Recycling and upcycling of battery anode materials

Abstract

One or more aspects of this disclosure provide a method for recycling and upcycling battery anode materials. The method includes processing used battery material containing a first anode material, purifying the untreated anode material, and producing a second anode material using the purified untreated anode material. In some embodiments, the first anode material includes graphite. The second anode material includes graphite-silicon composites and / or graphite-silicon oxide composites. The second anode material may be a battery-grade anode material that can be used directly in the electrodes of a new battery.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the interests of U.S. Provisional Patent Application No. 63 / 386,242, “RECYCLING AND UPCYCLING BATTERY ANODE MATERIALS,” filed on 6 December 2022, which is incorporated herein by reference in its entirety.

[0002] Government support statement This invention was made with government support under grant DE-SC0020868 awarded by the Department of Energy. The government has certain rights to this invention.

[0003] This application relates in general to battery recycling, and more specifically to the recycling and upcycling of graphite anode materials for used batteries. [Background technology]

[0004] Lithium-ion batteries (LIBs) are widely used in many electrical devices, vehicles, and other applications. Used LIBs can lead to environmental problems and resource waste. LIBs that have reached the end of their service life can become an important secondary source of various materials used in the manufacture of new batteries. Therefore, by reducing recycling costs and improving recycling rates, the life cycle cost of LIBs can be significantly reduced, material shortages can be avoided, the environmental impact of new material production can be mitigated, and low-cost active materials for the manufacture of new batteries can be provided. With the expected increase in cell production over the next decade, primary scrap from production is another important source of global recycling efforts.

[0005] Most research focuses on recycling metallic materials in cathode electrodes. There are few reports on the recovery and utilization of anode graphite material in used lithium-ion batteries (LIBs). Given the resource scarcity and rising manufacturing costs in modern society, graphite, a common raw material in manufacturing, has broad application value. The recycling and regeneration of anode graphite in used batteries cannot be ignored. [Overview of the project] [Problems that the invention aims to solve]

[0006] However, older materials are typically 5 to 10 years more degraded than current materials. Refurbished anode materials may not meet new market needs due to improvements in electrode material properties and the emergence of new chemicals.

[0007] Developing efficient recycling and upcycling processes to recover anode materials in a high-value form for sale to manufacturers is key to promoting LIB recycling. Efficient anode recycling and upcycling infrastructure could lower the cost of new batteries and increase the use of recycled battery materials.

[0008] Silicon-graphite composites have attracted considerable attention as a potential substitute for graphite in commercially available lithium-ion batteries (LIBs). However, these materials face challenges in addressing the volume expansion of silicon, a significant problem that can impair battery performance and lifespan. Used graphite has emerged as a promising candidate for the low-cost production of high-performance silicon-graphite composites. Its porous structure, when refined to achieve the desired pore uniformity and density and combined well with silicon, can effectively mitigate the volume expansion of silicon. [Means for solving the problem]

[0009] The following is a simplified overview of the Disclosure to provide a basic understanding of some aspects of the Disclosure. This overview is not a comprehensive overview of the Disclosure. It is not intended to identify the main or important elements of the Disclosure, nor to describe the scope of any particular embodiment of the Disclosure or the claims. Its sole purpose is to present some of the concepts of the Disclosure in a simplified form as a prelude to the more detailed explanations that will be presented later.

[0010] According to some embodiments of the present disclosure, a method for battery recycling is provided. The method comprises purifying an untreated anode material comprising a first anode material, and producing a second anode material using the purified untreated anode material by synthesizing a second anode material using the first anode material and one or more silicon-containing precursors. The untreated anode material is produced from used batteries or other graphite sources. The first anode material comprises graphite. The second anode material comprises a graphite-silicon composite and / or a graphite-silicon oxide composite.

[0011] In some embodiments, the method further comprises producing untreated anode material by separating a plurality of components of spent battery material, the plurality of components of spent battery material including untreated anode material and untreated cathode material.

[0012] In some embodiments, purifying the untreated anode material involves removing one or more impurities from the untreated anode material, the impurities comprising at least one of metals, metal oxides, inorganic impurities, or organic impurities.

[0013] In some embodiments, purifying the untreated anode material includes performing a plasma purification treatment to remove inorganic or organic impurities from the untreated anode material.

[0014] In some embodiments, producing a second anode material using a first anode material and one or more silicon-containing precursors includes at least one of coating the first anode material with one or more silicon-containing precursors or embedding the first anode material with one or more silicon-containing precursors.

[0015] In some embodiments, one or more silicon-containing precursors include Si particles having a diameter of 1 nm to 1000 nm.

[0016] In some embodiments, one or more silicon-containing precursors include at least one of trimethylsilanol, hexamethyldisiloxane, hexamethylcyclotrisiloxane, tetramethyldisiloxane, triethylsilanol, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethyldisiloxane, silane, dichlorosilane, trichlorosilane, or silicon tetrachloride.

[0017] In some embodiments, the method further includes treating a second anode material in a heat treatment under a controlled atmosphere.

[0018] In some embodiments, the controlled atmosphere includes at least one of N2 or Ar.

[0019] In some embodiments, producing a second anode material using a purified, untreated anode material further includes surface activation of the purified, untreated anode material before synthesizing the second anode material using the first anode material and one or more silicon-containing precursors.

[0020] In some embodiments, surface activation of a purified, untreated anode material includes adding functional groups to the first anode material.

[0021] In some embodiments, surface activation of the purified untreated anode material further includes producing a porous graphite anode material using the purified untreated anode material.

[0022] In some embodiments, synthesizing a second anode material using a first anode material and one or more precursors containing silicon includes producing the second anode material by treating a surface-activated anode material with one or more precursors containing silicon in a heat treatment.

[0023] In some embodiments, the heat treatment temperature of the heat treatment is between about 700 °C and about 2000 °C. In some embodiments, the atmosphere gas in the heat treatment contains at least one of N2 or Ar.

[0024] In some embodiments, the method further includes regenerating a first anode material contained in the untreated anode material by treating a purified raw material with a heat treatment.

[0025] In some embodiments, the heat treatment temperature of the heat treatment is between about 700 °C and about 2000 °C, and the atmosphere gas of the heat treatment contains at least one of H2, N2 or Ar. In some embodiments, the atmosphere gas further contains one or more of CH4, C2H2, C2H4, C3H6 and C3H8.

[0026] According to one or more aspects of the present disclosure, a system for battery recycling is provided. The system includes a purification module that purifies an untreated anode material containing a first anode material, wherein the untreated anode material is manufactured from a used battery and the first anode material contains graphite, and an anode material generator that produces a second anode material using the purified untreated anode material, wherein the anode material generator synthesizes the second anode material using the first anode material and one or more precursors containing silicon, and the second anode material contains a graphite-silicon composite material.

[0027] In some embodiments, the second anode material includes at least one of a graphite-silicon composite or a graphite-silicon oxide composite.

[0028] In some embodiments, the anode material generator further surface-activates the purified untreated anode material before synthesizing a second anode material using a first anode material and one or more precursors containing silicon. [Brief explanation of the drawing]

[0029] [Figure 1] Figure 1 is a block diagram showing a system for anode recycling and upcycling according to several embodiments of the present disclosure.

[0030] [Figure 2] Figure 2 is a block diagram showing exemplary purification modules according to several embodiments of the present disclosure.

[0031] [Figure 3] Figure 3 is a block diagram showing exemplary anode upcycling modules according to several embodiments of the present disclosure.

[0032] [Figure 4A] Figure 4A shows SEM (scanning electron microscope) images of exemplary untreated anode material, purified untreated anode material, and regenerated first anode material according to several embodiments of the present disclosure. [Figure 4B] Figure 4B shows SEM (scanning electron microscope) images of exemplary untreated anode material, purified untreated anode material, and regenerated first anode material according to several embodiments of the present disclosure. [Figure 4C] Figure 4C shows SEM (scanning electron microscope) images of exemplary untreated anode material, purified untreated anode material, and regenerated first anode material according to several embodiments of the present disclosure.

[0033] [Figure 5A] Figure 5A shows the EDX spectra of exemplary graphite anode materials before purification, according to several embodiments of the present disclosure. [Figure 5B] Figure 5B shows the EDX spectra of exemplary purified graphite anode materials according to several embodiments of the present disclosure.

[0034] [Figure 6A] Figure 6A shows a comparison of the electrochemical properties between commercially available graphite and recycled graphite. [Figure 6B] Figure 6B shows a comparison of the electrochemical properties between commercially available graphite and recycled graphite. [Figure 6C] Figure 6C shows a comparison of the electrochemical properties between commercially available graphite and recycled graphite.

[0035] [Figure 7A] Figure 7A shows SEM images of exemplary upcycled graphite-silicon composites according to several embodiments of the present disclosure.

[0036] [Figure 7B] Figure 7B shows the EDX mapping of exemplary upcycled graphite-silicon composites according to several embodiments of the present disclosure.

[0037] [Figure 8] Figure 8 shows the charge / discharge profile of an exemplary upcycled graphite-silicon composite anode material.

[0038] [Figure 9] Figure 9 is a flowchart illustrating a method for anode recycling and upcycling according to several embodiments of the present disclosure. [Modes for carrying out the invention]

[0039] Aspects of this disclosure provide mechanisms (e.g., systems, apparatus, methods, etc.) for recycling and upcycling anode materials for used batteries. As referred to herein, the battery may be any energy storage device. In some embodiments, the battery may be a lithium-ion battery (LIB). Mechanisms described herein can process old batteries and produce restored and / or upgraded anode materials that can be used for the anode electrodes of new batteries.

[0040] LIB recycling may involve discharging the spent LIB and separating the spent graphite using physical methods such as dismantling, crushing, screening, and other mechanical processing. The separated, untreated graphite anode material may be processed to produce recycled anode material (e.g., by direct regeneration of graphite) and / or upcycled anode material (e.g., by upgrading the graphite anode material to a graphite-based material with additional properties desirable for energy and environmental applications).

[0041] Untreated graphite material obtained by separating it from other components of used batteries may not meet battery industry standards due to impurities and structural defects in the graphite material. Existing technologies for recycling graphite anode material from used batteries typically involve processing the untreated graphite material using wet smelting and / or dry smelting processes. However, both dry and wet smelting processes are energy-intensive processes that can generate environmental pollutants (e.g., furans, dioxins, and highly acidic wastewater).

[0042] This disclosure provides end-to-end processing for anode-to-anode direct recycling and upcycling of aged anode materials. The end-to-end processing may include pretreatment of spent lithium-ion batteries, separation and purification of components of untreated anode materials, and direct regeneration and upgrading of anode materials. The end-to-end processing may further include purification and regeneration processing for direct recycling of aged graphite anode materials. The end-to-end processing may further include surface activation processing to facilitate integration between surface-activated graphite and silicon precursors for direct upcycling to produce Gr-Si composite anode materials.

[0043] According to one or more aspects of this disclosure, a system for the direct recycling and upcycling of battery graphite anode material is provided. The system can process used batteries and produce regenerated and / or upgraded anode material that can be used in the electrodes of new batteries. For example, the system can separate untreated anode material from used battery material. The untreated anode material may contain one or more first anode materials, impurities, etc., contained in the used battery material (e.g., graphite). The untreated anode material may then be purified by removing the impurities. The purified untreated anode material may be processed to produce anode material (battery-grade anode material) that can be used directly in the electrodes of new batteries. For example, the first anode material contained in the purified untreated anode material may be regenerated (e.g., recycled) as battery-grade anode material. In another example, one or more second anode materials may be produced using the first anode material. In some embodiments, the second anode material is one or more graphite-silicon (Gr-Si) composite materials and / or graphite-silicon oxide (Gr-SiO) composite materials synthesized using the first anode material and a silicon-containing precursor. x ) Can include composite materials.

[0044] Gr-Si and Gr-SiO xComposite materials are promising anode materials for commercially available lithium-ion batteries (LIBs). However, existing solutions for manufacturing Gr-Si anode materials cannot provide solutions to reduce the volume expansion of silicon. Used graphite materials can be used for the low-cost manufacturing of high-performance Gr-Si composites. The mechanism described herein can generate high-energy Gr-Si composite anode materials using aged graphite anode materials, enabling anode-to-anode direct upcycling.

[0045] Direct recycling / upcycling of graphite anode materials using the disclosed method enhances the commercial feasibility of lithium-ion batteries, reduces battery costs, and thus accelerates the electrification of transportation and large-scale energy storage for renewable energy. Upcycled Gr-Si composites and / or Gr-SiOx composites can then undergo complementary surface optimizations to facilitate electronic contact, increase speed capability, and improve cycle stability. Thus, the mechanism described herein can enable upcycled "value-added" anodes that selectively utilize the design value of aged graphite while reducing downstream remanufacturing requirements.

[0046] Figure 1 is a schematic diagram showing an example system 100 for battery recycling. As shown, system 100 may include a pre-processing module 110, a component separator 120, and an anode material generator 130. System 100 may include more or fewer modules without loss of generality. For example, two modules may be combined into one module, or one module may be divided into two or more modules.

[0047] The pre-processing module 110 can process used battery material to produce used battery material that has been pre-processed for further processing. For example, the pre-processing module 110 may include a battery disassembly system that can disassemble used batteries to remove packaging materials. Packaging materials (e.g., plastic, metal, etc.) may be recycled. The battery core of a used battery may be disassembled into smaller pieces using a shredder and / or crusher. For example, the battery core of a used battery may be shredded in an N2 environment. In one embodiment, the used battery may be discharged before being processed by the pre-processing module. In some embodiments, pre-processing of used battery material may include removing the electrolyte from the used battery material, collecting packaging plastic and separator membranes, powder desorption for black mass collection, and so on.

[0048] The component separator 120 can process pre-treated spent battery material generated by the pre-treatment module 110 to separate the components of the spent battery material. The separated components of the spent battery material may include untreated cathode material, untreated anode material, current collector metal, separator plastic, electrolyte, etc. The cathode material may include lithium-based layered metal oxides (e.g., LiCoO2, LiNiO2, LiMnO2, LiNiCoMnO2, LiNiCoAlO2, etc.). The untreated anode material may include one or more first anode materials, impurities, etc. (e.g., metal oxides, metals, inorganic impurities, organic impurities, etc.) contained in the spent battery material. The first anode material may be graphite and / or may contain graphite. The component separator 120 may include one or more magnetic separators that can separate metal from the spent battery material, a vibrating screen that can separate the cathode material powder particles and the anode material powder from larger pieces, etc. In some embodiments, the component separator 120 may include one or more reactors for processing pre-treated spent battery material and producing untreated cathode material, untreated anode material, and so on.

[0049] Untreated anode material separated from other components of a used battery may be provided to an anode material generator 130 for processing. The anode material generator 130 may produce one or more anode materials that can be used as electrodes for new batteries (also called "battery-grade anode materials"). For example, the anode material generator 130 may regenerate a first anode material contained in the untreated anode material. In another example, the anode material generator 130 may use the first anode material contained in the untreated anode material to produce one or more second anode materials. In some embodiments, the second anode material is a Gr-Si composite material, Gr-SiO x It may include one or more composite anode materials, such as composite materials.

[0050] As shown in Figure 1, the anode material generator 130 may include a purification module 131, an anode material recycling module 133, and an anode material upcycling module 135. The purification module 131 can remove one or more impurities from the untreated anode material to produce purified anode material (e.g., graphite particles). Examples of impurities may include metallic impurities (e.g., Li, Co, Mn, Ni, Al, Cu, Zn, Fe), metal oxides (e.g., Al2O3, CuO), and impurities containing fluorine (F) and / or phosphorus (P) (e.g., LiF, Li3PO4). In some embodiments, the impurities include cathode material from used battery material. The purification module 131 can perform further plasma purification to remove inorganic or organic impurities from the untreated anode material. In some embodiments, the purification module 131 may include one or more components of a purification module 200, as described below in reference to Figure 2. In some embodiments, the plasma purification process may be carried out using the techniques described in PCT / US2021 / 060502, filed November 23, 2021, entitled “SYSTEMS AND METHODS FOR LITHIUM ION BATTERY CATHODE MATERIAL RECOVERY, REGENERATION, AND IMPROVEMENT,” which is incorporated herein by reference in its entirety.

[0051] The purified anode material can then be processed by the recycling module 133 and / or the upcycling module 135 to produce anode material (battery-grade anode material) that can be used for electrodes in new batteries. The anode material recycling module 133 can regenerate the first anode material contained in the spent battery material. The regenerated first anode material may be battery-grade anode material that can be used for electrodes in new batteries. For example, the anode material recycling module 133 may process graphite anode material in a heat treatment under a controlled atmosphere to produce battery-grade anode material for manufacturing new batteries. In some embodiments, the heat treatment temperature may be between about 700°C and about 2000°C. In certain embodiments, the controlled atmosphere gas may include H2, N2, Ar, etc., and combinations thereof. In some embodiments, the atmosphere gas does not contain oxygen. To increase the bonding strength between the introduced Si compound and the porous graphite host, carbon-containing compounds such as alkanes, alkenes, and alkynes can be introduced into the gas atmosphere as an additional carbon source. Suitable gases include methane (CH4), ethyne (C2H2), ethylene (C2H4), propane (C3H6), and propene (C3H8). These gases can be introduced at concentrations ranging from 0.1% to 20% by volume.

[0052] The anode material upcycling module 135 may produce one or more second anode materials using the first anode material. For example, the anode material upcycling module 135 may use a suitable precursor containing purified graphite material and / or silicon to produce one or more Gr-Si composites and / or Gr-SiO x Composite materials can be produced. In some embodiments, the anode upcycle module 135 may include one or more components of the anode upcycle module 300, as described in relation to Figure 3 below.

[0053] Figure 2 is a block diagram showing an example 200 of a purification module according to several embodiments of the present disclosure. As shown, the purification module 200 may include a pre-purification unit 210, a plasma purification unit 220, and / or any other suitable components for purifying untreated anode material separated from used batteries for further recycling and / or upcycling processes as described herein. The purification module 200 may purify untreated anode material separated from used batteries (e.g., untreated anode material produced by the component separator 120 in Figure 1) to produce purified anode material for further recycling and / or upcycling processes. The untreated anode material may include one or more first anode materials, such as graphite material. The purified anode material may include purified graphite material (e.g., graphite particles).

[0054] The pre-purification unit 210 can remove one or more impurities from the untreated anode material. For example, the pre-purification unit 210 may include one or more magnetic separators that can remove one or more metallic impurities from the separated untreated anode material. As another example, the pre-purification unit 210 may remove one or more metallic and oxide impurities using an acid or base solution. Acids may include, for example, HCl, H2SO4, HNO3, H3PO4, etc. Bases may include, for example, LiOH, NaOH, KOH, NH4OH, etc. As a further example, the pre-purification unit 210 may include an air classification or cyclone separation system that can separate metallic impurities and metallic oxide particles by air classification or cyclone separation under reduced pressure. Air classification or cyclone separation may be performed using a carrier gas containing O2, air, N2, Ar, etc. Examples of metallic impurities include Fe, Al, Cu, etc. Examples of metal oxide impurities include Al2O3, CuO, ZrO2, LiCoO2, LiNiCoMnO2, and LiNiCoAlO2. In some embodiments, the solid material may be reacted with a concentrated base in a pressure vessel, and one or more impurities may be removed by subsequent filtration. In some embodiments, the solid material may be reacted with a concentrated acid, and one or more impurities may be removed by subsequent filtration.

[0055] In some embodiments, impurities on the anode material may also include cathode material. The pre-purification unit 210 can separate the cathode material from the untreated anode material. For example, anode graphite and cathode oxide can be separated by treating the first solid material in a heavy solvent or salt solution. The density of the solution / solvent is such that the density of graphite is 2.3 g / cm³ and the density of cathode oxide is 5.5-7 g / cm³. 3 ) may be between. High-density solutions can be recycled for use in the next batch. Examples of high-density solutions and solvents include ZnBr2, sodium polytungstate, or mixtures of these chemicals in solution.

[0056] The purification unit 220 can further purify the pre-purified anode material produced by the pre-purification unit 210. For example, the plasma purification unit 220 can remove organic impurities (e.g., impurities containing F and / or P) from the pre-purified graphite anode material. In some embodiments, the purification unit 220 may include a plasma reactor. In some embodiments, the purification unit 220 includes one or more plasma reactors, such as those described in PCT / US2021 / 060502, filed November 23, 2021, titled "SYSTEMS AND METHODS FOR LITHIUM ION BATTERY CATHODE MATERIAL RECOVERY, REGENERATION, AND IMPROVEMENT," which is incorporated herein by reference in its entirety. The purification unit 220 can pass the pre-purified anode material through a plasma region into a non-equilibrium plasma having a predetermined plasma power density for a predetermined plasma exposure time. The flow rate, a predetermined solid-to-gas volume ratio, a predetermined plasma power density, and a predetermined plasma exposure time are collectively adjusted to reduce or eliminate physically adsorbed and / or covalently bonded surface impurities on the pre-purified anode material.

[0057] In some embodiments, the predetermined flow velocity is between 2 m / s and 20 m / s. In some embodiments, the predetermined solid-to-gas volume ratio is between 0.001 and 0.1. In some embodiments, the predetermined plasma power density is between 0.3 kW and 30 kW per kilogram of pre-purified aged graphite anode material. In some embodiments, the predetermined plasma exposure time is between 0.05 seconds and 30 seconds. In some embodiments, the carrier gas may include O2, air, N2, Ar, and combinations thereof.

[0058] Figure 3 is a block diagram showing an example 300 of an anode upcycle module according to several embodiments of the present disclosure. As shown, the anode upcycle module 300 may include a surface activation unit 310, a precursor generator 320, a precursor encapsulation unit 330, a heat treatment unit 340, and / or any other suitable components for generating one or more second anode materials using one or more first anode materials (e.g., purified anode materials produced by the purification module 131 and / or the purification module 200). The surface activation unit 310 may be a treatment reactor (e.g., a plasma reactor) for surface treatment to add functional groups to the surface. The precursor generator 320 is a precursor supply unit (e.g., a tank) containing a precursor containing solid, liquid, or gaseous Si. The precursor encapsulation unit 330 is between the graphite and the Si-precursor and a reaction section (e.g., a furnace). The heat treatment unit 340 is for the final Gr-Si or Gr-SiO x It may be a tubular furnace for heat treatment to manufacture composite materials. The second anode material produced by the anode upcycling module 300 is one or more Gr-Si composites and / or Gr-SiO2, which are battery-grade anode materials suitable for new battery manufacturing. x Composite materials may be included. The disclosed anode upcycle module 300 may contain more or fewer units without loss of generality. For example, two units may be combined into one unit, or one unit may be divided into two or more units.

[0059] The surface activation unit 310 may process purified untreated anode material using one or more surface activation methods. As described above, the purified untreated anode material includes one or more first anode materials contained in used battery material. Surface activation treatment may improve the reactivity between the first anode material and a silicon-containing precursor. For example, the surface activation unit 310 may add functional groups (e.g., -OH, -COOH, C=O, etc.) to the surface of the purified first anode material (e.g., purified graphite anode material) to promote the reaction and bonding between the first anode material and other materials used to produce a second anode material (e.g., a silicon-containing precursor and / or material). As a more specific example, the surface activation unit 310 may perform one or more acid treatment processes to incorporate -OH groups onto the surface of the purified first anode material. The acid may include, for example, HCl, H2SO4, HNO3, H3PO4, etc. As another example, the surface activation unit 310 may generate radicals on the surface of the first anode material to improve activity by plasma treatment. In some embodiments, surface activation involves using 5 kg of untreated anode treated with an acid mixture consisting of a sulfuric acid solution with a concentration of 2 mol / liter (2 M H2SO4) and a hydrochloric acid solution with a concentration of 1 mol / liter (1 M HCl) in a total volume of 10 liters. In some embodiments, this reaction may be carried out at a temperature of 60°C for about 1 hour. After the reaction, the solids are filtered, washed, and dried. For further surface activation, these purified anodes can be treated in an alkaline solution. In this step, 5 kg of untreated anode is treated with a sodium hydroxide solution (NaOH) with a concentration of 6 mol / liter (6 M NaOH) using a total volume of 10 liters, at the same temperature of 60°C for a reaction time of 1 hour.

[0060] In some embodiments, the surface activation unit 310 may use a pore-generating agent to treat purified untreated anode material to create a porous structure in the graphite material, thereby producing a porous graphite material. The porous structure in the graphite material can provide additional surface area and / or reaction sites for silicon precursor implantation, as well as more space for volume expansion during charging and discharging. The porous structure can facilitate electrolyte permeability, which can result in a larger electrode-electrolyte interface. This can provide more active sites for electrochemical and electrocatalytic reactions.

[0061] In some embodiments, the production of porous graphite material may involve catalytic gasification of purified graphite material in a reducing gas atmosphere using various metals, salts, and metal oxide catalysts. In some embodiments, the reducing gas may include hydrogen, carbon monoxide, carbon dioxide, vapor, or a combination thereof. In some embodiments, the catalyst may include Ni, Zn, Na, K, FeCl3, Ni(NO3)2, Fe(NO3)3, or a combination thereof. In some embodiments, residual catalyst may be removed from the porous graphite material using an acid solution. An example of this process involves mixing 1.5 kg of purified graphite with 5 liters of nickel(II) nitrate solution (containing 10 grams of Ni(NO3)2·6H2O) and stirring for 2 hours. After filtration and drying, the resulting powder is placed in a tubular furnace and heated to 800°C at a rate of 5°C / min under a nitrogen (N2) atmosphere. Once the temperature stabilizes at 800°C, liquid water is pumped into the furnace at a flow rate of 0.20 ml / min. The reaction is then carried out for about 10 hours.

[0062] In some embodiments, the concentration of the catalyst precursor may be between about 0.1% by weight and about 50% by weight. In some embodiments, the reducing gas concentration may be between about 0.1% by volume and about 20%. In some embodiments, the carrier gas for the reducing gas may include N2, Ar, and combinations thereof. In some embodiments, the pore formation reaction temperature is between about 40°C and about 1000°C.

[0063] In some embodiments, surface activation can be performed by plasma treatment. Plasma treatment may be carried out using dielectric barrier discharge (DBD) electrodes positioned downstream and upstream of the particle and gas mixer, the DBD electrodes being adapted to provide a non-equilibrium plasma for introducing radicals to the particle surface. In some embodiments, plasma treatment may be carried out by the purification unit 220 in Figure 2 as described above. The plasma gas composition may include a single gas or a combination of argon (Ar), oxygen (O2), water vapor (H2O), hydrogen (H2), and small hydrocarbon molecules (e.g., methane (CH4), acetylene (C2H2), propene (C3H4), and propane (C3H6)). Examples of plasma treatment conditions include an untreated anode feed rate of 6 kg / hr, a mixed gas containing 1% O2 in argon, and a gas flow rate of 20 m³. 3 Examples include a discharge rate of 300°C per hour, a gas temperature of 300°C, a plasma discharge power of 6000W, and a residence time of 30 seconds.

[0064] The precursor generator 320 may generate and / or provide one or more suitable precursors for generating a second anode material. The precursors may include, for example, Si-based precursors (e.g., solid precursors, liquid precursors, gaseous precursors, etc. containing Si), surface-activated graphite materials, binders with suitable solvents, etc. In some embodiments, the Si-based precursors may include one or more Si nanoparticles (e.g., Si particles having a diameter of 1 nm to 1000 nm), trimethylsilanol, hexamethyldisiloxane, hexamethylcyclotrisiloxane, tetramethyldisiloxane, triethylsilanol, octamethyltrisiloxane, decamethyltetrasiloxane, etc.

[0065] In some embodiments, the concentration of the Si precursor (e.g., solid Si precursor or liquid Si precursor) may be between about 1 wt% and about 50 wt%. In some embodiments, the binder may include one or more polyvinyl butyral (PVB), polyvinyl alcohol (PVA), polyethylene glycol (PEG). The binder concentration may be between about 0.1 wt% and about 20 wt%. In some embodiments, the solvent may include water, ethanol, methanol, isopropanol, ethylene glycol, etc.

[0066] In some embodiments, the concentration of the gaseous Si precursor may be between about 1 wt% and about 100 wt%. In some embodiments, the Si-based gaseous precursor may include silane, dichlorosilane, trichlorosilane, silicon tetrachloride, etc. and combinations thereof. In some embodiments, the carrier gas of the reducing gas may include N2, Ar, and combinations thereof. In some embodiments, the reaction temperature is between 40°C and 500°C.

[0067] The surface-activated first anode material generated by the surface activation unit 310 may be provided to the precursor encapsulation unit 330 for further processing. The precursor encapsulation unit 330 may use the surface-activated first anode material and the precursor provided by the precursor generator 320 to generate one or more second anode materials. The second anode material may include one or more composite anode materials such as Gr-Si composite materials, Gr-SiO x composite materials, etc. For example, the precursor encapsulation unit 330 may synthesize one or more Gr-Si composite materials by coating the Si precursor on the first anode material and / or embedding the Si precursor in the first anode material. In some embodiments, Gr-Si or Gr-SiO xThe composite material can be synthesized by spray pyrolarity coating. The coating process can be well controlled by adjusting operating parameters, including precursor flow rate, nozzle configuration, processing temperature, and carrier gas. In some embodiments, Gr-Si composites can be synthesized using a sol-gel process, which typically involves removing a remaining liquid (solvent) phase that requires a drying process with considerable shrinkage and densification. The uniformity of the composite material produced by the sol-gel process can be well controlled by adjusting the heating rate, temperature, and stirring rate. In some embodiments, Gr-Si composites can be synthesized using a ball mill process. A ball mill is a type of grinder used to grind or blend materials. In some embodiments, Gr-Si composites can be synthesized by a dry coating process. For example, a hybridization system is used to uniformly coat a graphite material with a Si precursor. The hybridization system can perform surface modification, prepare a composite material of fine particles, and perform precise mixing using a dry powder process. The raw materials are dispersed in a high-speed airflow and processed by mechanical impact force.

[0068] The heat treatment unit 340 can process a second anode material (e.g., a composite anode material) in a controlled atmosphere to produce a battery-grade anode material for new battery manufacturing. In certain embodiments, the heat treatment temperature may be between about 700°C and about 2000°C. In some embodiments, the controlled atmosphere gas may include N2, Ar, and the like.

[0069] Figures 4A, 4B, and 4C show SEM images of exemplary untreated anode material produced by the component separator 120 from a used LIB, purified untreated anode material produced by the purification module 131, and regenerated first anode material produced by the recycling module 133, respectively. As shown in Figure 4A, the untreated anode material separated from the packaging, separator, electrolyte, and current collector of the used LIB contains impurities. After preliminary purification and plasma deep cleaning, purified anode material with a clean surface is obtained. The regenerated first anode material is shown in Figure 4C.

[0070] Figures 5A and 5B show the impurity levels of exemplary untreated anode material before and after purification by the purification module 131, respectively. As shown, the impurity levels of Al and Ti were significantly reduced.

[0071] Half-cells were prepared using directly recycled graphite material and commercially available graphite material as working electrodes, and electrochemical tests were performed at room temperature from 0.01V to 1.50V using lithium metal as the counter electrode. As shown in Figure 6A, the initial discharge ratio capacities of recycled graphite and commercially available graphite samples at a rate of C / 10 reached 342 and 330 mAh / g, respectively. In the cycle performance and rate performance tests shown in Figures 6B and 6C, the capacity retention rate of the recycled graphite samples was equal to or higher than that of the commercially available graphite samples, indicating that the recycled graphite material structure is fully recovered for new battery applications.

[0072] Figure 7A shows SEM and EDX mapping graphs of an exemplary upcycled Gr-Si composite anode material produced by the upcycled module 135 of Figure 3. Figure 7A shows an SEM image of the upcycled Gr-Si composite material produced from a spent LIB containing graphite anode material. Figure 7B shows the EDX mapping of C and Si elements on the sample from Figure 7A. As shown in Figure 7B, the Si precursor is well coated on the surface of the graphite material. As shown, Si is uniformly distributed throughout the graphite grains.

[0073] Half-cells were prepared using directly upcycled Gr-Si composite anode material as the working electrode, and electrochemical tests were performed at room temperature from 0.005 to 3.0 V using lithium metal as the counter electrode. As shown in Figure 8, the initial discharge ratio capacity of the upcycled Gr-Si composite material at a rate of C / 20 reached 655 mAh / g, which is significantly higher than that of the directly recycled graphite anode (342 mAh / g). The upcycled Gr-Si composite material with significantly improved capacity can be widely used as anodes for high-energy battery applications.

[0074] Figure 9 is a flowchart illustrating exemplary methods 900 for anode recycling and upcycling according to several embodiments of the present disclosure.

[0075] In 910, untreated anode material can be produced by processing spent battery material. For example, the pre-treatment module 110 and / or component separator 120 in Figure 1 can pre-treat spent battery material and separate its components (e.g., untreated cathode material, untreated anode material, metal, plastic, Li waste, etc.) as described above. The untreated anode material may consist of one or more first battery materials (e.g., graphite anode material) and one or more impurities (e.g., metal, metal oxide, inorganic impurities, organic impurities, etc.).

[0076] As an example, the size of used battery material (e.g., NCM (nickel-cobalt-manganese)-graphite battery) can be reduced. In some embodiments, the used battery material can be shredded into pieces between 1 cm and 5 cm in size using a shredder in a nitrogen (N2) atmosphere. The shredded battery can be dried in a dryer at a suitable temperature for a suitable period of time to remove the electrolyte. For example, shredded battery weighing about 10 kg can be dried in a dryer at 150°C for 2 hours to remove the electrolyte. Membrane and packaging materials within the used battery material can be removed using one or more density separators. The resulting mixture contains anode and cathode electrode material, specifically powder on the current collector. The anode and cathode powder in the used battery material can then be desorbed in a furnace at a suitable temperature (e.g., 500°C) under a nitrogen stream for a suitable period (e.g., about 1 hour). In some embodiments, the nitrogen stream flow rate is 1 m 3 The time may be / hour. After cooling, the anode powder and cathode powder may be sieved using a vibrating screen separator. The anode material and cathode material can then be separated using a density separator.

[0077] In 920, the untreated anode material may be purified. For example, one or more impurities may be purified and / or removed from the untreated anode material. The impurities may include, for example, metals, metal oxides, inorganic impurities, organic impurities, etc. The impurities may be removed by the purification module 131 in Figure 1 and / or the purification module 200 in Figure 2, as described above. As a more specific example, to remove impurities and improve the quality of the graphite material, 3 kilograms of untreated graphite are subjected to a purification treatment using 1 M H2SO4 at a temperature of 60°C for a period of 2 hours. Once the reaction is complete, the solid material is filtered, washed and dried to ensure its cleanliness and suitability for further processing.

[0078] In some embodiments, the purification of the untreated anode material may further include performing a plasma purification treatment to remove inorganic or organic impurities from the untreated anode material. For example, the purified untreated graphite is activated at a controlled rate of 100 grams / min. A gas stream of 1% O2 in Ar by volume is used at a flow rate of 50 liters / min. The plasma output is set to 6000 watts and the residence time is maintained at 30 seconds. This activation step alters the surface properties of the graphite, improving the reactivity and suitability of the graphite for subsequent processes. In some embodiments, the plasma purification treatment may be carried out using the techniques described in PCT / US2021 / 060502, filed November 23, 2021, entitled “SYSTEMS AND METHODS FOR LITHIUM ION BATTERY CATHODE MATERIAL RECOVERY, REGENERATION, AND IMPROVEMENT,” which is incorporated herein by reference in its entirety.

[0079] In step 930, a second anode material may be produced using the purified, untreated anode material. The second anode material may be a graphite-silicon (Gr-Si) composite material or a graphite-silicon oxide (Gr-SiO) composite material. x )This may include composite materials, etc. For example, in 931, surface activation may be performed on a purified untreated anode material. In some embodiments, the surface activation unit 310 in Figure 3 may perform surface activation on a purified untreated anode material (purified first anode material) as described in relation to Figure 3 above.

[0080] In 933, the second anode material may be synthesized using the first anode material and one or more silicon-containing precursors. In some embodiments, the second anode material may be synthesized using the surface-activated first anode material, in which surface activation is performed on the purified untreated anode material (purified first anode material) before the synthesis of the second anode material. For example, the silicon-containing precursor may be coated on and / or embedded in the surface-activated first anode material. The silicon-containing precursor may include Si particles having a diameter between about 1 nm and about 1000 nm. The precursor may include, for example, trimethylsilanol, hexamethyldisiloxane, hexamethylcyclotrisiloxane, tetramethyldisiloxane, triethylsilanol, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethyldisiloxane, silane, dichlorosilane, trichlorosilane, silicon tetrachloride, and the like. The second anode material can be synthesized by the precursor encapsulation unit 330 in Figure 3, as described in relation to Figure 3 above. In a more specific example, the mixture is prepared by combining 3 kilograms of activated graphite with 250 grams of a Si precursor, such as trimethylsilanol, in 10 liters of aqueous solution. The mixture is vigorously stirred at a speed of 600 rpm for 2 hours while maintaining a temperature of 50°C.

[0081] In 935, the second anode material may be further treated in a heat treatment under a controlled atmosphere to produce a battery-grade anode material for new battery manufacturing. The controlled atmosphere may include N2, Ar, or a combination thereof. The heat treatment temperature is between approximately 700°C and approximately 2000°C. The heat treatment may be carried out by a heat treatment unit 340, for example, as described above in relation to Figure 3. In a more specific example, the mixture is subjected to an annealing treatment at a temperature of 1500°C for a duration of 10 hours. During this process, a continuous nitrogen stream is maintained to maintain an inert atmosphere. Annealing enhances the structural stability and electrochemical properties of the silicon-graphite composite material.

[0082] In some embodiments, the first anode material contained in the untreated anode material can be regenerated by processing the refined raw material in 940. For example, the refined raw material can be processed by heat treatment in the recycling module 133 of Figure 1 as described above.

[0083] For the sake of simplicity, the methods of this disclosure are illustrated and described as a series of actions. However, the actions of this disclosure may occur in various orders and / or simultaneously, and in conjunction with other actions not presented and described herein. Furthermore, not all illustrated actions are required to carry out the methods in accordance with the disclosed subject matter. Moreover, those skilled in the art will understand and recognize that the methods may alternatively be represented as a series of interrelated states via a state diagram or events.

[0084] The terms “approximately,” “about,” and “substantially” may be used in some embodiments to mean within ±20% of the target dimension, within ±10% of the target dimension, within ±5% of the target dimension, and within ±2% of the target dimension. The terms “approximately” and “about” may include the target dimension.

[0085] The above description contains many details. However, it will be clear that this disclosure can be implemented without these specific details. In some cases, well-known structures and devices are shown in block diagram form rather than in detail, in order to avoid obscuring this disclosure.

[0086] The terms "first," "second," "third," and "fourth" used herein refer to labels used to distinguish different elements and do not necessarily imply an order according to their numerical designations.

[0087] The terms “example” or “exemplary” are used herein to mean that they serve as examples, cases, or illustrations. Any aspect or design described herein as “example” or “exemplary” should not necessarily be construed as being preferable or advantageous to other aspects or designs. Rather, the use of the terms “example” or “exemplary” is intended to concretely present a concept. Where used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise specified or as is evident from the context, “X includes A or B” is intended to mean either of the natural inclusive substitutions. That is, “X includes A or B” is satisfied when X includes A, when X includes B, or when X includes both A and B. Furthermore, the articles “a” and “an” as used in this application and the appended claims should generally be construed as meaning “one or more” unless otherwise specified or as is evident from the context that they refer to the singular form. Throughout this specification, any reference to “an implementation” or “one implementation” means that the specific features, structure, or characteristics described in relation to that implementation are included in at least one implementation. Therefore, the appearance of the phrase “an implementation” or “one implementation” in various places throughout this specification does not necessarily refer to the same implementation.

[0088] Many changes and modifications to this disclosure will become apparent to those skilled in the art after reading the foregoing description, but it should be understood that any particular embodiment shown and described as an example is not intended to be considered limiting in any way. Accordingly, references to the details of various embodiments are not intended to limit the claims to enumerate only the features that themselves are considered to be in this disclosure.

Claims

1. A method for recycling and upcycling batteries, A step of purifying an untreated anode material comprising a first anode material, wherein the untreated anode material is manufactured from used battery material, and the first anode material comprises graphite. A step of producing a second anode material using the purified untreated anode material, comprising synthesizing the second anode material using the first anode material and one or more precursors containing silicon, A method characterized by including

2. The method according to claim 1, wherein the second anode material comprises at least one of a graphite-silicon composite or a graphite-silicon oxide composite.

3. The process further includes the step of producing the untreated anode material by separating a plurality of components of the used battery material, The method according to claim 1, wherein the plurality of components of the used battery material include the untreated anode material and the untreated cathode material.

4. The method according to claim 1, wherein the step of purifying the untreated anode material includes removing one or more impurities from the untreated anode material, wherein the impurities include at least one of metals, metal oxides, inorganic impurities, and organic impurities.

5. The step of purifying the aforementioned untreated anode material is Plasma purification is performed to remove inorganic or organic impurities from the untreated anode material, The process involves performing an activation treatment to generate more activated functional groups on the surface of the untreated anode material, The method according to claim 4, including the method described in claim 4.

6. The second anode material is produced using the first anode material and one or more precursors containing silicon. The method according to claim 1, comprising at least one of the following: coating the first anode material with the one or more silicon-containing precursors; and embedding the one or more silicon-containing precursors in the first anode material.

7. The one or more silicon-containing precursors are Si or SiO2 having a diameter of 1 nm to 1000 nm. ｘ The method according to claim 6, comprising particles.

8. The method according to claim 6, wherein the one or more silicon-containing precursors include at least one of trimethylsilanol, hexamethyldisiloxane, hexamethylcyclotrisiloxane, tetramethyldisiloxane, triethylsilanol, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethyldisiloxane, silane, dichlorosilane, trichlorosilane, and silicon tetrachloride.

9. A step of processing the second anode material in a heat treatment under a controlled atmosphere, The method according to claim 1, further comprising:

10. The controlled atmosphere is H ２ , N ２ The method according to claim 9, comprising at least one of and Ar.

11. The method according to claim 1, wherein the step of producing the second anode material using the purified untreated anode material further comprises performing a surface activation on the purified untreated anode material before synthesizing the second anode material using the first anode material and one or more precursors containing silicon.

12. Surface activation is performed on the purified untreated anode material. The method according to claim 11, comprising adding a functional group to the first anode material.

13. The method according to claim 11, further comprising surface activation of the purified untreated anode material to produce a porous graphite anode material using the purified untreated anode material.

14. The second anode material is synthesized using the first anode material and one or more precursors containing silicon. In the heat treatment, the second anode material is produced by treating the surface-activated anode material with one or more precursors containing silicon. The method according to claim 13, including the method described in claim 13.

15. The heat treatment temperature of the heat treatment is between approximately 700°C and approximately 2000°C, and the atmospheric gas in the heat treatment is H ２ , N ２ The method according to claim 14, comprising at least one of and Ar.

16. A step of regenerating the first anode material contained in the untreated anode material by treating the purified untreated anode material with heat treatment, The method according to claim 1, further comprising:

17. The heat treatment temperature of the heat treatment is between approximately 700°C and approximately 2000°C, and the atmospheric gas in the heat treatment is H ２ , N ２ The method according to claim 16, comprising at least one of and Ar.

18. A system for battery recycling, A purification module for purifying an untreated anode material containing a first anode material, wherein the untreated anode material is manufactured from a used battery, and the first anode material contains graphite, An anode material generator that produces a second anode material using the purified untreated anode material, wherein the anode material generator synthesizes the second anode material using the first anode material and one or more precursors containing silicon, and the second anode material contains a graphite-silicon composite material, A system that is equipped with [the following].

19. The second anode material is a Gr-Si composite material and Gr-SiO ｘ The system according to claim 18, comprising at least one of the composite materials.

20. The system according to claim 19, wherein the anode material generator further performs surface activation on the purified untreated anode material before synthesizing the second anode material using the first anode material and one or more precursors containing silicon.

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