System and method for removing and recycling aluminum impurities from battery waste

Abstract

Embodiments described herein relate to removal of aluminum impurities from battery waste. In some aspects, a method for removing aluminum impurities includes pre-processing an amount of battery waste to improve removal of aluminum impurities from the amount of battery waste. The method further includes removing at least a portion of the aluminum impurities from the amount of battery waste, modifying the removed aluminum impurities to form a coating precursor and / or a doping precursor, and applying the coating precursor and / or the doping precursor to an electrode material. In some embodiments, the method further includes characterizing the aluminum impurities in the amount of battery waste and regenerating the electrode material. In some embodiments, the removal may occur via screening, cyclonic separation, air separation, elutriation, and / or dissolution. In some embodiments, the doping precursor may include aluminum hydroxide (Al (OH) 3). In some embodiments, the regeneration includes applying a thermal treatment to the electrode material.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to U.S. Provisional Application No. 63 / 509,661, filed June 22, 2023, entitled “Systems and Methods for the Removal and Recycling of Aluminum Impurities from Battery Waste,” the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The embodiments described herein relate to apparatus, systems, and methods for removing and recycling aluminum impurities from battery waste. Background Technology

[0004] Lithium-ion batteries (LIBs) are widely used in portable electronic devices, electric vehicles, and grid energy storage due to their low self-discharge rate, high energy and power density, and long cycle life. The LIB market is expected to continue growing. Among cathode active materials, olivine-type lithium iron phosphate (LiFePO4, also known as LFP) and its derivatives have attracted considerable attention and possess several significant advantages compared to their counterparts. LFP and its derivatives are inherently safer, cheaper, and highly durable when used as cathode materials in LIBs compared to other cathode materials. However, the LIB production process leads to the formation of undesirable byproducts. Capturing and utilizing these byproducts can significantly improve the efficiency of the entire LIB production process. Summary of the Invention

[0005] The embodiments described herein relate to the removal of aluminum impurities from battery waste. In some aspects, a method for removing aluminum impurities includes preprocessing a quantity of battery waste to improve the removal of aluminum impurities from the quantity of battery waste. The method further includes removing at least a portion of the aluminum impurities from the quantity of battery waste, modifying the removed aluminum impurities to form a coating precursor and / or a doping precursor, and applying the coating precursor and / or the doping precursor to an electrode material. In some embodiments, the method further includes characterizing the aluminum impurities in the quantity of battery waste and regenerating the electrode material. In some embodiments, removal may be performed via sieving, cyclone separation, air separation, panning, and / or dissolution. In some embodiments, the doping precursor may include aluminum hydroxide (Al(OH)3). In some embodiments, regeneration includes applying a heat treatment to the electrode material.

[0006] In some embodiments, recycling battery waste containing electrode materials and aluminum impurities includes: modifying the aluminum impurities to form a precursor; and incorporating the precursor into the electrode material.

[0007] In some embodiments, a method for regenerating electrode material includes: obtaining battery waste containing electrode material and aluminum impurities; and regenerating the electrode material by incorporating at least a portion of the aluminum impurities into the electrode material. Attached Figure Description

[0008] Figure 1 This is a flowchart of a method for removing aluminum (Al) from battery waste according to an embodiment.

[0009] Figure 2 The X-ray diffraction (XRD) patterns of Al-doped lithium iron phosphate (LFP) samples and standard LFP materials are shown.

[0010] Figure 3 The changes in lattice parameters of Al-doped LFP samples compared to standard LFP materials are shown.

[0011] Figure 4 The rate performance of the Al-doped LFP sample compared to the standard LFP material is shown. Detailed Implementation

[0012] Effective recycling of lithium-ion batteries can help recover materials for reuse. These materials can be incorporated into the manufacture of new lithium-ion batteries. This can reduce greenhouse gas emissions, energy consumption, and the economic costs associated with lithium-ion battery production. Direct recycling can recover valuable cathode materials in a non-destructive manner, preserving the structure, morphology, and electrochemical properties of the electrode materials. Aluminum impurities in electrode materials may originate from the casing material, degradation of previous aluminum-based additives or coating compounds, cutting / shredding machinery, and / or aluminum current collectors. The presence of aluminum impurities in electrode materials can lead to unsatisfactory electrochemical performance.

[0013] While lithium-ion batteries have become an essential component in the introduction of sustainable energy technologies such as solar and wind power, and electric vehicles, their manufacturing, use, and disposal generate substantial amounts of waste. Recycling battery materials can reduce the environmental impact of lithium-ion batteries. Furthermore, recycled battery materials can be a significant source of materials for use in new battery manufacturing processes. This can reduce demand, socio-environmental impact, and the costs associated with the mining and manufacturing of new battery materials.

[0014] Direct recycling of battery waste is a method that directly recovers electrode materials and other battery waste (such as current collectors, binders, and electrolytes) for reuse. Direct recycling is non-destructive and preserves the structure, morphology, and electrochemical properties of valuable battery materials. In many cases, direct recycling can provide additional advantages over other recycling processes. These advantages can include modification or upgrading of battery materials to produce battery materials with improved morphology, structure, processing characteristics, safety characteristics, and electrochemical or other performance properties.

[0015] The systems and methods described herein relate to the direct recycling of batteries and battery waste. Direct recycling involves processing batteries and battery waste through multiple steps to separate, purify, and / or regenerate one or more recyclable battery components, such as electrode materials. Furthermore, direct recycling may include procedures for incorporating intentionally generated or introduced impurities during the recycling process. Such impurities may include aluminum impurities. Introducing these impurities into recycled battery materials can hinder advantages in safety, processing characteristics, and performance.

[0016] As used in this specification, "battery waste" can include waste battery materials, battery manufacturing waste, defective batteries, or subsets thereof. For example, battery waste can include electrode materials, separator materials, current collector materials, electrolytes, lithium salts, packaging materials, or any combination thereof.

[0017] As used herein, "electrode material" can refer to active material, conductive material, binder, or any combination thereof. For example, electrode material can refer only to active material, active material and conductive material, active material and binder, conductive material and binder, or active material, conductive material, and binder. Electrode material can include anode material and / or cathode material. In some embodiments, electrode material can include cathode active material, cathode conductive material, cathode binder, cathode current collector material, or any combination thereof. In some embodiments, electrode material can include anode active material, anode conductive material, anode binder, anode current collector material, or any combination thereof. For example, electrode material can include cathode active material, cathode conductive material, cathode binder, cathode current collector material, anode active material, anode conductive material, anode binder, anode current collector material, or any combination thereof.

[0018] As used in this specification, the singular forms “a,” “an,” and “the” include plural indicators unless the context clearly indicates otherwise. Thus, for example, the term “component” is intended to mean a single component or a combination of components, and “material” is intended to mean one or more materials or a combination thereof.

[0019] When used in conjunction with "cylindrical," "linear," and / or other geometric relationships, the term "substantially" is intended to express that a structure is nominally cylindrical, linear, etc., as defined. As an example, a portion of a support member described as "substantially linear" is intended to express that while linearity is desired in that portion, some non-linearity may occur within the "substantially linear" section. Such non-linearity can arise from manufacturing tolerances or other practical considerations, such as, for example, pressure or force applied to the support member. Therefore, a geometry modified by the term "substantially" includes such geometric characteristics within a tolerance of plus or minus 5% of the linearity. For example, a "substantially linear" portion is a portion defined as an axis or centerline within a 5% tolerance of linearity.

[0020] As used herein, the terms “group” and “multiple” can refer to multiple features or a single feature having multiple parts. For example, when referring to a group of electrodes, the group of electrodes can be considered as a single electrode having multiple parts, or the group of electrodes can be considered as multiple different electrodes. Additionally, for example, when referring to multiple electrochemical cells, the multiple electrochemical cells can be considered as multiple different electrochemical cells or a single electrochemical cell having multiple parts. Thus, a group of parts or multiple parts can include multiple parts that are continuous or discontinuous with each other. Multiple particles or multiple materials can also be manufactured from multiple separately produced and subsequently joined together (e.g., via mixing, adhesives, or any suitable method) of articles.

[0021] Some embodiments described herein may include any aspect of recycling in U.S. Patent No. 11,631,909 (“909 Patent”), filed November 26, 2019, entitled “Methods and Systems for Scalable Direct Recycling of Batteries”, the disclosure of which is incorporated herein by reference in its entirety. Some embodiments described herein may include any aspect of recycling in U.S. Patent Application No. 18 / 314,873 (“873 Application”), filed May 10, 2023, entitled “Methods and Systems for Scalable Direct Recycling of Battery Waste”, the disclosure of which is incorporated herein by reference in its entirety.

[0022] Figure 1This is a flowchart of a method 10 for removing and / or modifying aluminum (Al) from battery waste according to one embodiment. As shown, method 10 includes preprocessing the battery waste at step 11 to improve characterization, aluminum removal, and aluminum modification. Method 10 optionally includes characterizing aluminum impurities in the battery waste at step 12. Method 10 further includes removing aluminum impurities from the battery waste at step 13, modifying the aluminum impurities at step 14 to form precursors (e.g., coating and / or doping precursors), and incorporating the precursors into electrode material at step 15. Method 10 optionally includes regenerating the electrode material at step 16. In some embodiments, method 10 may be performed in a system or facility that may include one or more subsystems for performing each method step. More specifically, steps 11, 12, 13, 14, 15, and 16 may each be performed in a subsystem of a main system or facility.

[0023] In some embodiments, the battery waste processed via method 10 may include electrode materials (e.g., waste electrode materials). In some embodiments, the electrode materials may include Li x M y PO4, where M is a transition metal and x and y are positive real numbers. In some embodiments, the electrode material may include LFP. In some embodiments, the electrode material may include a doped or mixed metal derivative of LFP (e.g., LiMnO4). x Fe 1-x PO 4, Or Li 1-x M x PO4). In some embodiments, battery waste may include waste from lithium cobalt oxide (LCO) batteries, lithium nickel cobalt manganese oxide (NCM) batteries, lithium nickel cobalt aluminum oxide (NCA) batteries, and / or lithium manganese oxide (LMO) batteries. In some embodiments, electrode materials may include LiCoO2, LiMn2O4, LiFe... t M 1-t PO4 or LiNi a Mn b Co c A d O2, where a+b+c+d = 1; where 0 < t < 1; where M includes metallic elements; and where A = Al, Zr, or Mg.

[0024] In some embodiments, the battery waste being processed may include aluminum impurities in the form of alumina (Al₂O₃), (Al(OH)₃), or any combination thereof. In some embodiments, method 10 may produce commercial-grade electrode materials. In some embodiments, method 10 may produce electrode materials free of any form of aluminum. In some embodiments, method 10 may produce electrode materials free of aluminum impurities but having an aluminum compound surface coating and / or aluminum doping.

[0025] Step 11 includes preprocessing battery waste to improve characterization, aluminum removal, and aluminum modification. Preprocessing prepares electrode materials for efficient subsequent operations. In some embodiments, step 11 may include collecting electrode materials from the battery waste stream. In some embodiments, the battery waste stream may include used, defective, scrapped, or end-of-life lithium-ion batteries, or combinations thereof. In some embodiments, the battery waste stream may include electrode scrapping materials. In some embodiments, electrode scrapping materials may include at least one electrode material. In some embodiments, electrode scrapping materials may include at least one current collector material. In some embodiments, electrode scrapping materials may include black matter or other shredded, ground, milled, sliced, or otherwise mechanically processed battery waste. In some embodiments, the battery waste stream may include any combination of the electrode forms described above. In some embodiments, the collection of electrode materials may include any processes and apparatus described in '909 patent and '873 application' (e.g., washing, separation, screening, flotation). In some embodiments, step 11 may include partially or completely removing other impurities from the electrode materials, such as anode, carbon, binder, electrolyte, casing material, separator, aluminum, and / or copper. In some embodiments, step 11 may include reducing the size of the electrode material and aluminum impurities to produce a more uniform and homogeneous mixture. In some embodiments, the size of the electrode material and / or aluminum impurities may be reduced by methods such as shredding, cutting, grinding, and / or crushing. In some embodiments, step 11 may include separating the anode active material, anode conductive material, anode binder, or any combination thereof from other battery waste components. In some embodiments, step 11 may include separating the cathode active material, cathode conductive material, cathode binder, anode active material, anode conductive material, anode binder, or any combination thereof from other battery waste components. In some embodiments, step 11 may include separating the cathode active material, cathode conductive material, cathode binder, anode active material, anode conductive material, anode binder, or any combination thereof from other battery waste components.

[0026] Step 11 may include the separation and recycling of electrode materials (e.g., active materials with binders and / or conductive materials with impurities). If the materials are still battery waste at the end of Step 11 (i.e., containing electrode materials and other components such as membrane materials and / or current collector materials), then Step 12 and subsequent steps can be applied.

[0027] In step 12, method 10 optionally includes characterizing aluminum impurities in battery waste. This characterization can help understand the morphology, crystal structure, chemical composition, oxidation state, and / or any other properties of aluminum impurities in the electrode material. In some embodiments, characterization may include using scanning electron microscopy (SEM) to analyze the surface morphology and / or distribution of aluminum impurities in the electrode material. In some embodiments, in conjunction with scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX or EDS) may be used to assess the weight percentage of aluminum impurities in the electrode material. In some embodiments, characterization may include inductively coupled plasma mass spectrometry (ICP-MS) or similar analysis of a solution containing dissolved electrode material to assess the weight percentage of aluminum impurities. In some embodiments, characterization may include X-ray fluorescence (XRF)-based analytical techniques to determine the amount of aluminum impurities in the electrode material. In some embodiments, the characterization of aluminum impurities may be performed via any combination of the above techniques.

[0028] Step 13 includes removing most or all of the aluminum impurities from the electrode material, such as removing substantially all of the aluminum impurities (e.g., removing more than 95% of the aluminum impurities from the electrode material). In some embodiments, aluminum impurities may be physically removed from the electrode material based on their physical properties. In some embodiments, these physical properties may include shape, density, and / or particle size. In some embodiments, aluminum impurities may be removed from the electrode material via a screening surface (e.g., screening, sifting, and / or sifting). In some embodiments, aluminum impurities may be removed from the electrode material via a cyclone separator and / or an air separator. In some embodiments, aluminum impurities may be removed via a panning method. In some embodiments, aluminum impurities may be chemically removed from the electrode material. In some embodiments, aluminum impurities may be dissolved via an alkaline solution and then removed from the electrode material (e.g., via filtration). In some embodiments, the alkaline solution may react with the aluminum impurities without reacting with or altering the properties of other components of the electrode material. In some embodiments, aluminum impurities may be dissolved via a sodium hydroxide (NaOH) and / or potassium hydroxide (KOH) solution. In some embodiments, the alkaline solution may be an aqueous solution. In some embodiments, the alkaline solution may have a pH of at least about 8, at least about 8.5, at least about 9, at least about 9.5, at least about 10, at least about 10.5, at least about 11, at least about 11.5, at least about 12, at least about 12.5, at least about 13, at least about 13.5, or at least about 14. The dissolution of aluminum in NaOH solution produces hydrogen gas and soluble sodium aluminate (NaAlO2).

[0029] In some embodiments, aluminum impurities can be dissolved in a lithium hydroxide (LiOH) solution. In some embodiments, the LiOH solution can have a pH of at least about 8, at least about 8.5, at least about 9, at least about 9.5, at least about 10, at least about 10.5, at least about 11, at least about 11.5, at least about 12, at least about 12.5, at least about 13, at least about 13.5, or at least about 14. In some embodiments, the ratio of the molar number of lithium in the LiOH solution to the molar number of aluminum in the electrode material can be at least about 5:1, at least about 6:1, at least about 7:1, at least about 8:1, at least about 9:1, at least about 10:1, at least about 11:1, at least about 12:1, at least about 13:1, at least about 14:1, or at least about 15:1. In some embodiments, any combination of the above-described alkaline solutions can be used to dissolve and remove aluminum impurities from the electrode material.

[0030] In some embodiments, aluminum impurities may be dissolved via an acid solution (or a combination or sequence of acid solutions) and then removed from the electrode material (e.g., via filtration). In some embodiments, the acid solution may react with the aluminum impurities without reacting with or altering the properties of other components of the electrode material. In some embodiments, the removal of aluminum impurities is carried out in a controlled environment to protect the electrode material. In some embodiments, a reducing environment is created to prevent oxidation of the electrode material (e.g., LFP electrode material and its derivatives). In some embodiments, aluminum impurities may be dissolved via inorganic and organic acids, including but not limited to hydrochloric acid (HCl), sulfuric acid (H2SO4), nitric acid (HNO3), and / or phosphoric acid (H3PO4) solutions, and organic acids including but not limited to acetic acid, citric acid, and / or oxalic acid. In some embodiments, the alkaline solution may be an aqueous solution. In some embodiments, the acid solution may have a pH of not greater than about 6, not greater than about 5.5, not greater than about 5, not greater than about 4.5, not greater than about 4, not greater than about 3.5, not greater than about 3, not greater than about 2.5, not greater than about 2, not greater than about 1.5, not greater than about 1, or not greater than about 0.5.

[0031] In some embodiments, the removal of aluminum impurities from the electrode material in step 13 may 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 removal of aluminum impurities from the electrode material in step 13 may have a duration of no more than about 21 hours, no more than about 19 hours, no more than about 17 hours, no more than about 15 hours, no more than about 13 hours, no more than about 11 hours, no more than about 10 hours, no more than about 9 hours, no more than about 8 hours, no more than about 7 hours, no more than about 6 hours, no more than about 5 hours, no more than about 4 hours, no more than about 3 hours, no more than about 2 hours, no more than about 1 hour, no more than about 55 minutes, no more than about 50 minutes, no more than about 45 minutes, no more than about 40 minutes, no more than about 35 minutes, no more than about 30 minutes, no more than about 25 minutes, no more than about 20 minutes, no more than about 15 minutes, no more than about 10 minutes, no more than about 9 minutes, no more than about 8 minutes, no more than about 7 minutes, no more than about 6 minutes, no more than about 5 minutes, no more than about 4 minutes, no more than about 3 minutes, no more than about 2 minutes, or no more than about 1 minute. Combinations of the above durations are also possible (e.g., at least about 30 seconds and no more than about 21 hours or at least about 5 minutes and no more than about 30 minutes), including all values ​​and ranges therebetween. In some embodiments, the removal of aluminum impurities from the electrode material at step 13 can have durations 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.

[0032] In some embodiments, the removal of aluminum from the electrode material at step 13 can be accelerated by techniques including, but not limited to, heating, ultrasonic treatment, and stirring. In some embodiments, aluminum removal in step 13 can be performed at temperatures 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, aluminum removal in step 13 can be performed at temperatures not exceeding about 100°C, not exceeding about 90°C, not exceeding about 80°C, not exceeding about 70°C, not exceeding about 60°C, not exceeding about 50°C, not exceeding about 40°C, or not exceeding about 30°C. Combinations of the above temperatures are also possible (e.g., at least about 20°C and not exceeding about 100°C or at least about 40°C and not exceeding about 60°C), including all values ​​and ranges therebetween. In some embodiments, the removal of aluminum in step 13 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.

[0033] In some embodiments, the alkaline solution containing dissolved aluminum compounds can be separated from the electrode material via techniques including, but not limited to, filtration, centrifugation, sedimentation, decantation, or combinations thereof. In some embodiments, the electrode material can be washed at least once with water and / or another solvent to remove residual alkaline solution. In some embodiments, a combination of the above methods can be used to remove aluminum impurities partially or completely from the electrode material.

[0034] In some embodiments, the acidic solution containing dissolved aluminum compounds can be separated from the electrode material via techniques including, but not limited to, filtration, centrifugation, sedimentation, decantation, or combinations thereof. In some embodiments, the electrode material can be washed at least once with water and / or another solvent to remove residual alkaline solution. In some embodiments, a combination of the above methods can be used to remove aluminum impurities partially or completely from the electrode material.

[0035] In some embodiments, after step 13, the battery waste may contain less than about 10% by weight, less than about 5% by weight, less than about 1% by weight, less than about 0.5% by weight, less than about 0.1% by weight, less than about 0.05% by weight, less than about 0.01% by weight, less than about 0.005% by weight, less than about 0.001% by weight, less than about 0.0005% by weight, and less than about 0.0001% by weight of aluminum. In some embodiments, after step 13, the electrode material of the battery waste may contain less than about 10% by weight, less than about 5% by weight, less than about 1% by weight, less than about 0.5% by weight, less than about 0.1% by weight, less than about 0.05% by weight, less than about 0.01% by weight, less than about 0.005% by weight, less than about 0.0005% by weight, and less than about 0.0001% by weight of aluminum. In some embodiments, after step 13, the aluminum concentration in the battery waste or electrode material may be reduced to a desired concentration for subsequent aluminum modification (i.e., step 14).

[0036] In some embodiments, step 13 includes partially removing aluminum impurities and then, following the coating / doping operation (i.e., step 14), directly converting the remaining aluminum impurities into an aluminum coating and / or doping of the electrode material. The remaining aluminum impurities can be modified via the methods described herein to form an aluminum precursor. Then, following the coating and / or doping operation (i.e., step 14), the aluminum precursor can be converted into an aluminum coating and / or doping of the electrode material. In some embodiments, the aluminum precursor may include any aluminum-containing compound used to form the doping or coating. Aluminum precursors can be considered reactive compounds because they readily react with the electrode material (e.g., the cathode) upon application of a stimuli (such as lowering or raising the temperature, lowering or increasing the pressure, adding a solvent, or adding a catalyst or other reactive compound). In some embodiments, aluminum impurities can be modified to form an aluminum precursor. Some aluminum impurities may have forms that are less or less reactive with the cathode material (e.g., Al2O3). These can potentially be converted into more reactive aluminum-containing compounds (i.e., aluminum precursors) to be doped and coated onto the cathode. Following the coating and / or doping operation, the aluminum precursor can be converted into an aluminum coating and / or doping of the electrode material. In some embodiments, after the coating / doping operation (i.e., after step 15), aluminum impurities can be directly converted into an aluminum coating and / or doping of the electrode material.

[0037] Step 14 includes modifying the aluminum impurities to form precursors, such as coating and / or doping precursors. For example, the aluminum impurities can be converted into aluminum-based dopant materials for doping into the lattice of the electrode material. In some embodiments, the aluminum impurities can be converted into surface coatings and doping of recycled electrode material. In some embodiments, the aluminum impurities can be converted into aluminum compounds, which are precursors for surface coating and / or doping. These precursors for surface coating and / or doping are then coated and / or doped into the electrode material via techniques such as heat treatment, mechanical fusion, and mechanochemical reactions. In some embodiments, the concentration of aluminum impurities in the dopant and / or coating can be reduced to a desired level via the aluminum impurity removal steps described above with reference to step 13. In some embodiments, the concentration of aluminum in the dopant and / or coating can be increased by adding an aluminum compound or adjusting the amount of aluminum removed during step 13. In some embodiments, the concentration of aluminum impurities in the dopant and / or coating can be increased to a desired level by adding an additional aluminum source (such as aluminum metal and / or aluminum-containing compounds) to the electrode material during step 14. In some embodiments, aluminum can be added at lithium atom sites (i.e., M1 sites) in Li 1-3y Al y FePO4 is incorporated into the LFP electrode. In some embodiments, aluminum can be doped at the iron atom sites (i.e., the M2 sites) as LiFe. 1-1.5y Al y The composition of PO4 is doped.

[0038] In some embodiments, additional precursors or one or more additional precursors for electrode material production, such as Li₂CO₃, LiOH, FePO₄, (NH₄)₂HPO₄, may be added during the Al modification step to achieve the target doping composition. In some embodiments, the additional precursors may include lithium precursors, such as Li₂CO₃, LiOH, or any other suitable lithium precursor, or any suitable combination thereof. In such embodiments, the lithium precursor may react or interact with the aluminum precursor to modify or convert at least a portion of the aluminum precursor into a lithium aluminum (Li-Al) compound precursor, and / or directly incorporate it into the electrode material (e.g., cathode material) to relithiate the electrode material (e.g., incorporate lithium ions, dope, and / or coat the electrode material). In other words, the lithium precursor may be a Li-Al compound and / or lithium incorporated into the electrode material.

[0039] In some embodiments, the coating and / or dopant may have an aluminum concentration of at least about 1% by weight, at least about 5% by weight, at least about 10% by weight, at least about 15% by weight, at least about 20% by weight, at least about 25% by weight, at least about 30% by weight, at least about 35% by weight, at least about 40% by weight, at least about 45% by weight, at least about 50% by weight, at least about 55% by weight, at least about 60% by weight, at least about 65% by weight, at least about 70% by weight, at least about 75% by weight, at least about 80% by weight, at least about 85% by weight, at least about 90% by weight, at least about 95% by weight, at least about 96% by weight, at least about 97% by weight, at least about 98% by weight, at least about 99% by weight, at least about 99% by weight, at least about 99.5% by weight, at least about 99.6% by weight, at least about 99.7% by weight, at least about 99.8% by weight, at least about 99.9% by weight, at least about 99.99% by weight, or at least about 99.999% by weight. In some embodiments, the coating and / or dopant may be pure aluminum. In some embodiments, the coating and / or dopant may have an aluminum concentration of not more than about 99.999% by weight, not more than about 99.99% by weight, not more than about 99.9% by weight, not more than about 99.8% by weight, not more than about 99.7% by weight, not more than about 99.6% by weight, not more than about 99.5% by weight, not more than about 99% by weight, not more than about 98% by weight, not more than about 97% by weight, not more than about 96% by weight, not more than about 95% by weight, not more than about 90% by weight, not more than about 85% by weight, not more than about 80% by weight, not more than about 75% by weight, not more than about 70% by weight, not more than about 65% by weight, not more than about 60% by weight, not more than about 55% by weight, not more than about 50% by weight, not more than about 45% by weight, not more than about 40% by weight, not more than about 35% by weight, not more than about 30% by weight, not more than about 25% by weight, not more than about 20% by weight, not more than about 15% by weight, not more than about 10% by weight, or not more than about 5% by weight. Combinations of the above weight percentages are also possible (e.g., at least about 1% by weight and no more than about 99.999% by weight or at least about 15% by weight and no more than about 40% by weight), including all values ​​and ranges in between.In some embodiments, the coating and / or dopant may have an aluminum concentration of about 1 wt%, about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%, about 80 wt%, about 85 wt%, about 90 wt%, about 95 wt%, about 96 wt%, about 97 wt%, about 98 wt%, about 99 wt%, about 99.5 wt%, about 99.6 wt%, about 99.7 wt%, about 99.8 wt%, about 99.9 wt%, about 99.99 wt%, or about 99.999 wt%.

[0040] In some embodiments, aluminum impurities can be converted into lithium / aluminum layered double hydroxide compounds as doping precursors. In some embodiments, aluminum impurities can be converted into lithium / aluminum layered double hydroxide compounds by first reacting them with a LiOH solution. In some embodiments, the LiOH solution may have a pH of at least about 8, at least about 8.5, at least about 9, at least about 9.5, at least about 10, at least about 10.5, at least about 11, at least about 11.5, at least about 12, at least about 12.5, at least about 13, at least about 13.5, or at least about 14 to react with the aluminum impurities. In some embodiments, metallic aluminum can react with the LiOH solution to form a lithium-aluminum layered double hydroxide having the formula [LiAl2(OH)6]OH·H2O. In some embodiments, the lithium-aluminum layered double hydroxide can generate hydrogen gas. In some embodiments, Al2O3 can react with the LiOH solution to form a lithium / aluminum layered double hydroxide having the formula [LiAl2(OH)6]OH·H2O. In some embodiments, the molar ratio of aluminum to lithium in the conversion reaction may be less than about 2. A lithium / aluminum layered double hydroxide can be formed, and excess lithium can be retained in solution as LiOH. In some embodiments, the molar ratio of aluminum to lithium used in the conversion reaction can be about 2. In some embodiments, only the lithium / aluminum layered double hydroxide is formed at the end of the reaction, and no additional soluble lithium is present in the reaction medium. In some embodiments, the molar ratio of aluminum to lithium used in the conversion reaction can be greater than about 2. In some embodiments, both the lithium / aluminum layered double hydroxide and aluminum hydroxide can be formed at the end of the reaction.

[0041] In some embodiments, the conversion reaction between aluminum and LiOH can be accelerated by techniques including, but not limited to, heating, ultrasonic treatment, and stirring. In some embodiments, the conversion reaction can be carried out at temperatures 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 conversion reaction can be carried out at temperatures not exceeding about 100°C, not exceeding about 90°C, not exceeding about 80°C, not exceeding about 70°C, not exceeding about 60°C, not exceeding about 50°C, not exceeding about 40°C, or not exceeding about 30°C. Combinations of the above temperatures are also possible (e.g., at least about 20°C and not exceeding about 100°C or at least about 40°C and not exceeding about 60°C), including all values ​​and ranges therebetween. In some embodiments, the conversion reaction can be carried out at temperatures 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.

[0042] LiOH solution (in the form of lithium / aluminum layered double hydroxide or LiOH after the conversion reaction) can also be used as a lithium source to compensate for lithium deficiency in the electrode material via a regeneration step, as described below. In some embodiments, the amount of lithium in the added LiOH solution can be stoichiometric to match the aluminum-doped composition (i.e., Li...). 1-3y Al y FePO4 or LiFe 1-1.5y Al y (PO4). In some embodiments, the liquid may evaporate from the solution after the conversion reaction. In some embodiments, the size of the precursors for surface coating and / or doping may be reduced and / or thoroughly mixed before commencing coating and / or doping operations. In some embodiments, size reduction and / or mixing may be performed using equipment such as planetary ball mills, horizontal ball mills, nanobead mills, air jet mills, and / or other similar grinding, milling, or shredding processes or combinations thereof.

[0043] In some embodiments, aluminum impurities can be converted into Al(OH)3 as a doping precursor. In some embodiments, aluminum impurities can be converted into Al(OH)3 by first reacting with KOH and / or NaOH solutions. In some embodiments, the KOH and / or NaOH solutions can have a pH of at least about 8, at least about 8.5, at least about 9, at least about 9.5, at least about 10, at least about 10.5, at least about 11, at least about 11.5, at least about 12, at least about 12.5, at least about 13, at least about 13.5, or at least about 14 to react with the aluminum impurities. In some embodiments, metallic aluminum can react with NaOH solution to form soluble NaAlO2 and generate hydrogen gas. In some embodiments, Al2O3 can react with NaOH solution to form soluble sodium aluminate (NaAl(OH)4) and / or potassium aluminate (Kal(OH)4). In some embodiments, soluble NaAl(OH)4 and / or Kal(OH)4 may then react with carbon dioxide to form soluble sodium carbonate (Na2CO3) and / or soluble potassium carbonate (K2CO3). In some embodiments, reaction with carbon dioxide may form soluble sodium bicarbonate (NaHCO3) and / or soluble potassium bicarbonate (KHCO3). In some embodiments, soluble NaAl(OH)4 and / or Kal(OH)4 may also react with acids (e.g., HCl, H2SO4, or organic acids such as acetic acid, oxalic acid) to produce Al(OH)3 precipitate. The solubility of Al(OH)3 reaches its minimum at a pH of about 7. In some embodiments, the pH of the solution may be adjusted to about 7 (e.g., between about 6 and about 8, between about 5 and about 9, between about 5 and about 8, or between about 6 and about 9) to increase the efficiency or amount of Al(OH)3 precipitation.

[0044] In some embodiments, pH can be used as a decisive factor indicating the completion of the conversion reaction. For example, the conversion reaction may end when the pH of the solution is less than about 13, less than about 12.5, less than about 12, less than about 11.5, less than about 11, less than about 10.5, less than about 10, less than about 9.5, less than about 9, less than about 8.5, less than about 8, less than about 7.5, or less than about 7 (inclusive of all values ​​and ranges therein). In some embodiments, the precipitation of aluminum from the solution can be controlled by appropriately controlling the pH of the solution. Controlling aluminum precipitation can provide the resulting aluminum-doped electrode material with a desired chemical composition (e.g., Li). 1- 3y Al y FePO4 or LiFe 1-1.5y Al yAl(OH)3 is an alternative to PO4. After Al(OH)3 precipitation, the solution can be removed, leaving the Al(OH)3 precursor and electrode material. In some embodiments, the solution may contain soluble sodium-containing and / or potassium-containing salts (e.g., NaOH, KOH, NaAlO2, KalO2, Na2CO3, K2CO3, NaHCO3, and KHCO3). In some embodiments, the liquid may be separated from the aluminum-containing material by filtration, centrifugation, precipitation, decantation, or any combination thereof. In some embodiments, the mixture of electrode material and Al(OH)3 precursor is washed at least once with water or other solvents to remove residual sodium and / or potassium salts from the mixture. In some embodiments, the surface coating and / or doping precursor may be reduced in size and / or thoroughly mixed before entering the coating and / or doping operation. In some embodiments, the reduction in size and / or mixing may be performed via equipment such as a planetary ball mill, a horizontal ball mill, a nanobead mill, an air jet mill, or any combination thereof.

[0045] In some embodiments, metallic aluminum can be converted into aluminum alkoxide (Al(RO)3) as a doping precursor, wherein R is an alkyl group (e.g., methyl, ethyl, propyl). In some embodiments, metallic aluminum can be converted into aluminum alkoxide (Al(RO)3) by reacting metallic aluminum with an organic compound (i.e., an alcohol) having at least one hydroxyl (-OH) functional group. In some embodiments, the organic compound may include methanol (CH3OH). Metallic aluminum can react with methanol to form aluminum methoxide (Al(OCH3)3), which can be used as a doping precursor. In some embodiments, the organic compound may include ethanol (C2H5OH). Metallic aluminum can react with ethanol to form aluminum ethoxide (Al(OC2H5)3), which can be used as a doping precursor. In some embodiments, the organic compound may include n-propanol or isopropanol (C3H7OH). Metallic aluminum can react with n-propanol or isopropanol to form aluminum isopropoxide (Al(Oi-Pr)3), which can be used as a doping precursor, wherein i-Pr is an isopropyl group (–CH(CH3)2). In some embodiments, the surface coating and / or doping precursor are reduced in size and / or thoroughly mixed before proceeding to the coating and / or doping operation. In some embodiments, the reduction in size and / or mixing is performed using equipment such as a planetary ball mill, a horizontal ball mill, a nanobead mill, an air jet mill, other grinding, shredding, or milling processes, or combinations thereof.

[0046] In some embodiments, aluminum impurities can be converted into LiAlO2 as a coating precursor. In some embodiments, aluminum impurities are converted into LiAlO2 by first reacting with oxygen. In some embodiments, metallic aluminum can react with oxygen to form Al2O3. In some embodiments, Al2O3 and / or Al(OH)3 can react with an additional lithium source (e.g., LiOH, Li2CO3) to form LiAlO2. In some embodiments, the additional lithium source can include LiOH, Li2CO3, or any combination thereof. In some embodiments, the amount of lithium source added exceeds the stoichiometric amount to react with Al2O3 and / or Al(OH)3. In some embodiments, the added excess lithium source can compensate for lithium defects in the electrode material to be regenerated. In some embodiments, the amount of lithium source added may be about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2, about 2.5, about 3, about 3.5, about 4, about 4.5, about 5, about 5.5, about 6, about 6.5, about 7, about 7.5, about 8, about 8.5, about 9, about 9.5, or about 10 times the stoichiometric amount of the lithium source reacting with Al2O3 and / or Al(OH)3, including all values ​​and ranges therein.

[0047] In some embodiments, Al2O3 and / or Al(OH)3 are reacted with a lithium source at a temperature of 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, 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, at least about 1,100°C, or at least about 1,150°C. In some embodiments, Al2O3 and / or Al(OH)3 are reacted with a lithium source at temperatures not exceeding about 1,200°C, 1,150°C, 1,100°C, 1,050°C, 1,000°C, 950°C, 900°C, 850°C, 750°C, 700°C, 650°C, 550°C, 500°C, or 450°C. Combinations of the above temperatures are also possible (e.g., at least about 400°C and not exceeding about 1,200°C or at least about 600°C and not exceeding about 1,000°C), including all values ​​and ranges therebetween. In some embodiments, Al2O3 and / or Al(OH)3 are reacted with a lithium source at temperatures of 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, about 1,150°C, or about 1,200°C.

[0048] In some embodiments, the reaction to form LiAlO2 is carried out in a controlled atmosphere, such as an oxidizing environment, an inert environment, or a reducing environment. In some embodiments, metallic aluminum can be converted into an aluminum alkoxide, such as aluminum isopropoxide (Al(Oi-Pr)3) as described above. In some embodiments, the aluminum alkoxide (Al(RO)3) is then reacted with an additional lithium source, such as lithium carbonate and / or lithium hydroxide, to form a LiAlO2 precursor. In some embodiments, the surface coating and / or doping precursor can be reduced in size and / or thoroughly mixed before entering the coating and / or doping operation. In some embodiments, the reduction in size and / or mixing is performed using equipment such as a planetary ball mill, a horizontal ball mill, a nanobead mill, an air jet mill, other grinding, shredding, or milling processes, or combinations thereof.

[0049] Step 15 includes incorporating (e.g., applying) a precursor (e.g., coating and / or doping precursor) into the electrode material. Applying a coating and / or doping precursor can improve the performance of the electrode material. In some embodiments, the coating and / or doping can be performed via heat treatment. In some embodiments, the coating precursor is uniformly mixed or distributed on the surface of the electrode material via additional processing steps such as crushing, milling, grinding, and / or mechanical fusion.

[0050] In some embodiments, doping and / or coating may be performed at temperatures of 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, 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, at least about 1,100°C, or at least about 1,150°C. In some embodiments, doping or coating may be performed at temperatures not exceeding about 1,200°C, not exceeding about 1,150°C, not exceeding about 1,100°C, not exceeding about 1,050°C, not exceeding about 1,000°C, not exceeding about 950°C, not exceeding about 900°C, not exceeding about 850°C, not exceeding about 800°C, not exceeding about 750°C, not exceeding about 700°C, not exceeding about 650°C, or not exceeding about 600°C, not exceeding about 550°C, not exceeding about 500°C, or not exceeding about 450°C. Combinations of the above temperatures are also possible (e.g., at least about 400°C and not exceeding about 1,200°C or at least about 600°C and not exceeding about 1,000°C), including all values ​​and ranges therebetween. In some embodiments, doping and / or coating may be performed at temperatures of 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, about 1,150°C, or about 1,200°C.

[0051] In some embodiments, doping and / or coating may be performed in a controlled gaseous environment. In some embodiments, the gaseous environment may be inert. In some embodiments, the gaseous environment may include nitrogen, argon, neon, or other similar inert environments. In some embodiments, the gaseous environment may include CO2. In some embodiments, the gaseous environment may be a reducing environment. In some embodiments, the gaseous environment may include a mixture of H2, Ar, and H2, a mixture of N2 and H2, a mixture of CO2 and CO, or any combination thereof. In some embodiments, the gaseous environment may include an oxidizing environment. An oxidizing environment can help remove organic compounds. In some embodiments, air or other gases described above flow along or through the battery waste during purification. In some embodiments, no gas flows along or through the battery waste during purification. In some embodiments, surface treatment may be performed at positive (i.e., above atmospheric pressure) pressure (e.g., about 0.05 bar (gauge pressure), about 0.1 bar, about 0.2 bar, 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, or about 1 bar, including all values ​​and ranges therein). In some embodiments, the surface treatment can be performed at negative (i.e., less than atmospheric) pressure (e.g., about -0.05 bar (gauge pressure), about -0.1 bar, about -0.2 bar, 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, or about -1 bar, including all values ​​and ranges therein). In some embodiments, a reducing agent or an oxidizing agent may be added and thoroughly mixed with the electrode material prior to the doping and / or coating operations to create a reducing or oxidizing environment.

[0052] Step 16 is optional and includes regenerating the electrode material. Regeneration can help recover structural defects or compositional losses from the electrode material. In some embodiments, regeneration may include heat treatment. In some embodiments, heat treatment improves the purity of the electrode material by thermally decomposing or vaporizing carbon or other organic compounds present in the electrode material. In some embodiments, regeneration may include a relithiation process to compensate for lithium loss in the electrode material. In some embodiments, relithiation of the electrode material may be accomplished via solid-state synthesis during heat treatment. In some embodiments, the relithiation process may include uniformly mixing the electrode material with one or more types of lithium sources (e.g., Li₂CO₃, LiOH, lithium hydroxide monohydrate (LiOH·H₂O)) prior to heat treatment. In some embodiments, the lithium source may be thoroughly mixed with the electrode material.

[0053] In some embodiments, the regeneration of electrode material can be performed via a coating process. The coating process may include the regeneration of electrode material. In some embodiments, coating may be performed alone in a direct recycling system without other regeneration operations. In some embodiments, coating may be performed in combination with other regeneration operations in a direct recycling system. In some embodiments, the regeneration of electrode material can be performed via a doping process. In some embodiments, the doping process may be performed alone without other regeneration operations. In some embodiments, doping may be performed in combination with other regeneration operations. This may include at least one doping operation followed by at least one regeneration operation. In some embodiments, aluminum impurities, or at least a portion of aluminum impurities, may be directly converted into a surface coating and / or doping of the electrode material without conversion into any coating and / or doping precursor. In other words, method 10 may skip from step 12 to step 16 without removing aluminum impurities or applying a doping / coating precursor. In some embodiments, aluminum impurities, or at least a portion of aluminum impurities, may be converted into a coating and / or doping via a high-intensity, high-speed, or high-energy mixer or mechanical fusion apparatus.

[0054] In some embodiments, regeneration may be performed at temperatures of at least 400°C, at least 450°C, at least 500°C, at least 550°C, at least 600°C, at least 650°C, at least 700°C, at least 750°C, at least 800°C, at least 850°C, at least 900°C, at least 950°C, at least 1000°C, at least 1050°C, and at least 1100°C. In some embodiments, regeneration may be performed at temperatures not exceeding about 1200°C, not exceeding about 1100°C, not exceeding about 1050°C, not exceeding about 1000°C, not exceeding about 950°C, not exceeding about 900°C, not exceeding about 850°C, not exceeding about 800°C, not exceeding about 750°C, not exceeding about 700°C, not exceeding about 650°C, not exceeding about 600°C, not exceeding about 550°C, not exceeding about 500°C, or not exceeding about 450°C. Combinations of the above temperatures are also possible (e.g., at least about 400°C and no more than about 1200°C or at least about 500°C and no more than about 550°C), including all values ​​and ranges therein. In some embodiments, regeneration can be performed at temperatures of about 400°C, about 500°C, about 600°C, about 700°C, about 800°C, about 900°C, about 1000°C, about 1100°C, or about 1200°C.

[0055] In some embodiments, regeneration may be performed in a controlled gaseous environment. In some embodiments, the gaseous environment may be inert. In some embodiments, the gaseous environment may include nitrogen, argon, neon, or other similar inert environments. In some embodiments, the gaseous environment may include CO2. In some embodiments, the gaseous environment may be a reducing environment. In some embodiments, the gaseous environment may include a mixture of H2, Ar, and H2, a mixture of N2 and H2, a mixture of CO2 and CO, or any combination thereof. In some embodiments, the gaseous environment may include an oxidizing environment. An oxidizing environment can help remove organic compounds. In some embodiments, air or other gases described above flow along or through the battery waste during purification. In some embodiments, no gas flows along or through the battery waste during purification. In some embodiments, surface treatment may be performed at positive (i.e., above atmospheric pressure) pressure (e.g., about 0.05 bar (gauge pressure), about 0.1 bar, about 0.2 bar, 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, or about 1 bar, including all values ​​and ranges therein). In some embodiments, surface treatment can be performed at negative (i.e., less than atmospheric) pressure (e.g., about -0.05 bar (gauge pressure), about -0.1 bar, about -0.2 bar, 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, or about -1 bar, including all values ​​and ranges therein). In some embodiments, prior to regeneration operations, a reducing agent or an oxidizing agent can be added and thoroughly mixed with the electrode material to create a reducing or oxidizing environment.

[0056] Example

[0057] LFP is first formed by reacting with a stoichiometric amount of sodium persulfate in an aqueous solution to form Li. 0.92 FePO4 and Li 0.83 The LFP material was chemically delithilated using FePO4. The delithilated LFP material was washed twice with water to remove residual sodium salts. The chemical composition of the delithiated LFP material and the standard LFP material was analyzed by inductively coupled plasma mass spectrometry (ICP-MS), and the results are shown in Table 1.

[0058] Table 1. ICP-MS results of delithiated LFP materials and standard LFP materials.

[0059]

[0060] Aluminum (alone or mixed with the delithiated LFP material described above) was dissolved in a 0.5 M NaOH solution. After the Al was completely dissolved, CO2 was pumped into the solution, and the formation of a white Al(OH)3 precipitate powder was observed. CO2 pumping was stopped when the pH of the solution reached 7. The white Al(OH)3 precipitate powder (along with the mixed delithiated LFP material, if applicable) was collected by filtration. The collected powder was washed twice with water to remove residual sodium salts.

[0061] If it has not yet been mixed with Al(OH)3, then the chemically delithiated LFP material (chemical composition Li) will be used. 0.92 FePO4 and Li 0.83 FePO4) is thoroughly mixed with stoichiometric amounts of Al(OH)3 to form a compound with Li 0.92 Al 0.027 FePO4 and Li 0.83 Al 0.058 The final chemical composition of FePO4 was matched with that of the mixture. When the delithiated LFP was mixed with aluminum at the start of the process, a 10 wt% glucose solution was also thoroughly mixed with the delithiated LFP material and Al(OH)3. Table 2 shows the ICP-MS results for several doped samples. Doping was designed to dope Al at Li sites and compensate for the charge balance with lithium vacancies. The mixture was formed into disks via a hydraulic press, sintered at 300 °C for 4 hours, and then sintered at 650 °C for 10 hours in a N2 atmosphere. Aluminum was shown to be incorporated into the lattice of the LFP material. The crystal structures of the two aluminum-doped LFP samples (2.7 mol% and 5.8 mol%, respectively) were analyzed by X-ray diffraction (XRD), as shown below. Figure 2 As shown, the aluminum-doped LFP sample exhibits all the characteristic peaks of the standard LFP material, and no impurity phase was detected by XRD.

[0062] Table 2. ICP-MS results of delithiated LFP materials and standard LFP materials.

[0063]

[0064] Figure 3The variation of lattice parameters in Al-doped LFP samples compared to standard LFP materials is shown. The cell parameters of both the Al-doped samples and standard LFP materials were calculated from XRD patterns using the GSAS-II software package with Rietveld enhancement. (Toby, Brian H. et al., “GSAS-II: the genesis of a modern open-source allpurpose crystallography software package.” Journal of Applied Crystallography 46.2 (2013): 544-549.) Figure 4As shown in the figure, with increasing Al doping concentration, increases in lattice constants a, c, and cell volume were observed. This observation is consistent with experimental and simulation results from other published literature. (1) Meethong, Nonglak et al. "Aliovalent substitutions in olivine lithium ironphosphate and impact on structure and properties." Advanced FunctionalMaterials 19.7 (2009): 1060-1070. (2) Molenda, Janina et al. "Structural, transport and electrochemical properties of LiFePO4 substituted in lithiumand iron sublattices (Al, Zr, W, Mn, Co and Ni)."Materials 6.5 (2013): 1656-1687. (3) Chu-Ying, Ouyang et al. "First principles study on NaxLi1− xFePO4 ascathode material for rechargeable lithium batteries." Chinese Physics Letters23.1 (2006): 61. (4) Xu, Jing and Gang Chen. "Effects of doping on theelectronic properties of LiFePO4: A first-principles investigation."PhysicaB: Condensed Matter 405.3 (2010): 803-807. A linear change in the lattice parameter was observed, consistent with Vigarde's law.

[0065] The electrochemical performance of aluminum-doped LFP material was measured in a CR-2032 coin cell, which consisted of a lithium metal counter electrode, a polypropylene separator, and a 1 M LiPF6 electrolyte in EC / DME (3:7 by volume). The working electrode was prepared by mixing 80 wt% LFP material with 10 wt% PVDF and 10 wt% conductive carbon. The coin cell was charged at a C / 10 rate and discharged at different C rates. The discharge capacity was normalized relative to the discharge capacity at the C / 10 rate, and the results were... Figure 4 As shown in the figure, at high discharge rates, the Al-doped LFP samples exhibit higher capacity retention compared to their discharge capacity at C / 10. The increased Al concentration in the LFP is shown to contribute to this higher capacity retention.

[0066] Various concepts can be implemented as one or more methods, with at least one instance provided. Actions performed as part of a method can be ordered in any suitable manner. Thus, embodiments can be constructed in which actions are performed in an order different from the one shown, which may include simultaneous execution of several actions, even if the actions are shown as sequential in the illustrative embodiments. In other words, it should be understood that such features are not necessarily limited to a particular execution order, but can be performed sequentially, asynchronously, concurrently, in parallel, simultaneously, synchronously, and / or in a manner consistent with this disclosure by any number of threads, processes, services, servers, and / or such means. Therefore, some of these features may contradict each other, as they cannot coexist in a single embodiment. Similarly, some features may be applicable to one aspect of the innovation and not to others.

[0067] Furthermore, this disclosure may include other innovations not currently described. The applicant reserves all rights to such innovations, including rights to embody such innovations, file supplemental applications, continuations, partial continuations, divisions, and / or similar rights. Therefore, it should be understood that the advantages, embodiments, examples, functions, features, logic, operation, organization, structure, topology, and / or other aspects of this disclosure should not be considered as limitations on this disclosure as defined by the embodiments or on equivalents of the embodiments. Depending on the specific expectations and / or characteristics of individual and / or enterprise users, database configurations and / or relational models, data types, data transmission and / or network architecture, syntactic structures, and / or similar factors, various embodiments of the technologies disclosed herein can be implemented in a highly flexible and customized manner to achieve the effects described herein.

[0068] It should be understood that all definitions, as defined and used herein, take precedence over dictionary definitions, definitions in referenced documents, and / or the general meaning of the qualified terms.

[0069] As used herein, in certain embodiments, the terms "about" or "approximately" when preceding a numerical value indicate a range of the value plus or minus 10%. Where a range of values ​​is provided, it should be understood that every intermediate value between the upper and lower limits of the range (one-tenth of a unit to the lower limit, unless otherwise explicitly stated) and any other stated or intermediate value within the range is included within this disclosure. The upper and lower limits of these smaller ranges may be independently included in even smaller ranges that are also covered within this disclosure, subject to any specific exclusions imposed on the stated ranges. Where a stated range includes one or both of the included limits, the range excluding any one or both of the included limits is also included within this disclosure.

[0070] The phrase “and / or” as used herein in the specification and embodiments should be understood to mean “any one or both” of the elements so combined, i.e., elements that exist jointly in some cases and separately in others. Multiple elements listed with “and / or” should be interpreted in the same way, i.e., “one or more” of the elements so combined. Other elements may optionally be present, whether related to or unrelated to those specifically identified by the “and / or” clause. Thus, as a non-limiting example, in one embodiment, when used in conjunction with open-ended language such as “including,” a reference to “A and / or B” may refer only to A (optionally including elements other than B); in another embodiment, only to B (optionally including elements other than A); in yet another embodiment, both A and B (optionally including other elements); and so on.

[0071] As used herein in the specification and embodiments, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when items are listed in a list, “or” or “and / or” should be interpreted as inclusive, that is, including several elements or at least one of a list of elements, but also including more than one, and optionally including additional unlisted items. Only terms that explicitly indicate the opposite, such as “only one of” or “exactly one of” or, when used in embodiments, “consisting of”, will refer to including a number of elements or exactly one of a list of elements. In general, when preceded by an exclusive term such as “any one,” “one of,” “only one of,” or “exact one of,” the term “or” as used herein should be interpreted only to indicate an exclusive alternative (i.e., “one or another, not two”). When used in embodiments, “consisting substantially of” should have its ordinary meaning as used in the field of patent law.

[0072] As used herein in the specification and embodiments, the phrase "at least one" relating to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the element list, but does not necessarily include at least one of each element specifically listed in the element list, and does not exclude any combination of elements in the element list. This definition also allows for the optional presence of elements other than those specifically identified in the element list referred to by the phrase "at least one," whether related to or unrelated to those specifically identified elements. Thus, as a non-limiting vector, in one embodiment, "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") may refer to at least one, optionally including more than one A and not B (and optionally including elements other than B); in another embodiment, it refers to at least one, optionally including more than one B and not A (and optionally including elements other than A); in yet another embodiment, it refers to at least one, optionally including more than one A, and refers to at least one, optionally including more than one B (and optionally including other elements); and so on.

[0073] In the embodiments and in the above description, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “constituting,” etc., should be understood as open-ended, meaning including but not limited to. As set forth in Section 2111.03 of the U.S. Patent Examination Procedure Manual, only the transitional phrases “consisting of” and “consisting substantially of” are closed or semi-closed transitional phrases, respectively.

[0074] While specific embodiments of the present disclosure have been outlined above, many alternatives, modifications, and variations will be apparent to those skilled in the art. Therefore, the embodiments set forth herein are intended to be illustrative rather than restrictive. Various changes can be made without departing from the spirit and scope of the present disclosure. Where the foregoing methods and steps indicate specific events occurring in a particular order, those skilled in the art who benefit from the present disclosure will recognize that the order of particular steps can be modified, and such modifications are variations of the invention. Additionally, when possible, certain steps may be performed simultaneously in parallel processes, and in the order described above. Embodiments have been specifically shown and described; however, it should be understood that various changes in form and detail may be made.

Claims

1. A method of recycling battery scrap, the battery scrap comprising an electrode material and aluminum impurities, the method comprising: modifying the aluminum impurities to form a precursor; and incorporating the precursor into the electrode material.

2. The method of claim 1, further comprising: prior to modifying the aluminum impurities, pre-processing the battery scrap to separate the electrode material and the aluminum impurities from other components included in the battery scrap.

3. The method of claim 1, further comprising: prior to modifying the aluminum impurities, removing at least a portion of the aluminum impurities from the battery scrap.

4. The method of claim 3, wherein the aluminum impurities are physically removed from the battery scrap based on a difference in physical properties of the aluminum impurities.

5. The method of claim 4, wherein the aluminum impurities are removed from the battery scrap based on a difference in density.

6. The method of claim 3, wherein the aluminum impurities are chemically removed from the battery scrap.

7. The method of claim 6, wherein chemically removing the aluminum impurities comprises: dissolving the aluminum impurities in a hydroxide solution; and separating the electrode material from the hydroxide solution.

8. The method of claim 6, wherein the hydroxide solution comprises at least one of sodium hydroxide, potassium hydroxide, or lithium hydroxide.

9. The method of claim 6, wherein chemically removing the aluminum impurities comprises: dissolving the aluminum impurities in an acid solution; and separating the electrode material from the acid solution.

10. The method of claim 1, wherein the electrode material comprises at least one of LiCoO2, LiMn2O4, LiFe t M 1-t PO4, or LiNi a Mn b Co c A d O2. wherein: a + b + c + d = 1, 0 < t < 1， M comprises a metal element; and A = Al, Zr, or Mg.

11. The method of claim 10, wherein: the precursor comprises a doped precursor, the doped precursor comprising an aluminum atom; the electrode material comprises at least one of lithium or iron; and incorporating the doped precursor comprises inserting the aluminum atom into the electrode material at a site of at least one of a lithium atom or an iron atom.

12. The method of claim 11, wherein: inserting the aluminum atoms into the electrode material causes the electrode material to have a Li 1-3y Al y FePO4or LiFe 1- 1.5y Al y PO4composition.

13. The method of claim 1, further comprising: adding an additional precursor material during modifying the aluminum impurities.

14. The method of claim 13, wherein the additional precursor material comprises at least one of Li2CO3, LiOH, FePO4, or (NH4)2HPO4.

15. The method of claim 1, wherein: the precursor is a doped precursor; and modifying the aluminum impurities comprises converting the aluminum impurities into a metal layered double hydroxide compound as the doped precursor, the metal comprising at least one of lithium or aluminum.

16. The method of claim 15, wherein converting the aluminum impurities into the metal layered double hydroxide compound comprises reacting the aluminum impurities with an aqueous lithium hydroxide solution.

17. The method of claim 1, wherein: the precursor is a doped precursor; and the doped precursor comprises an aluminum atom. Modifying the aluminum impurities includes converting aluminum impurities into aluminum hydroxide (Al(OH)3) as the doping precursor.

18. The method of claim 17, wherein converting the aluminum impurities into aluminum hydroxide includes: reacting aluminum impurities with a hydroxide solution to form a mixture; and adjusting the pH of the mixture to form the aluminum hydroxide.

19. The method of claim 18, wherein adjusting the pH of the mixture includes adding at least one acid to the mixture.

20. The method of claim 18, wherein adjusting the pH of the mixture includes pumping carbon dioxide gas into the mixture.

21. The method of claim 1, wherein: the precursor is a doping precursor; and modifying the aluminum impurities includes converting aluminum impurities into an aluminum alkoxide (Al(RO)3) as a doping precursor, where R is an alkyl group.

22. The method of claim 21, wherein converting the aluminum impurities into an aluminum alkoxide includes: reacting the aluminum impurities with an organic compound comprising at least one hydroxyl (-OH) functional group.

23. The method of claim 1, wherein: the precursor includes a coating precursor; and modifying the aluminum impurities to form the coating precursor includes converting aluminum impurities into a LiAlO2 compound as the coating precursor.

24. The method of claim 1, wherein incorporating the precursor into the electrode material includes subjecting the precursor and the electrode material to a heat treatment process.

25. The method of claim 24, wherein heat treating is performed in a controlled atmosphere, the controlled atmosphere including an inert atmosphere, an oxidizing atmosphere, or a reducing atmosphere.

26. A method of regenerating an electrode material, the method comprising: obtaining a battery waste, the battery waste comprising the electrode material and aluminum impurities; and regenerating the electrode material by incorporating at least a portion of the aluminum impurities into the electrode material.

27. The method of claim 26, wherein the electrode material is incorporated with at least a portion of the aluminum impurities via a mixer or a mechanical fusion device.

28. The method of claim 26, further comprising: prior to regenerating the electrode material, modifying the aluminum impurities into a precursor, wherein the electrode material is regenerated by at least one of doping or coating the electrode material with the precursor.

29. The method of claim 26, wherein the electrode material is regenerated at a temperature of at least 400 degrees Celsius.

30. The method of claim 26, wherein regenerating the electrode material includes mixing the electrode material with a lithium source.

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