Electrolytic processes for production of carbonates and alkaline compounds

Abstract

There are provided carbon reduction processes and systems for performing such processes employing an electrolysis cell, including processes and systems for producing lithium carbonate with carbon capture, processes and systems for producing cathode active material with reduced carbon emissions, processes and systems for producing sodium carbonate with carbon capture, and processes and systems for enhancing ocean alkalinity.

Description

ELECTROLYTIC PROCESSES FOR PRODUCTION OF CARBONATES AND ALKALINE COMPOUNDSCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and benefit from United States Patent Application Serial No. 63 / 562,783 filed on March 8, 2024, which is hereby incorporated by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure generally relates to carbon reduction processes and systems employing an electrolysis cell, and in particular as they relate to the preparation or use of materials from the lithium-ion battery industry.BACKGROUND

[0003] The boom in global electric vehicle (EV) sales and the push for a transition to renewable energy has caused a dramatic increase in the demand for Lithium-ion batteries (LIBs), as well as materials used in the production of LIBs.

[0004] Conventional manufacturing processes for producing LIBs and their components emit CO2, and thus have negative impacts on the environment. Indeed, one source of CO2 emission in LIB production comes from cathode production. To synthesize the materials needed for LIB production, such as the cathode active materials (CAMs), significant amounts of heat are needed (e.g. between 800-1000°C) that can only cost-effectively be generated by burning fossil fuels, which emits CO2. Moreover, many LIBs are made using lithium carbonate (U2CO3) as a precursor material for producing the CAMs (e.g. lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium nickel cobalt oxide, etc.). The use of carbon-containing U2CO3, in combination with other precursor cathode active materials (PCAMs), in the manufacture of CAMs results in the further emission of CO2.

[0005] Although our planet has extraordinary capabilities in removing CO2 from the air, including ocean carbon dioxide removal (CDR), the rate of increase in CO2 emissions is overwhelming the natural CDR mechanisms of our planet.

[0006] There is therefore a need for improved carbon reduction processes and systems in the context of LIB production to offset current CO2 emissions, as well as improve ocean CDR.SUMMARY

[0007] The present disclosure provides carbon reduction processes and systems employing an electrolysis cell, and in particular as they relate to the preparation or use of materials from the lithium-ion battery industry and ocean alkalinity enhancement.

[0008] In an embodiment, the present disclosure relates to a process for producing lithium carbonate with carbon capture, comprising: receiving a Li salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising LiOH; and delivering the product comprising LiOH and CO2 to a carbonate production reactor to produce lithium carbonate.

[0009] In an embodiment of the process for producing lithium carbonate, the Li salt-containing solution comprises LiCI, U2SO4, Li3PO4, LiNCh, Lil, or LiBr.

[0010] In an embodiment of the process for producing lithium carbonate, the carbonate production reactor is fluidly coupled to a device or apparatus for providing CO2. In an embodiment, the device or apparatus for providing CO2 is a direct air capture system.

[0011] In an embodiment, the present disclosure relates to a system for lithium carbonate production with carbon capture, the system comprising: an electrolysis cell comprising a cathode and an anode; and a carbonate production reactor configured to receive a product comprising LiOH from the electrolysis cell and CO2 to generate lithium carbonate.

[0012] In an embodiment, the system for lithium carbonate production further comprises a device or apparatus for providing the CO2 to the carbonate production reactor. In an embodiment, the device or apparatus for providing the CO2 is a direct air capture system.

[0013] In an embodiment, the present disclosure relates to a process of producing cathode active material with reduced carbon emissions, comprising: receiving aLi salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising LiOH; delivering the product comprising LiOH and CO2 to a carbonate production reactor to produce lithium carbonate; and mixing the lithium carbonate with precursor cathode active material to produce cathode active material.

[0014] In an embodiment, the present disclosure relates to a process for producing sodium carbonate with carbon capture, comprising: receiving a Na salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising NaOH; and delivering the product comprising NaOH and CO2 to a carbonate production reactor to produce sodium carbonate.

[0015] In an embodiment of the process herein for producing sodium carbonate, the Na salt-containing solution comprises NaCI, Na2SC>4, NagPC^, NaNOg, Nal, or NaBr.

[0016] In an embodiment of the process herein for producing sodium carbonate, the carbonate production reactor is fluidly coupled to a device or apparatus for providing the CO2. In an embodiment, the device or apparatus for providing the CO2 is a direct air capture system.

[0017] In an embodiment, the present disclosure relates to a system for sodium carbonate production with carbon capture, the system comprising: an electrolysis cell comprising a cathode and an anode; and a carbonate production reactor configured to receive a product comprising NaOH from the electrolysis cell and CO2 to generate sodium carbonate.

[0018] In an embodiment, the system herein for sodium carbonate production further comprises a device or apparatus for providing the CO2 to the carbonate production reactor. In an embodiment, the device or apparatus for providing the CO2 is a direct air capture system.

[0019] In an embodiment, the present disclosure relates to a process for enhancing ocean alkalinity, comprising: receiving a salt solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode;producing from the electrolysis cell a product comprising an alkaline compound; and delivering the product comprising an alkaline compound to a body of seawater.

[0020] In an embodiment of the process herein for enhancing ocean alkalinity, the salt solution comprises NaCI. In an embodiment, the NaCI is a by-product from a solar evaporation pond in a lithium brine extraction operation.

[0021] In an embodiment of the process herein for enhancing ocean alkalinity, the salt solution comprises Na2SC>4. In an embodiment, the Na2SC>4 is a by-product from a lithium sulfate to lithium hydroxide or lithium carbonate conversion operation.

[0022] In an embodiment of the process herein for enhancing ocean alkalinity, the alkaline compound comprises NaOH.

[0023] In an embodiment of the process herein for enhancing ocean alkalinity, the product comprising an alkaline compound is flowed directly to or is shipped to a body of seawater.

[0024] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell is a chlor-alkali membrane electrolysis cell, a chlor-alkali diaphragm electrolysis cell, a bipolar membrane electrodialysis cell, or a membrane electrolysis cell.

[0025] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell comprises: an anode compartment; a cathode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a cation exchange membrane interposed between the anode compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions from the anode compartment to an opposed surface of the cation exchange membrane into the cathode compartment; an inlet through which the salt solution is received into an interior of the electrolysis cell; and at least one outlet through which the product is removed from an interior of the electrolysis cell. In an embodiment of performing the processes herein with said electrolysis cell, the salt solution is received into the anode compartment and positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment;water is reduced at the cathode to form OH-; and the positive salt ions and the OH- ions in the cathode compartment together form the alkaline compound.

[0026] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell comprises: an anode compartment; a cathode compartment; a salt depletion compartment interposed between the cathode compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; an anion exchange membrane interposed between the anode compartment and the salt depletion compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the anode compartment; a cation exchange membrane interposed between the salt depletion compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the cathode compartment; an inlet through which the salt solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell. In an embodiment of performing the processes herein with said electrolysis cell, the salt solution is received into the salt depletion compartment; positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; water is reduced at the cathode to form OH-; and the positive salt ions and the OH- ions in the cathode compartment together form the alkaline compound.

[0027] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through onesurface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the salt depletion compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the salt solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell. In an embodiment of performing the processes herein with said electrolysis cell, the salt solution is received into the salt depletion compartment; positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the positive salt ions and the OH- ions in the base-build-up compartment together form the alkaline compound.

[0028] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell comprises: an anode compartment; a cathode compartment; an acid build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the salt depletion compartment is interposed between the cathode compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the salt depletion compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the acid build-up compartment; a secondbipolar exchange membrane interposed between the anode compartment and the acid build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the salt solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell. In an embodiment of performing the processes herein with said electrolysis cell, the salt solution is received into the salt depletion compartment; water is dissociated in the first bipolar membrane and OH- migrates into the salt depletion compartment; and positive salt ions and the OH- ions in the salt depletion compartment together form the alkaline compound.

[0029] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; an anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the acid build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the acid build-up compartment and being configured to dissociate waterwith transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the salt solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell. In an embodiment of performing the processes herein with said electrolysis cell, the salt solution is received into the salt depletion compartment; positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the positive salt ions and the OH- ions in the base-build-up compartment together form the alkaline compound.

[0030] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell comprises: an anode compartment; a cathode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a cation exchange membrane interposed between the anode compartment and the catalyst layer of the gas diffusion electrode, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane; an inlet through which the salt solution is received into the anode compartment; a gas inlet through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell. In an embodiment of performing the processes herein with said electrolysis cell, the salt solution is received into the anode compartment; positive salt ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; the gas comprising O2 is reduced at the cathode to form OH-; and the OH- ions and the positive salt ions in the cathode compartment together form the alkaline compound.

[0031] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment interposed between the cathode compartment and the anode compartment; ananode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; an anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the anion ion exchange membrane into the base build-up compartment; a cation exchange membrane interposed between the anode compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane into the base build-up compartment; an inlet through which the salt solution is received into the anode compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell. In an embodiment of performing the processes herein with said electrolysis cell, the salt solution is received into the anode compartment; positive salt ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the anion exchange membrane to the opposed surface of the anion exchange membrane into the base build-up compartment; and the OH- ions and the positive salt ions in the base build-up compartment together form the alkaline compound.

[0032] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the membrane electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathodecompartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membrane into the base build-up compartment; a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second anion exchange membrane interposed between the salt depletion compartment and the anode compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the anode compartment; an inlet through which the salt solution is received into the salt depletion compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell. In an embodiment of performing the processes herein with said electrolysis cell, the salt solution is received into the salt depletion compartment; positive salt ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base build-up compartment; and the OH- ions and the positive ions in the base build-up compartment together form the alkaline compound.

[0033] In an embodiment of any of the processes and systems disclosed herein, the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anodepositioned to extend within the interior of the membrane electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a first anion exchange membrane, the first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membrane into the base build-up compartment; a first cation exchange membrane interposed between the salt depletion compartment and the base buildup compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the acid build-up compartment; a second cation exchange membrane interposed between the acid build-up compartment and the anode compartment, the second cation exchange membrane being configured to exchange ions received from the anode compartment to an opposed surface of the second cation exchange membrane into the acid build-up compartment; an inlet through which the salt solution is received into the salt depletion compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell. In an embodiment of performing the processes herein with said electrolysis cell, the salt solution is received into the salt depletion compartment; positive salt ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base build-up compartment; and the OH- ions and the positive salt ions in the base build-up compartment together form the alkaline compound.

[0034] Other aspects and embodiments of the disclosure are evident in view of the detailed description provided herein.BRIEF DESCRIPTON OF THE DRAWINGS

[0035] Further advantages, permutations and combinations of the invention will now appear from the above and from the following detailed description of the various particular embodiments of the invention taken together with the accompanying drawings, each of which are intended to be non-limiting, in which:

[0036] FIG. 1 shows process flow diagrams of exemplary processes of the present disclosure for producing lithium carbonate with carbon capture (panel (A)), including optional use of the lithium carbonate as a precursor material for producing cathode active materials (CAMs) (panel (B)).

[0037] FIG. 2 shows process flow diagrams of exemplary processes of the present disclosure for producing sodium carbonate with carbon capture (panel (A)), including optional lithium carbonate production via chemical precipitation of lithium salts with the sodium carbonate (panel (B)).

[0038] FIG. 3 is a process flow diagram of an exemplary process of the present disclosure for enhancing ocean alkalinity.

[0039] FIG. 4 is a schematic diagram of an exemplary chlor-alkali membrane electrolysis cell showing exemplary feed and product streams.

[0040] FIG. 5 is a schematic diagram of an exemplary chlor-alkali diaphragm electrolysis cell showing exemplary feed and product streams.

[0041] FIG. 6 is a schematic diagram of an exemplary 3-compartment electrolysis cell comprising a cation exchange membrane (GEM) and an anion exchange membrane (AEM), showing exemplary feed and product streams.

[0042] FIG. 7 is a schematic diagram of an exemplary multi-compartment cell comprising an optionally repeating unit consisting of a bipolar membrane and a GEM, showing exemplary feed and product streams. A 2-compartment embodiment is shown inFIG. 7, but the cell may comprise additional compartments in view of the optionally repeating unit.

[0043] FIG. 8 is a schematic diagram of an exemplary multi-compartment cell comprising an optionally repeating unit consisting of a bipolar membrane and an AEM, showing exemplary feed and product streams. A 2-compartment embodiment is shown in FIG. 8, but the cell may comprise additional compartments in view of the optionally repeating unit.

[0044] FIG. 9 is a schematic diagram of an exemplary multi-compartment cell comprising an optionally repeating unit consisting of a bipolar membrane, an AEM and a GEM, showing exemplary feed and product streams. A 3-compartment embodiment is shown in FIG. 8, but the cell may comprise additional compartments in view of the optionally repeating unit.

[0045] FIG. 10 is a structural diagram of eight exemplary gas diffusion electrodes of the present disclosure (GDE-1 ) comprising at least a catalyst layer (CL) and a gas diffusion layer (GDL) (panel (a)), and in some exemplary embodiments of the GDE-1 further comprising: a microporous layer (MPL); a mesh; an anion exchange membrane (AEM); or a combination thereof (panels (b), (c), (d), (e), (f), (g) and (h)).

[0046] FIG. 11 is a structural diagram of four exemplary gas diffusion electrodes of the present disclosure (GDE-2) comprising at least a gas diffusion layer and a catalyst coated membrane (CCM) (panel (a)), and in some exemplary embodiments of the GDE-2 further comprising: a microporous layer (MPL); a mesh; or a combination thereof (panels (b), (c) and (d))-

[0047] FIG. 12 is a structural diagram of two 3-D exemplary gas diffusion electrodes of the present disclosure (GDE-3) comprising at least a gas diffusion layer (GDL) and a catalyst layer (CL) with a thickness (T) configured to consume a liquid reactant diffusing towards the GDL (panel (a)), and in another exemplary embodiment further comprising a mesh (panel (b)).

[0048] FIG. 13 is a structural diagram of four exemplary gas diffusion electrodes of the present disclosure (GDE-4) comprising at least a first gas diffusion layer (1stGDL) and a catalyst layer (CL), an ionomer layer (IL) and an anion exchange membrane (AEM), and asecond gas diffusion layer (2ndGDL) there between (panel (a)), and in some exemplary embodiments of the GDE-4 further comprising: a microporous layer (MPL); a mesh; or a combination thereof (panels (b), (c) and (d)).

[0049] FIG. 14 is a schematic diagram of an exemplary 5-compartment membrane electrolysis cell with a gas diffusion electrode (“GDE”) in the cathode compartment, showing feed and product streams.

[0050] FIG. 15 is a schematic diagram of an exemplary 4-compartment membrane electrolysis cell with a GDE in the cathode compartment, showing feed and product streams.

[0051] FIG. 16 is a schematic diagram of an exemplary 3-compartment membrane electrolysis cell with a GDE in the cathode compartment, showing feed and product streams.

[0052] FIG. 17 is a schematic diagram of an exemplary 2-compartment membrane electrolysis cell with a GDE in the cathode compartment, showing feed and product streams.DETAILED DESCRIPTION

[0053] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs. Although any methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the present disclosure, exemplary suitable methods and materials are described herein.

[0054] Lithium-ion batteries (LIBs) are a popular power source for clean technologies, like electric vehicles. LIBs can store a significant amount of energy in a small space, have desirable charging capabilities, and have the ability to remain effective after repeated charge cycles. LIBs are a crucial part of current efforts to replace gas-powered cars that emit CO2 and other greenhouse gases. However, conventional manufacturing processes for producing LIBs and their components also emit CO2, and thus have negative impacts on the environment.

[0055] For example, one source of CO2 emission in LIB production comes from cathode production. To synthesize the materials needed for LIB production, such as the cathode active materials (CAMs), significant amounts of heat are needed (e.g. between 800-1000°C) that can only cost-effectively be generated by burning fossil fuels, which emitsCO2. Moreover, many LIBs are made using lithium carbonate (U2CO3) as a precursor material for producing the CAMs (e.g. lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium nickel cobalt oxide, etc.). The use of carbon-containing U2CO3, in combination with other precursor cathode active materials (PCAMs), in the manufacture of CAMs results in the further emission of CO2. Exactly how much CO2 is emitted can vary a lot depending on the type of LIBs produced, the materials needed to produce those LIBs, how the materials are sourced, and the energy sources that are used in manufacturing. There exists a need to offset these CO2 emissions.

[0056] Advantageously, embodiments of the processes and systems disclosed herein enable the production of “carbon-negative” lithium carbonate. In accordance with the processes herein, the LiOH produced via electrolysis can be mixed with CO2 to produce lithium carbonate in a manner that removes or captures CO2 from a desired source (e.g. the air, exhaust gases, etc.). Thus, lithium carbonate as produced by the processes herein is advantageously “carbon-negative”.

[0057] In embodiments herein, the carbon-negative lithium carbonate may be used as a precursor material in the production of CAMs to offset the CO2 emissions of CAM manufacturing processes. Thus, a CAM manufacturer could purchase the carbon-negative lithium carbonate to obtain a carbon credit against its CO2 emissions. In certain embodiments, the CO2 emissions from the CAM manufacturing processes could even be captured and recycled back to be used in reaction with the LiOH produced via electrolysis to form more lithium carbonate.

[0058] Turning to FIG. 1 , reference is made to an exemplary carbon reduction process of the present disclosure for preparing lithium carbonate with carbon capture.

[0059] In an embodiment, as shown in FIG. 1 , panel (A), the present disclosure relates to a process for producing lithium carbonate with carbon capture, comprising: receiving a Li salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising LiOH; and delivering the product comprising LiOH and CO2 to a carbonate production reactor to produce lithium carbonate.

[0060] As used herein, the term “salt solution” refers to any aqueous solution of salts. The salt solution may be a naturally occurring solution, a synthetic solution, or asemi-synthetic solution. By “synthetic”, it is intended to mean that the salt solution was formed by combining individual ingredients (e.g. compounds, molecules, ions, etc.) to form the salt solution. By “semi-synthetic”, it is intended to mean that the salt solution is formed by adding one or more ingredients (e.g. compounds, molecules, ions, etc.) to a naturally occurring solution. The naturally occurring solution may already be a salt solution that is desired to be modified with other ingredients.

[0061] In an embodiment, the salt solution may be a produced water or brine that is extracted from an underground reservoir. By “produced water”, it is intended to mean a salt solution that is formed by delivering an aqueous fluid downhole to capture desirable components within the underground formation (e.g. lithium). By “brine”, it is intended to mean an existing underground aqueous solution containing desirable alkali metals. In an embodiment, the salt solution is a salar brine. In an embodiment, the salt solution may comprise LiCI, IJ2SO4, U3PO4, UNO3, Lil, LiBr, NaCI, Na2SC>4, NasPO4, NaNCh, Nal, NBr, KCI, K2SO4, K3PO4, KNO3, KI, KBr, or a combination thereof.

[0062] In the context of the processes herein for producing lithium carbonate, the salt solution is a Li salt-containing solution, such as a salt solution comprising LiCI, U2SO4, U3PO4, LiNOs, Lil, or LiBr. In an embodiment, the Li salt-containing solution is a produced water or a brine.

[0063] The processes herein comprise a step of receiving the Li salt-containing solution in an electrolysis cell comprising a cathode and an anode. The electrolysis cell may be any of any shape or form, such as any electrolysis cell as described herein. In an embodiment, the electrolysis cell is a membrane electrolysis cell. In an embodiment, the electrolysis cell is a membrane electrolysis cell comprising a gas diffusion electrode as described herein.

[0064] The Li salt-containing solution may be received into the electrolysis cell in any suitable manner. In an embodiment, the electrolysis cell comprises an inlet through which the salt solution is delivered into an interior space or compartment of the electrolysis cell. The inlet may be formed of a canal, a tubing, a conduit, a hole, an opening, or any combination thereof. The inlet may be capable of being opened and closed, fully or partially, to control the flow of salt solution into the electrolysis cell, such as for example in accordance with flow rates as described herein.

[0065] The processes herein comprise a step of applying an electric potential between the cathode and anode. The electrical potential is provided by delivering electrical power (i.e. electricity) to the electrolysis cell.

[0066] In an embodiment, the electrical power that is delivered to the electrolysis cell to apply the electrical potential between the cathode and the anode is from a power grid, a localized power generation unit (e.g. a turbine), a renewable energy source, or any other source of electrical power. In an embodiment, the electrical power may be exclusively from any one of these or other sources. In an embodiment, the electrical power may be from any combination or these and other sources.

[0067] Electrolysis within the electrolysis cell results in the formation of a base. As used herein, the term “base” is intended to have interchangeably meaning with “alkali metal compound” or “alkaline compound”, each referring to any chemical compound that comprises an alkali metal (e.g. Li, Na, K, Rb, Cs, or Fr) in combination or association with one or more negatively charged molecules or anions (e.g. OFT, CO32). In the context of the processes herein for producing lithium carbonate, the base is or comprises LiOH. The configuration and operation of the electrolysis cell to provide the base is described elsewhere herein. Generally, positive salt ions (Li+) of the salt solution move through the electrolysis cell and associate with OH- ions from a water or gas source, to form the base.

[0068] The base (LiOH) may be removed from the electrolysis cell in any suitable manner. In an embodiment, the electrolysis cell comprises an outlet through which the base able to pass through to exit the electrolysis cell. The outlet may be formed of a canal, a tubing, a conduit, a hole, an opening, or any combination thereof. The outlet may be capable of being opened and closed, fully or partially, to control the flow of the base out of the electrolysis cell.

[0069] Depending on the type and configuration of the electrolysis cell, positive ions of the salt solution (Li+) and negative ions of the water or gas (OH ) migrate to the same compartment (e.g. the base build-up compartment) and together form the base / alkaline compound (LiOH).

[0070] A by-product of the electrolysis process is a dilute salt solution. As used herein, by “dilute salt solution” it is intended to mean a salt solution that has a lower concentration of a particular alkali metal (e.g. lithium) than the input salt solution to theelectrolysis cell. The dilute salt solution may be discarded or may be used for another purpose. In an embodiment, the dilute salt solution is returned to an underground reservoir. In an embodiment, the dilute salt solution is added to the Li salt-containing solution to re-concentrate the Li salt-containing solution with any lithium that was not removed from the salt solution, to form base, in the prior pass through the electrolysis cell.

[0071] As shown in FIG. 1 , in the processes herein for producing lithium carbonate, the LiOH produced by the electrolysis cell is delivered and mixed with CO2. By way of a carbonation step, lithium carbonate is formed with water as the by-product:

[0072] The carbonation step may be performed in any suitable vessel, container or apparatus under any suitable conditions. In an embodiment, the LiOH and CO2 are mixed or combined in a carbonate production reactor. Reactors used to the production of carbonates are known, particularly in relation to the production of precipitated calcium carbonate (PCC). In an embodiment, the reactor employs a stirred tank reactor with a gas distributor. In such embodiment, gaseous CO2 is delivered to liquid base. The stirred tank reactor can be operated in batch or continuous mode. In an embodiment, the carbonate production reactor herein is a continuous mode reactor. Various types of mixers may be used to create a homogenous mixture of the LiOH suspension, lithium carbonate suspension, and gas bubbles created in the reaction system. Vertical baffles may be included in the tank to prevent vortex formation. Temperature can be controlled, for example, by use of a tank jacket in which circulating water at a constant temperature is pumped. The water used may be the by-product water produced during the carbonation reaction. Other types of carbonate production reactors include the Couette-Taylor reactor, spinning disc reactors (SDRs), rotating disc reactors (RDRs), microbubble systems (MBS), mineral carbonation reactors, and reactors with a microfiltration membrane.

[0073] The LiOH may be delivered from the electrolysis cell to the carbonate production reactor by any suitable means. In an embodiment, the carbonate production reactor is fluidly coupled to the electrolysis device, for example via an outlet on the electrolysis device. By “fluidly coupled to”, it is meant to refer to any configuration or arrangement of components that allow a liquid or gas to pass from one device or apparatus (e.g. electrolysis cell) to another device or apparatus (e.g. carbonate production reactor). Inan alternate embodiment, the LiOH is stored in a vessel or container and transported to the carbonate production reactor. In an embodiment, the transport is a short or long distance.

[0074] In an embodiment, the carbonate production reactor is fluidly coupled to a device or apparatus for providing CO2. In an embodiment, the device or apparatus for providing CO2 is a direct air capture system that is capable of removing CO2 from another substance (e.g. air, exhaust gas, etc.). Exemplary embodiments of direct air capture systems include, without limitation, those manufactured and sold by AirCapture, Capture6, CarbonCapture Inc., Carbon Collect Limited, Carbyon, Climeworks, CO2Rrail, Fervo Energy, Global Thermostat, Heirloom, Mission Zero Technologies, Noya, Orca, Removr, RepAir Carbon Capture, Skytree, Soletair Power, Sustaera, Valiidun, and Verdox.

[0075] In an embodiment, the carbonate production reactor itself comprises a CO2 sequestration apparatus or device. The CO2 sequestration apparatus or device may be any carbon capture technology or equipment.

[0076] For performing the processes as described herein for producing lithium carbonate with carbon capture, there is further provided a system comprising an electrolysis cell comprising a cathode and an anode; and a carbonate production reactor configured to receive a product comprising LiOH from the electrolysis cell and CO2 to generate lithium carbonate. The electrolysis cell may be any of any shape or form, such as any electrolysis cell as described herein. In an embodiment, the electrolysis cell is a membrane electrolysis cell. In an embodiment, the electrolysis cell is a membrane electrolysis cell comprising a gas diffusion electrode as described herein. The carbonate production reactor may be any such device or apparatus as described herein, or otherwise known.

[0077] In an embodiment, the system for lithium carbonate production further comprises a device or apparatus for providing the CO2 to the carbonate production reactor. In an embodiment, the device or apparatus for providing the CO2 is a direct air capture system, such as described herein. In an embodiment, the carbonate production reactor itself comprises a CO2 sequestration apparatus or device.

[0078] In an embodiment, the processes herein for producing lithium carbonate include an additional step to produce cathode active materials.

[0079] Thus, in an embodiment such as shown in FIG. 1 , panel (B), the present disclosure relates to a process of producing cathode active material with reduced carbon emissions, comprising: receiving a Li salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising LiOH; delivering the product comprising LiOH and CO2 to a carbonate production reactor to produce lithium carbonate; and mixing the lithium carbonate with precursor cathode active material to produce cathode active material.

[0080] As the skilled person will appreciate from the disclosure herein, the production of CAMs using the lithium carbonate produced by the processes herein is more environmentally-friendly than using other sources of lithium carbonate for producing CAMs. As discussed earlier herein, the production of CAMs emits CO2. However, by using the carbon-negative lithium carbonate herein, a producer can balance or offset their carbon emissions by using a starting material (Li2COa) that removed or captured CO2 from the air during its production. Moreover, provided it is environmentally conscious to do so, the CO2 produced during the production of CAMs could be delivered to the carbonate production reactor to make more carbon-negative lithium carbonate.

[0081] In addition to lithium carbonate, precursor cathode active materials (PCAMs) are required for the production of CAMs. These PCAM materials are well known and include, without limitation, mixed-metal hydroxides of nickel, manganese, cobalt and other chemical elements which, when combined with Li containing compounds, such as lithium carbonate, produce CAMs such as Lithium Nickel Cobalt Manganese Oxide (NMC), Lithium Iron Phosphate (LFO), Lithium Nickel Manganese Spinel (LMNO), Lithium Nickel Cobalt Aluminum Oxide (NCA), Lithium Manganese Oxide (LMO), and Lithium Cobalt Oxide (LOO).

[0082] As described herein, conventional processes for preparing CAMs results in significant emission of CO2. However, by employing the processes herein whereby the source of lithium for the production of CAMs is a carbon-negative lithium carbonate, the CO2 emission from CAM production can be at least partially offset.

[0083] Adding to the ability to offset CO2 emissions from CAM production, the present disclosure further provides a more environmentally friendly and sustainable process for preparing sodium carbonate.

[0084] Conventional production of Li2CO3involves the use of sodium carbonate (Na2CO3):

[0085] In these conventional methods, both of the starting materials are often sourced from rocky deposits or from brines that are rich in the compounds. For example, an important source of sodium carbonate used in these conventional processes is natural minerals, such as thermonatrite (sodium carbonate monohydrate; Na2CO3H2O) or natron (or natrite; sodium carbonate decahydrate; Na2CO3- 10H2O).

[0086] The production of CAMs using Li2CO3from conventional production results in emissions of carbon previously stored in mineral form. There exists a need for an alternative source of sodium carbonate that does not release previously stored carbon.

[0087] Advantageously, the present disclosure provides such a process whereby sodium carbonate may be produced from a different source. During conventional production of LiOH or Li2CO3, significant quantities of NaCI or Na2SC>4 are produced as by-products. These by-products are a waste stream to conventional processors, and steps must be taken to dispose of these waste by-products. However, by way of the processes disclosed herein, these previous waste by-products can be used as feedstock delivered to an electrolysis cell for conversion of NaCI or Na2SC>4 to NaOH. This sodium base can then be mixed with CO2to produce “carbon-negative” sodium carbonate. In such processes disclosed herein, the CO2is captured or removed a desired source (e.g. the air, exhaust gases, etc.), thereby reducing greenhouse gases and having an advantageously “carbon-negative” effect. For example, the carbon dioxide may be supplied by a direct air capture method.

[0088] Turning to FIG. 2, reference is made to an exemplary carbon reduction process of the present disclosure for preparing sodium carbonate with carbon capture.

[0089] In an embodiment, as shown in FIG. 2, panel (A), the present disclosure relates to a process for producing sodium carbonate with carbon capture, comprising: receiving a Na salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from theelectrolysis cell a product comprising NaOH; and delivering the product comprising NaOH and CO2 to a carbonate production reactor to produce sodium carbonate.

[0090] The term “salt solution” has the meaning described elsewhere herein. In the context of the processes for producing sodium carbonate, the salt solution is a Na salt-containing solution, such as a salt solution comprising NaCI, Na2SC>4, NaaPO^ NaNOa, Nal, or NaBr. In an embodiment, the Na salt-containing solution may be sourced from a waste by-product generated during the production of lithium hydroxide or lithium carbonate by conventional methods.

[0091] The processes herein comprise a step of receiving the Na salt-containing solution in an electrolysis cell comprising a cathode and an anode. The electrolysis cell may be any of any shape or form, such as any electrolysis cell as described herein. In an embodiment, the electrolysis cell is a membrane electrolysis cell. In an embodiment, the electrolysis cell is a membrane electrolysis cell comprising a gas diffusion electrode as described herein. The Na salt-containing solution may be received into the electrolysis cell in any suitable manner, such as for example those described herein for receiving a Li salt-containing solution.

[0092] The processes herein comprise a step of applying an electric potential between the cathode and anode. The electrical potential is provided by delivering electrical power (i.e. electricity) to the electrolysis cell, such as described elsewhere herein.

[0093] Electrolysis within the electrolysis cell results in the formation of a base, as described elsewhere herein. In the context of the processes herein for producing sodium carbonate, the base is or comprises NaOH. The configuration and operation of the electrolysis cell to provide the base is described elsewhere herein. Generally, positive salt ions (Na+) of the salt solution move through the electrolysis cell and associate with OH- ions from a water or gas source, to form the base.

[0094] The base (NaOH) may be removed from the electrolysis cell in any suitable manner, such as for example those described elsewhere herein for removing LiOH.

[0095] Depending on the type and configuration of the electrolysis cell, positive ions of the salt solution (Na+) and negative ions of the water or gas (OH ) migrate to the samecompartment (e.g. the base build-up compartment) and together form the base / alkaline compound (NaOH).

[0096] A by-product of the electrolysis process is a dilute salt solution. In an embodiment, the dilute salt solution is returned to an underground reservoir or a body of water (e.g. ocean). In an embodiment, the dilute salt solution is added to the Na salt-containing solution to re-concentrate the Na salt-containing solution with any sodium that was not removed from the salt solution, to form base, in the prior pass through the electrolysis cell.

[0097] As shown in FIG. 2, in the processes herein for producing sodium carbonate, the NaOH produced by the electrolysis cell is delivered and mixed with CO2. By way of a carbonation step, sodium carbonate is formed with water as the by-product:

[0098] The carbonation step may be performed in any suitable vessel, container or apparatus under any suitable conditions. In an embodiment, the NaOH and CO2 are mixed or combined in a carbonate production reactor, such as those described elsewhere herein.

[0099] The NaOH may be delivered from the electrolysis cell to the carbonate production reactor by any suitable means. In an embodiment, the carbonate production reactor is fluidly coupled to the electrolysis device, for example via an outlet on the electrolysis device. In an alternate embodiment, the NaOH is stored in a vessel or container and transported to the carbonate production reactor. In an embodiment, the transport is a short or long distance.

[0100] In an embodiment, the carbonate production reactor is fluidly coupled to a device or apparatus for providing CO2, such as for example in any manner and to any device or apparatus as described elsewhere herein. In an embodiment, the carbonate production reactor itself comprises a CO2 sequestration apparatus or device. The CO2 sequestration apparatus or device may be any carbon capture technology or equipment.

[0101] For performing the processes as described herein for producing sodium carbonate with carbon capture, there is further provided a system comprising an electrolysis cell comprising a cathode and an anode; and a carbonate production reactor configured to receive a product comprising NaOH from the electrolysis cell and CO2 to generate sodiumcarbonate. The electrolysis cell may be any of any shape or form, such as any electrolysis cell as described herein. In an embodiment, the electrolysis cell is a membrane electrolysis cell. In an embodiment, the electrolysis cell is a membrane electrolysis cell comprising a gas diffusion electrode as described herein. The carbonate production reactor may be any such device or apparatus as described herein, or otherwise known.

[0102] In an embodiment, the system for sodium carbonate production further comprises a device or apparatus for providing the CO2 to the carbonate production reactor. In an embodiment, the device or apparatus for providing the CO2 is a direct air capture system, such as described herein. In an embodiment, the carbonate production reactor itself comprises a CO2 sequestration apparatus or device.

[0103] In an embodiment, the processes herein for producing sodium carbonate include an additional step to produce lithium carbonate.

[0104] Thus, in an embodiment such as shown in FIG. 2, panel (B), the present disclosure relates to a process for producing lithium carbonate with carbon capture, comprising: receiving a Na salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising NaOH; delivering the product comprising NaOH and CO2 to a carbonate production reactor to produce sodium carbonate; and mixing the sodium carbonate with a Li salt-containing solution to produce lithium carbonate by way of a precipitation reaction. In an embodiment, the Li salt-containing solution is LiCI or Li2SO4.

[0105] In an embodiment, the lithium carbonate produced by the processes herein involving chemical precipitation of lithium salts with carbon-negative sodium carbonate can be used as a precursor material for the production of CAMs as described herein, thus again providing a carbon-negative source of lithium carbonate via a carbon-negative source of sodium carbonate.

[0106] Moreover, as shown in FIG. 2, panel (B), in embodiments herein the byproduct of producing lithium carbonate from carbon-negative sodium carbonate is NaCI or Na2SO4. Advantageously, these by-products can be recycled and used as the feedstock Na salt-containing solution in preparing the carbon-negative sodium carbonate in accordancewith the processes herein. This feedback loop further improves the carbon reduction potential of the processes of the present disclosure.

[0107] Adding again to the ability to offset CO2 emissions in the context of battery production, the present disclosure contemplates yet another use of Na salt-containing solutions, including those produced by the processes herein involving the precipitation of carbon-negative sodium carbonate to lithium carbonate. In particular, Na salt-containing solutions, including those produced in accordance with FIG. 2, panel (B), may be used in processes disclosed herein (e.g. FIG. 3) for ocean alkalinity enhancement (OAE) or increasing the alkalinity of any body of water, to thereby improve carbon dioxide removal (CDR) from the air.

[0108] The ocean is one of Earth's largest natural carbon sinks. It naturally absorbs roughly one-third of fossil fuel emissions humans produce each year, making it a natural medium for CDR.

[0109] Carbon dioxide dissolves in ocean water and may form H2CO3, HCOa", and CO32' as depicted in the following equilibrium reactions:

[0110] Carbonic acid (H2CO3) rapidly dissociates to produce bicarbonate ions (HCO3 ). There is so little carbon in the form of carbonic acid (H2CO3) at any one moment in time that the concentrations of CO2 and H2CO3 are usually combined as CO2.

[0111] The equilibria of the above species may be shifted by adjusting the pH of the water. For example, lower pH will cause the equilibria to shift towards the left resulting in higher concentrations of CO2 which may be emitted from the water. Conversely, increasing pH (i.e. alkalinity enhancement) will cause the equilibria to shift to the right resulting in higher concentrations of bicarbonate and carbonate while increasing the water’s capacity to absorb CO2.

[0112] In view of the above, ocean acidification may contribute to increased CO2 in the atmosphere. A possible solution to ocean acidification is OAE allowing more carbon dioxide to be absorbed into this natural sink. This may be accomplished by adding alkaline substances to seawater to enhance the ocean’s natural carbon sink.

[0113] The conventional lithium refining industry produces by-products that may be converted into alkaline substances for OAE allowing for responsible disposal of by-product while achieving carbon reduction. For example, evaporation ponds used in concentrating salar brines produce NaCI as a by-product. Hard rock and clay operations produce Na2SC>4 as by-product following a precipitation step. In addition, embodiments herein for producing lithium carbonate from carbon-negative sodium carbonate result in NaCI and / or Na2SC>4 by-products.

[0114] In accordance with the present disclosure, the NaCI or Na2SC>4 by-products may be used as feedstock for a process using an electrolysis cell for conversion to NaOH. The resulting NaOH would be added to seawater for OAE.

[0115] Turning to FIG. 3, reference is made to an exemplary process herein for enhancing ocean alkalinity. In an embodiment, the present disclosure relates to a process for enhancing ocean alkalinity, comprising: receiving a salt solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising an alkaline compound; and delivering the product comprising an alkaline compound to a body of seawater.

[0116] The term “salt solution” has the meaning described elsewhere herein. In the context of the processes for enhancing ocean alkalinity, the salt solution is preferably a Na salt-containing solution, such as a salt solution comprising NaCI, Na2SC>4, Na3PO4, NaNOa, Nal, or NaBr. In an embodiment, the Na salt-containing solution is sourced from a waste by-product generated during the production of lithium hydroxide or lithium carbonate by conventional methods (e.g. NaCI or Na2SC>4 to NaOH). In an embodiment, the salt solution is sourced from by-products of the processes herein for producing lithium carbonate from carbon-negative sodium carbonate.

[0117] In an embodiment of the processes herein for enhancing ocean alkalinity, the salt solution comprises NaCI. In an embodiment, the NaCI is a by-product from a solar evaporation pond in a lithium brine extraction operation. In an embodiment, the NaCI is a by-product of the processes herein for producing lithium carbonate from carbon-negative sodium carbonate (FIG. 2, panel (B)).

[0118] In an embodiment of the processes herein for enhancing ocean alkalinity, the salt solution comprises Na2SO4. In an embodiment, the Na2SO4 is a by-product from a lithiumsulfate to lithium hydroxide or lithium carbonate conversion operation. In an embodiment, the Na2SC>4 is a by-product of the processes herein for producing lithium carbonate from carbon-negative sodium carbonate (FIG. 2, panel (B)).

[0119] The processes herein comprise a step of receiving the salt-containing solution in an electrolysis cell comprising a cathode and an anode. The electrolysis cell may be any of any shape or form, such as any electrolysis cell as described herein. In an embodiment, the electrolysis cell is a membrane electrolysis cell. In an embodiment, the electrolysis cell is a membrane electrolysis cell comprising a gas diffusion electrode as described herein. In an embodiment, the electrolysis cell is a 5-compartment electrolysis cell as described herein.

[0120] The salt-containing solution may be received into the electrolysis cell in any suitable manner, such as for example those described herein for receiving Li salt-containing solutions and Na salt-containing solutions.

[0121] The processes herein for enhancing ocean alkalinity comprise a step of applying an electric potential between the cathode and anode. The electrical potential is provided by delivering electrical power (i.e. electricity) to the electrolysis cell, such as described elsewhere herein.

[0122] Electrolysis within the electrolysis cell results in the formation of a base, as described elsewhere herein. In the context of the processes using Na salt-containing solutions, the base is or comprises NaOH. The configuration and operation of the electrolysis cell to provide the base is described elsewhere herein. Generally, positive salt ions (Na+) of the salt solution move through the electrolysis cell and associate with OH- ions from a water or gas source, to form the base. Depending on the type and configuration of the electrolysis cell, positive ions of the salt solution (Na+) and negative ions of the water or gas (OH ) migrate to the same compartment (e.g. the base build-up compartment) and together form the base / alkaline compound (NaOH).

[0123] The base (NaOH) may be removed from the electrolysis cell in any suitable manner, such as for example those described elsewhere herein for removing. In accordance with the processes herein (e.g. FIG. 3), the resulting NaOH would be delivered and added to seawater or any other body of water for OAE. The resulting base (e.g. NaOH) may be delivered to an ocean or other body of water by any suitable means. In an embodiment, thebase / alkaline compound is flowed directly to or is shipped to a body of water (e.g. ocean seawater).

[0124] A by-product of the electrolysis process is a dilute salt solution. In an embodiment, the dilute salt solution is added to the Na salt-containing solution to re-concentrate the Na salt-containing solution with any sodium that was not removed from the salt solution, to form base, in the prior pass through the electrolysis cell.

[0125] For performing the processes as described herein for enhancing ocean alkalinity, there is further provided a system comprising an electrolysis cell comprising a cathode and an anode. The electrolysis cell may be any of any shape or form, such as any electrolysis cell as described herein. In an embodiment, the electrolysis cell is a membrane electrolysis cell. In an embodiment, the electrolysis cell is a membrane electrolysis cell comprising a gas diffusion electrode as described herein. In an embodiment, the electrolysis cell is a 5-compartment electrolysis cell as described herein.

[0126]

[0127] Electrolysis Cells

[0128] The term “electrolysis cell” refers to any device comprising an anode and a cathode, whereby electrons move in response to an electrical energy or current being supplied to facilitate chemical reactions within the electrolysis cell. An electrolysis cell is a type of electrochemical cell that generates a chemical reaction via electrolysis.

[0129] In an embodiment, the electrolysis cell is an electrodialysis cell or a membrane electrolysis cell, these terms used interchangeably herein. As the skilled person will appreciate, an electrodialysis cell is a form of an electrolysis cell that can be used to transport salts from one solution or compartment to another. An electrodialysis cell comprises one or more membranes separating different compartments of the electrodialysis cell. Using an electrodialysis cell, electrolysis is used to transport salt ions from one solution or compartment through ion-exchange membranes to another solution or compartment under the influence of an applied electric potential difference.

[0130] In an embodiment, the membrane electrolysis cell may comprise one compartment, two compartments, three compartments, four compartments, five compartments, or more. The compartments may, for example be separated by membranesand / or diaphragms. In an embodiment, one or more compartments of the membrane electrolysis cell comprise an anode compartment, an acid build-up compartment, a salt depletion compartment, a base build-up compartment, a cathode compartment, or any combination thereof. The “anode compartment” is the compartment comprising an anode. The “cathode compartment” is the compartment comprising the cathode. The “salt-depletion compartment” is a compartment from which salts from the salt solution are removed. The “acid build-up compartment” is a compartment in which acidic species or solutions reside and can be obtained upon operation. The “base build-up compartment” is a compartment in which basic species or solutions reside and can be obtained upon operation. For example, the base build-up compartment may comprise the desired alkali metal compounds of the present disclosure. In a particular embodiment, the membrane electrolysis cell comprises four compartments or five compartments.

[0131] In an embodiment, the electrolysis cell may be a chlor-alkali membrane electrolysis cell (see FIG. 4) or a chlor-alkali diaphragm electrolysis cell (see FIG. 5). As shown in FIG. 4, a chlor-alkali membrane electrolysis cell comprises a cation exchange membrane (GEM). The GEM permits the passage of cations, such as Li+, Na+, etc., through the membrane while preventing passage of other substances, including the salt solution. In contrast, as shown in FIG. 5, a chlor-alkali diaphragm comprises a membrane or diaphragm that is semi-permeable and allows both the cations and the salt solution to pass through. With a salt solution comprising LiCI, both of these electrolysis cells allow for the formation of LiOH, but with the chlor-alkali membrane cell the base (e.g. LiOH) is in aqueous solution whereas with the chlor-alkali diaphragm the base (e.g. LiOH) is in dilute salt solution. Both of these types of electrolysis cells produce hydrogen (H2) as a by-product.

[0132] In another embodiment, the electrolysis cell may be an electrodialysis cell that comprises both a GEM and an anion exchange membrane (AEM), such as for example shown in FIG. 6. The embodiment shown in FIG. 6 is an electrolysis cell having three compartments, each compartment separated by a membrane. In other embodiments, the electrolysis cell may have four compartments, five compartments, or more. Different configurations may be used to obtain different outputs and / or utilize different inputs / feedstocks.

[0133] Exemplary embodiments of AEMs and CEMs that may be used in the context of the present disclosure are described elsewhere herein.

[0134] In an embodiment, the electrolysis cell may be an electrodialysis cell that comprises at least one bipolar membrane (BPM), also referred to herein as a bipolar membrane electrodialysis cell. An exemplary embodiment is shown in FIG. 7. As used herein, by “bipolar membrane” it is intended to mean a membrane that is used to split water. In an embodiment, the BPM is a sandwich of a GEM and an AEM to form a single BPM. Since a BPM allows both anions and cations to pass, these membranes are not typically considered to split the electrodialysis cell into different compartments.

[0135] In an embodiment, the electrolysis cell may comprise a single BPM separating one or more OEMs and / or AEMs on either side. For example, in an embodiment the electrolysis cell may comprise the following arrangement of membranes: AEM-CEM-BPM- AEM-CEM.

[0136] In an embodiment, the electrolysis cell may comprise two BPMs separated by a GEM (e.g. BPM-CEM-BPM; see FIG. 7). In an embodiment, the electrolysis cell may comprise two bipolar membranes separated by an AEM (e.g. BPM-AEM-BPM; see FIG. 8). In an embodiment, the electrolysis cell may comprise two bipolar membranes separated by an AEM and a GEM (e.g. BPM-AEM-CEM-BPM; see FIG. 9). Repeating units of any of these configurations within an electrolysis cell is contemplated and encompassed herein, such as for example BPM-CEM-BPM-CEM-BPM.

[0137] In an embodiment, the electrolysis cell is a membrane electrolysis cell that comprises a gas diffusion electrode (“GDE”) in the cathode compartment. In a particular embodiment of the membrane electrolysis cell, the membrane electrolysis cell comprises the GDE as the cathode in the cathode compartment.

[0138] The GDE comprises a porous catalyst layer which is disposed on a carrier material. The catalyst layer, which conducts electrons, catalyses an electrochemical reaction between a liquid and a gas. Thus, the electrochemical reaction occurs at a so-called three-phase boundary where gas, liquid and solid ( .e. catalyst) are contacted.

[0139] In an embodiment, the gas may comprise oxygen and the liquid may comprise water resulting in the cathodic reaction:O2+ 2H2O + 4e- -► 4OH-

[0140] In this case, the GDE allows for a membrane electrolysis cell to operate using air as the oxygen source at the cathode. This may be a significant economic and safety advance in the ability to incorporate these cells into a process for producing a base (e.g. alkali metal compounds such as alkali metal hydroxides).

[0141] In a further embodiment, the gas may comprise oxygen admixed with carbon dioxide resulting in the following cathodic reactions:O2+ 2H2O + 4e- -► 4OH-OH- + CO2 -► HCO3-HCO3- + OH- -► CO32- + H2O

[0142] In this embodiment, it may be possible to electrochemically produce alkali metal carbonates and bicarbonates.

[0143] Various embodiments of GDEs in accordance with the present disclosure are described below by reference to “GDE-1", “GDE-2" and “GDE-3". Non-limiting configurations of these GDE embodiments are shown in FIG. 10 (GDE-1), FIG. 11 (GDE-2 , FIG. 12 (GDE-3) and FIG. 13 (GDE-4).

[0144] As will be appreciated by the skilled person having regard to the present disclosure, the GDEs may be prepared by any of the numerous methods known in the art for applying a catalyst layer to a substrate (e.g. GDL or membrane). The form of the catalyst layer preparation will influence the choice of method. For example, solid / powder (e.g. dry powder spraying, decal method), suspension (e.g. Doctor Blade, screen printing, inkjet printing, scrape method), aerosol (e.g. sonicated spray, irradiation spray, hand brush air spray), vapour / plasma (e.g. magnetron sputtering, decal sputtering, helican RF sputtering, chemical vapour deposition), electrode assisted deposition (e.g. electrode spraying, electrodeposition, or electrophoretic deposition). In an embodiment, the catalyst layer is a suspension and may be applied by way of, for example and without limitation, Doctor Blade, screen printing, inkjet printing, or scrape method.GDE-1

[0145] In an aspect of the present disclosure, there is provided a gas diffusion electrode (GDE-1 ) comprising a gas diffusion layer (GDL) and a catalyst layer (CL). In an embodiment, the CL is disposed on a surface of the GDL. See, for example, FIG. 10(a).

[0146] In another embodiment, the GDL of GDE-1 may be modified with a hydrophobic polymer treatment and / or application of a microporous layer (MPL). In an embodiment, the GDE further comprises the MPL disposed on a surface of the GDL, wherein the CL is disposed on a surface of the microporous layer opposite the GDL. See, for example, FIG. 10(b).

[0147] In yet another embodiment, GDE-1 may include a mesh in contact with a surface of the GDL opposite from the CL (see, for example, FIG. 10(c)) or opposite from the MPL (see, for example, FIG. 10(d)). In an embodiment, the mesh is bonded to the GDL by teflonization, hot-pressing, or lamination.

[0148] In still another embodiment, GDE-1 includes an anion exchange membrane (AEM) which may assist in the prevention of GDE flooding by the liquid reactant in an electrolysis cell. In an embodiment, the AEM may be disposed on a surface of the CL, the AEM being configured to exchange ions from the catalyst layer to an opposed surface of the AEM. See, for example, FIGs. 10(e)-1 (h). The AEM may be held in direct contact with the CL through a mechanical means or the AEM is bonded to the CL, for example, by teflonization, hot-pressing, ionomer, or lamination.GDE-2

[0149] In another aspect of the present disclosure, there is provided a gas diffusion electrode (GDE-2) comprising a gas diffusion layer (GDL) and a catalyst coated membrane (CCM). In an embodiment, the CL is disposed on a surface of a membrane to form the CCM. See, for example, see FIG. 1 1 (a).

[0150] In an embodiment, the CCM refers to the anion exchange membrane having one surface coated with the CL. The CCM may allow for better ion transport through the contact interface between the CL and membrane. In an embodiment, the GDL is in contact with the CL of the CCM.

[0151] In another embodiment, the GDL of GDE-2 may be modified with a hydrophobic polymer treatment and / or application of a microporous layer (MPL). In an embodiment, the GDE further comprises the MPL disposed on a surface of the GDL, wherein the MPL is in contact with the CL of the CCM. See, for example, FIG. 11 (b).

[0152] In yet another embodiment, GDE-2 may include a mesh in contact with a surface of the GDL opposite from the CL (see, for example, FIG. 1 1 (c)) or opposite from the MPL (see, for example, FIG. 1 1 (d)). In an embodiment, the mesh is bonded to the GDL by teflonization, hot-pressing, or lamination.GDE-3

[0153] In another aspect of the present disclosure, there is provided a gas diffusion electrode (GDE-3) comprising a gas diffusion layer (GDL) and a catalyst layer (CL) disposed on the GDL, wherein the catalyst layer has a thickness (T) optimized to substantially or completely consume a liquid reactant diffusing across the CL before reaching the GDL. See, for example, see FIG. 12(a).

[0154] As the liquid reactant diffuses across the CL of GDE-3, it will be consumed due to electrochemical reaction. Consequently, a concentration gradient of the reacting species will develop across the depth of the CL. In an embodiment, the final concentration of the liquid reactant may be zero or near zero at the interface between the CL and GDL. By “near zero”, it is meant a moisture content at the interface between the CL and the GDL that is of an amount insufficient to adversely affect the electrochemical reaction of the GDE. In an embodiment, the moisture content at the surface of the CL at the interface between the CL and GDL is an amount less than 5%, less than 4%, less than 3%, less than 2%, less than 1 % of the liquid reactant. By controlling the thickness, and optionally the hydrophobicity and / or porosity of the CL, one may control the concentration gradient to ensure more complete utilization of the reactant. With sufficient reaction of the liquid reactant in the CL, use of an ion exchange membrane with GDE-3 may be rendered unnecessary in an electrolysis cell.

[0155] In an embodiment, GDE-3 may include a mesh in contact with a surface of the GDL opposite from the CL (see, for example, FIG. 12(b)). In an embodiment, the mesh is bonded to the GDL by teflonization, hot-pressing, or lamination.GDE-4

[0156] In an aspect of the present disclosure, there is provided a gas diffusion electrode (GDE-4) comprising a first gas diffusion layer (1stGDL), a catalyst layer (CL), a second gas diffusion layer (2ndGDL), an ionomer layer (IL), and an anion exchange membrane (AEM). In an embodiment, the CL is disposed on a surface of the 1stGDL. In another embodiment, a surface of the 2ndGDL is in contact with the CL. In a further embodiment, the IL is bonded to the AEM. In yet a further embodiment, the IL is in contact with a surface of the 2ndGDL opposite from the CL. See, for example, FIG. 13(a).

[0157] In another embodiment, the 2ndGDL of GDE-4 may be modified with a hydrophobic polymer treatment and / or application of a microporous layer (MPL). In an embodiment, the GDE further comprises the MPL disposed on a surface of the 2ndGDL. In this embodiment, the MPL is in contact with the CL. See, for example, FIG. 13(b).

[0158] In yet another embodiment, GDE-4 may include a mesh in contact with a surface of the 1stGDL opposite from the CL (see, for example, FIG. 13(c) or (d)).

[0159] As described, the GDE-4 comprises a 1stGDL and a 2ndGDL. In an embodiment, the 1stGDL and 2ndGDL in the GDE-4 are the same. In another embodiment, the 1stGDL and 2ndGDL in the GDE-4 are different from each other. For example, the 1stGDL and 2ndGDL may have the same or different pore configurations, have the same or different porosity, be the same or different thickness, be made of the same or different materials (e.g. any of (1a)-(5f) described herein), be modified or not with a hydrophobic polymer treatment and / or application of a microporous layer, or any combination thereof selected independently for each of the 1stGDL and the 2ndGDL.

[0160] The surfaces of any of the GDEs described herein may have an embossed / debossed pattern to effectively increase the active surface area. The pattern may be applied to the GDEs by any known method including carving, molding and stamping. The pattern may be any suitable pattern that increases the surface area of the substrate or material.

[0161] Embodiments of various features of the above-described GDEs will now be described in further detail, such as the GDL, MPL, and CL.Gas Diffusion Layer (GDL)

[0162] The GDL is a porous structure that may act as a gas diffuser and / or a current collector. In an embodiment, the GDL may have relatively uniform pore size through its thickness. In another embodiment, the GDL may have a random pore size through its thickness. In yet another embodiment, the GDL may have a pore size gradient through its thickness. For example, the GDL may have a gradient of large to small pore size through its thickness in the direction of gas flow. Alternatively, the GDL may have a gradient of small to large pore size through its thickness in the direction of gas flow.

[0163] The GDL may have a thickness of between 50 pm and 1000 pm, between 50 pm and 950 pm, between 50 pm and 900 pm, between 50 pm and 850 pm, between50 pm and 800 pm, between 50 pm and 750 pm, between 50 pm and 700 pm, between50 pm and 650 pm, between 50 pm and 600 pm, between 50 pm and 550 pm, between50 pm and 500 pm, between 50 pm and 450 pm, between 50 pm and 400 pm, between50 pm and 350 pm, between 50 pm and 300 pm, between 50 pm and 250 pm, between50 pm and 200 pm, between 50 pm and 150 pm, between 50 pm and 100 pm, between100 pm and 1000 pm, between 150 pm and 1000 pm, between 200 pm and 1000 pm, between 250 pm and 1000 pm, between 300 pm and 1000 pm, between 350 pm and 1000 pm, between 400 pm and 1000 pm, between 450 pm and 1000 pm, between 500 pm and 1000 pm, between 550 pm and 1000 pm, between 600 pm and 1000 pm, between 650 pm and 1000 pm, between 700 pm and 1000 pm, between 750 pm and 1000 pm, between 800 pm and 1000 pm, between 850 pm and 1000 pm, between 900 pm and 1000 pm, between 950 pm and 1000 pm, between 100 pm and 950 pm, between 150 pm and 900 pm, between 200 pm and 850 pm, between 250 pm and 800 pm, between 300 pm and 750 pm, between 350 pm and 700 pm, between 400 pm and 650 pm, between 450 pm and 600 pm, between 500 pm and 550 pm, between 200 pm and 400 pm, between 210 pm and 390 pm, between 220 pm and 380 pm, between 230 pm and 370 pm, between 240 pm and 360 pm, between 250 pm and 350 pm, between 260 pm and 340 pm, between 270 pm and 330 pm, between 280 pm and 320 pm, or between 290 pm and 310 pm.

[0164] The GDL may have an average pore diameter of between 1 pm and 100 pm, between 1 pm and 90 pm, between 1 pm and 80 pm, between 1 pm and 70 pm, between 1 pm and 60 pm, between 1 pm and 50 pm, between 1 pm and 40 pm, between 1 pm and 30 pm, between 1 pm and 20 pm, or between 1 pm and 10 pm.

[0165] The GDL may have a porosity of between 50% and 95%, between 50% and 90%, between 50% and 85%, between 50% and 80%, between 50% and 75%, between 50% and 70%, between 50% and 65%, between 50% and 60%, between 50% and 55%, between 55% and 95%, between 60% and 95%, between 65% and 95%, between 70% and 95%, between 75% and 95%, between 80% and 95%, between 85% and 95%, between 90% and 95%. between 55% and 90%, between 60% and 85%, between 65% and 80%, or between 70% and 75%.

[0166] The GDL may comprise carbon-fibre paper, carbon cloth, carbon felt, carbon foam, metal mesh, metal foam, or any combination thereof. The GDL may be modified with a hydrophobic polymer treatment and / or application of a microporous layer (MPL).

[0167] Non-limiting examples of carbon-fibre paper include:(la) Toray TGP-H carbon-fibre paper (e.g. TGP-H-030, TGP-H-060, TGP-H-090, TGP-H-120),(l b) AvCarb® carbon-fibre paper (e.g. MGL190, MGL280, MGL370, MGL190T, MGL280T, MGL370T, EP40, EP40T, EP55, EP55T, GDS1 120, GDS2120, GDS22100, GDS2230, GDS2240, GDS3215, GDS3250, GDS3260, GDS5130, MB30, P50, P50T, P75, P75T),(lc) Spectracarb™ carbon-fibre paper (e.g. 2050A-0850, 2050A-1050, 2050A- 1535, 2050A-1550, 2050A-1550 Treated),(ld) Freudenberg carbon-fibre paper (e.g. H14, H14C7, H14C9, H14C10, H14Cx653, H15, H15C13, H15C14, H23, H23C2, H23C3, H23C5, H23C6, H23C7, H23C8, H23C9, H23Cx653, H23I2),(le) Sigracet® carbon-fibre paper (e.g. 22 BB, 25 BA, 25 BC, 28 AA, 28 BC, 29 AA, 29 BC, 36 AA, 36BB, 39 AA, 39 BB),(lf) CeTech carbon-fibre paper (e.g. GDS180S, GDS210, GDS230, GDS 250, GDS310, GDL240, GDL280, GDL340, GDS090S, GDS180HT, GDL120, GDL210SHT),(lg) JNT carbon-fibre paper series (e.g. JNT15B, JNT17B, JNT18B, JNT20, JNT21 , JNT30),(lh) LINQCELL carbon-fibre paper (e.g. GDP180, GDP210, GDP210-MP, GDP-210MPS, GDP 240, GDP340), and(11) Mitsubishi Chemicals PYROFIL™ GDL.

[0168] Non-limiting examples of carbon cloth include:(2a) AvCarb® carbon cloth (e.g. 1071 , 1698, 1209, 1185, 1186, 7497, T1819, T1820, T1824),(2b) E-TEK carbon cloth (e.g. CC4, CC4 Wet Proofed, CC6, CC6 Wet Proofed, ELAT plain cloth, ELAT LT1400, ELAT LT2400W),(2c) CeTech carbon cloth (e.g. W0S1009, W0S1011, W0S1011 , W1S1011),(2d) Zoltek™ Panex carbon cloth (e.g. PW03, PW06, SW08),(2e) LINQCELL carbon cloth (e.g. CF350, CF400-MP), and(2f) SAATI SCCG carbon cloth (e.g. 5N).

[0169] Non-limiting examples of carbon felt include:(3a) AvCarb® felt (e.g. C100, C200, C280, G100, G200, G300A, G475A, G600A),(3b) CeTech felt (e.g. CF120, GF20, GF100), and(3c) JNT felt (e.g. GF051 BH, GF061 AH).

[0170] Non-limiting examples of the metal foam include:(4a) nickel foam,(4b) copper foam,(4c) titanium foam,(4d) silver foam,(4e) stainless steel foam,(4f) iron nickel foam,(4g) nickel copper foam, and(4h) cobalt foam.

[0171] Non-limiting examples of the metal mesh include:(5a) copper metal mesh,(5b) nickel metal mesh,(5c) titanium metal mesh,(5d) silver metal mesh,(5e) stainless steel metal mesh, and(5f) molybdenum metal mesh.

[0172] The skilled person, having regard to the present disclosure, will be well aware of other suitable materials and configurations of the GDL, including as described further herein.Hydrophobic polymeric treatment of GDL

[0173] In an embodiment, the GDL may be modified with a hydrophobic polymer. A GDL modified with a hydrophobic polymer treatment involves the application of a hydrophobic additive to the GDL to control the wettability of the GDL.

[0174] Non-limiting examples of such hydrophobic additives include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), fluorinated ethylene propylene (FEP), perfluoropolyether (PFPE), and polydimethylsiloxane (PDMS). The GDL may be modified with any one or any combination of hydrophobic additives.

[0175] The GDL may comprise no hydrophobic addition or between 0.01 wt% and 50 wt%, between 0.01 wt% and 45 wt%, between 0.01 wt% and 40 wt%, between 0.01 wt%and 35 wt%, between 0.01 wt% and 30 wt%, between 0.01 wt% and 25 wt%, between 0.01 wt% and 20 wt%, between 0.01 wt% and 15 wt%, between 0.01 wt% and 10 wt%, between 0.01 wt% and 5 wt%, between 5 wt% and 50 wt%, between 10 wt% and 50 wt%, between 15 wt% and 50 wt%, between 20 wt% and 50 wt%, between 25 wt% and 50 wt%, between 30 wt% and 50 wt%, between 35 wt% and 50 wt%, between 40 wt% and 50 wt%, between 45 wt% and 50 wt%, between 5 wt% and 45 wt%, between 10 wt% and 40 wt%, between 15 wt% and 35 wt%, between 20 wt% and 30 wt%, between 25 wt% and 45 wt%, or between 30 wt% and 40 wt% of the hydrophobic additive.Microporous Layer (MPL)

[0176] The MPL is disposed on the GDL and may aid with electrical conductivity and / or water management.

[0177] The MPL comprises a particulate material coated on a planar face of the GDL. Any suitable particular material may be used. In an embodiment, the particulate material may be a mixture of carbon black and a hydrophobic polymer such as polytetrafluoroethylene (PTFE).

[0178] The MPL may comprise between 50 wt% and 95 wt%, between 55 wt% and 95 wt%, between 60 wt% and 95 wt%, between 65 wt% and 95 wt%, between 70 wt% and95 wt%, between 75 wt% and 95 wt%, between 80 wt% and 95 wt%, between 85 wt% and95 wt%, between 90 wt% and 95 wt%, between 60 wt% and 90 wt%, between 60 wt% and85 wt%, between 60 wt% and 80 wt%, between 60 wt% and 75 wt%, between 60 wt% and70 wt%, between 60 wt% and 65 wt%, between 65 wt% and 90 wt%, between 70 wt% and85 wt%, or between 75 wt% and 80 wt% of carbon black.

[0179] The MPL may comprise between 5 wt% and 50 wt%, between 5 wt% and 45 wt%, between 5 wt% and 40 wt%, between 5 wt% and 35 wt%, between 5 wt% and30 wt%, between 5 wt% and 25 wt%, between 5 wt% and 20 wt%, between 5 wt% and15 wt%, between 5 wt% and 10 wt%, between 10 wt% and 40 wt%, between 15 wt% and 40 wt%, between 20 wt% and 40 wt%, between 25 wt% and 40 wt%, between 30 wt% and40 wt%, between 35 wt% and 40 wt%, between 10 wt% and 35 wt%, between 15 wt% and30 wt%, or between 20 wt% and 25 wt% of the hydrophobic polymer.

[0180] The MPL may have a thickness of between 10 pm and 100 pm, between 10 pm and 90 pm, between 10 pm and 80 pm, between 10 pm and 70 pm, between 10 pm and 60 pm, between 10 pm and 50 pm, between 10 pm and 40 pm, between 10 pm and 30 pm, between 10 pm and 20 pm, between 20 pm and 100 pm, between 30 pm and 100 pm, between 40 pm and 100 pm, between 50 pm and 100 pm, between 60 pm and 100 pm, between 70 pm and 100 pm, between 80 pm and 100 pm, between 90 pm and 100 pm, between 20 pm and 90 pm, between 30 pm and 80 pm, between 40 pm and 70 pm, or between 50 pm and 60 pm.

[0181] The MPL may have an average pore diameter of between 0 pm and 10 pm, between 0 pm and 9 pm, between 0 pm and 8 pm, between 0 pm and 7 pm, between 0 pm and 6 pm, between 0 pm and 5 pm, between 0 pm and 4 pm, between 0 pm and 3 pm, between 0 pm and 2 pm, between 0 pm and 1 pm, between 0 pm and 0.9 pm, between 0 pm and 0.8 pm, between 0 pm and 0.7 pm, between 0 pm and 0.6 pm, between 0 pm and 0.5 pm, between 0 pm and 0.4 pm, between 0 pm and 0.3 pm, between 0 pm and 0.2 pm, or between 0 pm and 0.1 pm.

[0182] The MPL may have a porosity of between 30% to 75%, between 30% to 70%, between 30% to 65%, between 30% to 60%, between 30% to 55%, between 30% to 50%, between 30% to 55%, between 30% to 50%, between 30% to 45%, between 30% to 40%, between 30% to 35%, between 35% to 75%, between 40% to 75%, between 45% to 75%, between 50% to 75%, between 55% to 75%, between 60% to 75%, between 65% to 75%, or between 70% to 75%.Catalyst Layer (CL)

[0183] The catalyst layer may comprise a catalyst, and optionally an ionomer and / or a binder. In an embodiment, the catalyst layer may comprise a catalyst and an ionomer. In another embodiment, the catalyst layer may comprise a catalyst and a binder. In yet another embodiment, the catalyst layer may comprise a catalyst, an ionomer, and a binder. In still another embodiment, the GDE has only a single catalyst layer. In other embodiments, the GDE may comprise more than one catalyst layer.

[0184] The catalyst layer may be hydrophilic or hydrophobic, for example depending on the desired operation of the CL. In an embodiment, if the GDE comprises two CL, the firstCL is hydrophilic and the second CL is hydrophobic. In other embodiments, both CLs may be hydrophobic or hydrophilic.

[0185] The catalyst layer may have a thickness of between 1 pm and 100 pm, between 1 pm and 95 pm, between 1 pm and 90 pm, between 1 pm and 85 pm, between1 pm and 80 pm, between 1 pm and 75 pm, between 1 pm and 70 pm, between 1 pm and 65 pm, between 1 pm and 60 pm, between 1 pm and 55 pm, between 1 pm and 50 pm, between 1 pm and 45 pm, between 1 pm and 40 pm, between 1 pm and 35 pm, between1 pm and 30 pm, between 1 pm and 25 pm, between 1 pm and 20 pm, between 1 pm and 15 pm, between 1 pm and 10 pm, between 1 pm and 9 pm, between 1 pm and 8 pm, between 1 pm and 7 pm, between 1 pm and 6 pm, between 1 pm and 5 pm, between 1 pm and 4 pm, between 1 pm and 3 pm, or between 1 pm and 2 pm.

[0186] The catalyst layer may have a porosity of between 30% to 75%, between 30% to 70%, between 30% to 65%, between 30% to 60%, between 30% to 55%, between 30% to50%, between 30% to 55%, between 30% to 50%, between 30% to 45%, between 30% to40%, between 30% to 35%, between 35% to 75%, between 40% to 75%, between 45% to75%, between 50% to 75%, between 55% to 75%, between 60% to 75%, between 65% to75%, or between 70% to 75%.

[0187] The ionomencatalyst ratio may be between 1:1 to 1:20, between 1:1 to 1:19, between 1:1 to 1:18, between 1:1 to 1:17, between 1:1 to 1:16, between 1:1 to 1:15, between 1:1 to 1:14, between 1:1 to 1:13, between 1:1 to 1:12, between 1:1 to 1:11, between 1:1 to 1:10, between 1:1 to 1:9, between 1:1 to 1:8, between 1:1 to 1:7, between 1:1 to 1:6, between 1:1 to 1:5, between 1:1 to 1:4, between 1:1 to 1:3, between 1:1 to 1:2, between 1:2 to 1:20, between 1 :3 to 1 :20, between 1 :4 to 1 :20, between 1 :5 to 1 :20, between 1 :6 to 1 :20, between 1:7 to 1:20, between 1:8 to 1:20, between 1:9 to 1:20, between 1:10 to 1:20, between 1:11 to 1:20, between 1:12 to 1:20, between 1:13 to 1:20, between 1:14 to 1:20, between 1:15 to 1:20, between 1:16 to 1:20, between 1:17 to 1:20, between 1:18 to 1:20, between 1:19 to 1:20, between 1:2 to 1:19, between 1:3 to 1:18, between 1:4 to 1:17, between 1:5 to 1:16, between 1:6 to 1:15, between 1:7 to 1:14, between 1:8 to 1:13, between 1:9 to 1:12, or between 1:10 to 1:11.Catalyst

[0188] The catalyst may include (6) a metal, (7) a non-metal, or a combination thereof.

[0189] The metal may be (6a) a transition metal, (6b) a post-transition metal, (6c) a metalloid, or a combination thereof, or an alloy thereof.

[0190] The catalyst including a transition metal may include:(6a-a) scandium (Sr), (6a-g) cobalt (Co), (6a-m) molybdenum (Mo), (6a-s) hafnium (Hf),(6a-b) titanium (Ti), (6a-h) nickel (Ni), (6a-n) ruthenium (Ru), (6a-t) tungsten (W),(6a-c) vanadium (V), (6a-i) copper (Cu), (6a-o) rhodium (Rh), (6a-u) iridium (Ir),(6a-d) chromium (Cr), (6a-j) zinc (Zn), (6a-p) palladium (Pd), (6a-v) platinum (Pt),(6a-e) manganese (Mn), (6a-k) yttrium (Y), (6a-q) silver (Ag), (6a-w) gold (Au),(6a-f) iron (Fe), (6a-l) zirconium (Zr), (6a-r) cadmium (Cd), or a combination thereof, or an alloy thereof.

[0191] The catalyst including a post-transition metal may include:(6b-a) aluminum (Al), (6b-c) indium (In), (6b-e) thallium (TI), (6b-g) bismuth (Bi),(6b-b) gallium (Ga), (6b-d) tin (Sn), (6b-f) lead (Pb), or a combination thereof, or an alloy thereof.

[0192] The catalyst including a metalloid may include: (6c-a) silicon (Si), (6c-b) germanium (Ge), (6c-c) antimony (Sb), (6c-d) telelium (Te), or a combination thereof.

[0193] The catalyst including a non-metal may include (7a) carbon, (7b) a conductive polymer, or a combination thereof.

[0194] The carbon refers to a material whose main component is composed of carbon atoms. For example, the carbon may be a carbon fiber, graphite, a carbon nanomaterial, or a combination thereof. The carbon nanomaterial may include a carbon nanotube, graphene, carbon nanoplate, or fullerene. Further, the material may optionally be doped with non-metallic elements (e.g. B, N, P, O or S).

[0195] The catalyst loading on the GDL may be between 0.1 and 10 mg cm-2, between 0.1 and 9.0 mg cm'2, between 0.1 and 8.0 mg cm-2, between 0.1 and 7.0 mg cm'2, between 0.1 and 6.0 mg cm'2, between 0.1 and 5.0 mg cm-2, between 0.1 and 4.0 mg cm'2, between 0.1 and 3.9 mg cm'2, between 0.1 and 3.8 mg cm-2, between 0.1 and 3.7 mg cm'2, between 0.1 and 3.6 mg cm'2, between 0.1 and 3.5 mg cm-2, between 0.1 and 3.4 mg cm'2, between 0.1 and 3.3 mg cm'2, between 0.1 and 3.2 mg cm-2, between 0.1 and 3.1 mg cm'2, between 0.1 and 3.0 mg cm'2, between 0.1 and 2.9 mg cm'2, between 0.1 and 2.8 mg cm-2, between 0.1 and 2.7 mg cm'2, between 0.1 and 2.6 mg cm-2, between 0.1 and 2.5 mg cm'2, between 0.1 and 2.4 mg cm'2, between 0.1 and 2.3 mg cm-2, between 0.1 and 2.2 mg cm'2, between 0.1 and 2.1 mg cm'2, between 0.1 and 2.0 mg cm-2, between 0.1 and 1.9 mg cm'2, between 0.1 and 1.8 mg cm'2, between 0.1 and 1.7 mg cm-2, between 0.1 and 1.6 mg cm'2, between 0.1 and 1.5 mg cm'2, between 0.1 and 1.4 mg cm-2, between 0.1 and 1.3 mg cm'2, between 0.1 and 1.2 mg cm'2, between 0.1 and 1.1 mg cm-2, between 0.1 and 1.0 mg cm'2, between 0.1 and 0.9 mg cm'2, between 0.1 and 0.8 mg cm-2, between 0.1 and 0.7 mg cm'2, between 0.1 and 0.6 mg cm'2, between 0.1 and 0.5 mg cm-2, between 0.1 and 0.4 mg cm'2, between 0.1 and 0.3 mg cm'2, or between 0.1 and 0.2 mg cm'2.Ionomer

[0196] The ionomer includes a polymer wherein at least a portion of the repeating units of the polymer comprise ionic groups (e.g., wherein the polymer is a copolymer comprising electrically neutral units and units comprising an ionic group).

[0197] In an embodiment, the ionomer comprises an anion exchange ionomer. The anion exchange ionomer includes ionomers where the ionic groups are preferably cationic groups, which promote conduction of anions via electrostatic interaction between the anions and cationic groups.

[0198] Non-limiting examples of the anion exchange ionomer (AEI) include (8a) Fumion™ FAA-3 AEI, (8b) lonomr™ AEI (e.g. AF1 , AF2, AF3, AP1 , AP3), (8c) Sustainion® AEI (e.g. XA-9, XB-7, XC-1 , XC-2), (8d) Orion AEI (e.g. TM1 , AM, CMX), (8e) Pention™ AEI (e.g. D18, D35, D72), and (8f) PiperlON AEI.

[0199] In an embodiment, the ionomer comprises a cation exchange ionomer. The cation exchange ionomer includes ionomers where the ionic groups are preferably anionicgroups, which promote conduction of cations via electrostatic interaction between the anions and cationic groups.

[0200] Non-limiting examples of the cation exchange ionomer (CEI) include Aquivion® CEI (e.g. D72-25BS, D79-25BS, D83-24B, D98-25BS), FORBLUE™ i-SERIES CEI (e.g. IC100, IC154), Fumion™ CEI (e.g. E-600, FSLA-102, FSLA-725), lonomr™ CEI (e.g. PP1 ), and Nation™ CEI (e.g. D520CS, D521CS, D2020CS, D2021CS).

[0201] The CL may comprise between 5 wt% and 45 wt%, between 5 wt% and 40 wt%, between 5 wt% and 35 wt%, between 5 wt% and 30 wt%, between 5 wt% and25 wt%, between 5 wt% and 20 wt%, between 5 wt% and 15 wt%, between 5 wt% and10 wt%, between 10 wt% and 45 wt%, between 15 wt% and 45 wt%, between 20 wt% and45 wt%, between 25 wt% and 45 wt%, between 30 wt% and 45 wt%, between 35 wt% and45 wt%, between 40 wt% and 45 wt%, between 10 wt% and 40 wt%, between 15 wt% and35 wt%, or between 20 wt% and 30 wt% of the ionomer.Binder

[0202] In an embodiment, the CL comprises a binder. The binder may, for example, be a polymer that is hydrophilic or hydrophobic. Non-limiting examples of the binder include (9a) PTFE.

[0203] The CL may comprise no binder or, if present, between 0.01 wt% and 40 wt%, between 0.01 wt% and 35 wt%, between 0.01 wt% and 30 wt%, between 0.01 wt% and 25 wt%, between 0.01 wt% and 20 wt%, between 0.01 wt% and 15 wt%, between 0.01 wt% and 10 wt%, between 0.01 wt% and 5 wt%, between 5 wt% and 40 wt%, between 10 wt% and 40 wt%, between 15 wt% and 40 wt%, between 20 wt% and 40 wt%, between 25 wt% and 40 wt%, between 30 wt% and 40 wt%, between 35 wt% and 40 wt%, between 5 wt% and 35 wt%, between 10 wt% and 30 wt%, or between 15 wt% and 25 wt% of the binder.

[0204] Various particular embodiments of GDEs of the present disclosure include GDEs described herein as GDE-1, GDE-2, GDE-3 or GDE-4, each having components as defined in the following rows, wherein each entry is a group number as defined above:

[0205] Various additional embodiments of GDEs of the present disclosure will be appreciated by the skilled person. For example, in respect of GDE-1 type GDEs as described herein, any of Embodiments 1-768 for these GDEs may further comprise an AEM as described herein, for example as shown in FIGs. 10(e)-(h). Further, in respect of GDE-1 , GDE-2 and GDE-4 type GDEs as described herein, any of Embodiments 1-768 for these GDEs may further comprise an MPL as described herein, for example as shown in FIGs. 10(b), (d), (f) and (h), FIGs. 1 1 (b) and (d), and FIGs. 13(b) and 13(d) . Further, in respect of GDE-1 , GDE-2, GDE-3, and GDE-4 type GDEs as described herein, any of Embodiments 1-768 for these GDEs may further comprise a mesh as described herein, for example as shown in FIGs. 10(c)-(h), 11 (c)-(d), 12(b) and 13(c) and 13(d).

[0206] As described herein, the GDE-4 comprises a 1stGDL and a 2ndGDL, each of which may be the same or different. With respect to GDE-4, in any of Embodiments 1-768 at least one of the 1stGDL and the 2ndGDL is the GDL as defined for the respective embodiment of Embodiments 1-768. In an embodiment, the 1stGDL and the 2ndGDL are the same, and both of the GDLs in GDE-4 are as defined for the respective embodiment of Embodiments 1-768. In another embodiment, the 1stGDL and the 2ndGDL are different and only one of the GDLs is as defined for the respective embodiment of Embodiments 1-768. In an embodiment where the GDLs in the GDE-4 are different, it is the 1stGDL that is as defined for the respective embodiment of Embodiments 1-768. In an embodiment where the GDLs in the GDE-4 are different, it is the 2ndGDL that is as defined for the respective embodiment of Embodiments 1-768.

[0207] In an embodiment, the GDE-1, GDE-2 or GDE-4 of the present disclosure may comprise an AEM. Embodiments of AEMs are described elsewhere herein and that disclosure is equally applicable to AEMs that are a component of the GDE.

[0208] In an embodiment, the AEM of the GDE comprises a polymer having at least one positively charged cationic group bound to at least a portion of a polymeric backbone. In an embodiment, the polymer comprises polyalkylene, a polyfluorene, a poly(arylene ether), a polysulfone, a poly(arylene ether sulfone), a polyetherketone, a polyetherimide, a poly(ether oxadiazole), a poly(phenylene oxide), a poly(vinyl benzyl), a polyphenylene, a perfluoro, a polybenzimidazole, a polystyrene, or a polyphosphazene. In an embodiment, the positively charged cationic group is a primary, secondary, tertiary or quaternary ammonium, a heterocyclic cation, a guanidinium, a phosphonium, a sulfonium, or a metal cation.

[0209] In an embodiment, the AEM of the GDE is a Fumasep™, a Neosepta™, an Orion™, a Xergy Xion Pention™, a PiperlON™, a Ralex™, a Sustanion™, or an lonomr™ anion exchange membrane.

[0210] As mentioned, in an embodiment the electrolysis cell is one that comprises a GDE. The GDE may be any of those as described herein. In the electrolysis cells herein, one or more ion exchange membranes are stacked in an order specific to the components of the salt solution being processed as well as the desired outputs. The membranes are designed to allow specific charged ionic species permeate through. Cation exchange membranes transfer cationic species while anion exchange membrane only allow anions transport through the membrane structure. The movement of ions is enabled by applying an external voltage using a cathode and anode electrode. Under applied voltage, anions travel toward the positively charged anode while cations travel towards the negatively charged cathode. Through careful placement of membranes, desired chemicals such acids, bases, and salts can be produced.

[0211] Various different types of multi-compartment electrolysis cells comprising GDEs may be used, such as those described herein.5-compartment membrane electrolysis cell

[0212] In an embodiment, the electrolysis cell is a 5-compartment membrane electrolysis cell.

[0213] In an embodiment, the 5-compartment membrane electrolysis cell comprises an anode compartment; a cathode compartment; a base build-up compartment, a saltdepletion compartment, and an acid build-up compartment. Each compartment may be separated by, for example, an AEM, a CEM or a BPM, such as described herein without limitation.

[0214] In an embodiment, the 5-compartment membrane electrolysis cell comprises: an anode compartment (AC) and a cathode compartment (CC); and each of a base build-up compartment (BBC), a salt depletion compartment (SDC) and an acid build-up compartment (ABC) interposed between the CC and the AC. In an embodiment, the BBC is interposed between the CC and the SDC, the SDC is interposed between the BBC and the ABC, and the ABC is interposed between the SDC and the AC (e.g. AC-ABC-SDC-BBC-CC). As will be appreciated, other arrangements are possible and are encompassed herein.

[0215] In an embodiment, the 5-compartment membrane electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; an anion exchange membrane interposed between the salt depletion compartment and the acid buildup compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the acid build-up compartment; and a second bipolar exchange membrane interposed between the anode compartment and the acid build-up compartment and being configuredto dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane.

[0216] As used herein, by “positioned to extend within the interior” it is intended to refer to a configuration where all or a portion of the anode or cathode extends into the interior of the membrane electrolysis cell to thereby position all or a portion of the anode or cathode in the anode compartment or the cathode compartment, respectively.

[0217] In operation, a salt solution is received into the salt depletion compartment; positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the positive salt ions and the OH- ions in the base-build-up compartment together form a base / alkaline compound.

[0218] In an embodiment of the 5-compartment membrane electrolysis cell herein, the cathode comprises a gas diffusion electrode, such as for example and without limitation, any gas diffusion electrode described herein. In an embodiment, the gas diffusion electrode comprises a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions.

[0219] In an embodiment, the 5-compartment membrane electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the membrane electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layerand the catalyst layer being configured to transport negative ions; a first anion exchange membrane, the first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membrane into the base build-up compartment; a first cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the acid build-up compartment; and a second cation exchange membrane interposed between the acid build-up compartment and the anode compartment, the second cation exchange membrane being configured to exchange ions received from the anode compartment to an opposed surface of the second cation exchange membrane into the acid build-up compartment.

[0220] In operation, a salt solution is received into the salt depletion compartment; positive salt ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; a gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base build-up compartment; and the OH- ions and the positive salt ions in the base build-up compartment together form a base / alkaline compound.

[0221] In an embodiment, the 5-compartment membrane electrolysis cell further comprises an inlet through which a salt solution is received into an interior of the electrolysis cell (e.g. into the salt depletion compartment). In an embodiment, the 5-compartment membrane electrolysis cell further comprises at least one outlet through which a product is removed from an interior of the electrolysis cell. In an embodiment of the 5-compartment membrane electrolysis cell comprising a gas diffusion electrode, there may further be a gas inlet (e.g. positioned in the cathode compartment) through which a gas comprising O2 is introduced into contact with the gas diffusion electrode.

[0222] In an embodiment, the membrane electrolysis cell comprises five compartments as depicted in FIG. 14. The membrane electrolysis cell comprises a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between a cathode compartment and an anode compartment. The base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment.

[0223] An anode is housed in the anode compartment.

[0224] A cathode comprising a gas diffusion electrode (GDE) is housed in the cathode compartment, wherein:• When the GDE is GDE-1 described herein, the CL of the GDEs shown in FIGs. 10(a)-(d) is in direct contact with the 1stAEM shown in FIG. 14. Otherwise, the AEM of the GDEs shown in FIGs. 10(e)-(h) is the 1stAEM shown in FIG. 14. The 1stAEM defines a boundary between the cathode compartment and the base build-up compartment. The cathode compartment is in fluid communication with the base build-up compartment via the 1stAEM. The base build-up compartment is defined by the 1stAEM and a 1stCEM.• When the GDE is GDE-2 described herein, the CCM of the GDEs shown in FIGs. 11(a)-(d) is in place of the 1stAEM shown in FIG. 14. The CCM defines a boundary between the cathode compartment and the base build-up compartment. The cathode compartment is in fluid communication with the base build-up compartment via the CCM. The base build-up compartment is defined by the CCM and the 1stCEM.• When the GDE is GDE-3 described herein, the 1stAEM shown in FIG. 14 is omitted resulting in the cathode compartment and the base build-up compartment becoming a single compartment. Therefore, use of GDE-3 without the 1stAEM effectively renders the cell to a 4-compartment membrane electrolysis cell.• When the GDE is GDE-4 described herein, the AEM of the GDEs shown in FIGs. 13(a)-(d) is the 1stAEM shown in FIG. 14. The 1stAEM defines a boundary between the cathode compartment and the base build-up compartment. The cathode compartment is in fluid communication with the base build-up compartment via the 1stAEM. The base build-up compartment is defined by the 1stAEM and a 1stGEM.

[0225] The 1stGEM defines a boundary between the base build-up compartment and the salt depletion compartment. The base build-up compartment is in fluid communication with the salt depletion compartment via the 1stGEM. The salt depletion compartment is defined by the 1stGEM and a 2ndAEM. The 2ndAEM defines a boundary between the salt depletion compartment and the acid build-up compartment. The salt depletion compartment is in fluid communication with the acid build-up compartment via the 2ndAEM. The acid build-up compartment is defined by the 2ndAEM and a 2ndGEM. The 2ndGEM defines a boundary between the acid build-up compartment and the anode compartment. The acid build-up compartment is in fluid communication with the anode compartment via the 2ndGEM.

[0226] The 1stand 2ndAEMs are as described herein and may be the same or different. The 1stand 2ndCEMs are as described herein and may be the same or different.

[0227] In operation, a salt solution comprising positive ions and negative ions is fed or received into the salt depletion compartment. A gas comprising oxygen is fed or received into the GDE in the cathode compartment. When a voltage is applied across the anode and cathode, the positive ions from the salt solution migrate towards the negatively charged cathode compartment through the 1stGEM and remain in the base build-up compartment, since they cannot pass through the 1stAEM (GDE-1 and GDE-4), the CCM (GDE-2), or the catalyst layer (GDE-3). Gas comprising O2 is reduced at the GDE / cathode to form OFT. The OH- anions produced at the GDE build up in the base build-up compartment since they will migrate away from the negatively charged cathode towards the positively charged anode through the 1stAEM (GDE-1 and GDE-4), the CCM (GDE-2), or the catalyst layer (GDE-3). Like the positive ions, the OH- ions remain in the base build-up compartment because they cannot pass through the 1stGEM. Therefore, a base / alkaline compound is formed in the base build-up compartment. As shown in FIG. 14, the negative ions from the salt solution migrate towards the positively charged anode compartment through the 2ndAEM and remain in the acid build-up compartment, since they cannot pass through the 2ndGEM. The anodic reactionresults in the formation of protons which are then transported through the 2ndCEM into the acid build-up compartment. The protons combine with the negative ions to form an acid.

[0228] If the salt solution comprises LiCI, IJ2SO4, U3PO4, UNO3, or Lil, then LiOH will be produced in the base build-up compartment and HCI, H2SO4, H3PO4, HNO3, HI, respectively, will be produced simultaneously in the acid build-up compartment. Likewise, if the salt solution comprises NaCI, Na2SC>4, NasPCL, NaNOs, or Nal, then NaOH will be produced in the base build-up compartment and HCI, H2SO4, H3PO4, HNO3, HI, respectively, will be produced simultaneously in the acid build-up compartment. And, if the salt solution comprises KCI, K2SO4, K3PO4, KNO3, or KI, then KOH will be produced in the base build-up compartment and HCI, H2SO4, H3PO4, HNO3, HI, respectively, will be produced simultaneously in the acid build-up compartment.4-compartment membrane electrolysis cell

[0229] In an embodiment, the electrolysis cell is a 4-compartment membrane electrolysis cell.

[0230] In an embodiment, the 4-compartment membrane electrolysis cell comprises an anode compartment; a cathode compartment; and two additional compartments selected from any combination of a base build-up compartment, a salt depletion compartment, and an acid build-up compartment. In an embodiment, the 4-compartment membrane electrolysis cell comprises an anode compartment; a cathode compartment; a base build-up compartment, and a salt depletion compartment. Each compartment may be separated by, for example, an AEM, a CEM or a BPM, such as described herein without limitation.

[0231] In an embodiment, the 4-compartment membrane electrolysis cell comprises: an anode compartment (AC) and a cathode compartment (CC); and each of a base build-up compartment (BBC) and a salt depletion compartment (SDC) interposed between the CC and the AC. In an embodiment, the BBC is interposed between the CC and the SDC, and the SDC is interposed between the BBC and the AC (e.g. AC-SDC-BBC-CC).

[0232] In an embodiment, the 4-compartment membrane electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathodecompartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; and a second bipolar exchange membrane interposed between the anode compartment and the salt depletion compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane.

[0233] In operation, a salt solution is received into the salt depletion compartment; positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the positive salt ions and the OH- ions in the base-build-up compartment together form a base / alkaline compound.

[0234] In an embodiment of the 4-compartment membrane electrolysis cell herein, the cathode comprises a gas diffusion electrode, such as for example and without limitation, any gas diffusion electrode described herein. In an embodiment, the gas diffusion electrode comprises a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions.

[0235] In an embodiment, the 4-compartment membrane electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, and the salt depletion compartment isinterposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the membrane electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membrane into the base build-up compartment; a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; and a second anion exchange membrane interposed between the salt depletion compartment and the anode compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the anode compartment.

[0236] In operation, a salt solution is received into the salt depletion compartment; positive salt ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; a gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base buildup compartment; and the OH- ions and the positive ions in the base build-up compartment together form a base / alkaline compound.

[0237] In an embodiment, the 4-compartment membrane electrolysis cell further comprises an inlet through which a salt solution is received into an interior of the electrolysis cell (e.g. into the salt depletion compartment). In an embodiment, the 4-compartment membrane electrolysis cell further comprises at least one outlet through which a product is removed from an interior of the electrolysis cell. In an embodiment of the 4-compartment membrane electrolysis cell comprising a gas diffusion electrode, there may further be a gas inlet (e.g. positioned in the cathode compartment) through which a gas comprising O2 is introduced into contact with the gas diffusion electrode.

[0238] In an embodiment, the membrane electrolysis cell comprises four compartments as depicted in FIG. 15. The membrane electrolysis cell comprises a base build-up compartment and a salt depletion compartment interposed between a cathode compartment and an anode compartment. The base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment.

[0239] An anode is housed in the anode compartment.

[0240] A cathode comprising a gas diffusion electrode (GDE) is housed in the cathode compartment, wherein:• When the GDE is GDE-1 described herein, the CL of the GDEs shown in FIGs. 10(a)-(d) is in direct contact with a 1stAEM shown in FIG. 15. Otherwise, the AEM of the GDEs shown in FIGs. 10(e)-(h) is the 1stAEM shown in FIG. 15. The 1stAEM defines a boundary between the cathode compartment and the base build-up compartment. The cathode compartment is in fluid communication with the base build-up compartment via the 1stAEM. The base build-up compartment is defined by the 1stAEM and a CEM.• When the GDE is GDE-2 described herein, the CCM of the GDEs shown in FIGs. 11 (a)-(d) is in place of the 1stAEM shown in FIG. 15. The CCM defines a boundary between the cathode compartment and the base buildup compartment. The cathode compartment is in fluid communication with the base build-up compartment via the CCM. The base build-up compartment is defined by the CCM and the CEM.• When the GDE is GDE-3 described herein, the 1stAEM shown in FIG. 15 is omitted resulting in the cathode compartment and the base build-up compartment becoming a single compartment. Therefore, use of GDE-3 without the 1stAEM effectively renders the cell to a 3-compartment membrane electrolysis cell.• When the GDE is GDE-4 described herein, the AEM of the GDEs shown in FIGs. 13(a)-(d) is the 1stAEM shown in FIG. 15. The 1stAEM defines a boundary between the cathode compartment and the base build-up compartment. The cathode compartment is in fluid communication with the base build-up compartment via the 1stAEM. The base build-up compartment is defined by the 1stAEM and a GEM.

[0241] The GEM defines a boundary between the base build-up compartment and the salt depletion compartment. The base build-up compartment is in fluid communication with the salt depletion compartment via the GEM. The salt depletion compartment is defined by the GEM and a 2ndAEM. The 2ndAEM defines a boundary between the salt depletion compartment and the anode compartment. The salt depletion compartment is in fluid communication with the anode compartment via the 2ndAEM.

[0242] The 1stand 2ndAEMs are as described herein and may be the same or different. The GEM is as described herein.

[0243] In operation, a salt solution comprising positive ions and negative ions is fed or received into the salt depletion compartment. A gas comprising oxygen is fed or received into the GDE in the cathode compartment. When a voltage is applied across the anode and cathode, the positive ions from the salt solution migrate towards the negatively charged cathode compartment through the GEM and remain in the base build-up compartment, since they cannot pass through the 1stAEM (GDE-1 and GDE-4), the CCM (GDE-2), or the catalyst layer (GDE-3). Gas comprising O2 is reduced at the GDE / cathode to form OFT. The OFT anions produced at the GDE build up in the base build-up compartment since they will migrate away from the negatively charged cathode towards the positively charged anode through the 1stAEM (GDE-1 and GDE-4), the CCM (GDE-2), or the catalyst layer (GDE-3). Like the positive ions, the OH- ions remain in the base build-up compartment because they cannot pass through the GEM. Therefore, a base / alkaline compound is formed in the base build-up compartment. As shown in FIG. 15, the negative ions from the salt solution migrate towards the positively charged anode compartment through the 2ndAEM into the anode compartment.

[0244] If the salt solution comprises (a) LiCI, LiBr, or Lil, (b) NaCI, NaBr, or Nal, or (c) KCI, KBr, or KI, then (a) LiOH, (b) NaOH, or (c) KOH, respectively, will be produced in the base build-up compartment. Simultaneously, HCI, HBr or HI will be produced in the anodecompartment (dependent of the input salt solution) with the possibility of production of CI2, Br2 or I2, respectively.

[0245] If the salt solution comprises IJ2SO4, IJ3PO4, or IJNO3, then LiOH will be produced in the base build-up compartment and H2SO4, H3PO4, or HNO3, respectively, will be produced simultaneously in the anode compartment. Likewise, if the salt solution comprises Na2SC>4, NasPO4, or NaNOs, then NaOH will be produced in the base build-up compartment and H2SO4, H3PO4, or HNO3, respectively, will be produced simultaneously in the anode compartment. And, if the salt solution comprises K2SO4, K3PO4, or KNO3, then KOH will be produced in the base build-up compartment and H2SO4, H3PO4, or HNO3, respectively, will be produced simultaneously in the anode compartment.3-compartment membrane electrolysis cell

[0246] In an embodiment, the electrolysis cell is a 3-compartment membrane electrolysis cell.

[0247] In an embodiment, the 3-compartment membrane electrolysis cell comprises an anode compartment; a cathode compartment; and one additional compartment selected from any of a base build-up compartment, a salt depletion compartment, and an acid build-up compartment. In an embodiment, the 3-compartment membrane electrolysis cell comprises an anode compartment; a cathode compartment; and a base build-up compartment. In an embodiment, the 3-compartment membrane electrolysis cell comprises an anode compartment; a cathode compartment; and a salt depletion compartment. Each compartment may be separated by, for example, an AEM, a CEM or a BPM, such as described herein without limitation.

[0248] In an embodiment, the 3-compartment membrane electrolysis cell comprises: an anode compartment; a cathode compartment; and a salt depletion compartment interposed between the cathode compartment and the anode compartment.

[0249] In an embodiment, the 3-compartment membrane electrolysis cell comprises: an anode compartment; a cathode compartment; and a base build-up compartment interposed between the cathode compartment and the anode compartment.

[0250] In an embodiment, the 3-compartment membrane electrolysis cell comprises: an anode compartment; a cathode compartment; a salt depletion compartment interposedbetween the cathode compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; an anion exchange membrane interposed between the anode compartment and the salt depletion compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the anode compartment; and a cation exchange membrane interposed between the salt depletion compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the cathode compartment.

[0251] In operation, a salt solution is received into the salt depletion compartment; positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; water is reduced at the cathode to form OH-; and the positive salt ions and the OH- ions in the cathode compartment together form a base / alkaline compound.

[0252] In an embodiment of the 3-compartment membrane electrolysis cell herein, the cathode comprises a gas diffusion electrode, such as for example and without limitation, any gas diffusion electrode described herein. In an embodiment, the gas diffusion electrode comprises a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions.

[0253] In an embodiment, the 3-compartment membrane electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment interposed between the cathode compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; an anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode andbeing configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the anion ion exchange membrane into the base build-up compartment; and a cation exchange membrane interposed between the anode compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane into the base build-up compartment.

[0254] In operation, a salt solution is received into the anode compartment; positive salt ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; a gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the anion exchange membrane to the opposed surface of the anion exchange membrane into the base build-up compartment; and the OH- ions and the positive salt ions in the base build-up compartment together form a base / alkaline compound.

[0255] In an embodiment, the 3-compartment membrane electrolysis cell further comprises an inlet through which a salt solution is received into an interior of the electrolysis cell (e.g. into the salt depletion compartment, into the anode compartment, etc.). In an embodiment, the 3-compartment membrane electrolysis cell further comprises at least one outlet through which a product is removed from an interior of the electrolysis cell. In an embodiment of the 3-compartment membrane electrolysis cell comprising a gas diffusion electrode, there may further be a gas inlet (e.g. positioned in the cathode compartment) through which a gas comprising O2 is introduced into contact with the gas diffusion electrode.

[0256] In an embodiment, the membrane electrolysis cell comprises three compartments as depicted in FIG. 16. The membrane electrolysis cell comprises a base build-up compartment interposed between a cathode compartment and an anode compartment.

[0257] An anode is housed in the anode compartment.

[0258] A cathode comprising a gas diffusion electrode (GDE) is housed in the cathode compartment, wherein:• When the GDE is GDE-1 described herein, the CL of the GDEs shown in FIGs. 10(a)-(d) is in direct contact with an AEM shown in FIG. 16.Otherwise, the AEM of the GDEs shown in FIGs. 10(e)-(h) is the AEM shown in FIG. 16. The AEM defines a boundary between the cathode compartment and the base build-up compartment. The cathode compartment is in fluid communication with the base build-up compartment via the AEM. The base build-up compartment is defined by the AEM and a GEM.• When the GDE is GDE-2 described herein, the COM of the GDEs shown in FIGs. 11 (a)-(d) is in place of the AEM shown in FIG. 16. The COM defines a boundary between the cathode compartment and the base buildup compartment. The cathode compartment is in fluid communication with the base build-up compartment via the COM. The base build-up compartment is defined by the COM and the GEM.• When the GDE is GDE-3 described herein, the AEM shown in FIG. 16 is omitted resulting in the cathode compartment and the base build-up compartment becoming a single compartment. Therefore, use of GDE-3 without the AEM effectively renders the cell to a 2-compartment membrane electrolysis cell.• When the GDE is GDE-4 described herein, the AEM of the GDEs shown in FIGs. 13(a)-(d) is the AEM shown in FIG. 16. The AEM defines a boundary between the cathode compartment and the base build-up compartment. The cathode compartment is in fluid communication with the base build-up compartment via the AEM. The base build-up compartment is defined by the AEM and a GEM.

[0259] The GEM defines a boundary between the base build-up compartment and the anode compartment. The base build-up compartment is in fluid communication with the anode compartment via the GEM.

[0260] The GEM and AEM are as described herein.

[0261] In operation, a salt solution comprising positive ions and negative ions is fed or received into the anode compartment. A gas comprising oxygen is fed or received into the GDE in the cathode compartment. When a voltage is applied across the anode and cathode,the positive ions from the salt solution migrate towards the negatively charged cathode compartment through the CEM and remain in the base build-up compartment, since they cannot pass through the AEM (GDE-1 and GDE-4), the CCM (GDE-2), or the catalyst layer (GDE-3). Gas comprising O2 is reduced at the GDE / cathode to form OH-. The OH- anions produced at the GDE build up in the base build-up compartment since they will migrate away from the negatively charged cathode towards the positively charged anode through the AEM (GDE-1 and GDE-4), the CCM (GDE-2), or the catalyst layer (GDE-3). Like the positive ions, the OH- ions remain in the base build-up compartment because they cannot pass through the CEM. Therefore, a base / alkaline compound is formed in the base build-up compartment.

[0262] If the salt solution comprises (a) LiCI, LiBr, or Lil, (b) NaCI, NaBr, or Nal, or (c) KCI, KBr, or KI, then (a) LiOH, (b) NaOH, or (c) KOH, respectively, will be produced in the base build-up compartment. Simultaneously, HCI, HBr or HI will be produced in the anode compartment (dependent of the input salt solution) with the possibility of production of CI2, Br2 or I2, respectively.

[0263] If the salt solution comprises Li2SO4, Li3PO4, or LiNO3, then LiOH will be produced in the base build-up compartment and H2SO4, H3PO4, or HNO3, respectively, will be produced simultaneously in the anode compartment. Likewise, if the salt solution comprises Na2SO4, Na3PO4, or NaNO3, then NaOH will be produced in the base build-up compartment and H2SO4, H3PO4, or HNO3, respectively, will be produced simultaneously in the anode compartment. And, if the salt solution comprises K2SO4, K3PO4, or KNO3, then KOH will be produced in the base build-up compartment and H2SO4, H3PO4, or HNO3, respectively, will be produced simultaneously in the anode compartment.2-compartment membrane electrolysis cell

[0264] In an embodiment, the electrolysis cell is a 2-compartment membrane electrolysis cell.

[0265] In an embodiment, the 2-compartment membrane electrolysis cell comprises an anode compartment; a cathode compartment; and an AEM, a CEM or a BPM interposed between the anode compartment and the cathode compartment.

[0266] In an embodiment, the 2-comparment membrane electrolysis cell comprises an anode compartment; a cathode compartment; an anode positioned to extend within theinterior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; and a cation exchange membrane interposed between the anode compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions from the anode compartment to an opposed surface of the cation exchange membrane into the cathode compartment.

[0267] In operation, a salt solution is received into the anode compartment and positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; water is reduced at the cathode to form OH-; and the positive salt ions and the OH- ions in the cathode compartment together form a base / alkaline compound.

[0268] In an embodiment of the 2-compartment membrane electrolysis cell herein, the cathode comprises a gas diffusion electrode, such as for example and without limitation, any gas diffusion electrode described herein. In an embodiment, the gas diffusion electrode comprises a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions.

[0269] In an embodiment, the 2-comparment membrane electrolysis cell comprises an anode compartment; a cathode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; and a cation exchange membrane interposed between the anode compartment and the catalyst layer of the gas diffusion electrode, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane.

[0270] In operation, a salt solution is received into the anode compartment; positive salt ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; a gas comprising O2 is reduced at thecathode to form OH-; and the OH- ions and the positive salt ions in the cathode compartment together form a base / alkaline compound.

[0271] In an embodiment, the 2-compartment membrane electrolysis cell further comprises an inlet through which a salt solution is received into an interior of the electrolysis cell (e.g. into the anode compartment). In an embodiment, the 2-compartment membrane electrolysis cell further comprises at least one outlet through which a product is removed from an interior of the electrolysis cell. In an embodiment of the 2-compartment membrane electrolysis cell comprising a gas diffusion electrode, there may further be a gas inlet through which a gas comprising 02 is introduced into contact with the gas diffusion electrode.

[0272] In an embodiment, the membrane electrolysis cell comprises two compartments as depicted in FIG. 17. The membrane electrolysis cell comprises a cathode compartment and an anode compartment. The cathode and anode compartments are in fluid communication via a GEM. The GEM is as described herein.

[0273] An anode is housed in the anode compartment.

[0274] A cathode comprising a GDE as shown in FIGs. 10(a)-(d) is housed in the cathode compartment. In this embodiment, the cathode compartment also acts as a base build-up compartment in the region between the GEM and the CL of the GDE.

[0275] In operation, a salt solution comprising positive ions and negative ions is fed or received into the anode compartment. A gas comprising oxygen is fed to the GDE in the cathode compartment. When a voltage is applied across the anode and cathode, the positive ions migrate towards the negatively charged cathode compartment through the GEM. The OH- anions produced at the GDE remain in the cathode compartment because they cannot pass through the GEM. Therefore, a base / alkaline compound is formed in the cathode compartment.

[0276] If the salt solution comprises (a) LiCI, LiBr, or Lil, (b) NaCI, NaBr, or Nal, or (c) KOI, KBr, or KI, then (a) LiOH, (b) NaOH, or (c) KOH, respectively, will be produced in the cathode compartment. Simultaneously, HOI, HBr or HI will be produced in the anode compartment (dependent of the input salt solution) with the possibility of production of CI2, Br2 or I2, respectively.

[0277] If the salt solution comprises IJ2SO4, IJ3PO4, or IJNO3, then LiOH will be produced in the cathode compartment and H2SO4, H3PO4, or HNO3, respectively, will be produced simultaneously in the anode compartment. Likewise, if the salt solution comprises Na2SC>4, NasPO4, or NaNOs, then NaOH will be produced in the cathode compartment and H2SO4, H3PO4, or HNO3, respectively, will be produced simultaneously in the anode compartment. And, if the salt solution comprises K2SO4, K3PO4, or KNO3, then KOH will be produced in the cathode compartment and H2SO4, H3PO4, or HNO3, respectively, will be produced simultaneously in the anode compartment.Anion Exchange Membranes (AEM)

[0278] An AEM refers to a membrane permeable to anions. The AEM comprises a polymer having multiple positively charged cationic groups bound to at least a portion of a polymeric backbone. The cationic functional groups may be bound via an extended side chain or directly onto the backbone.

[0279] Non-limiting examples of a polymer backbone of the anion exchange membrane include a polyalkylene such as a polyethylene (PE); a polyfluorene (PFN), a poly(arylene ether) (PAE); a polysulfone, poly(arylene ether sulfone) (PAES), a polyetherketone (PEK), a polyetherimide (PEI), a poly(ether oxadiazole), a poly(phenylene oxide) (PPO); a poly(vinyl benzyl) (PVB); a polyphenylene (PPN); a perfluoro (PF); a polybenzimidazole (PBI); a polystyrene (PS); or a polyphosphazene.

[0280] Non-limiting examples of the cationic functional group include a primary, secondary, tertiary or quaternary ammonium; a heterocyclic cation such as an imidazolium or a pyridinium; a guanidinium; a phosphonium; a sulfonium; and a metal cation.

[0281] Non-limiting examples of the anion exchange membrane include:(10a) Fumasep™ FAA AEMs (e.g. FAA, FAA-3-20, FAA-3-25, FAA-3-30, FAA-3-50, FAA-3-PE-30, FAA-3-PK-75, FAA-3-PK-130),(10b) Fumasep™ FAB AEMs (e.g. FAB-PK-75, FAB-PK-130),(10c) Fumasep™ FAD AEMs (e.g. FAD-55, FAD-PET-75),(10d) Fumasep™ FAM AEMs (e.g. FAM),(10e) Fumasep™ FAAM AEMs (e.g. FAAM-10, FAAM-15, FAAM-20, FAAM-40),(1 Of) Fumasep™ FAP AEMs (e.g. FAP-330, FAP-450, FAP-330-PE, FAP-330-PE, FAP-420-PE),(10g) Fumasep™ FAPQ AEMs (e.g. FAPQ-330, FAPQ-375-PP),(1 Oh) Fumasep™ FAS AEMs (e.g. FAS-50, FAS-30, FAS-PET-75, FAS-PE-130),(10i) Neosepta™ AEMs (e.g. ACN, ACS, AFN, AFX, AHA, AMX, ASE, AXP-D),(10j) ORION™ AEMs (e.g. TM1),(10k) Xergy Xion™ Pention™ AEMs (e.g. Pention-AEM-18-05, Pention-AEM-18-10, Pention-AEM-18-20, Pention-AEM-18-30, Pention-AEM-35-05, Pention-AEM- 35-10, Pention-AEM-35-20, Pention-AEM-35-30, Pention-AEM-72-05, Pention-AEM-72-10, Pention-AEM-72-20, Pention-AEM-72-30),(101) PiperlON™ AEMs (e.g. PiperlON Anion Exchange Membrane - 15 microns, PiperlON Anion Exchange Membrane - 20 microns, PiperlON Anion Exchange Membrane - 40 microns, PiperlON Anion Exchange Membrane - 60 microns, PiperlON Anion Exchange Membrane - 80 microns),(10m) RALEX™ AEMs (e.g. AMHPES, AMHPP),(10n) SELEMION™ AEMs (e.g. AAV, AAVN, AHO, AMT, AMV, AMVN, ASV, ASVN, DSV, DSVN),(10o) Sustainion® AEMs (e.g. B22-50, E28-50, E30-50, X37-50, X37-60, X37-FA, X37-T, X37-TZ), and(10p) lonomr AEMs (e.g. Aemion).Cation Exchange Membranes (CEM)

[0282] A CEM refers to a membrane permeable to cations. In an embodiment, the CEM may be a monovalent cation selective membrane. In another embodiment, the CEM may be a lithium selective membrane.

[0283] The CEM may comprise a polymer having multiple negatively charged anionic groups bound to at least a portion of a polymeric backbone. The anionic functional groups may be bound via an extended side chain or directly onto the backbone.

[0284] Non-limiting examples of a polymer backbone of the cation exchange membrane include a polyalkylene such as a polyethylene (PE) or a polypropylene; a polyfluorene (PFN), a poly(arylene ether) (PAE); a polysulfone, poly(arylene ether sulfone) (PAES), a polyetherketone (PEK), a polyetherimide (PEI), a poly(ether oxadiazole), a poly(phenylene oxide) (PPO); a poly(vinyl benzyl) (PVB); a polyphenylene (PPN); a perfluoro (PF); a polybenzimidazole (PBI); a polystyrene (PS); or a polyphosphazene.

[0285] Non-limiting examples of the anionic functional group include a sulfonate such as a perfluorosulfonate; a carboxylate; a phosphonate; and a phenolate anion.

[0286] Non-limiting examples of the cation exchange membrane include:(l la) Aquivion® CEMs (e.g. E87-05S, E98-05S, E98-09S, E98-15S),(l lb) Fumasep™ CEMs (e.g. F-930-RFD, F-1075-PK, F-1850, F-10120, F-10120- PK, F-10150-PF, F-10270-PTFE-e, FS-720, FS-950, FS-990-PK, FS-9100- PK, FKB, FKB-PK-130, FKD-PK-75, FKE-50, FKL-PK-130, FKM, FKS-30, FKS-50, FKS-PET-75, FKS-PET-130),(l lc) Fumapem™ CEMs (e.g. F-14100, F-930, F-930-RFS, FS-715-RFS, FS-930, FS-930-RFS, F-950),(l ld) Nation™ CEMs (e.g. N115, N117, N324, N417, N424, N438, N551 , N1110),(l le) Neosepta™ CEMs (e.g. CMB, CMX, CSE, CXP-S),(l lf) SELEMION™ CEMs (e.g. CMD, CMF, CMTE, CMV, CMVN, CSC), and(l lg) Exergy Xion™ CEMS (e.g. PEM-Nafion-1000-05, PEM-Nafion-1000-10, PEM- Nafion-1000-20, PEM-Nafion-1000-30, PEM-Nafion-1000-50, PEM-Nafion- 1100-05, PEM-Nafion-1100-10, PEM-Nafion-1100-20, PEM-Nafion-1100-30, PEM-Nafion-1100-50, PEM-Aquivion-720-05, PEM-Aquivion-720-10, PEM- Aquivion-720-20, PEM-Aquivion-720-30, PEM-Aquivion-720-50, PEM-Aquivion-830-05, PEM-Aquivion-830-10, PEM-Aquivion-830-20, PEM- Aquivion-830-30, and PEM-Aquivion-830-50),(11 h) lonomr™ OEMs (e.g. Permion).

[0287] Various particular embodiments of the electrolysis cells of the present disclosure include membrane electrolysis cells (MEC), each as defined in the following rows, wherein each entry is a group number as defined above:2-compartment membrane electrolysis cell3-compartment membrane electrolysis cell-compartment membrane electrolysis cell-compartment membrane electrolysis cell

[0288] The flow rate of the salt solution in any of the electrolysis cells described herein may be between 0.5 and 5 Litres / min, between 0.5 and 4.8 Litres / min, between 0.5 and 4.6 Litres / min, between 0.5 and 4.4 Litres / min, between 0.5 and 4.2 Litres / min, between 0.5 and 4.0 Litres / min, between 0.5 and 3.8 Litres / min, between 0.5 and3.6 Litres / min, between 0.5 and 3.4 Litres / min, between 0.5 and 3.2 Litres / min, between 0.5 and 3.0 Litres / min, between 0.5 and 2.8 Litres / min, between 0.5 and 2.6 Litres / min, between 0.5 and 2.4 Litres / min, between 0.5 and 2.2 Litres / min, between 0.5 and 2.0 Litres / min, between 0.5 and 1.8 Litres / min, between 0.5 and 1.6 Litres / min, between 0.5 and 1.4 Litres / min, between 0.5 and 1.2 Litres / min, between 0.5 and 1.0 Litres / min, between 1.0 and 3.0 Litres / min, between 1.2 and 2.8 Litres / min, between 1.4 and2.6 Litres / min, between 1.6 and 2.4 Litres / min, or between 1.8 and 2.2 Litres / min.

[0289] The flow rate of the gas comprising oxygen in the electrolysis cells described herein may be between 5 and 25 Litres / min, between 5 and 23 Litres / min, between 5 and 21 Litres / min, between 5 and 19 Litres / min, between 5 and 17 Litres / min, between 5 and 15 Litres / min, between 5 and 13 Litres / min, between 5 and 11 Litres / min, between 5 and 9 Litres / min, between 5 and 7 Litres / min, between 7 and 25 Litres / min, between 9 and 25 Litres / min, between 11 and 25 Litres / min, between 13 and 25 Litres / min, between 15 and 25 Litres / min, between 17 and 25 Litres / min, between 19 and 25 Litres / min, between 21 and 25 Litres / min, between 23 and 25 Litres / min, between 7 and 23 Litres / min, between 9 and 21 Litres / min, between 11 and 19 Litres / min, or between 13 and 17 Litres / min.

[0290] The temperature of the salt solution in the electrolysis cells described herein may be between 40 and 70°C, between 40 and 65°C, between 40 and 60°C, between 40 and 55°C, between 40 and 50°C, between 40 and 45°C, between 45 and 70°C, between 50 and70°C, between 55 and 70°C, between 60 and 70°C, between 65 and 70°C, between 45 and 65°C, or between 50 and 60°C.

[0291] Exemplary Embodiments

[0292] (1 ) A process for producing lithium carbonate with carbon capture, comprising: receiving a Li salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising LiOH; and delivering the product comprising LiOH and CO2 to a carbonate production reactor to produce lithium carbonate.

[0293] (2) The process of (1 ), wherein the Li salt-containing solution comprises LiCI,Li2SO4, Li3PO4, LiNO3, Lil, or LiBr.

[0294] (3) The process of (1 ) or (2), wherein the carbonate production reactor is fluidly coupled to a device or apparatus for providing CO2.

[0295] (4) The process of (3), wherein the device or apparatus for providing CO2 is a direct air capture system.

[0296] (5) The process of any one of (1 ) to (4), wherein the electrolysis cell is a chlor-alkali membrane electrolysis cell, a chlor-alkali diaphragm electrolysis cell, a bipolar membrane electrodialysis cell, or a membrane electrolysis cell.

[0297] (6) The process of any one of (1) to (4), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a cation exchange membrane interposed between the anode compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions from the anode compartment to an opposed surface of the cation exchange membrane into the cathode compartment; an inlet through which the Li salt-containing solution is received into an interior of the electrolysis cell; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Li salt-containing solution is received into the anode compartment and Li+ions move through the cation exchange membrane to the opposed surface of the cation exchangemembrane into the cathode compartment; water is reduced at the cathode to form OH-; and the Li+ions and the OH- ions in the cathode compartment together form LiOH.

[0298] (7) The process of any one of (1) to (4), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a salt depletion compartment interposed between the cathode compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; an anion exchange membrane interposed between the anode compartment and the salt depletion compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the anode compartment; a cation exchange membrane interposed between the salt depletion compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the cathode compartment; an inlet through which the Li salt-containing solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Li salt-containing solution is received into the salt depletion compartment; Li+ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; water is reduced at the cathode to form OFT; and the Li+ions and the OH- ions in the cathode compartment together form LiOH.

[0299] (8) The process of any one of (1) to (4), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, a cation exchangemembrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the salt depletion compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the Li salt-containing solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Li salt-containing solution is received into the salt depletion compartment; Li+ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the Li+ions and the OH- ions in the base-build-up compartment together form LiOH.

[0300] (9) The process of any one of (1) to (4), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; an acid build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the salt depletion compartment is interposed between the cathode compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the salt depletion compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the acid build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the acid build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membraneand OH- ion from the opposite surface of the bipolar membrane, an inlet through which the Li salt-containing solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Li salt-containing solution is received into the salt depletion compartment; water is dissociated in the first bipolar membrane and OH- migrates into the salt depletion compartment; and the Li+ions and the OH- ions in the salt depletion compartment together form LiOH.

[0301] (10) The process of any one of (1 ) to (4), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; an anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the acid build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the acid build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the Li salt-containing solution is received into the salt depletion compartment; and at least one outlet through which the product is removedfrom an interior of the electrolysis cell, wherein in performing the process: the Li salt-containing solution is received into the salt depletion compartment; Li+ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the Li+ions and the OH- ions in the base-build-up compartment together form LiOH.

[0302] (11 ) The process of any one of (1 ) to (4), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a cation exchange membrane interposed between the anode compartment and the catalyst layer of the gas diffusion electrode, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane; an inlet through which the Li salt-containing solution is received into the anode compartment; a gas inlet through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Li salt-containing solution is received into the anode compartment; Li+ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; the gas comprising O2 is reduced at the cathode to form OFT; and the OH- ions and the Li+ions in the cathode compartment together form LiOH.

[0303] (12) The process of any one of (1 ) to (4), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment interposed between the cathode compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than thatof the diffusion layer and the catalyst layer being configured to transport negative ions; an anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the anion ion exchange membrane into the base build-up compartment; a cation exchange membrane interposed between the anode compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane into the base build-up compartment; an inlet through which the Li salt-containing solution is received into the anode compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Li salt-containing solution is received into the anode compartment; Li+ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the anion exchange membrane to the opposed surface of the anion exchange membrane into the base build-up compartment; and the OH- ions and the Li+ions in the base build-up compartment together form LiOH.

[0304] (13) The process of any one of (1 ) to (4), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the membrane electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membraneinto the base build-up compartment; a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second anion exchange membrane interposed between the salt depletion compartment and the anode compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the anode compartment; an inlet through which the Li salt-containing solution is received into the salt depletion compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Li salt-containing solution is received into the salt depletion compartment; Li+ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base build-up compartment; and the OH- ions and the Li+ions in the base build-up compartment together form LiOH.

[0305] (14) The process of any one of (1 ) to (4), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the membrane electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a first anionexchange membrane, the first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membrane into the base build-up compartment; a first cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the acid build-up compartment; a second cation exchange membrane interposed between the acid build-up compartment and the anode compartment, the second cation exchange membrane being configured to exchange ions received from the anode compartment to an opposed surface of the second cation exchange membrane into the acid build-up compartment; an inlet through which the Li salt-containing solution is received into the salt depletion compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Li salt-containing solution is received into the salt depletion compartment; Li+ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base build-up compartment; and the OH- ions and the Li+ions in the base build-up compartment together form LiOH.

[0306] (15) A system for lithium carbonate production with carbon capture, the system comprising: an electrolysis cell comprising a cathode and an anode; and a carbonate production reactor configured to receive a product comprising LiOH from the electrolysis cell and CO2to generate lithium carbonate.

[0307] (16) The system of (15), wherein the electrolysis cell is a chlor-alkali membrane electrolysis cell, a chlor-alkali diaphragm electrolysis cell, a bipolar membrane electrodialysis cell, or a membrane electrolysis cell.

[0308] (17) The system of (15) or (16), which further comprises a device or apparatus for providing the CO2 to the carbonate production reactor.

[0309] (18) The system of (17), wherein the device or apparatus for providing theCO2 is a direct air capture system.

[0310] (19) A process of producing cathode active material with reduced carbon emissions, comprising: receiving a Li salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising LiOH; delivering the product comprising LiOH and CO2 to a carbonate production reactor to produce lithium carbonate; and mixing the lithium carbonate with precursor cathode active material to produce cathode active material.

[0311] (20) A process for producing sodium carbonate with carbon capture, comprising: receiving a Na salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising NaOH; and delivering the product comprising NaOH and CO2 to a carbonate production reactor to produce sodium carbonate.

[0312] (21 ) The process of (20), wherein the Na salt-containing solution comprisesNaCI, Na2SO4, NaaPO4, NaNOa, Nal, or NaBr.

[0313] (22) The process of (20) or (21 ), wherein the carbonate production reactor is fluidly coupled to a device or apparatus for providing the CO2.

[0314] (23) The process of (22), wherein the device or apparatus for providing theCO2 is a direct air capture system.

[0315] (24) The process of any one of (20) to (23), wherein the electrolysis cell is a chlor-alkali membrane electrolysis cell, a chlor-alkali diaphragm electrolysis cell, a bipolar membrane electrodialysis cell, or a membrane electrolysis cell.

[0316] (25) The process of any one of (20) to (23), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathodecompartment; a cation exchange membrane interposed between the anode compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions from the anode compartment to an opposed surface of the cation exchange membrane into the cathode compartment; an inlet through which the Na salt-containing solution is received into an interior of the electrolysis cell; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Na salt-containing solution is received into the anode compartment and Na+ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; water is reduced at the cathode to form OH-; and the Na+ions and the OH- ions in the cathode compartment together form NaOH.

[0317] (26) The process of any one of (20) to (23), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a salt depletion compartment interposed between the cathode compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; an anion exchange membrane interposed between the anode compartment and the salt depletion compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the anode compartment; a cation exchange membrane interposed between the salt depletion compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the cathode compartment; an inlet through which the Na salt-containing solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Na salt-containing solution is received into the salt depletion compartment; Na+ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; water is reduced at the cathode to form OFT; and the Na+ions and the OH- ions in the cathode compartment together form NaOH.

[0318] (27) The process of any one of (20) to (23), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathodecompartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the salt depletion compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the Na salt-containing solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Na salt-containing solution is received into the salt depletion compartment; Na+ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the Na+ions and the OH- ions in the base-build-up compartment together form NaOH.

[0319] (28) The process of any one of (20) to (23), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; an acid build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the salt depletion compartment is interposed between the cathode compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the salt depletion compartment and being configuredto dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the acid build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the acid build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the Na salt-containing solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Na salt-containing solution is received into the salt depletion compartment; water is dissociated in the first bipolar membrane and OH- migrates into the salt depletion compartment; and the Na+ions and the OH- ions in the salt depletion compartment together form NaOH.

[0320] (29) The process of any one of (20) to (23), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; an anion exchange membrane interposed between the salt depletioncompartment and the acid build-up compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the acid build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the acid build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the Na salt-containing solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Na salt-containing solution is received into the salt depletion compartment; Na+ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the Na+ions and the OH- ions in the base-build-up compartment together form NaOH.

[0321] (30) The process of any one of (20) to (23), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a cation exchange membrane interposed between the anode compartment and the catalyst layer of the gas diffusion electrode, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane; an inlet through which the Na salt-containing solution is received into the anode compartment; a gas inlet through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Na salt-containing solution is received into the anode compartment; Na+ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; the gas comprising O2 is reduced at the cathode to form OFT; and the OH- ions and the Na+ions in the cathode compartment together form NaOH.

[0322] (31 ) The process of any one of (20) to (23), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment interposed between the cathode compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; an anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the anion ion exchange membrane into the base build-up compartment; a cation exchange membrane interposed between the anode compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane into the base build-up compartment; an inlet through which the Na salt-containing solution is received into the anode compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Na salt-containing solution is received into the anode compartment; Na+ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OFT; the OFT ions migrate through the anion exchange membrane to the opposed surface of the anion exchange membrane into the base build-up compartment; and the OH- ions and the Na+ions in the base build-up compartment together form NaOH.

[0323] (32) The process of any one of (20) to (23), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the membrane electrolysis cell and positioned in theanode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membrane into the base build-up compartment; a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second anion exchange membrane interposed between the salt depletion compartment and the anode compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the anode compartment; an inlet through which the Na salt-containing solution is received into the salt depletion compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Na salt-containing solution is received into the salt depletion compartment; Na+ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base build-up compartment; and the OH- ions and the Na+ions in the base build-up compartment together form NaOH.

[0324] (33) The process of any one of (20) to (23), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acidbuild-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the membrane electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a first anion exchange membrane, the first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membrane into the base build-up compartment; a first cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the acid build-up compartment; a second cation exchange membrane interposed between the acid build-up compartment and the anode compartment, the second cation exchange membrane being configured to exchange ions received from the anode compartment to an opposed surface of the second cation exchange membrane into the acid build-up compartment; an inlet through which the Na salt-containing solution is received into the salt depletion compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the Na salt-containing solution is received into the salt depletion compartment; Na+ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base build-up compartment; and the OH- ions and the Na+ions in the base build-up compartment together form NaOH.

[0325] (34) A system for sodium carbonate production with carbon capture, the system comprising: an electrolysis cell comprising a cathode and an anode; and a carbonate production reactor configured to receive a product comprising NaOH from the electrolysis cell and CO2 to generate sodium carbonate.

[0326] (35) The system of (34), wherein the electrolysis cell is a chlor-alkali membrane electrolysis cell, a chlor-alkali diaphragm electrolysis cell, a bipolar membrane electrodialysis cell, or a membrane electrolysis cell.

[0327] (36) The system of (34) or (35), which further comprises a device or apparatus for providing the CO2 to the carbonate production reactor.

[0328] (37) The system of (36), wherein the device or apparatus for providing theCO2 is a direct air capture system.

[0329] (38) A process for enhancing ocean alkalinity, comprising: receiving a salt solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising an alkaline compound; and delivering the product comprising an alkaline compound to a body of seawater.

[0330] (39) The process of (38), wherein the electrolysis cell is a chlor-alkali membrane electrolysis cell, a chlor-alkali diaphragm electrolysis cell, a bipolar membrane electrodialysis cell, or a membrane electrolysis cell.

[0331] (40) The process of (38), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a cation exchange membrane interposed between the anode compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions from the anode compartment to an opposed surface of the cation exchange membrane into the cathode compartment; an inlet through which the salt solution is received into an interior of the electrolysis cell; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the salt solution is received into the anode compartment and positive salt ions move through the cation exchangemembrane to the opposed surface of the cation exchange membrane into the cathode compartment; water is reduced at the cathode to form OH-; and the positive salt ions and the OH- ions in the cathode compartment together form the alkaline compound.

[0332] (41 ) The process of (38), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a salt depletion compartment interposed between the cathode compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; an anion exchange membrane interposed between the anode compartment and the salt depletion compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the anode compartment; a cation exchange membrane interposed between the salt depletion compartment and the cathode compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the cathode compartment; an inlet through which the salt solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the salt solution is received into the salt depletion compartment; positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; water is reduced at the cathode to form OFT; and the positive salt ions and the OH- ions in the cathode compartment together form the alkaline compound.

[0333] (42) The process of (38), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of thebipolar membrane, a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the salt depletion compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the salt solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the salt solution is received into the salt depletion compartment; positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the positive salt ions and the OH- ions in the base-build-up compartment together form the alkaline compound.

[0334] (43) The process of (38), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; an acid build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the salt depletion compartment is interposed between the cathode compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the salt depletion compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the acid build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the acid build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from theopposite surface of the bipolar membrane, an inlet through which the salt solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the salt solution is received into the salt depletion compartment; water is dissociated in the first bipolar membrane and OH- migrates into the salt depletion compartment; and positive salt ions and the OH- ions in the salt depletion compartment together form the alkaline compound.

[0335] (44) The process of (38), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment; a first bipolar exchange membrane interposed between the cathode compartment and the base build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, a cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; an anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the anion exchange membrane into the acid build-up compartment; a second bipolar exchange membrane interposed between the anode compartment and the acid build-up compartment and being configured to dissociate water with transport of H+ions through one surface of the bipolar membrane and OH- ion from the opposite surface of the bipolar membrane, an inlet through which the salt solution is received into the salt depletion compartment; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the salt solution is received into the salt depletion compartment;positive salt ions move through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; water is dissociated in the first bipolar membrane and OH- migrates into the base build-up compartment; and the positive salt ions and the OH- ions in the base-build-up compartment together form the alkaline compound.

[0336] (45) The process of (38), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a cation exchange membrane interposed between the anode compartment and the catalyst layer of the gas diffusion electrode, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane; an inlet through which the salt solution is received into the anode compartment; a gas inlet through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the salt solution is received into the anode compartment; positive salt ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the cathode compartment; the gas comprising O2 is reduced at the cathode to form OFT; and the OH- ions and the positive salt ions in the cathode compartment together form the alkaline compound.

[0337] (46) The process of (38), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment interposed between the cathode compartment and the anode compartment; an anode positioned to extend within the interior of the electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; an anion exchangemembrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the anion ion exchange membrane into the base build-up compartment; a cation exchange membrane interposed between the anode compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the anode to an opposed surface of the cation exchange membrane into the base build-up compartment; an inlet through which the salt solution is received into the anode compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the salt solution is received into the anode compartment; positive salt ions migrate through the cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the anion exchange membrane to the opposed surface of the anion exchange membrane into the base build-up compartment; and the OH- ions and the positive salt ions in the base buildup compartment together form the alkaline compound.

[0338] (47) The process of (38), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment and a salt depletion compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, and the salt depletion compartment is interposed between the base build-up compartment and the anode compartment; an anode positioned to extend within the interior of the membrane electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalyst layer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membrane into the base build-up compartment; a cation exchange membrane interposed between the salt depletioncompartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second anion exchange membrane interposed between the salt depletion compartment and the anode compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the anode compartment; an inlet through which the salt solution is received into the salt depletion compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the salt solution is received into the salt depletion compartment; positive salt ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base build-up compartment; and the OH- ions and the positive ions in the base build-up compartment together form the alkaline compound.

[0339] (48) The process of (38), wherein the electrolysis cell comprises: an anode compartment; a cathode compartment; a base build-up compartment, a salt depletion compartment and an acid build-up compartment interposed between the cathode compartment and the anode compartment, the base build-up compartment is interposed between the cathode compartment and the salt depletion compartment, the salt depletion compartment is interposed between the base build-up compartment and the acid build-up compartment, and the acid build-up compartment is interposed between the salt depletion compartment and the anode compartment; an anode positioned to extend within the interior of the membrane electrolysis cell and positioned in the anode compartment; a cathode comprising a gas diffusion electrode positioned to extend within the interior of the electrolysis cell and positioned in the cathode compartment, the gas diffusion electrode comprising a diffusion layer configured to diffuse gas and a catalyst layer disposed on a surface of the diffusion layer, the catalyst layer having a hydrophilicity greater than that of the diffusion layer and the catalyst layer being configured to transport negative ions; a first anion exchange membrane, the first anion exchange membrane being disposed on the catalyst layer of the gas diffusion electrode and being configured to exchange ions received from the catalystlayer of the gas diffusion electrode to an opposed surface of the first anion ion exchange membrane into the base build-up compartment; a first cation exchange membrane interposed between the salt depletion compartment and the base build-up compartment, the cation exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the cation exchange membrane into the base build-up compartment; a second anion exchange membrane interposed between the salt depletion compartment and the acid build-up compartment, the second anion exchange membrane being configured to exchange ions received from the salt depletion compartment to an opposed surface of the second anion exchange membrane into the acid build-up compartment; a second cation exchange membrane interposed between the acid build-up compartment and the anode compartment, the second cation exchange membrane being configured to exchange ions received from the anode compartment to an opposed surface of the second cation exchange membrane into the acid build-up compartment; an inlet through which the salt solution is received into the salt depletion compartment; a gas inlet positioned in the cathode compartment through which a gas comprising O2 is introduced into contact with the gas diffusion electrode; and at least one outlet through which the product is removed from an interior of the electrolysis cell, wherein in performing the process: the salt solution is received into the salt depletion compartment; positive salt ions migrate through the first cation exchange membrane to the opposed surface of the cation exchange membrane into the base build-up compartment; the gas comprising O2 is reduced at the cathode to form OH-; the OH- ions migrate through the first anion exchange membrane to the opposed surface of the first anion exchange membrane into the base build-up compartment; and the OH- ions and the positive salt ions in the base build-up compartment together form the alkaline compound.

[0340] (49) The process of any one of (38) to (48), wherein the salt solution comprises NaCI.

[0341] (50 The process of (49), wherein the NaCI is a by-product from a solar evaporation pond in a lithium brine extraction operation.

[0342] (51 ) The process of any one of (38) to (48), wherein the salt solution comprises Na2SC>4.

[0343] (52) The process of (51), wherein the Na2SC>4 is a by-product from a lithium sulfate to lithium hydroxide or lithium carbonate conversion operation.

[0344] (53) The process of any one of (38) to (52), wherein the alkaline compound comprises NaOH.

[0345] (54) The process of any one of (38) to (53), wherein the product comprising an alkaline compound is flowed directly to a body of seawater.

[0346] (55) The process of any one of (38) to (53), wherein the product comprising an alkaline compound is shipped to a body of seawater.

[0347] In the present disclosure, all terms referred to in singular form are meant to encompass plural forms of the same. Likewise, all terms referred to in plural form are meant to encompass singular forms of the same. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0348] As used herein, the term “about” refers to an approximately + / -10 % variation from a given value. It is to be understood that such a variation is always included in any given value provided herein, whether or not it is specifically referred to.

[0349] It should be understood that the compositions and methods are described in terms of "comprising," "containing," or "including" various components or steps, the compositions and methods can also "consist essentially of or "consist of the various components and steps. Moreover, the indefinite articles "a" or "an," as used in the claims, are defined herein to mean one or more than one of the element that it introduces.

[0350] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range are specifically disclosed. In particular, every range of values (of the form, "from about a to about b," or, equivalently, "from approximately a to b," or, equivalently, "from approximately a-b") disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values even if not explicitly recited. Thus, every point or individual value may serve as its ownlower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

[0351] Therefore, the present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Although individual embodiments are dis-cussed, the disclosure covers all combinations of all those embodiments. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present disclosure. If there is any conflict in the usages of a word or term in this specification and one or more patent(s) or other documents that may be referenced herein, the definitions that are consistent with this specification should be adopted.

[0352] Many obvious variations of the embodiments set out herein will suggest themselves to those skilled in the art in light of the present disclosure. Such obvious variations are within the full intended scope of the appended claims.

Claims

CLAIMS:1 . A process for producing lithium carbonate with carbon capture, comprising: receiving a Li salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising LiOH; and delivering the product comprising LiOH and CO2 to a carbonate production reactor to produce lithium carbonate.

2. The process of claim 1 , wherein the Li salt-containing solution comprises LiCI, U2SO4, LiaPO4, LiNOa, Lil, or LiBr.

3. The process of claim 1 or 2, wherein the carbonate production reactor is fluidly coupled to a device or apparatus for providing CO2.

4. The process of claim 3, wherein the device or apparatus for providing CO2 is a direct air capture system.

5. A system for lithium carbonate production with carbon capture, the system comprising: an electrolysis cell comprising a cathode and an anode; and a carbonate production reactor configured to receive a product comprising LiOH from the electrolysis cell and CO2to generate lithium carbonate.

6. The system of claim 5, which further comprises a device or apparatus for providing the CO2to the carbonate production reactor.

7. The system of claim 6, wherein the device or apparatus for providing the CO2 is a direct air capture system.

8. A process of producing cathode active material with reduced carbon emissions, comprising:receiving a Li salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising LiOH; delivering the product comprising LiOH and CO2 to a carbonate production reactor to produce lithium carbonate; and mixing the lithium carbonate with precursor cathode active material to produce cathode active material.

9. A process for producing sodium carbonate with carbon capture, comprising: receiving a Na salt-containing solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising NaOH; and delivering the product comprising NaOH and CO2 to a carbonate production reactor to produce sodium carbonate.

10. The process of claim 9, wherein the Na salt-containing solution comprises NaCI, Na2SO4, NaaPO4, NaNOa, Nal, or NaBr.

11. The process of claim 9 or 10, wherein the carbonate production reactor is fluidly coupled to a device or apparatus for providing the CO2.

12. The process of claim 11 , wherein the device or apparatus for providing the CO2 is a direct air capture system.

13. A system for sodium carbonate production with carbon capture, the system comprising: an electrolysis cell comprising a cathode and an anode; and a carbonate production reactor configured to receive a product comprising NaOH from the electrolysis cell and CO2 to generate sodium carbonate.

14. The system of claim 13, which further comprises a device or apparatus for providing the CO2to the carbonate production reactor.

15. The system of claim 14, wherein the device or apparatus for providing the CO2is a direct air capture system.

16. A process for enhancing ocean alkalinity, comprising: receiving a salt solution in an electrolysis cell comprising a cathode and an anode; applying an electric potential between the cathode and anode; producing from the electrolysis cell a product comprising an alkaline compound; and delivering the product comprising an alkaline compound to a body of seawater.

17. The process of claim 16, wherein the salt solution comprises NaCI.

18. The process of claim 17, wherein the NaCI is a by-product from a solar evaporation pond in a lithium brine extraction operation.

19. The process of any one of claims 16 to 18, wherein the salt solution comprises Na2SC>4.

20. The process of claim 19, wherein the Na2SC>4 is a by-product from a lithium sulfate to lithium hydroxide or lithium carbonate conversion operation.

21. The process of any one of claims 16 to 20, wherein the alkaline compound comprises NaOH.

22. The process of any one of claims 16 to 21 , wherein the product comprising an alkaline compound is flowed directly to a body of seawater.

23. The process of any one of claims 16 to 21 , wherein the product comprising an alkaline compound is shipped to a body of seawater.

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