of a solvent.

[0081] 32. The method of Alternative 1 or any of the preceding alternatives, wherein the step of combining the precursor mixture includes mixing the precursor mixture in a substantially water-free environment.

[0082] 33. The method of Alternative 1 or any of the preceding alternatives, wherein the precursor mixture is mixed by a wet process and the solid:liquid ratio is at least 5:1 by mass.

[0083] 34. The method of Alternative 1 or any of the preceding alternatives, wherein the method is carried out without adding any reaction accelerators or nuclei in the mixing process.

[0084] 35. The method of Alternative 1 or any of the preceding alternatives, wherein the precursor mixture is mixed in the absence of a slurry.

[0085] 36. The method of Alternative 1 or any of the preceding alternatives, wherein the precursor mixture is mixed in the absence of an organic solvent.

[0086] 36. The method of Alternative 1 or any of the preceding alternatives, wherein the precursor mixture is mixed in the absence of a protic solvent.

[0087] 37. The method of Alternative 1 or any of the preceding alternatives, wherein the precursor mixture is mixed in the absence of a polar solvent.

[0088] 38. The method of Alternative 1 or any of the preceding alternatives, wherein the precursor mixture is mixed in the absence of a non-polar solvent.

[0089] 39. The method of Alternative 1 or any of the preceding alternatives, wherein the precursor mixture is mixed in the absence of an acidic or basic solution.

[0090] 40. The method of Alternative 1 or any of the preceding alternatives, wherein the precursor mixture is mixed in a solid state free of solvent residues.

[0091] 41. The method of Alternative 1 or any of the preceding alternatives, wherein the mixing step and the heating step are performed in parallel.

[0092] 42. The method of Alternative 1 or any of the preceding alternatives, wherein -0.19≦x≦0.19.

[0093] 43. The method of Alternative 1 or any of the preceding alternatives, wherein -0.18≦x≦0.18.

[0094] 44. The method of Alternative 1 or any of the preceding alternatives, wherein -0.15≦x≦0.15.

[0095] 45. The method of Alternative 1 or any of the preceding alternatives, wherein -0.12≦x≦0.12.

[0096] 46. ​​The method of Alternative 1 or any of the preceding alternatives, wherein -0.1≦x≦0.1.

[0097] 47. The method of alternative 1 or any of the preceding alternatives, where x=0.

[0098] 48. The method of Alternative 1 or any of the preceding alternatives, wherein 0≦y≦0.04.

[0099] 49. The method of Alternative 1 or any of the preceding alternatives, wherein 0≦y≦0.03.

[0100] 50. The method of Alternative 1 or any of the preceding alternatives, wherein 0≦y≦0.02.

[0101] 51. The method of Alternative 1 or any of the preceding alternatives, wherein 0≦y≦0.01.

[0102] 52. The method of Alternative 1 or any of the preceding alternatives, wherein 0≦y≦0.001.

[0103] 53. The method of Alternative 1 or any of the preceding alternatives, wherein Ni is provided in elemental form.

[0104] 54. The method of Alternative 1 or any of the preceding alternatives, wherein Mn is provided in elemental form.

[0105] 55. The method of Alternative 1 or any of the preceding alternatives, wherein Co is provided in its elemental form.

[0106] 56. The method of Alternative 1 or any of the preceding alternatives, wherein the combining step is dry solid-phase mixing that does not produce wastewater.

[0107] 57. The method of Alternative 1 or any of the preceding alternatives, wherein the one or more elements or compounds of Ni, one or more elements or compounds of Mn, one or more elements or compounds of Co, one or more elements or compounds of Al, and / or one or more elements or compounds of metal dopants is a Class 2 feedstock.

[0108] 58. The method of Alternative 1 or any of the preceding alternatives, wherein the one or more elements or compounds of Ni, one or more elements or compounds of Mn, one or more elements or compounds of Co, one or more elements or compounds of Al, and / or one or more elements or compounds of metal dopants is a Class 2 insoluble feedstock.

[0109] 59. The method of Alternative 1 or any of the preceding alternatives, wherein one or more elements or compounds of Ni, one or more elements or compounds of Mn, one or more elements or compounds of Co, one or more elements or compounds of Al, and / or one or more elements or compounds of metal dopants are included as raw materials.

[0110] 60. The method of Alternative 1 or any of the preceding alternatives, wherein one or more elements or compounds of Ni, one or more elements or compounds of Mn, one or more elements or compounds of Co, one or more elements or compounds of Al, and / or one or more elements or compounds of metal dopants are included in powder form.

[0111] 61. The method of Alternative 1 or any of the preceding alternatives, wherein one or more elements or compounds of Ni, one or more elements or compounds of Mn, one or more elements or compounds of Co, one or more elements or compounds of Al, and / or one or more elements or compounds of metal dopants are included in powder form having a D50 of less than 1,000 microns.

[0112] 62. The method of Alternative 1 or any of the preceding alternatives, wherein one or more elements or compounds of Ni, one or more elements or compounds of Mn, one or more elements or compounds of Co, one or more elements or compounds of Al, and / or one or more elements or compounds of metal dopants are included in powder form having a D50 of less than 500 microns.

[0113] 63. The method of Alternative 1 or any of the preceding alternatives, wherein the lithium transition metal oxide positive electrode material is free of solvent residues.

[0114] 64. The method of Alternative 1 or any of the preceding alternatives, wherein the metals in the precursor mixture are in elemental form, except for Li.

[0115] 65. The method of Alternative 1 or any of the preceding alternatives, further comprising pulverizing the heated precursor mixture through at least one of impact milling, jet milling, or grinding.

[0116] 66. A secondary battery comprising an electrode material comprising the lithium transition metal oxide product from the method of Alternative 1.

[0117] 67. The secondary battery of alternative 66, wherein the secondary battery is a lithium ion battery.

[0118] 69. The secondary battery of any one of alternatives 66-68, wherein the secondary battery has a carbon-based anode.

[0119] 70. The secondary battery of any one of alternatives 66-69, wherein the secondary battery has an anode composed of synthetic graphite having a particle size D50 of 5 to 30 μm.

[0120] 71. The secondary battery of any one of alternatives 66-70, wherein the secondary battery has an anode composed of secondary particles agglomerated from primary particles having a particle size D50 of 1 to 15 μm, the secondary particles having a particle size D50 of 5 to 30 μm.

[0121] 72. The secondary battery of any one of alternatives 66-71, wherein the secondary battery has an anode material composed of synthetic graphite and hard carbon, and the hard carbon content is between about 0.25% and 5% by weight of the anode material.

[0122] Additional Embodiments In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be apparent that various modifications and changes may be made therein without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.

[0123] Indeed, while the present invention has been disclosed in the context of certain specific embodiments and examples, those skilled in the art will recognize that the present invention extends beyond the particularly disclosed embodiments to other alternative embodiments and / or uses of the invention, as well as obvious modifications and equivalents thereof. Moreover, while several variations of the embodiments of the present invention have been shown and described in detail, other modifications within the scope of the present invention will be readily apparent to those skilled in the art based on this disclosure. It is contemplated that various combinations or subcombinations of specific features and aspects of the embodiments may be made and still fall within the scope of the present invention. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another to form varying forms of the disclosed embodiments of the present invention. Any methods disclosed herein need not necessarily be performed in the order recited. Accordingly, it is not intended that the scope of the invention disclosed herein be limited by the specific embodiments described above.

[0124] It will be understood that each of the systems and methods of the present disclosure has several innovative aspects, no single one of which alone will cause or require the desired attributes disclosed herein. The various features and processes described above may be used independently of one another or may be combined in various ways. All possible combinations and subcombinations are intended to be encompassed within the scope of the present disclosure.

[0125] Ranges disclosed herein encompass any and all overlaps, subranges, and combinations thereof. Language such as "up to," "at least," "greater than," "less than," "between," and the like, includes the recited numerical value. Numeric values ​​preceded by terms such as "about" or "approximately" are inclusive of the recited numerical value and should be interpreted under the context (e.g., as precisely as reasonably possible under the circumstances, e.g., ±5%, ±10%, ±15%, etc.). For example, "about 3.5 mm" includes "3.5 mm." Language preceded by terms such as "substantially" is inclusive of the recited numerical value and should be interpreted under the context (e.g., as precisely as reasonably possible under the circumstances). For example, "substantially constant" includes "constant." Unless otherwise stated, all measurements are under standard conditions, including temperature and pressure.

[0126] As used herein, a phrase referring to "at least one" of a list of items refers to any combination of those items, including single elements. By way of example, "at least one of A, B, or C" is intended to encompass A, B, C, A and B, A and C, B and C, and A, B, and C. Conjunctive language, such as the phrase "at least one of X, Y, and Z," is ordinarily understood in context to generally be used to convey that an item, term, etc. may be at least one of X, Y, or Z, unless specifically stated otherwise. Thus, such conjunctive language is generally not intended to suggest that a particular embodiment requires that at least one of X, at least one of Y, and at least one of Z, respectively, be present. Headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the devices and methods disclosed herein.

[0127] Thus, the claims are not intended to be limited to the embodiments shown herein but are to be accorded the widest scope consistent with this disclosure and the principles and novel features disclosed herein.

Claims

1. Empirical formula (1): Li １＋ｘ [(Ni ｎ Mn ｍ Co ｃ Al ａ ) １－ｙ A ｙ ] １－ｘ O ２ (1) (In the formula: -0.2≦x≦0.2, n+m+c+a=1, n≧0, m≧0, c≧0, a≧0, A is a metal dopant, and 0≦y≦0.05) 1. A method for preparing a lithium transition metal oxide positive electrode material for a secondary battery having: (A) preparing a precursor mixture by combining together stoichiometric amounts of one or more lithium compounds, one or more elements or compounds of Ni, one or more elements or compounds of Mn, one or more elements or compounds of Co, one or more elements or compounds of Al, and / or one or more elements or compounds of a metal dopant according to formula (1); at least one transition metal is in elemental form and is selected from the group consisting of Ni, Mn, and Co to form said precursor mixture; the compounds of the remaining metals are selected from the group consisting of oxides, hydroxides, oxyhydroxides, carbonates, sulfates, nitrates, acetates, and combinations thereof; - the one or more Li compounds are selected from the group consisting of Li carbonate, Li oxide, Li hydroxide, Li acetate, Li chloride, Li fluoride, Li nitrate, Li sulfate, and mixtures thereof; and (B) heating the precursor mixture to produce the lithium transition metal oxide cathode material having a single phase structure. A method comprising:

2. 10. The method of claim 1, wherein the step of preparing the precursor mixture is carried out by dry mixing using a ball mill, an automatic pulverizer, an impact mill, a high speed mixer, trituration, an acoustic mixer, mechanofusion, or a blender, or by wet mixing using a wet mill, or a combination thereof.

3. 10. The method of claim 1, wherein the step of preparing the precursor mixture is performed in two steps, a first mixing step being performed without one or more Li compounds, and the one or more Li compounds being added in a second mixing step.

4. The method of claim 1 , wherein the transition metal of the at least one transition metal in the precursor mixture is in elemental form.

5. 2. The method of claim 1, wherein A is selected from the group consisting of Na, B, Al, Mg, Zr, Nb, Fe, Si, P, Mo, Ba, Sr, Ca, Zn, Cr, V, W, Nd, La, Cs, Ta, Ce, Cu, Eu, Ti, Sn, Sb, Pb, Bi, Rb, and mixtures thereof.

6. preparing the precursor mixture using a feedstock; The Ni compound does not contain any metal element other than Ni, the Mn compound does not contain any metal element other than Mn, The Co compound does not contain any other metal element other than Co, and The Al compound does not contain any metal element other than Al. The method of claim 1.

7. The method of claim 1 , wherein y is zero.

8. The method of claim 5 , wherein n is zero.

9. The method of claim 5 , wherein m is zero.

10. The method of claim 5 , wherein c is zero.

11. The method of claim 5 , wherein a is zero.

12. The method of claim 1 , wherein y is not zero and at least one of n, m, c, and a is zero.

13. The lithium transition metal oxide is LiNi ０．６ Mn ０．２ Co ０．２ O ２ The method of claim 1, wherein

14. The lithium transition metal oxide is LiNi ０．８ Mn ０．１ Co ０．１ O ２ The method of claim 1, wherein

15. 10. The method of claim 1, wherein the heating of the precursor mixture is carried out under an atmosphere of an inert gas, oxygen, a reduced oxygen partial pressure gas, dry air, or air.

16. 16. The method of claim 15, wherein the heating temperature ranges between about 450 and 1000°C performed in one or multiple temperature holds.

17. 16. The method of claim 15, wherein the total heating time ranges between about 10 and 100 hours.

18. 10. The method of claim 1, wherein the lithium compound is added at no more than 20% above stoichiometric amount.

19. 20. The method of claim 18, wherein the lithiation is carried out in one step.

20. 19. The method of claim 18, wherein the lithiation is carried out in two steps, the first lithiation step being carried out with -0.2≦x<0 and the second lithiation step being carried out with a stoichiometric amount of remaining Li totaling x≦0.

20.

21. 10. The method of claim 1, wherein post-modification is performed on the lithium transition metal oxide by further reheating under an atmosphere of inert gas, oxygen, reduced oxygen partial pressure gas, dry air, or air.

22. 22. The method of claim 21, wherein the reheat temperature is greater than 500°C for greater than 1 hour.

23. 10. The method of claim 1, wherein the percentage of cation mixing, the amount of Ni in the Li layer, is less than 6.0 mol% in the lithium transition metal oxide product.

24. The method of claim 1 , wherein combining the precursor mixture comprises mixing the precursor mixture in the absence of a solvent.

25. The method of claim 1 , further comprising pulverizing the heated precursor mixture through at least one of impact milling, jet milling, or grinding.

26. 10. A secondary Li-ion battery comprising an electrode material comprising the lithium transition metal oxide product from the method of claim 1.

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