Electrochemical reactor for efficient production of a recovered material from a used battery

Abstract

System and methods for recovering a used battery material from a used battery material using an electrochemical reactor in which the solid-state anode reactant is derived from one or more components of the used battery, are disclosed. The method includes providing a solid-state anode reactant including the used battery material; placing the solid-state anode reactant between an anode current collector and a cation exchange membrane in an electrochemical reactor, applying a voltage to the electrochemical reactor; and collecting a recovered material from a product stream. The electrochemical reactor includes: a cathode compartment with a cathode current collector and a cathode catalyst; an anode compartment with the anode current collector and the solid-state anode reactant; the cation exchange membrane, where the cation exchange membrane is disposed between the cathode compartment and the anode compartment; a feed stream fluidly connected to the cathode compartment; and a product stream fluidly connected to the cathode compartment.

Description

ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCTELECTROCHEMICAL REACTOR FOR EFFICIENT PRODUCTION OF A RECOVERED MATERIAL FROM A USED BATTERYBACKGROUND

[0001] The demand for lithium and lithium-ion batteries (LIBs) has significantly increased over the past decade due to the widespread adoption of consumable electronics and electric vehicles (EVs). The proportion of EVs among all light-duty vehicles has risen from 0.12% in 2015 to 2.1% in 2022 and is projected to achieve at least 10% or even fully dominate the market by the year 2050. However, this rapid expansion in the manufacturing of lithium-ion batteries has led to concerns about depleted lithium reserves, with estimates suggesting that one-third of the Earth's lithium resources could be exhausted by 2050. Additionally, given that the lifespan of advanced batteries typically ranges from 5 to 10 years, the disposal of spent batteries will result in millions of tons of toxic waste. In the United States alone, it is projected that retired EV s will produce 1.2 million metric tons of lithium battery waste annually. Therefore, there is an urgent need to establish new LIB recycling processes to transform hazardous battery waste into valuable battery manufacturing feedstocks, thus fostering a circular economy for lithium and other valuable metals inside the battery.

[0002] The recycling of LIBs can be approached in two fundamental ways: separating lithium from other elements (such as valuable transition metals) in spent battery electrodes or direct recycling of the LIB cathode materials. Direct recycling offers advantages in terms of lower energy and chemical consumption. However, this approach is often limited by quality control of the recovered cathode materials. In contrast, separation methods break down spent batteries into fabrication feedstocks, which fit well with existing battery manufacturing supply chains, resulting in improved quality control of the final battery products. Lithium separation can be effectively achieved through energy- or chemically-intensive processes, as demonstrated by conventional methods: pyrometallurgy and hydrometallurgy. Both pyrometallurgical and hydrometallurgical strategies offer scalability and sufficient lithium recovery rates (above 90%). However, pyrometallurgy is constrained by high energy consumptions (requiring calcination at approximately 700 °C to yield Li2CO3), while hydrometallurgy demands significant chemical input (using strong acids suchATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT as H2SO4 at concentration > 2 M and oxidants like H2O2 at concentration > 2 M), both of which pose negative environmental impacts. Building on hydrometallurgical methods, emerging technologies such as the contact-electro-catalysis method and the flash joule heating method have been reported in recent years. Despite their advantages, such as reduced acid and oxidant consumption, these approaches face challenges including complex processes, higher energy demands, and scalability limitations.

[0003] Notably, the charging reaction in LIBs is an effective lithium separation process, where Li+is extracted from the cathode material. Compared to the conventional approaches, these delithiation reactions in LIBs offer a milder reaction condition for lithium separation without involving external chemical consumption. Traditionally, these reactions have been mainly realized in LIB battery structures where organic electrolytes and a battery anode were used, and the extracted Li ions were intercalated into graphite. Leveraging this delithiation process for Li separation, some battery recycling systems use organic electrolytes, solid electrolytes, or lithium superionic conductors such as LiyLaaZ^OnCLLZTO). However, safety concerns related to flammable electrolytes, the high costs of the complex electrolyte materials, and scalability challenges have limited the practical application of the delithiation method in LIB recycling. Therefore, there is a pressing need to develop a safe, affordable, scalable, and energy-efficient lithium separation approach for LIB recycling.SUMMARY

[0004] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0005] In one aspect, embodiments disclosed herein relate to a method for recovering used battery material from a used battery. The method includes providing a solid- state anode reactant including the used battery material; placing the solid-state anode reactant between an anode current collector and a cation exchange membrane in an electrochemical reactor, applying a voltage to the electrochemical reactor; and collecting a recovered material from a product stream. The electrochemical reactorATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT includes: a cathode compartment with a cathode current collector and a cathode catalyst; an anode compartment with the anode current collector and the solid-state anode reactant; the cation exchange membrane, where the cation exchange membrane is disposed between the cathode compartment and the anode compartment; a feed stream fluidly connected to the cathode compartment; and a product stream fluidly connected to the cathode compartment.

[0006] In another aspect, embodiments disclosed herein relate to an electrochemical reactor for recovering used battery material from a used battery. The electrochemical reactor includes: a cathode compartment including a cathode current collector and a cathode catalyst; an anode compartment including an anode current collector and a solid-state anode reactant; a cation exchange membrane disposed between the cathode compartment and the anode compartment; a feed stream fluidly connected to the cathode compartment; and a product stream fluidly connected to the cathode compartment; where the solid-state anode reactant comprises the used battery material and the product stream comprises a recovered material.

[0007] Other aspects and advantages of the claimed subject matter will be apparent from the following description and appended claims.BRIEF DESCRIPTION OF DRAWINGS

[0008] FIG. 1 shows an exploded view of an electrochemical reactor in accordance with one or more embodiments.

[0009] FIG. 2 illustrates a roll-to-roll reactor system in accordance with one or more embodiments.

[0010] FIG. 3 is a schematic diagram of the method in accordance with one or more embodiments.

[0011] FIG. 4 schematically illustrates an electrochemical reactor in accordance with one or more embodiments.

[0012] FIG. 5 is a diagram showing the cell voltages under current densities of 0.05 mA / cm2, 0.10 mA / cm2, 0.25 mA / cm2, 0.50 mA / cm2, and 1.00 mA / cm2, of an electrochemical reactor in accordance with at least Example 1.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT

[0013] FIG. 6 is a diagram showing the concentrations of lithium, iron, phosphorus, and aluminum in the catholyte at 0.5 mA / cm2, using an electrode prepared by coating LFP BM on a 2.5 x 2.5 cm2carbon paper, in accordance with at least Example 1.

[0014] FIG. 7 is a diagram showing the recovery rates of lithium for different current densities (0.05 mA / cm2, 0.10 mA / cm2, 0.25 mA / cm2, 0.50 mA / cm2, and 1.00 mA / cm2), calculated based on the average initial total lithium amount, and the error bars indicating standard deviation, in accordance with at least Example 1.

[0015] FIG. 8 is a diagram showing the mass balance of lithium where the amount of lithium left in the post-reaction electrode and the amount of lithium in the catholyte add up to the average initial lithium amount, in accordance with at least Example 1.

[0016] FIG. 9 is a diagram showing the FE of OER and the delithiation reaction with error bars indicating standard deviation, in accordance with at least Example 1.

[0017] FIG. 10 is a diagram showing cell voltages for different loadings of the cylindrical sample from 2.0 mg / cm2to 18.0 mg / cm2, in accordance with at least Example 2.

[0018] FIG. 11 is a diagram showing recovery rates for different loadings of the cylindrical sample and different delithiation speeds (0.1 C, 0.2 C, and 0.4 C), in accordance with at least Example 2.

[0019] FIG. 12 is a diagram showing the resistivity of the prismatic samples adding different amounts of conductive carbon, in accordance with at least Example 2.

[0020] FIG. 13 is a diagram showing the cell voltages of the prismatic sample adding different amounts of conductive carbon with a protection cell voltage of 5.0 V, in accordance with at least Example 2.

[0021] FIG. 14 is a diagram showing recovery rates and FE based on Li+concentration in the catholyte of the prismatic sample, adding different amounts of conductive carbon, at a protection cell voltage of 5.0 V, in accordance with at least Example 2.

[0022] FIG. 15 is a schematic diagram of a scaled-up BM recycling process that includes three steps, in accordance with one or more embodiments.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT

[0023] FIG. 16 is a photo of the pre-reaction Ti current collector, top left, the preextraction BM coated on the current collector, top right, the post-reaction BM coated on the current collector, bottom left, and the post-reaction BM removed from the current collector, bottom right, in accordance with at least Example 3.

[0024] FIG. 17 is a photo of the post-reaction BM of 10 cycles, left, and of the catholyte LiOH-FhO product (2 cycles) after freeze-drying, right, in accordance with at least Example 3.

[0025] FIG. 18 is a diagram showing the XRD pattern of the LiOHTEO product and the post-reaction BM, in accordance with at least Example 3.

[0026] FIG. 19 is a diagram showing the cell voltages and recovery rate during the 500- h stability test, in accordance with at least Example 3.

[0027] FIG. 20 is a diagram showing the Li+concentration in the catholyte and the yield of post-reaction BM during the 500-h stability test, in accordance with at least Example 3.

[0028] FIG. 21 shows a top view of an exemplary roll-to-roll reactor system in accordance with at least Example 4.

[0029] FIG. 22 shows a side view of the exemplary roll-to-roll reactor system in accordance with at least Example 4.

[0030] FIG. 23 is a diagram showing the cell voltages and FE of a roll-to-roll device using a non-coated CEM, in accordance with at least Example 4.

[0031] FIG. 24 is a diagram showing the Li+concentration and recovery rate of a roll- to-roll device using a non-coated CEM, in accordance with at least Example 4.

[0032] FIG. 25 is a diagram showing the cell voltages and FE of a roll-to-roll device using a PTFE-reinforced CEM, in accordance with at least Example 4.

[0033] FIG. 26 is a diagram showing the Li+concentration and recovery rate of a roll- to-roll device using a PTFE-reinforced CEM, in accordance with at least Example 4.

[0034] FIG. 27 is a diagram showing the cell voltages and FE of a roll-to-roll device using a PTFE-reinforced CEM for 26 cycles to reach a high LiOH concentration by recycling the 30 mL catholyte, in accordance with at least Example 4.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT

[0035] FIG. 28 is a diagram showing the Li+concentration and recovery rate of a roll- to-roll device using a PTFE-reinforced CEM for 26 cycles to reach a high LiOH concentration, in accordance with at least Example 4.DETAILED DESCRIPTION

[0036] In the following detailed description of embodiments of the disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the disclosure. However, it will be apparent to one of ordinary skill in the art that the disclosure may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0037] Throughout the application, ordinal numbers (e.g., first, second, third, etc.) may be used as an adjective for an element (i.e., any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.

[0038] In the following description of the figures listed above in the “Brief Description of Drawings”, any component described with regard to a figure, in various embodiments disclosed herein, may be equivalent to one or more like-named components described with regard to any other figure. For brevity, descriptions of these components will not be repeated with regard to each figure. Thus, each and every embodiment of the components of each figure is incorporated by reference and assumed to be optionally present within every other figure having one or more like-named components. Additionally, in accordance with various embodiments disclosed herein, any description of the components of a figure is to be interpreted as an optional embodiment which may be implemented in addition to, in conjunction with, or in place of the embodiments described with regard to a corresponding like-named component in any other figure.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT

[0039] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a horizontal beam” includes reference to one or more of such beams.

[0040] Terms such as “about,” “approximately,” “substantially,” etc., mean that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[0041] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the present specification and associated claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by one or more embodiments described herein. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claim, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0042] It is to be understood that the compositions described herein may be free of any component, or composition not expressly recited or disclosed herein. Any method may lack any step not recited or disclosed herein. Likewise, the term “comprising” is considered synonymous with the term “including.” Whenever a method, composition, element or group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0043] It is to be understood that one or more of the steps shown in the flowcharts may be omitted, repeated, and / or performed in a different order than the order shown. Accordingly, the scope disclosed herein should not be considered limited to the specificATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT arrangement of steps shown in the flowcharts. Although multiple dependent claims are not introduced, it would be apparent to one of ordinary skill that the subject matter of the dependent claims of one or more embodiments may be combined with other dependent claims.

[0044] Conventional Li-ion battery (LIB) recycling technologies, such as pyrometallurgy and hydrometallurgy, are constrained by high energy- or chemicaldemands, requiring elevated temperatures and substantial chemical input to smelt or leach solid battery materials for lithium separation. By leveraging the delithiation chemistry of battery cathode materials as a separation mechanism, a recycling method and a zero-gap membrane electrode assembly (MEA) reactor is disclosed herein, for sustainable, scalable, and cost-effective lithium recovery from wastes such as LiFePO4 (LFP) battery black mass (BM). In a zero-gap MEA reactor, the solid-state anode reactant, the cation exchange membrane, and cathode catalyst are in contact with each other. This approach eliminates the need for traditional hydrometallurgy processes involving acid and H2O2 leaching. Conventional methods exhibit scalability advantages yet are plagued by either high energy consumption or substantial chemical inputs, resulting in elevated CO2 emissions and significant chemical waste generation. Conversely, other emerging technologies display reduced energy consumption and chemical input. However, they are constrained by factors such as elevated costs, restricted quality of the recovered material, and inadequate scalability. Compared to conventional methods, the system and method disclosed herein significantly reduce external chemical inputs such as H2SO4 and H2O2 required to leach BM and carbonates (Na2COa) to produce product (Ei2CO3) as in the hydrometallurgy method. In addition, the energy input was reduced by avoiding high- temperature treatments in the pyrometallurgy method and utilizing sustainable electricity. Finally, EiOH was directly produced as the final product without further precipitation or post-treatment, where external alkaline solutions (Ca(OH)2 or NH3 H2O) are used to convert Ei2CO3 to EiOH.

[0045] According to one or more embodiments, a system or method for recovering a used battery material from a used battery involves an electrochemical reactor in which the solid-state anode reactant is derived from one or more components of the used battery. The used battery material includes one or more substances contained in theATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT one or more components. The system and method can produce a recovered material from used battery material through one or more chemical reactions, when a current is applied to the electrochemical reactor. The recovered material may be treated to recycle it and produce battery reagents needed to regenerate a fresh battery. The one or more components may include a used battery cathode. The system and method may recover from the cathode material of a waste battery at least a portion of valuable materials in the used battery material. For example, the system and method may recover from the cathode material of a waste battery at least 10 %, for example at least 20%, for example at least 30%, for example at least 40 %, for example more than 50%, for example at least 60%, for example at least 70%, for example at least 80%, for example at least 90% of valuable materials in the used battery material, for example, lithium.

[0046] The used battery may be a spent lithium battery including a spent lithium battery electrode. A lithium battery typically includes one or more lithium compounds in the cathode of the battery and one or more carbon compounds in the anode of the battery. When the used battery is a used lithium battery, the used battery material may include lithium iron phosphate (LiFePCL, also termed LFP), lithium manganese oxide (LiMn2O4), lithium nickel manganese cobalt oxide (LiNixMnyCozO2, also termed NMC), or for example 50 % nickel, 30% manganese, 20% cobalt (NMC532). The mixture of one or more of these materials and the conductive carbon obtained together from the spent battery’s cathode is referred to herein as black mass (BM). The black mass may include a mixture of valuable metals obtained from shredded and processed end-of-life lithium-ion batteries. This mixture may contain metals such as lithium, cobalt, nickel, manganese, and copper. The black mass may be from multiple sources, for example multiple spent batteries. The black mass may be a blend from spent batteries of different types, such as NMC (lithium nickel manganese cobalt), NCA (lithium nickel cobalt aluminum), LFP (lithium iron phosphate), LMFP (lithium manganese iron phosphate), and the like. The recovered material may include ionic lithium (Li+), for example as lithium hydroxide (LiOH).

[0047] According to one or more embodiments of the present invention, the used lithium battery material is a used lithium battery cathode material. After discharging, dismantling, and pretreatment a used lithium battery cathode electrode can be placed in the anode side of the reactor as the solid-state anode reactant, for recycling.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCTPretreatment may include treatments such as scrapping, washing, milling, and coating. The used lithium battery cathode electrode is formed of one or more substances that include the used lithium battery cathode material. A suitable used battery cathode material is LiFcPCL (LFP). Other suitable used battery cathode materials include lithium manganese iron phosphate, lithium manganese oxide, and NMC’s of the general formula LiNixMnyCozO2 such as LiNio.5Mno.3Coo.2O2 (NMC532). De-lithiation of the used lithium battery cathode material releases Li+.

[0048] According to one or more embodiments of the present invention, the used lithium battery material is black mass. The electrochemical reactor is applied for the recovery of lithium from the black mass. The black mass obtained from used lithium batteries may be milled to powder. The black mass may be milled in a ball milling machine for a time, for example for a time ranging from 2 to 15 minutes. The black mass may be milled according to any suitable milling method, as long as the black mass is in a powder form that enables further coating. An amount of the milled black mass may then be mixed with an amount of conductive carbon if needed to lower the resistance, for example an amount of black mass ranging from 2 to 18 mg / cm2, depending on the active area, may be mixed with an amount of conductive carbon ranging from 0 to 5%. The milled black mass and optional conductive carbon may then be mixed with an amount of binder to form a black mass composition, for example an amount of binder ranging from 0 to 5%. The black mass composition may then be dispersed in IPA such that the black mass may be evenly coated, for example when coating by doctor-blade, 320 mg black mass may be dispersed in 0.8 mL, and applied to a current collector (such as Al foil or a Ti plate) before the recycling process, to produce a solid-state anode reactant. After recycling, LiOH is collected in the catholyte, and post reaction ferric phosphate FePCU obtained can be washed or sonicated down from the anodic current collector, and the current collector can be reused. The remaining black mass may be black mass of used LFP batteries. It will be understood that as used herein a LFP battery is a lithium battery with a LFP electrode, that is lithium battery in which a cathode electrode is formed of battery material that includes LFP.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT

[0049] The system or method for recovering a used battery material from a used battery may be applied directly to spent cathodes without the need to separate black mass from the current collector.

[0050] One or more embodiments disclosed herein relate to reactor designs for the continuous and direct production of recovered material, such as lithium hydroxide (LiOH), from used lithium battery cathode material. The used battery cathode material, such as in the form of a battery cathode electrode, is placed on the anode side. Placement on the anode side facilitates a de-lithiation reaction in an aqueous solution. The aqueous de-lithiation reaction allows efficient LiOH production. The present technology is distinct because of the reactor design of placing the battery cathode electrode on the anode side in contact with the cation exchange membrane (CEM), where the membrane is in contact with the cathode catalyst.

[0051] FIG. 1 shows an exploded view of an electrochemical reactor 100 according to one or more embodiments of the present invention. The electrochemical reactor 100 includes an anode current collector 102, a solid-state anode reactant 104, an anode gasket 106, a cation exchange membrane 108, a cathode gasket 110, a cathode catalyst 112, and a cathode current collector 114. The electrochemical reactor 100 includes a cathode compartment, an anode compartment, and the cation exchange membrane 108. The cation exchange membrane 108 is disposed between the anode compartment and the cathode compartment. The anode compartment includes the anode current collector 102, the solid-state anode reactant 104, and the anode gasket 106. The cathode compartment includes the cathode current collector 114, the cathode catalyst 112, and the cathode gasket 110. It will be understood that electrochemical reactor 100 is not limited to anode current collector 102, a solid-state anode reactant 104, an anode gasket 106, a cation exchange membrane 108, a cathode gasket 110, a cathode catalyst 112, and a cathode current collector 114 and may contain additional suitable components.

[0052] As seen in FIG. 1, the anode current collector 102, anode gasket 106, cation exchange membrane 108, cathode gasket 110, and cathode current collector 114 stack at their respective perimeters to form electrochemical reactor 100 with the anode compartment and the cathode compartment. The anode compartment includes a space defined by the anode current collector 102, the anode gasket 106, and the cationATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT exchange membrane 108, where the space is configured to contain the solid-state anode reactant 104. Further, the space of the anode compartment is configured to contain an anode fluid. Anode gasket 106 provides a seal between anode current collector 102 and cation exchange membrane 108. The cathode compartment includes a space defined by the cathode current collector 114, the cathode gasket 110, and the cation exchange membrane 108, where the space is configured to contain the cathode catalyst 112. Further, the space of the cathode compartment is configured to contain a cathode fluid. Cathode gasket 110 provides a seal between cathode current collector 114 and cation exchange membrane 108. When the anode compartment contains an anode fluid and the cathode compartment contains a cathode fluid, the cation exchange membrane 108 allows selective exchange of species between the anode fluid and the cathode fluid.

[0053] In one or more embodiments, a feed stream is fluidly connected to the cathode compartment, such that the feed stream is introduced to the space defined by the cathode current collector 114, the cathode gasket 110, and the cation exchange membrane 108, becoming the cathode fluid. The feed stream comprises water and may further comprise any suitable solutes such as electrolytes such as LiOH. In one or more embodiments, a product stream is fluidly connected to the cathode compartment, such that the product stream comprises the cathode fluid after electrolysis, and a recovered material.

[0054] The recovered material may include lithium in the form of lithium hydroxide. In one or more embodiments, the system includes CO2 and the recovered material is Li2CO3.

[0055] According to one or more embodiments of the present invention, the cation exchange membrane is any suitable cation exchange membrane such as Nafion™, and Nafion™ with a hydrophobic coating.

[0056] In one or more embodiments, the cathode catalyst is a reductive catalyst resistive to alkaline environments, such as nickel foam or platinum on carbon. In one or more embodiments, the cathodic reaction is the four-electron oxygen reduction reaction. In one or more embodiments, the cathodic reaction is the hydrogen evolution reaction (HER). Suitable cathode current collectors include stainless steel and Ti plate.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCTThe H2 gas produced from HER may be collected as green hydrogen for other energy utilization.

[0057] By leveraging a stable cation exchange membrane, such as a Nafion™ membrane, and a cathode catalyst resistive to alkaline environments, such as a cost- effective nickel foam catalyst, the electrochemical reactor exemplified in FIG. 1 may achieve a Faradaic Efficiency (FE) of from about 50 to 100% and a low average cell voltage of from about 0 to 3 V, under ambient temperature and pressure.

[0058] For example, when using EiFePCU (LFP) as a model cathode catalyst, the spent battery electrode also comprises a cation exchange membrane (CEM) and an aqueous hydrogen evolution reaction (HER) electrode to form a zero-gap MEA electrochemical reactor for effective Li separation. There are several advantages in this cell design: 1) The half-cell potential between LFP delithiation (3.45 V vs. Li / Li+) and HER (0 V vs. SHE or 3.04 V vs. Li+ / Li) is only 0.41 V, indicating a low cell potential, which minimizes energy consumption during Li extraction. 2) Polymer- based, low-cost, and large-scale manufactured CEMs may be used, making the Li recycling process easy to implement and scale up. Additionally, the spent LFP cathode does not have to be scraped off from the Al foil current collector, which can be directly used to assemble an MEA cell for efficient Li separation. 3) LiOH is produced directly, a more valuable feedstock for LIB manufacturing when compared to conventional Li2CO3, without requiring further precipitation or post-treatment steps. This feature represents an improvement over conventional battery recycling processes, which typically require external alkaline solutions (such as Ca(OH)2 or NH3 H2O) to convert Li2CO3 to LiOH. Using LFP blackmass (BM) from industrial waste batteries, a high Li recovery rate of at least 10 % and up to 99% may be achieved, with an average cell voltage of 0.93 V, corresponding to an energy consumption of 536 kJ / kgBM. In one or more embodiments, by replacing the cathodic HER reaction with the oxygen reduction reaction (ORR), the cell voltage is further reduced to as low as 0.18 V, resulting in an energy consumption of 103 kJ / kgBM. This is over an order of magnitude lower than the traditional hydrometallurgical methods, which require approximately 2 X 103kJ / kgBM (excluding the pretreatment steps, such as disassembling, and the post-treatment steps, such as precipitation).ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT

[0059] According to one or more embodiments of the present invention, the used lithium battery material is a used lithium battery cathode that is disposed in a roll-to- roll reactor. Thus, in another aspect, embodiments disclosed herein relate to a roll-to- roll reactor. The used battery cathode electrode may be wound onto an unwinder and rewound onto a rewinder. The recovery process may be carried out continuously along the electrode. Upon completion of recycling the initial section of the electrode, the unwinder and rewinder may be rotated, automatically moving the subsequent section of the electrode to the reaction area. FIG. 2 illustrates a roll-to-roll reactor system according to one or more embodiments of the present invention.

[0060] According to one or more embodiments, an electrochemical reactor for recovering used battery material from a used battery, the electrochemical reactor includes: a cathode compartment comprising a cathode current collector and a cathode catalyst; an anode compartment comprising an anode current collector and a solid- state anode reactant; and a cation exchange membrane disposed between the cathode compartment and the anode compartment. The electrochemical reactor may further include a feed stream fluidly connected to the cathode compartment; and a product stream fluidly connected to the cathode compartment. The solid-state anode reactant may include the used battery material. The product stream may include the recovered material. The used battery material may include a substance selected from the group consisting of LiFePC , LiJ h C , NMC’s such as NMC532, black mass, and combinations thereof. The recovered material may include lithium hydroxide. The cathode catalyst may be a reduction catalyst capable of catalyzing the four-electron oxygen reduction reaction or the hydrogen evolution reaction. The cation exchange membrane may be selected from the group consisting of Nafion™ and Nafion™ with a hydrophobic coating. The feed stream may include water, and may further include any suitable solute, such as LiOH. The reactor may recover at least a portion of, for example at least 10%, for example at least 20%, for example at least 30%, for example at least 40%, for example more than 50%, for example at least 60%, for example at least 70%, for example at least 80%, for example at least 90% at least 90% of a metal in the used battery material from the solid-state anode reactant. The metal may include lithium.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT

[0061] In another aspect, according to one or more embodiments, a roll-to-roll reactor system for recovering used battery material from a used battery includes: the electrochemical reactor, an unwinder; a rewinder; and a used battery cathode electrode rolled on the unwinder and rewinder and passing through the electrochemical reactor, wherein within the electrochemical reactor, the used battery cathode electrode is the solid-state anode reactant. As seen in FIG. 2, the roll-to-roll reactor 200 comprises an unwinder 202 and a rewinder 204, with the used battery cathode electrode 206 rolled on the unwinder 202 and rewinder 204 configured to pass the used battery cathode electrode 206 through the electrochemical reactor 208 comprising an anode compartment 208a and a cathode compartment 208b. The electrochemical reactor 208 includes a feed stream fluidly connected to the cathode compartment 208b; and a product stream fluidly connected to the cathode compartment 208b, configured to pump recycled catholyte 210 through the cathode compartment 208b via a pump 212.

[0062] In yet another aspect, a method for recovering used battery material from a used battery includes providing a solid-state anode reactant comprising the used battery material; placing the solid-state anode reactant between an anode current collector and a cation exchange in an electrochemical reactor comprising a product stream; applying a voltage to the electrochemical reactor; and collecting a recovered material from a product stream. The electrochemical reactor may be an electrochemical reactor according to any of the above-described embodiments. Thus, for example, the electrochemical reactor may include a cathode compartment comprising an cathode current collector and an cathode catalyst; an anode compartment comprising the anode current collector and the solid-state anode reactant; the cation exchange membrane, wherein the cation exchange membrane is disposed between the cathode compartment and the anode compartment; a feed stream fluidly connected to the cathode compartment; and the product stream, where the product stream is fluidly connected to the cathode compartment. The solid-state anode reactant may include the used battery material. The product stream may include the recovered material. The used battery material may include a substance selected from the group consisting of LiFePC , LiMn2O4, NMC’s such as NMC532, and black mass. The recovered material may include lithium hydroxide. The cathode catalyst may be a reduction catalyst capable of catalyzing the four-electron oxygen reduction reaction or theATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT hydrogen evolution reaction. The cation exchange membrane may be selected from the group consisting of Nafion™ and Nafion™ with a hydrophobic coating. The feed stream may include water and may further include any suitable solute, such as LiOH. The method may recover at least a portion of, for example at least 10%, for example at least 20 %, for example at least 30%, for example at least 40%, for example more than 50%, for example at least 60%, for example at least 70%, for example at least 80%, for example at least 90% of a metal in the used battery material from the solid- state anode reactant. The metal may include lithium.

[0063] The electrochemical reactor may be part of a roll-to-roll reactor system for recovering used battery material from a used battery. The roll-to-roll reactor system may include the electrochemical reactor, an unwinder; a rewinder; and a used battery cathode electrode rolled on the unwinder and rewinder and passing through the electrochemical reactor, wherein within the electrochemical reactor, the used battery cathode electrode is the solid-state anode reactant, the method may further include once at least a portion of the a metal used in the used battery material is recovered from a section of the used battery cathode electrode disposed within the electrochemical reactor, rotating the unwinder and rewinder such that another segment of the electrode is disposed with the electrochemical reactor.

[0064] One or more embodiments of the method are exemplified by FIG. 3. In FIG. 3, the method 300 for recovering used battery material from a used battery may be broken into three phases, first a pretreatment phase 302, followed by electrolysis 304 and finally post-treatment 306. The pretreatment phase 302 comprises first optionally pretreating 302 the used battery material, such as discharging, disassembling, and scrapping the used battery material to obtain black mass material 310. The black mass material 310 is then milled 312 to a powder in a ball milling machine, for example for about 2 to 15 minutes, which is then coated 314 onto a substrate such as aluminum foil to form a cathode current collector. The electrolysis phase 304 comprises placing the coated electrode into an electrochemical reactor 316 configured to receive water 324 and to produce hydrogen 318, which may be optionally captured, a product stream and a solid product. The post-treatment phase 306 comprises flowing the product stream to an evaporator 320 to produce a lithium product 322 such as LiOH-FhO, and water 324 which may be recycled back to the electrochemical reactor 316. The solidATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT product may be removed from the cathode current collector via washing 326, drying 328, and brushing 330 the product in the form of FcPCL and carbon 332. The cathode current collector may be re-coated 314 and reused for electrolysis 304. The method may further include any suitable post-treatment steps necessary to reuse the cathode current collector and the production of LiOH.EXAMPLESGeneral Methods

[0065] Black mass (BM) samples from used cylindrical and prismatic batteries were provided by TotalEnergies. Li-Ion Battery Cathode - Aluminum foil single side coated by Li FcPCL (241mm L x 200mm W x 84um Thickness) and LiMmCL (241mm Lx200mm WxO.lmm Thickness), were purchased from MTI corporation. The LiNio.5Mno.3Coo.2O2 single-side coated cathodes were purchased from MSE Supplies. Nafion-117 membrane (used as CEM), and Nafion N2100TX membrane (the PTFE- coated membrane used as selective CEM) were purchased from Fuel Cell Store. Nickel foam (L*W-200X300mm, 0.1mm thickness) was purchased from Amazon. Nafion solution (D520) was purchased from Ion Power. Hydrogen peroxide (H2O2, 30%), sulfuric acid (H2SO4, 98%), and 2-proponal were purchased from Sigma Aldrich. Millipore water (18.2 MQ-cm) was used throughout all experiments.

[0066] Electrochemical measurements were obtained as described here, unless otherwise specified. The cathode side was supplied with DI water for the HER reaction. 30 mL and 40 mL of catholyte was circulated during the reaction, where the flow rate was controlled by a syringe pump at 1.5 mL / min. The flow rate at the outlet was calibrated using a measuring cylinder. All cell resistances were measured by potentio static electrochemical impedance spectroscopy (PEIS), and all the cell voltages are reported without any IR compensation.Example 1 - Small Scale Reactor

[0067] This example demonstrates a small-scale reactor for recovering lithium from spent battery materials, exemplifying a reactor as illustrated in FIG. 1 and further exemplifying a reactor and reactions as illustrated in FIG. 4. FIG. 4 schematically illustrates an electrochemical reactor in which the anode current collector is denotedATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT anode, the solid-state anode reactant includes LiFcPC (LFP), the cation exchange membrane includes Nation™ membrane, the cathode catalyst includes nickel (Ni) foam, and the cathode current collector is denoted cathode. Thus, in FIG. 4, the used battery cathode material is LiFePC . It will be understood that while not shown in FIG. 4, the electrochemical reactor may include a cathode gasket and an anode gasket. As shown in FIG. 4, the anodic reaction is the de-lithiation of LiFePO4: LiFePO4 — > Li++ FePO4 + e", thereby releasing Li+. The released Li+transports through the cation exchange membrane (such as Nafion™) to the catholyte and forms LiOH. As shown in FIG. 4, the cathodic reaction is the hydrogen evolution reaction (HER). As shown in FIG. 4, the reactor includes a feed stream comprising deionized water and a product stream comprising deionized water and LiOH. The LFP electrode is positioned on the anode side as the working electrode, while Ni foam was chosen as the HER catalyst on the counter electrode to guarantee stability in the alkaline environment, sufficient activity under low current density, and affordability. On the anode side (which corresponds to the cathode in LIBs), Li+ions are released during the delithiation of LLP. The Li+ions are transported through the CEM and finally coupled with the OH" generated by HER to form LiOH in the cathode chamber.

[0068] A small-scale reactor (active area 4 cm2) was used to evaluate the performance and optimization for the battery recovery test. Parameters that influence both the energy consumption of the process (cell voltage and Faradaic efficiency (FE)) and the quality of the product (LiOH purity and recovery rate) were assessed. The cathode electrode (commercial LFP coated on Al foil) to be recycled was placed on the anode side, while Ni foam was chosen as the catalyst alkaline hydrogen evolution reaction (HER) for its excellent stability, sufficient activity under low current density, and low cost. Nafion™ was used as a stable and robust cation exchange membrane. The delithiation of cathode material releases Li+, and the Li+is transported through the cation exchange membrane to couple with the OH" generated by HER and form LiOH. In addition, the H2 gas produced from HER may be collected, using a gas separation membrane, as green hydrogen for other energy utilization.

[0069] The cell voltage for lithium recovery, consistent with the charging curve of LFP batteries, remained relatively constant at a plateau of from 0.48 V to 1.22 V (for current densities ranging from 0.05 mA / cm2to 1.00 mA / cm2), as shown in FIG. 5. A sharpATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT voltage increase was observed when the electrode depleted its available lithium ions, indicating the completion of lithium recovery. At this point, the reaction also switched from delithiation to the onset of the oxygen evolution reaction (OER). The low plateau cell voltage, coupled with low resistance, ensured the low energy consumption of the system, as evidenced by electrochemical impedance spectroscopy, not shown. The energy consumption can be further lowered by replacing the cathodic HER reaction with ORR, allowing the plateau cell voltage, not shown, to stay below 0.1V, as evidenced by comparing the cell voltage using DI water (bubbled with Argon for 30 minutes before the reaction) and DI water with O2 (5 seem, via Y connector) under 0.05 mA / cm2(active area: 4 cm2). The presence of O2 replaces the cathodic HER with ORR, resulting in a lower cell voltage.

[0070] Achieving high-purity LiOH is crucial as it can reduce the need for downstream separation processes. Therefore, impurity concentrations were obtained throughout the electrochemical reaction, using inductively coupled plasma mass spectrometry (ICP-MS). The concentrations of iron and phosphorus remained consistently low, as shown by the Fe and P plots in FIG. 6. The final concentrations show an iron impurity of 0.11 wt.%, a phosphorus impurity of 0.72 wt.% (calculated as PO43'),and an aluminum impurity of 0.2 wt.% relative to LiOH. Additionally, the final pH of the catholyte was measured to be 12.3, corresponding to a lithium concentration of 0.47 mM. These results illustrate a high purity of LiOH and confirm the absence of other significant side reactions during the recycling process.

[0071] The lithium recovery rate was calculated as the lithium amount detected in the catholyte divided by the average initial lithium amount in the LFP electrode, which was quantified using IC after acid leaching with excess sulfuric acid and H2O2, described in more detail below. FIG. 7 illustrates the decline in recovery rates as current density increases. At lower current densities of 0.05 mA / cm2and 0.10 mA / cm2, recovery rates exceeded 95.0%. The recovery rate slightly decreased to 91.0% at 0.50 mA / cm2(-0.2C), and a marked drop to 69.5% was observed at 1.00 mA / cm2. This trend is expected since, in battery charging, the specific capacity of LFP also decreases with increasing charge rates, as fast delithiation rates may induce structural deterioration of LFP, and the side reaction of OER. To ensure the accuracy of lithium concentration measurements on the cathode side and verify the massATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT balance of lithium, the remaining lithium in the electrode after the reaction was also quantified. As illustrated in FIG. 8, the sum of the lithium amount in the catholyte and the lithium amount remaining in the post-reaction electrode approximated the average initial lithium amount in the electrode. Additionally, higher delithiation rates resulted in more residual lithium in the post-reaction LFP, supporting the observation that accelerated delithiation within the range of 0.05 mA / cm2to 1.00 mA / cm2leads to reduced lithium recovery rates. The successful recovery of lithium was also verified through the Time-of-flight secondary ion mass spectrometry (TOF-SIMS) characterization, described in more detail below. The normalized (by the total ion intensity) Li intensity was initially 21.5%, as evidenced by the intensity-depth profile of the electrode, not shown. After extraction, it decreased to below 2.5%, with the surface (facing the CEM) lithium intensity slightly higher than the bulk of the electrode. The normalized intensity of Li and Fe showed uniform distribution on the electrode surface with higher intensity for Fe but lower intensity for Li for the postextraction electrode compared to the pre-extraction electrode, not shown. In summary, with IC quantification and TOE-SIMS characterization, lithium recovery from the LLP electrodes was confirmed.

[0072] The faradic efficiency (PE) Li+in the cathode was calculated using the following Eqn. 1, where CLiis the concentration of Li+(mol / L) measured using IC, ^cathode isthe volume of the catholyte, F is the Faraday constant (96,485 C mol1), t is the reaction time, and jtotai isthe total current (A).

[0073] The FE is directly tied to the energy consumption of the system, with higher FE reflecting higher energy efficiency. However, potential side reactions at the anode, such as the oxygen evolution reaction (OER), can lower the FE of the delithiation process. Despite the absence of anolyte, water in the cathode chamber penetrated the CEM and wetted the LFP electrode surface, where iron acted as an OER catalyst, initiating the competing OER. To gain a deeper understanding of the interaction between OER and LFP delithiation and its impact on lithium FE and recovery rate, the concentrations of O2 on the anode side using gas chromatography (GC) and Li+in the catholyte using ionic chromatography (IC) during the reaction (0.5 mA / cm2, 0.2ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCTC) were monitored. As depicted in FIG. 9, trace amounts of O2 were initially detected during the first 2-hours, while the cell voltage remained relatively constant at around 1.2 V. The cell voltages for the O2, Fe, and P quantification test, not shown, were obtained as follows. For O2 quantification, the cylindrical black mass is coated on a 6.25 cm2gas diffusion layer carbon paper (GDL, Sigracet 28 BC) with a black mass loading of 16.32 mg / cm2. The electrochemical test was conducted at 0.51 mA / cm2(approximately 0.2 C). The O2 generated by OER on the anode side was carried out using Ar with a flow rate of 5 seem, and the O2 concentration was measured by gas chromatography (GC).

[0074] The delithiation reaction continued to dominate, with the Li+concentration steadily increasing, as seen in FIG. 6, showing a Li recovery rate of 97.7% within 5.0 hours. However, by 5.5 hours, OER contributes to 73.3% of the FE and steadily rises to around 86.4% by 6.4 hours, coinciding with a decrease in the FE of Li to below 3.4%. These findings suggest that the side reaction of OER can be mitigated by implementing reasonable cut-off voltages or reaction times based on the delithiation rate while ensuring a high recovery rate. As shown by the dashed line in FIG. 8, distinct cut-off voltages were employed based on the current densities to avoid OER, and the FE remained high across all current densities ranging from 0.05 mA / cm2to 1.00 mA / cm2, consistently surpassing 92.6%, not shown.Example 2 - Black Mass Recycling

[0075] The recycling method was also applied to LFP blackmass (BM) obtained from two battery architectures provided by TotalEnergies: cylindrical and prismatic. To verify the composition of the BM samples, they were characterized using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The XPS results, not shown, revealed the presence of Al and F in the BM, likely originating from aluminum foil brushed down along with the BM and the PVDF binder. XRD analysis, not shown, confirmed that the samples primarily consisted of LFP cathode material, LiFePO4, with minor impurities including FePO4. The lithium content in both samples was quantified using the method described below, where BM was leached with excess H2SO4 and H2O2, followed by analysis of the leachate via IC, see Table 1 below. The cylindrical sample contained 40.5+0.5 mgLi / gBM, indicating that the active material (LFP) accounted for 92.0+1.1 wt.%. Similarly, the prismatic sampleATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT contained 37.6 ± 1.2 mgLi / gBM, suggesting an active material content of 85.4 ± 2.6 wt.%. These quantification results were further validated with TOF-SIMS, not shown, which confirmed that only trace amounts of Li remained in the post-leaching BM. Since the loading of the BM can be accurately measured and calculated, the recovery time was controlled in subsequent BM recovery experiments by assuming 100% energy efficiency based on the loading and delithiation rates, rather than setting different cut-off voltages for various loadings and delithiation rates. This approach ensured consistent conditions across experiments and allowed for better comparisons. The active material mass percentage in Table 1, below, is the percentage of active material (LFP) inside the BM calculated by assuming all the lithium in BM exists in the form of LFP, according to Eqns. 2 and 3 below, where M is the molar mass of lithium and MLFP is the molar mass of LFP.Table 1. IC quantification for LFP BM leached with excess sulfuric acid and H2O2.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT

[0076] The system was further optimized by investigating the effects of loading and delithiation speed on electrical and recovery performance, focusing on the cylindrical BM samples. Higher loadings increased the amount of BM recycled per batch. However, due to the low conductivity of LFP, higher mass loadings resulted in increased resistance and, consequently, higher cell voltage. At a constant delithiation speed (0.2 C), lower loadings exhibited a lower initial cell voltage, as shown in FIG. 10. When the loading decreased below 3.3 mg / cm2, the initial voltage was lower; however, the cell voltage increased more rapidly compared to higher loadings. The recovery rates for different loadings and delithiation speeds (0.1 C, 0.2 C, and 0.4 C) were shown in FIG. 11. For low loadings (2.0 mg / cm2and 3.3 mg / cm2), although the recovery rate was high at 0.2 C, it was relatively low at 0.1 C and 0.4 C. The low recovery rate and the sharp increase in cell voltage at low loadings can be explained by the fact that a larger proportion of the BM sample is wetted, leading to other competing side reactions. Conversely, for higher loadings (14.0 mg / cm2and 18.0 mg / cm2), the recovery rate remained consistently high across all delithiation speeds from 0.1 C to 0.4 C (1.13 mA / cm2for 18.0 mg / cm2), as a smaller proportion of the electrode is wetted, ensuring better recovery efficiencies. In addition, at the same loading of 6 mg / cm2, higher delithiation rates were observed to decrease the recovery rate, not shown. When the delithiation rate was further increased to 1.0 C (extraction time: 1.0 h), the recovery rate dropped to 85.1%, with a faradaic efficiency (FE) of 74.8%. This trade-off between faster delithiation rates and reduced recovery rates, as well as lower energy efficiency, is primarily attributed to the onset of side reactions, such as OER. As discussed below, the OER can be mitigated by employing the PTFE- reinforced CEM, and a recovery rate of 93.5% can be achieve with an FE of 83.5%, albeit at a higher cell voltage of 1.0 C, not shown. For a balance between energy efficiency and lithium recovery, the delithiation rate was set at 0.2 C and the loading at approximately 14 mg / cm2(average cell voltage: 1.5 V, recovery rate: 94.2%) for subsequent calculations and experiments for the cylindrical sample.

[0077] When the BM was directly coated from prismatic batteries onto the currentATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT collector (5.5 mg / cm2), the cell voltage started at a high value (> 1.5 V), it continued to increase sharply, and reached the protection cell voltage of 5.0 V, shown in FIG. 12. Comparing the Energy-dispersive X-ray spectroscopy (EDX) mapping results of the cylindrical BM sample and the prismatic BM sample, both spray-coated onto 30 pm thick Al foil with an approximate loading of 6 mg / cm2, not shown, the carbon intensity in the cylindrical sample is much higher than that of the prismatic sample. The high cell voltage of the prismatic sample may be a result of insufficient conductive carbon in the prismatic BM sample. To test this, different amounts of conductive carbon (2.0 wt.%, 5.0 wt.%, and 10.0 wt.%) were mixed with the BM sample, applied to a non-conductive glass substrate (to avoid the influence of a conductive substrate on the resistivity test), and measured the resistivity using a four- point probe, see details below. As shown in FIG. 13 and Table 2, below, the resistivity of the original prismatic BM sample was 1791.2 Q-m. The resistivity significantly decreased to 43.4 Q-m with the addition of only 2.0 wt.% conductive carbon and further decreased to 0.4 Q-m with the addition of 5.0 wt.% conductive carbon. These resistivity results were consistent with the cell voltage in FIG. 12, confirming that the addition of 5.0 wt.% conductive carbon significantly reduced the cell voltage. FIG. 14 shows the FE and the recovery rate of Li for the prismatic BM with different amounts of conductive carbon at a delithiation rate of 0.2 C and a protection cell voltage set at 5.0 V. The FE remained high across all cases; however, without conductive carbon or with only 2.0 wt.% added, the cell voltages increased rapidly, reaching 5.0 V before all the lithium in the BM could be recovered, resulting in low recovery rates. Conversely, the recovery rate increased to approximately 96.2% when more than 5.0 wt.% conductive carbon was added. Therefore, it was confirmed that adding sufficient conductive carbon can reduce the resistivity of the BM and subsequently lower the cell voltage, ensuring high FE and recovery rates for the recycling of prismatic LFP batteries.Table 2. The sheet resistance measured using the 4-point-probe, the resistivity, and the resistance of the 4 cm2BM coating with 0.08 mm thickness for the prismatic BM with different amounts of conductive carbon.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT

[0078] The resistivity of the prismatic BM was measured as follows. The resistivity was measured using a Jandel RM3 4-point probe system. The BM (loading: 2 mg / cm2) was spray-coated onto a 2-inch x 2-inch x 150 pm electrically insulating glass substrate to prevent parallel conduction paths. The probe had a 1 mm spacing between tungsten carbide tips (50 pm tip diameter), and measurements were taken at the center of the glass sheet to minimize edge effects. The thickness of the coating, 0.08 mm, can be calculated according to Eqn. 4, below.ThicknessBM=Thicknesstotai - ThicknessgiaSs Eqn. 4

[0079] The resistivity of the BM was calculated using the sheet resistance measured using the 4-point probe, according to Eqn. 5 below. p=RsxThicknessBMEqn. 5

[0080] The resistance of the 0.08 mm BM coating on a 4 cm2substrate can then be calculated according to Eqn. 6, below. See Table 2 above for the results._ ThicknessRMR= P — A ; -rea Eqn. 6Example 3 - Long Term Stability and Scale Up

[0081] To align with industrial applications and demonstrate scalability, the active reaction area was expanded to 20 cm2and stability testing was conducted using the cylindrical BM sample. FIG. 15 illustrates the recovery system, which includes three steps. First, the BM from the used battery was applied to a Ti current collector plate, see FIG. 16 (top right and left), and prepared for the subsequent recovery process. FIG. 16 shows the Ti current collector plate (top left), the Ti current collector plate after application of the BM (top right), the Ti current collector plate with BM afterATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT electrolysis (bottom left), and the Ti current collector plate with the electrolyzed BM scrapped off (bottom right). Subsequently, lithium in the BM was extracted as LiOH to the catholyte (30 or 40 mL of DI water) with the 20-cm2electrochemical reactor. Finally, in the post-reaction processing, the BM on the electrode (FIG. 16, bottom left) was washed to remove surface LiOH, the post-reaction BM (FePO4 and conductive carbon) was collected as the product (FIG. 16, bottom right), and the Ti current collector was prepared for reuse in the first step. FIG. 17 shows a photo, left, of the post-reaction BM after 10 cycles, which appears as a black powder, with its XRD patterns matching the standard FePO4 (FIG. 18). FIG. 17 also shows a photo, right, of the LiOH product (from 2 cycles) after freeze-drying, which appears as a white poweder, with XRD patterns indicating it matched standard LiOH H2O (FIG. 18). In summary, 28.1 g of cylindrical BM was recycled, with an average recovery rate of 91.1% for LiOH and an average post-reaction BM yield of 97.0% for FePO4.

[0082] The BM electrode was prepared as follows. For the 20-cm2reactor, 380 mg of cylindrical BM and 72 pL of Nafion solution were mixed with 0.8 mL of 2-proponal, after mixing for 3 min and doctor blade to the current collector. The exact loading of the black mass on the current collector was determined by measuring the mass of the current collector before and after coating.

[0083] The stability test was performed at a delithiation speed of 0.21 C (approximately 6.2 mA) with a reaction time of 5 hours to ensure high recovery rates, albeit with slight sacrifices in FE. As shown in FIG. 19, the cell voltage remained very stable, with a plateau of every cycle maintained at around 1.5 V over the 500-hour operation. The recovery rate was high for every odd-numbered cycle (averaging 95.7%) but slightly lower for every even-numbered cycle (averaging 86.4%) and decreased every 10 cycles (averaging 69.2%) due to the procedural design, as shown in FIG. 20. Specifically, the catholyte was replaced with DI water every 2 cycles, and the membrane was regenerated every 10 cycles due to color changes, not shown. To further confirm that the color change of the CEM was caused by Fe3+deposits, the CEM was regenerated using 200 mL of 0.05 M H2SO4 at 70°C, and the discoloration occurred within 10 minutes. The 200 mL solution was then analyzed using ICP-MS. The solution contained 24 ppm of Li, aligning well with the observed loss of Li+during the first cycle after activation. Additionally, it contained 4.6 ppm of P and 7.4ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT ppm of Fe. Furthermore, no color change was observed when the CEM was used with LiCl or L12SO4 flowing in the anolyte without water splitting. These results confirm that the color change of the CEM was not due to the replacement of H+with Li+in the membrane. During even-numbered cycles, since the catholyte was not refreshed, the high LiOH concentration in the catholyte (FIG. 16, bottom right) promoted OER, reducing the lithium recovery rate. Additionally, H+ions replaced Li+ions in the membrane during regeneration. Therefore, every 10 cycles, the membrane had to be re- saturated with Li+ions before they could be released into the catholyte, resulting in lower recovery rates. This challenge can be addressed by employing a more hydrophobic and selective membrane.Example 4 - Roll-to-Roll Reactor

[0084] This example demonstrates a semi-continuous roll-to-roll reactor system for recovering lithium from spent battery materials, exemplifying a roll-to-roll reactor system as illustrated in FIG. 2. FIG.s 21 and 22 illustrate an exemplary roll-to-roll reactor system. FIG. 2 shows a schematic of the roll-to-roll reactor system. FIG. 21 shows a top view of an exemplary roll-to-roll reactor system. FIG. 22 shows a side view of the exemplary roll-to-roll reactor system. For the exemplary roll-to-roll reactor, a 20 cm2roll-to-roll design was used. For the exemplary roll-to-roll reactor, the cathode electrode (coated on Al foil) to be recycled was placed on the anode side, while Ni foam was chosen as the catalyst alkaline hydrogen evolution reaction (HER) for its excellent stability, sufficient activity under low current density, and low cost Nafion was used as a stable and robust cation exchange membrane. The de-lithiation of cathode material released Li+, and the Li+was transported through the cation exchange membrane to couple with the OH- generated by HER and form LiOH.

[0085] As depicted in FIG. 2, the LFP cathode is initially wound around an unwinder. After recycling one segment, both the unwinder and the rewinder rotate, moving the next LFP segment to the reaction area while the post-reaction electrode winds onto the rewinder. FIG.s 23 and 24 show the recovery performances of the roll-to-roll device, operating at 0.50 mA / cm2(-0.2C, active area: 20 cm2), with a cut-off voltage set at 2.2 V. The cell voltage remained stable and low, with a plateau at around 1.3 V for each cycle. A high FE (averaging 83.4%) and a high recovery rate (averaging 90.0%) was achieved, except for the first cycle where the membrane was beingATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT activated. However, as mentioned previously, since the catholyte was refreshed every 2 cycles, the FE was lower for every even-numbered cycle. Both the BM and the electrode recovery results indicated that the side reaction of OER, promoted by the high OH concentration, limited the reactors ability to achieve higher LiOH concentrations while maintaining high FE and recovery rates.

[0086] To address this, a PTFE-reinforced selective CEM was employed. The hydrophobic PTFE coating makes the membrane more selective to more hydrophobic cations (Li+and Na+) compared to H+. The H+generated by OER is less likely to be transported through the membrane. The H+is concentrated at the membrane surface, thus suppressing OER. Additionally, the hydrophobic coating reduces water transport through the membrane, which not only prevents OER but also mitigates the hydrolysis of FePO4. A brownish color on the PTFE-reinforced CEM (after 15 cycles) was observed, and was much lighter than on the normal CEM (after 10 cycles), not shown. FIG.s 25 and 26 show the recovery performances using the PTFE-reinforced CEM. Although the cell voltage was around 0.1 V higher than that with the normal CEM, a high FE of 96.6% and a recovery rate of 96.4% was achieved, even when the Li+concentration exceeded 1500 ppm (0.22 M).

[0087] To achieve a higher concentration of LiOH, which can be beneficial for subsequent water evaporation or precipitation processes, the 30 mL catholyte was recycled for 26 cycles, concentrating the LiOH to 0.98 M. However, the plateau of the cell voltages became less stable, and the FE decreased from an average of 92.8% for the initial 10 cycles to 64.1% by the 26th cycle, as shown in FIG.s 27 and 28.Example 5 - Other Battery Cathode Materials

[0088] The recycling method and reactor system was applied to other cathode materials, such as LiMn2O4 (LMO) and LiNio.5Mno.3Coo.2O2 (NMC532) electrodes. At a delithiation speed of 0.2 C (0.45 mA / cm2), the cell voltage plateaus of LMO and NMC532 were higher than that of LFP due to the intrinsic higher delithiation potentials of LMO and NMC532, not shown. Using the PTFE-reinforced CEM to suppress OER, the FE remained high at 88.2% for LMO recycling and 93.6% for NMC532 recycling, with final lithium recovery rates of 94.0% for LMO and 93.6% for NMC532, not shown. In addition to LMO and NMC532, the method was appliedATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT to a hybrid cathode material comprising LiCoCri and LFP, achieving a recovery rate of 90.6% with an average FE of 90.8%, not shown.

[0089] The cell voltage profile for lithium recovery from a mixture of cylindrical BM and LCO in a 1:1 ratio was obtained. The lithium recovery test using hybrid (composite) cathode materials composed of LFP and LCO was as follows. The cylindrical BM sample (LLP as the active material) was mixed with LCO powder in a 1:1 ratio, coated onto a titanium plate (20 cm2active area), and the Li recovery test was performed using a PTEE-reinforced CEM under a current density of 2.2 mA / cm2(0.2C). The cell voltage was slightly higher compared to tests using only cylindrical BM, starting at approximately 1.2 V and increasing to around 2.5 V after 5 hours. The average EE remained high at 90.8% during the 5-hour reaction time, with the lithium recovery rate rising, reaching approximately 90.6% after 5 hours of extraction.Lithium Recovery Rate and TOF-SIMS

[0090] The lithium recovery rates were calculated for all Examples as follows. The amount of lithium in the BM and commercial cathode samples was quantified using a conventional hydrometallurgy method using excessive sulfuric acid and H2O2. In conventional hydrometallurgical recovery process, the quantities of H2SO4 and H2O2 must be precisely controlled to ensure that Li is selectively dissolved while Fe remains in the solid state as FePCL. Optimal leaching of 96.85% of lithium from LFP requires H2SO4 and H2O2 to be added at molar ratios of 0.57 and 2.07, respectively, relative to LFP. In the quantification step, excess amounts of H2SO4 (four times the recommended quantity) and H2O2 (twice the recommended quantity) were added to ensure complete dissolution of lithium for accurate analysis. Specifically, the BM (around 50 mg) and commercial cathode (4 cm2, cut into 0.25cm2small pieces) were sonicated in 10 mL y dissolve) DI water for 60 min, mixed with 50 pL of 98% sulfuric acid and 400 pL of 30% H2O2, and heated to 70°C for 120 min. The lithium concentration was then tested using IC and ICP-MS. Several BM (and commercial electrode) samples were leached, the lithium amount was tested and took the average (Ci.i_average dissolve)- The recovery is calculated according to Eqn. 7, below and the results can be seen in Table 3, below.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCTTable 3. ICP-MS quantification for LFP BM leached with excess sulfuric acid and H2O2.

[0091] TOF-SIMS measurement was performed using a TOF-SIMS NCS instrument, which combines a TOF.SIMS instrument (ION-TOF GmbH, Munster, Germany) and an in-situ Scanning Probe Microscope (NanoScan, Switzerland). A bunched 30 keV Bi3+ions (with a measured current of 0.15 pA) was used as the primary probe for analysis (scanned area 250 x 250 pm2) with a raster of 256x256 pixels. A charge compensation with an electron flood gun has been applied during the analysis. An adjustment of the charge effects has been operated using appropriate surface potential and adapted extraction bias depending on the analysis area and the polarity. The cycle time was fixed to 100 ps (corresponding to m / z = 0 - 911 a.m.u mass range). The primary ion dose density has been limited to 1.1012ions / cm2to preserve the analyzed surface. Depth profiling have been performed to map out the different samples to characterize the in-depth chemical distribution of the element ions of interest. The primary probe for depth profiling had a field of view of 150x150 pm2, with a raster of 64x64 pixels and then the sputtering was performed using Cs+ions at 2 keV with a typical current around 105 nA, raster area 500x500 pm2. The beams were operated in non-interlaced mode, alternating 1 analysis cycle and 5 sputtering cycles (corresponding to 7.5 s) followed by a pause of 3 s for the charge compensation with an electron flood gun. Again, an adjustment of the charge effects has been operated using a surface potential. During the depth profiling, the cycle time was fixed to 90ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCTILLS (corresponding to m / z = 0 - 738 a.m.u mass range). All of the data have been treated and extracted using SurfaceLab 7.3. Ion signals from spectra and from ion mappings have been normalized using the total ion signal to standardize the values and to help for the comparison between the different samples or the area.Cost Analysis and Energy Requirements

[0092] An approximate calculation of the energy required by the electrochemical reactor for lithium extraction from black mass or a used LFP cathode is the following. The energy consumption of electrolysis was 536 kJ / kgBM (6 mg / cm2and 0.1 C), which was 75.5% lower than the energy consumption of the hydrometallurgy method (2 X 103kJ / kgBM, excluding pretreatment and post-treatment steps). The overall energy consumption of the system was 5.75xl03kJ / kgBM, post-treatment (crystallization and evaporation) accounts for 89.0%. Similarly, CO2 emissions from the post- treatment step accounted for 70.8% of the total CO2 emissions. In contrast, CO2 emission from the electrolysis step was reduced to 58.0 g CCh / kguv. In summary, the system and method disclosed herein require significantly lowered the energy consumption and carbon footprint of the lithium extraction (electrolysis) steps. A total energy consumption for a method for recovering battery material from a used battery may include energy consumption by equipment used in the method such as an evaporator, filter, and coater. The total energy consumption may be determined by known methods by one of ordinary skill in the art based on specifications of the equipment.

[0093] Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

Claims

ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCTCLAIMSWhat is claimed:

1. A method for recovering used battery material from a used battery, the method comprising: providing a solid-state anode reactant comprising the used battery material; placing the solid-state anode reactant between an anode current collector and a cation exchange membrane in an electrochemical reactor, wherein the electrochemical reactor comprises: a cathode compartment comprising a cathode current collector and a cathode catalyst; an anode compartment comprising the anode current collector and the solid-state anode reactant; the cation exchange membrane, wherein the cation exchange membrane is disposed between the cathode compartment and the anode compartment; a feed stream fluidly connected to the cathode compartment; and a product stream fluidly connected to the cathode compartment; applying a voltage to the electrochemical reactor; and collecting a recovered material from the product stream.

2. The method of claim 1, wherein the used battery material comprises a substance selected from the group consisting of LiFePCU, LiM CU, NMC’s, and black mass.

3. The method of any one of claims 1 or 2, wherein the recovered material comprises lithium hydroxide.

4. The method of any one of the preceding claims, wherein the cathode catalyst is a reduction catalyst capable of catalyzing the four-electron oxygen reduction reaction or the hydrogen evolution reaction.

5. The method of any one of the preceding claims, wherein the cation exchange membrane is selected from the group consisting of Nafion™ and Nafion™ with a hydrophobic coating.ATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT6. The method of any one of the preceding claims, wherein the feed stream comprises water.

7. The method of claim 6, wherein the feed stream further comprises LiOH.

8. The method of any one of the preceding claims, wherein the method recovers at least a portion of a metal in the used battery material from the solid-state anode reactant.

9. The method of claim 8, wherein the metal comprises lithium.

10. The method of any one of the preceding claims, wherein: a roll-to-roll reactor system comprises: the electrochemical reactor; an unwinder; a rewinder; and a used battery cathode electrode rolled on the unwinder and rewinder and passing through the electrochemical reactor, wherein within the electrochemical reactor, the used battery cathode is the solid-state anode reactant; and the method further comprises, once at least a portion of a metal in the used battery material is recovered from a section of the used battery cathode electrode disposed within the electrochemical reactor, rotating the unwinder and rewinder such that another segment of the electrode is disposed with the electrochemical reactor.

11. An electrochemical reactor for recovering used battery material from a used battery, the electrochemical reactor comprising: a cathode compartment comprising a cathode current collector and a cathode catalyst; an anode compartment comprising an anode current collector and a solid-state anode reactant; a cation exchange membrane disposed between the cathode compartment and the anode compartment; a feed stream fluidly connected to the cathode compartment; and a product stream fluidly connected to the cathode compartment; wherein the solid-state anode reactant comprises the used battery material; andATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT wherein the product stream comprises a recovered material.

12. The electrochemical reactor of claim 11, wherein the used battery material comprises a substance selected from the group consisting of LiFePC , LiM C , NMC’s, and black mass.

13. The electrochemical reactor of any one of claims 11 or 12, wherein the recovered material comprises lithium hydroxide.

14. The electrochemical reactor of any one of claims 11-13, wherein the cathode catalyst is a reduction catalyst capable of catalyzing the four-electron oxygen reduction reaction or the hydrogen evolution reaction.

15. The electrochemical reactor of any one of claims 11-14, wherein the cation exchange membrane is selected from the group consisting of Nafion™ and Nafion™ with a hydrophobic coating.

16. The electrochemical reactor of any one of claims 11-15, wherein the feed stream comprises water.

17. The electrochemical reactor of claim 16, wherein the feed stream further comprises LiOH.

18. The electrochemical reactor of any one of claims 11-17, wherein at least a portion of a metal in the used battery material is recovered from the solid-state anode reactant.

19. The electrochemical reactor of claim 18, wherein the metal comprises lithium.

20. A roll-to-roll reactor system for recovering used battery material from a used battery, the roll-to-roll reactor comprising: the electrochemical reactor of any one of claims 11-19; an unwinder; a rewinder; and and a used battery cathode electrode rolled on the unwinder and rewinder and passing through the electrochemical reactor of any one of claims 11-19, whereinATTORNEY DOCKET NO. 17500-270W01CLIENT REF. NO. 2024-088-PCT within the electrochemical reactor of any one of claims 11-19, the used battery cathode electrode is the solid-state anode reactant.

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