Electroproduction of alkali metal hydroxides and sulfuric acid from battery manufacturing and recycling outlet streams

Abstract

A method for producing sodium hydroxide (NaOH) or lithium hydroxide (LiOH) and sulfuric acid (HSO) includes producing sodium sulfate (NaSO) or lithium sulfate (LiSO) from battery manufacturing and recycling, and converting the produced NaSO or LiSO to NaOH, LiOH, and HSO via an electrochemical salt decomposition process. The processing step can be carried out in a closed system so that the produced NaSO or LiSO can be used in the conversion step, along with optional purification steps. In particular, the LiOH, NaOH, and NaSO are recycled to the battery recycling or battery manufacturing process.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 409,167, filed September 22, 2022. The foregoing application is incorporated herein by reference in its entirety.

[0002] The present invention relates generally to chemical production and recycling, and more particularly to the production of alkali metal hydroxides and sulfuric acid from outlet streams of battery manufacturing and recycling. [Background technology]

[0003] Sodium hydroxide (NaOH), lithium hydroxide (LiOH), and sulfuric acid (H2SO4), to name a few, are important commodity chemicals with extensive use across the chemical, pharmaceutical, energy, paper and pulp, and water industries. For example, NaOH is widely used in the manufacture of other chemicals due to its basicity, LiOH is consumed in the production of cathode active materials for battery applications, and H2SO4 is heavily used in the production of phosphate-based fertilizers.

[0004] Existing technologies for producing NaOH, LiOH, and H2SO4 are either process-intensive or produce additional chemicals with hazardous concerns. For example, high-purity NaOH is primarily produced from brine using the chlor-alkali process, which produces harmful chlorine gas (Cl2). In some examples, the production of LiOH can involve the extraction and purification of lithium carbonate (Li2CO3) from chloride-containing lithium minerals. For example, lithium chloride (LiCl) can be converted to Li2CO3 using sodium carbonate (Na2CO3), which can then be further converted to LiOH using calcium hydroxide (Ca(OH)2), all starting from brine. In other examples, the production of LiOH can occur by converting mineral-derived lithium sulfate (Li2SO4) to LiOH using NaOH. Finally, the production of H2SO4 can consist of multiple steps, including the extraction and conversion of sulfur (S) to sulfur dioxide (SO2) through purification techniques, the high-temperature catalytic conversion of SO2 to sulfur trioxide (SO3), and the subsequent conversion of SO3 to H2SO4 with water. Summary of the Invention

[0005] One or more embodiments of the present disclosure include systems and methods for producing one or more of NaOH, LiOH, or H2SO4 via electrochemical salt decomposition. For example, one or more embodiments utilize an outlet stream from a lithium-ion battery manufacturing or recycling process to produce sodium (Na + ) or lithium (Li + ) cation, and sulfate anion (SO4 2 ). Such an embodiment includes producing sodium (Na + ) or lithium (Li + ) cation, and sulfate anion (SO4 2- ) undergoes electrochemical salt decomposition to produce one or more of NaOH, LiOH, or H2SO4.

[0006] For example, one or more embodiments include a method for producing NaSO from a battery manufacturing process. The method further includes converting the produced NaSO to NaOH and HSO via an electrochemical salt decomposition process. For example, the method includes electrochemical salt decomposition of NaSO utilizing an electrochemical cell having two or more compartments separated by one or more ion exchange membranes. Furthermore, the method optionally includes converting the produced NaSO to NaOH and HSO without one or more purification techniques required by conventional industrial processes.

[0007] Another embodiment includes a method for producing LiSO from a battery recycling process. The method further includes converting the produced LiSO to LiOH and HSO via an electrochemical salt decomposition process. For example, the method includes electrochemically salt decomposing LiSO using an electrochemical cell having two or more compartments separated by one or more ion exchange membranes. Furthermore, the method optionally includes converting the produced LiSO to LiOH and HSO without one or more purification techniques required by conventional industrial processes.

[0008] Additional features and advantages of one or more embodiments of the present disclosure will be set forth in the description that follows, and in part may be determined from the description, or may be learned by practice of such exemplary embodiments. [Brief explanation of the drawings]

[0009] The present disclosure describes one or more embodiments of the invention with additional specificity and detail by reference to the accompanying drawings. The following paragraphs briefly describe these drawings:

[0010] [Figure 1] FIG. 1 shows a process diagram for producing sodium sulfate (NaSO) from a battery manufacturing process, according to one or more embodiments.

[0011] [Figure 2] FIG. 2 shows a process diagram for converting Na2SO4 to sodium hydroxide (NaOH) and sulfuric acid (H2SO4) via an electrochemical salt decomposition process, according to one or more embodiments.

[0012] [Figure 3] FIG. 3 shows a process diagram for producing lithium sulfate (LiSO) from a battery recycling process, according to one or more embodiments.

[0013] [Figure 4] FIG. 4 shows a process diagram for converting Li2SO4 to lithium hydroxide (LiOH) and sulfuric acid (H2SO4) via an electrochemical salt decomposition process, according to one or more embodiments.

[0014] [Figure 5] FIG. 5 illustrates the conversion of Na2SO4 to NaOH and H2SO4 via a salt splitting process using two- and three-compartment electrolysis cells, according to one or more embodiments.

[0015] [Figure 6] FIG. 6 illustrates the conversion of Li2SO4 to LiOH and H2SO4 via a salt decomposition process using two- and three-compartment electrolysis cells, according to one or more embodiments.

[0016] [Figure 7] FIG. 7 illustrates the conversion of Li2SO4 to LiOH and H2SO4 via a salt splitting process using a three-compartment bipolar membrane electrodialysis cell according to one or more embodiments.

[0017] [Figure 8] FIG. 8 illustrates the conversion of Na2SO4 to NaOH and H2SO4 via a salt splitting process using a three-compartment bipolar membrane electrodialysis cell according to one or more embodiments.

[0018] [Figure 9] , [Figure 10] 9 and 10 show the conversion of Li2SO4 to LiOH and H2SO4 via a salt splitting process using a two-compartment bipolar membrane electrodialysis cell according to one or more embodiments.

[0019] [Figure 11] FIG. 11 shows a flowchart of a series of operations for generating Na2SO4 from battery production and converting it to NaOH and H2SO4 via an electrochemical salt decomposition process, according to one or more embodiments.

[0020] [Figure 12] FIG. 12 shows a flowchart of a series of operations for producing Li2SO4 from battery recycle and converting it to LiOH and H2SO4 via an electrochemical salt decomposition process, according to one or more embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0021] This disclosure describes one or more embodiments of methods and systems for producing Na2SO4 and Li2SO4 from battery manufacturing and recycling processes, respectively, and combining the Na2SO4 and Li2SO4 with H2SO4 to convert them to NaOH and LiOH, respectively. For example, in some embodiments, the disclosed systems and methods employ an electrochemical cell having two or more compartments separated by one or more ion exchange membranes to electrochemically decompose the Na2SO4 or Li2SO4 outlet stream from battery manufacturing and recycling in an aqueous solution and combine it with H2SO4 to produce NaOH or LiOH. The ion exchange membranes are used to convert alkali metal cations or SO4 2- In one or more embodiments, the electrochemical salt decomposition process includes electrolysis using an oxygen-depolarized cathode, electrolysis using a hydrogen-depolarized anode, electrolysis using a dimensionally stable anode, or bipolar membrane electrodialysis.

[0022] In one or more embodiments, the system utilizes electrolysis or bipolar membrane electrodialysis for these salt decomposition processes. Additionally, in one or more embodiments, an electrochemical salt decomposition process can include bipolar membrane electrodialysis in combination with HSO to convert NaSO or LiSO to NaOH or LiOH, respectively. In electrolysis, the anodic and cathodic reactions produce protons (H + ) and hydroxide (OH - ), which can produce H2SO4 and NaOH, or H2SO4 and LiOH, which can accumulate in the anolyte and catholyte, respectively. In bipolar membrane electrodialysis, a bipolar ion exchange membrane is used to separate H2SO4 from the catholyte, rather than the anodic and cathodic reactions. + and OH - It is the main source of

[0023] For example, one or more embodiments include a method of producing NaSO from a battery manufacturing process. The method further includes converting the produced NaSO to NaOH and HSO via an electrochemical salt decomposition process. For example, the method includes electrochemically salt decomposing the NaSO using an electrochemical cell having two or more compartments separated by one or more ion exchange membranes.

[0024] In one or more embodiments, the method includes producing NaSO and converting the produced NaSO to NaOH and HSO in a closed system. In other words, once NaSO is produced from an outlet stream of a battery manufacturing process, the method includes introducing the outlet stream into an electrochemical cell in situ (e.g., locally or on-site) for a salt decomposition process in a closed-loop system (e.g., an integrated plant including battery material production and recycling by electrolysis). Some embodiments include returning and reintroducing the resulting products, i.e., NaOH and HSO, from the electrochemical salt decomposition process into the battery manufacturing and recycling process.

[0025] Additionally, some embodiments include controlling the concentration and purity upstream of the synthesis of the precursor cathode active material (pCAM) in conjunction with the conversion of NaSO to HSO and NaOH. Additionally or alternatively, the method includes utilizing high-purity water to control impurities. By controlling inputs and impurities, the system can eliminate one or more purification steps required by most industrial electrochemical salt decomposition technologies, as described in more detail below.

[0026] Another embodiment includes a method for producing LiSO from a battery recycling process. The method further includes converting the produced LiSO to LiOH and HSO via an electrochemical salt decomposition process. For example, the method includes electrochemically salting the LiSO utilizing an electrochemical cell having two or more compartments separated by one or more ion exchange membranes.

[0027] Further, some embodiments include producing LiSO and converting the produced LiSO to LiOH and HSO in a closed or closed-loop system. In other words, once LiSO is produced from the outlet stream of the battery recycling process, the method includes introducing the outlet stream into an electrochemical cell in situ (e.g., locally or on-site) in a closed or closed-loop system for a salt decomposition process. Similarly, some embodiments include returning and reintroducing the resulting products, i.e., LiOH and HSO, to the battery manufacturing and recycling process. Furthermore, one or more embodiments can include managing the concentration and purity of inputs in the recycling of battery materials during the battery recycling process, which can result in the elimination or streamlining of downstream purification and processing steps when converting LiSO to LiOH and HSO.

[0028] Recently, the electrochemical desalination of alkali metal sulfates to produce their component hydroxides and acids has gained interest as a modular platform for producing these chemicals. However, there are technical challenges associated with impurities present in battery manufacturing and recycling streams, which can foul anodes, cathodes, and membranes, resulting in increased cell resistance, loss of current efficiency, and increased downtime for replacing these components, resulting in higher costs and lower productivity. Furthermore, there are technical challenges associated with generating contaminated acid streams, as contaminated acids are not commercially fungible products.

[0029] In fact, conventional industrial techniques often require many purification steps, including: (1) starting with a solution of NaCl or brine, (2) dissolving or preparing the solution into a concentrated brine, (3) scrubbing the brine of any organic matter or solid particulates (e.g., microorganisms, algae, dust) via ultrafiltration, (4) initial hardness removal via carbonation using CO2 or soda ash, caustic soda (NaOH), CaCl2, or Ba(OH)2 to remove Ca, Mg, and SO4, (5) filtration and removal of solid precipitates, often via candle filters or other filtering processes, (6) further removal of Ca and Mg in IX purification steps, (7) evaporation to concentrate the brine to near saturation, and (8) adjusting the pH to the target pH (pH = 7).

[0030] Additionally, interest in the electrochemical salt decomposition of sodium sulfate (NaSO) (as well as lithium sulfate (LiSO)) stems from recent macro trends that are creating challenges to the dumping or sale of NaSO, including, by way of non-limiting example, increased production of NaSO due to the rapid growth of the battery industry driven by the introduction of electric vehicles, a global shift away from powdered cleaning agents as the largest end market for NaSO, and increased global scrutiny and environmental impact / regulations restricting the dumping of NaSO into rivers, lakes, and oceans and restricting the sale of NaSO across borders.

[0031] Advantages of the disclosed systems and methods include, by way of example and not limitation, the elimination of one or more purification steps of the NaSO or LiSO outlet streams from battery manufacturing and recycling required by industrial electrochemical salt decomposition techniques to remove unwanted metal impurities, as described in more detail below. Additionally, the disclosed systems allow these outlet streams to be highly enriched with NaSO and LiSO, providing improved production rates and process enhancements by electrochemically co-producing NaOH or LiOH with HSO.

[0032] More specifically, in some embodiments, a method for producing Na2SO4 can include controlling the concentration and purity of inputs in the synthesis of precursor cathode active material (pCAM), which can result in the elimination of several purification steps when converting Na2SO4 to NaOH and H2SO4. Similarly, one or more embodiments can include controlling the concentration and purity of inputs in the processing of recycled battery materials during a battery recycling process, which can result in the elimination or streamlining of downstream purification and processing steps when converting Li2SO4 to LiOH and H2SO4.

[0033] Similarly, in some embodiments, a method for producing LiSO and converting LiSO to LiOH and HSO can include controlling the concentration and purity of inputs in the process of recycling battery materials during a battery recycling process, for example, by controlling the raw materials and reagents used. Additionally, in some embodiments, the method can include controlling impurities by utilizing high-purity water. Indeed, by controlling inputs and impurities, the system can eliminate several purification steps and streamline processes, such as crystallization techniques, saving capital and operating expenses and simplifying processes, as described in more detail below.

[0034] Reference is made to FIG. 1 , which illustrates a process diagram for producing sodium sulfate (NaSO) from a battery manufacturing process 100 according to one or more embodiments. In one or more embodiments, the battery manufacturing process 100 can produce NaSO as a by-product from the synthesis of a precursor cathode active material (pCAM). For example, in one embodiment, the battery manufacturing process 100 includes synthesizing a metal hydroxide (M(OH)), known as pCAM, using a pCAM reactor 102. In some embodiments, the battery manufacturing process 100 can react a metal sulfate (M(SO)), which can be an individual metal sulfate (e.g., NiSO, CoSO, MnSO) or a mixture of metal sulfates, with sodium hydroxide (NaOH) in the presence of ammonium hydroxide (NHOH). In these or other embodiments, the battery manufacturing process 100 can use NaOH as a precipitant while using NHOH as a chelating agent to control the precipitation reaction. The overall precipitation reaction is as described in equation (1) below: M(SO4) (aq) + 2NaOH (aq) → M(OH)2 (S) + Na2SO4 (aq) (1)

[0035] In some embodiments, as shown in equation (1), the battery manufacturing process 100 can precipitate M(OH) solids while producing NaSO as a by-product. In one or more embodiments, the battery manufacturing process 100 can pass this aqueous by-product stream containing NaSO through an ammonia recovery process 104 to remove valuable ammonia (NH) as an NHOH solution, which the battery manufacturing process 100 can then recycle back to the plant for pCAM production. In some embodiments, the battery manufacturing process 100 can produce a NaSO solution 106 after ammonia recovery 104 having the specifications shown in Table 1. TIFF2025533551000002.tif51126Table 1. Composition of sodium sulfate solution.

[0036] While the Na2SO4 solution 106 may have the composition as shown above, it will be understood by those skilled in the art that the Na2SO4 solution 106 may have other compositions or concentrations depending on the process step.

[0037] In some embodiments, the battery manufacturing process 100 can produce a Na2SO4 solution 106 having a low impurity concentration from the battery manufacturing process 100. Indeed, the battery manufacturing process 100 can produce a Na2SO4 solution 106 in which the concentration of at least some of the impurities in the solution is less than 20 parts per million (ppm). The produced Na2SO4 solution 106 contains nickel ions (Ni 2+ ), cobalt ions (Co 2+ ), manganese ions (Mn 2+ ), aluminum ions (Al 3+ ), potassium ions (K + ), calcium ions (Ca 2+ ), magnesium ions (Mg 2+ ), chloride ions (Cl - ), or fluorine ion (F - In some embodiments, the system may include various methods for minimizing the concentration of these impurities in the NaSO solution 106 produced from the battery manufacturing process.

[0038] For example, a method for minimizing the concentration of impurities in the produced NaSO solution 106 can include managing the inputs of the battery manufacturing process 100. For example, conventional battery manufacturing systems typically utilize municipally supplied water that is treated by reverse osmosis, a process that results in a certain amount of the above-mentioned impurities in the product stream, such as the NaSO solution 106. While this level of purity is acceptable in conventional manufacturing systems, it is typically not acceptable in electrochemical salt decomposition processes. In contrast, one or more embodiments can include utilizing deionized water in the battery manufacturing process 100 as a method for minimizing the introduction of impurities. Furthermore, many of the reagents and raw materials utilized in battery manufacturing can also introduce various impurities. In contrast, one or more embodiments further include utilizing reagents and raw materials in the battery manufacturing process 100 that are free of impurities or have only trace amounts of impurities.

[0039] The methods described herein can further process the produced Na2SO4 solution 106 to produce NaOH and H2SO4. By minimizing the concentrations in the Na2SO4 solution 106, the system can eliminate certain downstream technologies that would normally be required to produce NaOH and H2SO4 from the Na2SO4 solution 106.

[0040] As mentioned above, in some embodiments, the system can further process the NaSO solution in its solution form (e.g., NaSO solution 106 or NaSO solution 204) produced from the battery manufacturing process 202. For example, FIG. 2 shows a flowsheet of a method 200 for converting NaSO to sodium hydroxide (NaOH) 218 ​​and sulfuric acid (HSO) 220 via an electrochemical salt decomposition process 212. The method 200 can include various intermediate methods for treating the NaSO solution 204 before subjecting it to the electrochemical salt decomposition process 212, as shown in FIG. 2. For example, in various embodiments, the method 200 can include intermediate processing steps, such as processing the NaSO solution 204 through a crystallizer and / or purifying impurities 208 from the NaSO solution 204 by ion exchange purification.

[0041] For example, in one embodiment, method 200 can process NaSO solution 204 through a crystallizer to produce anhydrous NaSO as a crystalline solid or in powder form. Additionally, in some embodiments, NaSO solution 204 may contain impurities 208, which method 200 can further process through ion exchange, as described in more detail below. Indeed, NaSO solution 204 may contain trace amounts of various metals of significant value (e.g., nickel (Ni), cobalt (Co), manganese (Mn), aluminum (Al)). Method 200 can process these metals, for example, through crystallization or precipitation reactions, so that the method can separate, recover, and / or recycle trace amounts of these metals from NaSO solution 204 and feed them back into battery recycling process 222. Indeed, by being located within a single, integrated plant, these processes can be directly interconnected to provide process intensification.

[0042] In one or more embodiments, the by-product Na2SO4 solution 204 that the method 200 produces from ammonia recovery in the battery manufacturing process 202 contains water-soluble ionic forms, such as Ni 2+, Co 2+ , Mn 2+ , Al 3+ Impurities 208 that may be produced by the method 200 include chloride and fluoride ions, as well as water-soluble ionic forms (e.g., Cl - and F - ) In some embodiments, the method 200 can process the NaSO stream through the crystallizer after ammonia recovery to produce anhydrous NaSO solids 206. Generally, the crystallization step acts as a purification step to reduce impurities. In one or more embodiments, a liquid purge stream containing NaSO and impurities is separated, while the primary stream of NaSO solids proceeds to salt cracking or is sent for sale.

[0043] As mentioned above, in some embodiments, the method 200 can further purify impurities 208 from the NaSO solution 204 before subjecting the NaSO solution 204 to the electrochemical salt decomposition process 212 to produce NaOH 218 and HSO 220. Because electrochemical devices are sensitive to metal impurities, residual metals in the solution stream can contaminate membranes and electrodes, which can increase cell resistance and reduce performance. This requires many salt decomposition systems to purify their raw materials, necessitating additional purification steps to remove residual metals, as discussed above. In some embodiments, the method 200 can ensure that the NaSO solution 204 is sufficiently pure for use in the electrochemical salt decomposition process 212 without one or more of the traditionally required purification steps. For example, in one or more embodiments, a pCAM process serves as the Ca, Mg removal process. In such embodiments, the method includes a purification step IX and eliminates the precipitation step.

[0044] For example, in one or more embodiments, the method 200 may utilize a single purification step, such as ion exchange purification, to remove impurities 208 from the NaSO solution 204. In many conventional systems, various impurities 208 (e.g., Ca) are removed from any stream that is subjected to electrochemical salt splitting. 2+ and Mg 2+ ), multiple methods are required to remove Ca. For example, conventional systems require multiple methods that include both an initial hardness removal step and an ion exchange purification step. In fact, many conventional systems 2+ and Mg 2+ These conventional systems then require initial hardness removal to reduce impurities such as ammonium hydroxide to concentrations below 20 parts per million (ppm). These systems then reduce impurities to concentrations in the parts per billion (ppb) range (e.g., less than 50 ppb for total impurities, Ca 2+ and Mg 2+ An ion exchange purification step is required to remove impurities (less than 20 ppb for NaSO). However, the disclosed systems and methods improve over conventional systems, for example, by eliminating the initial hardness removal step. In these or other embodiments, the method 200 may utilize a single ion exchange purification step for the electrochemical salt decomposition process 212 to remove multivalent ion impurities to acceptable levels (e.g., less than 20-50 ppb). The method 200 may remove impurities 208 in a single purification step, at least in part, due to the low impurity concentration of the produced NaSO solution 204, as described above with respect to FIG. 1. Indeed, in one or more embodiments, the single purification step may reduce the impurity concentration to less than 200 ppb, less than 100 ppb, less than 50 ppb, less than 20 ppb, less than 15 ppb, less than 10 ppb, or less than 5 ppb. In other embodiments, the characteristics of the battery manufacturing or recycling process may allow the electrochemical salt decomposition process to operate under less stringent impurity limits and may be able to tolerate impurities down to 5 ppm.

[0045] In some embodiments, the method of one or more embodiments can purify the NaSO outlet stream (e.g., NaSO 204) with an in-line ion exchange column similar to the ion exchange methods described in Spanish Patent Application ES2056752A6, published October 1, 1994, and U.S. Patent No. 4,707,347, issued November 17, 1987, both of which are incorporated herein by reference in their entireties. In other embodiments, the method of one or more embodiments can utilize a cation exchange resin to absorb Ni, Co, Mn, Al, and any other residual ionic metal impurities from the solution before feeding the solution to the electrochemical salt decomposition device. As noted above, in one or more embodiments, the method of one or more embodiments can recycle impurities 208 (e.g., metal impurities) back into the battery recycling process 222 as recycled metal feedstock.

[0046] In one or more embodiments, the method of one or more embodiments can further process the purified NaSO solution 210 by converting the produced NaSO to NaOH 218 and HSO 220 via an electrochemical salt decomposition process 212. In some embodiments, the electrochemical salt decomposition process 212 can include electrolysis 214 or bipolar membrane electrodialysis 216. In one or more embodiments, the electrochemical device can include two or more compartments separated by an ion exchange membrane. Additionally, the electrochemical salt decomposition process 212 can utilize membrane electrode designs including stainless steel electrodes, nickel-plated steel electrodes, nickel electrodes, and / or mixed metal oxide electrodes, in any combination. Alternatively, the electrochemical salt decomposition process 212 can utilize an electrode design that alters the electrode half-reaction from oxygen production and / or hydrogen production. For example, one or more embodiments utilize gas diffusion electrodes. Details of decomposing the Na2SO4 of the purified Na2SO4 solution 210 into NaOH 218 and H2SO4 220 using an electrochemical salt decomposition process 212 are further described with reference to Figures 5-10.

[0047] Additionally, the method of one or more embodiments may recycle the produced NaOH 218 and / or HSO 220 back into the battery manufacturing process 202 to form a closed system. For example, whether utilizing electrolysis 214 or bipolar membrane electrodialysis 216 for the electrochemical salt decomposition process 212, the method of one or more embodiments may separate the NaSO of the purified NaSO solution 210 to produce NaOH 218 and HSO 220, as shown in FIG. 2. Additionally, the method of one or more embodiments may recycle the produced NaOH 218 and HSO 220 back into the battery manufacturing process 202. Thus, the method of one or more embodiments may incorporate the NaSO produced from the battery manufacturing process 202 into a method for converting NaSO to NaOH 218 and HSO 220, and incorporate the NaOH 218 and HSO 220 produced from the decomposition of NaSO into the battery manufacturing process 202 to operate as a closed system. By creating a single closed system within the loop, the method of one or more embodiments can achieve efficiencies that result in capital and cost savings. For example, by creating a closed system, the method can avoid the need for significant amounts of equipment otherwise required to concentrate H2SO4 to high concentrations. Beyond eliminating impurity removal or concentration steps in the electrochemical salt decomposition process by controlling impurities, other methods and embodiments can achieve efficiencies by adapting the battery manufacturing process to enable process intensification of the electrochemical process. One such embodiment would be to modify the battery manufacturing process to handle impure acids or bases, thereby enabling the selection of a two-compartment electrochemical cell that is more efficient but produces impure acids or bases. For example, modifications to the battery manufacturing process could include changing the recipe and operating conditions (concentration, pH, temperature, residence time) of the pCAM reactor process or changing the conditions of the pCAM filtration process (e.g., rinse solution volume, rinse solution composition, etc.).

[0048] Reference is now made to Figure 3, which illustrates a process diagram of a method 300 for producing lithium sulfate (LiSO) from a battery recycling process, according to one or more embodiments. For example, in one embodiment, the method 300 can extract LiSO, along with other valuable metals (e.g., Ni, Co, Mn, Al), from treated recycled battery material 302 in a reductive leaching process using HSO and hydrogen peroxide (HO). Some reactions are described by simplified chemical equations (2), (3), and (4) shown below. MO (S) + H2SO4 (aq) → MSO 4 (aq) + H2O (l) (2) LiO (S) + H2SO4 (aq) → Li2SO4 (aq) + H2O (l) (3) Al2O3 (S) + 3H2SO4 (aq) → Al2(SO4)3 (aq) + 3H2O (l) (4)

[0049] With respect to formula (2), the metal oxide (MO) solids include metals (M), such as Ni, Co, and Mn, to name a few. Similarly, the resulting aqueous solutions of metal sulfates (MSO4) include, among others, the corresponding metals, e.g., NiSO4, CoSO4, and MnSO4.

[0050] After the leaching process, the method 300 can separate the mixture of dissolved MSO, LiSO, and Al(SO) in the leachate 304 into their components, such as Al precipitate 310, metal precipitate 312, and LiSO (e.g., from the LiSO solution 308), using separation techniques including crystallization, precipitation, solid-liquid separation, and particle size separation, among others. The metal precipitate 312 can include solids of MSO, Al(OH), and M(OH), where the metals (M) include, but are not limited to, Ni, Co, and Mn, to name a few. The method 300 can further crystallize solid LiSO as lithium sulfate monohydrate (LiSO·HO) 314 from the LiSO solution 308 produced from the separation technique. In one embodiment, the method 300 can produce a final Li2SO4·H2O 314, which can be relatively pure and may have a composition as set forth in Table 2 below. TIFF2025533551000003.tif10572Table 2. Approximate composition of lithium sulfate monohydrate (LSM).

[0051] As shown in Table 2, the mass percentage of lithium can be approximately 10.43, with a theoretical limit of approximately 10.85, implying an overall purity of approximately 96% for the Li2SO4 outlet stream from lithium battery recycling. Residual sodium is an impurity resulting from using municipal water, which method 300 can remove or minimize by treating the water by reverse osmosis or by deionization. Calcium (Ca) and magnesium (Mg) are present as a result of the reagents method 300 utilizes in the recycling process. Method 300 can remove Al, iron (Fe), Co, and copper (Cu) prior to chemical treatment, and some Ni may remain in the Li2SO4·H2O 314 composition.

[0052] The remaining chemical elements, such as sulfate (SO), may have a mass percentage ranging from about 75% to about 76%, with the theoretical limit being about 75%, with most present as sulfate, with a small remainder from impurities. Water (HO) may have a mass percentage ranging from about 14.1% to about 14.5%, with most of the water bound in the monohydrate, leaving very little free water.

[0053] In some embodiments, the method 300 can produce a Li2SO4 product, such as Li2SO4·H2O 314 or a Li2SO4 solution, with low impurity concentrations. Indeed, the method 300 can produce a Li2SO4 solution in which the concentration of at least some of the impurities in the solution is less than 20 parts per million (ppm). The produced Li2SO4 solution contains nickel ions (Ni 2+ ), cobalt ions (Co 2+ ), copper ions (Cu 2+ ), aluminum ions (Al 3+ ), iron ions (Fe 2+ ), calcium ions (Ca 2+ ), magnesium ions (Mg 2+ ), chloride ions (Cl - ), and / or fluoride ions (F - In some embodiments, the method 300 can include various methods for minimizing the concentration of these impurities in the LiSO solution produced from the battery recycling process.

[0054] For example, a method for minimizing the concentration of impurities in the produced LiSO solution can include managing the inputs of a battery recycling process. For example, conventional battery manufacturing systems typically utilize municipally supplied water with minimal or no water filtration, potentially introducing various of the aforementioned impurities into product streams, such as the LiSO solution. For example, as noted above, the use of municipal water can potentially introduce sodium into the system. However, method 300 can minimize sodium in the LiSO solution by utilizing reverse osmosis water and / or deionized water as the water used in the leaching process, e.g., using HSO and H0. Method 300 can further minimize other impurities by ensuring that reagents, such as precipitation reagent 306 and raw materials, have no impurities or only trace amounts of impurities. For example ... 2+ or Mg 2+ Additionally, the method 300 can utilize F-free reagents and raw materials. - By utilizing reagents that do not introduce F and utilizing electrolyte-free battery feedstocks (e.g., battery scrap) as the processed recycled battery material 302, - Contamination can be minimized. Additionally, in some embodiments, rather than using NaOH as a pH control agent, the method 300 can utilize the generated LiOH to control the pH.

[0055] In some embodiments, by minimizing the concentration of impurities in the LiSO solution, the method 300 can minimize downstream purification techniques. For example, the method 300 can further process the produced LiSO solution to produce LiOH and HSO. By minimizing the concentrations in the LiSO solution, the method 300 can eliminate certain downstream techniques that would normally be required to produce LiOH and HSO from the LiSO solution, as described in more detail below.

[0056] As mentioned above, in some embodiments, the method 300 can further process LiSO in its solution form (e.g., LiSO solution 404) produced from the battery recycling process 402. For example, FIG. 4 shows a process diagram of a method 400 for converting LiSO to LiOH 418 and HSO 420 via an electrochemical salt decomposition process 412, according to one or more embodiments. The method 400 can have various intermediate methods for treating the LiSO solution 404 before subjecting it to the electrochemical salt decomposition process 412, as shown in FIG. 4. For example, in various embodiments, the method 400 can include intermediate treatment methods, such as processing the LiSO solution 404 through a crystallizer and / or purifying impurities 408 from the LiSO solution 404 by ion exchange purification.

[0057] For example, in one or more embodiments, method 400 can further process Li2SO4 solution 404 through a crystallizer to produce anhydrous lithium sulfate solids. Additionally, in some embodiments, Li2SO4 solution 404 can include impurities 408, which method 400 can further process through ion exchange, as described in more detail below. Indeed, Li2SO4 solution 404 contains metal impurities in water-soluble ionic form, such as Ni 2+ , Co 2+ , Al 3+ , and / or chlorine and fluoride ions (e.g., Cl - and F -), and other impurities such as fluorine and chlorine. In some embodiments, the method 400 can subject the LiSO solution 404 to a crystallizer treatment to produce anhydrous lithium sulfate (LiSO) solids 406. The method 400 can similarly produce metals, including chlorine and fluorine impurities, in the LiSO solids 406 in their solid ionic form and as part of the LiSO solid crystal structure. In some embodiments, the method 400 can extract and recycle the solid ionic forms back into the battery recycling process 402. Indeed, by being located within a single, combined plant, these processes can be directly interconnected to provide process intensification.

[0058] It will be understood by those skilled in the art that while the Li2SO4·H2O may have the composition shown above, the Li2SO4·H2O may have other compositions or concentrations depending on the processing steps.

[0059] Additionally, in some embodiments, method 400 may utilize a single-stage crystallization to crystallize LiOH. Indeed, in these or other embodiments, method 400 may eliminate the need for multi-stage crystallization by minimizing the sodium content in the feedstock (e.g., LiSO solution 404). For example, rather than using NaOH, method 400 may limit sodium content by utilizing LiOH 418 produced from electrochemical salt decomposition process 412, as described in further detail below, as a pH control. Furthermore, in some examples, method 400 may use LiOH to replace lime to form the metal precipitate. In a further example, LiOH may be combined with CO to form a LiCO solution that can be used in place of NaCO as part of the impurity removal step. Additionally, as described above with respect to FIG. 3 for a method for producing LiSO from a battery recycling process, method 400 may minimize sodium by utilizing reverse osmosis and / or deionized water in an intermediate purification method prior to electrochemical salt decomposition process 412. Additionally, method 400 can utilize reagents that do not introduce sodium, specifically by substituting NaCO for CO in processes including polyvalent cation removal steps prior to salt decomposition, using lime instead of caustic soda in precipitation steps during any pre-salt decomposition purification steps, and using electrochemical rather than chemical processes whenever possible. Additionally, method 400 can utilize sodium-free battery feedstocks (e.g., battery scrap in battery recycling process 402). Additionally, in one or more embodiments, method 400 can include a bleed to manage impurity buildup, as described in more detail below.

[0060] As mentioned above, in some embodiments, the method 400 can further purify impurities 408 from the LiSO solution 404 before subjecting the LiSO solution 404 to the electrochemical salt decomposition process 412 to produce LiOH 418 and HSO 420. As discussed above, electrochemical devices are sensitive to metal impurities, and residual metals in the solution stream can contaminate membranes and electrodes, which can increase cell resistance and reduce performance. This causes many salt decomposition systems to require pure raw materials that require additional purification steps to remove residual metals. Therefore, in some embodiments, the method of one or more embodiments can ensure that the LiSO solution 404 is sufficiently pure for use in the electrochemical salt decomposition process 412 without extensive purification steps. For example, the method of one or more embodiments can purify the LiSO solution 404 using an in-line ion exchange column or cation exchange resin, as described for the purification of the NaSO solution and FIG. 2.

[0061] Additionally, the method of one or more embodiments may utilize a single purification step, e.g., ion exchange purification, to remove impurities 408 from the LiSO solution 404, similar to the ion exchange purification method described above with respect to the NaSO solution and Figure 2. Indeed, the method of one or more embodiments may utilize a similar method with the LiSO solution 404, at least in part due to the minimal concentration of impurities 408 in the LiSO produced from the battery recycling process as described above with respect to Figure 3.

[0062] As discussed above, in some embodiments, the method of one or more embodiments may convert the Li2SO4 produced from the battery recycling process 402 in the purified Li2SO4 solution 410 to LiOH 418 and H2SO4 420 via an electrochemical salt decomposition process 412. Additionally, the method of one or more embodiments may utilize methods and devices equivalent to those described above with respect to Figure 2 for converting Na2SO4 to NaOH and H2SO4 to convert the Li2SO4 in the purified Li2SO4 solution 410 to LiOH 418 and H2SO4 420. Indeed, further details regarding some methods and devices are described with respect to Figures 5-10.

[0063] Further, in one or more embodiments, method 400 can include producing LiSO from the battery recycling process by recycling at least HSO 420 to the battery recycling process, and converting the produced LiSO to LiOH 418 and HSO 420 in a closed system. For example, as shown in FIG. 4, whether utilizing electrolysis 414 or bipolar membrane electrodialysis 416 for electrochemical salt decomposition process 412, method 400 can separate the LiSO of purified LiSO solution 410 to produce LiOH 418 (e.g., in LiOH solution) and HSO 420 (e.g., in solution). Indeed, method 400 can operate as a closed system by incorporating the LiSO produced from battery recycling process 402 into a process that converts LiSO to LiOH 418 and HSO 420, and recycling the HSO 420 back to the process that produces LiSO. For example, H2SO4 420 can be recycled back to the process of leaching the treated recycled battery material 302. Additionally, method 400 can recycle the produced LiOH 418 (e.g., as a LiOH solution) back to the battery recycling process 402 or the battery manufacturing process 422. Indeed, the LiOH solution containing LiOH 418 can be sent to a crystallizer to produce LiOH·HO solids, which can be sold or sent to the battery manufacturing process 422. Besides eliminating the impurity removal or concentration step in the electrochemical salt decomposition process by controlling impurities, other methods and embodiments can achieve efficiency by adapting the battery recycling process to enable process intensification of the electrochemical process. One such embodiment would be to modify the battery recycling process to handle impure acids or bases, thereby enabling the selection of a more efficient, but impure, two-compartment electrochemical cell.Additionally, modifications to the battery recycling process can include one or more of: (1) changing the location where the acid is recycled back into the battery recycling process; (2) reducing the addition of water and purchased acid (or base) to accommodate impure acid (or base); or (3) controlling conditions in both salt decomposition and battery recycling to avoid unwanted LiSO saturation in any part of the system, which would lead to LiSO crystallization and result in product loss and operational problems.

[0064] Additionally, in some embodiments, the method 400 for producing LiSO from a battery recycling process and converting the produced LiSO to LiOH 418 and HSO 420 in a closed system can include removing the buildup of impurities through a bleed. For example, in a closed or closed-loop system, trace impurity concentrations can build up over time, causing inefficiencies and degradation of system tools and equipment, as well as degradation of product quality. In one or more embodiments, the method 400 produces lithium carbonate (LiCO) from the bleed stream to convert the produced LiSO to LiOH 418 and HSO 420. + In these or other embodiments, the method 400 may further include recovering valuable materials in the bleed stream, such as maximizing the recovery of Na through the addition of NaCO. + The CO2 and LiOH in the bleed stream can be utilized to avoid the addition of CO2. Additionally, the bleed stream can be processed in a zero liquid discharge evaporator for water recovery.

[0065] Reference is now made to Figure 5, which illustrates a method 500 for converting, for example, a NaSO outlet stream produced in Figure 1 or a purified NaSO solution of Figure 2, to NaOH and HSO via an electrolytic salt decomposition process using a two-compartment electrolytic cell 502 and a three-compartment electrolytic cell 504. Similarly, Figure 6 illustrates a process 600 for converting, for example, a LiSO outlet stream produced in Figure 2 or a purified LiSO solution of Figure 4, to LiOH and HSO via an electrolytic salt decomposition process using a two-compartment electrolytic cell 602 and a three-compartment electrolytic cell 604.

[0066] Generally, the two transformations shown in Figures 5 and 6 are substantially similar, the difference being that the initial chemical solutions are NaSO and LiSO, respectively, and the resulting products are NaOH and LiOH, respectively. Both transformations can produce HSO.

[0067] 5 and 6, in a three-compartment electrolysis cell 504, the method of one or more embodiments can include both anion and cation exchange membranes. Depending on the properties, these membranes can be semipermeable to allow transport of specific ions (e.g., anions or cations) across the membrane. In a two-compartment electrolysis cell 502, the method of one or more embodiments can utilize either cation or anion exchange membranes.

[0068] In a three-compartment electrolysis cell 504, the method of one or more embodiments can include supplying a Na2SO4 solution 506 to the central compartment between the anion and cation exchange membranes (right side of FIG. 5). Under an applied potential, sodium ions (Na + ) can migrate through the cation exchange membrane (CEM) to the cathode compartment, while sulfate ions (SO4 2- ) can migrate through the anion exchange membrane (AEM) to the anode compartment. Through the anodic and cathodic reactions, the method of one or more embodiments converts H through the oxidation and reduction of water, respectively. + and OH -The reaction can be written as equations (5) and (6). Anode: 2H2O → O2+ 4H + + 4e - (5) Cathode: 4H2O + 4e - → 2H2+ 4OH - (6)

[0069] In the anode compartment, H + is SO4 2- and combine to form H2SO4, while in the cathode compartment OH - Na + In some embodiments, the method of one or more embodiments further comprises the step of: + and OH at the cathode. - Other electrochemical reactions besides the oxidation and reduction of water can be utilized to produce . For example, one or more embodiments include utilizing variations of an oxygen-depolarized cathode and a hydrogen-depolarized anode.

[0070] In a two-compartment electrolysis cell 502 with a CEM, the method of one or more embodiments can include providing a Na2SO4 solution 506 to the anode compartment. Similarly, under an applied potential, Na + can migrate through the CEM to the cathode compartment, where Na + is the generated OH - In the anode compartment, SO4 2- is the generated H + It combines with hydrogen to produce H2SO4.

[0071] In a two-compartment electrolysis cell 502 with an AEM, the method of one or more embodiments can include providing a NaSO solution 506 to the cathode compartment. Similarly, at an applied potential, the NaSO solution 2- can travel through the AEM to the anode compartment, where SO4 2- is the generated H + In the cathode compartment, Na + is the generated OH- It combines with HCl to produce NaOH.

[0072] As described above, in some embodiments, the method can convert the NaSO solution 506 generated from the outlet stream of the battery manufacturing process to NaOH and HSO via an electrochemical salt decomposition process using either two-compartment or three-compartment electrolysis cells 502-504 as described above. Furthermore, as described above, the method of one or more embodiments can return the resulting NaOH to the precursor cathode active material (pCAM) manufacturing process (see equation (1)) and HSO to the battery recycling process (see equations (2), (3), and (4)) so that the electrochemical salt decomposition enables closed-loop processing in battery recycling and manufacturing. In other words, the system generates NaSO and converts it to NaOH and HSO in a closed-loop battery recycling and manufacturing system. Thus, the NaSO outlet stream generated from the battery manufacturing process is fed to a process that converts NaSO to NaOH and HSO, and the NaOH and HSO from the conversion process are fed to the battery manufacturing process.

[0073] In the LiSO salt decomposition process of Figure 6, the method of one or more embodiments can utilize a similar process as described above for the NaSO salt decomposition process with LiSO replaced by NaSO as described above for both the two-compartment and three-compartment electrolysis cells, and therefore will not be further detailed herein. However, in this example, the system produces LiOH on the cathode side instead of NaOH, while still producing HSO on the anode side.

[0074] In some embodiments, the method of one or more embodiments can convert the LiSO solution 606 produced from the outlet stream of the battery recycling process to LiOH and HSO via an electrochemical salt decomposition process using a two-compartment electrolytic cell 602, a three-compartment electrolytic cell 604, or an electrochemical cell with more than three compartments as described above. In yet another embodiment, the method of one or more embodiments can further treat and calcinate the resulting LiOH with M(OH) to produce lithium-rich cathode active material (CAM), while reusing the HSO in the battery recycling process (see equations (2), (3), and (4)), thus enabling electrochemical salt decomposition to enable closed-loop processing in battery recycling and manufacturing. In other words, the method of one or more embodiments produces LiSO and converts it to LiOH and HSO in a closed-loop battery recycling and manufacturing system, such that the LiSO outlet stream produced from the battery recycling process is fed to a process that converts LiSO to LiOH and HSO, and the LiOH and HSO from the conversion process are fed to the battery recycling process and / or the battery manufacturing process.

[0075] Furthermore, in some embodiments, the methods of one or more embodiments may utilize bipolar membrane electrodialysis as the salt decomposition process described above. For example, FIG. 7 illustrates a method 700a for converting LiSO to LiOH and HSO via a salt decomposition process using bipolar membrane electrodialysis, according to one or more embodiments. Indeed, FIG. 7 illustrates the conversion of LiSO from, for example, the LiSO outlet stream produced in FIG. 4 or the purified LiSO solution of FIG. 4 to LiOH and HSO via a salt decomposition process using bipolar membrane electrodialysis.

[0076] As shown in FIG. 7 , in one or more embodiments, the method of one or more embodiments can utilize an electrodialysis cell including an anode and a cathode separated by multiple membranes that define multiple compartments. For example, FIG. 7 illustrates a bipolar membrane electrodialysis system including an anode followed by a series of membranes, e.g., a CEM, an AEM, a bipolar exchange membrane (BPM), a second CEM, a second AEM, a second BPM, and a third CEM, followed by a cathode. Furthermore, as shown in FIG. 7 , the bipolar membrane electrodialysis system includes compartments between each membrane, between the anode and the first CEM, and between the cathode and the third CEM. Depending on their properties, the CEMs and AEMs can be semipermeable to allow transport of certain ions (e.g., anions or cations) across the membranes. As shown, the bipolar membrane electrodialysis systems of FIGS. 7 and 8 include two cells, each with three compartments. In another embodiment, the bipolar membrane electrodialysis system includes two, three, or more compartments per cell. In further embodiments, the bipolar membrane electrodialysis system can include any non-zero number of cells.

[0077] In some embodiments, a method utilizing the electrodialysis cell described above can include supplying an electrolyte, a LiSO solution 702, a dilute acid, and a dilute base to compartments of the cell to produce a strong base (e.g., LiOH) and a strong acid (e.g., HSO). For example, the method can include supplying an electrolyte in a compartment between an end electrode and the CEM. Further, the method can include supplying a LiSO solution 702 to a compartment between the CEM and the AEM, supplying a dilute acid to a compartment between the AEM and the BPM, and supplying a dilute base to a compartment between the BPM and the CEM. Under an applied potential and / or current, Li + can move from the Li2SO4 solution compartment through the CEM to the adjacent base compartment, and SO4 2- can migrate from the Li2SO4 solution compartment through the AEM to the adjacent acid compartment. Through the BPM reaction driven by an applied potential and / or current, the system converts H from water via ion transfer. + and OH -Each BPM can contain a cation exchange layer (CEL) and an anion exchange layer (AEL). This reaction is explained by equation (7). HO → H + + OH - (7)

[0078] AEL is OH - Li while allowing + CEL prevents the generated H from moving across each BPM. + allows SO4 to enter the acid compartment 2- prevents OH from migrating through each BPM. - Li + to form LiOH, and in the acid compartment H + is SO4 2- Furthermore, while not shown in the diagram, all CEMs have Li ions moving across them. + and all AEMs have SO4 moving across them. 2- It will be understood from the disclosure herein that the method may have the following configurations: In some embodiments, the method may include using other arrangements of membranes in the electrodialysis cell to achieve electrochemical salt splitting, as would be understood by one of ordinary skill in the art.

[0079] 8 illustrates a method 802 for converting Na2SO4 to NaOH and H2SO4 via a salt decomposition process using bipolar membrane electrodialysis, according to one or more embodiments. Indeed, FIG. 8 illustrates the conversion of Na2SO4 from, for example, the Na2SO4 outlet stream produced in FIG. 2 or the purified Na2SO4 solution of FIG. 2 to NaOH and H2SO4 via a salt decomposition process using bipolar membrane electrodialysis.

[0080] As shown in FIG. 8 , in one or more embodiments, the method of one or more embodiments can utilize an electrodialysis cell including an anode and a cathode separated by multiple membranes that define multiple compartments. For example, FIG. 8 illustrates a bipolar membrane electrodialysis system including an anode followed by a series of membranes, e.g., a CEM, an AEM, a bipolar exchange membrane (BPM), a second CEM, a second AEM, a second BPM, and a third CEM, followed by a cathode. Furthermore, as shown in FIG. 8 , the bipolar membrane electrodialysis system includes compartments between each membrane, between the anode and the first CEM, and between the cathode and the third CEM. Depending on their properties, the CEMs and AEMs can be semipermeable to allow transport of certain ions (e.g., anions or cations) across the membranes.

[0081] In some embodiments, a method utilizing the electrodialysis cell described above can include supplying an electrolyte, a Na2SO4 solution 702b, a dilute acid, and a dilute base to compartments of the cell to produce a strong base (e.g., NaOH) and a strong acid (e.g., H2SO4). For example, the method can include supplying an electrolyte to a compartment between the anode and the first CEM and a compartment between the cathode and the third CEM. Further, the method can include supplying a Na2SO4 solution 702b to a compartment between the CEM and the AEM, supplying a dilute acid to a compartment between the AEM and the BPM, and supplying a dilute base to a compartment between the BPM and the CEM. Under an applied potential, Na + can travel through the second CEM to the section between the first BPM and the second CEM, and SO4 2- can travel through the second AEM to the compartment between the second AEM and the second BPM. Through the BPM reaction, the system converts H through the oxidation and reduction of water. + and OH - Each BPM can include a cation exchange layer (CEL) and an anion exchange layer (AEL).

[0082] The AEL of the first BPM is Na + prevents the first BPM from moving through, and the second BPM's CEL is SO42- OH is prevented from migrating through the second BPM. In the area between the first BPM and the second CEM, - Na + and combine with NaOH to generate NaOH, and in the compartment between the second AEM and the second BPM, H + is SO4 2- In some embodiments, the method further comprises combining H with BPM to produce HSO. + and OH - Other electrochemical reactions besides the oxidation and reduction of water can be utilized to produce Na. Furthermore, while not shown in the diagram, all CEMs have Na transport across them. + and all AEMs have SO4 moving across them. 2- It is understood that the .lambda.

[0083] In some embodiments, the method can include achieving electrochemical salt splitting using other arrangements of membranes within the electrodialysis cell, as would be understood by one of ordinary skill in the art. For example, Figures 9 and 10 show the conversion of LiSO to LiOH and HSO via a salt splitting process using a bipolar membrane electrodialysis cell with two compartments, according to one or more embodiments. Two-compartment bipolar electrodialysis functions similarly to three-compartment electrodialysis, except that the central salt compartment is combined with either an acid or base compartment.

[0084] For example, in a two-compartment bipolar electrodialysis cell system 900 with a CEM, the method of one or more embodiments can include providing a Li2SO4 solution 902 to the acid compartment. Under an applied potential, Li + moves through the CEM to the base compartment, and Li + is the generated OH - In the acid compartment, SO4 2- is the generated H + to produce H2SO4. A mixture of Li2SO4 solution and H2SO4 exits the acid compartment. A pure stream of LiOH solution exits the base compartment.

[0085] In a two-compartment bipolar electrodialysis cell 1000 with an AEM, the method of one or more embodiments can include feeding a LiSO solution 1002 to the base compartment. Similarly, under an applied potential, SO 2- moves through the AEM to the acid compartment, and the generated H + and SO4 2- In the base compartment where Li can bind to form H2SO4, + is the generated OH - The Li2SO4 solution and LiOH combine to form LiOH. A mixture of Li2SO4 solution and LiOH exits the base compartment. A pure stream of H2SO4 solution exits the acid compartment.

[0086] 9 and 10 illustrate two-compartment bipolar electrodialysis cell systems 900 and 1000 for converting LiSO to LiOH and HSO, it will be apparent to one skilled in the art that similar systems can be utilized for converting NaSO to NaOH and HSO. For example, the method of one or more embodiments can include feeding NaSO solution to systems 900 and 1000 instead of LiSO solution to produce NaOH and HSO via a similar mechanism as described above with respect to FIGS.

[0087] 1-10, corresponding text, and examples provide several different systems and methods for producing NaSO and LiSO from a battery manufacturing process and a battery recycling process, respectively, and combining with HSO to convert the NaSO and LiSO to NaOH and LiOH, respectively. In addition to the above, embodiments may also be described in terms of flowcharts having operations for achieving particular results. For example, FIGS. 11 and 12 show flowcharts of example sequences of operations according to one or more embodiments.

[0088] While Figures 11 and 12 illustrate operations according to some embodiments, alternative embodiments may omit, add, rearrange, and / or modify any of the operations shown in Figures 11 and 12. The operations of Figures 11 and 12 may be performed as part of a method. Alternatively, a system may perform the operations of Figures 11 and 12. Furthermore, operations described herein may be repeated or performed in parallel with each other or with different instances of equivalent or other similar operations.

[0089] 11 shows an example sequence of operations 1100 for producing NaSO from a battery manufacturing process and converting the NaSO to NaOH and HSO. The sequence of operations 1100 can include an operation 1102 for producing sodium sulfate (NaSO) from the battery manufacturing process and an operation 1104 for converting the produced sodium sulfate (NaSO) to sodium hydroxide (NaOH) and sulfuric acid (HSO).

[0090] For example, in one or more embodiments, the series of operations 1100 can include producing sodium sulfate (NaSO) from a battery manufacturing process and converting the produced sodium sulfate (NaSO) to sodium hydroxide (NaOH) and sulfuric acid (HSO) via an electrochemical salt decomposition process.

[0091] In one or more embodiments, the electrochemical salt decomposition process includes one of electrolysis or bipolar membrane electrodialysis.

[0092] Additionally, in some embodiments, the electrochemical salt decomposition process utilizes a membrane electrode design having at least one of a stainless steel electrode, a nickel-plated steel electrode, a nickel electrode, or a mixed metal oxide electrode.

[0093] Additionally, in some embodiments, the electrochemical salt decomposition process utilizes a membrane electrode design that changes the electrode half-reaction from oxygen production and / or hydrogen production. More specifically, in one or more embodiments, the electrode design includes a gas diffusion electrode.

[0094] Further, in some embodiments, producing sodium sulfate (NaSO) from the battery manufacturing process includes producing a sodium sulfate solution, wherein the sodium sulfate solution has a concentration of impurities less than 20 parts per million (ppm).

[0095] In some embodiments, the impurity is nickel ions (Ni 2+ ), cobalt ions (Co 2+ ), manganese ions (Mn 2+ ), aluminum ions (Al 3+ ), potassium ions (K + ), calcium ions (Ca 2+ ), magnesium ions (Mg 2+ ), chloride ions (Cl - ), or fluorine ion (F - )

[0096] Further, in some embodiments, converting the produced sodium sulfate (NaSO) to sodium hydroxide (NaOH) and sulfuric acid (HSO) includes removing impurities from the sodium sulfate solution using single ion exchange purification.

[0097] Additionally, in some embodiments, the series of operations 1100 can include recycling at least one of sodium hydroxide (NaOH) or sulfuric acid (H2SO4) into the battery manufacturing process to form a closed system.

[0098] 12 shows an example sequence of operations 1200 for producing LiSO from a battery recycling process and converting the LiSO to LiOH and HSO. The sequence of operations 1200 can include an operation 1202 for producing lithium sulfate (LiSO) from the battery recycling process and an operation 1204 for converting the produced lithium sulfate (LiSO) to lithium hydroxide (LiOH) and sulfuric acid (HSO).

[0099] Additionally, in some embodiments, the series of operations 1200 can include producing lithium sulfate (LiSO) from a battery recycling process and converting the produced lithium sulfate (LiSO) to lithium hydroxide (LiOH) and sulfuric acid (HSO) via an electrochemical salt decomposition process.

[0100] In one or more embodiments, the electrochemical salt decomposition process includes one of electrolysis or bipolar membrane electrodialysis.

[0101] Additionally, in some embodiments, the electrochemical salt decomposition process utilizes an electrochemical electrode design that includes at least one of a stainless steel electrode, a nickel-plated steel electrode, a nickel electrode, or a mixed metal oxide electrode.

[0102] Additionally, in some embodiments, the electrochemical salt decomposition process utilizes a change in electrode half-reaction from oxygen production and / or hydrogen production. More specifically, in one or more embodiments, the electrode design includes a gas diffusion electrode.

[0103] Further, in some embodiments, producing lithium sulfate (LiSO) from the battery recycling process includes leaching the recycled battery material with a leach solution including sulfuric acid (HSO), hydrogen peroxide (H0), and at least one of deionized water or reverse osmosis water.

[0104] In some embodiments, producing lithium sulfate (LiSO) from a battery recycling process includes producing a lithium sulfate solution, wherein a concentration of impurities in the lithium sulfate solution is less than 20 parts per million (ppm).

[0105] Additionally, in some embodiments, the impurities include nickel ions (Ni 2+ ), cobalt ions (Co 2+ ), copper ions (Cu 2+ ), aluminum ions (Al 3+ ), iron ions (Fe 2+ ), calcium ions (Ca 2+ ), magnesium ions (Mg 2+ ), chloride ions (Cl - ), or fluorine ion (F - )

[0106] Additionally, in some embodiments, generating the lithium sulfate solution includes limiting the battery feedstock of the battery recycling process to at least one of electrolyte-free battery scrap or battery cells using a fluorine-free electrolyte.

[0107] Further, in some embodiments, converting the produced lithium sulfate (LiSO) to lithium hydroxide (LiOH) and sulfuric acid (HSO) includes removing impurities from the lithium sulfate solution using single ion exchange purification.

[0108] In one or more embodiments, converting the produced lithium sulfate (LiSO) to lithium hydroxide (LiOH) and sulfuric acid (HSO) comprises crystallizing the lithium hydroxide (LiOH) using single-stage crystallization.

[0109] Further, in some embodiments, producing lithium sulfate (LiSO) from the battery recycling process and converting the produced lithium sulfate (LiSO) to lithium hydroxide (LiOH) and sulfuric acid (HSO) is carried out in a closed system by recycling the sulfuric acid (HSO) to the battery recycling process.

[0110] Additionally, in some embodiments, the series of operations 1200 can include recycling the produced lithium hydroxide (LiOH) back into at least one of a battery recycling process or a battery manufacturing process.

[0111] While exemplary embodiments have been particularly shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the embodiments encompassed by the appended claims. For example, other useful embodiments may be achieved if the steps of the disclosed techniques are performed in a different order, and / or if the components in the disclosed systems are combined in a different way, and / or if other components are substituted or supplemented. Accordingly, other embodiments are within the scope of the present disclosure.

Claims

1. Sodium sulfate (Na ２ SO ４ ) and The produced sodium sulfate (Na ２ SO ４ ) with sodium hydroxide (NaOH) and sulfuric acid (H ２ SO ４ ) via an electrochemical salt decomposition process; A method comprising:

2. 10. The method of claim 1, wherein the electrochemical salt decomposition process comprises one of electrolysis or bipolar membrane electrodialysis.

3. 3. The method of claim 2, wherein the electrochemical salt decomposition process utilizes a membrane electrode design including at least one of a stainless steel electrode, a nickel-plated steel electrode, a nickel electrode, or a mixed metal oxide electrode.

4. 3. The method of claim 2, wherein the electrochemical salt decomposition process utilizes an electrode design that alters the electrode half-reaction from oxygen production or hydrogen production.

5. The sodium sulfate (Na ２ SO ４ 2. The method of claim 1, wherein producing a sodium sulfate solution comprises producing a sodium sulfate solution, wherein the concentration of impurities in the sodium sulfate solution is less than 20 ppm.

6. The impurities include nickel ions (Ni ２＋ ), cobalt ions (Co ２＋ ), manganese ions (Mn ２＋ ), aluminum ions (Al ３＋ ), potassium ions (K ＋ ), calcium ions (Ca ２＋ ), magnesium ions (Mg ２＋ ), chloride ions (Cl - ), or fluorine ions (F － 6. The method of claim 5, comprising one of:

7. The produced sodium sulfate (Na ２ SO ４ ) with the sodium hydroxide (NaOH) and sulfuric acid (H ２ SO ４ 6. The method of claim 5, wherein converting said sodium sulfate solution to sodium sulfate nitrate comprises utilizing single ion exchange purification to remove said impurities from said sodium sulfate solution.

8. The sodium hydroxide (NaOH) or sulfuric acid (H ２ SO ４ 10. The method of claim 1, further comprising recycling at least one of:

9. Lithium sulfate (Li) from the battery recycling process ２ SO ４ ) and The produced lithium sulfate (Li ２ SO ４ ) in a solution of lithium hydroxide (LiOH) and sulfuric acid (H ２ SO ４ ) via an electrochemical salt decomposition process; A method comprising:

10. 10. The method of claim 9, wherein the electrochemical salt decomposition process comprises one of electrolysis or bipolar membrane electrodialysis.

11. 11. The method of claim 10, wherein the electrochemical salt decomposition process utilizes an electrochemical electrode design including at least one of a stainless steel electrode, a nickel plated steel electrode, a nickel electrode, or a mixed metal oxide electrode.

12. 11. The method of claim 10, wherein the electrochemical salt decomposition process utilizes an electrode design that alters the electrode half-reaction from oxygen production or hydrogen production.

13. The lithium sulfate (Li) from the battery recycling process ２ SO ４ ) is produced by sulfuric acid (H ２ SO ４ ), hydrogen peroxide (H ２ O ２ 10. The method of claim 9, comprising leaching the recycled battery material with a leach solution comprising: 1) a leachate comprising: 1) a leachate of 100% ethanol; 2) a leachate of 100% ethanol; and 3) a leachate of 100% ethanol; and 4) a leachate of 100% ethanol; and 5) a leachate of 100% ethanol; and 6) a leachate of 100% ethanol; and 7) a leachate of 100% ethanol; and 8) a leachate of 100% ethanol; and 9) a leachate of 100% ethanol; and ...

14. The lithium sulfate (Li) from the battery recycling process ２ SO ４ 10. The method of claim 9, wherein producing a lithium sulfate solution comprises producing a lithium sulfate solution, wherein the concentration of impurities in the lithium sulfate solution is less than 20 ppm.

15. The impurities include nickel ions (Ni ２＋ ), cobalt ions (Co ２＋ ), copper ions (Cu ２＋ ), aluminum ions (Al ３＋ ), iron ions (Fe ２＋ ), calcium ions (Ca ２＋ ), magnesium ions (Mg ２＋ ), chloride ions (Cl - ), or fluorine ions (F － 15. The method of claim 14, comprising one of:

16. 15. The method of claim 14, wherein generating the lithium sulfate solution includes limiting a battery feedstock for the battery recycling process to at least one of electrolyte-free battery scrap or battery cells using a fluorine-free electrolyte.

17. The produced lithium sulfate (Li ２ SO ４ ) with the lithium hydroxide (LiOH) and sulfuric acid (H ２ SO ４ 15. The method of claim 14, wherein converting the lithium sulfate solution to a sulphuric acid solution comprises using single ion exchange purification to remove the impurities from the lithium sulfate solution.

18. The produced lithium sulfate (Li ２ SO ４ ) with the lithium hydroxide (LiOH) and sulfuric acid (H ２ SO ４ 10. The method of claim 9, wherein converting lithium hydroxide (LiOH) to lithium hydroxide (LiOH) comprises crystallizing the lithium hydroxide (LiOH) using a single-stage crystallization.

19. The lithium sulfate (Li) from the battery recycling process ２ SO ４ ), and the lithium sulfate (Li ２ SO ４ ) with the lithium hydroxide (LiOH) and sulfuric acid (H ２ SO ４ ) is converted into sulfuric acid (H ２ SO ４ 10. The method of claim 9, wherein the method is carried out in a closed system by recycling the recycled fuel into the battery recycling process.

20. 10. The method of claim 9, further comprising recycling the produced lithium hydroxide (LiOH) back into at least one of the battery recycling process or the battery manufacturing process.

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