Compositions and methods for recycling lithium-ion battery materials

Abstract

Described to compositions and methods for recycling lithium-ion battery materials. More specifically, described herein to acid- and base-free compositions and methods for the recovery of lithium and other valuable materials such as Ni, Co, Mn, Cu, Al, graphite, etc. from lithium-containing battery materials for subsequent purification and reuse. Certain methods described herein for recovering lithium from a lithium-ion battery comprise isolating a bulk material from a cathode or the cathode and an anode of a lithium-ion battery, the bulk material comprising lithium, reacting the bulk material with a persulfate compound to form lithium sulfate or a hydrate thereof, and recovering the lithium sulfate or the hydrate thereof.

Description

COMPOSITIONS AND METHODS FOR RECYCLING LITHIUM-ION BATTERYMATERIALSCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional No. 63 / 532,986 filed August 16,2023, the entire contents of which are incorporated by reference herein.FIELD OF THE INVENTION

[0002] The present invention relates to compositions and methods for recycling lithium-ion battery materials. More specifically, the present invention relates to acid- and base-free compositions and methods for the recovery of lithium and other valuable materials such as Ni, Co, Mn, Cu, Al, graphite, etc. from lithium-containing battery materials for subsequent purification and reuse.BACKGROUND OF THE DISCLOSURE

[0003] Over time, the demand for lithium for use in lithium-ion batteries has experienced rapid growth in various market sectors such as electric cars, portable electronics, and renewable energy storage devices, to name a few. Lithium-ion batteries (LIBs) are widely used and desirable because of their high volumetric energy densities (320-450 Wh L'1), power ouput (over 300 W kg'1) and high cycling stability- (2000 cycles without decreasing). Between 2016 and 2020, global lithium production more than doubled from 38,000 metric tons to 82.000 metric tons. During the same period of time, electric vehicles sales increased by from about 750,000 to about 2,900,000. The substantial increase in lithium-ion battery production in recent years has accelerated the consumption of the raw materials worldwide. Meanwhile, the limited availability of earth reserves for materials such as Li, Co, and Ni has posed significant sustainability challenges for energy storage development, such as batteries.

[0004] Some estimates reported that less than 25% of the spent recyclable batteries are recycled and less than 2% of lithium from spent lithium-ion batteries were recycled worldwide in 2020. The finite lifetime of lithium-ion batteries, coupled with the low recycling rates, continues to increase waste management burdens of spent batteries. Some predict that, in the next 20 years, waste related to LIBs with will reach 4 million metric tons. The accumulation of LIBs waste can cause great harm to the environment due to the release of metal ions, fluorides and electrolytes. Recycling spent LIBs is imperative to protect the environment and recover valuable metal resources.

[0005] Pyrometallurgy and hydrometallurgy are currently considered primary' routes for recycling lithium-ion batteries. Pyrometallurgical methods smelt spent batteries directly and recover metals. Pyrometallurgical methods provide some advantages including short process flow, high recovery rates, simple equipment and strong operability. This technology' is the most common recycling method in LIB recycling plants. However, pyrometallurgical methods require high energy inputs (heat treatment at temperatures above 1000 °C), can be responsible for severe air pollution, the product outputs exhibit low purity and the products are metal alloys which cannot be recovered individually.

[0006] Hydrometallurgical methods are generally more flexible in using various chemical reagents to leach metals, followed by extraction and purification. In hydrometallurgical methods metal oxides, metal hydroxides, and metal carbonates of a spent battery re solubilized using strong acids or strong bases, followed by separate precipitation of the individual metal salts according to their solubility'. However, the problems are needing strong acids / bases, elements separating with similar properties, high consumption of water and chemical reagents, complex equipment requirements and high cost of pollution treatment.

[0007] These processes and associated disposal issues present numerous problems for those in the field of battery recycling.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a flowchart illustrating an exemplary method for bulk recovery of active materials from a spent lithium-ion battery in accordance with various aspects of the disclosure.

[0009] FIG. 2 is a flowchart illustrating an exemplary' method for recovering individual materials (such as lithium and cobalt) from the bulk active materials recovered in an exemplary method as illustrated in FIG. 1 in accordance with various aspects of the disclosure.

[0010] FIG. 3 is a flowchart illustrating another exemplary' method for bulk recovery of active materials from a spent lithium-ion battery in accordance with various aspects of the disclosure.

[0011] FIG. 4 is a flowchart illustrating an exemplary method for recovering individual materials (in the form of a metal sulfate salts solution) from the bulk active materials recovered in an exemplary method as illustrated in FIG. 3 in accordance with various aspects of the disclosure.

[0012] FIG. 5 is a flowchart illustrating an exemplary method for recovering individual materials (in the form of metal oxides or metal hydroxides, and lithium carbonate) from metal sulfate salts recovered in an exemplary' method as illustrated in FIG. 4 in accordance with various aspects of the disclosure.

[0013] FIG. 6 is a Powder X-Ray Diffraction (PXRD) pattern of a milled and sintered sampleproduced in Example 1.

[0014] FIG. 7 is a PXRD patern of a dried raffinate solution obtained in Example 1.

[0015] FIG. 8 is a PXRD patern of CO3O4 obtained in Example 1.

[0016] FIG. 9 is an XPS patern showing the elemental composition of the extractive materials of Example 1.

[0017] FIG. 10 provides a graphical overview of the advantages and shortcomings of prior art methods for the recoven’ of lithium and other metals of interest from spent lithium-ion bateries.DETAILED DESCRIPTION

[0018] The following description of the embodiments is merely exemplary in nature and is in no way intended to limit the subject mater of the present disclosure, their application, or uses.

[0019] As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight.

[0020] For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” The use of the term “about” applies to all numeric values, whether or not explicitly indicated. This term generally refers to a range of numbers that one of ordinary skill in the art would consider as a reasonable amount of deviation to the recited numeric values (i.e., having the equivalent function or result). For example, this term can be construed as including a deviation of ±20 percent, ±10 percent, alternatively ±5 percent, alternatively ±1 percent, alternatively ±0.5 percent, and alternatively ±0. 1 percent of the given numeric value provided such a deviation does not alter the end function or result of the value. Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and atached claims are approximations that can vary’ depending upon the desired properties sought to be obtained by the present invention.

[0021] It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an.” and “the,” include plural references unless expressly and unequivocally limited to one referent. As used herein, the term “include” and its grammatical variants are intended to be nonlimiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items. For example, as used in this specification and the following claims, the terms “comprise” (as well as forms, derivatives, or variations thereof, such as “comprising” and “comprises”), “include” (as well as forms, derivatives, or variations thereof, suchas “including” and “includes”) and “has” (as well as forms, derivatives, or variations thereof, such as “having” and “have”) are inclusive (i.e., open-ended) and do not exclude additional elements or steps. Accordingly, these terms are intended to not only cover the recited element(s) or step(s), but may also include other elements or steps not expressly recited. Furthermore, as used herein, the use of the terms “a” or “an” when used in conjunction with an element may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” Therefore, an element preceded by “a” or “an” does not, without more constraints, preclude the existence of additional identical elements.

[0022] FIGS. 1 and 2 are flowcharts illustrating an exemplary method for recovering metals of interest, such as lithium and cobalt, from a spent (or used) lithium-ion battery'. More specifically, FIG. l is a flowchart illustrating an exemplary method for the bulk recovery of active metals from a spent lithium-ion batter}' in accordance with various aspects of the disclosure, and FIG. 2 is a flowchart illustrating an exemplar}' method for recovering individual active materials (such as lithium and cobalt) from the bulk active materials recovered in an exemplary method as illustrated in FIG. 1 in accordance with various aspects of the disclosure. In some instances, one or more steps may be added or removed from the exemplary method without departing from the scope of this disclosure. An exemplary method according to various aspects of the disclosure can begin at step 105.

[0023] In step 105, a spent lithium-ion battery is provided. The type of spent lithium-ion battery is not to be used in the exemplary is not particularly limiting. In some instances, the lithium ion battery can be, for example, a coin cell battery, a pouch cell battery, a batter}' from a portable electronic device (such as a smartphone, tablet, laptop, wireless speaker, and so on), a lithium ion automobile battery, and so on. Furthermore, the composition of the lithium-ion batter}' is not particularly limiting. Suitable compositions of lithium-ion batteries can include, but are not necessarily limited to, lithium-ion cobalt oxide batteries, lithium-silicon batteries, lithium-ion manganese iron phosphate batteries, lithium-ion manganese-oxide batteries, lithium-ion polymer batteries, lithium-iron-phosphate batteries, lithium-nickel-manganese-cobalt oxides batteries, lithium-nickel-cobalt-aluminum oxides batteries, lithium-sulfur batteries, lithium-selenium batteries, lithium-sulfur / selenium batteries, lithium-nickel oxide batteries, lithium-manganese oxide batteries, lithium iron phosphate batteries, and lithium-titanate batteries. In some instances, as illustrated in exemplar ’ method steps below, lithium-ion batteries comprising at least lithium and cobalt may be preferred. In other instances, lithium-ion batteries comprising at least lithium, cobalt and nickel may be preferred. In other instances, lithium-ion batteries comprising at least lithium, cobalt, nickel, and manganese may be preferred. In other instances, lithium-ion batteriescomprising at least lithium, cobalt, nickel, and aluminum may be preferred.

[0024] In step 110. the spent lithium-ion batten’ is discharged after disabling overcharge protection. Generally, the method by which the batten' is discharged is not particularly limiting. In some instances, the battery can be discharged by, for example immersing the anode and the cathode of the battery in an aqueous sodium chloride solution.

[0025] In step 115, the discharged battery is dismantled (or disassembled). The dismantled battery is then immersed in water including a deionized (DI) water bath and allowed to soak in the water bath for a period of time sufficient to allow' for the anode and the cathode / separator to isolated from each other. In general, the length of the soak period may depend on various parameters such as the size and / or surface area of the dismantled battery and the composition of the battery'. In some instances, the soak period may range from about 15 minutes to about 8 hours, alternatively from about 30 minutes to about 6 hours, alternatively from about 45 minutes to about 4 hours, alternatively from about 1 hour to about 3 hours, and alternatively from about 1.5 hours to about 2.5 hours. In some instances, the soak period can be about 2 hours. The temperature of the water bath can range from room temperature (20-22 °C) to about 100 °C.

[0026] In step 120, after completion of the soak period, the anode is removed from the water bath and isolated, and the cathode / separator is removed from the water bath and isolated.

[0027] In step 125, the isolated anode is then immersed in a second water bath and allowed to soak in the second w ater bath for a period of time sufficient to facilitate separation of individual components of the anode (such as carbon-based materials (e.g.. graphite, activated carbon, carbon black, carbon nanotubes, etc.), copper foil, platinum, zinc, iron, ceramics and so on) and the subsequent isolation and recovery of the individual anode components in step 130. In general, the length of the second w ater bath soak period may depend on various parameters such as the size and / or surface area of the anode and the composition of the anode. In some instances, the second w ater bath soak period may range from about 1 hour to about 24 hours, alternatively from about 2 hours to about 20 hours, alternatively from about 3 hours to about 16 hours, alternatively from about 4 hours to about 12 hours, alternatively from about 6 hours to about 10 hours, and alternatively from about 7 hours to about 9 hours. In some instances, the second water bath soak period can be about 8 hours. The temperature of the second water bath can range from room temperature (20-22 °C) to about 100 °C. In some instances, the temperature of the second water bath can range from about 30 °C to about 100 °C, alternatively from about 40 °C to about 100 °C, alternatively from about 50 °C to about 100 °C, alternatively from about 60 °C to about 100 °C, alternatively from about 70 °C to about 100 °C, alternatively from about 80 °C to about 100 °C, and alternatively from about 90 °C to about 100 °C. In some instances, the temperature of thesecond water bath can be about 100 °C. At the end of step 125, individual components of the anode (such as carbon-based materials (e.g., graphite, activated carbon, carbon black, carbon nanotubes, etc.), copper foil, platinum, zinc, iron, ceramics and so on) can be subjected to additional separation and purification steps, and the purified individual components can be recycled for future use in new batteries or other applications.

[0028] In step 135, the isolated cathode / separator is then immersed in a third water bath and allowed to soak in the third water bath for a period of time sufficient to facilitate separation of the cathode material from the battery separator. In general, the length of the third water bath soak period may depend on various parameters such as the size and / or surface area of the cathode and battery separator and the compositions of the cathode material and battery separator. In some instances, the third water bath soak period may range from about 1 hour to about 24 hours, alternatively from about 2 hours to about 20 hours, alternatively from about 3 hours to about 16 hours, alternatively from about 4 hours to about 12 hours, alternatively from about 5 hours to about 10 hours, and alternatively from about 5 hours to about 9 hours. In some instances, the third water bath soak period can be about 8 hours. The temperature of the third water bath can range from room temperature (20-22 °C) to about 100 °C. In some instances, the temperature of the third water bath can range from about 30 °C to about 100 °C, alternatively from about 40 °C to about 100 °C, alternatively from about 50 °C to about 100 °C, alternatively from about 60 °C to about 100 °C, alternatively from about 70 °C to about 100 °C, alternatively from about 80 °C to about 100 °C, and alternatively from about 90 °C to about 100 °C. In some instances, the temperature of the third water bath can be about 100 °C.

[0029] In step 140, the separator is separated (by, e.g., peeling) from the cathode material, which comprises active materials (such as lithium cobalt, nickel, and so on) and a metal foil (for example, an aluminum foil), and the third water bath. At the conclusion of step 140, the cathode material, now isolated from the battery separator, remains in the third water bath for further processing.

[0030] In step 145, the isolated cathode material is then allowed to continue to soak in the third DI water bath for a period of time sufficient to facilitate separation of active materials from the metal foil. In some instances, the continued water bath soak period in this step may range from about 15 minutes to about 8 hours, alternatively from about 30 minutes to about 6 hours, alternatively from about 45 minutes to about 4 hours, alternatively from about 1 hour to about 3 hours, and alternatively from about 1.5 hours to about 2.5 hours. In some instances, the soak period can be about 2 hours. The temperature of the water bath during the soak period in this step can range from room temperature (20-22 °C) to about 100 °C. In some instances, separation of active materials from the metal foil during the soak period of this step can further be facilitated with theaid of agitation. In some instances, the agitation can be in the form of stirring with the aid of a mechanical stirring means such as, for example, a magnetic stir bar or a paddle mixer. In some instances, the agitation can be in the form of direct or indirect sonication using, for example, an ultrasonic bath, an ultrasonic probe or an ultrasonic hom. In general, the length of the fourth water bath soak period may depend on various parameters such as the size and / or surface area of the cathode and battery separator and the compositions of the cathode and battery separator, the temperature of the water bath and the type and / or intensity of agitation. At the end of step 145. the metal foil can be recovered, purified and recycled for future use in new batteries or other applications.

[0031] In step 150, the active materials, now removed from the metal foil are isolated and dried. At the end of step 150. a dried mixture of bulk active materials (such as lithium cobalt, nickel, and so on) is produced. Upon completion of step 150, the exemplary method proceeds with steps toward recovery individual active materials of interest from the dried bulk active materials as illustrated in FIG. 2.

[0032] In step 205, the dried bulk active materials are provided. The dried bulk active materials are then mixed with an extraction reagent in step 210. Generally, any mixing technique that results in a homogenous or substantially homogenous mixture is sufficient. In some instances, ball milling is a preferred technique for mixing the dried bulk active materials and the extraction reagent. In some instances, the mixing may be conducted for a period of time ranging from about 15 minutes to about 8 hours, alternatively from about 30 minutes to about 6 hours, alternatively from about 45 minutes to about 4 hours, alternatively from about 1 hour to about 3 hours, and alternatively from about 1.5 hours to about 2.5 hours. In some instances, the mixing may be conducted for a period of time of about 2 hours. In some instances, the extraction reagent is a persulfate (S20s2') salt. In some instances, the persulfate salt comprises an organic cation. In some instances, it is preferable that the persulfate salt comprises an organic cation that will volatize during a baking process (step 215, below). Suitable persulfates (also commonly referred to as peroxy disulfates and peroxodisulfates) include, but are not limited to, peroxydisulfuric acid, sodium persulfate, potassium persulfate, calcium persulfate, bis(tetrabutylammonium) peroxydisulfate, benzyltriphenylphosphonium peroxy disulfate, choline peroxy disulfate, ammonium persulfate and combinations thereof. In some instances, the use of ammonium persulfate as the extraction reagent is preferred. In some instances, the extraction reagent is added to the mixture in a stoichiometric amount relative to the combined molar amount of active materials of interest (for example, lithium, cobalt, nickel, and so on) that are to ultimately be recovered from the dried bulk active materials (step 240, below). In some instances, the extraction reagent is added to the mixture in astoichiometric excess relative to the combined molar amount of active materials of interest that are to ultimately be recovered from the dried bulk active materials. In some instances, the extraction reagent is added to the mixture in an amount that results in the mixture having a dried bulk active materials-to-extraction reagent weightweight ratio ranging from about 5: 1 to about 1:5, alternatively from about 4: 1 to about 1 :4, alternatively from about 3: 1 to about 1:3, alternatively from about 2: 1 to about 1:2, and alternatively about 1 : 1.

[0033] In step 215, the mixture of the dried bulk active matenals and the extraction reagent are sintered (or baked) to formed a sintered composition. During the sintering process, the bulk active materials react with the extraction reagent to form corresponding sulfates salts and / or oxides. Sintering can be conducted at a temperature ranging from about 150 °C to about 700 °C, alternatively from about 200 °C to about 650 °C, alternatively from about 300 °C to about 600 °C, alternatively from about 400 °C to about 550 °C, alternatively from about 450 °C to about 550 °C, and alternatively from about 475 °C to about 525 °C. In some instances, the sintering temperature can be about 500 °C. Sintering can be conducted for a period of time ranging from about 15 minutes to about 4 hours, alternatively from about 15 minutes to about 3 hours, alternatively from about 15 minutes to about 2 hours, and alternatively from about 15 minutes to about 1 hour. In some instances, sintering can be conducted under atmospheric pressure. In some instances, sintering can be conducted in at a pressure less than atmospheric pressure, such as anywhere from 0.01 to 0.99 atm. In some instances, sintering can be conducted in at a pressure greater atmospheric pressure, such as anywhere from 1.01 to about 10 atm. In some instances, sintering can be conducted in an inert gas such as nitrogen or argon. In some instances, sintering can be conducted in a state environment of the inert gas. In some instances, sintering can be conducted under a flow of the inert gas.

[0034] In step 220, the sintered mixture is dispersed in water for a period of time sufficient for sulfate salts of the active materials, and other water-soluble active material-containing compounds formed during sintering in step 215, to completely of substantially completely leach from the sintered composition into the DI water. Upon the completion of step 220, a dispersion comprising metal oxide solids dispersed in an aqueous active material(s) sulfate salt(s) solution is formed.

[0035] In step 225, the dispersion is filtered, a raffinate (the aqueous active material(s) sulfate salt(s) solution) is recovered in step 230, and a filtrate (the insoluble metal oxide solids) is recovered in step 250.

[0036] In step 235, the raffinate is heated to evaporate the water solvent and the final active material(s) sulfate salt(s) of interest (for example, sulfate salts of lithium and cobalt) is / are recovered in step 240. The final active material(s) sulfate salt(s) of interest can subsequently befurther purified, if necessary, and recycled for future use in new batteries or other applications.

[0037] In step 255, the filtrate is sintered (or baked) to volatize or combust organic end products, such as carbon, leaving end products comprising a metal or metals of interest, such as metal oxides, to be recovered in step 260. The end products comprising the metal or metals of interest can subsequently be further purified, if necessary7, and recycled for future use in new batteries or other applications.

[0038] FIGS. 3-5 are flowcharts illustrating various exemplary methods for recovering metals of interest, such as lithium, cobalt nickel and manganese, from a spent (or used) lithium-ion battery. FIG. 3 is a flowchart illustrating another exemplary7method for bulk recovery7of active materials from a spent lithium-ion battery in accordance with various aspects of the disclosure. FIG. 4 is a flowchart illustrating an exemplary method for recovering individual materials (in the form of a metal sulfate salts solution) from the bulk active materials recovered in an exemplary method as illustrated in FIG. 3 in accordance with various aspects of the disclosure. FIG. 5 is a flowchart illustrating an exemplary7method for recovering individual materials (in the form of metal oxides or metal hydroxides, and lithium carbonate) from metal sulfate salts recovered in an exemplary method as illustrated in FIG. 4 in accordance with various aspects of the disclosure. In some instances, one or more steps may be added or removed from the exemplary method without departing from the scope of this disclosure.

[0039] Exemplary methods according to various aspects of the disclosure as illustrated in FIGS. 3-5 utilize extraction reagent. As described elsewhere herein, in some instances, the extraction reagent is a persulfate (S20s2’) salt. In some instances, the persulfate salt comprises an organic cation. In some instances, it is preferable that the persulfate salt comprises an organic cation that will volatize during a baking process (step 215, below). Suitable persulfates (also commonly referred to as peroxydisulfates and peroxodisulfates) include, but are not limited to, peroxydisulfuric acid, sodium persulfate, potassium persulfate, calcium persulfate, bis(tetrabutylammonium) peroxydisulfate, benzyltriphenylphosphonium peroxy di sulfate, choline peroxy disulfate, ammonium persulfate and combinations thereof. In some instances, the use of ammonium persulfate as the extraction reagent is preferred.

[0040] Certain exemplary methods according to various aspects of the disclosure as illustrated in FIGS. 3-5 utilize hydrogen peroxide in addition to the extraction reagent. The hydrogen peroxide may be provided in the form of an aqueous solution containing, for example 20 to 40 %, alternatively 20 to 35 %, or alternatively 25 to 30 % hydrogen peroxide.

[0041] Exemplary methods according to various aspects of the disclosure as illustrated in FIGS. 3-5 can begin at step 305.

[0042] In step 305, a spent lithium-ion battery is provided. The type of spent lithium-ion battery is not to be used in the exemplary is not particularly limiting. In some instances, the lithium ion battery can be, for example, a coin cell battery, a pouch cell battery, a battery from a portable electronic device (such as a smartphone, tablet, laptop, wireless speaker, and so on), a lithium ion automobile battery, and so on. Furthermore, the composition of the lithium-ion battery is not particularly limiting. Suitable compositions of lithium-ion batteries can include, but are not necessarily limited to, lithium-ion cobalt oxide batteries, lithium-silicon batteries, lithium-ion manganese iron phosphate batteries, lithium-ion manganese-oxide batteries, lithium-ion polymer batteries, lithium-iron-phosphate batteries, lithium-nickel-manganese-cobalt oxides batteries, lithium-nickel-cobalt-aluminum oxides batteries, lithium-sulfur batteries, lithium-selenium batteries, lithium-sulfur / selenium batteries, lithium-nickel oxide batteries, lithium-manganese oxide batteries, lithium iron phosphate batteries, and lithium-titanate batteries. In some instances, as illustrated in exemplary method steps below, lithium-ion batteries comprising at least lithium and cobalt may be preferred. In other instances, lithium-ion batteries comprising at least lithium, cobalt and nickel may be preferred. In other instances, lithium-ion batteries comprising at least lithium, cobalt, nickel, and manganese may be preferred. In other instances, lithium-ion batteries comprising at least lithium, cobalt, nickel, and aluminum may be preferred.

[0043] In step 310, the spent lithium-ion battery is discharged after disabling overcharge protection. Generally, the method by which the battery is discharged is not particularly limiting. In some instances, the battery can be discharged by, for example immersing the anode and the cathode of the battery in an aqueous sodium chloride solution.

[0044] In step 315, the discharged battery is dismantled (or disassembled) remove the battery separator from the anode and cathode materials.

[0045] In step 320, the anode and cathode materials are subjected to a thermal treatment to volatize and remove additives contained within the materials such a binders. In some instances, the thermal treatment can be conducted at a temperature ranging from about 100 °C to about 300 °C, alternatively from about 120 °C to about 250 °C, alternatively from about 140 °C to about 225 °C, alternatively from about 160 °C to about 200 °C, and alternatively from about 170 °C to about 190 °C. In some instances, the thermal treatment can be conducted at a temperature of about 180 °C. In some instances, the thermal treatment can be conducted for a period of time ranging from about 15 minutes to about 4 hours, alternatively from about 15 minutes to about 3 hours, alternatively from about 15 minutes to about 2 hours, alternatively from about 15 minutes to about 1 hour, and alternatively about 30 minutes. As one of ordinary skill in the art may appreciate, the thermal treatment time and temperature may vary on the composition and amount of additives tobe removed from the anode and cathode materials during the thermal treatment.

[0046] In step 325, the thermally treated anode and cathode materials are subj ected are immersed in DI water and subjected to sonication for a period of time sufficient to separate the active metals from charge collectors (i.e., copper and aluminum foils) of the anode and cathode materials. The sonication can be in the form of direct or indirect sonication using, for example, an ultrasonic bath, an ultrasonic probe or an ultrasonic hom. In some instances, the sonication period in this step may range from about 1 minute to about 1 hour, alternatively from about 5 minutes to about 45 minutes, alternatively from about 10 minutes to about 30 minutes, alternatively from about 10 minutes to about 15 minutes, and alternatively about 15 minutes.

[0047] In step 330, the charge collectors are removed from the sonicated solution leaving an aqueous solution of the active materials (e.g., Li, Co, Ni, Mn, and so on depending on the battery composition).

[0048] In step 335, the aqueous solution of the active materials is heated to evaporate the water and result in a dried mixture of bulk active materials. The dried mixture of bulk active materials, based on physical appearance, may be referred to a black mass. Upon completion of step 335, the exemplary method proceeds with steps toward recovery individual active materials of interest (in the form of a metal sulfate salts solution) from the dried bulk active materials, or black mass, as illustrated in FIG. 4.

[0049] FIG. 4 illustrates four separate exemplary pathways for converting the dried bulk active materials, or black mass, to solution comprising sulfate salts of the metals of interest. Each of the four exemplar}' pathways may end in a filtration step 450 to recover a raffinate 455 comprising a solution comprising sulfate salts of the metals of interest and a filtrate 460 comprising carbonaceous materials, such a graphite, of the original anode and cathode materials.

[0050] In a first exemplary pathway, dried bulk active materials provided in step 405 are mixed with an extraction reagent and then sintered (or baked) in step 410. In this exemplary pathway, mixing can be performed using, for example, a ball mill for a period of time ranging from about 30 minutes to about 4 hours, alternatively from about 1 hour to about 3 hours, and alternatively about 2 hours. The dry’ active materials and extraction agent can be mixed in a dried bulk active materials-to-extraction reagent weightweight ratio ranging from about 5: 1 to about 1:5. alternatively from about 4: 1 to about 1 :4, alternatively from about 3: 1 to about 1:3, alternatively from about 2: 1 to about 1:2, and alternatively about 1: 1. During the sintering process, the bulk active materials react with the extraction reagent to form corresponding sulfates salts and / or oxides. Sintering can be conducted at a temperature ranging from about 150 °C to about 700 °C, alternatively from about 200 °C to about 650 °C, alternatively from about 300 °C to about 600 °C,alternatively from about 400 °C to about 550 °C, alternatively from about 450 °C to about 550 °C, and alternatively from about 475 °C to about 525 °C. In some instances, the sintering temperature can be about 500 °C. Sintering can be conducted for a period of time ranging from about 15 minutes to about 4 hours, alternatively from about 15 minutes to about 3 hours, alternatively from about 15 minutes to about 2 hours, and alternatively from about 15 minutes to about 1 hour. In some instances, sintering can be conducted under atmospheric pressure. In some instances, sintering can be conducted in at a pressure less than atmospheric pressure, such as anywhere from 0.01 to 0.99 atm. In some instances, sintering can be conducted in at a pressure greater atmospheric pressure, such as anywhere from 1.01 to about 10 atm. In some instances, sintering can be conducted in an inert gas such as nitrogen or argon. In some instances, sintering can be conducted in a static environment of the inert gas. In some instances, sintering can be conducted under a flow of the inert gas.

[0051] In step 415, the sintered mixture is dispersed in water for a period of time sufficient for sulfate salts of the active materials, and other water-soluble active material-containing compounds formed during step 410, to completely of substantially completely leach from the sintered composition into the water. In some instances, the sintered mixture can be dispersed in a water at a sintered mixture-to-water weight: weight ratio of 1 : 10. The relative amounts of water and sintered mixture used in step 415 can be modified as necessary to maximize the leaching process. The dispersion formed in step 415 is then subjected to filtration in step 450 as discussed above for recovery of raffinate 455 and filtrate 460.

[0052] In a second exemplary pathway, dry active materials provided in step 405 are mixed with an extraction reagent and then sintered (or baked) in step 420. In this exemplary pathway, mixing can be performed using, for example, mechanical vibration for a period of time ranging from about 1 minute to about 1 hour, alternatively from about 5 minutes to about 30 minutes, alternatively from about 5 minutes to about 15 minutes, and alternatively about 10 minutes. The dry active materials and extraction agent can be mixed in a dried bulk active materials-to-extraction reagent weight: weight ratio ranging from about 5: 1 to about 1:5, alternatively from about 4: 1 to about 1:4, alternatively from about 3: 1 to about 1:3, alternatively from about 2: 1 to about 1:2, and alternatively about 1: 1. During the sintering process, the bulk active materials react with the extraction reagent to form corresponding sulfates salts and / or oxides. Sintering can be conducted at a temperature ranging from about 150 °C to about 700 °C, alternatively from about 200 °C to about 650 °C, alternatively from about 300 °C to about 600 °C, alternatively from about 400 °C to about 550 °C, alternatively from about 450 °C to about 550 °C, and alternatively from about 475 °C to about 525 °C. In some instances, the sintering temperature can be about 500 °C. Sinteringcan be conducted for a period of time ranging from about 15 minutes to about 4 hours, alternatively from about 15 minutes to about 3 hours, alternatively from about 15 minutes to about 2 hours, and alternatively from about 15 minutes to about 1 hour. In some instances, sintering can be conducted under atmospheric pressure. In some instances, sintering can be conducted in at a pressure less than atmospheric pressure, such as anywhere from 0.01 to 0.99 atm. In some instances, sintering can be conducted in at a pressure greater atmospheric pressure, such as anywhere from 1.01 to about 10 atm. In some instances, sintering can be conducted in an inert gas such as nitrogen or argon. In some instances, sintering can be conducted in a static environment of the inert gas. In some instances, sintering can be conducted under a flow of the inert gas.

[0053] In step 425, the sintered mixture is blended vigorously in an aqueous extraction reagent / FbCh solution. At the beginning of blending, the sintered mixture preferably has a temperature ranging from about 220 °C to about 300 °C. The blending process is conducted for a period of time sufficient for sulfate salts of the active materials, and other water-soluble active material-containing compounds formed during step 420, to completely of substantially completely leach from the sintered composition into the aqueous extraction reagent / FbCh solution. In some instances, the blending process is conducted for a period of time ranging from about 15 minutes to about 4 hours, alternatively from about 15 minutes to about 3 hours, alternatively from about 15 minutes to about 2 hours, and alternatively from about 15 minutes to about 1 hour In some instances, the sintered mixture can be dispersed in a aqueous extraction reagent / tbCh solution having an extraction reagent-to-H2O2 weight: weight ratio of about 1: 10. The relative amounts of water and sintered mixture used in step 425 can be modified as necessary to maximize the leaching process. The reaction solution of step 425 is then subjected to filtration in step 450 as discussed above for recovery of raffinate 455 and filtrate 460.

[0054] In a third exemplary pathway, dry active materials provided in step 405 are sintered (or baked) and then subjected to ball milling in step 430. In this exemplary pathway, the sintering can be conducted at a temperature ranging from about 100 °C to about 300 °C, alternatively from about 150 °C to about 275 °C, alternatively from about 175 °C to about 250 °C, and alternatively from about 200 °C to about 250 °C. In some instances, the sintering temperature can be about 220 °C. Sintenng can be conducted for a period of time ranging from about 15 minutes to about 4 hours, alternatively from about 15 minutes to about 3 hours, alternatively from about 15 minutes to about 2 hours, and alternatively from about 15 minutes to about 1 hour. In some instances, sintering can be conducted under atmospheric pressure. In some instances, sintering can be conducted in at a pressure less than atmospheric pressure, such as anywhere from 0.01 to 0.99 atm. In some instances, sintering can be conducted in at a pressure greater atmospheric pressure, such asanywhere from 1.01 to about 10 atm. In some instances, sintering can be conducted in an inert gas such as nitrogen or argon. In some instances, sintering can be conducted in a static environment of the inert gas. In some instances, sintering can be conducted under a flow of the inert gas. In this exemplary pathway, the ball milling process can be conducted for a period of time ranging from about 15 minutes to about 4 hours, alternatively from about 30 minutes to about 2 hours, and alternatively about 1 hour.

[0055] In step 435, the sintered and milled product of step 430 is blended with an aqueous extraction reagent solution. Then, an aqueous solution of H2O2 is slowly added and the resulting mixture stirred for period of time ranging from about 15 minutes to about 4 hours, alternatively from about 30 minutes to about 3 hours, alternatively from about 30 minutes to about 2 hours, and alternatively for about 1 hour. In step 435, the extraction reagent and sintered and milled product (step 430) are added in amounts that provide an extraction reagent-to-dry active materials mass ratio ranging from about 10: 1 to about 1: 1, alternatively from about 8: 1 to about 1:1, alternatively from about 6: 1 to about 1: 1, alternatively from about 4 : 1 to about 1:1, alternatively from about 3 : 1 to about 1: 1, alternatively from about 3: 1 to about 2: 1, and alternatively from about 2.5: 1 to about 2.3: 1. Also in step 435, the extraction reagent and H2O2 are used in amounts that provide a mass (g) of extraction reagent to volume (ml) of H2O2 ratio ranging from about 1 : 1 to about 1 :5, alternatively from about 1: 1 to about 1 :4, alternatively from about 1: 1 to about 1:3, alternatively from about 1 : 1.5 to about 1:2.5, and alternatively about 1:2. Upon completion of step 435, the resulting reaction solution is then subjected to filtration in step 450 as discussed above for recovery of raffinate 455 and filtrate 460.

[0056] In a fourth exemplary pathway, dry active materials provided in step 405 are sintered (or baked) in step 440. In this exemplary pathway, the sintering can be conducted at a temperature ranging from about 100 °C to about 300 °C. alternatively from about 150 °C to about 275 °C, alternatively from about 175 °C to about 250 °C, and alternatively from about 200 °C to about 250 °C. In some instances, the sintering temperature can be about 220 °C. Sintering can be conducted for a period of time ranging from about 15 minutes to about 4 hours, alternatively from about 15 minutes to about 3 hours, alternatively from about 15 minutes to about 2 hours, and alternatively from about 15 minutes to about 1 hour. In some instances, sintering can be conducted under atmospheric pressure. In some instances, sintering can be conducted in at a pressure less than atmospheric pressure, such as anywhere from 0.01 to 0.99 atm. In some instances, sintering can be conducted in at a pressure greater atmospheric pressure, such as anywhere from 1.01 to about 10 atm. In some instances, sintering can be conducted in an inert gas such as nitrogen or argon. In some instances, sintering can be conducted in a static environment of the inert gas.

[0057] In step 445. the sintered mixture is blended vigorously in an aqueous extraction reagent / H2O2 solution. At the beginning of blending, the sintered mixture preferably has a temperature ranging from about 180 °C to about 300 °C, even more preferably about 200 °C to about 240 °C, and in some instances about 220 °C. The blending process is conducted for a period of time sufficient for sulfate salts of the active materials, and other water-soluble active materialcontaining compounds formed during step 440, to completely of substantially completely leach from the sintered composition into the aqueous extraction reagent / FbCh solution. In some instances, the blending is performed for period of time ranging from about 15 minutes to about 4 hours, alternatively from about 30 minutes to about 3 hours, alternatively from about 30 minutes to about 2 hours, and alternatively for about 1 hour. In step 445, the extraction reagent and sintered and sintered mixture (step 440) are added in amounts that provide an extraction reagent-to-dry active materials mass ratio ranging from about 1 : 1 to about 10: 1, alternatively from about 1 : 1 to about 9: 1, alternatively from about 1: 1 to about 8:1, alternatively from about 1 : 1 to about 7: 1, and alternatively from about 1: 1 to about 6: 1. Also in step 445, the extraction reagent and FhCh are used in amounts that provide a mass (g) of extraction reagent to volume (ml) of H2O2 ratio ranging from about 1 : 1 to about 1:5, alternatively from about 1 : 1 to about 1:4, alternatively from about 1 : 1 to about 1:3, alternatively from about 1: 1.5 to about 1 :2.5, and alternatively about 1:2.

[0058] Upon completion of step 445 is then subjected to filtration in step 450 as discussed above for recovery of raffinate 455 and filtrate 460.

[0059] FIG. 5 is a flowchart illustrating an exemplary method for recovering individual materials (in the form of metal oxides or metal hydroxides, and lithium carbonate) from metal sulfate salts recovered as raffinate 455 in an exemplary method as illustrated in FIG. 4 in accordance with various aspects of the disclosure. As illustrated in FIG. 5, two exemplary pathways may be taken to recover lithium, in the form of lithium carbonate, and other metals of interest in the form of metal oxides or metal hydroxides.

[0060] In a first exemplary pathway, a raffinate (from step 455) is provided in a step 505. In a step 510, the raffinate 455 subjected to drying to evaporate water and obtain dried sulfates salts of the metals of interest. In step 515 is subjected to sintering (or baking) at elevated temperatures, such as about 800°C, for a period of time to convert the metals of interest (for example Co. N, and Mn) to their corresponding oxides. During the sintering process, the lithium remain as a soluble sulfate salt. In step 520, the sintered mixture is dispersed in water and subjected to filtration to produce a filtrate of the insoluble metal oxides (recovered in step 525) and a raffinate of soluble lithium sulfate (recovered in step 530). In step 535, the lithium sulfate is reacted with a suitable carbonate salt, such a NaA'CU to form lithium carbonate. The recovered metal oxides and lithiumcarbonate can subsequently be purified and recycled for subsequent use in new batteries or other applications. This exemplary pathway is further illustrated by Example 7 below.

[0061] In a first exemplary pathway, a raffinate (from step 455) is provided in a step 505. In a step 550, urea is added the raffinate 455. The urea reacts with metals of interest (for example Co, N, and Mn), converting them to their corresponding hydroxides. During the sintering process, the lithium remain as a soluble sulfate salt. In step 555, the mixture resulting from step 550 is dispersed subjected to filtration to produce a filtrate of the insoluble metal oxides (recovered in step 560) and a raffinate of soluble lithium sulfate (recovered in step 565). In step 570, the lithium sulfate is reacted with a suitable carbonate salt, such a Na2COs, to form lithium carbonate. The recovered metal hydroxides and lithium carbonate can subsequently be purified and recycled for subsequent use in new batteries or other applications. This exemplary pathway is further illustrated by Example 8 below.

[0062] EXAMPLES

[0063] Materials. Ammonium persulfate (APS, >98 %), NaCl (AR), urea (AR) and H2O2 (30 vol %) were purchased from Sigma- Aldrich and used as received unless otherwise noted. Lithium- ion batteries (containing were obtained from commercially available smartphones.

[0064] Instrumentation. Ball Milling (BM). Ball milling was performed using an SPEX samplePrep 8007 mixer / mill.

[0065] Powder X-Ray Diffraction (PXRD). PXRD spectral analysis was conducted using a PANalytical multipurpose diffractometer with an X'celerator detector (PANalytical X'Pert Pro).

[0066] X-Ray Photoelectron Spectroscopy (XPS). High resolution XPS spectra were collected using a PHI QuanteraXPS scanning microprobe with an Al monochromatic Ka source (15 KV, 20 mA).

[0067] Inductively coupled plasma optical emission spectroscopy (ICP-OES). ICP-OES spectra were obtained using an AGILENT 725 ICP-OES.

[0068] Example 1.

[0069] The anode and cathode of a spent lithium-ion battery w ere immersed into a NaCl solution for discharge after disabling overcharge protection. The battery was disassembled and soaked into deionized water for up to 2 hours. The anode was separated from the cathode. Then, the anode was placed in a w ater bath at temperature of about 100 °C for about 8 hours. The graphite powder and copper foil of the anode w ere then isolated and collected separately.

[0070] The cathode underwent a similar treatment process as the anode. Following a water bath, the separator was peeled off from the cathode (active materials and Al foil). The cathode was reimmersed into a water bath and the active materials (e.g., lithium-, cobalt-, nickel-containingmaterials, etc.) gradually fell off the Al foil with the assistance of mechanical agitation. In this experiment, magnetic stirring was used (other forms of mechanical stirring may be more efficient in scaled-up and / or industrial recycling processes). After evaporating the water out, the active materials from the cathode were obtained. Next, APS and collected active materials were mixed, at a 1 : 1 wt: wt ratio, by ball milling for 2 hours. The milled mixture was then sintered at 500 °C for 30 mins in a box furnace. Then, a leaching process was conducted. For the leaching process, the sintered materials were mixed with water at a sintered materials-to-water weight ratio of 1 / 10. The pH value of the leaching solution was observed to be about 6.5. After 2 hours of leaching, the whole solution was passed through 50 pm filter paper to produce a clear solution (raffinate) containing COSO4 XH2O and Li2SO4 XH2O. When the water was from the solution was evaporated, solid COSO4 XH2O and Li2SO4 XH2O remained and were recovered. The filtered insoluble materials were sintered at 800 °C for 30 mins, to obtain pure CO3O4.

[0071] FIG. 6 is a PXRD pattern of a sample of the milled mixture after sintered at 500 °C for 30 mins. The PXRD pattern indicates that carbon (C), CO3O4 and Li2Co(SC>4)2 are the major compositional constituents of the sintered mixture. Without be bound to any particular theory’, it is believed that the reaction occurring during the ball milling and sintering steps is as shown in Equation 1:

[0072] Notably Li2SO4 was not detected in the X-ray diffraction (XRD) analysis, possibly owing to its minor quantity in the sample. Following the leaching process, the water-soluble and insoluble products were directly separated as described above. The clear solution (raffinate) exhibited a faint pink color and was subjected to heating; the chemical reaction can be described as shown in Equations 2 and 3:(AH4)2SO4II2S04+ 2NII3(2)Li2C o^SOs,')2+ 2Co3O4+ 6H2S04Li2SO4+ 7CoS04+ O2+ 6H2O (3)

[0073] In Equation 3, the CoSO4 and Li2SC>4 were obtained as CoSO4 XH2O and Li2SC>4 XH2O. The final product exhibited a light pink color, which is indicative of C0SO4 H2O. FIG. 7 is a PXRD pattern of a sample of the final dried product obtained from the raffinate.

[0074] The insoluble product, a combination of C and CO3O4, were sintered at 800 °C for 30 mins as described above to remove remaining carbon. Carbon tends to combust at a rapid pace at 800 °C, leaving behind pure CO3O4 as confirmed by the PRXD pattern (FIG. 8) sintered insoluble product. XPS separately confirmed the elemental composition of the extractive materials (FIG. 9).

[0075] The efficiency of Li extraction was calculated by x = (mi + ms) / M, where mi, ms. and Mare the moles of recovered Li, the moles unrecovered Li, and total moles of Li in the cathode active materials, respectively. ICP-OES measurement proved the extraction efficiency of Li in this example reaching about 97.5% with Li2SO4 XH2O as the resulting product. The extraction efficiency resulting from this example outperforms most pyrometallurgy and hydrometallurgy methods in the art. In addition to increased extraction efficiency, the method exemplified by this example is an improvement over pyrometallurgy and hydrometallurgy methods in the art because 1) it is strong acid-and strong base-free, 2) the entire method is marked by low potential hazard and minimal waste generation due to the use of water and extractive reagents that are free of heavy and toxic metals, and 3)the method requires low energy’ consumption, particularly with respect to the temperature (thermal input) requirements of numerous steps of the method, compared to similar pyrometallurgical and / or hydrometallurgical methods.

[0076] Example 2

[0077] An anode and cathode were immersed into NaCl solution for discharge after disabling overcharge protection. Then the battery was taken apart and soaked into water for up to 2 hours. The cathode and anode were easily separated from the organic separator. After that, they were placed in a box furnace and heated to 180 °C for 30 min to remove the binder. The resulting product was then put into water and ultrasonicated for 10 min. The graphite of anode and active materials of cathode (specifically LiCoCh, Li(Ni8CoiMm)O2, Li(NigCoiAli)O2, LiNiCh, LiMnCh and LiFePCh) were easily dispersed into the water. Copper and aluminum foils that serve as current collectors were collected and recycled. After evaporating the water out, the mixture of anode and cathode materials, having the appearance of a black mass, was obtained. Depending on the composition of spent LIBs, the black mass may contain one or more cathode materials. For example, the black mass component obtained by disassembling an iPhone battery is a mixture of LiCoCh and graphite. If you disassemble batteries from both iPhone and Hewlett Packard (HP) laptops, the black mass will contain LiCoCh, LiNiCh, Li(NisCoiMm)O2, and graphite.

[0078] Example 3.

[0079] In this example, the black mass of Example 2 was subjected to an extraction process using APS as the extraction reagent. APS power and black mass (1 : 1 weight ratio) were mixed by ball milling for 2 hours, then sintered at 500 °C for 30 mins in the box furnace. For the leaching process, the sintered materials were mixed with water at a material-to-water weight ratio of 1 / 10. After 2 hours stirring and leaching, the solution was filtered using 50 pm filter paper. The filtered solution (raffinate) was a metal sulfate solution, and the remaining solid (filtrate) was graphite which can be directly recovered. The leaching efficiency of the main recovered elements are listed in Table 1. The efficiency of extraction was calculated by x = (mi + ms) / M. where mi, ms, and Mare the moles of recovered, unrecovered, and total moles of an element.

[0080] In instances where the black mass is derived from or contains LiFePOr. the sintering temperature of this example is raised to 600 °C and the sintering time is increased to 120 min. Under these conditions, graphite can be completely removed and filtered to obtain a metal sulfate solution and an iron phosphate solid.

[0081] Example 4.

[0082] In this example, the black mass of Example 2 was subjected to an extraction process using APS as the extraction reagent in conjunction with H2O2. APS power and black mass (1:1 weight ratio) were mixed by mechanical vibration for 10 min, then sintered at 500 °C for 30 mins in a box furnace. For the leaching process, the sintered materials were directly added to a vigorously stirring blender while the black mass was still hot (around 220 to 300 °C). In the blender was a solution of APS and H2O2 a having an APSiFLCh weight ratio of 1 / 10. After 30 minutes of stirring and leaching, the solution was filtered using 50 pm filter paper. The filtered solution (raffinate) is a metal sulfate solution, and the remaining solid (filtrate) is graphite which can be directly recovered. The leaching efficiency of the main recovered elements are listed in Table 2. The efficiency of extraction was calculated as described in Example 3.Table 2.

[0083] As discussed in Example 3, in instances where the black mass only contains LiFePCL and graphite, the sintering temperature in this example is raised to 600 °C and the sintering time is increased to 120 min. Under these conditions, graphite can be completely removed and filtered to obtain a metal sulfate solution and an iron phosphate solid. If the black mass contains LiFePO4 and any one or more other cathode materials (LiCoCh, Li(Ni8CoiMm)O2, Li(NisCoiAli)O2, LiNiCh, LiMnCh), it should be sintered under 600 °C for 120 min to completely remove graphite and then ball milled for 60 min. For leaching process, the sintered black mass can then be added to an APS solution at a black mass / solution weight ratio of 1 / 20, and then H2O2 is slowly added. After 60 min stirring, the solution will be filtered using 50 pm filter paper. The filtered solution(raffinate) is a metal sulfate solution, and the remaining solid (filtrate) is LiFePO4. The LiFePOi can then be added to a new APS solution at 60 °C for 60 min and filtered by 50 gm filter paper. The resulting filtered solution (raffinate) is lithium sulfate solution and remaining solid (filtrate) is iron phosphate.

[0084] Example 5.

[0085] In this example, the black mass of Example 2 was subjected to an extraction process using APS as the extraction reagent in conjunction with H2O2. First, the black mass was sintered at 220 °C for 30 mins in a box furnace and the ball milled for 60 minutes. For the leaching process, the sintered black mass was then added to an APS solution at 60°C with a black mass / solution weight ratio of 1 / 20, and is then H2O2 (25 % solution) is slowly added until a mass (g) to volume (ml) ratio of APS to H2O2 of 1:2 is reached. After 60 minutes of stirring and leaching, the solution was filtered using 50 pm filter paper. The filtered solution (raffinate) is a metal sulfate solution, and the remaining solid (filtrate) is graphite which can be directly recovered. To ensure optimized extraction efficiency and cost considerations, the optimal mass ratio of APS to black mass is 2.4: 1. The leaching efficiency of the main recovered elements are listed in Table 3. The efficiency of extraction was calculated as described in Example 3.Table 3.

[0086] In instances where the black mass only contains LiFePOi and graphite, the sintering temperature in this example is raised to 600 °C and the sintering time is increased to 120 min, and the resulting sintered product is ball milled for 60 minutes. Under these conditions, graphite can be completely removed after sintering. After that, the remaining material is added to an APS solution at 60 °C for 60 min without H2O2 and then filtered by 50 pm filter paper. The resulting solution is a lithium sulfate solution and the remaining solid is iron phosphate.

[0087] If the black mass contains LiFePOi and any one or more other cathode materials (LiCoCh, Li(Ni8CoiMm)O2, LitNisCoiAlijCh, LiNiCh, LiMnCh), it should be sintered under 600 °C for 120 min to completely remove graphite and then ball milled for 60 min. For leaching process, the sintered black mass can then be added to an APS solution with a solid-liquid ratio of 1 / 20, and then added H2O2 slowly. After 60 minutes of stirring, the solution is filtered using 50 pm filter paper. The filtered solution (raffinate) is a metal sulfate solution, and the remaining solid (filtrate) is LiFePOi. The LiFePOi is then added to a new APS solution at 60 °C for 60 min and filtered by 50 pm filter paper. The resulting filtered solution (raffinate) is lithium sulfate solutionand remaining solid (filtrate) is iron phosphate.

[0088] Example 6.

[0089] In this example, the black mass of Example 2 was subjected to an extraction process using APS as the extraction reagent in conjunction with H2O2. The black mass was sintered under 220 °C for 30 min and then directly added to a vigorously stirring blender while the black mass was still hot (220 °C). In the blender was the solution of APS and H2O2 (mass (g) to volume (ml) ratio of APS to H2O2 of 1:2). The solid-liquid ratio of black mass to APS-H2O2 solution was 1 / 20. The strong shear of the stirring paddles and the high temperature of the powder were utilized to significantly increase the reaction rate. After stirring for 60 min, the whole solution went through 50 pm filter paper. The filtered solution was a metal sulfate solution, and the remaining solid was graphite which can be directly recovered.

[0090] If the black mass only contains LiFePCh and graphite, it should be sintered under 600 °C for 120 min and then ball milled for 60 min and then directly added to a vigorously stirring blender while the black mass was still hot (around 220 to 300 °C). In the blender was the solution of APS and H2O2. The solid-liquid ratio of black mass to APS-H2O2 solution was 1 / 20. After stirring for 60 min, the solution is then filtered through 50 pm filter paper. The filtered solution (raffinate) is a lithium sulfate solution, and the remaining solid (filtrate) is FePOi

[0091] If the black mass contains LiFcPOi and any one or more other cathode materials (LiCoCh. LifNisCoiMnijOz, LifNisCoiAlijCh, LiNiCh, LiMnCh), it should be sintered under 600 °C for 120 min to completely remove graphite and then directly added to a vigorously stirring blender while the black mass is still hot (for example, around 220 °C). In the blender is a solution of APS and H2O2 as described above in this example. After stirring for 60 min, the solution is filtered through 50 pm filter paper. The filtered solution (raffinate) is a metal sulfate solution, and the remaining solid (filtrate) is LiFePCL which can be directly recovered. After that, the LiFePCL is added to APS solution at 60 °C for 60 min without H2O2 and then filtered by 50 pm filter paper. The resulting solution (raffinate) is a lithium sulfate solution and remaining solid (filtrate) is iron phosphate.

[0092] Example 7.

[0093] In Examples 3-6, raffinates containing sulfate salts of metals on interest (Li, Co. Ni and Mn) were obtained. In this example, a method is provided to separate the individual metal elements.

[0094] First, a raffinate solution containing sulfate salts of metals on interest (Li, Co, Ni and Mn) was evaporated to produce a powder. The powder was sintered in a box furnace at 800 °C for up to 30 mins and then dispersed into DI water. The dispersion was then filtered, to produce an insoluble filtrate of metal oxides (e.g., CO3O4, NiO, and MnCh) and a raffinate solution of lithiumsulfate. Excess sodium carbonate was then added to the lithium sulfate solution and heated to 90 °C to produce solid lithium carbonate, which was recovered by hot filtration.

[0095] In this example, sintering temperature should be above 600 °C and below 860 °C in view of the decomposition temperature of certain transition metal sulfates formed during the process (around 600 °C) and the decomposition temperature of lithium sulfate (around 860 °C). Lower sintering temperatures require longer sintering times. The sintering time at 600 °C should be around 120 min.

[0096] Also in this example, the type of metal oxide(s) obtained will depend on the composition of the black mass. If the black mass contains only a single ty pe of anode material, then the resulting metal oxide is a single component material. If the black contains more than one anode material, then a mixture of metal oxides will be present.

[0097] Example 8.

[0098] In Examples 3-6, raffinates containing sulfate salts of metals on interest (Li, Co, Ni and Mn) were obtained. In this example, another method is provided to separate the individual metal elements.

[0099] While stirring, urea was added to the resulting metal sulfate solution (mass ratio of urea to black mass = 2: 1), and the pH was adjusted to about 7 with ammonia. After 30 minutes of stirring, metal hydroxides (e.g., Co(OH)2, Ni(0H)2 and Mn(0H)4) were formed, and metal hydroxides other than lithium hydroxide are precipitated and recovered after filtration. Lithium carbonate precipitate is obtained by adding excess sodium carbonate to the filtered solution containing lithium hydroxide, which could be recovered by filtration.

[0100] While the detailed description, figures and examples of the disclosure are targeted toward the recovery' of lithium and other metals and materials of interest from lithium-ion batteries, the disclosure should not be viewed as limited to the recovery of lithium, nor should the disclosure be viewed as limited to the recovery other metals and materials of interest from lithium-ion batteries. Instead, the novel and unique methods and compositions described in detailed description, figures and examples can be applied to any rechargeable battery' (such as, for example, sodium ion batteries, magnesium ion batteries, silver-zinc batteries, and so on) that has any type of metals or other materials, the recovery and recycling of which would greatly improve the environment increase the sustainability of battery technology.

[0101] FIG. 10 provides a graphical overview of the advantages and shortcomings of prior art methods for the recovery' of lithium and other metals of interest from spent lithium-ion batteries. Compared with these methods, some notable advantages of the novel and inventive compositions and methods described herein are as follows:

[0102] Low temperature treatment, low energy consumption and low cost

[0103] Compared to pyrometallurgical methods, our method has a low heating temperature and short heating time, resulting in a significant reduction in overall energy consumption.

[0104] No strong acids or strong alkalis; environmentally friendly.

[0105] Low-cost, environmentally friendly chemicals and significantly reduces wastewater compared to hydrometallurgical methods.

[0106] Simplicity and time efficiency. The methods described herein involve simple sintering, ball milling, and filtration steps, and require only simple equipment, allowing for large- scale production. The overall process is within 3-5 hours, which is simpler and more effective than other prior art methods that can take dozens of hours to process.

[0107] Wide range of applications and high recycling efficiency.

[0108] Our methods can be used for the recovery of economic products in single-component, multi-component mixed systems. The recycling efficiency is high, and the recycled products can be directly used in industrial production and battery production.

[0109] In conclusion, whether from the perspective of economic value, recycling technology or large-scale production, our recycling methods have outstanding advantages and have great potential in the field of battery recycling.

[0110] Although the present invention and its objects, features and advantages have been described in detail, other embodiments are encompassed by the invention. All references cited herein are incorporated by reference in their entireties. Finally, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for cartying out the same purposes of the present invention without departing from the scope of the invention as defined by the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A method for recovering lithium from a lithium-ion batten , the method comprising: isolating a bulk material from a cathode or the cathode and an anode of a lithium-ion battery, the bulk material comprising lithium; reacting the bulk material with a persulfate compound to form lithium sulfate or a hydrate thereof; and recovering the lithium sulfate or the hydrate thereof.

2. The method of claim 1, further comprising: reacting lithium sulfate or the hydrate thereof with a carbonate salt to form lithium carbonate; and recovering the lithium carbonate.

3. The method of claim 1, wherein the bulk material further comprises one or more additional metals of interest.

4. The method of claim 3, wherein the one or more additional metals of interest include cobalt, nickel or manganese.

5. The method of claim 3 or 4, further comprising: forming one or more metal oxides from the one or more metals of interest; and recovering the one or more metal oxides.

6. The method of claim 3 or 4, further comprising: forming one or more metal hydroxides from the one or more metals of interest; and recovering the one or more metal hydroxides.

7. The method of claim 3 or 4, further comprising: forming one or more metal sulfates or hydrates thereof from the one or more metals of interest; and recovering the one or more metal sulfates or hydrates thereof.

8. The method of claim 1, wherein the persulfate compound is provided in the form of an aqueous solution.

9. The method of claim 8, wherein the aqueous solution further comprises hydrogen peroxide.

10. The method of claim I . wherein the method is performed without the use of strong acids or strong bases.

11. The method of claim 1 , wherein the lithium-ion battery is selected from the group consisting of lithium-ion cobalt oxide batteries, lithium-silicon batteries, lithium-ion manganese iron phosphate batteries, lithium-ion manganese-oxide batteries, lithium-ion polymer batteries, lithium-iron-phosphate batteries, lithium-nickel-manganese-cobalt oxides batteries, lithium- nickel-cobalt-aluminum oxides batteries, lithium-sulfur batteries, lithium-selenium batteries, lithium-sulfur / selenium batteries, lithium-nickel oxide batteries, lithium-manganese oxide batteries, lithium iron phosphate batteries, and lithium-titanate batteries.

12. The method of claim 1, wherein the persulfate compound is selected from the group consisting of peroxydisulfuric acid, sodium persulfate, potassium persulfate, calcium persulfate, bis(tetrabutylammonium) peroxydisulfate, benzyltriphenylphosphonium peroxy disulfate, choline peroxy disulfate, ammonium persulfate and combinations thereof.

13. The method of claim 1, wherein the persulfate compound comprises an organic cation.

14. The method of claim 1, wherein the persulfate compound is ammonium persulfate.

15. Use of an aqueous solution comprising a persulfate compound in a method for recovering lithium from a lithium-ion battery.

16. The use of claim 15, wherein the aqueous solution further comprises hydrogen peroxide.

17. The use of claim 15, wherein the aqueous solution comprising the persulfate compound is also used in the method for recovering one or more additional metals of interest.

18. The use of claim 17, wherein the one or more additional metals of interest include cobalt,nickel or manganese.

19. The use of claim 15, wherein the persulfate compound is selected from the group consisting of peroxydisulfuric acid, sodium persulfate, potassium persulfate, calcium persulfate, bis(tetrabutylammonium) peroxydisulfate, benzyltriphenylphosphonium peroxydisulfate, choline peroxy disulfate, ammonium persulfate and combinations thereof.

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