[0001] This application claims the benefit of United States Provisional Patent

Application No. 63/374,569, entitled “METHOD AND APPARATUS FOR BATTERY CATHODE MATERIALS UPCYCLING,” filed September 5, 2022, which is hereby incorporated by reference herein in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] This invention was made with government support under Grant DE-SC0020868 awarded by the Department of Energy. The government has certain rights in the invention.

TECHNOLOGY FIELD

[0003] The present application generally relates to battery recycling, and more particularly to upcycling spent battery materials.

BACKGROUND

[0004] Lithium-ion batteries (LIBs) are widely used in many electrical devices, vehicles, etc. Spent LIBs may result in environmental problems and resource waste. End-of-life (EoL) LIBs are set to become significant secondary sources for materials used in producing new batteries. Reducing the recycling costs and enhancing the recycling rate can substantially decrease the life cycle cost of LIBs. This reduction can also prevent material shortages, mitigate the environmental impact of producing new materials, and offer low-cost active materials for manufacturing new LIBs. With the anticipated surge in cell production over the next decade, primary scrap from production emerges as a crucial source for global recycling initiatives. At present, the industry predominantly relies on high-temperature pyrometallurgical or hydrometallurgical methods for recycling LIBs. These methods are often followed by acidic leaching or alkaline treatment processes to recover valuable elements like Li, Ni, and Co. However, the reliance on high temperatures and intensive chemical processes result in significant energy consumption, new chemical waste production, and high operating costs. For LIB recycling to be profitable without imposing disposal fees on consumers and to stimulate industry expansion, innovative recycling techniques are essential. Direct recycling, which involves the recovery and reuse of battery components without altering their chemical structure, offers a route to provide battery manufacturers with more affordable re-constituted materials. This approach can potentially decrease the cost of electric vehicle (EV) batteries, thus enhancing the attractiveness of recycling them. [0005] Direct recycling of LIBs is gaining traction as a viable method. It enables the regeneration of cathode and anode materials without disrupting their compounds, and substantially curtails energy and chemical use. However, the challenge lies in the age difference between recovered and contemporary materials; regenerated electrode materials, being typically 5 to 10 years older, might not align with the evolving market demands, given the advancements in electrode material properties and the advent of novel chemistries.

[0006] The development of an effective upcy cling process, which restores materials in a high-value form for resale to manufacturers, is pivotal for promoting LIB recycling. An upcy cling infrastructure driven by profitability can align with market objectives, which include reducing battery costs and enhancing the incorporation of recycled battery materials.

[0007] During prolonged cycling, many particles in cathode materials, such as

Li NixCoy MnzCb (NCM) and LiNi _x Co _y Al _z O2 (NCA) (where x + y + z = 1), frequently disintegrate into primary nanoparticles. The loss of this secondary structure amplifies the exposure of new surfaces to the electrolyte, leading to material degradation and subsequent decline in electrochemical performance. This deterioration complicates the full recovery of electrochemical performance in standard hydrothermal or high-temperature relithiation processes, which often can't counteract the disintegration of these nanoparticles.

SUMMARY

[0008] The following is a simplified summary of the disclosure in order to provide a basic understanding of some aspects of the disclosure. This summary is not an extensive overview of the disclosure. It is intended to neither identify key or critical elements of the disclosure, nor delineate any scope of the particular implementations of the disclosure or any scope of the claims. Its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0009] According to one or more aspects of the present disclosure, methods for upcycling spent batteries are provided. The methods include: separating cathode materials of the spent batteries into a plurality of groups of particles, wherein a first group of the plurality of groups of particles includes first particles of first sizes, and wherein a second group of the plurality of groups of particles includes second particles of second sizes; generating a first precursor solution using the first particles; generating a second precursor solution using the second particles; generating first cathode materials using the first precursor solution; and generating second cathode materials using the second precursor solution. [0010] In some embodiments, the first particles are microparticles, and the second particles are nanoparticles.

[0011] In some embodiments, the first precursor solution includes at least one of a suspension containing the first group of particles or a solution containing the first group of particles.

[0012] In some embodiments, the first precursor solution further includes at least one of LiOH, LiNCh, LiAc, Ni(NO ₃ ) ₂ , Mn(NO ₃ ) ₂ , Co(NO ₃ ) ₂ , C ₂ H ₂ O ₄ Ni, Ni(Ac) ₂ , C ₂ H ₂ O ₄ Mn, Mn(Ac) ₂ , Ci ₂ HwMn ₃ 0i ₄ , C ₂ H ₂ O ₄ Co, Co(Ac) ₂ , A1(NO ₃ ) ₃ .

[0013] In some embodiments, the first precursor solution further includes a lithium precursor.

[0014] In some embodiments, the first precursor solution includes at least one dopant precursor.

[0015] In some embodiments, generating the first cathode materials using the first precursor solution includes: calcinating the first precursor solution to produce first calcinated particles; and performing surface engineering on the first calcinated particles.

[0016] In some embodiments, generating the second cathode materials using the second precursor solution includes: forming a plurality of microparticles using the second precursor solution; and calcinating the plurality of microparticles to produce second calcinated particles. [0017] In some embodiments, forming the plurality of microparticles using the second precursor solution includes producing micronized droplets utilizing at least one of a spray granulation process or a spray drying process.

[0018] In some embodiments, generating the second cathode materials using the second precursor solution further includes performing surface engineering on the second calcinated particles.

[0019] In some embodiments, the second precursor solution includes at least one of a suspension containing the second group of particles or a solution containing the second group of particles.

[0020] In some embodiments, the second precursor solution includes at least one of LiOH, LiNO ₃ , LiAc, Ni(NO ₃ ) ₂ , Mn(NO ₃ ) ₂ , Co(NO ₃ ) ₂ , C ₂ H ₂ O ₄ Ni, Ni(Ac) ₂ , C ₂ H ₂ O ₄ Mn, Mn(Ac) ₂ , Ci ₂ HwMn ₃ 0i ₄ , C ₂ H ₂ O ₄ Co, Co(Ac) ₂ , or A1(NO ₃ ) ₃ .

[0021] In some embodiments, the second precursor solution includes a Li precursor, wherein the Li precursor includes at least one of LiOH, LiNO ₃ , LiAc.

[0022] In some embodiments, the second precursor solution includes a Mn precursor, wherein the Mn precursor includes at least one of Mn(Ac) ₂ , Mn(NO ₃ ) ₂ , C ₂ H ₂ O ₄ Mn, Ci ₂ HwMn ₃ 0i ₄ , or Mn(NO ₂ ) ₂ . [0023] In some embodiments, the second precursor solution includes a Co precursor, and wherein the Co precursor includes at least one of Co(Ac)2, Co(NO3)2, C2H2O4CO, Co(NO2)2.

[0024] In some embodiments, the second precursor solution includes an Al precursor, wherein the Al precursor includes at least one of A1[OCH(CH3)2]3, A1(N(CH3)2)3, A1[OCH(CH3)C ₂ H ₅ ]3, (CH ₃ ) ₃ A1, A1(NO ₃ )3.

[0025] In some embodiments, the second precursor solution includes one or more dopant precursors, wherein the dopant precursors include at least one of Al, Ti, Mg, Ca, Nb, Zr, W, Te, Mo, or F.

[0026] According to one or more aspects of the present disclosure, systems for upcycling spent batteries are provided. The systems may include a particle separator configured to separate cathode materials of spent batteries into a plurality of groups of particles, wherein a first group of the plurality of groups of particles includes first particles of first sizes, and wherein a second group of the plurality of groups of particles includes second particles of second sizes; a precursor generator configured to: generate a first precursor solution using the first particles; and generate a second precursor solution using the second particles; and a battery upgrading component configured to: generate first cathode materials using the first precursor solution; and generate second cathode materials using the second precursor solution.

[0027] In some embodiments, the first particles are microparticles. In some embodiments, the second particles are nanoparticles.

[0028] In some embodiments, the battery upgrading component further includes a calcination component configured to calcinate the first precursor solution to produce first calcinated particles and a surface engineering component configured to perform surface engineering on the first calcinated particles.

[0029] In some embodiments, the battery upgrading component further includes a microparticle reformation component configured to form a plurality of microparticles using the second precursor solution.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The disclosure will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the disclosure. The drawings, however, should not be taken to limit the disclosure to the specific embodiments, but are for explanation and understanding.

[0031] FIG. l is a schematic diagram illustrating an example system for upcycling spent batteries. [0032] FIG. 2 is a block diagram illustrating example processing processes for generating cathode materials in accordance with some embodiments of the present disclosure.

[0033] FIGS. 3 A and 3B are diagrams illustrating example processes for upcycling cathode materials in accordance with some embodiments of the present disclosure.

[0034] FIGS. 4 and 5 are schematic diagrams illustrating example microparticle generation reactors in accordance with some embodiments of the present disclosure.

[0035] FIG. 6 illustrates an example calcination system in accordance with some embodiments of the present disclosure.

[0036] FIG. 7 illustrates an example surface engineering reactor in accordance with some embodiments of the present disclosure.

[0037] FIGS. 8A, 8B, and 8C are flowcharts illustrating example processes for upcycling spent batteries in accordance with some embodiments of the present disclosure.

[0038] FIG. 9A is an SEM image of aged NCA cathode materials.

[0039] FIG. 9B is an SEM image of separated damaged nanoparticles.

[0040] FIG. 9C is an SEM image of morphology-upgraded microparticles of upcycled

NCA cathode materials.

[0041] FIG. 9D illustrates the cycling performance of the upcycled NCA cathode materials in FIG. 9C and commercial NCA cathode materials.

[0042] FIG. 10A illustrates the XRD pattern comparison between recycled polycrystalline NCM111 and upcycled single crystal NCM622 cathode materials.

[0043] FIG. 10B is an SEM image of upcycled single crystal NCM622 cathode mateirals from spent spent poly crystalline NCM111 cathode materials.

[0044] FIG. 10C shows the first cycle charge-discharge curve of commercial polycrystalline NCM622 and upcycled single crystal NCM622 cathode materials at 0.1 C.

[0045] FIG. 10D shows the comparison of cycling performance between upcycled single crystal NCM622 and commercial polycrystalline NCM622 cathode materials at 1C.

[0046] FIG. 11 A is an SEM image of spent LFP nanoparticles.

[0047] FIG. 1 IB is an SEM image of morphology-upgraded LFP cathode materials.

[0048] FIG. 11C illustrates the particle size distribution of the upgraded LFP cathode materials.

[0049] FIG. 1 ID showcases a comparison of cycling performance between spent LFP nanoparticles and the upgraded LFP microparticle cathode materials.

[0050] FIG. 12A is an SEM image of the morphology and chemistry -upgraded LMFP microparticle cathode materials. [0051] FIG. 12B represents the particle size distribution of the upgraded LMFP cathode materials.

[0052] FIG. 12C shows the XRD of upcycled LFP and LMFP microparticle cathode materials.

[0053] FIG. 12D depicts the second cycle charge-discharge curves of the upcycled LFP and LMFP cathode materials.

DETAILED DESCRIPTION

[0054] The present disclosure provides mechanisms (e.g., systems, apparatuses, methods, etc.) for upcycling spent batteries. As referred to herein, a battery may be any electric storage device. In some embodiments, the battery may be a lithium-ion battery (LIB). Spent batteries may include used and/or aged LIBs, battery modules, battery packs, etc. As used herein, "lithium-ion battery cathode material" refers to the material that constitutes the cathode of LIBs, including, but not limited to, lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium nickel cobalt manganese aluminum oxide, lithium manganese oxide, lithium iron phosphate, and lithium manganese iron phosphate.

[0055] Recycling LIBs may involve discharging spent LIBs and separating spent graphite using physical methods such as dismantling, crushing, screening, and other mechanical processes. The separated raw graphite anode materials may be processed to produce recycled anode materials (e.g., by direct regeneration of graphite) and/or upcycled anode materials (e.g., by upgrading the graphite anode materials to graphite-based materials with additional functions desirable for energy and environmental applications). However, the raw cathode materials obtained via the separation of the raw cathode materials from other components of the spent batteries may not be able to meet the standard of the battery industry due to the impurities and structural defects.

[0056] According to one or more aspects of the present disclosure, a system for battery upcycling is provided. The system may process spent batteries and may produce regenerated and/or upgraded cathode materials that may be used in electrodes in new batteries. For example, the system may process raw cathode materials of spent batteries (e.g., used and/or damaged LIB cathode materials) and classify the cathode particles in the raw cathode materials by size and/or morphology. In particular, the system may separate cathode particles with desired sizes, morphology, and crystallinity (also referred to as the “intact cathode particles”) from cathode particles lacking the desired sizes, morphology, and/or crystallinity (also referred to as the “damaged cathode particles”). In some embodiments, the intact cathode particles may include microparticles (e.g., particles of a dimension between 1 pm and 300 pm). The damaged cathode particles may include nanoparticles (e.g., particles of a dimension between 1 nm and 1000 nm). [0057] The system may generate upcycled cathode materials by processing the separated intact microparticles and the damaged nanoparticles. For example, the intact cathode particles may undergo regeneration and then a surface coating process to boost their stability. The damaged nanoparticles may be processed for morphology reconstruction and enhancement. The damaged and disintegrated particles to large particles (e.g., particles with a dimension of 1-100 microns) in a morphological recovering process that involves the formation of nanoparticle suspension or solution with modified chemistry composition and/or additional dopant(s) followed by quick gas-phase processing to form new particles with upgraded chemistry at low temperatures. In addition, the nano-precursors may be used as seeds for the synthesis of larger single-crystal particles.

[0058] The recycled cathode materials produced utilizing the mechanisms described herein may present the desired morphology, composition, dopant(s), and crystallinity The capacity of the upcycled cathode materials may be comparable to the capacity of the virgin cathode materials that are suitable for fabricating electrodes of new batteries (e.g., LIBs). The recycled cathode materials may include, for example, morphology-upgraded lithium-ion battery cathode particles, chemistry -upgraded LIB cathode particles, desired dopant(s), crystal structure upgraded LIB cathode particles, etc.

[0059] By swiftly separating particles and efficiently repairing damaged cathode particles, an impressive cathode yield (between 95% and 98%) may be realized. This is achieved with substantially less energy than the traditional, energy-consuming cathode re-synthesis from dissolved salt precursors. Such efficiencies may significantly boost the adoption rates of recycling and regeneration processes for LIBs. Additionally, these regenerated materials may be increasingly utilized in EVs, stationary power storage solutions, consumer electronics, etc. [0060] As used herein, "desired morphology" may refer to a predetermined morphological character of a particle. In some cases, the desired morphology is a desired shape and/or a desired size. In some cases, the desired morphology is substantially spherical.

[0061] As used herein, "desired crystallinity" or "desired crystalline structure" may refer to a predetermined crystal structure of a particle, which can conventionally be measured by x-ray diffractometry (XRD), or another method that is capable of providing similar information. In some cases, the desired crystallinity described herein is a layered structure with hexagonal symmetry that belongs to the space group R-3m (e.g., for NCM, NCA, and NCMA chemistries). In some embodiments, the desired crystallinity is an ilmenite-derived structure and belongs to the orthorhombic Pnma space group (e.g., for LFP and LMFP chemistry). As used herein, "morphology -upgraded lithium-ion battery cathode particle" may refer to lithium-ion battery cathode particles of which the morphology or/and particle size (e.g., nanoparticles) are adjusted. For example, used nanoparticles of NCA and LFP lithium-ion battery cathode particles can be upgraded by morphology reformation to microparticle spherical lithium-ion battery cathode particles.

[0062] As used herein, "chemistry upgraded lithium-ion battery cathode particle" may refer to lithium-ion battery cathode particles of which the stoichiometry of lithium and other elements are adjusted. For example, the stoichiometry of NCM523 lithium-ion battery cathode particles can be adjusted by adding more Li, Ni, and Co precursors so that they are upgraded to NCM81 1 lithium-ion battery cathode particles. The stoichiometry of LFP lithium-ion battery cathode particles can be adjusted by adding more Li, Mn, and P precursors so that they are upgraded to LMFP lithium-ion battery cathode particles.

[0063] As used herein, "crystal structure upgraded lithium-ion battery cathode particle" may refer to lithium-ion battery cathode particles of which the crystal structures are adjusted. For example, the poly crystalline NCM111 lithium-ion battery cathode particles can be adjusted by applying a second calcination process so that they are upgraded to NCM111 single-crystal lithium-ion battery cathode particles.

[0064] As used herein, "NCM" refers to lithium nickel cobalt manganese oxide. "NCA" refers to lithium nickel cobalt aluminum oxide. "NCMA" refers to lithium nickel cobalt manganese aluminum oxide. "LFP" refers to lithium iron phosphate. "LMFP" refers to lithium manganese iron phosphate.

[0065] FIG. 1 is a schematic diagram illustrating an example system 100 for upcy cling spent batteries. The spent batteries may include, for example, used and/or damaged LIBs.

[0066] As shown, system 100 may include a preprocessing component 110, a particle separator 120, a precursor generator 130, a microparticle reformation component 140, a calcination component 150, a surface engineering component 160, and/or any other suitable component for upcycling spent batteries according to the techniques described herein. Microparticle reformation component 140, calcination component 150, and surface engineering component 160 may be collectively referred to as a battery upgrading component 170. System 100 may include more or fewer modules without loss of generality. For example, two of the components may be combined into a single component, or one of the components may be divided into two or more components.

[0067] Preprocessing component 110 may process raw cathode materials of spent batteries using aqueous methods and produce preprocessed raw cathode materials 115. The raw cathode materials may be collected from the spent batteries, for example, by discharging the spent batteries and separating the raw cathode materials utilizing mechanical processes (e.g., dismantling, crushing, screening, etc.). The spent batteries may present the same chemistry type (e.g., including the same cathode materials) in some embodiments. The raw cathode materials may include, for example, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium nickel cobalt manganese aluminum oxide, lithium iron phosphate, lithium iron manganese phosphate, etc.

[0068] In some embodiments, preprocessing component 110 may purify the raw cathode materials by flowing a fluidized gas-solid stream of a particle mixture and may expose the particle mixture flowing through the plasma region to a non-equilibrium plasma. The plasma may have a predetermined power density for a predetermined exposure time and a predetermined solid-to-gas volume ratio to remove impurities.

[0069] Particle separator 120 may separate the preprocessed cathode materials 115 (e.g., purified cathode materials) into a plurality of groups of particles of varying sizes and/or morphology). Each of the groups may have particles of certain sizes and/or size distributions. For example, the preprocessed cathode materials 115 may be divided into a first group of particles 125a and a second group of particles 125b. The first group of particles 125a may have a desired morphology and/or desired particle sizes. The second group of particles 125b lacks the desired morphology or sizes of the first group. More particularly, for example, the first particles 125a may have a desired shape and/or size and may include intact spherical microparticles between about 1 and about 100 pm. The second particles 125b lack such morphology or size and may include nanoparticles between about 1 nm and about 1000 nm.

[0070] The separation of the first group and the second group of particles may be achieved in a gas-phase centrifuging process by controlling gas pressure and aerodynamics of gas flow. In some embodiments, particle separator 120 may use gas-phase centrifugal separation forces in a vortex motion to separate the preprocessed cathode materials 115 into the groups of particles. In some embodiments, particle separator 120 may include an axial cyclone separator coupled with swirling gas under a non-equilibrium and low-temperature plasma discharge. The axial cyclone separator may utilize rapid particle separation in a gas phase that directly and selectively selects intact cathode particles. The separation of the intact cathode particles and the damaged cathode particles may reduce steps and costs for recycling and upcycling cathode materials.

[0071] Precursor generator 130 may generate one or more precursor solutions using the first particles 125a and/or the second particles 125b. In some embodiments, the precursor solutions may include the group of particles 125a and/or the group of particles 125b, a solvent, a binder, etc. to form suspensions and/or solutions with one or more chemistry-adjusting additives, and one or more dopant precursors. The incorporation of small amounts (0.01-5%) of dopants occupying transition metal (TM) or Li or oxygen sites in the cathode structure may improve the structural and electrochemical properties of pristine cathode materials.

[0072] The chemistry-adjusting additives may include chemicals that contain Ni, Mn, Co, P, or Li and are used to contact the particles of used lithium-ion battery cathode materials to change the stoichiometry of each element in lithium-ion battery cathode materials (e.g., NCM, NCA, NCMA, LFP, LMFP). Examples of the chemistry-adjusting additives may include LiOH, LiNO ₃ , LiAc, Ni(NO ₃ ) ₂ , Mn(NO ₃ ) ₂ , Co(NO ₃ ) ₂ , C ₂ H ₂ O ₄ Ni, Ni(Ac) ₂ , C ₂ H ₂ O ₄ Mn, Mn(Ac) ₂ , Ci ₂ HwMn ₃ 0i ₄ , C ₂ H ₂ O ₄ Co, Co(Ac) ₂ , A1(NO ₃ ) ₃ , A1[OCH(CH ₃ ) ₂ ] ₃ , A1(N(CH ₃ ) ₂ ) ₃ , A1[OCH(CH ₃ )C ₂ H ₅ ] ₃ , (CH ₃ ) ₃ A1, etc.

[0073] The doping additives may include chemicals that contain Al, Ti, Mg, Ca, Nb, Zr, W, Te, Mo, F, etc. in place of Ni, Co, Mn, or oxygen (O). Doping strategies may play a crucial role in enhancing the structural and electrochemical properties of pristine cathode materials (e.g., NCM), where dopants occupy transition metal (TM), Li or oxygen sites in the layered cathode structure with a space group of R-3m. The incorporation of small amounts of one or more doping elements is effective in alleviating the volume change of layered cathode during phase transitions under high voltage conditions. On the other hand, the addition of one or more doping elements in the Li sites acts as a pillar, resulting in improved rate performance and structural stability during cycling. In addition, the addition of one or more doping elements in the Li sites may increase the energy density of cathode materials through oxygen oxidation and/or reduction. The solvent may include, for example, water, ethanol, methanol, isopropanol, ethylene glycol, etc. The organic binder may include, for example, polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), etc.

[0074] As an example, precursor generator 130 may generate a first precursor solution 135a using the first particles 125a. The first precursor solution 135a may further include a solvent, a binder, one or more chemistry-adjusting additives, one or more dopant precursors, etc. As another example, precursor generator 130 may generate one or more second precursor solutions 135b using the second particles 125b. Each of the second precursor solutions 135b may further include a solvent, a binder, one or more chemistry-adjusting additives, one or more dopant precursors, etc. The solvent may include, for example, water, ethanol, methanol, isopropanol, ethylene glycol, etc. The organic binder may include, for example, PEG, PVA, PVB, etc. The chemistry-adjusting additives may include a lithium (Li) precursor, a manganese (Mn) precursor, a nickel (Ni) precursor, a carbon (Co) precursor, an aluminum (Al) precursor, one or more dopant precursors, etc. The Li precursor may include, for example, LiOH, LiNO ₃ , LiAc, etc. Examples of the Ni precursor may include Ni(Ac) ₂ , Ni(NO ₃ ) ₂ , C ₂ H ₂ O ₄ Ni, NiBr ₂ , etc. Examples of the Mn precursor may include Mn(Ac) ₂ , Mn(NO ₃ ) ₂ , C ₂ H ₂ O ₄ Mn, Ci ₂ HioMn ₃ Oi ₄ , Mn(NO2)2, etc. Examples of the Co precursor may include Co(Ac)2, Co(NO3)2, C2H2O4CO, CO(NO2)2, etc. Examples of the Al precursor may include A1[OCH(CH3)2]3, Al(N(C h)2)3, A1[OCH(CH3)C2H5]3, (CH ₃ ) ₃ A1, A1(NO ₃ ) ₃ , , etc. The dopant precursors may include chemicals that contain Al, Ti, Mg, Ca, Nb, Zr, W, Te, Mo, or F in place of Ni, Co, Mn, or oxygen (O), etc. In some embodiments, the first precursor solution 135a may include a precursor solutions 210 as described in connection with FIG. 2. In some embodiments, the second precursor solutions 135b may include one more precursor solutions 220, 230, 240, and 250 as described in connection with FIG. 2.

[0075] Microparticle reformation component 140 may generate microparticles 145 using the second precursor solutions 135b. The microparticles may have a suitable size between 1 pm and 100 pm. For example, microparticle reformation component 140 may perform precursor powder synthesis via a droplet generation process. In some embodiments, the droplet generation process may involve producing micronized droplets utilizing a spray granulation process and/or a spray drying process. In some embodiments, the spray drying process and/or spray granulation process may involve droplet generation and drying a suspension or solution comprising a solution of the Li precursor having the particles suspended therein.

[0076] In some embodiments, the micronized droplets may be produced utilizing a centrifugal droplet generation process. The centrifugal droplet generation process may involve producing droplets using artificial gravitational forces.

[0077] In some embodiments, the spray drying or spray granulation may be tuned to produce agglomerates having a suitable size between 1 pm and 100 pm. For example, the spray drying or spray granulation may be tuned to give liquid droplets of a given size, which will subsequently dry to agglomerates of a desired size. In some embodiments, the droplet generator may be and/or include a centrifugal atomizer or gas atomizer to produce droplets with desired sizes (e.g., by adjusting the nozzle design, liquid selection, air flow, and reactor design, etc.).

[0078] In some embodiments, the spray drying reactor or the spray granulation reactor may use a drying gas to evaporate the liquid between 50 °C and 400 °C. The drying gas may be and/or include, for example, air, O2, N2, Ar, etc. In some embodiments, the dried microparticles have the desired morphology and may be spherical or substantially spherical.

[0079] In some embodiments, microparticle reformation component 140 may include a microparticle generation reactor 400 as described in connection with FIG. 4 and/or a microparticle generation reactor 500 as described in connection with FIG. 5.

[0080] Calcination component 150 may calcinate the first particles 125a to produce the first calcinated particles 155a and the microparticles 145 in situ. The calcination of the first particles 125a may enable relithiation of the first particles 125a and may produce first calcinated particles 155a. The calcination of the microparticles 145 may achieve relithiation, metal restoration, doping, crystallization, etc. of the microparticles 145 and may produce second calcinated particles 155b. For example, calcination component 150 may calcinate the first particles 125a and/or the microparticles 145 by boiling bed pre-calcination and warm plasma calcination. In a boiling bed pre-calcination process, a first elevated temperature causes a decomposition of the precursor compounds in the microparticles into oxides, which forms strong binding to bind all the small nanoparticles inside the particle together and prevent agglomeration due to incomplete decomposition of precursors. In the plasma calcination process, a second elevated temperature from internal plasma discharge is applied to pre-calcinated particles to form calcinated particles with desired crystallinity.

[0081] In some embodiments, calcination component 150 may apply the first elevated temperature to the first group of particles 125a for pre-calcination. In some embodiments, calcination component 150 may apply plasma at the second elevated temperature for additional calcination.

[0082] In some embodiments, the first elevated temperature and residence time of the particles in the boiling bed chamber provide control of the porosity and morphology of the particle. The second elevated temperature and the temperature profile along the particle flow path in this inline plasma calcination zone may be controlled by various parameters to achieve desired cathode materials.

[0083] In some embodiments, the first elevated temperature in the boiling bed is at a temperature between 200 °C and 700 °C. In some embodiments, the second elevated temperature in a plasma reactor is at a temperature between 600 °C and 2000 °C.

[0084] In some embodiments, calcination component 150 may perform an additional calcination process to upgrade the calcinated particles from polycrystalline to single crystal phase. In some embodiments, the additional calcination process may be performed in a chamber with or without plasma.

[0085] In some embodiments, calcination component 150 may include a calcination system 600 as described in connection with FIG. 6.

[0086] Surface engineering component 160 may perform surface engineering on the first calcinated particles 155a and the second calcinated particles 155b for relithiation, restoration, crystallization, carbon coating, and/or reformation of the calcinated particles. Surface engineering component 160 may produce the first cathode materials 165a by processing first calcinated particles 155a and may produce second cathode materials 165b by processing the second calcinated particles 155b. The first cathode materials 165a and second cathode materials 165b may be battery-grade cathode materials that may be used to fabricate cathode electrodes of new batteries.

[0087] In some embodiments, surface engineering component 160 may perform surface engineering processes utilizing a fluidized bed spray coating process. The coating process may adapt existing batch-by-batch state-of-the-art methods for battery recycling to facilitate continuous flow operation. When a solution or a suspension is used for coating, the liquid may act to transport the solids of a coating agent (also referred to as a precursor) to the particle surface. The fluidized bed spray coating may involve depositing a precursor on the first calcinated particles 155a and/or second calcinated particles 155b, followed by calcination in a second boiling bed. The coating precursor may include a mixture of one or more coating agents, solvents, binders, etc. The coating agent may include, for example, carbon, LiF, AI2O3, TiCh, ZrCh, LisPC , LiNbCh, and the like. Examples of the solvents may include water, ethanol, methanol, isopropanol, ethylene glycol, etc. In some embodiments, the binder may include, for example, PEG, PVA, PVB, etc. Surface engineering component 160 may include a surface engineering reactor 700 as described in connection with FIG. 7 in some embodiments.

[0088] FIG. 2 is a block diagram 200 illustrating example processing processes for generating cathode materials in accordance with some embodiments of the present disclosure.

[0089] In some embodiments, a precursor solution 210 may be processed by the in-line calcination component 150 and the surface engineering component 160 of FIG. 1 for surface coating. The precursor solution 210 may include the first particles 125a, a solvent, a binder, one or more lithium precursors, one or more dopant precursors, etc. The processing of the precursor solution 210 may produce cathode materials 210a.

[0090] In some embodiments, a precursor solution 220 may be processed by the microparticle reformation component 140, the in-line calcination component 150, and the surface engineering component 160 of FIG. 1 for morphology reformation. The precursor solution 220 may include the second particles, a solvent, a binder, one or more lithium precursors, one or more chemistry-adjusting additives, one or more dopant precursors, etc. The processing of the precursor solution 220 may produce cathode materials 220a.

[0091] In some embodiments, a precursor solution 230 may be processed by the microparticle reformation component 140, the calcination component 150, and the surface engineering component for chemistry upgrading. The precursor solution 230 may include the second particles 125b, a solvent, a binder, one or more lithium precursors, one or more chemistry-adjusting additives, one or more dopant precursors, etc. The processing of the precursor solution 230 may produce cathode materials 230a. [0092] In some embodiments, a precursor solution 240 may be processed by the microparticle reformation component 140 and the in-line calcination component 150 for crystal structure upgrading. For example, the microparticle reformation component 140 may generate microparticles using the precursor solution 240. The microparticles may then be calcinated by the calcination component 150 of FIG. 1. An additional calcination process may be carried out on the calcinated microparticles to produce cathode materials 240a. The precursor solution 240 may include second particles 125b, a solvent, a binder, one or more lithium precursors, etc.

Precursor solution 240 may or may not include a chemistry-adjusting additive. Precursor solution 240 may or may not include a dopant precursor.

[0001] In some embodiments, a precursor solution 250 may be processed by microparticle reformation component 140, calcination component 150, and surface engineering component 160 to produce cathode materials 250a. The precursor solution 250 may include second particles 125b, a metal leachate, a solvent, a binder, a lithium precursor with a chemistry-adjusting additive, etc. The precursor solution 250 may include one or more Ni precursors, Mn precursors, Co precursors, Li precursors, dopant precursors, etc.

[0002] FIGS. 3A and 3B are diagrams illustrating example particles of cathode materials in accordance with some embodiments of the present disclosure.

[0003] As shown in FIG. 3A, raw cathode materials 105 may be purified (e.g., by preprocessing component 110 of FIG. 1) and separated into first particles 125a and second particles 125b (e.g., by particle separator 120 of FIG. 1). First calcinated particles 155a may be generated by relithiation and calcination of first particles 125a (e.g., by precursor generator 130 and calcination component 150 of FIG. 1). First cathode materials 165a may be generated by performing surface engineering (e.g., surface coating) on first calcinated particles 155a (e.g., by surface engineering component 160 of FIG. 1). First particles 125a may be regenerated in later relithiation steps.

[0004] The sizes of second particles 125b normally in the range of 50-1000 nanometers. As will be described in greater detail below, second particles 125b may will be restored to large particles (5-15 microns) in a morphological recovering process that only involves the formation of nanoparticle suspension in water and then a quick gas phase processing at low temperatures from 40 to 400 °C.

[0005] Combining fast particle separation and quickly restoring damaged particles, high overall cathode yield (95%-98%) can be achieved at much lower energy consumption compared to the energy-intensive cathode re-synthesis process from dissolved salt precursors. This strongly accelerates the market penetration of recycling and regenerating LIBs and using regenerated materials for EVs and stationary power storage. [0006] Referring to FIG. 3B, microparticles 345a may be generated by adding one or more Li precursors, C precursors, dopant precursors to second particles 125b and upgrading the morphology of second particles 125b (e.g., using precursor generator 130 and microparticle reformation component 140 of FIG. 1). Calcinated particles 355a may be generated by calcinating microparticles 345a using calcination component 150 of FIG. 1. The calcination of microparticles 345a may achieve relithiation, element doping, and carbon coating of microparticles 345a. Upcycled cathode materials 365a may be generated by performing surface engineering (e.g., surface coating) on calcinated particles 355a (e.g., by surface engineering component 160 of FIG. 1).

[0007] Microparticles 345b may be generated by adding one or more Li precursors and one or more dopant precursors, M precursors, P precursors, C precursors, etc. to second particles 125b and upgrading the morphology and chemistry of second particles 125b (e.g., by precursor generator 130 and microparticle reformation component 140 of FIG. 1). Calcinated particles 355b may be generated by calcinating microparticles 345b using calcination component 150 of FIG. 1. The calcination of microparticles 345b may achieve relithiation, metal restoration, and carbon coating of microparticles 345b. Upcycled cathode materials 365b may be generated by performing surface engineering (e.g., surface coating) on calcinated particles 355b (e.g., by surface engineering component 160 of FIG. 1).

[0008] Microparticles 345c may be generated by adding one or more Li precursors, M precursors, etc. to second particles 125b and reforming second particles 125b (e.g., using precursor generator 130 and microparticle reformation component 140 of FIG. 1). Calcinated particles 355c may be generated by calcinating microparticles 345c using calcination component 150 of FIG. 1. The calcination of microparticles 345b may achieve relithiation, metal restoration, and doping of microparticles 345c. Upcycled cathode materials 365c may be generated by performing an additional calcination process on calcinated particles 355c (e.g., using calcination component 150 of FIG. 1).

[0009] Microparticles 345d may be generated by adding one or more Li precursors, M precursors, P precursors, C precursors, etc. to second particles 125b and upgrading the morphology, chemistry composition, and doping of second particles 125b (e.g., using precursor generator 130 and microparticle reformation component 140 of FIG. 1). Calcinated particles 355d may be generated by calcinating microparticles 345d using calcination component 150 of FIG. 1. The calcination of microparticles 345d may achieve crystallization, doping, and carbon coating of microparticles 345d. Upcycled cathode materials 365d may be generated by performing surface engineering (e.g., surface coating) on calcinated particles 355d (e.g., using surface engineering component 160 of FIG. 1). [0093] FIGS. 4 and 5 are schematic diagrams illustrating example microparticle generation reactors 400 and 500 in accordance with some embodiments of the present disclosure.

[0094] As shown in FIG. 4, microparticle generation reactor 400 may include a droplet generator 410, a chamber 420, inlets 431 and 433, a powder classification unit 440, and/or any other suitable component for generating microparticles utilizing spray drying processes as described herein.

[0095] A precursor solution may be provided to chamber 420 via inlet 431. Droplet generator 410 may include one or more atomizing spray nozzles and/or any other suitable mechanisms (e.g., a centrifugal droplet generation process) that may produce micronized droplets using the precursors. In chamber 420, the precursor may be pumped at high pressure through the atomizing spray nozzle(s). At the outlet of the micro-droplet generator, the precursor is aerosolized into micronized droplets. Meanwhile, a stream of hot carrier gas may be introduced at the bottom of chamber 420 via inlet 433, causing a vortex from the bottom of chamber 420 to the top of chamber 420. The vortex may create a temperature gradient that is hot at the bottom of the chamber and relatively cool at the top. The size of the droplets generated by microparticle generation reactor 400 may be controlled by adjusting spray parameters, such as pressure, flow rates, nozzle geometry, etc. The particles produced in chamber 420 may be provided to powder classification unit 440 for classification. Powder classification unit 440 may include an airclassifying system or any other suitable system (e.g., screen sieving) that can classify particles by size. Powder classification unit 440 may classify the particles produced in chamber 420 into particles 445a with desired sizes and particles 445b lacking the desired sizes. The particles 445a with the desired sizes may be collected for further processing. The particles 445b lacking the desired sizes may be recycled and reused as precursor feedstock.

[0096] Referring to FIG. 5, microparticle generation reactor 500 may include a droplet generator 510, a chamber 520, inlets 531 and 533, a powder classification unit 540, one or more filters 550, an exhaust system 560, and/or any other suitable component for generating microparticles utilizing spray granulation processes as described herein.

[0097] A precursor solution (e.g., a solution or suspension containing solids) may be sprayed by droplet generator 510 to form droplets in a fluidized bed system. Droplet generator 510 may include one or more atomizing spray nozzles and/or any other suitable mechanisms (e.g., centrifugal droplet generation) that may produce micronized droplets using the precursors. Meanwhile, a stream of hot carrier gas may be introduced at the bottom of chamber 520 via inlet 533, causing a vortex from the bottom of chamber 520 to the top of chamber 520.

[0098] The fast heat exchange between the hot gas phase and the micronized droplets may lead to fast liquid evaporation and the formation of initial cores of nanoparticles and/or microparticles. As additional liquid droplets are introduced into the system, they come into contact with the initial cores. As the surrounding liquid evaporates, the cores increase in size, forming larger particles. This procedure is continuously executed within the fluidized bed, enabling the granulate to grow in a layer-by-layer manner. This layer-by-layer accumulation may produce particles with high density.

[0099] The particles produced in chamber 520 may be provided to powder classification unit 540 for classification. Powder classification unit 540 may include an air-classifying system or any other suitable system (e.g., screen sieving) that can classify particles by size. Powder classification unit 440 may classify the particles produced in chamber 520 into particles with desired sizes and particles lacking the desired sizes. Filters 550 may include a filtration system that may physically separate the solid particles from a solid/gas mixture. Exhaust system 560 may guide reaction exhaust gases away from a controlled reaction. The particles 543 with the desired sizes may be collected for further processing. The particles 541 lacking the desired sizes may be recycled and reused as precursor feedstock.

[00100] FIG. 6 illustrates an example calcination system 600 in accordance with some embodiments of the present disclosure. Calcination system 600 may include a boiling bed system 610 and a plasma calcination system 620. Boiling bed system 610 may include a chamber 613, filters 614, and exhaust 615. Plasma calcination system 620 may include power supply 622, water-cooled walls 623, rapid cooling zone 624, and laminar flow zone 625.

[00101] Power supply 622 may be any suitable electrical device that can supply electric power to an electrical load in plasma reactions. The power supply may convert electric current from a source to the correct voltage, current, and frequency to power the load. Water-cooled walls 623 and rapid cooling zone 624 serve as cooling sections to protect the calcination system 600 from elevated temperatures. Laminar flow zone 625 may enable a type of fluid flow in which the gas/solid fluid travels smoothly or in regular paths.

[00102] A precursor 611 containing microparticles of cathode materials (e.g., first precursor solution 135a and/or microparticles 145 of FIG. 1) may be provided to boiling bed system 610. In the boiling bed, a high-temperature gas stream 612 may enter the boiling bed chamber 613 from the bottom of the boiling bed chamber 613. The hot gas stream can cause the decomposition of the precursor compounds in the particles into oxides or phosphates, which can form strong binding to bind the small nanoparticles inside the particle together and prevent agglomeration due to incomplete decomposition of the precursors. The decomposition temperature and residence time of the particles in the boiling bed chamber provide control of the porosity and morphology of the particles. Continuous airflow may direct the pre-calcinated microparticles 621 to the warm plasma reactor. The internal plasma discharge can increase the particle temperature up to 1500-2000 °C in a short time and form molten microdroplets. The plasma temperature and temperature profile along the particles flow path in this in-line plasma calcination zone will be controlled by various parameters to achieve final well-calcined materials. The relatively high surface area of the entrained powders allows for full calcinating in vastly less time when compared to bulk calcinating in a static furnace.

[00103] After in-situ plasma calcination, there are two channels for the calcinated particles. In the first channel, calcinated particles 626 may be collected for addition post-treatment. In the second channel, the hot gases and powders exit through the bottom of the heating zone, which may become entrained in a high-flow region of the system. The flow rate of carrier gas entrained in high-flow region of the system is much higher than that flows through the spray drying chamber, causing a sudden drop in particle temperature as the heat is dissipated to a much larger amount of gas. Through this high velocity gas stream, the calcinated particles are conveyed up and into a surface engineering reactor as described herein.

[00104] FIG. 7 illustrates an example surface engineering reactor 700 in accordance with some embodiments of the present disclosure. Surface engineering reactor 700 may include a spray coating system 710 and a boiling bed system 750. Spray coating system 710 may include a droplet generator 713, a chamber 715, filters 717, and an exhaust system 719. Boiling bed system 750 may include a boiling bed 753, a powder collector 755, and an exhaust system 757. [00105] Droplet generators 705 may include one or more nozzles and/or any other suitable mechanism for producing a spray of coating precursors 701. The calcinated particles produced by calcination system 600 may be coated by the precursor in chamber 715. Hot gas stream of carrier gas 703 may be introduced into chamber 715 via the bottom of chamber 715. The solution of the precursor sprayed into chamber 715 may cause turbulence and thorough mixing of the particles, resulting in a uniform coating on the surface of the calcinated particles. The carrier gases separated from the previously entrained powders may exit chamber 715 and enter directly into an exhaust system 719. After the particles are coated with the precursor, the coated particles may be carried into boiling bed 753 (also referred to as the second boiling bed). High temperature gas streams 707 may enter boiling bed system 750 from the bottom of chamber 751 and may cause the decomposition of the coating precursors on the particles into oxides to form a uniform surface coating. The coated particles may be collected at powder collector 755.

[00106] The spray coating in surface engineering reactor 700 may produce an optimal surface coating on the calcinated particles. When coating using a solution or a suspension, the liquid serves to transport the solids to the surface of the particles. The coating technologies described herein may enable an optimal retention time of the particles in surface engineering reactor 700, which assures outstanding coating qualities. [00107] FIG. 8A is a flowchart of an example process 800 for upcycling spent batteries in accordance with some embodiments of the present disclosure. Process 800 may be implemented using system 100 of FIG. 1, microparticle generation reactor 400 of FIG. 4, microparticle generation reactor 500 of FIG. 5, calcination system 600 of FIG. 6, and/or surface engineering reactor 700 of FIG. 7.

[00108] At 810, cathode materials of spent batteries may be separated into a plurality of groups of particles of varying sizes and/or shapes. For example, a first group of particles may include first particles of first sizes, and a second group of particles may include second particles of second sizes. The first particles and the second particles may be the first particles 125a and the second particles 125b as described in connection with FIG. 1 above. The cathode materials may be separated by particle separator 120 as described in connection with FIG. 1 above.

[00109] At 820, a first precursor solution may be generated using the first group of particles. The first precursor solution may include at least one of a suspension containing the first group of particles or a solution containing the first group of particles. In some embodiments, The first precursor solution may include at least one of Li OH, LiNO ₃ , Li Ac, Ni(NO ₃ )2, Mn(NO ₃ )2, CO(NO ₃ ) ₂ , C ₂ H ₂ O ₄ Ni, Ni(Ac) ₂ , C ₂ H ₂ O ₄ Mn, Mn(Ac) ₂ , Ci ₂ HioMn ₃ Oi ₄ , C ₂ H ₂ O ₄ Co, Co(Ac) ₂ , or A1(NO ₃ ) ₃ . In some embodiments, the first precursor solution may include a lithium precursor and dopingprecursors. In some embodiments the dopant precursors may include one or more Al dopant precursors, Mg dopant precursors, Ti dopant precursors, Ca dopant precursors, Nb dopant precursors, Zr dopant precursors, W dopant precursors, Te dopant precursors, F dopant precursors, or Mo dopant precursors. The first precursor solution may be generated by precursor generator 130 as described in connection with FIG. 1 above.

[00110] At 830, a second precursor solution may be generated using the second group of particles. The second precursor solution may include at least one of a suspension containing the first group of particles or a solution containing the first group of particles. In some embodiments, the second precursor solution may include at least one of LiOH, LiNO ₃ , Li Ac, Ni(NO ₃ ) ₂ , Mn(NO ₃ ) ₂ , Co(NO ₃ ) ₂ , C ₂ H ₂ O ₄ Ni, Ni(Ac) ₂ , C ₂ H ₂ O ₄ Mn, Mn(Ac) ₂ , Ci ₂ HioMn ₃ Oi ₄ , C ₂ H ₂ O ₄ CO, CO(AC)2, A1(NO ₃ ) ₃ , or dopant precursors In some embodiments, the second precursor solution may include one or more Li precursors, Mn precursors, Co precursors, Al precursors, etc. In some embodiments, the second precursor solution may include one or more Al dopant precursors, Ti dopant precursors, Mg dopant precursors, Ca dopant precursors, Nb dopant precursors, Zr dopant precursors, W dopant precursors, Te dopant precursors, F dopant precursors, or Mo dopant precursors. The second precursor solution may be generated by precursor generator 130 as described in connection with FIG. 1 above. [00111] At 840, first cathode materials may be generated using the first precursor solution. For example, as illustrated in FIG. 8B, the first precursor solution may be calcinated to produce the first calcinated particles at 841. The calcination of the first precursor solution may relithiate and dope the first particles. More particularly, for example, calcination component 150 may produce first calcinated particles 155a using first precursor solution 135a as described in connection with FIGS. 1-2 above.

[00112] At 843, surface engineering may be performed on the first calcinated particles. For example, a spray coating process may be performed by surface engineering component 160 as described in connection with FIGS. 1 and 7 above. The first cathode materials may be first cathode materials 165a as described in connection with FIGS. 1 and 2.

[00113] At 850, second cathode materials may be generated using the second precursor solution. For example, as illustrated in FIG. 8C, a plurality of microparticles may be formed using the second precursor solution at 851. More particularly, for example, microparticle reformation component 140 may generate microparticles 145 using second precursor solutions 135b as described in connection with FIG. 1 above. The microparticles may include one or more calcinated particles 355a, 355b, 355c, and 355d as described in connection with FIG. 3B.

[00114] At 853, the plurality of microparticles may be calcinated to produce second calcinated particles. More particularly, for example, calcination component 150 may produce second calcinated particles 155b using second precursor solutions 135b as described in connection with FIGS. 1-3 above.

[00115] At 855, surface engineering may be performed on the second calcinated particles. The second cathode materials may be and/or include second cathode materials 165b of FIG. 1, upcycled cathode materials 365a, 365b, 365c, 365d of FIG. 3B.

[00116] FIG. 9A illustrates an SEM image of aged NCA lithium-ion cathode materials where severe particle cracking can be observed. Fig. 9C illustrates the morphology-reformed NCA lithium-ion battery cathode material particles, which were derived from the broken nanoparticles depicted in FIG. 9B, achieved under optimized conditions. These secondary particles maintain uniform spherical morphologies with densely packed structures. Within these particles, primary particles are evenly distributed across their cross-section, emphasizing their dense nature. Particle size analysis reveals that 50% of these particles have a diameter of less than 13 pm. The creation of these microscale spherical secondary particles can significantly enhance tap density, proving beneficial for electrode fabrication. The electrochemical performance of the developed NCA cathode materials was assessed using half-cell coin cells. As illustrated in Fig. 9D, the reformed NCA cathode materials display a cycling performance comparable to a commercial NCA sample. [00117] Contrasting with poly crystalline particles, layered NCM materials made of singlecrystal particles, devoid of grain boundaries, reduce interparticle stress during high states of charge and are less prone to particle fracture. Moreover, single-crystal NCM particles are more resistant to harmful electrolyte attacks. FIG. 10B illustrates an SEM image of single-crystal NCM622, regenerated from damaged NCM111 polycrystalline particles using specific annealing processes. The crystal phase of the layered, single-crystal NCM622 is validated by the XRD patterns presented in Fig. 10A. Half-cells were assembled using both commercial poly crystalline NCM622 (PS-NCM622) cathode and the regenerated single-crystal NCM622 (SC-NCM622) cathode. As depicted in FIGS. 10C and 10D, the regenerated SC-NCM622 slightly outperforms the commercial PS-NCM622 in aspects like initial discharge-specific capacity, first coulombic efficiency, and cyclability.

[00118] FIG. 11 A illustrates the aged and purified LFP cathode materials with nanoparticles. Using a carefully chosen precursor suspension (comprising spent LFP nanoparticles, lithium source, solvent, and binder), the spray-dried LiFePCL microparticles, postannealed at 700°C for 5h in an Argon atmosphere, are displayed in FIG. 1 IB. All these particles maintain a spherical morphology with D50 equating to 9.7pm, as shown in FIG. 11C. The specific discharge capacity and cyclability of the original LFP nanoparticle cathode materials compared to the regenerated LFP microparticles cathode materials in a half-cell (vs Li/Li+) at C/5 are presented in FIG. 1 ID. FIG. 1 ID shows that the regenerated LFP cathode material achieves a considerably higher discharge capacity (150 mAh/g) than the original LFP cathode (134 mAh/g), signifying the complete recovery of lithium-ions in the spent LFP crystal structure. [00119] For LMFP regeneration, apart from lithium, extra Mn and P sources are essential to maintain the chemical balance, aiming at LiMno.5Feo.5PO4. Similar to the regenerated LFP microparticles, the regenerated LMFP adopts a spherical form, as shown in FIG. 12 A. The primary particles are densely aggregated, leaving minimal spaces, while the secondary particles are highly spherical with an average diameter of 9.67pm (D50), as portrayed in FIG. 12B. XRD characterizations of both the regenerated LFP microparticles and LMFP microparticles are provided in FIG. 12C. Both samples align well with the diffraction patterns of LiMnPO4 and LiFePO4, both belonging to the Pmnb (62) space group. Notably, no impurity phases were detected, highlighting the high purity of the regenerated products. The electrochemical performances of the regenerated LFP and LMFP cathode materials are showcased in FIG. 12D. While both samples offer a similar discharge capacity of around 150 mAh/g, the regenerated LMFP cathode displays an enhanced energy density compared to the LFP, shifting from 500 Wh/kg to 600 Wh/kg, marking an improvement of approximately 20% due to a higher operating voltage. [00120] For simplicity of explanation, the methods of this disclosure are depicted and described as a series of acts. However, acts in accordance with this disclosure can occur in various orders and/or concurrently, and with other acts not presented and described herein. Furthermore, not all illustrated acts may be required to implement the methods in accordance with the disclosed subject matter. In addition, those skilled in the art will understand and appreciate that the methods could alternatively be represented as a series of interrelated states via a state diagram or events.

[00121] The terms “approximately,” “about,” and “substantially” may be used to mean within ±20% of a target dimension in some embodiments, within ±10% of a target dimension in some embodiments, within ±5% of a target dimension in some embodiments, and yet within ±2% in some embodiments. The terms “approximately” and “about” may include the target dimension.

[00122] In the foregoing description, numerous details are set forth. It will be apparent, however, that the disclosure may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the disclosure.

[00123] The terms “first,” “second,” “third,” “fourth,” etc. as used herein are meant as labels to distinguish among different elements and may not necessarily have an ordinal meaning according to their numerical designation.

[00124] The words "example" or "exemplary" are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the words "example" or "exemplary" is intended to present concepts in a concrete fashion. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X includes A or B" is intended to mean any of the natural inclusive permutations. That is, if X includes A; X includes B; or X includes both A and B, then "X includes A or B" is satisfied under any of the foregoing instances. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Reference throughout this specification to "an implementation" or "one implementation" means that a particular feature, structure, or characteristic described in connection with the implementation is included in at least one implementation. Thus, the appearances of the phrase "an implementation" or "one implementation" in various places throughout this specification are not necessarily all referring to the same implementation. [00125] Whereas many alterations and modifications of the disclosure will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description, it is to be understood that any particular embodiment shown and described by way of illustration is in no way intended to be considered limiting. Therefore, references to details of various embodiments are not intended to limit the scope of the claims, which in themselves recite only those features regarded as the disclosure.