Recycling of used cathode materials

Abstract

Methods for recycling used battery materials are provided herein. The recycled materials may be used active cathode materials that are converted into new cathode materials through the processes herein. The used active cathode materials may contain residual battery components, such as battery electrolytes, salts, binders, separator components and carbons. Advantageously, the process may enable the recycling of battery components through an all-dry process that does not require the separation of residual battery components from active cathode materials prior to the heating or recycling. Also disclosed herein are methods for converting a used battery cathode material with a first transition metal stoichiometry to a new battery cathode material with a second transition metal stoichiometry different from the first transition metal stoichiometry.

Description

NOVBS.020WO PATENT RECYCLING OF USED CATHODE MATERIALS BACKGROUND

[0001] The advancement of high energy density Li-ion batteries and Na-ion batteries holds significant technological importance. Typically, commercial Li-ion batteries use a lithium transition metal oxide having a layered rock salt type structure as a cathode active material and graphite as an anode active material. Ongoing research and development efforts are directed at enhancing Li-ion battery electrochemical performance characteristics, such as cycle life, rate capability and initial coulombic efficiency. Additionally, there is significant research aimed at improving production methods to reduce cost, improve sustainability, reduce complexity, reduce material usage, and reduce waste.

[0002] Lithium transition metal oxide cathode materials for Li-ion batteries typically include lithium, one or more transition metals such as nickel (Ni), manganese (Mn), or cobalt (Co), and oxygen. They can also include optional dopants such as magnesium (Mg), aluminum (Al), titanium (Ti), zirconium (Zr), tungsten (W), zinc (Zn), molybdenum (Mo), potassium (K), sodium (Na), silicon (Si), and tantalum (Ta). To enhance their properties, these materials can be coated with compounds such as aluminum oxide (Al2O3), zirconium oxide (ZrO2), or titanium dioxide (TiO2). Due to the significant demand for Li-ion batteries, ensuring a substantial and economical supply of these materials is critical. A common lithium transition metal oxide cathode material for Li-ion batteries is LiCoO2, which is known as LCO. LCO has a layered O3-type structure. Another common lithium transition metal oxide cathode material for Li-ion batteries is Li[Mn1-gGg]2O4, where 0 ≤ g < 0.5 and G is a metal other than Mn, including Ni, Co, Cu, Al, Cr, Ti, Mg or combinations thereof, which is known as LMO. LMO has a spinel structure. Another common lithium transition metal oxide cathode material for Li-ion batteries is LiNidCoeAlfO2, known as NCA, where d + e + f = 1, d > 0.6, and 0.01 ≤ f ≤ 0.1. NCA has a layered O3-type structure. At present, lithium nickel manganese cobalt oxide cathode materials, known as NMC commercially, are preferred cathode materials for commercial Li-ion batteries.

[0003] NMC type cathode materials for Li-ion batteries generally have an O3 layered structure and have the general actual formula Li1+x[(NinMnmCoc)1-aAa]1-xO2, where -0.03 ≤ x ≤ 0.06; n + m + c = 1; n / (n + m + c) > 0.3; m ≥ 0; c ≥ 0; A is a dopant; and 0 ≤ a ≤ 0.05. In some applications NMC is in the form of particles having an average particlesize between 1 μm and 30 μm. In some applications the NMC particles are secondary particles composed of submicron NMC grains, where the average NMC grain size is less than 20% of the average NMC particle size. In other words, if the particle size is 1 μm the average NMC grain size is 0.2 μm or less. NMC having such a secondary particle structure is referred to as polycrystalline NMC, abbreviated here as PC-NMC. Especially desirable in some applications is single crystal NMC, abbreviated as SC-NMC. In some embodiments, SC-NMC particles can consist of a single NMC grain. In some embodiments, SC-NMC particles can consist of multiple NMC grains, where the average NMC grain facet size is greater than 20% of the average particle size. In other words, if the particle size is 1 μm the average NMC grain size is 0.2 μm or more. In some embodiments of SC-NMC, the average particle size is between 1 μm and 30 μm. Single crystal NMCs with high nickel content (x ≥ 0.6) are often used commercially.

[0004] One method for synthesizing SC-NMC or PC-NMC involves initially creating a mixed metal hydroxide precursor particulate or a mixed metal carbonate precursor particulate. This precursor consists of nickel, manganese, cobalt, and optionally, a dopant, and their proportions depend on the composition of the final product NMCs. The precursor particulate is commonly synthesized through the co-precipitation of metal salts in an aqueous solution, followed by filtration, drying, and grinding. The resulting precursor is then mixed with a lithium source (such as particulate LiOH or Li2CO3) in which the amount should exceed the required stoichiometry for the composition of the final product NMCs to compensate for the evaporated lithium during the sintering process. Then the mixture is heated in air or oxygen at high temperatures ranging from 600 to 1000 °C. The co-precipitation method is often used because it produces precursor particulates with the same size as the final desired NMC product particle size. Moreover, the co-precipitation method enables atomic-scale mixing of the transition metals in the precursors. This level of uniformity is important because transition metals diffuse relatively slowly during the high temperature heating process, which can lead to the formation of impurity phases in the final product. If atomic mixing is not homogeneous, it may be necessary to extend the heating time to fully convert the precursor particulates into the single-phase NMC, thereby increasing the probability of cation mixing and production costs. During the heating process, lithium loss through evaporation is a common issue. Extending the heating time can cause more lithium loss, which may result in lithium deficiency in the final product. Furthermore, the co-precipitation method is complex, which involves multiple steps that can result in significant wastewater generation. This method commonly uses soluble metal salts assources of transition metals, which tend to be more expensive than insoluble sources such as carbonates, hydroxides and metal oxides.

[0005] All-dry methods for producing SC-NMC cathodes offer several advantages over traditional co-precipitation process, such as a simplified production process, low cost, and low waste. Examples of all-dry methods for producing SC-NMC are described in international patent application WO2023230537A1, which is incorporated by reference herein in its entirety.

[0006] The increasing demand for lithium-ion batteries has led to a surge in the production and subsequent disposal of NMC cathodes, raising significant environmental and economic concerns. Efficient recycling of NMC cathodes is essential to mitigate these issues and sustain the supply chain for critical materials. The most commonly used methods for recycling spent lithium-ion batteries include pyrometallurgical, hydrometallurgical and direct recycling approaches. Pyrometallurgy recycling includes the process of chemical extraction metallurgy of spent lithium-ion batteries at high temperatures to recover valuable metals based on their chemical and physical properties. The resulting metal-rich residue is subsequently recovered by hydrometallurgical leaching processes. This method is energy intensive and requires large amounts of solvents and leaching agents. Furthermore, lithium is generally not recovered, and the recovered transition metals are in the form of metal salts, which are then utilized in a conventional co-precipitation process for making NMC.

[0007] Hydrometallurgical processes are considered more sustainable due to their high recovery efficiency and relatively lower cost compared to the pyrometallurgical method. Hydrometallurgy is primarily used in chemical processes such as organic or inorganic acidic or alkaline leaching, solvent extraction, precipitation, and electrochemical recycling to recover valuable metals from cathode materials. As with the pyrometallurgical method, hydrometallurgical processes require large amounts of solvents and leaching agents. Furthermore, lithium is also generally not recovered, and the recovered transition metals are in the form of metal salts, which are then utilized in a conventional co- precipitation process for making NMC.

[0008] Direct recycling methods include cathode healing, non-destructive mechanical and electrochemical processes to regenerate electroactive cathode materials, allowing them to be directly used in the production of new batteries. Therefore, direct recycling methods are considered more sustainable than pyrometallurgical and hydrometallurgical methods, as they basically maintain the original structure of the cathode materials, they require fewer solvents and produce less waste.

[0009] In the direct recycling process, used Li-ion batteries are typically sorted according to their chemistries, so that only batteries with identical cathode compositions are utilized. The used batteries may be disassembled by hand or by shredding and the cathode coatings recovered by different methods, such as dissolution of the current collector in a solvent with washing, and drying steps; or by physical abrasion. In some methods binders and residual electrolyte solvent and salts are removed by utilizing a solvent and heating and drying steps. SUMMARY

[0010] In some aspects, the techniques described herein relate to a method of synthesizing a lithium nickel manganese cobalt oxide (NMC) particulate product having the formula Li1+p[(NinMnmCoc)1-aAa]1-pO2, where -0.03 ≤ p ≤ 0.06; n + m + c = 1; n ≥ 0.30; m ≥ 0.05; c ≥ 0; A is a metal dopant; and 0 ≤ a ≤ 0.05; the method including: (a) providing feedstock mixture components that includes one or more used cathode materials recovered from used lithium-ion batteries including: LCO ′, LMO ′, and / or one or more types of NMC ′; (b) combining the feedstock components into a feedstock mixture having the same transition metal and dopant atomic ratio as a desired stoichiometry in the synthesized NMC particulate product; and (c) heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C to produce the NMC particulate; wherein more than about 10 wt% of the feedstock mixture is a used cathode material with a transition metal composition that differs from the transition metal composition of the synthesized NMC particulate product.

[0011] In some aspects, the techniques described herein relate to a method, wherein a degree of lithium deficiency in the one or more used cathode materials is between 0% - 100%.

[0012] In some aspects, the techniques described herein relate to a method, wherein the feedstock mixture further includes a new lithium source, such that the feedstock mixture contains an excess of lithium of up to about 40 atomic% more than the stoichiometry of lithium in the synthesized NMC particulate product.

[0013] In some aspects, the techniques described herein relate to a method, wherein the feedstock mixture further includes at least one of a new nickel source, a new cobalt source, a new manganese source and a dopant source.

[0014] In some aspects, the techniques described herein relate to a method, wherein the new nickel source includes Ni, NiO or mixtures thereof, the new cobalt source includes Co, CoO or mixtures thereof, the new manganese source includes Mn, MnO, Mn3O4, MnO2or mixtures thereof, and the dopant source includes W, WO3, MgO, Bi, Bi2O3, V2O5, Na2O, NaOH, B2O3, Al2O3, NCA′, TiO2, ZnO, ZrO2, MoO3, MoO2 or mixtures thereof.

[0015] In some aspects, the techniques described herein relate to a method that includes a grinding step prior to the combining in which the particle size of all or some of the feedstock mixture components is reduced.

[0016] In some aspects, the techniques described herein relate to a method, wherein the one or more used cathode materials include at least about 1% by weight impurities selected from separator components, electrolyte solvent, electrolyte salt, binder, and / or carbon in the form of carbon black, carbon nanotubes or graphite.

[0017] In some aspects, the techniques described herein relate to a method, further including determining the chemical composition of the feedstock components prior to combining the feedstock components into the feedstock mixture.

[0018] In some aspects, the techniques described herein relate to a method, wherein the product lithium nickel manganese cobalt oxide particulate is a single-crystal cathode material.

[0019] In some aspects, the techniques described herein relate to a method, wherein at least about 50% of the impurities are removed during the heating of the feedstock mixture.

[0020] In some aspects, the techniques described herein relate to a method, wherein the feedstock mixture is free of added solvents that were not recovered from the used lithium-ion batteries.

[0021] In some aspects, the techniques described herein relate to a method, wherein the method is an all-dry process substantially free of water or aqueous solvents.

[0022] In some aspects, the techniques described herein relate to a method, wherein the one or more used cathode materials are not subjected to any separation or purification processes before the combining and are heated at a temperature greater than 300 °C prior to the combining.

[0023] In some aspects, the techniques described herein relate to a method, wherein prior to the combining the one or more used cathode materials are heated at atemperature greater than 300 °C in a CO2(g) atmosphere or in an argon / hydrogen gas mixture

[0024] In some aspects, the techniques described herein relate to an NMC cathode material produced according to the methods herein, wherein the NMC cathode material is free of solvent residues.

[0025] In some aspects, the techniques described herein relate to a NMC cathode material, wherein the NMC cathode material is comprised of single crystal particles.

[0026] In some aspects, the techniques described herein relate to a method for converting a used lithium-ion cathode material into a new lithium-ion cathode material for a battery cell, the method including: providing one or more used cathode materials recovered from one or more battery cells, wherein the one or more used cathode materials have a first transition metal stoichiometry; mixing the one or more used cathode materials with one or more new metal sources or an additional used cathode material in the absence of an added solvent to produce a feedstock mixture; and heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C to produce the new lithium cathode material having a second transition metal stoichiometry different than the first transition metal stoichiometry.

[0027] In some aspects, the techniques described herein relate to a method, wherein the one or more used cathode materials or additional used cathode material have not been separated from impurities prior to the mixing, wherein the impurities include one or more of separator components, electrolyte solvent, electrolyte salt, binder and carbon.

[0028] In some aspects, the techniques described herein relate to a method, wherein at least 1 wt% of the used cathode materials include impurities selected from the group consisting of separator components, electrolyte solvent, electrolyte salt, binder and carbon.

[0029] In some aspects, the techniques described herein relate to a method, wherein at least about 5 wt% of the used cathode materials are the impurities.

[0030] In some aspects, the techniques described herein relate to a method, wherein the one or more new metal sources is at least one of a Ni source, Co source, Mn source or dopant element source.

[0031] In some aspects, the techniques described herein relate to a method, wherein the feedstock mixture includes one or more of a new nickel source, a newmanganese source, a new cobalt source, and / or a new dopant source. In some aspects the feedstock mixture additionally includes a new lithium source.

[0032] In some aspects, the techniques described herein relate to a method, wherein the used cathode materials are not subjected to any separation or purification processes before the mixing.

[0033] In some aspects, the techniques described herein relate to a method, wherein the one or more used cathode materials are mixed with the additional used cathode material, wherein the one or more used cathode materials have a different transition metal stoichiometry from the transition metal stoichiometry of the additional used cathode material

[0034] In some aspects, the techniques described herein relate to a method, wherein the used cathode materials are not subjected to any separation or purification processes after the mixing.

[0035] In some aspects, the techniques described herein relate to a method, wherein the one or more used cathode materials include LCO ′, LMO ′, and / or one or more stoichiometries of NMC ′ and the new lithium cathode material is NMC.

[0036] In some aspects, the techniques described herein relate to a method, wherein the additional used cathode material has a third stoichiometry different from the first stoichiometry

[0037] In some aspects, the techniques described herein relate to a method, wherein the method is an all-dry method, and the entire process is free of water.

[0038] In some aspects, the techniques described herein relate to a method, wherein the one or more used cathode materials include active and inactive cathode materials.

[0039] In some aspects, the techniques described herein relate to a method, wherein the feedstock mixture includes waste materials including waste fines from cathode production, waste electrode slurry, waste cathode scraps that have never been incorporated into a battery cell, and cathode powders from reject cells that have never been cycled.

[0040] In some aspects, the techniques described herein relate to a method, wherein more than 90% of the impurities are removed during the heating of the feedstock mixture.

[0041] In some aspects, the techniques described herein relate to a method, wherein prior to the mixing the one or more used cathode materials are heated at a temperature greater than 300 °C.

[0042] In some aspects, the techniques described herein relate to a method, wherein the heating prior to the mixing is performed in an atmosphere of CO2(g) or in an argon / hydrogen gas mixture.

[0043] In some aspects, the techniques described herein relate to a new lithium- ion cathode material produced according to any of the methods herein, wherein the new lithium-ion cathode material is free of non-electrolyte solvent residues.

[0044] In some aspects, the techniques described herein relate to a new lithium- ion cathode material produced according to any of the methods herein, wherein the new lithium-ion cathode material is a single crystal cathode material or has single crystal morphologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1a is a flow chart for synthesizing a cathode material according to some embodiments herein.

[0046] Figure 1b is an additional flow chart for synthesizing a cathode material according to some embodiments herein.

[0047] Figure 1c is a flow chart for synthesizing a cathode material according to some embodiments herein.

[0048] Figure 1d is an additional flow chart for synthesizing a cathode material according to some embodiments herein.

[0049] Figure 2 shows an XRD pattern of the final NMC811 product of Example 1.

[0050] Figure 3 shows SEM images of the final NMC811 product of Example 1.

[0051] Figure 4 shows EDS compositional maps of the final NMC811 product of Example 1.

[0052] Figure 5 shows the voltage curve of the first cycle for the final NMC811 product of Example 1.

[0053] Figure 6 shows the cycling performance curve for the final NMC811 product of Example 1.

[0054] Figure 7 shows the polarization curve for the final NMC811 product of Example 1.

[0055] Figure 8 shows an XRD pattern of the final NMC811 product of Example 2.

[0056] Figure 9 shows SEM images of the final NMC811 product of Example 2.

[0057] Figure 10 shows EDS compositional maps of the final NMC811 product of Example 2.

[0058] Figure 11 shows the voltage curve of the first cycle for the final NMC811 product of Example 2.

[0059] Figure 12 shows the cycling performance curve for the final NMC811 product of Example 2.

[0060] Figure 13 shows the polarization curve for the final NMC811 product of Example 2.

[0061] Figure 14 shows an XRD pattern of the final NMC811 product of Example 3.

[0062] Figure 15 shows SEM images of the final NMC811 product of Example 3.

[0063] Figure 16 shows EDS compositional maps of the final NMC811 product of Example 3.

[0064] Figure 17 shows the voltage curve of the first cycle for the final NMC811 product of Example 3.

[0065] Figure 18 shows the cycling performance curve for the final NMC811 product of Example 3.

[0066] Figure 19 shows the polarization curve for the final NMC811 product of Example 3.

[0067] Figure 20 shows an XRD pattern of the rock salt phase formed after the first step heating in Example 4.

[0068] Figure 21 shows an XRD pattern of the final NMC811 product of Example 4.

[0069] Figure 22 shows SEM images of the final NMC811 product of Example 4.

[0070] Figure 23 shows EDS compositional maps of the final NMC811 product of Example 4.

[0071] Figure 24 shows the voltage curve of the first cycle for the final NMC811 product of Example 4.

[0072] Figure 25 shows the cycling performance curve for the final NMC811 product of Example 4.

[0073] Figure 26 shows the polarization curve for the final NMC811 product of Example 4.

[0074] Figure 27 shows an XRD pattern of the final NMC811 product of Example 5.

[0075] Figure 28 shows SEM images of the final NMC811 product of Example 5.

[0076] Figure 29 shows EDS compositional maps of the final NMC811 product of Example 5

[0077] Figure 30 shows a voltage curve of the first cycle for the final NMC811 product of Example 5.

[0078] Figure 31 shows the cycling performance curve for the final NMC811 product of Example 5.

[0079] Figure 32 shows the polarization curve for the final NMC811 product of Example 5.

[0080] Figure 33 shows an XRD pattern of the LMO' material of Example 6. The numbers in brackets indicate the Miller indices of identified peaks from the LiMn2O4 spinel structure.

[0081] Figure 34 shows an XRD pattern of the final single crystal NMC811 product of Example 7.

[0082] Figure 35 shows SEM images of the final NMC811 product of Example 7.

[0083] Figure 36 shows EDS compositional maps of the final NMC811 product of Example 7.

[0084] Figure 37 shows the voltage curve of the first cycle for the final NMC811 product of Example 7.

[0085] Figure 38 shows the cycling performance of the final NMC811 product of Example 7.

[0086] Figure 39 shows the polarization curve for the final NMC811 product of Example 7.

[0087] Figure 40 shows an XRD pattern of the LMO'(H2) material of Example 8. Peaks from identified phases are indicated in the figure.

[0088] Figure 41 shows an XRD pattern of the final single crystal NMC811 product of Example 8.

[0089] Figure 42 shows SEM images of the final NMC811 product of Example 8.

[0090] Figure 43 shows EDS compositional maps of the final NMC811 product of Example 8.

[0091] Figure 44 shows the voltage curve of the first cycle for the final NMC811 product of Example 8.

[0092] Figure 45 shows the cycling performance of the final NMC811 product of Example 8.

[0093] Figure 46 shows the polarization curve for the final NMC811 product of Example 8.

[0094] Figure 47 shows an XRD pattern of the LMO'(CO2) material of Example 9. The circles in the figure show the positions of peaks identified to be from Mn3O4.

[0095] Figure 48 shows an XRD pattern of the final single crystal NMC811 product of Example 9.

[0096] Figure 49 shows SEM images of the final NMC811 product of Example 9.

[0097] Figure 50 shows EDS compositional maps of the final NMC811 product of Example 9.

[0098] Figure 51 shows the voltage curve of the first cycle for the final NMC811 product of Example 9.

[0099] Figure 52 shows the cycling performance of the final NMC811 product of Example 9.

[0100] Figure 53 shows the polarization curve for the final NMC811 product of Example 9.

[0101] Figure 54 shows an XRD pattern of (NMC811'+NMC622'+LCO'+LMO')(CO2) of Example 10 with peaks from Li2CO3, Ni, MnO, NiO, and CoO identified.

[0102] Figure 55 shows an XRD pattern of the final single crystal NMC811 product of Example 10.

[0103] Figure 56 shows SEM images of the final NMC811 product of Example 10.

[0104] Figure 57 shows EDS compositional maps of the final NMC811 product of Example 10.

[0105] Figure 58 shows the voltage curve of the first cycle for the final NMC811 product of Example 10.

[0106] Figure 59 shows the cycling performance of the final NMC811 product of Example 10.

[0107] Figure 60 shows the polarization curve for the final NMC811 product of Example 10. DETAILED DESCRIPTION

[0108] Embodiments herein relate to the recycling of cathode materials to produce new cathode materials with equivalent performance characteristics to state of the art cathode materials. Some embodiments herein relate to the recycling of one or more types of lithium ion cathode materials.

[0109] In some embodiments the used cathode materials are provided in a feedstock mixture with other used cathode materials, waste materials, or new metal sources. In some embodiments the active cathode materials (such as single crystal cathode materials) are not separated from inactive cathode materials (such as binders, separators, carbon, etc.) prior to the mixing. In some embodiments the active and inactive cathode materials are directly combined with other used cathode materials without any separation or purification steps.

[0110] Some embodiments of the disclosure relate to the recycling of used NCA′, LCO′, LMO′ or NMC′ materials to produce new LCO, LMO, NCA or NMC materials. In some embodiments the used cathode materials may be converted from one type of cathode material (having a first transition metal stoichiometry) to another type of cathode material (having a second transition metal stoichiometry). The used cathode material may be converted to a different type of cathode material through the incorporation of additional used cathode materials, waste materials, or new metal sources into a feedstock mixture. For example, used LMO′ may be converted to new NMC with the addition of nickel and cobalt either from used NMC′ or from the addition of new nickel and new cobalt compounds or oxides in the feedstock mixture. In some embodiments LCO′ may beconverted to new NMC with the addition of nickel and manganese either from used NMC′ or from nickel and manganese compounds or oxides in the feedstock mixture.

[0111] Some embodiments of the present disclosure provide a method of making single crystal cathode materials or NMC from used cathode materials, such as LCO′, LMO′ and one or more types of NMC′ of the same or different composition as the desired cathode or NMC product, and mixtures thereof.

[0112] Herein, one or more types of used or recovered cathode materials from used Li-ion batteries may be denoted with prime markers, such as LCO′, LMO′, NMC′, NMC111′, NMC622′, NMC811′ NCA′; which correspond to used LCO, LMO, NMC, NMC11, NMC622, NMC811 and NCA, respectively, that have been recovered from Li- ion batteries. In the embodiments disclosed herein, these one or more types of used cathode materials may contain residual or inactive components that are often used in battery cells, either from battery anodes or from battery cathodes. These common components include electrode coating and electrolyte, separators, binders (such as polyvinylidene difluoride (PVDF)), residual electrolyte solvents (such as ethylene carbonate (EC), fluoroethylene carbonate (FEC), vinylene carbonate (VC), and propylene carbonate (PC)), residual electrolyte salts (such as LiPF6), decomposition products formed by the reaction of used cathodes or electrolyte salts with the air (such as Li2CO3 and LiOH), and carbons, including carbon black, carbon nanotubes and graphite. Depending on the method used to recover the used cathode material, the used cathode materials may also contain components of the anode, including carbons such as graphite or binders used in the anode.

[0113] Other waste materials may be included in the recycling processes disclosed herein. For example, waste materials may be combined with one or more types of used cathode materials, new metal source powders or new cathode materials. The combining of these materials may be an all-dry process that does not involve the addition of external solvents or leaching solvents. The waste cathode materials may include: waste cathode powders that have never been used (e.g., waste fines from cathode production), waste electrode slurry, waste cathode scraps that have not been assembled into a cell and cathode powders from reject cells that have never been cycled.

[0114] A general flow chart depicting some embodiments of the disclosure is provided in Figure 1a. For example, Figure 1a generally depicts a process for recycling used battery cathode materials. Element 110a includes providing one or more used cathode materials. The one or more used cathode materials may be one or more types of cathode materials. Element 120a includes dry mixing the one or more used cathode materials withone or more new or used cathode materials or new metal sources to create a feedstock mixture. The used cathode materials may include a first type of a cathode material and a second type of a cathode material. Element 130a includes heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C. In Element 110a the used cathode materials may be used cathode materials recovered from used lithium-ion batteries comprising: LCO′, LMO′ and / or one or more types of NMC′. The used cathode materials in 110a may have a first transition metal stoichiometry and the and the synthesized cathode material after element 130a may have a second transition metal stoichiometry different from the first transition metal stoichiometry. The used cathode materials in 110a may include waste cathode materials or byproducts of cathode production.

[0115] Figure 1b is an additional flow chart for synthesizing a cathode material according to some embodiments herein. Step 110b includes providing one or more used cathode materials recovered from one or more battery cells, wherein the one or more used cathode materials have a first transition metal stoichiometry. Step 120b includes mixing the one or more used cathode materials with one or more new metal sources or used cathode materials in the absence of an added solvent to produce a feedstock mixture. Step 130b further includes heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C to produce the new lithium cathode material having a second transition metal stoichiometry different than the first transition metal stoichiometry. As a non-limiting example, the first stoichiometry may be LCO′ and the second stoichiometry may be NMC811. The mixing in Step 120b may be a dry mixing free of added solvents or water. In some embodiments the first transition metal stoichiometry of the one or more used cathode materials may differ from the second transition metal stoichiometry of the new lithium cathode material in at least one of lithium content the transition metal content (such as Ni, Mn, Co, Al, etc.) or the dopant content. In some embodiments the first transition metal stoichiometry may additionally differ from the second transition metal stoichiometry in lithium content. In some embodiments producing the new lithium cathode material comprises cooling the new lithium cathode material to a temperature below 100 °C or room temperature.

[0116] Figure 1c is an additional flow chart for synthesizing a cathode material according to some embodiments herein. Element 110c includes providing one or more used cathode materials recovered from one or more battery cells, wherein the one or more used cathode materials have a first transition metal stoichiometry. Element 120c includes heatingone or more of the used cathode materials (individually or in a mixture) in an initial CO2(g) atmosphere at a temperature greater than 300 °C to create a heated used cathode material. In some embodiments, this heating in an initial atmosphere interrupts or breaks down the crystal structure such that the heated used cathode material is comprised of separate metal oxides. Element 130c includes dry mixing the heated used cathode material or materials with one or more new or used cathode materials or new metal sources to create a feedstock mixture. The used cathode materials in the mixture may include a first type of a cathode material having the first transition metal stoichiometry, a second type of a cathode material having a second transitional metal stoichiometry different from the first transition metal stoichiometry and / or a third type of cathode material having a third transitional metal stoichiometry different from the first or second transition metal stoichiometries. A fourth, fifth or sixth type of used cathode material may be included, with a transition metal stoichiometry different than any of the other transition metal stoichiometries of the used cathode materials in the mixture. Element 140c includes heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C. In Element 110c, the used cathode materials may be used cathode materials recovered from used lithium-ion batteries comprising: LCO′, LMO′, and / or one or more types of NMC′. The used cathode materials in 110c may have a first transition metal stoichiometry and the synthesized cathode material after element 140c may have a second transition metal stoichiometry different from the first transition metal stoichiometry. The used cathode materials in 110c may include waste cathode materials or byproducts of cathode production.

[0117] Figure 1d is an additional flow chart for synthesizing a cathode material according to some embodiments herein. Element 110d includes providing one or more used cathode materials. The one or more used cathode materials may be one or more types of cathode materials having one or more transition metal stoichiometries. Element 120d includes dry mixing the one or more used cathode materials with one or more new or used cathode materials or new metal sources to create a feedstock mixture. The used cathode materials may include a first type of a used cathode material and a second type of a used cathode material. The mixture in 120d may be a plurality of used cathode materials and may not contain any new metal sources or new cathode materials. Element 130a includes heating the feedstock mixture in an initial CO2(g) containing atmosphere at a temperature greater than about 300 °C to create a heated feedstock mixture. An additional step, Element 135d, may include mixing the heated feedstock mixture with one or more new metalsources or new cathode materials after heating in the initial (CO2) atmosphere and excludes mixing the heated feedstock mixture with one or more used cathode materials after heating in the initial (CO2) atmosphere. Element 135d may be employed where the mixture 120d does not contain any new metal sources or new cathode materials. Element 140d includes heating the heated feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C. The oxygen containing atmosphere may consist of or consist essentially of elemental oxygen (O2). In Element 110d, the used cathode materials may be used cathode materials recovered from used lithium-ion batteries comprising: LCO′, LMO′ and / or one or more types of NMC′. Element 140d may additionally include dry mixing the heated feedstock mixture one or more used cathode materials with one or more new or used cathode materials or new metal sources prior to heating the heated feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C. The used cathode materials in 110d may have a first transition metal stoichiometry and the and the synthesized cathode material after the heating in element 140d may have a second transition metal stoichiometry different from the first transition metal stoichiometry. The used cathode materials in 110d may also include waste cathode materials or byproducts of cathode production.

[0118] In some embodiments the one or more used cathode materials may include a material having the formula Li[Mn1-gGg]2O4, where 0 ≤ g < 0.5 and G is a metal other than Mn, and is selected from the group consisting of Ni, Co, Cu, Al, Cr, Ti, and Mg. In some embodiments the one or more used cathode materials may include a cathode material having the formula LiMn2O4.

[0119] In some embodiments the one or more used cathode materials may include a material having the formula LiNidCoeAlfO2, where d + e + f = 1, d > 0.6, and 0.01 ≤ f ≤ 0.1.

[0120] In some embodiments the one or more used cathode materials may include a material having the formula Li1+x[(NinMnmCoc)1-aAa]1-xO2, where -0.03 ≤ x ≤ 0.06; n + m + c = 1; n / (n + m + c) > 0.3; m ≥ 0; c ≥ 0; A is a dopant; and 0 ≤ a ≤ 0.05. In some embodiments the one or more used cathode materials may be SC-NMC or the average NMC grain facet size is greater than 20% of the average particle size. The one or more used cathode materials may have an average particle size between 1 μm and 30 μm. The one or more used cathode materials may be NMC′ and have a high nickel content where x ≥ 0.6.

[0121] Some embodiments disclosed herein relate to a method of synthesizing an NMC cathode material that includes:(a) obtaining feedstock mixture components recovered from used lithium-ion batteries that include LCO′, LMO′ and / or one or more types of NMC′; (b) combining the feedstock mixture components into a feedstock mixture having the same transition metal and dopant atomic ratio as the desired cathode product; and (c) heating the feedstock mixture in an oxygen containing atmosphere at temperatures greater than about 700 °C.

[0122] In some embodiments the composition of the LCO′, LMO′ and NMC′ differs from that of the new NMC cathode material that is synthesized. In some embodiments more than about 10 wt% of the feedstock mixture is a used cathode material with a Ni, Mn or Co composition that differs from the composition of the synthesized NMC particulate. In some embodiments more than 5 wt% of the feedstock mixture has a transition metal composition (Ni, Mn or Co) that differs from the composition of the NMC cathode material that is synthesized. In some embodiments less than about 95 wt % of the feedstock mixture components are a used active cathode material with the same transition metal ratio as the desired stoichiometry in the synthesized NMC particulate product. In some embodiments less than 90 wt% of the feedstock mixture components are a used active cathode material with the same transition metal ratio as the desired stoichiometry in the synthesized NMC particulate product.

[0123] Some embodiments herein relate to a method for recycling cathode materials to obtain a new cathode material stoichiometry, the method comprising: providing one or more used cathode materials containing active and inactive materials; mixing the active and inactive materials with one or more new metal sources or used cathode materials to obtain a feedstock mixture, wherein the ratio of transition metals (including Ni, Mn and Co) in the feedstock mixture differs from that of the stoichiometry of the active materials in the used cathode material; and heating the feedstock mixture in an oxygen containing atmosphere at temperatures greater than 700 °C. The method may additionally comprise cooling the feedstock mixture to a temperature below about 50 °C to produce a recycled cathode material. In some embodiments there are no additional solvent- based purification or separation steps to separate the inactive and active components from the used cathode materials that are recovered from a used battery. In some embodiments the providing comprises providing a used battery, extracting the used cathode materials from the used battery, and directly combining the used cathode materials in a feedstock mixture. In some embodiments a sample or portion of the extracted used cathode materials may be analyzed to determine the composition of the used cathode materials. In someembodiments the recovering comprises mechanically separating the inactive and active materials from the current collector. The mixing of the used cathode materials in the feedstock mixture preferentially comprises dry mixing. In some embodiments the dry mixing comprises mixing with a paddle mixer, high shear mixer, a Henschel mixer, shaker mixer, a Loedige mixer, a Julia mixer, or a V-blender.

[0124] The methods disclosed herein are not limited to the method used to obtain the used cathode materials. Methods used to obtain the used cathode materials may include cell sorting, disassembly, shredding, leaching, washing, rinsing, crushing, heating, etc. In some embodiments the method used to obtain the used cathode materials is an all- dry process. In some embodiments the method used to obtain the used cathode materials does not separate the active cathode materials (for example NMC, LMO or LCO particles) from residual battery components such as used cathode materials separator components (e.g., polyethylene (PE) or polypropylene (PP)), and electrolyte and electrode components, including binders (such as polyvinylidene difluoride (PVDF)), residual electrolyte solvents (such as ethylene carbonate (EC), fluoroethylene carbonate (FEC), vinylene carbonate (VC), propylene carbonate (PC), and 1,3,2-dioxathiolane 2,2-dioxide (DTD)), residual electrolyte salts (such as LiPF6), decomposition products formed by the reaction of used cathodes or electrolyte salts with the air (such as Li2CO3 and LiOH), and carbons, including carbon black, carbon nanotubes and graphite. In some embodiments the method used to obtain the used cathode materials excludes metals and alloys from the cell casing / housing, tabs and current collectors (e.g., Fe, Ni, Al, Cu, stainless steel) from the used cathode materials. For example, the extraction of the cathode materials may be optimized such that cell casing / housing, tabs and current collectors are not included in the extracted used cathode materials or in the feedstock mixture.

[0125] In some embodiments the residual battery components, such as binders, separator components, electrolyte solvents and carbons, may be removed from the active cathode materials during heating or sintering. For example, the residual battery components may decompose during heating at temperatures up to or exceeding about 700 °C and are removed from the used cathode material during the heating. As such, the residual battery components or inactive battery components may not need to be removed from the used active cathode materials prior to the recycling. Therefore, the methods disclosed herein do not require the solvent-based removal of residual battery components or purification of the used cathode materials prior to combining with other used cathode materials or newtransitional metal sources. Therefore, the process may be an all-dry process that does not require leaching, extraction solvents or purification processes.

[0126] Without being bound to any theory, salts and / or residual battery components that do not decompose during the heating or firing process do not reduce the cell performance of the recycled battery cathode materials because they are compatible as battery components. For instance, in some embodiments lithium from residual electrolyte salt may beneficially become incorporated as active lithium in the new NMC cathode crystal structure. Further, certain elements may have a diameter that is not compatible with or incorporated into the O3 layered structure of NMC cathode materials. In some embodiments, such elements (e.g., Bi, W) may form an oxide during the heating process that beneficially coats the NMC cathode material grains and improves coulombic efficiency. In some embodiments, residual boron and flourine (such as from LiBF3), chloride (such as from LiClO4), sulfur (such as from LiTFSI and LiFSI), phosphorous (such as from LiPF6) may be included with the recycled cathode active materials in the all-dry recycling processes herein. In some embodiments these residual elements may be provided up to a certain threshold, such as up to less than about .1%, less than 1 wt%, less than 2 wt%, less than 5 wt%, less than 10 wt% of the feedstock mixture or any value or range of values in between (e.g.2-5 wt%).

[0127] In some embodiments at least about 50% of the impurities are removed from the feedstock mixture during the heating. In some embodiments at least about 75%, at least about 90% or at least about 99% of the impurities are removed from the feedstock mixture during the heating. The impurities may be removed through decomposition of the impurities into gases such as carbon dioxide, etc. The impurities may include inactive materials or materials that will not be incorporated into the synthesized battery cathode material. Some non-limiting examples of impurities are separator components, electrolyte solvent, electrolyte salt, binder, and carbon or graphite from the anode materials. In some embodiments a portion of these components, such as lithium in the electrolyte, may be incorporated into the synthesized cathode material.

[0128] The ratio of used to new materials in the feedstock mixture may range from about 10:90 to about 90:10 or any range in between (i.e., about 40:60, 50:50, 60:40, etc). In one embodiment the used cathode materials or cathode waste materials may comprise less than 50 wt% of the feedstock mixture. In some embodiments the used cathode materials or cathode waste materials comprise less than about 30 wt%, less than about 20 wt%, less than about 15 wt% or less than about 10 wt% of the feedstock mixture.

[0129] In some embodiments, the used cathode materials additionally contain separator components (e.g., polyethylene (PE) or polypropylene (PP)), electrolyte and electrode components, including binders (such as polyvinylidene difluoride (PVDF)), residual electrolyte solvents (such as ethylene carbonate (EC), fluoroethylene carbonate (FEC), vinylene carbonate (VC), propylene carbonate (PC), and 1,3,2-dioxathiolane 2,2- dioxide (DTD)), residual electrolyte salts (such as LiPF6), decomposition products formed by the reaction of used cathodes or electrolyte salts with the air (such as Li2CO3 and LiOH), and carbons, including carbon black, carbon nanotubes, and graphite. In such embodiments, the used cathode material is a multiphase mixture that contains used lithium transition metal oxides mixed with electrolyte and electrode components. The amounts of the separator and electrolyte and electrode components included is in principle not limited, since these components are either incorporated in the final NMC (e.g., lithium from the lithium containing components) or are removed during the heating step (c) in which carbons, binders, separator and electrolyte components react with oxygen and are eliminated as gaseous decomposition products. Therefore, the presence of separator and electrolyte and electrode components in the used cathode material is not detrimental to the final cathode or NMC product in the amounts that they typically are present in used cathode that is directly recovered from used Li-ion cells. In some embodiments the amount of electrolyte and electrode components or inactive materials present in the used cathode materials may be about 1%-20% by weight, 10%-20% by weight, 5%-10% by weight or 0%-5% by weight. In some embodiments substantial amounts of carbon may be present due to components of the anode from the used Li-ion cell being included with the used cathode materials during the process in which the used cathode material is recovered from the Li-ion cell. This carbon may be in the form of graphite, carbon black, and carbon nanotubes. In some embodiments the amount of carbon present in the used cathode materials may be about 1%- 60% by weight, 50%-60% by weight, 40%-50% by weight, 30%-40% by weight, 20%-30% by weight, 10%-20% by weight or 1%-10% by weight.

[0130] In some embodiments more than about 10 wt% of the feedstock mixture is a used cathode material with a Ni, Mn or Co composition that differs from the composition of the synthesized NMC particulate. The amount of used cathode material with a Ni, Mn or Co composition that differs from the composition of the synthesized NMC particulate may be adjusted in various embodiments: more than about 1%, more than about 5%, more than about 10%, more than about 15%, more than about 20%, more than about 25%, more than about 30%, more than about 40%, more than about 50%, more than about60%, more than about 70%, more than about 80% or any value of ranges in between. For example, between 20% and 25%. In some embodiments none or all of the transition metal composition in the used cathode material is the same as the transition metal composition in the synthesized cathode material product.

[0131] In some embodiments, the feedstock mixture components may include only one type of used cathode material (e.g., only LCO′, only LMO′, only NMC′ (of one NMC′ composition)). In some embodiments the feedstock mixture contains mixtures of LCO′, LMO′ and NMC′ (of different NMC compositions) in different combinations. In any case, a purpose of the disclosure herein is to enable a variety of different used cathode materials to be utilized in the manufacture of NMC. In some embodiments, less than 90 wt % of the feedstock mixture components consist of a used cathode material with the same transition metal ratio in its composition as the desired cathode or NMC product. In some embodiments, less than about 50 wt % of the feedstock mixture components consist of a used cathode material with the same transition metal ratio in its composition as the desired cathode or NMC product. In some embodiments, less than 10 wt % of the feedstock mixture components consist of a used cathode material with the same transition metal ratio in its composition as the desired cathode or NMC product. In some embodiments, none of the feedstock mixture components consist of a used cathode material with the same transition metal ratio in its composition as the desired cathode or NMC product.

[0132] In embodiments disclosed herein the transition metal composition in the feedstock mixture may differ from that of the synthesized cathode material. As disclosed herein, certain compositions of transition metals (such as LCO′, LMO′, NMC′) may be combined with other various types of used cathode materials. However, in some embodiments, some metals should be separated out or excluded from the feedstock mixture, including iron and copper. For example, the used cathode materials may be extracted from the battery cell without removal of the current collector, which may be comprised of copper. Therefore, some embodiments herein relate to a feedstock mixture wherein the feedstock mixture does not contain iron or copper. In some embodiments the feedstock mixture includes used cathode materials directly extracted with other battery components but excludes metals from the housing / casing or current collector. Therefore, in some embodiments the used cathode materials comprise any battery component (including anode materials) but excludes the battery housing, tabs or current collector.

[0133] In some embodiments, the amounts of transition metals that are not Ni, Mn or Co may be reduced below a threshold amount in the feedstock mixture. For example,the amounts of dopants such as W, Mg, Bi, V, Na, B, Al, Ti, Zn and Mo may be maintained below a particular threshold amount or separated out of the used cathode materials prior to the combining of the feedstock mixture.

[0134] In a preferred embodiment the synthesized cathode materials are single crystal cathode materials (abbreviated SC-NMC, as discussed above). In some embodiments the process may be used to produce polycrystalline NMC, abbreviated PC- NMC. In some embodiments the process may be used to convert PC-NMC to SC-NMC. In other embodiments the process may be used to convert PC-NMC to SC-NMC. PC-NMC may be synthesized, in part, with dry mixing methods such as micro-granulation. The micro-granulation methods that may be used in the processes herein are disclosed in WO 2021 / 040932, the entirety of which is incorporated by reference for any and all purposes.

[0135] In some embodiments, the feedstock mixture components include one or more of a Ni-source, a Co-source, a Mn-source or a Li-source. The Ni-source, Co-source, Mn-source or Li-source may be new metal sources, such as elemental metals, salts or compounds. The particle size of the Ni-source, Co-source, Mn-source or Li-source may be reduced via mixing or grinding, as disclosed herein. In some embodiments some or all of the Ni-source, Co-source and Mn-source are elemental metals. In some embodiments, the feedstock mixture components include one or more of a dopant element source. The dopant element source may be a new source that has not been incorporated into a battery cell, elemental metals, salts or compounds. Dopant elements can include Al, Ti, Zr, Zn, Mo, K, Na, Si, Ta, Mg, Cu, Ag, Cr, W, Nb, Sn, V, Bi and mixtures thereof. Suitable Ni-sources, Co-sources, Mn-sources, Li-sources and dopant element sources include metal oxide, metal carbonate and metal hydroxide powders. Suitable Ni-sources, Co-sources, Mn-sources and dopant element sources additionally include metal and alloy powders. Specific examples of Ni-sources include powders of Ni, NiO, NiCO3and Ni(OH)2. Specific examples of Co- sources include powders of Co, CoO, Co3O4, CoCO3 and Co(OH)2. Specific examples of Mn-sources include powders of Mn, MnO, Mn3O4, MnO2, MnCO3and Mn(OH)2. Specific examples of Li-sources include powders of LiOH, LiOH·H2O, Li2O, Li2CO3 and Li2O2. Specific examples of dopant element sources include powders of W, WO3, MgO, Bi, Bi2O3, V2O5, Na2O, NaOH, B2O3, Al2O3, NCA′, TiO2, ZnO, ZrO2, MoO3 and MoO2.

[0136] In preferred embodiments, the feedstock mixture components (used cathode materials and any new cathode materials or new metal sources) are in the form of powders. In some embodiments, combining the feedstock components into a feedstockmixture includes a grinding process in which the particle size of the one, some or all of the feedstock mixture components is reduced. In some embodiments the used cathode materials are subjected to a grinding process to reduce particle size. The grinding process may be performed individually with one, some or all of the feedstock mixture components, or with a mixture of some or all of the feedstock mixture components. Suitable grinding processes can be either “wet” or “dry”, however dry grinding processes are preferred and advantageous to enable an “all dry” process. Suitable grinding processes include grinding with an automatic grinder, grinding with a mortar and pestle, jet milling, ball milling, bead milling, small media milling, agitator ball milling, planetary milling, horizontal ball milling, pebble milling, rod milling, attritor milling, pulverizing, hammer milling, SPEX milling and vibratory milling. The small media milling may include microgranulation with milling media with average particle size less than 500 μm. Microgranulation may be useful to obtain polycrystalline cathode materials. In some embodiments, the grinding process results in a reduction of the particle size of some or all of the feedstock mixture components. In some embodiments, the feedstock mixture components do not react during the grinding process. In some embodiments, the feedstock mixture components react during the grinding process and form new phases.

[0137] In some embodiments it is desirable that the feedstock mixture is in the form of a powder with a small particle size. In some embodiments the average particle size of the feedstock mixture used in step (c) is between about 50 nm and 10 μm, 50 nm and 5 μm, 50 nm and 1 μm, or in exemplary embodiments between 50 nm and 0.5 μm.

[0138] In some embodiments combining the feedstock components into a feedstock mixture includes a heating process (called the “feedstock heating process” or “feedstock heating step”) in which some or all of the feedstock mixture components are heated in an initial atmosphere. This feedstock heating step may be used primarily or exclusively on used cathode materials (cathode materials for recycling). Further, the feedstock heating step may be performed in an atmosphere free or essentially free of elemental oxygen (O2). Such a feedstock heating step may, for instance, be undertaken to improve the compositional homogeneity of the feedstock mixture. In some embodiments, such a feedstock heating step is performed to transform one or more feedstock components (for example, used cathode materials) into a form that more readily reacts to form a new lithium cathode material in the step of heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C to produce the new lithium cathode material. Suitable atmospheres for a feedstock heating step include avacuum, inert gases (such as Ar or N2), reducing gases (such as H2 or H2 / Ar and H2 / N2 mixtures), CO2(g) and oxygen containing gases (such as air or O2). As an example of a feedstock heating step, the feedstock mixture components (for example, one or more used cathode materials) may be heated without a Li source in an inert gas to produce a rock salt phase oxide that is a solid solution of Ni, Mn and Co oxides. As another example of a feedstock heating step, a reducing gas may be employed to reduce some of the transition metals of the feedstock mixture components to their metallic form. In some embodiments, the feedstock heating atmosphere is a mixed atmosphere with gasses that are more reducing than atmospheric air. The heating may be performed at temperatures exceeding about 300 °C, about 500 °C, about 700 °C, about 800 °C, about 900 °C, about 1000 °C, about 1100 °C or any range of values in between (e.g., 800-900 °C). The temperature for heating may be varied throughout the heating process, such as that heating to a temperature greater than about 300 °C or greater than about 700 °C may include more than a single temperature value.

[0139] In some embodiments preparing the feedstock components in a feedstock mixture includes a feedstock heating process in which some or all of the feedstock mixture components are heated at a temperature exceeding 300 °C in a CO2(g) atmosphere. Without being bound by theory, it has been found that CO2(g) is a particularly good atmosphere for the feedstock heating step as it can convert Mn-containing feedstock component oxides into lower oxides that more readily react to form a new lithium cathode material in the subsequent step of heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C. In some embodiments it has been found that used cathode materials containing Mn can be transformed to Mn3O4and amorphous lithium and oxygen containing species, which can react more readily to form a new lithium cathode material in the subsequent step of heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C, compared to the reactivity of used cathode materials containing Mn, such as LMO' or NMC' that have not been subject to a feedstock heating step.

[0140] In some embodiments, obtaining feedstock mixture components includes a step in which the chemical composition of one or more feedstock components are determined. The composition of the one or more feedstock components may be determined prior to the combining or mixing of the feedstock components. One method of determining the chemical composition of a feedstock component is by inductively coupled plasma (ICP) analysis. The thus obtained composition of each feedstock component maythen be used to determine how much of each feedstock component needs to be included in the feedstock mixture. In some embodiments the determining of the chemical composition of the feedstock components or feedstock mixture may be performed more than one time. In some embodiments the composition of the feedstock mixture may be determined prior to heating in order to ensure the desired ratios of components prior to heating the cathode mixture. In some embodiments the composition of one or more used cathode materials may be unknown and the composition of the additional sources of metals or new metal sources are known. In some embodiments the composition of one used cathode material may be known but the composition of a second used cathode material to be included in the feedstock mixture is unknown. In some embodiments the composition of the transition metals and dopants in a used cathode material is known but the composition of lithium in one or more used cathode materials is unknown. In many cases determining the composition of the used cathode materials may be utilized to tailor, refine, or adjust the composition of the feedstock mixture. For example, a used cathode material may be provided where the composition is unknown. ICP may determine that the composition of the used cathode material is lithium manganese oxide (LMO). Therefore, a nickel and cobalt source may be provided. These sources may come from new nickel (such as Ni, NiO or mixtures thereof) or new cobalt (Co, CoO or mixtures thereof) or they may come from used NMC, which compositionally contains nickel and cobalt.

[0141] In some embodiments, the lithium content in the used cathode material may be unknown and determined by measuring the composition of the used NMC. In some embodiments the lithium composition in the used cathode materials may be unknown, but any deficiency can be provided or compensated for by utilizing excess new Li-source in the feedstock mixture. The unknown lithium composition may be unknown due to the unknown discharge state of the used battery from which it was recovered, such that a portion of the lithium ions reside in the anode, side reactions in with inactive components in the cell, the incorporation of an unknown quantity of lithium electrolyte salt in the used cathode material, the incorporation of an unknown quantity of lithiated anode material in the used cathode material or other reasons. The lithium may be provided in the feedstock mixture in excess at least partially to account for lithium loss (including evaporation) during heating of the feedstock mixture. As discussed below, the amount of excess lithium added to the feedstock mixture may be between about 1% and 40%.

[0142] In some embodiments, combining the feedstock components into a feedstock mixture includes a mixing process. Mixing processes can be either “wet” or “dry”,however dry mixing processes are preferred in the embodiments disclosed herein to enable an “all dry” cathode recycling process. This mixing process may be accomplished using mixing or blending equipment, including a paddle mixer, high shear mixer, a Henschel mixer, shaker mixer, a Loedige mixer, a Julia mixer or a V-blender. Especially desirable are dry mixing processes to reduce byproducts and solvent-based waste. In some embodiments the recycling process produces no or essentially no waste byproducts.

[0143] It is preferred that the feedstock mixture has a homogeneous distribution of used cathode material, Ni-source, Mn-source, Co-source and dopant element source powders. In some embodiments the arrangement of used cathode material, Ni-source, Mn- source, Co-source and dopant element source powders in the feedstock mixture is random on a scale less than 200 μm, less than 100 μm or more preferably less than 50 μm, less than 10 μm or even smaller. The homogeneous distribution of the feedstock mixture may be shown by EDS compositional mapping.

[0144] In some embodiments an excess of lithium is used in the combining step (b). Typical amounts of excess lithium are between about 1% and 40% in excess of the amount of lithium required to obtain the same lithium, transition metal and dopant atomic ratio as the desired cathode material product. In some embodiments the amount of excess lithium used is between 15% and 25% in excess of the amount of lithium required to obtain the same lithium, transition metal and dopant atomic ratio as the desired cathode material product, such as NMC. In some embodiments the amount of excess lithium used is between 10% and 15% in excess of the amount of lithium required to obtain the same lithium, transition metal and dopant atomic ratio as the desired cathode material, such as NMC. In some embodiments the amount of excess lithium used is between 1% and 10% in excess of the amount of lithium required to obtain the same lithium, transition metal and dopant atomic ratio as the desired cathode or NMC product.

[0145] In some embodiments, the method used is an all-dry process. In some embodiments the feedstock mixtures and synthesized cathode materials are free of solvents, solvent residues and aqueous residues. These residues include but are not limited to salts, acids, bases, trace metals and trace impurities. For example, conventional cathode leaching treatments may utilize HCl, HNO3, H2SO4, H3PO4 and organic acids such as citric, dl-malic, ascorbic, succinic, oxalic, l-tartaric, lactic acid and formic acids, which are solvent residues and are avoided herein. Other solvent residues may be trace metals, such as sodium, magnesium, calcium, iron, etc. Trace impurities may comprise residues incompletely removed from solvent reagents. These trace impurities may be acceptable according toindustry standards for the purity of certain reagents. These trace impurities may be in the amount of parts per million (ppm) or parts per billion (ppb). In some embodiments the process is free of molten salts.

[0146] In some embodiments the feedstock mixture transition metal and dopant atomic ratio Ni:Mn:Co:A is n:m:c:a, where n + m + c = 1, n ≥ 0.3, m ≥ 0.05, c ≥ 0 and 0 ≤ a ≤ 0.05. In some embodiments, n + m + c = 1, n ≥ 0.3, m ≥ 0.05, c ≥ 0.05 and 0 ≤ a ≤ 0.05. In some embodiments the dopant is selected from one or more elements in the group consisting of Al, Ti, Zr, Zn, Mo, K, Na, Si, Ta, Mg, Cu, Ag, Cr, W, Nb, Sn, V and Bi.

[0147] The raw powders mixture heating procedure includes heating the mixture in an oxygen containing atmosphere at a heating temperature that causes the used or spent cathode materials, a new nickel source, a new manganese source or a new cobalt source to react to form a final product, which may be NMC.

[0148] In some embodiments suitable heating temperatures include those that are greater than 700 °C. However, heating temperatures greater than 800 °C are more efficient. The heating temperature should not be too high, for instance greater than 1200 °C, as NMC can transfer to rock salt phase at such high temperatures. As a particular example, 880 °C can be a suitable heating temperature. The time the raw material mixture spends at the heating temperature can be determined by measuring the degree of cation mixing between the lithium and transition metal layers in NMC by x-ray powder diffraction at different times during the heating process and observing the NMC primary particle size by electron microscopy. The heating time should be maintained until the desired NMC crystal structure and primary particle size are obtained. In particular, a low degree of cation mixing between the Li and transition metal layers in NMC is preferred. In some embodiments, the degree of cation mixing between the Li and transition metal layers in NMC is less than 7%, less than 5%, less than 2% or less than 1%. An NMC primary particle size (in terms of D50) that is in the range of 0.1 μm to 20 μm is also preferred, with 2 μm to 10 μm or 1 μm to 5 μm being more preferred. In some embodiments, a heating time of 2 hours to 12 hours beyond the initial observation of the formation of the NMC phase by x- ray diffraction is used. As particular examples, 2 hours, 4 hours, 8 hours or 12 hours can be suitable heating times at a 880 °C heating temperature.

[0149] Oxygen containing atmospheres used in the heating the feedstock mixture step (c) should be selected such that the oxygen partial pressure is sufficient for the NMC phase to form. Examples of oxygen containing atmospheres suitable for the precursormixture heating procedure include O2(g), air or mixtures of oxygen with other gases, including inert gases such as N2(g), Ar(g) and other gases such as CO2.

[0150] The product may be a nickel manganese cobalt cathode material (NMC). Where the product is NMC, the product NMC contains an NMC phase having an O3 layered structure and may have the formula Li1+p[(NinMnmCoc)1-aAa]1-pO2, where -0.03 ≤ p ≤ 0.06; n + m + c = 1; n ≥ 0.3; m ≥ 0.05; c ≥ 0; A is a metal dopant; and 0 ≤ a ≤ 0.05. In some embodiments, the product NMC contains an NMC phase having an O3 layered structure and have the general formula Li1+p[(NinMnmCoc)1-aAa]1-pO2, where -0.03 ≤ p ≤ 0.06; n + m + c = 1; n ≥ 0.50; m ≥ 0.05; c ≥ 0.05; A is a metal dopant; and 0 ≤ a ≤ 0.05.

[0151] The product NMC can have different morphologies, depending on the heating temperature and heating time used in the raw material mixture heating procedure. In preferred embodiments, the product NMC is in the form of a powder. If the heating temperature used in the raw material mixture heating procedure is lower than 850 °C, the NMC tends to be in the form of a powder consisting mainly of polycrystalline secondary particles with the primary particles less than 1 μm in size. If the heating temperature used in the raw material mixture heating procedure is greater than 850 °C and the heating time used is greater than two hours, the NMC tends to be in the form of a powder consisting of single crystal primary particles that are greater than 1 μm in size.

[0152] In some embodiments, the product NMC comprises single crystal NMC. In some embodiments, the product NMC comprises single crystal NMC particles in which essentially each particle consists of multiple NMC grains. In preferred embodiments, the product NMC comprises single crystal NMC particles in which essentially each particle consists of a single NMC grain. In some embodiments, the cathode product has an average particle size between about 0.1 μm and 20 μm. In more preferred embodiments, the cathode or NMC product has an average particle sizebetween 2 μm and 10 μm.

[0153] The cathode product can additionally contain other phases. Phases that form a coating around the NMC phase grains are particularly useful. Such phases include lithiated oxides of tungsten, bismuth, and zirconium. However, to achieve high energy densities when used in a Li-ion cell, it is preferred that the product NMC is greater than 90% by weight NMC phase. In preferred embodiments, the product NMC is greater than about 95% by weight NMC phase, greater than 98% by weight NMC phase or greater than 99% by weight NMC phase. In some embodiments, the product NMC essentially consists of NMC phase.

[0154] Additional processing steps or post-processing can be applied to the cathode product or NMC. Deagglomeration processing can be particularly useful. Deagglomeration processes are those in which secondary product NMC particles are deagglomerated. They include those processes in which product NMC particles are deagglomerated into single crystal NMC in which essentially each particle consists of a single NMC grain. The machine used in deagglomeration process can include jet milling, ball milling, bead milling, small media milling, agitator ball milling, planetary milling, horizontal ball milling, pebble milling, rod milling or attritor milling. These can be wet or dry milling processes, but dry processes are preferred to maintain an all-dry process. Other additional processing steps can include washing the product NMC with a suitable solvent to remove surface lithium-containing species. Suitable solvents include water and ethanol. However, the deagglomeration or washing process can cause defects in the cathode product or NMC crystal structure. Therefore, an additional heating step(s) may be required after the deagglomeration or washing process to remove such defects. A new lithium source can be included in this additional heating step. Other additional processing steps can be the application of coatings on the surface of the product NMC particles. Examples of useful coatings include Al2O3, ZrO2 and TiO2.

[0155] The additional post-processing steps can be all-dry or substantially all- dry, including dry coating the synthesized cathode materials, dry mixing the synthesized cathode materials, refiring the cathode materials or subjecting the materials to an additional refiring after the dry coating of the cathode materials. The entire process, including the extraction of used cathode materials, mixing, synthesis and post-processing of the synthesized cathode materials may be dry and free of solvents. The entire process may be dry and performed in the absence of water or aqueous solvent. This is particularly beneficial as it reduces extensive amounts of wastewater and other byproducts involved in the purification and separation of used cathode materials. Since additional solvents and liquid reagents are not used the processes disclosed herein, the amount of energy and wastewater involved is reduced, including the energy required to synthesize these solvents and liquid reagents. Definitions

[0156] Although the following terms are believed to be well understood by one of skill in the art, the following definitions are set forth to facilitate understanding of the presently disclosed subject matter.

[0157] All technical and scientific terms used herein, unless otherwise defined below, are intended to have a meaning that would be understood by one of ordinary skill in the art. References to techniques employed herein are intended to refer to the techniques as commonly understood in the art, including variations on those techniques or substitutions of equivalent techniques that would be apparent to one of skill in the art.

[0158] As used herein, “transition metals” refer to elements in columns 3-12, rows 4-6 of the periodic table. Some examples of transition metals are Mn, Ni and Co. A transition metal stoichiometry is intended to refer to a proportion or ratio of one or more transition metals in a cathode material.

[0159] As used herein, a “molten salt” for a chemical reaction refers to those pure salts, salt mixtures or compounds which are in a liquid state in the absence of a solvent and which do not react with do not take part in the chemical reaction apart from being a medium for the diffusion of ions. Often molten salts are only liquid at elevated temperatures (e.g., at temperatures greater than 500 °C). Some examples of molten salts include NaCl, NaI, KCl and Na2SO4.

[0160] “Used cathode material(s)” should be given its ordinary meaning as would be understood by a person having ordinary skill in the art but often refers to cathode materials that have been previously discharged at least one time in a battery cell. Used cathode materials include materials that have been recovered from a battery cell and have not been subjected to chemical purification or separation processes. Used cathode materials may be cathode materials that have been discharged multiple times such that their discharge capacity is reduced. Used cathode materials may be designated herein with a prime number next to their abbreviation. For example, used NMC may be written NMC′ and used LMO may be written LMO′.

[0161] “Waste cathode materials” as used herein is meant to refer to cathode materials that are waste products or byproducts of battery production processes. Waste cathode materials may include: waste cathode powders that have never been used (e.g., waste fines from cathode production), waste electrode slurry, waste cathode scraps that have never been assembled into a cell and cathode powders from rejected cells that have never been cycled.

[0162] As used herein “new” material or “new metal source” refer to metal oxides, metal salts, elemental metals or other metal compounds that comprise no more than one metal element and are provided in a substantially pure or pure form. New metal sources may include substantially pure metal alloys that consist of more than one metal element.Examples of new metal sources include Li2CO3, Li2O, LiOH, Ni, NiO, NiOH, Mn, MnO, Mn2O3, MnO2, MnCO3, Mn(OH)2, Co, CoO, Co3O4, CoCO3, Co(OH)2, Ni-Mn alloys, Ni- Co alloys, Zr, ZrO2, Al, Al2O3, Mn-Co alloys and Ni-Mn-Co alloys. New metal sources have often been subjected to chemical or solvent-based purification and separation processes.

[0163] The term “solvents” or “added solvents” refers to liquid solvents that may be added to the mixture or synthesis process. The “absence of solvents” refers to a process that is performed without the addition of solvents in the synthesis process. Added solvents include solvents that were not extracted from the used battery materials. Therefore, electrolyte solvent, such as that extracted from a used cathode material, is not considered a “solvent” herein.

[0164] A “battery cell” should be given its ordinary meaning as would be understood by a person having ordinary skill in the art, but often refers to a battery having a battery anode and cathode for the discharge of electricity (or electrochemical potential) from the battery anode to the battery cathode. The battery may additionally include current collectors, a separator, electrolyte, additives and a flexible or rigid housing.

[0165] The term “feedstock materials” often refers to metal sources or additives included in a feedstock mixture. For example, in conventional production of LiNi0.6Mn0.2Co0.2O2the feedstock materials would be a source of lithium, a source of nickel, a source of manganese, and a source of cobalt. These feedstock materials may be substantially pure compounds (including salts) that comprise no more than one metal element or elemental metals or substantially pure metal alloys that consist of more than one metal element.

[0166] The term “impurities” as used to herein is intended to refer to elements not intended to be included in the new cathode material composition.

[0167] The term “separator components” as used herein should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art and generally refers to the material that separates the cathode and the anode in a battery cell. The separator is generally semi-permeable to allow the movement of ions (including lithium ions) between the anode and the cathode.

[0168] The term “stoichiometry” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art but often refers to the molar ratio of components. For example, NMC811 has a stoichiometric ratio written as LiNi0.8Mn0.1Co0.1O2 and NMC622 has a stoichiometric ratio written as LiNi0.6Mn0.2Co0.2O2.Similarly, a “type” of a cathode material generally refers to a particular transition metal stoichiometry. NMC622 and NMC811 are two different types of NMC.

[0169] The term “stochiometric amount” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art at the time of the disclosure but also refers to an amount of reactants in a chemical reaction that allows the reactants to react completely, based on the mole ratios indicated by the balanced chemical equation.

[0170] “Single crystal morphologies” or “single crystal” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art at the time of the disclosure but generally refers to refers to a crystalline solid where the particle consists essentially of one or more grains, where the average grain facet size is greater than 20% of the average particle size. In some embodiments of single crystal particles, each particle consists of a single crystal essentially free from interparticle boundaries.

[0171] The term “substantially free” or “essentially free” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art at the time of the disclosure but often refers to a minimal amount of something in a material. For example, in some embodiments substantially free means a material may contain an amount of something that does not materially affect the basic and novel characteristics of the materials involved.

[0172] The term “solvent residues” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art at the time of the disclosure but often refers to salts, acids, bases, trace metals, or trace impurities. Trace metals may include sodium, magnesium, calcium, iron, etc. Trace impurities may comprise residues incompletely removed from solvent reagents. These trace impurities may be present because they are acceptable according to industry standards for the purity of certain reagents. These trace impurities may be in amounts of parts per million (ppm) or parts per billion (ppb).

[0173] The term “dry” or “liquid-free environment” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art at the time of the disclosure but often refers to an environment that is free or substantially free of solvents including organic or aqueous solvents prior to the heating and melting of the materials. A “liquid-free environment” generally excludes solvents in liquid form but does not exclude solid hydrates, such as the solid hydrate LiOH-H2O.

[0174] The term “all-dry” refers to an entire process that is dry or free of liquids. All-dry includes a series of solid-state steps that are free of added liquids or solvents. The all-dry method may be dry even if it contains residual solvents from the used battery materials or if it includes the melting of a feedstock mixture component during a heating step, because no solvents or liquids are added.

[0175] The term “cathode” should be given its ordinary meaning as it would be understood by a person having skill in the art at the time of the disclosure and refers to the electrode at which reduction occurs when a metal-ion battery is discharged. In a lithium- ion cell, the cathode is the electrode that is lithiated during discharge and delithiated during charge. The cathode may also be called the “positive electrode.” Cathode materials such as NMC, LCO, LMO and NCA may be termed “active materials of the positive electrode” or “active cathode materials.”

[0176] As used herein, the term “active cathode material(s)” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art and is intended to refer to cathode materials that actively intercalates or deintercalates lithium in the cathode during the charging and discharging of the lithium ion battery. These include crystalline or polycrystalline cathode materials. The term “inactive” refers to materials in the cathode that do not intercalate or deintercalated lithium during the charging and discharging of the lithium ion battery. These may include, but are not limited to, electrolyte solvent, electrolyte salt, separators, binders and carbons, such as carbon black, carbon nanotubes, or graphite. Used anode materials recovered from the battery are not considered “active cathode materials” or “active materials” herein because they do not intercalate or deintercalate lithium in the cathode.

[0177] The term “average particle size” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art at the time of the invention but often refers to the average of the greatest dimension of at least 20 random particles as directly observed by a laser particle size analyzer or by electron microscopy.

[0178] The term “D50” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art at the time of the invention but often refers to the median particle size of a group of particles, as measured by a random group of particles.

[0179] The term “dopant” should be given its ordinary meaning as it would be understood by a person having ordinary skill in the art at the time of the disclosure but often refers to metals capable of serving as a dopant in a lithium transition metal oxide. In someinstances “dopant” includes the metals 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 but excludes the metals Li, Ni, Mn and Co. In some instances, “dopant” includes transition metals in elemental form, alloys, transition metal compounds, or non-transition metal compounds but excludes elements, alloys, or compounds whose constituent metal elements consist only of one or more of Li, Ni, Mn and Co.

[0180] The phrases “consisting essentially of” or “consists essentially of” are to be interpreted as limiting to the specified materials or steps involved (depending on context) but also to include – and not to exclude – any materials or steps that do not materially affect the basic and novel characteristics of the materials or steps involved.

[0181] The term “oxygen-containing atmosphere” is intended to refer to an atmosphere containing elemental oxygen in the form of the dioxygen molecule (O2).

[0182] As used herein, the term “and / or” refers to and encompasses any and all possible combinations of one or more of the associated listed items, as well as the lack of combinations when provided in the alternative (“or”).

[0183] As used herein, the terms “a” or “an” or “the” may refer to one or more than one. For example, “a” dopant can mean one dopant or a plurality of dopants. Examples

[0184] Some aspects of the embodiments discussed above are disclosed in further detail in the following examples, which are not in any way intended to limit the scope of the present disclosure. Those in the art will appreciate that many other embodiments also fall within the scope of the disclosure, as it is described herein above and in the claims. The following are exemplary in nature to better illustrate the present disclosure and are non-limiting in scope, application or uses.

[0185] Materials composition was determined by inductively coupled plasma - optical emission spectrometry (ICP-OES) (iCAP 7400 Dual View, Thermo Fischer Scientific, USA). Samples were digested in HNO3 using a Paar Multiwave 5000 microwave digestion unit. To determine the undetected mass, first the detected mass was determined by summing the masses associated with all the metal elements detected from ICP analysis, assuming that they are in the form of oxides. Then the undetected mass was calculated as the total sample mass minus the detected mass. This was then reported as a weight percent of the total sample mass. The undetected mass originates from impurities in the sample that were not detected by the ICP analysis, including organic substances (e.g., binder molecules,separator components, or electrolyte solvents), carbonaceous substances (e.g., carbon black and graphite), and carbonates and waters of hydration from residual lithium species on cathode surfaces.

[0186] Electrodes were made as follows. Polyvinylidene fluoride (PVDF, MW=534k, Sigma-Aldrich), n-methyl-2-pyrrolidone (NMP, Sigma-Aldrich), and carbon black (Super C65, Imerys) was mixed with a planetary mill for 3 h to make a stock solution. The stock solution was then mixed overnight in a rotary jar tumbler. Active material was added to this stock solution for a final weight ratio of 84:9.6:6.4 active cathode material:C65:PVDF with 37 wt% total solids in the slurry. For dispersion and deagglomeration, 4.1 g of this slurry was mixed in a 50 ml tungsten carbide vial, with 3 tungsten carbide balls (d=12 mm) using a planetary ball-mill (Retsch PM200) operating at 100 rpm for 2 h. The final slurry was applied to an aluminum foil with a 0.006" coating bar and dried at 120 °C under active vacuum overnight.

[0187] Electrochemical analysis was performed using CR2325 coin- configuration half-cells. Cell assembly was performed in an argon-filled glovebox. The counter / reference electrode was lithium metal foil (Sigma-Aldrich). Disk spacers that were 0.03" thick were placed under each electrode (cathode – aluminum spacer, lithium – copper spacer). A sheet of blown polypropylene microfiber (3M) and a sheet of trilayer porous polypropylene-polyethylene-polypropylene (Celgard 2325) were used as separators, with the trilayer separator on the lithium side. The electrolyte solution was 1 M lithium hexafluorophosphate in ethylene carbonate: diethyl carbonate: fluoroethylene carbonate 3:6:1vol (BASF), added to the cell in large excess.

[0188] Cell cycling was performed using a Neware Battery Testing System at 30 °C. The first cycle was performed at a C / 20 rate and all following cycles at C / 5, in a voltage range of 2.5-4.3V. C-rate was calculated from active material weight assuming a 200 mAh / g capacity. In all cycles, at the end of cathode delithiation (charge), a constant 4.3 V voltage was maintained until current dropped to half of the cycling rate (C / 40 or C / 10). Specific capacity is reported in terms of active powder mass (rather than full electrode mass) Example 1

[0189] To obtain used cathode material LCO′, a full LCO cell from a laptop battery (HP 493976-0018-cell lithium-ion 2.55 Ah) that had been in use for three yearswas disassembled. The LCO′ was then recovered by scraping off the recovered cathode coating from its current collector with a razor blade. The contents of elements in the LCO′ sample as detected by ICP analysis are listed in Tables 3a and 3b. Also listed is the undetected mass of the sample. The collected LCO′ powder was not washed or rinsed, therefore the LCO′ also contained residual binder, carbon black, electrolyte solvent, and salt. This is reflected in the relatively high undetected mass value of 10.14 wt% for the LCO′ sample. The Li:Co atomic ratio of the collected LCO′ powder was determined by ICP analysis to be 9:10, which indicates that the LCO contained in the LCO′ was 10% lithium deficient in comparison to the stoichiometric formula LiCoO2 of LCO. Thereafter, 2 g of the LCO′ was dry ball milled using a SPEX 8000D Mixer / Mill (SPEX Certiprep) at 900 rpm for 2 h with 80 g of 1.6 mm diameter ZrO2 balls to reduce the LCO′ average particle size from about 10 μm to about 0.5 μm. Thereafter 0.245 g of the milled LCO′, 1.174 g of a new Ni source (Ni metal powder, 0.5 μm, Vale), 0.19 g of a new Mn source (Mn3O4, 97%, -400 mesh, Vibrantz ) and 1.025 g of a new lithium source (Li2CO3, 99.7%, -400 mesh, Alfa Aesar) were then ground in the absence of solvents using an automatic mortar grinder (Retsch RMO) for 3 h. The resulting feedstock mixture had a Ni:Mn:Co molar ratio of 8:1:1 and a lithium content that was 20 atomic% in excess of the desired final LiNi0.8Mn0.1Co0.1O2(NMC811) stoichiometry. The feedstock mixture was observed by EDS (Energy Dispersive Spectroscopy) mapping to be a random distribution of feedstock mixture components within a 2 μm scale. The feedstock mixture was then placed in an alumina crucible and heated in a tube furnace from room temperature to 880 °C at a rate of 5 °C / min and then held at a temperature of 880 °C for 12 h under flowing oxygen atmosphere. Under continuous flowing oxygen atmosphere the furnace was then allowed to naturally cool to below 100 °C. The resulting product was NMC with a stoichiometry of LiNi0.8Mn0.1Co0.1O2. The product was then dry ground by mortar and pestle. The composition of the NMC product as determined by ICP analysis is listed in Tables 3a and 3b. The NMC composition is consistent with the desired NMC811 stoichiometry. Moreover, the undetected mass of the sample is only 1.39%, which is much smaller than the undetected mass in the LCO′ powder. This shows that more than 50% of the undetected species in the LCO′ powder (from impurities including binder, carbon black, etc.) have been removed during the synthesis process.

[0190] Figure 2 shows an XRD (x-ray diffraction) pattern of the final NMC811 product of Example 1. The sample is pure NMC811 phase with the O3 structure, indicatingfull conversion of the feedstock mixture to single crystal NMC811. From the XRD pattern, values of the lattice constants, cation mixing degree, and Bragg R value were obtained by Rietveld refinement are listed in Table 1.

[0191] Table 1 shows lattice constants, cation mixing degree and Bragg R obtained by Rietveld refinement of NMC811 in Example 1. Table 1 Example a c Cation Mixing Bragg R (Å) (Å) (%) [019duct of Example 1. The final NMC811 product is in the form of a powder with primary particle sizes in the range of 0.1-10 μm and secondary particle sizes of about 5-10 μm.

[0193] Figure 4 shows EDS compositional maps of the final NMC811 product of Example 1. The final NMC811 product shows homogeneous distribution of transition metals to within 0.1 μm resolution.

[0194] Table 2 shows the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100. Table 2 Example Discharge capacity Discharge capacity ICE Polarization 1

[0195] Figure 5 shows the voltage curve of the first cycle for the final NMC811 product of Example 1.

[0196] Figure 6 shows the cycling performance curve for the final NMC811 product of Example 1.

[0197] Figure 7 shows the polarization curve for the final NMC811 product of Example 1.

[0198] Tables 3a and 3b show the ICP results of all components in LCO′ and the final product NMC811 of Example 1. Table 3a SampleMain Elements Undetected MassLi Ni Mn CoSample NMC811 (wt%)LCO ′ (wt%)Example 2

[0199] To obtain used cathode material LMO′, a full LMO pouch cell (obtained from NOVONIX) that had undergone at least 100 charge / discharge cycles was disassembled. The cathode coating from the recovered cathode was then scraped off its collector with a razor blade. The thus collected LMO′ powder contained 4 wt% carbon black and 2 wt% PVDF binder. The electrode was not washed, therefore the LMO′ also contained residual electrolyte, solvent, and salt. The contents of elements in the LMO′ sample as detected by ICP analysis are listed in Tables 6a and 6b. Also listed is theundetected mass of the sample. The Li:Mn atomic ratio of the collected LMO′ powder was determined by ICP analysis to be 64:100, which indicates that the LMO contained in the LMO′ was in a 28% excess in comparison to the stoichiometric formula LiMn2O4 of LMO. This indicates the presence of Li from residual electrolyte and electrolyte decomposition products. Thereafter 2 g of the LMO′ was dry ball milled using a SPEX 8000D Mixer / Mill (SPEX Certiprep) at 900 rpm for 2 h with 80 g of 1.6 mm diameter ZrO2 balls to reduce the LMO average particle size from about 8 μm to 0.5 μm. Thereafter, 0.226 g of the milled LMO′, 1.174 g of a new Ni source (Ni metal powder, 0.5 μm, Vale), 0.2 g of a new Co source (Co3O4, 97%, -400 mesh, Freeport Cobalt) and 1.16 g of a new lithium source (Li2CO3, 99.7%, -400 mesh, Alfa Aesar) were ground in the absence of external solvents using an automatic mortar grinder (Retsch RMO) for 3 h. The resulting feedstock mixture had a Ni:Mn:Co molar ratio of 8:1:1 and a lithium content that was 30 atomic% in excess of the desired final LiNi0.8Mn0.1Co0.1O2 stoichiometry. The feedstock mixture was observed by EDS mapping to be a random distribution of feedstock mixture components within a 2 μm scale. The feedstock mixture was then placed in an alumina crucible and heated in a tube furnace from room temperature to 880 °C at a rate of 5 °C / min and then held at a temperature of 880 °C for 12 h under flowing oxygen atmosphere. Under continuous flowing oxygen atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The resulting product was NMC with a stoichiometry of LiNi0.8Mn0.1Co0.1O2. The product was then dry ground by mortar and pestle. The composition of the NMC product as determined by ICP analysis is listed in Tables 6a and 6b. The NMC composition is consistent with the desired NMC811 stoichiometry. Moreover, the undetected mass of the sample is only 1.03%, which is much smaller than the undetected mass in the LMO′ powder. This shows that more than 50% of the undetected species in the LMO′ powder (from impurities including binder, carbon black, etc.) have been removed during the synthesis process.

[0200] Figure 8 shows an XRD pattern of the final single crystal NMC811 product of Example 2. The sample is pure NMC811 phase with the O3 structure, indicating full conversion of the feedstock mixture to NMC811. From the XRD pattern, values of the lattice constants, cation mixing degree, and Bragg R value were obtained by Rietveld refinement are listed in Table 4.

[0201] Table 4 shows lattice constants, cation mixing degree and Bragg R obtained by Rietveld refinement of NMC811 in Example 2.Table 4 Example a c Cation Mixing Bragg R (Å) (Å) (%) 2 2874 14205 289 230 [020duct of Example 2. The final NMC811 product is in the form of a powder with primary particle sizes in the range of 0.1-10 μm and secondary particle sizes of about 5-10 μm.

[0203] Figure 10 shows EDS compositional maps of the final NMC811 product of Example 2. The final NMC811 product shows homogeneous distribution of transition metals to within 0.1 μm resolution.

[0204] Table 5 shows the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100. Table 5 Example Discharge capacity Discharge capacity ICE Polarization at cycle 1 at cycle 100 (%) at cycle 1

[0005] gure s ows e vo age curve o e rs cyc e or e final NMC811 product of Example 2.

[0206] Figure 12 shows the cycling performance curve for the final NMC811 product of Example 2.

[0207] Figure 13 shows the polarization curve for the final NMC811 product of Example 2.

[0208] Tables 6a and 6b show the ICP results of all components in LMO′ and the final product NMC811 of Example 2.Table 6a SampleMain Elements Undetected MassLi Ni Mn CoSample NMC811(wt%) LMO′ (wt%) Example 3

[0209] To obtain used cathode material NMC811′ and NMC622′, a full NMC811 pouch cell and a full NMC622 pouch cell (both provide by NOVONIX) that had undergone at least 100 charge / discharge cycles were disassembled. The cathode coatings from the recovered cathodes were then scraped off their respective current collectors with a razor blade. The collected NMC811′ and NMC622′ powders contained 4 wt% carbon black and 2 wt% PVDF binder. The electrodes were not washed, therefore the NMC811′ and NMC622′ also contained residual electrolyte solvent and salt. The composition of the NMC811′ and NMC622′ were determined by ICP. The contents of elements in the NMC811′ and NMC622′ samples as detected by ICP analysis are listed in Tables 9a and 9b. Also listed are the undetected masses of the sample. According to ICP results, NMC811′had 6% Li deficiency and NMC622′ had 0% of Li deficiency.0.977 g of NMC811′, 0.976 g of NMC622′, 0.46 g of a new Ni source (Ni metal powder, 0.5 μm, Vale), and 0.653 g of a new lithium source (Li2CO3, 99.7%, -400 mesh, Alfa Aesar) were then dry mixed and ball milled in the absence of external solvents using a SPEX 8000D Mixer / Mill (SPEX Certiprep) at 900 rpm for 4 h with 80 g of 1.6 mm diameter ZrO2 balls to reduce their average particle size from about 5 μm to 0.5 μm. The resulting feedstock mixture had a Ni:Mn:Co molar ratio of 8:1:1 and a lithium content that was 35 atomic% in excess of the desired final LiNi0.8Mn0.1Co0.1O2stoichiometry. The feedstock mixture was observed by EDS mapping to be a random distribution of feedstock mixture components on a scale less than 2 μm. The feedstock mixture was then placed in an alumina crucible and heated in a tube furnace from room temperature to 880 °C at a rate of 5 °C / min and then held at a temperature of 880 °C for 12 h under flowing oxygen atmosphere. Under continuous flowing oxygen atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The resulting product was single crystal NMC811 with a stoichiometry of LiNi0.8Mn0.1Co0.1O2. The product was then dry ground by mortar and pestle. The composition of the NMC product as determined by ICP analysis is listed in Tables 9a and 9b. The NMC composition is consistent with the desired NMC811 stoichiometry. Moreover, the undetected mass of the sample is only 5.02%, which is much smaller than the undetected mass in the NMC811′ and NMC622′ powders. This shows that more than 50% of the undetected species in the NMC811′ and NMC622′ powders (from impurities including binder, carbon black, etc.) have been removed during the synthesis process.

[0210] Figure 14 shows an XRD pattern of the final NMC811 product of Example 3. The sample is pure NMC811 phase with the O3 structure, indicating full conversion of the feedstock mixture to NMC811. From the XRD pattern, values of the lattice constants, cation mixing degree, and Bragg R value were obtained by Rietveld refinement are listed in Table 7.

[0211] Table 7 shows lattice constants, cation mixing degree and Bragg R obtained by Rietveld refinement of NMC811 in Example 3. Table 7 Example a c Cation Mixing Bragg R Å Å

[0212] Figure 15 shows SEM images of the final NMC811 product of Example 3. The final NMC811 product is in the form of a powder with primary particle sizes in the range of 0.1-10 μm and secondary particle sizes of about 5-10 μm.

[0213] Figure 16 shows EDS compositional maps of the final NMC811 product of Example 3. The final NMC811 product shows homogeneous distribution of transition metals to within 0.1 μm resolution.

[0214] Table 8 shows the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100. Table 8 Example Discharge capacity Discharge capacity ICE Polarization at cycle 1 at cycle 100 (%) at cycle 1g g y final NMC811 product of Example 3.

[0216] Figure 18 shows the cycling performance curve for the final NMC811 product of Example 3.

[0217] Figure 19 shows the polarization curve for the final NMC811 product of Example 3.

[0218] Tables 9a and 9b show the ICP results of all components in NMC811′, NMC622′ and the final product NMC811 of Example 3. Table 9a SampleMain Elements Undetected MassTable 9b Sample NMC811 (wt%) NMC811′ (wt%) NMC622′ (wt%)xamp e

[0219] In this example LCO′ from Example 1, LMO′ from Example 2 and NMC811′ and NMC622′ from Example 3 were used. Specifically, 0.489 g of LCO′ from Example 1, 0.452 g of LMO′ from Example 2, 0.977 g of NMC811′ from Example 3, 0.732 g of NMC622′ from Example 3 and 2.65 g of a new Ni source (Ni metal powder, 0.5 μm, Vale) were then dry mixed and ground in the absence of solvents using an automatic mortar grinder (Retsch RMO) for 3 h. The resulting feedstock mixture components had an overall Ni:Mn:Co molar ratio of 8:1:1. These feedstock mixture components were observed by EDS mapping to be a random distribution of feedstock mixture components within a 2 μm scale. These feedstock mixture components were then placed in an alumina crucible and heated in a tube furnace from room temperature to 880 °C at a rate of 5 °C / min and then held at a temperature 880 °C for 12 h under air atmosphere. Under air atmosphere, the furnace was then allowed to naturally cool to below 100 °C. An XRD pattern of the resulting product is shown in Figure 20. All the XRD peaks correspond to a rock salt phase, excepting a small peak at about 18°. This shows that the resulting product was essentially a rock salt phase. The product was then dry ground by mortar and pestle with 2.365 g of a new lithium source (Li2CO3, 99.7 %, -400 mesh, Alfa Aesar). This feedstock mixture was then dry ground using an automatic mortar grinder (Retsch RMO) for 15 min. The resultingfeedstock mixture had a lithium content that was 20 atomic% in excess of the desired final LiNi0.8Mn0.1Co0.1O2stoichiometry. The feedstock mixture was then placed in an alumina crucible and heated in a tube furnace from room temperature to 880 °C at a rate of 5 °C / min and then held at a temperature of 880 °C for 12 h under flowing oxygen atmosphere. Under flowing oxygen atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The resulting product was single crystal NMC with a stoichiometry of LiNi0.8Mn0.1Co0.1O2. The product was then ground by mortar and pestle. The composition of the NMC product as determined by ICP analysis is listed in Tables 12a and 12b. The NMC composition is consistent with the desired NMC811 stoichiometry. Moreover, the undetected mass of the sample is 0 %, which is much smaller than the undetected mass in the LMO′, LCO′ and NMC811′ powders. This shows that about 100% of the undetected species in the LMO′, LCO′ and NMC811′ powders (from impurities including binder, carbon black, etc.) have been removed during the synthesis process.

[0220] Figure 20 shows an XRD pattern of the rock salt phase formed after first step heating.

[0221] Figure 21 shows an XRD pattern of the final NMC811 product of Example 4. The sample is pure NMC811 phase with the O3 structure, indicating full conversion of the feedstock mixture to NMC811. From the XRD pattern, values of the lattice constants, cation mixing degree, and Bragg R value were obtained by Rietveld refinement are listed in Table 10.

[0222] Table 10 lattice constants, cation mixing degree and Bragg R obtained by Rietveld refinement of NMC811 in Example 4 Table 10 Example a c Cation Mixing Bragg R Å Å %

[0223] Figure 22 shows SEM images of the final NMC811 product of Example 4. The final NMC811 product is in the form of a powder with primary particle sizes in the range of about 0.1-10 μm and secondary particle sizes of about 5-10 μm.

[0224] Figure 23 shows EDS compositional maps of the final NMC811 product of Example 4. The final NMC811 product shows homogeneous distribution of transition metals to within 0.1 μm resolution.

[0225] Table 11 shows the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100. Table 11 Example Discharge capacity Discharge capacity ICE Polarization at cycle 1 at cycle 100 (%) at cycle 1final NMC811 product of Example 4.

[0227] Figure 25 shows the cycling performance curve for the final NMC811 product of Example 4.

[0228] Figure 26 shows the polarization curve for the final NMC811 product of Example 4.

[0229] Tables 12a and 12b show the ICP results of all components in the final product NMC811 of Example 4. Table 12a SampleMain Elements Undetected MassTable 12b NMC811 (wt%)Al 0.13Example 5

[0230] The cathode material NMC811′ and NMC622′ from Example 3 were used in this example.0.977 g of NMC811′, 0.976 g of NMC622′, 0.46 g of a new Ni source (Ni metal powder, 0.5 μm, Vale), 0.653 g of a new lithium source (Li2CO3, 99.7%, -400 mesh, Alfa Aesar) and 0.976 g of graphite (MAGE Artificial Graphite) were dry mixed and ball milled in the absence of external solvents using a SPEX 8000D Mixer / Mill (SPEX Certiprep) at 900 rpm for 2 h with 80 g of 1.6 mm diameter ZrO2 balls to reduce their average particle size from about 5 μm to 0.5 μm. The resulting feedstock mixture had a Ni:Mn:Co molar ratio of 8:1:1 and a lithium content that was 35 atomic% in excess of the desired final LiNi0.8Mn0.1Co0.1O2stoichiometry. The feedstock mixture was observed by EDS mapping to be a random distribution of feedstock mixture components on a scale less than 2 μm. The feedstock mixture was then placed in an alumina crucible and heated in a tube furnace from room temperature to 600 °C at a rate of 5 °C / min and held for 8 h. Then the temperature increased to 880 °C at the same rate and held for 12 h. The whole process was under flowing oxygen atmosphere. Under continuous flowing oxygen atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The resulting product was single crystal NMC811 with a stoichiometry of LiNi0.8Mn0.1Co0.1O2. The product was then dry ground by mortar and pestle. The ICP results of all components in the final product NMC811 are shown in Table 15. The NMC composition is consistent with the desiredNMC811 stoichiometry. Moreover, the undetected mass of the sample is 1.41 %, which is much smaller than the graphite content of the feedstock mixture (24 wt.%) and the undetected mass in the NMC811′ and NMC622′ powders. This shows that most (> 94 %) of the graphite impurity and the undetected species in the NMC811′ and NMC622′ powders (from impurities including binder, carbon black, etc.) have been removed during the synthesis process.

[0231] Figure 27 shows an XRD pattern of the final NMC811 product of Example 5. The sample is pure NMC811 phase with the O3 structure, indicating full conversion of the feedstock mixture to NMC811. From the XRD pattern, values of the lattice constants, cation mixing degree, and Bragg R value were obtained by Rietveld refinement are listed in Table 13.

[0232] Table 13 lattice constants, cation mixing degree and Bragg R obtained by Rietveld refinement of NMC811 in Example 5. Table 13 Example a c Cation Mixing Bragg R (Å) (Å) (%) [0233gu e s o s ages o e a p oduct of Example 5. The final NMC811 product is in the form of a powder with primary particle sizes in the range of 0.1-10 μm and secondary particle sizes of about 5-10 μm.

[0234] Figure 29 shows EDS compositional maps of the final NMC811 product of Example 5. The final NMC811 product shows homogeneous distribution of transition metals to within 0.1 μm resolution.

[0235] Table 14 shows the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100. Table 14 Example Discharge capacity Discharge capacity ICE Polarization t l 1 t l 1 t l 1

[0236] Figure 30 shows the voltage curve of the first cycle for the final NMC811 product of Example 5.

[0237] Figure 31 shows the cycling performance curve for the final NMC811 product of Example 5.

[0238] Figure 32 shows the polarization curve for the final NMC811 product of Example 5.

[0239] Table 15 shows the ICP results of all components in the final product NMC811. Table 15 SampleMain Elements Undetected MassLi Ni Mn CExample 6

[0240] To obtain used cathode material LMO', a full LMO pouch cell (obtained from NOVONIX) that had undergone at least 100 full charge / discharge cycles was disassembled. The cathode coating from the recovered cathode was then scraped off its current collector with a razor blade. The collected LMO' powder contained 4 wt% carbon black and 2 wt% PVDF binder. The electrode was not washed, therefore the LMO′ also contained residual electrolyte, solvent, and salt. The contents of elements in the LMO′ sample as detected by ICP analysis are listed in Tables 18a and 18b. Also listed in Table 18a is the undetected mass of the LMO' sample.

[0241] Table 18a Li, Ni, Mn, and Co content (all in wt%) by ICP analysis of LMO' of Example 6 and the final product NMC811 of Examples 7-9. Also listed is the undetected mass in these samples (all in wt%). ExampleMain Elements Undetected MassSample Li Ni Mn Co

[0242] Table 18b Trace element content by ICP analysis (all in wt%) of the LMO' from Example 6 and the final product NMC811 of Examples 7-9. Sample Trace Element LMO' NMC811 NMC811 NMC811

[0243] The Li:Mn atomic ratio of the collected LMO powder was determined by ICP analysis to be 64:100, which indicates that the Li contained in the LMO' was in a 28 atomic% excess in comparison to the stoichiometric formula LiMn2O4of LMO. This indicates the presence of Li from residual electrolyte and electrolyte decomposition products. This excess Li was utilized as a Li source during the synthesis. An XRD pattern of the LMO' is shown in Figure 33. It has XRD peaks corresponding to a single-phase LiMn2O4spinel structure. Example 7

[0244] In Example 7, the LMO' from Example 6 was ground in the absence of external (added) solvents using an automatic mortar grinder (Retsch RMO) for 1h to reduce its average particle size from about 8 μm to 1 μm. Thereafter, 0.226 g of the LMO′ from Example 6, 1.174 g of a new Ni source (Ni metal powder, 0.5 μm, Vale), 0.2 g of a new Co source (Co3O4, 97%, -400 mesh, Freeport Cobalt), and 1.16 g of a new lithium source(Li2CO3, 99.7%, -400mesh, Alfa Aesar) were ground in the absence of external solvents using an automatic mortar grinder for 3h. The resulting feedstock mixture had a Ni:Mn:Co molar ratio of 8:1:1 and a lithium content that was 20 atomic% in excess of the desired final LiNi0.8Mn0.1Co0.1O2stoichiometry. The feedstock mixture was observed by EDS mapping to be a random distribution of feedstock mixture components within a 2 μm scale. The feedstock mixture was then placed in an alumina crucible and heated in a tube furnace from room temperature to 880 °C at a rate of 5 °C / min and then held at a temperature of 880 °C for 12 h under flowing oxygen atmosphere. Under continuous flowing oxygen atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The resulting product was NMC with a stoichiometry of LiNi0.8Mn0.1Co0.1O2. The product was then dry ground by mortar and pestle. The composition of the resulting final NMC product as determined by ICP analysis is listed in Tables 18a and 18b. The NMC composition is consistent with the desired NMC811 stoichiometry. Moreover, the undetected mass of the sample (also in Table 18a) is only 1.87%, which is much smaller than the undetected mass in the LMO′ powder.

[0245] Figure 34 shows an XRD pattern of the final single crystal NMC811 product of Example 7. The sample is pure NMC811 phase with the O3 structure, indicating full conversion of the feedstock mixture to NMC811. From the XRD pattern, values of the lattice constants, cation mixing degree, and Bragg R value were obtained by Rietveld refinement, and are listed in Table 19.

[0246] Table 19 lattice constants, cation mixing degree, and Bragg R obtained by Rietveld refinement of the product NMC811 of Examples 7-9. Example a c Cation Mixing Bragg R

[0247] Figure 35 shows SEM images of the final NMC811 product of Example 7. The final NMC811 product is in the form of a powder with primary particle sizes in the range of 0.1-10 μm and secondary particle sizes of about 4-8 μm.

[0248] Figure 36 shows EDS compositional maps of the final NMC811 product of Example 7. This shows that the final NMC811 product has a homogeneous distribution of transition metals to within 0.1 μm resolution.

[0249] The final NMC811 product was incorporated into coin-half cells for electrochemical analysis. Table 20 shows the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100 of the final NMC811 product of Example 7.

[0250] Table 20 the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100 of the final NMC811 products of Example 7-9. Example Discharge capacity Discharge capacity ICE Polarization 1

[0251] Figure 37 shows the voltage curve of the first cycle for the final NMC811 product of Example 7.

[0252] Figure 38 shows the cycling performance curve for the final NMC811 product of Example 7.

[0253] Figure 39 shows the polarization curve for the final NMC811 product of Example 7.Example 8

[0254] In Example 8, the LMO' of Example 6 was processed using a feedstock heating step by placing 2 g of the LMO' in an alumina crucible and heating it in a tube furnace from room temperature to 600 °C at a rate of 5 °C / min and holding it at 600 °C for 2 h, all under flowing Ar / H2 atmosphere. Under continuous flowing Ar / H2 atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The material resulting from this heating of LMO' in Ar / H2(g) is henceforth referred to LMO'(H2). An XRD pattern of LMO'(H2) is shown in Figure 40. During the heating the spinel structure of LMO' has been reduced to MnO and Ni.

[0255] The LMO'(H2) was then ground in the absence of external (added) solvents using an automatic mortar grinder (Retsch RMO) for 1h to reduce its average particle size from about 5-8 μm to 1 μm. Thereafter, 0.323 g of the ground LMO'(H2), 1.642 g of a new Ni source (Ni metal powder, 0.5 μm, Vale), 0.271 g of a new Co source (Co3O4, 97%, -400 mesh, Freeport Cobalt), and 1.6 g of a new lithium source (Li2CO3, 99.7%, -400 mesh, Alfa Aesar) were ground in the absence of external solvents using an automatic mortar grinder for 3h. The resulting feedstock mixture had a Ni:Mn:Co molar ratio of 8:1:1 and a lithium content that was 20 atomic% in excess of the desired final LiNi0.8Mn0.1Co0.1O2 stoichiometry. The feedstock mixture was observed by EDS mapping to be a random distribution of feedstock mixture components within a 2 μm scale. The feedstock mixture was then placed in an alumina crucible and heated in a tube furnace from room temperature to 880 °C at a rate of 5 °C / min and then held at a temperature of 880 °C for 12 h under flowing oxygen atmosphere. Under continuous flowing oxygen atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The resulting product was NMC with a stoichiometry of LiNi0.8Mn0.1Co0.1O2. The product was then dry ground by mortar and pestle. The composition of the resulting final NMC product as determined by ICP analysis is listed in Tables 18a and 18b. The NMC composition is consistent with the desired NMC811 stoichiometry. Moreover, the undetected mass of the sample (also in Table 18a) is only 1.08%, which is much smaller than the undetected mass in the LMO′ powder.

[0256] Figure 41 shows an XRD pattern of the final single crystal NMC811 product of Example 8. The sample is pure NMC811 phase with the O3 structure, indicating full conversion of the feedstock mixture to NMC811. From the XRD pattern, values of the lattice constants, cation mixing degree, and Bragg R value were obtained by Rietveld refinement, and are listed in Table 19.

[0257] Figure 42 shows SEM images of the final NMC811 product of Example 8. The final NMC811 product is in the form of a powder with primary particle sizes in the range of 0.1-10 μm and secondary particle sizes of about 2-5 μm.

[0258] Figure 43 shows EDS compositional maps of the final NMC811 product of Example 8. These show that the final NMC811 product has a homogeneous distribution of transition metals to within 0.1 μm resolution.

[0259] The final NMC811 product was incorporated into coin-half cells for electrochemical analysis. Table 20 shows the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100 of the final NMC811 product of Example 8.

[0260] Figure 44 shows the voltage curve of the first cycle for the final NMC811 product of Example 8.

[0261] Figure 45 shows the cycling performance curve for the final NMC811 product of Example 8.

[0262] Figure 46 shows the polarization curve for the final NMC811 product of Example 8. Example 9

[0263] In Example 9, the LMO' of Example 6 was processed using a feedstock heating step by placing 2 g of the LMO' in an alumina crucible and heating it in a tube furnace from room temperature to 550 °C at a rate of 5 °C / min and holding it at 550 °C for 7 h, all under flowing carbon dioxide atmosphere. Under continuous flowing carbon dioxide (CO2) atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The material resulting from this heating of LMO' in CO2(g) is henceforth referred to LMO'(CO2). An XRD pattern of LMO'(CO2) is shown in Figure 47. It has XRD peaks corresponding to Mn3O4, as indicated by the black circles in the figure, showing that the heating of LMO' in CO2(g) caused the transformation of LMO' into Mn3O4. It is believed that the Li in this sample is in amorphous oxide or carbonate phases, which were not detected by XRD.

[0264] The LMO'(CO2) was then ground in the absence of external (added) solvents using an automatic mortar grinder (Retsch RMO) for 1h to reduce its average particle size from about 5-8 μm to 1 μm. Thereafter, 0.466 g of the ground LMO'(CO2), 1.642 g of a new Ni source (Ni metal powder, 0.5 μm, Vale), 0.271 g of a new Co source (Co3O4, 97%, -400 mesh, Freeport Cobalt), and 1.482 g of a new lithium source (Li2CO3, 99.7%, -400 mesh, Alfa Aesar) were ground in the absence of external solvents using an automatic mortar grinder for 3h. The resulting feedstock mixture had a Ni:Mn:Co molar ratio of 8:1:1 and a lithium content that was 20 atomic% in excess of the desired final LiNi0.8Mn0.1Co0.1O2 stoichiometry. The feedstock mixture was observed by EDS mapping to be a random distribution of feedstock mixture components within a 2 μm scale. The feedstock mixture was then placed in an alumina crucible and heated in a tube furnace from room temperature to 650 °C at a rate of 5 °C / min and then held at a temperature of 650 °C for 1 h. Then the temperature was increased to 880 °C at a rate of 5 °C / min and then held at a temperature of 880 °C for 12 h. The above heating process was done under flowing oxygen atmosphere. Under continuous flowing oxygen atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The resulting product was NMC with a stoichiometry of LiNi0.8Mn0.1Co0.1O2. The product was then dry ground by mortar and pestle. The composition of the resulting final NMC product as determined by ICP analysis is listed in Tables 18a and 18b. The NMC composition is consistent with the desired NMC811 stoichiometry. Moreover, the undetected mass of the sample (also in Table 18a) is near 0%, which is much smaller than the undetected mass in the LMO′ powder.

[0265] Figure 48 shows an XRD pattern of the final single crystal NMC811 product of Example 9. The sample is pure NMC811 phase with the O3 structure, indicating full conversion of the feedstock mixture to NMC811. From the XRD pattern, values of the lattice constants, cation mixing degree, and Bragg R value were obtained by Rietveld refinement, and are listed in Table 19.

[0266] Figure 49 shows SEM images of the final NMC811 product of Example 9. The final NMC811 product is in the form of a powder with primary particle sizes in the range of 0.1-10 μm and secondary particle sizes of about 2-5 μm.

[0267] Figure 50 shows EDS compositional maps of the final NMC811 product of Example 9. These show that the final NMC811 product has a homogeneous distribution of transition metals to within 0.1 μm resolution.

[0268] The final NMC811 product was incorporated into coin-half cells for electrochemical analysis. Table 20 shows the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100 of the final NMC811 product of Example 9.

[0269] Figure 51 shows the voltage curve of the first cycle for the final NMC811 product of Example 9.

[0270] Figure 52 shows the cycling performance curve for the final NMC811 product of Example 9.

[0271] Figure 53 shows the polarization curve for the final NMC811 product of Example 9. Example 10

[0272] In this example, LCO′ from Example 1, LMO′ from Example 2, and NMC811′ and NMC622′ from Example 3 were used. Specifically, 0.195 g of LCO′ from Example 1, 0.243 g of LMO′ from Example 2, 0.281 g of NMC811′ from Example 3, and 0.274 g of NMC622′ from Example 3 were mixed by hand by mortar and pestle and processed using a feedstock heating step. The feedstock heating step was done by placing the mixture in an alumina crucible and heating it in a tube furnace from room temperature to 700 °C at a rate of 5 °C / min and holding it at 700 °C for 7 h, all under flowing carbon dioxide atmosphere. Under continuous flowing carbon dioxide atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The material resulting from heating in CO2(g) is henceforth referred to as (NMC811'+NMC622'+LCO'+LMO')(CO2). An XRD pattern of (NMC811'+NMC622'+LCO'+LMO')(CO2) is shown in Figure 54, showing that (NMC811'+NMC622'+LCO'+LMO')(CO2) is comprised of NiO, Ni, MnO, CoO, and Li2CO3 phases. This shows that the original mixture of used cathode materials having layered and spinel structures was reduced to NiO, Ni, MnO, CoO and Li2CO3during the heating step in CO2. The (NMC811'+NMC622'+LCO'+LMO')(CO2) was then ground inthe absence of external solvents using an automatic mortar grinder (Retsch RMO) for 1h to reduce its average particle size from about 4-8 μm to 1 μm. Thereafter, the ground (NMC811'+NMC622'+LCO'+LMO')(CO2), 0.99 g of a new Ni source (Ni metal powder, 0.5 μm, Vale), and 0.853 g of a new lithium source (Li2CO3, 99.7%, -400 mesh, Alfa Aesar) were dry mixed and ground in the absence of solvents using an automatic mortar grinder (Retsch RMO) for 3 h. The resulting feedstock mixture components had an overall Ni:Mn:Co molar ratio of 8:1:1. These feedstock mixture components were observed by EDS mapping to be a random distribution of feedstock mixture components within a 2 μm scale, indicating homogeneous distribution. These feedstock mixture components were then placed in an alumina crucible and heated in a tube furnace from room temperature to 650 °C at a rate of 5 °C / min and then held at a temperature of 650 °C for 1 h. Then the temperature was increased to 880 °C at a rate of 5 °C / min and then held at a temperature of 880 °C for 12 h. The above heating process was under flowing oxygen atmosphere. Under flow oxygen atmosphere, the furnace was then allowed to naturally cool to below 100 °C. The product was then dry ground by mortar and pestle. The composition of the NMC product as determined by ICP analysis is listed in Tables 22a and 22b. The NMC composition is consistent with the desired NMC811 stoichiometry. Moreover, the undetected mass of the sample is 0.65%, which is much smaller than the undetected mass in the LMO′, LCO′ and NMC811′ powders. This shows that more than 99% of the undetected species in the LMO′, LCO′, and NMC811′ powders have been removed during the synthesis process. These impurities include binder, carbon black, etc.

[0273] Figure 55 shows an XRD pattern of the final NMC811 product of Example 10. The sample is pure NMC811 phase with the O3 structure, indicating full conversion of the feedstock mixture to NMC811. From the XRD pattern, values of the lattice constants, cation mixing degree, and Bragg R value were obtained by Rietveld refinement are listed in Table 21.

[0274] Table 21 shows lattice constants, cation mixing degree and Bragg R obtained by Rietveld refinement of NMC811 in Example 10. Example a c Cation Mixing Bragg R Å Å

[0275] Figure 56 shows SEM images of the final NMC811 product of Example 10. The final NMC811 product is in the form of a powder with primary particle sizes in the range of about 0.1-10 μm and secondary particle sizes of about 2-5 μm.

[0276] Figure 57 shows EDS compositional maps of the final NMC811 product of Example 10. These show that the final NMC811 product is a homogeneous distribution of transition metals to within 0.1 μm resolution.

[0277] Table 22 shows the discharge capacity of the first cycle, the initial coulombic efficiency (ICE), the voltage polarization at first cycle, and the discharge capacity at cycle 100. Example Discharge capacity Discharge capacity ICE Polarization at cycle 1 at cycle 100 (%) at cycle 1g g y final NMC811 product of Example 10.

[0279] Figure 59 shows the cycling performance curve for the final NMC811 product of Example 10.

[0280] Figure 60 shows the polarization curve for the final NMC811 product of Example 10.

[0281] Tables 22a and 22b show the ICP results of all components in the final product NMC811 of Example 10. Table 22a Sm lMain Elements Undetected MassTable 22b NMC811 (wt%)Al 0.07Alternatives:

[0282] Some methods herein may be described according to the following non- limiting alternatives:

[0283] Alternative 1. A method of synthesizing a lithium ion battery cathode material; the method comprising: providing feedstock mixture components that includes one or more used cathode materials recovered from used lithium-ion batteries comprising: LCO′, LMO′, NCA′ and / or one or more types of NMC′; combining the feedstock components into a feedstock mixture having the same transition metal and dopant atomic ratio as a desired stoichiometry in the synthesized lithium ion battery cathode material product; and heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C to produce the lithium ion battery cathode material product; wherein more than 10 wt% of the feedstock mixture is a used cathode material with a transition metal composition that differs from the composition of the synthesized lithium ion battery cathode material product.

[0284] Alternative 2. The method of alternative 1, wherein the lithium ion battery cathode material product has the formula Li1+p[(NinMnmCoc)1-aAa]1-pO2, where - 0.03 ≤ p ≤ 0.06; n + m + c = 1; n ≥ 0.30; m ≥ 0.05; c ≥ 0; A is a metal dopant; and 0 ≤ a ≤ 0.05.

[0285] Alternative 3. The method of alternative 2, wherein the dopant is 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, and mixtures thereof but excludes the metals Ni, Mn, and Co.

[0286] Alternative 4. The method of alternative 1, wherein the one or more used cathode materials is LCO′.

[0287] Alternative 5. The method of alternative 1, wherein the one or more used cathode materials is LMO′.

[0288] Alternative 6. The method of alternative 1, wherein the one or more used cathode materials is NMC′.

[0289] Alternative 7. The method of any one of alternatives 1 and 4, wherein the lithium ion battery cathode material product is NCA.

[0290] Alternative 8. The method of any one of alternatives 1, wherein the one or more used cathode materials is free of iron.

[0291] Alternative 9. The method of alternative any one of alternatives 1-8, wherein the feedstock mixture additionally comprises one or more new cathode metal sources.

[0292] Alternative 10. The method of any one of alternatives 1-9, wherein the feedstock mixture additionally comprises one or more new Ni, Co, Mg, Al, or Li metal source powders.

[0293] Alternative 11. The method of any one of alternatives 1 and 4-6, wherein the lithium ion battery cathode material product is NMC.

[0294] Alternative 12. The method of any one of alternatives 1, 4 and 7, wherein the one or more used cathode materials comprises or is NCA′.

[0295] Alternative 13. The method of any one of alternatives 1, 7, and 12 wherein the lithium ion battery cathode material product has the formula LiNidCoeAlfO2, known as NCA, where d + e + f = 1, d > 0.6, and 0.01 ≤ f ≤ 0.1.

[0296] Alternative 14. The method of any one of alternatives 1, 6-7, and 9-13, wherein lithium ion battery cathode material product has an O3 layered structure.

[0297] Alternative 15. The method of any one of alternatives 1-14, wherein the feedstock mixture includes waste materials comprising waste fines from cathode production, waste electrode slurry, waste cathode scraps that have never been incorporated into a battery cell, and cathode powders from reject cells that have never been cycled.

[0298] Alternative 16. A method for converting a used lithium-ion cathode material into a new lithium-ion cathode material for a battery cell, the method comprising: providing one or more used cathode materials recovered from one or more battery cells, wherein the one or more used cathode materials have a first transition metal stoichiometry; mixing the one or more used cathode materials with one or more new metal sources or used cathode materials in the absence of an added solvent to produce a feedstock mixture; and heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700°C to produce the new lithium cathode material having a second transition metal stoichiometry different than the first transition metal stoichiometry.

[0299] Alternative 17. The method of alternative 16, wherein the used cathode materials are less than 50 wt% in the feedstock mixture and the new metal sources are more than 50 wt% in the feedstock mixture or wherein the used cathode materials are at least 10 wt% of the feedstock mixture.

[0300] Alternative 18. The method of alternative 16, wherein the first transition metal stoichiometry is that of one type of NMC and the second transition metal stoichiometry is that of another type of NMC.

[0301] Alternative 19. The method of alternative 16, wherein the first transition metal stoichiometry is that of one type of LMO and the second transition metal stoichiometry is that of one type of NMC.

[0302] Alternative 20. The method of alternative 16, wherein the first transition metal stoichiometry is that of one type of LCO and the second transition metal stoichiometry is that of one type of NMC.

[0303] Alternative 21. The method of alternative 16, wherein the first transition metal stoichiometry is that of one type of LCA and the second transition metal stoichiometry is that of one type of NMC.

[0304] Alternative 22. The method of alternative 16, wherein the first transition metal stoichiometry comprises one or more types of LCO′, LMO′, NCA′ and / or one or more types of NMC′.

[0305] Alternative 23. The method of alternative 16, wherein the second stoichiometry transition metal comprises one or more types of LCO, LMO, NCA and / or one or more types of NMC.

[0306] Alternative 24. The method of any one of alternatives 16-23, wherein the mixing is a dry mixing.

[0307] Alternative 25. The method of any one of alternatives 16-23, wherein the ratio of used or waste components to new cathode materials is in the range of 10:90 to 40:60.

[0308] Alternative 26. The method of any one of alternatives 16-23, wherein no purification or separation steps are performed before or after the heating and the used cathode materials include at least one of electrolyte salts, separator components, anode active materials, electrolyte solvent, and binder.

[0309] Alternative 27. The method of any one of alternatives 16-23, wherein the used cathode materials do not include iron or copper.

[0310] Alternative 28. The method of any one of alternatives 1-27, wherein prior to the mixing or the combining the one or more used cathode materials are heated at a temperature greater than 300 °C in a CO2(g) atmosphere or in an argon / hydrogen gas mixture.

[0311] Alternative 29. The method of any one of alternatives 1-27, wherein after the mixing the mixture is heated at a temperature greater than 300 °C in a CO2(g) atmosphere or in an argon / hydrogen gas mixture.

[0312] Alternative 30. A new lithium-ion cathode material produced according to alternative 16, wherein the new lithium-ion cathode material is free of non-electrolyte solvent residues.

[0313] Alternative 31. The new lithium-ion cathode material produced according to alternative 29, wherein the new lithium-ion cathode material is a single crystal cathode powder.

[0314] Alternative 32. A method for converting a used lithium-ion cathode material into a new lithium-ion cathode material for a battery cell, the method comprising: providing one or more used cathode materials recovered from one or more battery cells, wherein the one or more used cathode materials have a first transition metal stoichiometry; heating the one or more used cathode materials in an initial atmosphere containing CO2(g) or Ar / H2 gas mixture at a temperature greater than 300 °C; mixing the one or more used cathode materials with one or more new metal sources or used cathode materials in the absence of an added solvent to produce a feedstock mixture; and heating the feedstock mixture in an atmosphere containing O2(g) at a temperature greater than about 700 °C to produce the new lithium cathode material having a second transition metal stoichiometry different than the first transition metal stoichiometry.

[0315] Alternative 33. The method of Alternative 32, wherein the heating in the initial atmosphere is performed prior to the mixing.

[0316] Alternative 34. The method of Alternative 32, wherein the heating in the initial atmosphere is performed after the mixing.

[0317] Alternative 35. The method of any one of Alternatives 33-34, wherein the initial atmosphere is a CO2(g) atmosphere.

[0318] Alternative 36. The method of any one of Alternatives 33-34, wherein the initial atmosphere is an Ar / H2gas mixture.

[0319] Alternative 37. The method of any one of Alternatives 33-36, wherein the initial atmosphere does not have elemental oxygen (O2).

[0320] Alternative 38. The method of any one of Alternatives 33-37, wherein the initial atmosphere only has trace amounts of gases that are not CO2(g) or Ar / H2.

[0321] Alternative 39. The method of any one of Alternatives 33-38, wherein the initial atmosphere consists of or consists essentially of CO2(g).

[0322] Alternative 40. The method of any one of Alternatives 33-38, wherein the initial atmosphere consists of or consists essentially of the Ar / H2 gas mixture.

[0323] Alternative 41. The method of any one of Alternatives 1-40, wherein the one or more used cathode materials are only subjected to heating and mixing steps prior to synthesizing the new lithium ion battery cathode material.

[0324] Alternative 41. The method of any one of Alternatives 1-41, wherein no solvent-based or mechanical separation techniques are performed on the one or more used cathode materials prior to synthesizing the new lithium ion battery cathode material.

[0325] Alternative 42. The method of Alternative 34, wherein the mixture is only comprised of used cathode materials.

[0326] Alternative 43. The method of Alternative 32 and 35-42, wherein the heating in the initial atmosphere is performed after the mixing and the mixture is solely comprised of used cathode materials.

[0327] Alternative 43. The method of Alternative 43, wherein the mixture is comprised of a plurality of used cathode materials.

[0328] Alternative 44. The method of Alternatives 32 or 33, wherein the mixture is comprised of a plurality of used cathode materials, each with a unique transition metal stoichiometry.

[0329] Alternative 45. The method of any one of Alternatives 1-44, wherein a feedstock heating step in an initial atmosphere is performed without adding an additional lithium source to the one or more used cathode materials.

[0330] Alternative 46. The method of any one of Alternatives 1-44, wherein heating prior to the mixing is performed without adding an additional lithium source to the one or more used cathode materials. Additional Notes

[0331] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

[0332] Reference throughout the specification to “one example”, “another example”, “an example”, and so forth, means that a particular element (e.g., feature, structure, and / or characteristic) described in connection with the example is included in at least one example described herein, and may or may not be present in other examples. In addition, it is to be understood that the described elements for any example may be combined in any suitable manner in the various examples unless the context clearly dictates otherwise.

[0333] It is to be understood that the ranges provided herein include the stated range and any value or sub-range within the stated range, as if such value or sub-range were explicitly recited. For example, a range from about 2 nm to about 20 nm should be interpreted to include not only the explicitly recited limits of from about 2 nm to about 20 nm, but also to include individual values, such as about 3.5 nm, about 8 nm, about 18.2 nm, etc., and sub-ranges, such as from about 5 nm to about 10 nm, etc. Furthermore, when “about” and / or “substantially” are / is utilized to describe a value, this is meant to encompass minor variations (up to + / - 10%) from the stated value (whether mol%, wt%, vol%, etc).

[0334] While several examples have been described in detail, it is to be understood that the disclosed examples may be modified. Therefore, the foregoing description is to be considered non-limiting.

[0335] While certain examples have been described, these examples have been presented by way of example only and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the systems and methods described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.

[0336] Features, materials, characteristics, or groups described in conjunction with a particular aspect, or example are to be understood to be applicable to any other aspect or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The protection is not restricted to the details of any foregoing examples. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0337] Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a sub- combination or variation of a sub-combination.

[0338] Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results, unless provided otherwise herein. Other operations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in someexamples, the actual steps taken in the processes illustrated and / or disclosed may differ from those shown in the figures. Depending on the example, certain of the steps described above may be removed or others may be added. Furthermore, the features and attributes of the specific examples disclosed above may be combined in different ways to form additional examples, all of which fall within the scope of the present disclosure.

[0339] For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular example. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0340] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain examples include, while other examples do not include, certain features, elements, and / or steps. Thus, such conditional language is not generally intended to imply that features, elements, and / or steps are in any way required for one or more examples.

[0341] Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain examples require the presence of at least one of X, at least one of Y, and at least one of Z.

[0342] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result.

[0343] The scope of the present disclosure is not intended to be limited by the specific disclosures of preferred examples in this section or elsewhere in this specification and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.

[0344] Although the foregoing invention has been described in terms of certain preferred embodiments, other embodiments will be apparent to those of ordinary skill in the art. Additionally, other combinations, omissions, substitutions, and modifications will be apparent to the skilled artisan, in view of the disclosure herein. Accordingly, the present invention is not intended to be limited by the recitation of the preferred embodiments but is instead to be defined by reference to the appended claims.

[0345] The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive manner and unless otherwise indicated refers to the ordinary meaning as would be understood by one of ordinary skill in the art in view of the specification. Furthermore, embodiments may comprise, consist of, consist essentially of, several novel features, no single one of which is solely responsible for its desirable attributes or is believed to be essential to practicing the embodiments herein described. As used herein, the section headings are for organizational purposes only and are not to be construed as limiting the described subject matter in any way. When definitions of terms in incorporated references appear to differ from the definitions provided in the present teachings, the definition provided in the present teachings shall control. It will be appreciated that there is an implied “about” prior to the temperatures, concentrations, times, etc. discussed in the present teachings, such that slight and insubstantial deviations are within the scope of the present teachings herein unless provided otherwise herein.

[0346] Although this disclosure is in the context of certain embodiments and examples, those of ordinary skill in the art will understand that the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses of the embodiments and obvious modifications and equivalents thereof. In addition, while several variations of the embodiments have been shown and described in detail, other modifications, which are within the scope of this disclosure, will be readily apparent to those of ordinary skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another in order to form varying modes or embodiments of the disclosure. Thus, it is intended that the scope of the present disclosure herein disclosed should not be limited by the particular disclosed embodiments described above.

Claims

WHAT IS CLAIMED IS:

1. A method of synthesizing a lithium nickel manganese cobalt oxide (NMC) particulate product having the formula Li1+p[(NinMnmCoc)1-aAa]1-pO2, where -0.03 ≤ p ≤ 0.06; n + m + c = 1; n ≥ 0.30; m ≥ 0.05; c ≥ 0; A is a metal dopant; and 0 ≤ a ≤ 0.05; the method comprising: a. providing feedstock mixture components that includes one or more used cathode materials recovered from used lithium-ion batteries comprising: LCO′, LMO′ and / or one or more types of NMC′; b. combining the feedstock components into a feedstock mixture having the same transition metal and dopant atomic ratio as a desired stoichiometry in the NMC particulate product to be synthesized; and c. heating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C to produce the NMC particulate product; wherein more than about 10 wt% of the feedstock mixture is a used cathode material with a transition metal composition that differs from the transition metal composition of the synthesized NMC particulate product.

2. The method according to claim 1, wherein a degree of lithium deficiency in the one or more used cathode materials is between 0% - 100%.

3. The method according to claim 1, wherein the feedstock mixture further comprises a new lithium source, such that the feedstock mixture contains an excess of lithium of up to 40 atomic% more than the stoichiometry of lithium in the synthesized NMC particulate product.

4. The method according to claim 1, wherein the feedstock mixture further comprises at least one of a new nickel source, a new cobalt source, a new manganese source and a dopant source.

5. The method according to claim 4, wherein the new nickel source comprises Ni, NiO or mixtures thereof, the new cobalt source comprises Co, CoO or mixtures thereof, the new manganese source comprises Mn, MnO, Mn3O4, MnO2 or mixtures thereof, and the dopant source comprises W, WO3, MgO, Bi, Bi2O3, V2O5, Na2O, NaOH, B2O3, Al2O3, NCA′, TiO2, ZnO, ZrO2, MoO3, MoO2 or mixtures thereof.

6. The method according to claim 1, that includes a grinding step prior to the combining in which the particle size of all or some of the feedstock mixture components is reduced.

7. The method according to claim 1, wherein the one or more used cathode materials comprise at least 1% by weight impurities comprised of separator components, electrolyte solvent, electrolyte salt, binder and / or carbon in the form of carbon black, carbon nanotubes or graphite.

8. The method according to claim 1, further comprising determining the chemical composition of the feedstock components prior to combining the feedstock components into the feedstock mixture.

9. The method according to claim 1, wherein the NMC particulate product is a single crystal cathode material.

10. The method according to claim 7, wherein at least 50% of the impurities are removed during the heating of the feedstock mixture.

11. The method according to claim 1, wherein the feedstock mixture is free of added solvents that were not recovered from the used lithium-ion batteries.

12. The method according to claim 1, wherein the method is an all-dry process substantially free of water or aqueous solvents.

13. The method according to claim 1, wherein the one or more used cathode materials are not subjected to any separation or purification processes before the combining and are heated at a temperature greater than 300 °C prior to the combining.

14. The method according to claim 1, wherein prior to the combining the one or more used cathode materials are heated at a temperature greater than 300 °C in a CO2(g) atmosphere or in an argon / hydrogen gas mixture.

15. An NMC cathode material produced according to the method of Claim 1, wherein the NMC cathode material is free of solvent residues.

16. The NMC cathode material according to Claim 15, wherein the NMC cathode material is comprised of single crystal particles.

17. A method for converting a used lithium-ion cathode material into a new lithium-ion cathode material for a battery cell, the method comprising: providing one or more used cathode materials recovered from one or more battery cells, wherein the one or more used cathode materials have a first transition metal stoichiometry; mixing the one or more used cathode materials with one or more new metal sources or an additional used cathode material in the absence of an added solvent to produce a feedstock mixture; andheating the feedstock mixture in an oxygen containing atmosphere at a temperature greater than about 700 °C to produce the new lithium- ion cathode material having a second transition metal stoichiometry different than the first transition metal stoichiometry.

18. The method of Claim 17, wherein the one or more used cathode materials or additional used cathode material have not been separated from impurities prior to the mixing, wherein the impurities include one or more of separator components, electrolyte solvent, electrolyte salt, binder and carbon.

19. The method of Claim 17, wherein at least 1 wt% of the used cathode materials are comprised of impurities selected from the group consisting of separator components, electrolyte solvent, electrolyte salt, binder and carbon.

20. The method of Claim 17, wherein the one or more new metal sources is at least one of a Ni source, Co source, Mn source or dopant element source.

21. The method of Claim 17, wherein the one or more new metal sources include a new nickel source, a new manganese source, a new cobalt source and an optional new dopant source.

22. The method of Claim 21, wherein the one or more new metal sources additionally include a new lithium source.

23. The method of Claim 17, wherein the one or more used cathode materials are mixed with the additional used cathode material, wherein the one or more used cathode materials have a different transition metal stoichiometry from the transition metal stoichiometry of the additional used cathode material.

24. The method of Claim 17, wherein the additional used cathode material has a third stoichiometry different from the first stoichiometry.

25. The method of Claim 17, wherein the one or more used cathode materials include LCO′, LMO′, and / or one or more stoichiometries of NMC′ and the new lithium cathode material is NMC.

26. The method of Claim 17, wherein the method is an all-dry method and the entire process is free of water.

27. The method of Claim 17, wherein the one or more used cathode materials comprise active and inactive cathode materials.

28. The method of Claim 17, wherein the feedstock mixture includes waste materials comprising waste fines from cathode production, waste electrode slurry, wastecathode scraps that have never been incorporated into a battery cell and cathode powders from reject cells that have never been cycled.

29. The method of Claim 18, wherein more than 90% of the impurities are removed during the heating of the feedstock mixture.

30. The method of Claim 17, wherein prior to the mixing the one or more used cathode materials are heated at a temperature greater than 300 °C.

31. The method of Claim 30, wherein the heating prior to the mixing is performed in an atmosphere of CO2(g) or in an argon / hydrogen gas mixture.

32. A new lithium-ion cathode material produced according to Claim 17, wherein the new lithium-ion cathode material is free of non-electrolyte solvent residues.

33. The new lithium-ion cathode material produced according to Claim 32, wherein the new lithium-ion cathode material has single crystal morphologies.

Images