Method and system for scalable direct recycling of battery waste

Abstract

The embodiments described in this specification relate to a method for recycling battery waste. In some aspects, the method comprises applying a first heat treatment to the battery waste at a temperature between about 100°C and about 700°C, wherein the first heat treatment decomposes at least about 80 wt% of the binder, separating the electrode material from the current collector, and applying a second heat treatment to the electrode material at a temperature between about 400°C and about 1,200°C to produce a recycled electrode material, wherein the second heat treatment decomposes at least 90 wt% of the binder remaining in the electrode material to produce the recycled electrode material. In some embodiments, the method can include applying a surface treatment to the electrode material to remove surface coating agents and / or surface impurities from the electrode material. In some embodiments, the surface treatment can include applying a solvent to the electrode material.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Application No. 63 / 340,612, filed on May 11, 2022, entitled "Methods and Systems for Scalable Direct Recycling of Battery Waste", the disclosure of which is hereby incorporated by reference in its entirety.

[0002] Technical Field The present disclosure generally relates to systems, devices, and methods for recycling energy storage devices, and more particularly to recycling lithium - ion batteries and their components, including waste generated during manufacturing, use, and disposal.

Background Art

[0003] Background Lithium - ion batteries have high power and high energy density, long cycle life, high potential, and low self - discharge rate. As a result, lithium - ion batteries are generally considered the most promising approach for short - term energy storage and are widely used in household appliances, electric vehicles, and grid energy storage. However, lithium - ion batteries also have several drawbacks, including supply constraints of battery materials, environmental hazardous substances during production or at the end of life, and high manufacturing costs.

Summary of the Invention

Means for Solving the Problems

[0004] Summary The embodiments described in this specification relate to a method for recycling battery waste. In some aspects, the method comprises applying a first heat treatment to the battery waste at a temperature between about 100°C and about 700°C, wherein the first heat treatment decomposes at least about 80 wt% of the binder, separating the electrode material from the current collector, and applying a second heat treatment to the electrode material at a temperature between about 400°C and about 1,200°C to produce a recycled electrode material, wherein the second heat treatment decomposes at least 90 wt% of the binder remaining in the electrode material to produce the recycled electrode material. In some embodiments, the method can include applying a surface treatment to the electrode material to remove a surface coating agent and / or surface impurities from the electrode material. In some embodiments, the surface treatment can include applying a solvent to the electrode material. In some embodiments, the solvent can include citric acid, acetic acid, oxalic acid, ammonia, ammonium hydroxide, ammonium chloride, and / or their chemical derivatives.

[0005] In some embodiments, a system for the direct recycling of battery waste is described. The system can include one or more combinations of the following operations: a heat treatment subsystem, a separation subsystem, a surface treatment subsystem, a relithiation subsystem, a washing subsystem, a chemical purification subsystem, and a flotation subsystem (including combining one or more of the same operations). In some embodiments, the system can provide commercial grade electrode materials such as cathode and anode materials for reuse.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0023] Detailed Description Lithium-ion batteries generate significant amounts of waste during their manufacturing, use, and disposal. To address concerns about the environmental sustainability associated with the continuous consumption of lithium-ion batteries, it is possible to develop effective recycling methods during the manufacture of new lithium-ion batteries to recover materials for reuse, including the recombination of recovered materials. Recycled battery materials can have the advantages of reducing greenhouse gas emissions, energy consumption, and the use of virgin materials in the battery manufacturing process.

[0024] Battery recycling can be carried out by at least three methods: pyrometallurgical recycling, hydrometallurgical recycling, and direct recycling. In pyrometallurgical battery recycling, the batteries and battery waste are directly melted to recover valuable metals such as Co, Ni, and Cu in the form of alloys, usually from the bottom of the melting furnace. Leaching treatment is usually performed to separate the recovered metals.

[0025] Some elements (e.g., Co, Mn, Ni) can be economically recovered from some types of cathode materials containing LiCoO2 (also referred to herein as lithium cobalt oxide or LCO), LiMn2O4 (also referred to herein as lithium manganese oxide or LMO), and LiNi x Mn y Co z O2 (where x + y + z = 1) (also referred to herein as lithium nickel cobalt manganese oxide or NCM) by using smelting. In some embodiments, any one of x, y, or z can be zero. However, LiFe t M 1-tPO4 (where 0 < 1 < t; M = Mn, Ni, Co, V or a metal element, or a combination of several metal elements (LFMP) (also referred to herein as lithium iron phosphate or LFP)) recycling by smelting the cathode is generally not economically advantageous because the metals recovered from LFMP batteries are not of such high value. Furthermore, lithium and aluminum often end up as slag due to melting. Extensive and costly processes are often carried out to separate the metals until they can be used to build new batteries. Additionally, the smelting process itself often generates large amounts of waste gas, thereby increasing the total cost for subsequent waste treatment.

[0026] The hydrometallurgical recycling process separates and / or isolates the battery's constituent materials before further processing. This approach is also applicable to the recycling of nickel-metal hydride (Ni-MH) batteries. In the case of lithium-ion batteries, lithium is ultimately recovered as Li2CO3, and other major materials such as Co, Ni, and Al can also be recovered. In the case of Ni-MH batteries, rare earth metals and nickel can be recovered. Hydrometallurgical recycling does not require high temperatures and large quantities, but such an approach changes the geometry of the battery's cathode material, thereby rendering the cathode material inappropriate for reuse without further processing. Hydrometallurgical recycling is described in more detail in U.S. Patent No. 8,846,225, entitled "Reintroduction of lithium into recycled battery materials," which is hereby incorporated by reference in its entirety.

[0027] The direct recycling of batteries can recover high-value cathode materials, as well as anode materials, current collectors, binders, and electrolytes, compared to the above two methods. The direct recycling method includes non-destructive recycling methods and can maintain the structure, geometry, and electrochemical properties of high-value materials. Direct recycling can be altered to recycle the entire battery, individual battery components, combinations of battery components, battery manufacturing waste, or battery disposal waste. An effective direct recycling process can be flexible for the recycling of various battery materials while maintaining the ability to produce commercially usable recycled materials.

[0028] The systems and methods described herein relate to the direct recycling of batteries and battery waste in an efficient and scalable manner. In this technique, batteries and battery waste are processed through several steps to isolate, purify, and / or regenerate one or more recoverable battery components. These processes are designed to be scalable for recycling large quantities of batteries and battery waste.

[0029] Battery waste can include waste or scrap derived from the battery manufacturing process, which can include any single battery component, any combination of battery components, the entire battery at the end of its useful life, defective batteries, damaged batteries or any other form, or combinations thereof. In some embodiments, the battery waste can include one or more cathode sheets including a cathode material and a cathode current collector (often aluminum or a similar material). In some embodiments, the cathode sheet can further include a binder, a conductive additive such as carbon, an electrolyte, a lithium salt, and / or other functional additives. In some embodiments, the battery waste can include one or more anode sheets including an anode material and an anode current collector (often copper or a similar material). In some embodiments, the anode sheet can further include a binder, a conductive additive such as carbon, an electrolyte, a lithium salt and / or other functional additives. In some embodiments, the battery waste includes a separator, a packaging material, conductive wires and / or other battery components. In some embodiments, the battery waste can be combined together by cutting, crushing, grinding, mixing, or other methods. In some embodiments, the battery waste is a black mass, which can include battery waste that has been crushed, ground, mixed or otherwise combined with some or all of one or more components removed (e.g., removal of the battery housing). As used herein, an anode and / or a cathode can be referred to as an electrode. An anode can include an anode material and an anode current collector. A cathode can include a cathode material and a cathode current collector. An anode material and a cathode material can more generally be referred to as electrode materials.

[0030] In some embodiments, the electrode material is LCO, LMO, NCM, lithium nickel cobalt aluminum oxide (LiNi x Co y Al z O2, where x + y + z = 1), LiNi a Mn b Coc A d O2 (where a + b + c + d = 1 and A = Al, Zr or Mg), LFP, LFMP, graphite, lithium titanate (Li4Ti5O 12 or LTO) or other common compositions or derivatives, or combinations thereof, etc., of common lithium ion battery compositions can be included.

[0031] The recycling method described herein can include one or more of the following operations: heat treatment operation, separation operation, surface treatment operation, relithiation operation, washing operation, chemical purification process and flotation process (including combining one or more of the same operations). In some embodiments, commercial grade cathode and anode materials are obtained by this recycling method. In some embodiments, metal scraps such as copper, aluminum, steel or mixtures thereof are obtained by this recycling method. In some embodiments, organic materials such as carbon, electrolyte, separator, etc. can be isolated and recovered.

[0032] FIG. 1 is a flow diagram of a method 10 for recycling battery waste according to one embodiment. The battery waste can include an electrode material connected to a current collector. The electrode material can include an active material and a binder. In some embodiments, the electrode material can include a conductive material. In some embodiments, the anode and the cathode can be processed separately by method 10. In some embodiments, the anode and the cathode can be processed together by method 10. In some embodiments, the input battery waste can include a cathode sheet and / or an anode sheet (or a mixture thereof) that includes a cathode or an anode (which can in some cases be mixed with additives such as a binder and / or conductive carbon) and a current collector. In some embodiments, the current collector can be composed of aluminum and / or copper. In some embodiments, the battery waste can include other components such as a separator, an electrolyte, a lithium salt, and / or a package. In some embodiments, method 10 can be suitable for the treatment of battery waste containing a cathode, an anode, or a mixture thereof, or a battery supplied as an input for recycling, with or without an electrolyte. In some embodiments, the battery waste is one or more fully or partially assembled batteries (with or without an electrolyte). In some embodiments, the battery waste can first be disassembled, processed into multiple sections, crushed, cut, or be other processes that can expose the components of the battery waste for further processing. In some embodiments, this initial treatment of the battery waste can include a discharging step to remove some or all of the residual stored energy in the battery waste. In some embodiments, this discharging step can be performed using electronic discharging (e.g., resistive discharging, discharging through a conductive slurry or liquid), and / or ionic discharging (e.g., discharging in an ionically conductive solution).

[0033] As shown, method 10 optionally includes, in step 11, a step of cleaning the electrode material to remove the binder, and, in step 12, a step of removing impurities from the electrode material. Method 10 includes, in step 13, a step of applying a heat treatment to decompose the electrode material. Method 10 optionally includes, in step 14, a step of treating the exhaust gas resulting from the first heat treatment. Method 10 further includes, in step 15, a step of separating the electrode material from the current collector. Method 10 optionally includes, in step 16, a step of flotation of the electrode material to separate residual impurities from the electrode material, and, in step 17, a step of applying a surface treatment to the electrode material. Method 10 further includes, in step 18, a step of applying a second heat treatment to purify the recovered electrode material. Method 10 optionally includes a step of treating the exhaust gas resulting from the second heat treatment.

[0034] Step 11 is optional and includes a step of washing the electrode material to remove at least a portion of the binder. By washing using a solvent, at least a portion of the binder is dissolved and removed. Most or all of the binder, current collector, and other large particle battery components are separated from the electrode powder (and any residual material) during this washing process. In some embodiments, the electrode material includes a water-based binder (i.e., soluble in an aqueous solution), and the washing operation can utilize an aqueous solvent (e.g., water, or an alkaline solution with a pH of about 14 or less, about 13 or less, about 12 or less, about 11 or less, about 10 or less, about 9 or less, about 8 or less, or about 7.5 or less, such as those containing LiOH, NaOH, KOH). In some embodiments, the electrode material can include a non-aqueous-based binder (i.e., not soluble in an aqueous solution), and the washing operation can utilize an organic solvent or a non-polar solvent. In some embodiments, the non-polar solvent can include N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc or DMA), cyrene or their derivatives, or any combination thereof. In some embodiments, during washing, at least a portion of the electrode material can be separated from the current collector. In other words, at least a portion of Step 11 can be performed simultaneously with Step 15. In some embodiments, other battery components such as residual carbon and other organics, residual binder, smaller particles of the current collector, or any other components, or combinations thereof, can be present with the electrode material after the washing operation.

[0035] In some embodiments, the washing step can be performed in a controlled gas environment. In some embodiments, the gas environment can be inert. In some embodiments, the gas environment can include N2, Ar, or other similar gases. In some embodiments, the gas environment can include CO2. In some embodiments, the gas environment can be reducing. In some embodiments, the gas environment can include H2, a mixture of Ar and H2, a mixture of N2 and H2, or a mixture of CO2 and CO. In some embodiments, the gas environment can include an oxidizing environment. The oxidizing environment can assist in the removal of organic compounds. In some embodiments, air or other gases described above flow along or through the battery waste during washing. In some embodiments, the gas does not flow along or through the battery waste during washing.

[0036] In some embodiments, the gas environment can include from about 0 volume %, about 1 volume %, about 2 volume %, about 3 volume %, about 4 volume %, about 5 volume %, about 6 volume %, about 7 volume %, about 8 volume %, about 9 volume %, about 10 volume %, about 12 volume %, about 13 volume %, about 14 volume %, about 15 volume %, about 16 volume %, about 17 volume %, about 18 volume %, about 19 volume %, about 20 volume %, about 21 volume %, about 22 volume %, about 23 volume %, about 24 volume %, or about 25 volume % O2 (including all values and ranges therebetween). In some embodiments, the gas environment can include an elevated amount of oxygen. In some embodiments, the gas environment can include pure oxygen, or high-purity oxygen. In some embodiments, the gas environment can include from about 30 volume %, about 35 volume %, about 40 volume %, about 45 volume %, about 50 volume %, about 55 volume %, about 60 volume %, about 65 volume %, about 70 volume %, about 75 volume %, about 80 volume %, about 85 volume %, about 90 volume %, about 95 volume %, or about 100 volume % O2 (including all values and ranges therebetween).

[0037] Step 12 is optional and includes a step of removing impurities from the electrode material. In some embodiments, Step 12 can include removing some, most, or all of the residual metal debris (e.g., Cu and / or Al), such as debris from the current collector. In some embodiments, Step 12 can include a step of modifying the surface of the electrode powder to enable easier or more efficient re-lithiation and / or regeneration. In some embodiments, Step 12 can be performed before a heat treatment step (e.g., Step 13) to enable the removal of impurities such as Cu that would not be removable after the heat treatment step. In such cases, the heat treatment operation can oxidize the components and make them not easily removable by a purification operation. In some embodiments, Step 12 can include the use of a weak acid or weak base as a solvent. In some embodiments, Step 12 can include the use of citric acid, acetic acid, oxalic acid, or a similar acid. In some embodiments, the purification operation uses ammonia or an ammonia-based solution, or a similar solution. In some embodiments, Step 12 can include a step of removing residual copper and / or residual aluminum from the electrode material. Step 12 can include a step of dissolving and removing impurities from the electrode material collected from the washing operation in Step 11. In some embodiments, Step 12 can include a step of utilizing a solvent that dissolves and removes impurities. In some embodiments, Step 12 can utilize an alkaline solution (e.g., a solution containing LiOH, NaOH, and / or KOH).

[0038] In some embodiments, mechanical stirring, mixing techniques, and / or heating may be included to remove impurities from the electrode material. In some embodiments, copper and / or aluminum flakes from the current collector are removed during step 12. In some embodiments, an ammonia-based solution can be used to remove impurities from the electrode material such as copper. Ammonia or an ammonia-based compound (such as ammonium chloride or ammonium hydroxide) can react with copper to dissolve it and thus remove copper as an impurity from the electrode material. In some embodiments, the purification operation can utilize a weakly acidic solution such as acetic acid, citric acid, oxalic acid (or other similar acids) to remove impurities, particularly metal or metal oxide impurities. In some embodiments, the purification operation can utilize other acidic solutions such as nitric acid, sulfuric acid, and / or hydrochloric acid (or other similar acids) to remove impurities, particularly metal or metal oxide impurities. Often, the purification operation can be carefully designed so as not to affect the integrity of the electrode material.

[0039] In some embodiments, the solution used to remove impurities from the electrode material can have a pH of at least about 0, at least about 0.5, at least about 1, at least about 1.5, at least about 2, at least about 2.5, at least about 3, or at least about 3.5. In some embodiments, the solution used to remove impurities from the electrode material can have a pH of about 4 or less, about 3.5 or less, about 3 or less, about 2.5 or less, about 2 or less, about 1.5 or less, about 1 or less, or about 0.5 or less. Combinations of the pH values mentioned above are also possible (e.g., at least about 0 and about 4 or less, or at least about 1 and about 3 or less). In some embodiments, the solution used to remove impurities from the electrode material can have a pH of about 0, about 0.5, about 1, about 1.5, about 2, about 2.5, about 3, about 3.5, or about 4.

[0040] In some embodiments, the solution used to remove impurities from the electrode material can have a pH of at least about 13, at least about 13.1, at least about 13.2, at least about 13.3, at least about 13.4, at least about 13.5, at least about 13.6, at least about 13.7, at least about 13.8, at least about 13.9, at least about 14, at least about 14.1, at least about 14.2, at least about 14.3, at least about 14.4, at least about 14.5, at least about 14.6, at least about 14.7, at least about 14.8, or at least about 14.9. In some embodiments, the solution used to remove impurities from the electrode material can have a pH of about 15 or less, about 14.9 or less, about 14.8 or less, about 14.7 or less, about 14.6 or less, about 14.5 or less, about 14.4 or less, about 14.3 or less, about 14.2 or less, about 14.1 or less, about 14 or less, about 13.9 or less, about 13.8 or less, about 13.7 or less, about 13.6 or less, about 13.5 or less, about 13.4 or less, about 13.3 or less, about 13.2 or less, or about 13.1 or less. Combinations of the pH values mentioned above are also possible (e.g., at least about 13 and about 15 or less, or at least about 13.5 and about 14.5 or less) (including all values and ranges therebetween). In some embodiments, the solution used to remove impurities from the electrode material can have a pH of about 13, about 13.1, about 13.2, about 13.3, about 13.4, about 13.5, about 13.6, about 13.7, about 13.8, about 13.9, about 14, about 14.1, about 14.2, about 14.3, about 14.4, about 14.5, about 14.6, about 14.7, about 14.8, about 14.9, or about 15.

[0041] In some embodiments, the purification operation can have a duration of at least about 30 seconds, at least about 1 minute, at least about 2 minutes, at least about 3 minutes, at least about 4 minutes, at least about 5 minutes, at least about 6 minutes, at least about 7 minutes, at least about 8 minutes, at least about 9 minutes, at least about 10 minutes, at least about 15 minutes, at least about 20 minutes, at least about 25 minutes, at least about 30 minutes, at least about 35 minutes, at least about 40 minutes, at least about 45 minutes, at least about 50 minutes, at least about 55 minutes, at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours, at least about 12 hours, at least about 14 hours, at least about 16 hours, at least about 18 hours, at least about 20 hours, at least about 25 hours or at least about 30 hours. In some embodiments, the purification operation can have a duration of about 31 hours or less, about 26 hours or less, about 21 hours or less, about 19 hours or less, about 17 hours or less, about 15 hours or less, about 13 hours or less, about 11 hours or less, about 10 hours or less, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less, about 2 hours or less, about 1 hour or less, about 55 minutes or less, about 50 minutes or less, about 45 minutes or less, about 40 minutes or less, about 35 minutes or less, about 30 minutes or less, about 25 minutes or less, about 20 minutes or less, about 15 minutes or less, about 10 minutes or less, about 9 minutes or less, about 8 minutes or less, about 7 minutes or less, about 6 minutes or less, about 5 minutes or less, about 4 minutes or less, about 3 minutes or less, about 2 minutes or less or about 1 minute or less. Combinations of the durations mentioned above are also possible (e.g., at least about 30 seconds and about 31 hours or less, or at least about 2 minutes and about 4 minutes or less) (including all values and ranges therebetween).In some embodiments, the purification operation can have a duration of about 30 seconds, about 1 minute, about 2 minutes, about 3 minutes, about 4 minutes, about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 35 minutes, about 40 minutes, about 45 minutes, about 50 minutes, about 55 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 12 hours, about 14 hours, about 16 hours, about 18 hours, about 20 hours, about 25 hours or about 30 hours.

[0042] In some embodiments, the purification operation can be carried out at a temperature of at least about 20°C, at least about 30°C, at least about 40°C, at least about 50°C, at least about 60°C, at least about 70°C, at least about 80°C or at least about 90°C. In some embodiments, the purification operation can be carried out at a temperature of about 100°C or less, about 90°C or less, about 80°C or less, about 70°C or less, about 60°C or less, about 50°C or less, about 40°C or less or about 30°C or less. Combinations of the temperatures mentioned above are also possible (e.g., at least about 20°C and about 100°C or less, or at least about 40°C and about 60°C or less) (including all values and ranges therebetween). In some embodiments, the purification operation can be carried out at a temperature of about 20°C, about 30°C, about 40°C, about 50°C, about 60°C, about 70°C, about 80°C, about 90°C or about 100°C.

[0043] The purification operation can modify and optimize the surface geometry of the electrode material by removing inconvenient surface coating agents or impurities (such as inactive secondary phases) from the electrode material, or by modifying the surface structure or chemical properties of the electrode material. These impurities can form under various circumstances, including but not limited to during battery manufacturing, exposure to various atmospheres or humidity, or during previous operations in the recycling process. By modifying and optimizing the surface geometry of the electrode material during this purification operation, the performance of the recovered or regenerated electrode material can be improved. The modification and optimization of the surface geometry of the electrode material during this purification operation can also assist in easier re-lithiation during subsequent heat treatment operations. The surface modification can make it easier to introduce lithium from the lithium source into the electrode structure.

[0044] In some embodiments, the purification can be performed in a controlled gas environment. In some embodiments, the gas environment can be inert. In some embodiments, the gas environment can include N2, Ar, or other similar gases. In some embodiments, the gas environment can include CO2. In some embodiments, the gas environment can be reducing. In some embodiments, the gas environment can include H2, a mixture of Ar and H2, a mixture of N2 and H2, or a mixture of CO2 and CO. In some embodiments, the gas environment can include an oxidative environment. The oxidative environment can assist in the removal of organic compounds. In some embodiments, air or other aforementioned gases flow along or through the battery waste during purification. In some embodiments, the gas does not flow along or through the battery waste during purification. In some embodiments, the surface treatment can be performed under high gas pressure. In some embodiments, the surface treatment can be performed under low gas pressure.

[0045] In some embodiments, the gas environment can contain from about 0% volume, about 1% volume, about 2% volume, about 3% volume, about 4% volume, about 5% volume, about 6% volume, about 7% volume, about 8% volume, about 9% volume, about 10% volume, about 12% volume, about 13% volume, about 14% volume, about 15% volume, about 16% volume, about 17% volume, about 18% volume, about 19% volume, about 20% volume, about 21% volume, about 22% volume, about 23% volume, about 24% volume, or about 25% volume of O2 (including all values and ranges therebetween). In some embodiments, the gas environment can contain an elevated amount of oxygen. In some embodiments, the gas environment can contain pure oxygen, or high-purity oxygen. In some embodiments, the gas environment can contain from about 30% volume, about 35% volume, about 40% volume, about 45% volume, about 50% volume, about 55% volume, about 60% volume, about 65% volume, about 70% volume, about 75% volume, about 80% volume, about 85% volume, about 90% volume, about 95% volume or about 100% volume of O2 (including all values and ranges therebetween).

[0046] Step 13 includes applying a first heat treatment to decompose the electrode material. The first heat treatment can remove or decompose some or all of some components of the battery waste, including, but not limited to, the binder, conductive additives such as carbon, electrolytes, and / or lithium salts. The first heat treatment operation is performed at a temperature at which most or all of the structure of the electrode material or current collector is maintained. Some current collector materials can be in an oxidized state during the first heat treatment. For example, copper can form copper oxide during the first heat treatment. In some embodiments, the first heat treatment can be performed in a heating chamber (e.g., an oven or furnace). In some embodiments, the first heat treatment operation can also convert a hydrophilic organic material (such as a carbon-based anode material or a conductive organic additive) into a hydrophobic organic material, which can be advantageous for subsequent flotation operations (i.e., Step 16). In some embodiments, the heat treatment in Step 13 can be performed before removing impurities from the electrode material in Step 12. In some embodiments, the heat treatment in Step 13 can be performed after removing impurities from the electrode material in Step 12.

[0047] In some embodiments, the first heat treatment can be performed at a temperature of at least about 100°C, at least about 150°C, at least about 200°C, at least about 250°C, at least about 300°C, at least about 350°C, at least about 400°C, at least about 450°C, at least about 500°C, at least about 550°C, at least about 600°C or at least about 650°C. In some embodiments, the first heat treatment can be performed at a temperature of about 700°C or less, about 650°C or less, about 600°C or less, about 550°C or less, about 500°C or less, about 450°C or less, about 400°C or less, about 350°C or less, about 300°C or less or about 250°C or less. Combinations of the temperatures mentioned above are also possible (e.g., at least about 200°C and about 700°C or less, or at least about 400°C and about 600°C or less) (including all values and ranges therebetween). In some embodiments, the first heat treatment can be performed at a temperature of about 100°C, about 150°C, about 200°C, about 250°C, about 300°C, about 350°C, about 400°C, about 450°C, about 500°C, about 550°C, about 600°C, about 650°C or about 700°C.

[0048] In some embodiments, the first heat treatment is performed on battery waste containing polyvinylidene fluoride (PVDF). The isothermal decomposition of the PVDF binder begins at about 300 - 400°C. The heat treatment can be performed above 400°C to ensure the thermal decomposition of PVDF. The PVDF binder is thermally decomposed at such temperatures and vaporized together with any electrolyte solvent residues present (e.g., EC, DMC, EMC, DEC and PC). Such heat treatment conditions can efficiently burn out the PVDF binder while mostly or completely maintaining the structural integrity and compositional integrity of other battery components such as the electrode material or current collector material.

[0049] In some embodiments, the binder is a water-soluble binder. In some embodiments, the binder is styrene-butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyphosphoric acid (PPA) or derivatives thereof, or mixtures thereof, and is thermally decomposed during the first heat treatment at a temperature above the thermal decomposition temperature of the binder.

[0050] In some embodiments, the first heat treatment can be performed in a controlled gas environment. Various gas environments can react with various battery components in various ways, resulting in various products of the heating operation. In some embodiments, the gas environment is inert. In some embodiments, the gas environment can include N2, Ar, or other similar gases. In some embodiments, the gas environment can include CO2. In some embodiments, the gas environment is a reducing environment. In some embodiments, the gas environment can include H2, a mixture of Ar and H2, a mixture of N2 and H2, or a mixture of CO2 and CO. A reducing environment or an inert environment can prevent certain battery components, such as a copper current collector, from oxidizing. In some embodiments, the gas environment can include an oxidizing environment. An oxidizing environment can assist in the removal of organic compounds. In some embodiments, air or other gases described above are flowed into the heating chamber. In some embodiments, no gas is flowed into the heating chamber.

[0051] In some embodiments, the environment of the heating chamber can include from about 0 volume %, about 1 volume %, about 2 volume %, about 3 volume %, about 4 volume %, about 5 volume %, about 6 volume %, about 7 volume %, about 8 volume %, about 9 volume %, about 10 volume %, about 12 volume %, about 13 volume %, about 14 volume %, about 15 volume %, about 16 volume %, about 17 volume %, about 18 volume %, about 19 volume %, about 20 volume %, about 21 volume %, about 22 volume %, about 23 volume %, about 24 volume %, or about 25 volume % O2 (including all values and ranges therebetween). In some embodiments, the gas environment can include an elevated amount of oxygen. In some embodiments, the gas environment can include pure oxygen, or high-purity oxygen. In some embodiments, the gas environment can include from about 30 volume %, about 35 volume %, about 40 volume %, about 45 volume %, about 50 volume %, about 55 volume %, about 60 volume %, about 65 volume %, about 70 volume %, about 75 volume %, about 80 volume %, about 85 volume %, about 90 volume %, about 95 volume %, or about 100 volume % O2 (including all values and ranges therebetween).

[0052] In some embodiments, the first heat treatment can have a duration of at least about 30 seconds, at least about 1 minute, at least about 2 minutes, at least about 3 minutes, at least about 4 minutes, at least about 5 minutes, at least about 6 minutes, at least about 7 minutes, at least about 8 minutes, at least about 9 minutes, at least about 10 minutes, at least about 15 minutes, at least about 20 minutes, at least about 25 minutes, at least about 30 minutes, at least about 35 minutes, at least about 40 minutes, at least about 45 minutes, at least about 50 minutes, at least about 55 minutes, at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours, at least about 12 hours, at least about 14 hours, at least about 16 hours, at least about 18 hours or at least about 20 hours. In some embodiments, the first heat treatment can have a duration of about 21 hours or less, about 19 hours or less, about 17 hours or less, about 15 hours or less, about 13 hours or less, about 11 hours or less, about 10 hours or less, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less, about 2 hours or less, about 1 hour or less, about 55 minutes or less, about 50 minutes or less, about 45 minutes or less, about 40 minutes or less, about 35 minutes or less, about 30 minutes or less, about 25 minutes or less, about 20 minutes or less, about 15 minutes or less, about 10 minutes or less, about 9 minutes or less, about 8 minutes or less, about 7 minutes or less, about 6 minutes or less, about 5 minutes or less, about 4 minutes or less, about 3 minutes or less, about 2 minutes or less or about 1 minute or less. Combinations of the durations mentioned above are also possible (e.g., at least about 30 seconds and about 21 hours or less, or at least about 2 minutes and about 4 minutes or less) (including all values and ranges therebetween).In some embodiments, the first heat treatment can have a duration of about 30 seconds, about 1 minute, about 2 minutes, about 3 minutes, about 4 minutes, about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 35 minutes, about 40 minutes, about 45 minutes, about 50 minutes, about 55 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 12 hours, about 14 hours, about 16 hours, about 18 hours, about 20 hours or about 21 hours.

[0053] In some embodiments, at least about 80 wt%, at least about 81 wt%, at least about 82 wt%, at least about 83 wt%, at least about 84 wt%, at least about 85 wt%, at least about 86 wt%, at least about 87 wt%, at least about 88 wt%, at least about 89 wt%, at least about 90 wt%, at least about 91 wt%, at least about 92 wt%, at least about 93 wt%, at least about 94 wt%, at least about 95 wt%, at least about 96 wt%, at least about 97 wt%, at least about 98 wt% or at least about 99 wt% of the binder can be removed from the battery waste during the first heat treatment in step 13. In some embodiments, 100 wt% or less, 99 wt% or less, 98 wt% or less, 97 wt% or less, 96 wt% or less, 95 wt% or less, 94 wt% or less, 93 wt% or less, 92 wt% or less, 91 wt% or less or 90 wt% or less, 89 wt% or less, 88 wt% or less, 87 wt% or less, 86 wt% or less, 85 wt% or less, 84 wt% or less, 83 wt% or less, 82 wt% or less or 81 wt% or less of the binder can be removed from the battery waste during the first heat treatment in step 13. Combinations of the weight percentages mentioned above are also possible (e.g., at least about 80 wt% and 100 wt% or less, or at least about 85 wt% and 95 wt% or less) (including all values and ranges therebetween). In some embodiments, about 80 wt%, about 81 wt%, about 82 wt%, about 83 wt%, about 84 wt%, about 85 wt%, about 86 wt%, about 87 wt%, about 88 wt%, about 89 wt%, about 90 wt%, about 91 wt%, about 92 wt%, about 93 wt%, about 94 wt%, about 95 wt%, about 96 wt%, about 97 wt%, about 98 wt%, about 99 wt% or about 100 wt% of the binder can be removed from the battery waste during the first heat treatment in step 13.

[0054] Step 14 is optional and includes a step of treating the exhaust gas resulting from the first heat treatment. In some embodiments, the treating step described above may include a step of purifying the exhaust gas (e.g., by a cleaning operation). In some embodiments, the purification can be by scrubbing (i.e., using a gas scrubber). In some embodiments, the exhaust gas can be purified by a gas cleaning device. After the gas treatment, the cleaned gas can be released to the atmosphere or captured.

[0055] In some embodiments, Step 14 can be used to meet certain environmental standards or to remove the amount of hazardous or undesirable substances discharged from the heat treatment operation. In some embodiments, Step 14 can include a gas cleaning operation. In some embodiments, the cleaning operation removes acidic constituents resulting from the exhaust gas. In some embodiments, the cleaning operation removes organic compounds including volatile organic compounds (VOCs), fluorocarbons, or hydrofluorocarbons. In some embodiments, the cleaning operation utilizes a thermal oxidant to remove VOCs.

[0056] Method 15 includes the step of separating the electrode material from the current collector. During step 15, the battery waste can be separated into one or more components, or groups of components. In some embodiments, this separation is performed by a particle size separation method (such as sieving) by utilizing the difference in particle size between the electrode material and the current collector. In some embodiments, the current collector can be divided into smaller pieces prior to step 15. In some embodiments, the separation of the electrode material from the current collector can be by a physical method. In some embodiments, the physical method can include shaking, sonication, liquid washing / flushing, gas injection, or any combination thereof. In some embodiments, the current collector and the electrode material can be collected individually. In some embodiments, the separated electrode material can include other components such as residual organics (e.g., carbon or carbon compounds) or the current collector (e.g., aluminum or copper). In some embodiments, the separated electrode material can contain a small amount of other components such as residual organics (e.g., carbon or carbon compounds) or the current collector (e.g., aluminum or copper). In some embodiments, the electrode material (along with any additives mixed with the electrode material) and the current collector (or other larger particle battery components) can be physically separated from each other and collected individually. The removal of the binder in the electrode in the previous operation can be advantageous for the efficient separation of the electrode material and the current collector.

[0057] Step 16 is optional and includes a step of beneficiating the electrode material to separate residual impurities. During step 16, the residual impurities are separated from the electrode material based on hydrophobicity using froth flotation. In some embodiments, a mixture of the cathode material and the anode material (if the electrode material includes both) can be separated by a flotation operation. The flotation separation includes a solvent (e.g., a polar solvent such as water) mixed with an enhancer (e.g., kerosene) that promotes the hydrophobicity of other materials and a foaming agent (e.g., long-chain alcohols, 4-methyl-2-pentanol, pine oil). The enhancer preferentially binds to the hydrophobic components. Air is blown into the solvent to generate a froth that mainly includes the enhancer, the foaming agent, and the hydrophobic components. The froth can be separated from the solution by stripping or any other surface collection method. Next, the hydrophilic components are collected individually from the solution. In these cases, the cathode material has different hydrophobicity levels derived from some of the other components. For example, a cathode material such as LiCoO2 tends to be hydrophilic, while some anode materials such as graphite tend to be hydrophobic. Thus, the anode material can be removed from the froth, and the cathode material can be collected from the solution under the froth. In some embodiments, other additives such as a pH regulator (e.g., sodium carbonate, sodium hydroxide, lithium carbonate, and lithium hydroxide), a deagglomerant, and a depressant (used to improve the hydrophilicity of certain compounds, e.g., lime, sodium cyanide, and dextrin) can be used to further facilitate the separation. A further description of the froth flotation process can be found in U.S. Patent No. 11,631,909, filed on November 26, 2019, entitled "Methods and Systems for Scalable Direct Recycling of Batteries" (the " '909 Patent"), the entire disclosure of which is incorporated herein by reference.

[0058] Step 17 is optional and includes applying a surface treatment to the electrode material. The surface treatment can modify and optimize the surface geometry of the electrode material by removing an undesirable surface coating agent or impurities (such as an inert secondary phase) from the electrode material, or by modifying the surface structure or chemical properties of the electrode material. These impurities can form under various circumstances, including but not limited to during battery manufacturing, exposure to various atmospheres or humidity, or previous operations during the recycling process. Modifying and optimizing the surface geometry of the electrode material during this surface treatment operation can improve the performance of the recovered or regenerated electrode material. Modifying and optimizing the surface geometry of the electrode material during this surface treatment operation can also assist in easier re-lithiation during subsequent heat treatment operations. The surface modification can make it easier to introduce lithium from the lithium source into the structure of the electrode. In some embodiments, the surface treatment can include the addition of a weak acid or weak base to the electrode material. In some embodiments, the surface treatment can include the addition of an acid or base to the electrode material. The acid can include acetic acid, citric acid, oxalic acid, malic acid, ascorbic acid, or any combination thereof. The base can include ammonia, LiOH, NaOH, KOH, or any combination thereof.

[0059] In some embodiments, the step of applying the surface treatment to the electrode material can have a duration of at least about 30 seconds, at least about 1 minute, at least about 2 minutes, at least about 3 minutes, at least about 4 minutes, at least about 5 minutes, at least about 6 minutes, at least about 7 minutes, at least about 8 minutes, at least about 9 minutes, at least about 10 minutes, at least about 15 minutes, at least about 20 minutes, at least about 25 minutes, at least about 30 minutes, at least about 35 minutes, at least about 40 minutes, at least about 45 minutes, at least about 50 minutes, at least about 55 minutes, at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours, at least about 12 hours, at least about 14 hours, at least about 16 hours, at least about 18 hours, at least about 20 hours, at least about 25 hours or at least about 30 hours. In some embodiments, the step of applying the surface treatment to the electrode material can have a duration of about 31 hours or less, about 26 hours or less, about 21 hours or less, about 19 hours or less, about 17 hours or less, about 15 hours or less, about 13 hours or less, about 11 hours or less, about 10 hours or less, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less, about 2 hours or less, about 1 hour or less, about 55 minutes or less, about 50 minutes or less, about 45 minutes or less, about 40 minutes or less, about 35 minutes or less, about 30 minutes or less, about 25 minutes or less, about 20 minutes or less, about 15 minutes or less, about 10 minutes or less, about 9 minutes or less, about 8 minutes or less, about 7 minutes or less, about 6 minutes or less, about 5 minutes or less, about 4 minutes or less, about 3 minutes or less, about 2 minutes or less or about 1 minute or less. Combinations of the durations mentioned above are also possible (e.g., at least about 30 seconds and about 31 hours or less, or at least about 2 minutes and about 4 minutes or less) (including all values and ranges therebetween).In some embodiments, the step of applying the surface treatment to the electrode material can have a duration of about 30 seconds, about 1 minute, about 2 minutes, about 3 minutes, about 4 minutes, about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 35 minutes, about 40 minutes, about 45 minutes, about 50 minutes, about 55 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 12 hours, about 14 hours, about 16 hours, about 18 hours, about 20 hours, about 25 hours or about 30 hours.

[0060] In some embodiments, the step of applying the surface treatment to the electrode material can be performed at a temperature of at least about 20°C, at least about 30°C, at least about 40°C, at least about 50°C, at least about 60°C, at least about 70°C, at least about 80°C or at least about 90°C. In some embodiments, the step of applying the surface treatment to the electrode material can be performed at a temperature of about 100°C or less, about 90°C or less, about 80°C or less, about 70°C or less, about 60°C or less, about 50°C or less, about 40°C or less or about 30°C or less. Combinations of the temperatures mentioned above are also possible (e.g., at least about 20°C and about 100°C or less, or at least about 40°C and about 60°C or less) (including all values and ranges therebetween). In some embodiments, the step of applying the surface treatment to the electrode material can be performed at a temperature of about 20°C, about 30°C, about 40°C, about 50°C, about 60°C, about 70°C, about 80°C, about 90°C or about 100°C.

[0061] In some embodiments, the solution applied for surface treatment can have a pH of at least about 5, at least about 6, at least about 7, or at least about 8, at least about 9, at least about 10, or at least about 11. In some embodiments, the solution used to remove impurities from the electrode material can have a pH of about 12 or less, about 11 or less, about 10 or less, about 9 or less, about 8 or less, about 7 or less, or about 6 or less. Combinations of the pH values mentioned above are also possible (e.g., at least about 5 and about 12 or less, or at least about 6 and about 8 or less) (including all values and ranges therebetween). In some embodiments, the solution can have a pH value of about 5, about 6, about 7, about 8, or about 9.

[0062] In some embodiments, the surface treatment can be performed in a controlled gas environment. In some embodiments, the gas environment can be inert. In some embodiments, the gas environment can include N2, Ar, or other similar gases. In some embodiments, the gas environment can include CO2. In some embodiments, the gas environment can be reducing. In some embodiments, the gas environment can include H2, a mixture of Ar and H2, a mixture of N2 and H2, or a mixture of CO2 and CO. In some embodiments, the gas environment can include an oxidative environment. The oxidative environment can assist in the removal of organic compounds. In some embodiments, air or other gases mentioned above flow along or through the battery waste during the surface treatment. In some embodiments, the gas does not flow along or through the battery waste during the surface treatment. In some embodiments, the surface treatment can be performed under high gas pressure. In some embodiments, the surface treatment can be performed under low gas pressure.

[0063] In some embodiments, the gas environment can contain from about 0 volume %, about 1 volume %, about 2 volume %, about 3 volume %, about 4 volume %, about 5 volume %, about 6 volume %, about 7 volume %, about 8 volume %, about 9 volume %, about 10 volume %, about 12 volume %, about 13 volume %, about 14 volume %, about 15 volume %, about 16 volume %, about 17 volume %, about 18 volume %, about 19 volume %, about 20 volume %, about 21 volume %, about 22 volume %, about 23 volume %, about 24 volume %, or about 25 volume % O2 (including all values and ranges therebetween). In some embodiments, the gas environment can contain an elevated amount of oxygen. In some embodiments, the gas environment can contain pure oxygen, or high-purity oxygen. In some embodiments, the gas environment can contain from about 30 volume %, about 35 volume %, about 40 volume %, about 45 volume %, about 50 volume %, about 55 volume %, about 60 volume %, about 65 volume %, about 70 volume %, about 75 volume %, about 80 volume %, about 85 volume %, about 90 volume %, about 95 volume % or about 100 volume % O2 (including all values and ranges therebetween).

[0064] In step 18, the recovery of the electrode material is completed by a second heat treatment step. The second heat treatment can improve the purity of the recovered electrode material. In some embodiments, residual carbon and residual organic compounds can be pyrolyzed and vaporized during step 18. Further, the electrode material may experience lithium loss under various circumstances, including but not limited to during battery manufacturing, exposure to various atmospheres or humidities, or prior operations during the recycling process. In some embodiments, the second heat treatment operation can include a relithiation operation to recover the lithium concentration in the electrode material to a commercially viable stoichiometry. In some embodiments, relithiation can include the step of uniformly mixing the electrode material with a further lithium source (e.g., LiOH, Li2CO3) before, during, and / or after the heat treatment. Next, the relithiation of the active material can be completed by solid-state synthesis during the heat treatment. Such synthesis can be in the form of healing structural damage to the electrode material.

[0065] In some embodiments, the stoichiometric lithium loss of the electrode material before lithiation can be between about 0% and about 10%, between about 10% and about 20%, between about 20% and about 30%, between about 30% and about 40% or between about 40% and about 50%. In some embodiments, the lithium loss of the electrode material before relithiation is quantified electrochemically using common elemental quantification or structural instruments such as inductively coupled plasma mass spectrometry or X-ray diffraction, or by open circuit voltage measurement or capacity measurement. In some embodiments, the delithiation operation can be performed without a second heat treatment operation. In some embodiments, the electrode material can undergo a milling step prior to the second heat treatment operation to reduce the particle size of the electrode material or to break up agglomerates.

[0066] In some embodiments, step 18 can include a delithiation operation to remove excess lithium in the electrode material. In some embodiments, the delithiation operation can include washing the electrode material in a solvent that can remove and dissolve the excess lithium. In some embodiments, the solvent can include water. In some embodiments, the electrode material can be washed in an aqueous solution.

[0067] In some embodiments, the second heat treatment operation in step 18 can be performed in a controlled gas environment. Various gas environments can react with various battery components in various ways to yield various products. In some embodiments, the gas environment can be inert. In some embodiments, the gas environment can include N2, Ar or any other similar gas. In some embodiments, the gas environment can be a reducing gas environment. A reducing or inert environment can support better performance of certain electrode materials such as LFP. In some embodiments, the gas environment can include CO2. In some embodiments, the gas environment can include H2, a mixture of Ar and H2, a mixture of N2 and H2, or a mixture of CO2 and CO.

[0068] In some embodiments, the gas environment can be an oxidizing environment. The oxidizing environment can support better performance of certain electrode materials, such as mixed transition metal cathodes (e.g., various compositions of lithium nickel cobalt manganese oxide). In some embodiments, the oxidizing environment contains oxygen. In some embodiments, the oxidizing environment can contain oxygen at a higher concentration than the oxygen in ambient air. In some embodiments, the oxidizing environment can contain at least about 25 volume %, at least about 30 volume %, at least about 35 volume %, at least about 40 volume %, at least about 45 volume %, at least about 50 volume %, at least about 55 volume %, at least about 60 volume %, at least about 65 volume %, at least about 70 volume %, at least about 75 volume %, at least about 80 volume %, at least about 85 volume %, at least about 90 volume % or at least about 95 volume % oxygen. In some embodiments, the oxidizing environment can contain pure oxygen. In some embodiments, the oxidizing environment can contain at least about 99 volume %, at least about 99.9 volume %, at least about 99.99 volume % or at least about 99.999 volume % oxygen. In some embodiments, a reducing gas, air and / or an oxidizing gas can be flowed into the heating chamber where the second heat treatment is performed during step 18. In some embodiments, no gas is flowed into the heating chamber.

[0069] The second heat treatment operation can be performed at various temperatures and for various lengths of time. These parameters can vary depending on the type of material being processed during this heat treatment operation. In some embodiments, the second heat treatment operation is performed at a temperature of at least about 400°C, at least about 500°C, at least about 600°C, at least about 700°C, at least about 800°C, at least about 900°C, at least about 1,000°C or at least about 1,100°C. In some embodiments, the second heat treatment operation is performed at a temperature of about 1,200°C or less, about 1,100°C or less, about 1,000°C or less, about 900°C or less, about 800°C or less, about 700°C or less, about 600°C or less or about 500°C or less. Combinations of the temperatures mentioned above are also possible (e.g., at least about 400°C and about 1,200°C or less, or at least about 600°C and about 900°C or less) (including all values and ranges therebetween). In some embodiments, the second heat treatment operation can be performed at a temperature of about 400°C, about 500°C, about 600°C, about 700°C, about 800°C, about 900°C, about 1,000°C, about 1,100°C or about 1,200°C.

[0070] In some embodiments, the second heat treatment can have a duration between about 1 hour and about 2 hours, between about 2 hours and about 3 hours, between about 3 hours and about 4 hours, between about 4 hours and about 5 hours, between about 5 hours and about 7 hours, between about 7 hours and about 10 hours, or between about 10 hours and about 15 hours. In some embodiments, the second heat treatment can have a duration of at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours, at least about 11 hours, at least about 12 hours, at least about 13 hours, or at least about 14 hours. In some embodiments, the second heat treatment can have a duration of about 15 hours or less, about 14 hours or less, about 13 hours or less, about 12 hours or less, about 11 hours or less, about 10 hours or less, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less, or about 2 hours or less. Combinations of the durations mentioned above are also possible (e.g., at least about 1 hour and about 15 hours or less, or at least about 4 hours and about 10 hours or less) (including all values and ranges therebetween). In some embodiments, the second heat treatment can have a duration of about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, or about 15 hours.

[0071] In some embodiments, the temperature, duration, and atmosphere of the second heat treatment can depend on the cathode material. For example, an LFP electrode can be regenerated at a temperature between about 450 °C and about 800 °C with a duration between about 1 hour and about 12 hours. Further, an NCM electrode can be regenerated at a temperature between about 600 °C and about 900 °C with a duration between about 3 hours and about 15 hours.

[0072] In some embodiments, the second heat treatment can include a heat treatment operation that includes a re-lithiation process that can be performed by the lithium excess method. The lithium excess method can reduce or eliminate the need to accurately quantify the lithium deficiency of the electrode material before applying the regeneration method 10. This method can include mixing the lithium-deficient electrode material with a lithium source in excess of the stoichiometric lithium deficiency of the electrode material. The electrode material mixed with the excess lithium source can then be subjected to a heat treatment operation. This heat treatment operation can be performed at one or more of the above temperature ranges for the second heat treatment and can enable re-lithiation of the electrode material.

[0073] In some embodiments, the second heat treatment can result in the vaporization of at least about 95 wt%, at least about 96 wt%, at least about 97 wt%, at least about 98 wt%, at least about 99 wt%, at least about 99.5 wt%, at least about 99.9 wt%, at least about 99.99 wt% or at least about 99.999 wt% of the binder originally present in the electrode material before the execution of method 10. In some embodiments, the second heat treatment can result in the vaporization of at least about 95 wt%, at least about 96 wt%, at least about 97 wt%, at least about 98 wt%, at least about 99 wt%, at least about 99.5 wt%, at least about 99.9 wt%, at least about 99.99 wt% or at least about 99.999 wt% of the binder present in the electrode material after the first heat treatment in step 13. In some embodiments, the second heat treatment can result in the vaporization of all or substantially all of the binder originally present in the electrode material before the execution of method 10.

[0074] After the second heat treatment, the electrode material can undergo a washing process in a solvent. The solvent can dissolve and / or remove any excess lithium from the electrode material. In some embodiments, the solvent can include water. In some embodiments, an aqueous solution or a water-based solution can be used to wash the electrode material. In some embodiments, the electrode material can undergo a third heat treatment operation (not shown). This heat treatment operation can complete the regeneration process and improve the performance of the electrode material. In some embodiments, the third heat treatment operation can be performed at the same range of temperatures as the second heat treatment operation described above.

[0075] Step 19 is optional and includes a step of treating the exhaust gas resulting from the second heat treatment. In some embodiments, the step of treating can include a step of purifying the exhaust gas (e.g., by a cleaning operation). In some embodiments, the purification can be by a scrubbing process (i.e., using a gas scrubber). In some embodiments, the exhaust gas can be purified by a gas cleaning device. After the gas treatment, the cleaned gas can be released to the atmosphere or captured.

[0076] In some embodiments, Step 19 can be used to meet certain environmental standards or to remove the amount of hazardous or undesirable substances emitted from the heat treatment operation. In some embodiments, Step 19 can include a gas cleaning operation. In some embodiments, the cleaning operation removes acidic constituents resulting from the exhaust gas. In some embodiments, the cleaning operation removes organic compounds including VOCs, fluorocarbons, or hydrofluorocarbons. In some embodiments, the cleaning operation utilizes a thermal oxidizer to remove VOCs.

[0077] In some embodiments, by method 10, a purified and regenerated cathode material or anode material can be obtained. In some embodiments, by method 10, a purified and regenerated cathode material or anode material can be obtained by isolating cathode materials or anode materials derived from other battery components such as current collectors, separators, packages, electrolytes, lithium salts, or certain additives. In some embodiments, by method 10, commercial grade electrode materials can be obtained without the need for an accurate quantification of the lithium deficiency prior to relithiation. In some embodiments, method 10 can be used to separate, purify, and regenerate cathode powders and / or anode powders derived from other battery waste components.

[0078] In some embodiments, by method 10, functional cathode materials and / or anode materials can be obtained. In some embodiments, current collectors, separators, package materials, and other battery components can undergo further sorting and separation for recovery. In some embodiments, magnetic separation can be used to separate iron-based metals from other materials. In some embodiments, an eddy current separation process can be used to separate non-ferrous metals from other materials. In some embodiments, density-based separation can be used to separate materials of different densities.

[0079] Figures 2A-2B illustrate an example of a muffle furnace 120 for heat treatment of battery waste according to one embodiment. FIG. 2A shows a perspective view of the muffle furnace 120, while FIG. 2B shows a detailed schematic view of the muffle furnace 120. As shown, the muffle furnace 120 includes a gas inlet 121, a gas outlet 122, a thermocouple 123, and a muffle 124. In operation, battery waste or a portion thereof can be placed inside the muffle furnace 120. Gas flows into the muffle furnace 120 via the gas inlet 121 and exits the muffle furnace 120 via the gas outlet 122. The gas can have any of the above compositions with reference to the first heat treatment, the second heat treatment, and / or the third heat treatment of method 10. The thermocouple 123 measures the temperature inside the muffle furnace 120, while the muffle 124 retains heat inside the muffle furnace 120 during operation.

[0080] The flow rate of the gas entering and exiting the muffle furnace 120 can be controlled to affect the gas environment inside the muffle furnace 120. In some embodiments, the gas flow rate entering and exiting the muffle furnace 120 can be at least about 1 SCCM, at least about 5 SCCM, at least about 10 SCCM, at least about 50 SCCM, at least about 100 SCCM, at least about 500 SCCM, at least about 1,000 SCCM, at least about 5,000 SCCM, at least about 10,000 SCCM, at least about 50,000 SCCM, at least about 100,000 SCCM, or at least about 500,000 SCCM. In some embodiments, the gas flow rate entering and exiting the muffle furnace 120 can be about 1,000,000 SCCM or less, about 500,000 SCCM or less, about 100,000 SCCM or less, about 50,000 SCCM or less, about 10,000 SCCM or less, about 5,000 SCCM or less, about 1,000 SCCM or less, about 500 SCCM or less, about 100 SCCM or less, about 50 SCCM or less, about 10 SCCM or less, or about 5 SCCM or less. Combinations of the gas flow rates mentioned above are also possible (e.g., at least about 1 SCCM and about 1,000,000 SCCM or less, or at least about 500 SCCM and about 50,000 SCCM or less) (including all values and ranges therebetween). In some embodiments, the gas flow rate entering and exiting the muffle furnace 120 can be about 1 SCCM, about 5 SCCM, about 10 SCCM, about 50 SCCM, about 100 SCCM, about 500 SCCM, about 1,000 SCCM, about 5,000 SCCM, about 10,000 SCCM, about 50,000 SCCM, about 100,000 SCCM, about 500,000 SCCM, or about 1,000,000 SCCM.

[0081] Figures 3A - 3B illustrate an example of a tubular furnace 220 for heat treatment of battery waste according to one embodiment. Figure 3A shows a perspective view of the tubular furnace 220, while Figure 3B shows a detailed schematic view of the tubular furnace 220. The tubular furnace 220 includes a gas inlet 221 and a gas outlet 222 as shown. In some embodiments, the gas inlet 221 and the gas outlet 222 can be the same as or substantially similar to the gas inlet 121 and the gas outlet 222 as described above with reference to Figures 2A - 2B.

[0082] In some embodiments, a roller hearth kiln (not shown) can be used for the heat treatment operation. The roller hearth kiln can allow gas to flow in and out to enable various gas environments or gas flow rates during the heat treatment. In some embodiments, a rotary kiln can be used for the heat treatment operation. The rotary kiln can allow gas to flow in and out to enable various gas environments or gas flow rates during the heat treatment.

[0083] FIG. 4A is a flowchart of a method 310 for treating battery waste according to one embodiment. In some embodiments, method 310 can include a separation operation performed in a dry mode without the aid of added liquid. As shown, method 310 includes, in step 311, the step of rotary sieving the battery waste, in step 312, the step of vibrating and sieving the battery waste, and, optionally, in step 313, the step of applying an air jet sieve to the battery waste. Method 310 includes the step of collecting fines resulting from the exhaust gas in step 314, the step of applying ultrasonic frequency to the current collector to remove residues in step 315, and the step of treating the electrode material with a grinder and / or mill in step 316.

[0084] Step 311 is optional and includes the step of rotary screening the battery waste. In some embodiments, the rotary screening can be by a trommel screen. The rotary screening step can separate the electrode material from the current collector. In some embodiments, method 310 can include, instead of or in addition to the rotary screening, vibration and ultrasonic screening (step 312), air jet screening (step 313) or other similar separation methods of the battery waste. Step 311 results in two material streams by screening or other similar particle size-based separation, one mainly containing the electrode material (along with any additives mixed with the electrode material), and the other mainly containing the current collector (or other larger particle battery components). In some embodiments, the rotary screening (trommel screen), vibration and ultrasonic screening, and / or air jet screening can be operated without the use of liquids.

[0085] In some embodiments, step 311, step 312 and / or step 313 can generate exhaust gas. Step 314 includes the step of collecting the fines resulting from the exhaust gas. In some embodiments, the waste gas stream can be processed and / or cleaned. In some embodiments, the processing and / or cleaning of the waste gas stream can include collecting the fines by a fines collector. In some embodiments, the waste gas stream processing can include any of the above processes in steps 14 and 19 with respect to FIG. 1.

[0086] The material stream generated from rotary screening, vibrating and screening, and / or air jet screening, which contains most of the current collector (or other larger particle battery components) along with residues, is further processed in step 315 by ultrasonic treatment. The ultrasonic treatment helps to further separate any remaining small particle materials derived from the current collector. In some embodiments, the stream of the current collector can be further separated from other components based on the chemical, physical, and / or ferromagnetic properties of the current collector material. For example, the stream of the current collector can be processed by magnetic separation, eddy current separation, and / or density-based separation. In some embodiments, the stream of the current collector may not be subjected to the ultrasonic treatment separation step, but can undergo separation based on the metallic nature or other physical / chemical properties of the current collector (e.g., separation based on magnetism, eddy current, and / or density).

[0087] In step 316, the electrode material can undergo a grinding process and / or a ball milling process to reduce the particle size and / or reduce the formation of agglomerates of the electrode material. This can result in a smaller particle electrode material for further processing. In some embodiments, before and / or after feeding the electrode material to the grinder and / or mill, residual powder from the fine powder collection derived from the exhaust gas can be added to the smaller particle electrode material stream.

[0088] FIG. 5A is a flow diagram of a method 410 for treating battery waste according to one embodiment. Method 410 is a wet separation method. As shown, method 410 includes, at step 411, washing the battery waste in a stirred wash tank, and, optionally, at step 412, applying ultrasonic vibrations to the battery waste in an ultrasonic tank. The method further includes, at step 413, filtering the electrode powder and decanting the waste liquid stream, optionally, at step 414, cleaning the decanted waste liquid stream, at step 415, drying the filtered electrode powder to form a dried electrode powder, at step 416, optionally supplying the purified waste liquid stream to the stirred wash tank and / or the ultrasonic tank, and at step 417, applying ultrasonic vibrations to the current collector to remove residues.

[0089] In some embodiments, any of steps 411-417 can be performed in a controlled gas environment. In some embodiments, the gas environment can be inert. In some embodiments, the gas environment can include N2, Ar, or other similar gases. In some embodiments, the gas environment can include CO2. In some embodiments, the gas environment can be reducing. In some embodiments, the gas environment can include H2, a mixture of Ar and H2, a mixture of N2 and H2, or a mixture of CO2 and CO. In some embodiments, the gas environment can include an oxidative environment. The oxidative environment can assist in the removal of organic compounds. In some embodiments, air or other gases as described above flow along or through the battery waste during steps 411-417. In some embodiments, the gas does not flow along or through the battery waste during steps 411-417.

[0090] In some embodiments, the gas environment can contain about 0% volume, about 1% volume, about 2% volume, about 3% volume, about 4% volume, about 5% volume, about 6% volume, about 7% volume, about 8% volume, about 9% volume, about 10% volume, about 12% volume, about 13% volume, about 14% volume, about 15% volume, about 16% volume, about 17% volume, about 18% volume, about 19% volume, about 20% volume, about 21% volume, about 22% volume, about 23% volume, about 24% volume, or about 25% volume of O2 (including all values and ranges therebetween). In some embodiments, the gas environment can contain an increased amount of oxygen. In some embodiments, the gas environment can contain pure oxygen, or high-purity oxygen. In some embodiments, the gas environment can contain about 30% volume, about 35% volume, about 40% volume, about 45% volume, about 50% volume, about 55% volume, about 60% volume, about 65% volume, about 70% volume, about 75% volume, about 80% volume, about 85% volume, about 90% volume, about 95% volume, or about 100% volume of O2 (including all values and ranges therebetween).

[0091] Step 411 includes the step of washing battery waste in a stirred washing tank. In some embodiments, the stirred washing tank can contain an added liquid. In some embodiments, the added liquid can contain water and / or a water-based solvent. In some embodiments, the added liquid can contain a non-aqueous solvent such as NMP, DMF, dimethylacetamide (DMAc or DMA), cyrene or its derivatives, or mixtures thereof. In some embodiments, step 411 can be performed in a stirred washing tank, a washing tank utilizing ultrasonic treatment for material deaggregation and agitation, and / or other similar liquid-assisted separation processes.

[0092] In some embodiments, method 410 can include, at step 412, applying ultrasonic vibrations to the battery waste in an ultrasonic bath. In some embodiments, the ultrasonic treatment can be performed at least partially simultaneously with the washing in step 411. In some embodiments, the ultrasonic treatment can be performed in the same container as the washing in step 411. In some embodiments, the ultrasonic treatment can be performed at a location different from the washing in step 411.

[0093] Steps 411 and / or 412 can result in a material stream by sieving or other similar particle size-based separation, one mainly containing the electrode material (along with any additives mixed with the electrode material), and the other mainly containing the current collector (or other larger particle battery components).

[0094] At step 413, the material stream mainly containing the electrode material is sieved while the waste liquid stream is decanted. Step 413 removes the liquid from the electrode material. Step 414, which is optional, includes the step of cleaning the decanted waste liquid stream. In some embodiments, the decanted waste stream can be cleaned by purification, neutralization, filtration, or any combination thereof to produce a clean liquid for reuse.

[0095] Step 415 includes drying the filtered electrode powder to form a dried electrode powder. In some embodiments, the drying can be by oven. In some embodiments, the drying can be by furnace. Step 416, which is optional, includes the step of feeding the purified waste liquid stream to a stirred wash tank and / or an ultrasonic bath (i.e., a wash cell).

[0096] The material stream containing most of the current collector (or other larger particle battery components) along with the residue is further processed by ultrasonic treatment in step 417. In some embodiments, step 417 can include any of the processing steps of step 315 as described above with reference to FIG. 4A.

[0097] FIG. 5B shows an example of a processing apparatus for treating battery waste according to various embodiments. FIG. 5B includes a stirred wash tank 460 and an ultrasonic tank 470 as shown. In some embodiments, the stirred wash tank 460 can be used in step 411 as described above. In some embodiments, the ultrasonic tank 470 can be used in step 412 and / or step 417 as described above.

[0098] FIG. 6 is a flowchart of a method 510 for surface treating an electrode material. Method 510 is for treating dry electrode powder. Method 510 includes, as shown, applying a surface treatment to the electrode material while stirring in step 511, filtering the electrode powder to decant a waste liquid stream in step 512, optionally cleaning the decanted waste liquid stream in step 513, drying the filtered electrode powder to form dry electrode powder in step 514, and optionally applying the cleaned waste liquid stream to the surface treatment in step 515.

[0099] In some embodiments, any of steps 511-515 can be performed in a controlled gas environment. In some embodiments, the gas environment can be inert. In some embodiments, the gas environment can include N2, Ar, or other similar gases. In some embodiments, the gas environment can include CO2. In some embodiments, the gas environment can be reducing. In some embodiments, the gas environment can include H2, a mixture of Ar and H2, a mixture of N2 and H2, or a mixture of CO2 and CO. In some embodiments, the gas environment can include an oxidizing environment. The oxidizing environment can assist in the removal of organic compounds. In some embodiments, air or other gases as described above flow along or through the battery waste during steps 511-515. In some embodiments, the gas does not flow along or through the battery waste during steps 511-515.

[0100] In some embodiments, the gas environment can include from about 0 volume %, about 1 volume %, about 2 volume %, about 3 volume %, about 4 volume %, about 5 volume %, about 6 volume %, about 7 volume %, about 8 volume %, about 9 volume %, about 10 volume %, about 12 volume %, about 13 volume %, about 14 volume %, about 15 volume %, about 16 volume %, about 17 volume %, about 18 volume %, about 19 volume %, about 20 volume %, about 21 volume %, about 22 volume %, about 23 volume %, about 24 volume %, or about 25 volume % O2 (including all values and ranges therebetween). In some embodiments, the gas environment can include an elevated amount of oxygen. In some embodiments, the gas environment can include pure oxygen, or high-purity oxygen. In some embodiments, the gas environment can include from about 30 volume %, about 35 volume %, about 40 volume %, about 45 volume %, about 50 volume %, about 55 volume %, about 60 volume %, about 65 volume %, about 70 volume %, about 75 volume %, about 80 volume %, about 85 volume %, about 90 volume %, about 95 volume %, or about 100 volume % O2 (including all values and ranges therebetween).

[0101] Step 511 includes applying a surface treatment to the electrode material while stirring. In some embodiments, the surface treatment can be performed on the electrode material collected from a separation operation (for example, the separation performed, as described above with reference to FIG. 1, corresponds to step 15). In some embodiments, the surface treatment can be performed on the electrode material collected from another previous operation. In some embodiments, the surface treatment can be performed on the electrode material directly received into the direct recycling process. In the surface treatment operation, the electrode material is washed with a solvent to modify the surface of the electrode material. This modified surface can result in better performance of the electrode material ultimately recovered by the recycling process. In some embodiments, the solvent can include a weak acid (such as acetic acid, citric acid, oxalic acid, etc.).

[0102] In some embodiments, the acid concentration in the solvent can be at least about 1 wt%, at least about 2 wt%, at least about 3 wt%, at least about 4 wt%, at least about 5 wt%, at least about 6 wt%, at least about 7 wt%, at least about 8 wt%, at least about 9 wt%, at least about 10 wt%, at least about 11 wt%, at least about 12 wt%, at least about 13 wt%, at least about 14 wt%, at least about 15 wt%, at least about 16 wt%, at least about 17 wt%, at least about 18 wt% or at least about 19 wt%. In some embodiments, the acid concentration in the solvent can be about 20 wt% or less, about 19 wt% or less, about 18 wt% or less, about 17 wt% or less, about 16 wt% or less, about 15 wt% or less, about 14 wt% or less, about 13 wt% or less, about 12 wt% or less, about 11 wt% or less, about 10 wt% or less, about 9 wt% or less, about 8 wt% or less, about 7 wt% or less, about 6 wt% or less, about 5 wt% or less, about 4 wt% or less, about 3 wt% or less or about 2 wt% or less. Combinations of the acid percentages recited above are also possible (e.g., at least about 1 wt% and about 20 wt% or less, or at least about 2.5 wt% and about 5 wt% or less, or at least about 10 wt% and about 20 wt% or less, or at least about 5 wt% and about 10 wt% or less) (including all values and ranges therebetween). In some embodiments, the acid concentration in the solvent can be about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt% or about 20 wt%.

[0103] The acid concentration dissolves any undesirable surface coating agents of the electrode material, but the leaching of the electrode material itself is limited, and thus can be optimized such that the composition and structure of the bulk electrode material are mostly or completely retained. In some embodiments, the solvent is another stronger acid such as nitric acid, sulfuric acid, hydrochloric acid or other similar acids. In some embodiments, the solid-to-liquid ratio of the electrode material to the solvent can be at least about 2.5 g / 100 mL, at least about 3 g / 100 mL, at least about 4 g / 100 mL, at least about 5 g / 100 mL, at least about 6 g / 100 mL, at least about 7 g / 100 mL, at least about 8 g / 100 mL, at least about 9 g / 100 mL, at least about 10 g / 100 mL, at least about 11 g / 100 mL, at least about 12 g / 100 mL, at least about 13 g / 100 mL, at least about 14 g / 100 mL, at least about 15 g / 100 mL, at least about 16 g / 100 mL, at least about 17 g / 100 mL, at least about 18 g / 100 mL or at least about 19 g / 100 mL. In some embodiments, the solid-to-liquid ratio of the electrode material to the solvent can be about 20 g / 100 mL or less, about 19 g / 100 mL or less, about 18 g / 100 mL or less, about 17 g / 100 mL or less, about 16 g / 100 mL or less, about 15 g / 100 mL or less, about 14 g / 100 mL or less, about 13 g / 100 mL or less, about 12 g / 100 mL or less, about 11 g / 100 mL or less, about 10 g / 100 mL or less, about 9 g / 100 mL or less, about 8 g / 100 mL or less, about 7 g / 100 mL or less, about 6 g / 100 mL or less, about 5 g / 100 mL or less, about 4 g / 100 mL or less or about 3 g / 100 mL or less. Combinations of the solid-to-liquid ratios of the electrode material to the solvent mentioned above are also possible (e.g., at least about 2.5 g / mL and about 20 g / 100 mL or less, or at least about 5 g / 100 mL and about 10 g / 100 mL or less) (including all values and ranges therebetween).In some embodiments, the solid-to-liquid ratio of the electrode material to the solvent can be at least about 2.5 g / 100 mL, about 3 g / 100 mL, about 4 g / 100 mL, about 5 g / 100 mL, about 6 g / 100 mL, about 7 g / 100 mL, about 8 g / 100 mL, about 9 g / 100 mL, about 10 g / 100 mL, about 11 g / 100 mL, about 12 g / 100 mL, about 13 g / 100 mL, about 14 g / 100 mL, about 15 g / 100 mL, about 16 g / 100 mL, about 17 g / 100 mL, about 18 g / 100 mL, about 19 g / 100 mL, or about 20 g / 100 mL.

[0104] In some embodiments, the surface treatment is performed at room temperature. In some embodiments, the surface treatment is performed at an elevated temperature but below the boiling point of the solvent. In some embodiments, the surface treatment is performed under high pressure and can be performed in a pressure-resistant container. These temperatures can be room temperature or up to the boiling point of the solvent at that pressure. In some embodiments, the surface treatment can be performed at about 30°C, about 40°C, about 50°C, about 60°C, about 70°C, about 80°C, about 90°C, about 100°C, about 110°C, about 120°C, about 130°C, about 140°C, about 150°C, about 160°C, about 170°C, about 180°C, about 190°C, or about 200°C (including all values and ranges therebetween). In some embodiments, the surface treatment can be performed at about 0.1 bar (gauge), about 0.3 bar, about 0.4 bar, about 0.5 bar, about 0.6 bar, about 0.7 bar, about 0.8 bar, about 0.9 bar, about 1 bar, about 1.5 bar, about 2 bar, about 2.5 bar, about 3 bar, about 3.5 bar, about 4 bar, about 4.5 bar, about 5 bar, about 5.5 bar, about 6 bar, about 6.5 bar, about 7 bar, about 7.5 bar, about 8 bar, about 8.5 bar, about 9 bar, about 9.5 bar, or about 10 bar (including all values and ranges therebetween).

[0105] In some embodiments, mechanical agitation or stirring in step 511 can be used to improve the contact efficiency and process efficiency. In some embodiments, after completion of the surface treatment, a washing operation follows to remove the residual surface treatment solvent. Step 512 includes the step of filtering the electrode powder and decanting the waste liquid stream from the filtration. This filtration can produce a wet electrode powder.

[0106] Step 513 is optional and includes the step of cleaning the decanted waste liquid stream. In some embodiments, step 513, referring to FIG. 5A, as described above, can include any of the processing parameters of step 414. Step 514 includes the step of drying the filtered electrode powder to form a dry electrode powder. The drying step can remove any residual liquid. In some embodiments, the dry electrode powder can be sieved. Step 515 is optional and includes the step of applying the waste liquid stream after cleaning to the surface treatment. In other words, the waste liquid after cleaning can be added to the solvent used for surface treatment in step 511.

[0107] Figure 7 is a flow diagram of a method 610 for surface treating an electrode material according to one embodiment. Method 610 can be used for wet separation and surface treatment of electrode materials derived from current collectors. Method 610, as shown, optionally includes the step of washing battery waste in a stirred wash tank at step 611 and the step of applying ultrasonic vibrations to the battery waste in an ultrasonic tank at step 612. Method 610 includes the step of applying a surface treatment to the electrode powder at step 613, the step of filtering the electrode powder to decant a waste liquid stream at step 614, optionally the step of cleaning the decanted waste liquid stream at step 615 as needed, the step of drying the filtered electrode powder to form a dried electrode powder at step 616, the step of optionally applying the waste liquid stream to the stirred wash tank and / or the ultrasonic tank at step 617, and the step of optionally applying ultrasonic vibrations to the current collector to remove residues at step 618.

[0108] In some embodiments, the surface treatment can be performed in a controlled gas environment. In some embodiments, the gas environment can be inert. In some embodiments, the gas environment can include N2, Ar, or other similar gases. In some embodiments, the gas environment can include CO2. In some embodiments, the gas environment can be reducing. In some embodiments, the gas environment can include H2, a mixture of Ar and H2, a mixture of N2 and H2, or a mixture of CO2 and CO. In some embodiments, the gas environment can include an oxidative environment. The oxidative environment can assist in the removal of organic compounds. In some embodiments, air or other gases described above flow along or through the battery waste during the surface treatment. In some embodiments, the gas does not flow along or through the battery waste during the surface treatment.

[0109] In some embodiments, the gas environment can contain about 0% volume, about 1% volume, about 2% volume, about 3% volume, about 4% volume, about 5% volume, about 6% volume, about 7% volume, about 8% volume, about 9% volume, about 10% volume, about 12% volume, about 13% volume, about 14% volume, about 15% volume, about 16% volume, about 17% volume, about 18% volume, about 19% volume, about 20% volume, about 21% volume, about 22% volume, about 23% volume, about 24% volume, or about 25% volume of O2 (including all values and ranges therebetween). In some embodiments, the gas environment can contain an increased amount of oxygen. In some embodiments, the gas environment can contain pure oxygen, or high-purity oxygen. In some embodiments, the gas environment can contain about 30% volume, about 35% volume, about 40% volume, about 45% volume, about 50% volume, about 55% volume, about 60% volume, about 65% volume, about 70% volume, about 75% volume, about 80% volume, about 85% volume, about 90% volume, about 95% volume, or about 100% volume of O2 (including all values and ranges therebetween).

[0110] In some embodiments, steps 611 and 612 can be at least partially performed simultaneously to separate the electrode material from the current collector. The cleaning of the battery waste in a stirred cleaning tank and / or the application of ultrasonic vibrations to the battery waste in an ultrasonic tank can be at least partially performed simultaneously. Steps 611 and / or 612 utilize liquid assistance to separate the electrode material from the current collector. After the electrode material is separated from the current collector, the electrode material can be processed in the same or substantially the same manner as the processing of method 510 as described above with reference to FIG. 6.

[0111] Step 613 includes the step of applying a surface treatment to the electrode powder. In some embodiments, step 613 may be the same as or substantially similar to step 511 as described above with reference to FIG. 6. Step 614 includes the step of filtering the electrode powder and decanting the waste liquid stream. In some embodiments, step 614 may be the same as or substantially similar to step 512 as described above with reference to FIG. 6. Step 615 is optional and includes the step of cleaning the decanted waste liquid stream. In some embodiments, step 615 may be the same as or substantially similar to step 513 as described above with reference to FIG. 6. Step 616 includes the step of drying the filtered electrode powder to form a dried electrode powder. In some embodiments, step 616 may be the same as or substantially similar to step 514 as described above with reference to FIG. 6.

[0112] Step 617 is optional and includes the step of applying the cleaned waste liquid stream to a stirred wash tank and / or an ultrasonic tank. In some embodiments, step 617 may be the same as or substantially similar to step 515 as described above with reference to FIG. 6. The cleaned waste liquid stream can provide a solvent suitable for agitation and / or ultrasonic treatment. Step 618 is optional and includes the step of applying ultrasonic vibrations to the current collector and removing residues from the current collector. In some embodiments, step 618 may be the same as or substantially similar to step 417 as described above with reference to FIG. 5A.

[0113] FIG. 8 is a flow diagram of a method 710 for producing a recycled electrode material according to one embodiment. Method 710 can be used to recycle a wide variety of battery waste as described above. In some embodiments, the battery waste includes LCO, cathode scrap of NCM waste, NCA waste cathode scrap, LFP waste cathode scrap, and / or LTO waste anode scrap. In some embodiments, the battery waste can include cathode material and / or anode material (with or without additives and / or binders) on a current collector. In some embodiments, the battery waste can include other battery components such as packages or separators. In some embodiments, the battery waste can include electrolytes or lithium salts.

[0114] As shown, method 710 includes, in step 711, applying a first heat treatment to decompose the electrode material, optionally, in step 712, treating the exhaust gas resulting from the first heat treatment, in step 713, separating the electrode material from other battery waste, optionally, in step 714, applying a surface treatment to the electrode material, in step 715, filtering and drying the electrode material and decanting the waste liquid stream, in step 716, cleaning the decanted waste liquid stream, in step 717, milling and mixing the electrode material, and in step 718, applying a second heat treatment to purify the recovered electrode material.

[0115] Step 711 includes applying a first heat treatment to decompose the electrode material. In some embodiments, the first heat treatment can partially or completely disintegrate battery waste components such as binders, electrolytes, lithium salts, or packaging materials. In some embodiments, step 711 can have any of the processing parameters as step 13, as described above with reference to FIG. 1. In step 712, the exhaust gas resulting from the first heat treatment is processed as necessary. In some embodiments, the exhaust gas is scrubbed, cleaned, and / or filtered to remove any hazardous or undesirable compounds (e.g., hydrogen fluoride, hydrofluorocarbons, fluorocarbons, and / or VOCs) and exhaust a cleaner gas. In some embodiments, step 712 can have any of the processing parameters of step 14, as described above with reference to FIG. 1.

[0116] Step 713 includes separating the electrode material from other battery waste (e.g., current collectors, packages, separators). In some embodiments, the separation of the electrode material from other battery waste can include dry separation methods, including rotary screening, vibration, ultrasonic screening, and / or air jet screening. In some embodiments, the separation of the electrode material from other battery waste can include wet separation methods, including agitated washing and / or ultrasonic treatment. In some embodiments, step 713 can have any of the processing parameters of step 15, as described above with reference to FIG. 1.

[0117] Step 714 is optional and includes applying a surface treatment to the electrode material. The surface treatment modifies the surface properties of the electrode material. In some embodiments, step 714 can have any of the processing parameters of step 17 as described above with reference to FIG. 1. Step 715 includes filtering and drying the electrode material and decanting the waste liquid stream. In some embodiments, step 715 can include any of the processing parameters of step 614 and step 616 as described above with reference to FIG. 7.

[0118] Step 716 includes cleaning the decanted waste liquid stream. In some embodiments, the waste liquid stream can include an aqueous solution. In some embodiments, the aqueous solution can be neutralized and precipitated to produce a clean water stream. In some embodiments, step 716 can include any of the processing parameters of step 513 as described above with reference to FIG. 6. Step 717 includes milling and mixing the electrode material. In some embodiments, the electrode material can be milled and mixed after the surface treatment in step 714. In some embodiments, if it is determined that lithium is deficient, a predetermined amount of a lithium source can be mixed with the electrode material. In some embodiments, an additional washing process can be applied to remove excess lithium from the electrode material.

[0119] Step 718 includes applying a second heat treatment to purify the recovered electrode material. In some embodiments, step 718 can produce a commercial grade recycled electrode powder. In some embodiments, the second heat treatment can be performed at a temperature of at least about 500°C, at least about 510°C, at least about 520°C, at least about 530°C, at least about 540°C, at least about 550°C, at least about 560°C, at least about 570°C, at least about 580°C, at least about 590°C, at least about 600°C, at least about 610°C, at least about 620°C, at least about 630°C, at least about 640°C, at least about 650°C, at least about 660°C, at least about 670°C, at least about 680°C or at least about 690°C. In some embodiments, the second heat treatment can be performed at a temperature of about 700°C or less, about 690°C or less, about 680°C or less, about 670°C or less, about 660°C or less, about 650°C or less, about 640°C or less, about 630°C or less, about 620°C or less, about 610°C or less, about 600°C or less, about 590°C or less, about 580°C or less, about 570°C or less, about 560°C or less, about 550°C or less, about 540°C or less, about 530°C or less, about 520°C or less or about 510°C or less. Combinations of the temperatures mentioned above are also possible (e.g., at least about 500°C and about 700°C or less, or at least about 550°C and about 650°C or less) (including all values and ranges therebetween). In some embodiments, the second heat treatment can be performed at a temperature of about 500°C, about 510°C, about 520°C, about 530°C, about 540°C, about 550°C, about 560°C, about 570°C, about 580°C, about 590°C, about 600°C, about 610°C, about 620°C, about 630°C, about 640°C, about 650°C, about 660°C, about 670°C, about 680°C, about 690°C or about 700°C.

[0120] In some embodiments, the electrode material recovered from the second heat treatment can include LFP. In some embodiments, the second heat treatment can be performed in an inert environment (e.g., including nitrogen gas). In some embodiments, the second heat treatment can have a duration of at least about 3 hours, at least about 3.5 hours, at least about 4 hours, at least about 4.5 hours, at least about 5 hours, or at least about 5.5 hours. In some embodiments, the second heat treatment can have a duration of about 6 hours or less, about 5.5 hours or less, about 5 hours or less, about 4.5 hours or less, about 4 hours or less, or about 3.5 hours or less. Combinations of the durations mentioned above are also possible (e.g., at least about 3 hours and about 6 hours or less, or at least about 3.5 hours and about 5.5 hours or less) (including all values and ranges therebetween). In some embodiments, the second heat treatment can have a duration of about 3 hours, about 3.5 hours, about 4 hours, about 4.5 hours, about 5 hours, about 5.5 hours, or about 6 hours.

[0121] In some embodiments, an electrode material containing nickel or cobalt (such as LCO or NCM) can be treated by a second heat treatment operation at a temperature of at least about 700 °C, at least about 750 °C, at least about 800 °C, at least about 850 °C, at least about 900 °C, or at least about 950 °C. In some embodiments, the second heat treatment operation can be performed at a temperature of about 1,000 °C or less, about 950 °C or less, about 900 °C or less, about 850 °C or less, about 800 °C or less, or about 750 °C or less. Combinations of the temperatures mentioned above are also possible (e.g., at least about 700 °C and about 1,000 °C or less, or at least about 800 °C and about 900 °C or less) (including all values and ranges therebetween). In some embodiments, the second heat treatment operation can be performed in air or in an elevated oxygen environment.

[0122] In some embodiments, the second heat treatment can have a duration of at least about 8 hours, at least about 8.5 hours, at least about 9 hours, at least about 9.5 hours, at least about 10 hours, at least about 10.5 hours, at least about 11 hours, at least about 11.5 hours, at least about 12 hours, at least about 12.5 hours, at least about 13 hours, at least about 13.5 hours, at least about 14 hours or at least about 14.5 hours. In some embodiments, the second heat treatment can have a duration of about 15 hours or less, about 14.5 hours or less, about 14 hours or less, about 13.5 hours or less, about 13 hours or less, about 12.5 hours or less, about 12 hours or less, about 11.5 hours or less, about 11 hours or less, about 10.5 hours or less, about 10 hours or less, about 9.5 hours or less, about 9 hours or less or about 8.5 hours or less. Combinations of the durations mentioned above for the second heat treatment time are also possible (e.g., at least about 8 hours and about 15 hours or less, or at least about 10 hours and about 12 hours or less) (including all values and ranges therebetween). In some embodiments, the second heat treatment can have a duration of about 8 hours, about 8.5 hours, about 9 hours, about 9.5 hours, about 10 hours, about 10.5 hours, about 11 hours, about 11.5 hours, about 12 hours, about 12.5 hours, about 13 hours, about 13.5 hours, about 14 hours, about 14.5 hours or about 15 hours.

[0123] FIG. 9 is a decision flowchart of a method 810 for processing an electrode material according to one embodiment. In some embodiments, method 810 can be used for the direct recycling of battery waste. In some embodiments, method 810 can be used to recycle battery waste containing graphite waste anodes.

[0124] As shown, method 810 includes, at step 801, determining whether the binder of the electrode is water-soluble. If not, method 810 proceeds, at step 811, to apply a heat treatment to decompose the electrode material, at step 812, to separate the electrode material from other battery waste, and at step 813, to apply the electrode material to the battery manufacturing process. If the binder is water-soluble, method 810 proceeds, at step 861, to wash the battery waste and the electrode material, at step 862, to separate the electrode material from other battery waste, and at step 863, to filter and dry the electrode material.

[0125] Step 801 includes determining whether the battery waste or a subset of the battery waste is water-soluble. In some embodiments, the battery waste or a subset thereof can undergo an elution test in water to determine the presence of a water-soluble or water-insoluble binder. In some embodiments, the type of binder is known in advance. In some embodiments, the battery waste is tested using an assay, spectroscopy, spectral analysis, or other similar tests to determine the presence of a water-soluble or water-insoluble binder. In some embodiments, this test can be gas chromatography, mass spectrometry, Raman spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, or other similar tests, or a combination thereof.

[0126] When the binder is water-soluble, step 861 includes the step of washing the battery waste containing the electrode material. In some embodiments, the washing can be by an aqueous solvent (e.g., water). In some embodiments, step 861 can have any of the processing parameters of step 611 as described above with reference to FIG. 7. Step 862 includes the step of separating the electrode material from other battery waste. In some embodiments, step 862 can include any of the processing parameters of step 713 as described above with reference to FIG. 8. Step 863 includes the step of filtering and drying the electrode material. In some embodiments, step 863 can include any of the processing parameters of step 715 as described above with reference to FIG. 8. The steps of filtering and drying can result in an electrode material such as a graphite electrode material. In some embodiments, the electrode material can further undergo a surface treatment operation to modify the surface of the electrode material. In some embodiments, the surface treatment operation can have any of the characteristics of step 714 as described above with reference to FIG. 8. In some embodiments, the electrode material can further undergo a heat treatment operation to regenerate the electrode material. In some embodiments, the heat treatment operation can have any of the characteristics of the first heat treatment operation in step 13 and / or the second heat treatment operation in step 18 as described above with reference to FIG. 1.

[0127] In the case of battery waste containing a water-insoluble binder, method 810 includes, in step 811, applying a heat treatment to decompose the electrode material. The heat treatment can partially or completely remove or disintegrate the water-insoluble binder (e.g., PVDF). In some embodiments, the battery waste is heat-treated to a temperature of at least about 400°C, at least about 450°C, at least about 500°C, or at least about 550°C. In some embodiments, the battery waste is heat-treated at a temperature of about 600°C or less, about 550°C or less, about 500°C or less, or about 400°C or less. The above-mentioned combinations of temperatures for heat-treating the battery waste are also possible (e.g., at least about 400°C and about 600°C or less, or at least about 450°C and about 550°C or less) (including all values and ranges therebetween). In some embodiments, the battery waste is heat-treated at a temperature of about 400°C, about 450°C, about 500°C, about 550°C, or about 600°C. In some embodiments, the heat treatment is performed under an inert gas as described above. In some embodiments, the waste gas generated during the heat treatment is scrubbed, washed, cleaned, and / or filtered to remove any hazardous or undesirable compounds (e.g., hydrogen fluoride).

[0128] Step 812 includes separating the electrode material from other battery waste. In some embodiments, the separation operation uses dry methods such as rotary screening, vibration and ultrasonic screening, and air jet screening to separate the current collector or other battery waste components (which can include additives that may still be present in the electrode powder) from the electrode powder. Step 812 can include separating the electrode material from the current collector. In some embodiments, the current collector can include a copper sheet, and the electrode material can include graphite. As a product in this recycling process, the separated electrode material is collected (e.g., in powder form). In some embodiments, the separation of the electrode material from other battery waste can have any of the processing parameters of step 713 as described above with reference to FIG. 8.

[0129] In some embodiments, the electrode material can further undergo a surface treatment operation to modify the surface of the electrode material. In some embodiments, the electrode material can further undergo a heat treatment operation to regenerate the electrode material. These surface treatment and / or heat treatment processes can include any of the processing parameters of the surface treatment process and / or heat treatment process described above.

[0130] FIG. 10 is a flowchart of a method 910 for recycling battery waste according to one embodiment. In some embodiments, method 910 can be used in a system or facility. In some embodiments, method 910 can be used to recycle a Li x M y PO4 electrode material, where M is at least one transition metal, and x and y are integers. In some embodiments, method 910 can be used to recycle LFMP or other similar LFP or LFMP compounds and / or their derivatives. In some embodiments, the battery waste can include a cathode material (with or without a binder) on a current collector. In some embodiments, the battery waste can include other battery components such as a package or a separator. In some embodiments, the battery waste can include an anode. In some embodiments, the battery waste can include an electrolyte and / or a lithium salt. In some embodiments, the battery waste can include a cathode additive such as conductive carbon.

[0131] As shown, method 910 includes, in step 911, applying a first heat treatment to at least partially disintegrate battery waste, in step 912, separating electrode materials from other battery waste, and in step 913, optionally applying a second heat treatment to at least partially remove electrode additives from the electrode materials. Method 910 includes, in step 914, optionally mixing and milling the electrode materials. Method 910 further includes, in step 915, applying a third heat treatment in a reducing environment. Method 910 optionally includes, in step 916, mixing and milling the electrode materials, and in step 917, applying a fourth heat treatment. Method 910 further includes, in step 918, reducing the size of the electrode materials.

[0132] In step 911, method 910 includes applying a first heat treatment to at least partially disintegrate the battery waste. The first heat treatment can partially or completely remove or downgrade battery waste components such as binders, electrolytes, and lithium salts. The temperature of the first heat treatment can decompose and / or disintegrate at least a portion of the battery waste components. Next, the decomposed and / or disintegrated portions of the battery waste components can be removed (e.g., by vaporization). In some embodiments, the first heat treatment can be performed in an inert gas environment. In some embodiments, the first heat treatment can be performed in a reducing gas environment. In some embodiments, the gas environment can include gases such as CO2, CO, N2, Ar, H2, or mixtures thereof. In some embodiments, the first heat treatment can be performed in an oxidizing gas environment. In some embodiments, the first heat treatment can be performed in air. In some embodiments, the first heat treatment can be performed in a high oxygen environment (e.g., at least about 20 vol%, at least about 25 vol%, at least about 30 vol%, at least about 35 vol%, at least about 40 vol%, at least about 45 vol%, at least about 50 vol%, at least about 55 vol%, at least about 60 vol%, at least about 65 vol%, at least about 70 vol%, at least about 75 vol%, at least about 80 vol%, at least about 85 vol%, at least about 90 vol%, or at least about 95 vol% oxygen, including all values and ranges therebetween). In some embodiments, the first heat treatment can be performed in a pure oxygen environment. In some embodiments, the first heat treatment can be performed in an environment containing at least about 96 vol%, at least about 97 vol%, at least about 98 vol%, at least about 99 vol%, at least about 99 vol%, at least about 99.9 vol%, at least about 99.99 vol%, or at least about 99.999 vol% oxygen.

[0133] In some embodiments, the first heat treatment can be at a temperature of at least about 300°C, at least about 350°C, at least about 400°C, at least about 450°C, at least about 500°C or at least about 550°C, at least about 600°C, at least about 650°C, at least about 700°C, at least about 750°C, at least about 800°C, at least about 850°C, at least about 900°C, at least about 950°C, at least about 1,000°C, at least about 1,050°C or at least about 1,100°C. In some embodiments, the first heat treatment can be at a temperature of about 1,150°C or less, about 1,100°C or less, about 1,050°C or less, about 1,000°C or less, about 950°C or less, about 900°C or less, about 850°C or less, about 800°C or less, about 750°C or less, about 700°C or less, about 650°C or less, about 600°C or less, about 550°C or less, about 500°C or less, about 450°C or less, about 400°C or less or about 350°C or less. Combinations of the temperatures mentioned above are also possible (e.g., at least about 300°C and about 1,150°C or less, or at least about 500°C and about 800°C or less) (including all values and ranges therebetween). In some embodiments, the first heat treatment can be at a temperature of about 300°C, about 350°C, about 400°C, about 450°C, about 500°C, about 550°C, about 600°C, about 650°C, about 700°C, about 750°C, about 800°C, about 850°C, about 900°C, about 950°C, about 1,000°C, about 1,050°C, about 1,100°C or about 1,150°C.

[0134] In some embodiments, the first heat treatment can have a duration of at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours, at least about 11 hours, at least about 12 hours, at least about 13 hours, at least about 14 hours or at least about 15 hours. In some embodiments, the first heat treatment can have a duration of about 16 hours or less, about 15 hours or less, about 14 hours or less, about 13 hours or less, about 12 hours or less, about 11 hours or less, about 10 hours or less, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less or about 2 hours or less. Combinations of the above-recited durations of the first heat treatment are also possible (e.g., at least about 1 hour and about 16 hours or less, or at least about 4 hours and about 8 hours or less) (including all values and ranges therebetween). In some embodiments, the first heat treatment can have a duration of about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15 hours or about 16 hours.

[0135] Step 912 includes separating the electrode material from other battery waste components. In some embodiments, the other battery waste components can include a current collector and / or a separator. In some embodiments, the electrode material can include electrode powder. In some embodiments, the separation can be by a dry separation method. In some embodiments, the separation can be by rotary screening, vibration, ultrasonic screening, air jet screening, or any combination thereof. In some embodiments, the separation can include a wet separation method. In some embodiments, the separation can include agitation washing, ultrasonic treatment, or any combination thereof.

[0136] Step 913 is optional and includes a second heat treatment to remove at least a portion of the electrode additive from the electrode material. In some embodiments, the second heat treatment may be configured in an oxidizing gas environment to decompose and / or disintegrate battery waste components such as binders, electrolytes, lithium salts, anodes, and / or electrode additives. In some embodiments, the second heat treatment may be performed in air. In some embodiments, the second heat treatment may be performed in a high oxygen environment (e.g., at least about 20 vol%, at least about 25 vol%, at least about 30 vol%, at least about 35 vol%, at least about 40 vol%, at least about 45 vol%, at least about 50 vol%, at least about 55 vol%, at least about 60 vol%, at least about 65 vol%, at least about 70 vol%, at least about 75 vol%, at least about 80 vol%, at least about 85 vol%, at least about 90 vol% or at least about 95 vol% oxygen, including all values and ranges therebetween). In some embodiments, the second heat treatment may be performed in a pure oxygen environment. In some embodiments, the second heat treatment may be performed in an environment containing at least about 96 vol%, at least about 97 vol%, at least about 98 vol%, at least about 99 vol%, at least about 99 vol%, at least about 99.9 vol%, at least about 99.99 vol% or at least about 99.999 vol% oxygen.

[0137] In some embodiments, by the second heat treatment, additives can be partially or completely removed from the electrodes, including conductive carbon. In some embodiments, by the second heat treatment, the graphite of the anode can be partially or completely removed from the electrode material. In some embodiments, the conductive carbon and / or graphite in the battery waste can be partially or entirely oxidized during the second heat treatment to generate CO or CO2. In some embodiments, the electrode material can be partially or entirely oxidized after the second heat treatment. In some embodiments, the LFP electrode material can be partially or entirely oxidized during the second heat treatment to produce an oxidized cathode product. In some embodiments, the oxidized cathode product can include Fe2O3, Fe3O4, Li3Fe2(PO4)3, LiFeP2O7FePO4, Li3PO4, Li2CO3, LiOH, or any combination thereof.

[0138] In some embodiments, the second heat treatment can be at a temperature of at least about 300°C, at least about 350°C, at least about 400°C, at least about 450°C, at least about 500°C or at least about 550°C, at least about 600°C, at least about 650°C, at least about 700°C, at least about 750°C, at least about 800°C, at least about 850°C, at least about 900°C, at least about 950°C, at least about 1,000°C, at least about 1,050°C or at least about 1,100°C. In some embodiments, the second heat treatment can be at a temperature of about 1,150°C or less, about 1,100°C or less, about 1,050°C or less, about 1,000°C or less, about 950°C or less, about 900°C or less, about 850°C or less, about 800°C or less, about 750°C or less, about 700°C or less, about 650°C or less, about 600°C or less, about 550°C or less, about 500°C or less, about 450°C or less, about 400°C or less or about 350°C or less. Combinations of the temperatures mentioned above are also possible (e.g., at least about 300°C and about 1,150°C or less, or at least about 500°C and about 800°C or less) (including all values and ranges therebetween). In some embodiments, the second heat treatment can be at a temperature of about 300°C, about 350°C, about 400°C, about 450°C, about 500°C, about 550°C, about 600°C, about 650°C, about 700°C, about 750°C, about 800°C, about 850°C, about 900°C, about 950°C, about 1,000°C, about 1,050°C, about 1,100°C or about 1,150°C.

[0139] In some embodiments, the second heat treatment can have a duration of at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours, at least about 11 hours, at least about 12 hours, at least about 13 hours, at least about 14 hours or at least about 15 hours. In some embodiments, the second heat treatment can have a duration of about 16 hours or less, about 15 hours or less, about 14 hours or less, about 13 hours or less, about 12 hours or less, about 11 hours or less, about 10 hours or less, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less or about 2 hours or less. Combinations of the durations mentioned above for the first heat treatment are also possible (e.g., at least about 1 hour and about 16 hours or less, or at least about 4 hours and about 8 hours or less) (including all values and ranges therebetween). In some embodiments, the second heat treatment can have a duration of about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15 hours or about 16 hours.

[0140] In some embodiments, the second heat treatment can oxidize some or all of any additional materials or impurities in the battery waste. In some embodiments, the aluminum in the battery waste can be partially or fully oxidized. In some embodiments, the copper in the battery waste can be partially or fully oxidized. In some embodiments, the iron in the battery waste can be partially or fully oxidized. In some embodiments, the oxidation of impurities such as Al, Cu or Fe can improve the performance of the finally recovered cathode product, reduce or eliminate the short-circuiting of any conductive impurities or other ways of causing damage to the battery, and / or facilitate further removal of the impurities.

[0141] In some embodiments, the first heat treatment of step 911 and the second heat treatment of step 913 can be combined into a single heat treatment before the separation in step 912. By this single heat treatment, some battery waste components such as the binder, electrolyte, lithium salt, anode material and / or conductive carbon can be partially or completely decomposed and / or disintegrated. In some embodiments, the first heat treatment of step 911 and / or the second heat treatment of step 913 can partially or completely oxidize the cathode material.

[0142] In some embodiments, the waste gas generated during the first heat treatment and / or the second heat treatment is scrubbed, cleaned and / or filtered as shown in FIG. 1 to remove any dangerous or undesirable compounds (e.g., hydrogen fluoride, hydrofluorocarbon, fluorocarbon and / or volatile organic compound (VOC)) so that a cleaner gas can be exhausted as described above in steps 14 and 18.

[0143] In some embodiments, the electrode material can undergo further reduction and regeneration to produce a commercially usable recovered material. In some embodiments, the oxidized cathode product can undergo further reduction and regeneration to form a commercially usable recovered material. In step 914, the electrode material is optionally subjected to a mixing process and a milling process. In some embodiments, additives such as a lithium source (e.g., Li2CO3, LiOH) and / or a reducing agent (e.g., carbon, or an organic compound such as glucose, graphite or starch) can be added during step 914 to facilitate mixing and milling. In some embodiments, the addition of glucose, graphite or starch during the heat treatment can be used to partially or completely decompose the glucose, graphite or starch to form a carbon coating on the cathode, which can result in an improvement in the electrochemical performance. In some embodiments, the mixing and milling can be performed by wet mixing using an apparatus such as a nanobead mill, a planetary ball mill, a roller jar mill or any combination thereof.

[0144] In some embodiments, the size and geometry of the electrode material can be controlled during the mixing and milling of step 914. In some embodiments, the milling media can have a size of at least about 0.01 mm, at least about 0.05 mm, at least about 0.1 mm, at least about 0.5 mm, at least about 1 mm, at least about 5 mm, at least about 10 mm, or at least about 50 mm. In some embodiments, the milling media can have a size of about 100 mm or less, about 50 mm or less, about 10 mm or less, about 5 mm or less, about 1 mm or less, about 0.5 mm or less, about 0.1 mm or less, or about 0.05 mm or less. Combinations of the sizes of the milling media mentioned above are also possible (e.g., at least about 0.01 mm and about 100 mm or less, or at least about 0.01 mm and about 0.1 mm or less, or at least about 0.1 mm and about 1 mm or less, or at least about 1 mm and about 10 mm or less, or at least about 10 mm and about 100 mm or less) (including all values and ranges therebetween). In some embodiments, the milling media can have a size of about 0.01 mm, about 0.05 mm, about 0.1 mm, about 0.5 mm, about 1 mm, about 5 mm, about 10 mm, about 50 mm, or about 100 mm.

[0145] In some embodiments, the grinding and mixing in step 914 can be for a duration of at least about 30 seconds, at least about 36 seconds, at least about 1 minute, at least about 6 minutes, at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 9 hours, at least about 10 hours, at least about 20 hours, at least about 30 hours, at least about 40 hours, at least about 50 hours, at least about 60 hours, at least about 70 hours, at least about 80 hours or at least about 90 hours. In some embodiments, the grinding and mixing in step 914 can be for a duration of about 100 hours or less, about 90 hours or less, about 80 hours or less, about 70 hours or less, about 60 hours or less, about 50 hours or less, about 40 hours or less, about 30 hours or less, about 20 hours or less, about 10 hours or less, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less, about 2 hours or less, about 1 hour or less, about 30 minutes or less, about 6 minutes or less or about 36 seconds or less. Combinations of the durations mentioned above are also possible (e.g., at least about 30 seconds and about 100 hours or less, or at least about 5 hours and about 50 hours or less) (including all values and ranges therebetween). In some embodiments, the grinding and mixing in step 914 can be for a duration of about 30 seconds, about 36 seconds, about 1 minute, about 6 minutes, about 30 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 9 hours, about 10 hours, about 20 hours, about 30 hours, about 40 hours, about 50 hours, about 60 hours, about 70 hours, about 80 hours, about 90 hours or about 100 hours.

[0146] In some embodiments, the rotational speed for the mixing and milling process in step 914 can be at least about 0 rpm, at least about 1 rpm, at least about 5 rpm, at least about 10 rpm, at least about 100 rpm, at least about 500 rpm, at least about 1,000 rpm, at least about 2,000 rpm, at least about 5,000 rpm, at least about 10,000 rpm, or at least about 20,000 rpm. In some embodiments, the rotational speed for the mixing and milling process in step 914 can be about 50,000 rpm or less, about 20,000 rpm or less, about 10,000 rpm or less, about 5,000 rpm or less, about 2,000 rpm or less, about 1,000 rpm or less, about 5,000 rpm or less, about 1,000 rpm or less, about 500 rpm or less, about 100 rpm or less, about 10 rpm or less, about 5 rpm or less, or about 1 rpm or less. Combinations of the rotational speeds mentioned above are also possible (e.g., at least about 0 rpm and about 50,000 rpm or less, or at least about 100 rpm and about 10,000 rpm or less) (including all values and ranges therebetween). In some embodiments, the rotational speed for the mixing and milling process in step 914 can be about 0 rpm, about 1 rpm, about 5 rpm, about 10 rpm, about 100 rpm, about 500 rpm, about 1,000 rpm, about 2,000 rpm, about 5,000 rpm, about 10,000 rpm, or about 20,000 rpm. In some embodiments, the rotational speed for the mixing and milling process can be about 0 rpm to about 100 rpm, about 100 rpm to about 500 rpm, about 500 rpm to about 1,000 rpm, about 1,000 rpm to about 2,000 rpm, about 2,000 rpm to about 5,000 rpm, about 5,000 rpm to about 10,000 rpm, about 10,000 rpm to about 20,000 rpm, and about 20,000 rpm to 50,000 rpm.

[0147] In some embodiments, dispensing materials such as water, ethanol, or other organic solvents can be added to improve the mixing performance. In some embodiments, the drying process after wet mixing can be performed using devices such as spray dryers, stirring dryers, conical dryers, vacuum rotary dryers, drum scraper dryers, flash dryers, or any combination thereof. In some embodiments, the geometry and particle size of the electrode material can be controlled by adjusting the feed rate and / or drying temperature during the mixing process. In some embodiments, the geometry and particle size of the electrode material can be controlled by adjusting the feed rate and / or drying temperature after the mixing process. In some embodiments, the mixing and milling in step 914 can be performed by dry mixing using devices such as air jet mills, high-speed mixers, ball mills, or any combination thereof.

[0148] Step 915 includes applying a third heat treatment to the electrode material in a reducing environment. In some embodiments, the third heat treatment can form olivine FePO4 (or other derivatives such as MPO4, where M is at least one transition metal) and a lithium salt. In some embodiments, a predetermined amount of lithium source can be mixed with the electrode material (e.g., the oxidized cathode product) during the third heat treatment if the electrode material is lithium-deficient. In some embodiments, the third heat treatment can be performed in an inert environment. In some embodiments, the third heat treatment can be performed in an inert environment or a reducing gas environment to reduce the oxidized cathode product. In some embodiments, the reducing agent added may be equal to or exceed the stoichiometric amount for completely reducing the electrode material. In some embodiments, the reducing agent can include glucose. In some embodiments, the third heat treatment can completely reduce iron to form a reduced iron compound.

[0149] In some embodiments, the third heat treatment can be at a temperature of at least about 300 °C, at least about 350 °C, at least about 400 °C, at least about 450 °C, at least about 500 °C or at least about 550 °C, at least about 600 °C, at least about 650 °C, at least about 700 °C, at least about 750 °C, at least about 800 °C, at least about 850 °C, at least about 900 °C, at least about 950 °C, at least about 1,000 °C, at least about 1,050 °C or at least about 1,100 °C. In some embodiments, the third heat treatment can be at a temperature of about 1,150 °C or less, about 1,100 °C or less, about 1,050 °C or less, about 1,000 °C or less, about 950 °C or less, about 900 °C or less, about 850 °C or less, about 800 °C or less, about 750 °C or less, about 700 °C or less, about 650 °C or less, about 600 °C or less, about 550 °C or less, about 500 °C or less, about 450 °C or less, about 400 °C or less or about 350 °C or less. Combinations of the temperatures recited above are also possible (e.g., at least about 300 °C and about 1,150 °C or less, or at least about 500 °C and about 800 °C or less) (including all values and ranges therebetween). In some embodiments, the third heat treatment can be at a temperature of about 300 °C, about 350 °C, about 400 °C, about 450 °C, about 500 °C, about 550 °C, about 600 °C, about 650 °C, about 700 °C, about 750 °C, about 800 °C, about 850 °C, about 900 °C, about 950 °C, about 1,000 °C, about 1,050 °C, about 1,100 °C or about 1,150 °C.

[0150] In some embodiments, the third heat treatment can have a duration of at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours, at least about 11 hours, at least about 12 hours, at least about 13 hours, at least about 14 hours, or at least about 15 hours. In some embodiments, the third heat treatment can have a duration of about 16 hours or less, about 15 hours or less, about 14 hours or less, about 13 hours or less, about 12 hours or less, about 11 hours or less, about 10 hours or less, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less, or about 2 hours or less. Combinations of the above-recited durations of the first heat treatment are also possible (e.g., at least about 1 hour and about 16 hours or less, or at least about 4 hours and about 8 hours or less) (including all values and ranges therebetween). In some embodiments, the third heat treatment can have a duration of about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15 hours, or about 16 hours.

[0151] Step 916 is optional and includes the step of mixing and milling the electrode material. In some embodiments, step 916 can include any of the processing parameters of step 914 as described above. Thus, certain aspects of step 916 are not described in further detail herein.

[0152] Step 917 is optional and includes a fourth heat treatment. In some embodiments, the fourth heat treatment can fully reduce iron (or other corresponding elements in MPO4) to form olivine LiFePO4 (or other LFP derivatives such as LFMP). In some embodiments, the fourth heat treatment can have any of the same parameters as the third heat treatment as described above with reference to step 915. In some embodiments, the fourth heat treatment is performed in an inert environment or a reducing gas environment to reduce the oxidized cathode product. In some embodiments, the fourth heat treatment can form olivine LiFePO4 (or other derivatives such as LFMP). In some embodiments, the fourth heat treatment can be performed in an inert environment or a reducing environment. In some embodiments, the third heat treatment of step 915 and the fourth heat treatment of step 917 can be combined into a single heat treatment step.

[0153] In some embodiments, the fourth heat treatment can be at a temperature of at least about 300°C, at least about 350°C, at least about 400°C, at least about 450°C, at least about 500°C or at least about 550°C, at least about 600°C, at least about 650°C, at least about 700°C, at least about 750°C, at least about 800°C, at least about 850°C, at least about 900°C, at least about 950°C, at least about 1,000°C, at least about 1,050°C or at least about 1,100°C. In some embodiments, the fourth heat treatment can be at a temperature of about 1,150°C or less, about 1,100°C or less, about 1,050°C or less, about 1,000°C or less, about 950°C or less, about 900°C or less, about 850°C or less, about 800°C or less, about 750°C or less, about 700°C or less, about 650°C or less, about 600°C or less, about 550°C or less, about 500°C or less, about 450°C or less, about 400°C or less or about 350°C or less. Combinations of the temperatures mentioned above are also possible (e.g., at least about 300°C and about 1,150°C or less, or at least about 500°C and about 800°C or less) (including all values and ranges therebetween). In some embodiments, the fourth heat treatment can be at a temperature of about 300°C, about 350°C, about 400°C, about 450°C, about 500°C, about 550°C, about 600°C, about 650°C, about 700°C, about 750°C, about 800°C, about 850°C, about 900°C, about 950°C, about 1,000°C, about 1,050°C, about 1,100°C or about 1,150°C.

[0154] In some embodiments, the fourth heat treatment can have a duration of at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours, at least about 11 hours, at least about 12 hours, at least about 13 hours, at least about 14 hours or at least about 15 hours. In some embodiments, the fourth heat treatment can have a duration of about 16 hours or less, about 15 hours or less, about 14 hours or less, about 13 hours or less, about 12 hours or less, about 11 hours or less, about 10 hours or less, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less or about 2 hours or less. The combinations of durations mentioned above for the first heat treatment are also possible (e.g., at least about 1 hour and about 16 hours or less, or at least about 4 hours and about 8 hours or less) (including all values and ranges therebetween). In some embodiments, the fourth heat treatment can have a duration of about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15 hours or about 16 hours.

[0155] Step 18 includes a step of reducing the size of the electrode material. In some embodiments, the process of reducing the size can include milling or ball milling. In some embodiments, the process of reducing the size can reduce the size of the particles of the electrode material (e.g., LFP cathode material) to a D50 value of less than about 100 μm, less than about 75 μm, less than about 50 μm, less than about 25 μm, less than about 10 μm, less than about 5 μm, less than about 2 μm, less than about 1 μm, less than about 0.5 μm, less than about 0.2 μm, or less than about 0.1 μm. In some embodiments, the process of reducing the size can be performed by an air jet mill.

[0156] In some embodiments, the methods described herein can include other processes described herein. In some embodiments, the methods described herein can include separation, purification, filtration, drying, washing, and surface treatment processes described herein. In some embodiments, the methods described herein can include at least one of a purification step (as described above), a filtration step (as described above), a drying step (as described above), and / or a surface treatment step (as described above) after separation (e.g., step 15). In some embodiments, the methods described herein can include at least one of a purification step (as described above), a filtration step (as described above), a drying step (as described above), and / or a surface treatment step (as described above) after a first heat treatment (e.g., step 13) and / or a second heat treatment (e.g., step 18). In some embodiments, the methods described herein can include at least one of a purification step (as described above), a filtration step (as described above), a drying step (as described above), and / or a surface treatment step (as described above) after mixing / milling (e.g., step 717).

Examples

[0157] Example 1 The electrochemical performance of various electrode materials recycled from scrap of waste electrodes (LTO anodes, NCM cathodes, and LFP cathodes) is compared with that of virgin electrode materials (standards). The electrochemical performance is measured in a CR-2032 type coin cell composed of a lithium metal electrode, a polypropylene separator, an electrode made from recycled material or standard material, and an electrolyte of 1 M LiPF6 in EC / DMC (3:7 by volume). The recycled electrode or standard electrode was prepared by mixing 80 weight percent (wt%) of the recycled powder with 10 wt% of PVDF and 10 wt% of conductive carbon. This coin cell was charged and discharged at a 1C rate (n-C rate means a charge / discharge process that ends in 1 / n hours). Figure 11 shows the cycle performance of the recycled LTO material compared to that of the standard LTO material. The LTO material was recycled from waste LTO scrap by an embodiment of the direct recycling process similar to that in Figure 8. In the case of the recycled LTO material, no obvious capacity decay was observed over 150 cycles, while the standard LTO material showed a capacity decay of about 12%.

[0158] Example 2 Figure 12 shows the cycle performance of the recycled NCM material compared to that of the standard NCM material. The NCM material was recycled from waste NCM scrap by an embodiment of the direct recycling process similar to that in Figure 9. The NCM material was treated with 5 vol% acetic acid for 20 minutes at room temperature. The solid loading was set at 10 g / 100 ml. Compared with the standard NCM material, the recycled NCM without surface treatment showed a slightly lower initial discharge capacity but a slower capacity decay rate. The recycled NCM material with surface treatment showed a similar initial discharge capacity and better capacity retention.

[0159] Example 3 Figure 13 shows the cycle performance of the recycled LFP material compared to that of the standard LFP material. The LFP material was recycled from waste LFP scrap by an embodiment of the direct recycling process similar to that shown in Figure 9. Overall, the recycled LFP material shows very similar cycle performance compared to the standard LFP material.

[0160] Example 4 The LFP cathode waste scrap material was treated by a first heat treatment under an air flow rate of between 5 and 50 standard cubic feet per hour (SCFH). The first heat treatment was carried out at 300 °C to 500 °C for 1 hour. The cathode electrode powder became detached from the current collector because the binder decomposed. The LFP electrode powder was separated from the Al current collector. The LFP powder was passed through a second heat treatment under an air flow rate of between 5 and 50 SCFH. The second heat treatment was carried out at 400 °C to 700 °C for 1 hour. The electrode powder turned red after the second heat treatment, suggesting that an oxidized cathode product was formed. Figure 14 shows that the XRD pattern of the electrode powder after the second heat treatment changed significantly compared to that of the standard LFP powder. After the second heat treatment, the phases of Li3Fe2(PO4)3, LiFeP2O7 and Fe2O3 appeared, indicating that the electrode material was oxidized. Also, the carbon content in the electrode material decreased from 0.03 wt% to 0.1 wt% (compared to 2 - 3 wt% without the second heat treatment). Next, 0.62 g of glucose and 0.06 g of LiOH·H2O were mixed with 4.5 g of the electrode powder collected after the second heat treatment. The mixing process was carried out in a planetary ball mill with the addition of 18 ml of water. A uniform powder mixture was collected after drying. Next, the electrode powder was passed through a third heat treatment to complete the regeneration process. The third heat treatment was carried out at 600 °C to 700 °C for 3 hours under a nitrogen flow.

[0161] The electrochemical performance of the recycled LFP material was measured in a CR-2032 type coin cell composed of a lithium metal counter electrode, a polypropylene separator, and an electrolyte of 1 M LiPF6 in EC / DMC (3:7 by volume). The working electrode was prepared by mixing 80 weight percent (wt%) of the recycled powder with 10 wt% of PVDF and 10 wt% of conductive carbon. This coin cell was charged and discharged at a 1C rate. Figure 15 shows that the recycled LFP material provided a capacity at a 1C rate, compared to the standard LFP cathode material.

[0162] Various concepts may be embodied in one or more ways, and at least one example of each is presented. Operations performed as part of the present methods may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in a different order than illustrated, including performing some acts simultaneously, even if shown as sequential acts in the illustrative embodiments. In other words, such features may not necessarily be limited to a particular order of execution, but rather may be performed continuously, asynchronously, all at once, in parallel, simultaneously, synchronously, and / or similarly, in any number of threads, processes, services, servers, and / or the like, in a manner consistent with the present disclosure. Accordingly, some of these features may be mutually contradictory in that they cannot simultaneously exist in a single embodiment. Similarly, some features may be applicable to one aspect of the technological innovation and not applicable to other aspects.

[0163] Furthermore, the present disclosure may include other technological innovations that are not currently described. The applicant has all rights in such technological innovations, including the rights to embody, file additional applications, continue, partially continue, divide, and / or the like thereof. Therefore, it should be understood that the advantages, embodiments, examples, functions, features, logic, operations, organizational, structural, topological, and / or other aspects of the present disclosure should not be considered as limitations to the present disclosure defined by the embodiments or limitations equivalent to the embodiments. Depending on the specific requirements and / or characteristics of individual and / or corporate users, database configurations, and / or relationship models, data types, data transfers, and / or network frameworks, syntax structures, and / or the like, various embodiments of the technologies disclosed herein may be implemented in a manner that allows for great flexibility and customization as described herein.

[0164] It should be understood that all definitions defined and used herein shall prevail over dictionary definitions, definitions in incorporated documents by reference, and / or the ordinary meaning of the defined terms.

[0165] As used herein, in a particular embodiment, the terms "about" or "approximately," when preceding a numerical value, indicate a range of plus or minus 10% of that value. When a range of values is presented, each intervening value between the upper and lower limits of that range, as well as any other specified value or intervening value within the specified range, is understood to be included within the present disclosure to the extent of one-tenth of the unit of the lower limit, unless specifically indicated otherwise by the context. The upper and lower limits of these smaller ranges may also be independently included within the smaller ranges, and are also included within the present disclosure in accordance with any specifically excluded boundary values within the specified range. When the specified range includes one or both of the boundary values, ranges excluding either one or both of the included boundary values are also included in the present disclosure.

[0166] In this specification and embodiments, the phrase "and / or" as used herein should be understood to mean "either or both" of the elements so connected, i.e., elements that in some cases coexist conjunctively and in other cases exist disjunctively. Multiple elements listed by "and / or" should likewise be construed as "one or more" of the elements so connected. Other elements other than those specifically identified by the clause of "and / or" may exist as necessary, whether or not they are related to the specifically identified elements. Thus, by way of non-limiting example, a reference to "A and / or B", when used in conjunction with an open-ended phrase such as "comprising", in one embodiment, only A (optionally including elements other than B), in another embodiment, only B (optionally including elements other than A), and in yet another embodiment, both A and B (optionally including other elements), etc. can be referred to.

[0167] "Or" should be understood to have the same meaning as "and / or" as defined above when used herein in this specification and embodiments. For example, when separating items in a list, "or" or "and / or" should be construed as inclusive, i.e., including at least one of several elements or a list of elements, but also including more than one and optionally additional unlisted items. Only terms such as "only one of" or "exactly one of", or when used in embodiments, terms such as "consisting of" that are clearly indicated to the contrary, refer to including exactly one element of several elements or a list of elements. Generally, the term "or", when used in this specification, should be construed to indicate an exclusive alternative (i.e., "one or the other, but not both") only when preceded by an exclusive term such as "either", "only one of", "only one of only" or "exactly one of". "Consisting essentially of", when used in embodiments, shall have its ordinary meaning as used in the field of patent law.

[0168] In this specification and the embodiments, as used herein, the phrase "at least one" referring to a list of one or more elements means at least one element selected from any one or more of the elements in the list of elements, but does not necessarily include at least one of every element specifically listed in the list of elements, and is not to be construed as excluding any combination of elements in the list of elements. This definition also allows that elements other than those specifically identified in the list of elements referred to by the phrase "at least one" may optionally exist, whether or not they are related to such specifically identified elements. Thus, by way of non-limiting example, "at least one of A and B" (or equivalently "at least one of A or B", or equivalently "at least one of A and / or B") can, in one embodiment, refer to at least one A, optionally including more than one A, and no B (and optionally including elements other than B); in another embodiment, refer to at least one B, optionally including more than one B, and no A (and optionally including elements other than A); and in yet another embodiment, refer to at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other elements).

[0169] In the embodiments and the above specification, it should be understood that all transitional phrases such as "comprising", "including", "carrying", "having", "containing", "involving", "holding", "composed of", etc. are open-ended, that is, they are meant to include but not be limited to ~. As explained in item 2111.03 of the Patent Examination Procedure Manual of the United States Patent and Trademark Office, only the transitional phrases "consisting of" and "consisting essentially of" are to be closed transitional phrases or semi-closed transitional phrases, respectively.

[0170] Although specific embodiments of the present disclosure have been outlined above, numerous alternative, modified, and variant forms will be apparent to those skilled in the art. Accordingly, the embodiments described herein are intended to be illustrative rather than limiting. Various changes can be made without departing from the spirit and scope of the present disclosure. Where the methods and steps described above indicate that a particular event occurs in a particular order, those skilled in the art who benefit from the present disclosure will recognize that the ordering of the particular steps may be modified and that such modifications are in accordance with variants of the invention. Further, certain steps may, where possible, be performed simultaneously in a parallel process or, as described above, sequentially. It is understood that, although embodiments have been particularly shown and described, various changes in form and detail may be made.

Claims

1. A method for recycling a certain amount of battery waste, wherein the battery waste includes an electrode material and a current collector, the electrode material includes an active material and a binder, and the method comprises: Applying a first heat treatment to the battery waste at a temperature between about 100°C and about 700°C, wherein the first heat treatment decomposes at least about 80% by weight of the binder; Separating the electrode material from the current collector; and Applying a second heat treatment to the electrode material at a temperature between about 400°C and about 1,200°C to produce a recycled electrode material, wherein the second heat treatment decomposes at least 90% by weight of the binder remaining in the electrode material to produce a recycled electrode material. A method comprising the above steps.

2. The method according to claim 1, further comprising applying a surface treatment to the electrode material to remove a surface coating agent and / or surface impurities from the electrode material.

3. The method according to claim 2, wherein the surface treatment includes applying a solvent to the electrode material.

4. The method according to claim 3, wherein the solvent includes at least one of citric acid, acetic acid, oxalic acid, ammonia, ammonium hydroxide, ammonium chloride, or their chemical derivatives.

5. The electrode material includes at least one of LiCoO ２ , LiMn ２ O ４ , LiFe ｔ M １－ｔ PO ４ or LiNi ａ Mn ｂ Co ｃ A ｄ O ２ where a + b + c + d = 1, 0 < t < 1, A is Al, Zr, or Mg, The method according to claim 1.

6. The first heat treatment has a duration between about 1 hour and about 6 hours at a temperature between about 400 °C and about 600 °C, The second heat treatment has a duration between about 1 hour and about 5 hours and a temperature between about 450 °C and about 800 °C, The method according to claim 1.

7. The first heat treatment has a duration between about 1 hour and about 6 hours at a temperature between about 400 °C and about 600 °C, The second heat treatment has a duration between about 3 hours and about 15 hours and a temperature between about 600 °C and about 900 °C, The method according to claim 1.

8. The method according to claim 1, wherein the recycled electrode material has a lithium concentration of at least about 99 wt%.

9. The step of washing the electrode material to remove at least a part of the binder The method according to claim 1, further comprising.

10. Before the first heat treatment, the step of removing oxidizable impurities from the electrode material by treatment with at least one of an acid having a pH of about 4 or less or a base having a pH of at least about 13 The method according to claim 1, further comprising.

11. The method according to claim 1, wherein the second heat treatment vaporizes all of the binder remaining in the electrode material.

12. A method for recycling a certain amount of battery waste, wherein the battery waste includes an electrode material connected to a current collector, the electrode material includes an active material and a binder, and the method includes A step of washing the battery waste with a solvent, as a result of which the solvent dissolves a part of the binder, and at least a part of the electrode material is separated from the current collector A step of vaporizing at least about 80% by weight of the binder by a first heat treatment A step of flotation of the electrode material in a polar solvent mixed with an enhancer, wherein the enhancer promotes the hydrophobicity of impurities in the electrode material, and the step of flotation forms a hydrophilic phase containing the electrode material and a hydrophobic phase containing impurities A step of separating the hydrophobic phase from the hydrophilic phase, and A step of applying a second heat treatment to the electrode material to produce a regenerated electrode material, wherein the second heat treatment vaporizes at least about 95% by weight of the binder remaining in the electrode material A method comprising

13. Before the first heat treatment, a step of removing oxidizable impurities from the electrode material by treatment with at least one of an acid having a pH of about 4 or less or a base having a pH of at least about 13 The method according to claim 12, further comprising

14. The electrode material is LiCoO ２ , LiMn ２ O ４ , LiFe ｔ M １－ｔ PO ４ Or LiNi ａ Mn ｂ Co ｃ A ｄ O ２ And includes at least one of them, where a + b + c + d = 1, A = Al, Zr or Mg, The method according to claim 12.

15. A step of applying a liquid to the electrode material to remove a surface coating agent and / or surface impurities from the electrode material The method according to claim 12, further comprising

16. After the surface treatment, filtering the electrode material to produce a wet electrode and a waste liquid stream The method according to claim 15, further comprising

17. At least one of purification, neutralization, or filtration of the waste liquid stream The method according to claim 16, further comprising

18. Applying ultrasonic vibrations to the current collector to remove residual electrode material from the current collector The method according to claim 12, further comprising

19. The method according to claim 12, wherein the step of washing comprises ultrasonic treatment of the battery waste

20. Separating electrode material from the current collector by at least one of rotary sieving, vibration sieving, or ultrasonic sieving, or air jet sieving, wherein the electrode material comprises a hydrophobic binder Crushing and / or milling the electrode material to form electrode powder Applying a first heat treatment to the electrode powder at a temperature between about 100 °C and about 700 °C for a duration between about 1 hour and about 6 hours, wherein the first heat treatment decomposes at least a portion of the hydrophobic binder Applying a second heat treatment to the electrode powder to produce a regenerated electrode material, wherein the second heat treatment decomposes at least 98 wt% of the hydrophobic binder present in the electrode material before the first heat treatment A method comprising

21. The method according to claim 20, further comprising collecting fines from the exhaust air resulting from the separating step to produce purified air

22. The step of combining the fine powder and the electrode powder The method according to claim 21, further comprising this step.

23. The electrode material is LiCoO ２ , LiMn ２ O ４ , LiFe ｔ M １－ｔ PO ４ Or LiNi ａ Mn ｂ Co ｃ A ｄ O ２ including at least one of them, where a + b + c + d = 1, A = Al, Zr or Mg, The method according to claim 20.

24. The step of separating the electrode material from the current collector by at least one of tank stirring in water or ultrasonic treatment in water, wherein the electrode material contains a hydrophilic binder, the step, The step of filtering the electrode material to form a wet electrode material and a waste liquid stream The step of drying the wet electrode material to form a dry electrode material, The step of applying a first heat treatment to the dry electrode material, wherein the first heat treatment vaporizes at least about 80% by weight of the hydrophilic binder, the step, and The step of applying a second heat treatment to the dry electrode material to produce a regenerated electrode material, wherein the second heat treatment has a duration between about 1 hour and about 15 hours and a temperature between about 450 °C and about 900 °C, the step including the method.

25. The step of applying ultrasonic vibration to the current collector to remove residual electrode material The method according to claim 24, further comprising this step.

26. At least one of purification, neutralization or filtration of the waste liquid stream The method according to claim 24, further comprising **Claim 27** The step of adding the waste liquid stream to the water The method according to claim 26, further comprising

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