Polymer coating process for electrode assemblies incorporating ion exchange materials

Abstract

The present invention provides a method for manufacturing battery cells having improved cycle life and electrical performance, and a rechargeable battery cell. [Solution] A method for manufacturing a battery cell includes the steps of: providing an ion exchange membrane containing a polymer n-mer; immersing the ion exchange membrane in a solution containing hydroxide anions to introduce the hydroxide anions and thereby convert the ion exchange membrane into a hydroxide-based ion exchange membrane; and arranging the hydroxide-based ion exchange membrane in the battery cell such that the hydroxide-based ion exchange membrane is located between a negative electrode containing zinc particles and a positive electrode containing one or more materials selected from the group consisting of nickel hydroxide (Ni(OH)2), nickel oxyhydroxide (NiOOH), manganese dioxide (MnO2), manganese oxide (MnO), iron salts (Fe(VI)), manganese salts (Mn(VI)), and permanganate salts (Mn(VII)).

Description

Technical Field

[0001] Related Applications This application claims the benefit of U.S. Provisional Application No. 63 / 016,827, filed Apr. 28, 2020, which is hereby incorporated by reference in its entirety for all purposes.

[0002] The present disclosure generally relates to the field of batteries and battery components. More specifically, the present application relates to an improved method for coating an electrode material with an ion exchange material.

Background Art

[0003] There is a great need for low-cost rechargeable battery systems with high energy density for portable devices, electric vehicles, grid storage, and other applications. Unfortunately, many battery systems require complex assembly of multiple components such as electrode materials, separators, collectors, and casings. Pinholes or leaks in the separator or casing can result in inoperability, leakage of caustic or acidic chemicals, and damage to products powered by the battery.

[0004] There is a need for battery systems that are useful for various battery chemistries, can be constructed at low cost, have high reliability, and require minimal assembly steps or individual components.

Summary of the Invention

[0005] In one embodiment, a method for manufacturing a primary battery cell or a rechargeable battery cell may include forming an electrode and coating the electrode with an n-mer. The n-mer may include a composition having repeating units in which n is selected from 1 to several million, and this includes, but is not limited to, monomers, oligomers (dimers, trimers, etc.), and branched or unbranched polymers. The n-mer coated electrode is treated to polymerize the n-mer to form an ion exchange material that coats at least a portion of the electrode. In some embodiments, the coating further includes completely or partially coating the electrode with an n-mer solution by dipping, spraying, or other means. The electrode and n-mer may be placed in a battery casing either before or after polymerization.

[0006] In some embodiments, the n-mer treatment may include polymerization. In other embodiments, the n-mer treatment may include crosslinking or curing using heat, ultraviolet light, or at least one of a chemical agent. In some embodiments, polymerization and crosslinking may occur simultaneously, while in other embodiments, crosslinking follows polymerization. In some embodiments, the polymerized and / or crosslinked ion exchange material may be positioned to define a mutual penetration interface with at least a portion of the electrode. Providing a close-contact mutual penetration interface may include completely or partially embedding the electrode in the ion exchange material, or surrounding the electrode or discontinuities of the electrode with a thin film of the ion exchange material. In one embodiment, the electrode may be a particle that is completely or partially embedded in the ion exchange material, coated with the ion exchange material, or partially in contact with the ion material. In another embodiment, the electrode particle may be mixed with the ion exchange material or otherwise mixed.

[0007] In some embodiments, the electrode may include an anode containing zinc (Zn) or ZnO. In other embodiments, the electrode is a cathode containing at least one of nickel hydroxide (Ni(OH)2), nickel oxyhydroxide (NiOOH), manganese dioxide (MnO2), manganese oxide (MnO), iron salt (Fe(VI)), manganate salt (Mn(VI)), or permanganate salt (Mn(VII)).

[0008] The electrode may include electrode particles that are at least partially smaller than 300 microns in size and filled to have a pore volume of less than 50% of the total electrode volume.

[0009] In some embodiments, the ion exchange material may include either an anion exchange material or a cation exchange material. The ion exchange material may include a polymer material to which charged functional groups are bonded.

[0010] In some embodiments, ion transport can be enabled by a liquid alkaline electrolyte in contact with the electrodes. Optionally, the electrolyte may have at least some incorporated ion exchange materials.

[0011] In one embodiment, the rechargeable battery cell may include an electrode comprising a plurality of particles and an ion exchange material that contacts and surrounds at least a portion of the particles of the electrode.

[0012] In one embodiment, the rechargeable battery cell may include an electrode containing a plurality of particles, and the ion exchange material is in contact with and completely surrounds at least some of the surfaces of the plurality of particles.

[0013] In one embodiment, a rechargeable battery cell may include an electrode containing a plurality of particles and an ion exchange material arranged to embed substantially all of the plurality of particles in the electrode.

[0014] In one embodiment, a method for manufacturing a rechargeable battery cell may include forming a plurality of particles on an electrode and embedding or mixing an ion exchange material in at least a portion of the plurality of particles on the electrode. Embedding may include at least one of melting, softening, depositing from a molten or solution, lamination, and pressure application. Several other techniques exist.

[0015] In some embodiments, the manufacturing process may involve immersing the electrodes in a liquid electrolyte.

[0016] In some embodiments, the manufacturing process may include assembling the electrodes and ion exchange material into a battery before embedding or mixing the ion exchange material into at least a portion of the particles.

[0017]

[0018] Non-exclusive and non-exclusive embodiments of this disclosure are described with reference to the following figures, and unless otherwise specified, similar reference numbers throughout the various figures refer to the same parts. [Brief explanation of the drawing]

[0019] [Figure 1] This shows a battery containing an ion exchange material in contact with an electrode material.

[0020] [Figure 2A] This exhibits various forms of contact between electrode particles and ion exchange material. [Figure 2B] This exhibits various forms of contact between electrode particles and ion exchange material. [Figure 2C] This exhibits various forms of contact between electrode particles and ion exchange material.

[0021] [Figure 3] This graph shows the discharge capacity of a Ni-Zn cell as a function of the number of cycles.

[0022] [Figure 4]The cross-sectional SEM image of the Zn electrode with anion exchange membranes laminated on both sides is shown.

[0023] [Figure 5] A more detailed SEM image of the Zn electrode with anion exchange membranes laminated on both sides is shown.

[0024] [Figure 6A] The SEM image and the related line EDX elemental scanning are shown. [Figure 6B] The SEM image and the related line EDX elemental scanning are shown.

[0025] [Figure 7] An embodiment of a method for manufacturing an n-mer-based battery is shown.

[0026] [Figure 8] Another embodiment of a method for manufacturing an n-mer-based battery is shown.

[0027] [Figure 9] The performance plots of a NiZn battery having a Zn-based anode treated with a vinylbenzyltrimethylammonium-based (VBTMA) monomer further polymerized using heat treatment are shown. The performance plots shown are (a) the discharge and (b) charge voltage profiles as a function of the anode utilization rate, (c) the capacity retention rate of the NiZn battery, and (d) the Coulomb efficiency.

[0028] [Figure 10] A graph showing the discharge energy as a percentage of the maximum discharge energy demonstrated by the cell during this test (energy retention) for a Ni-Zn cell as a function of the number of cycles.

[0029] [Figure 11] A graph showing the voltage of a NiZn cell as a function of the capacity (the upper horizontal axis is represented as % of the theoretical anode capacity, and the lower horizontal axis is represented as the areal capacity).

[0030] [Figure 12] This graph shows the discharge energy as a percentage of the maximum discharge energy demonstrated by the cell during this test (energy retention) for the MnO2-Zn cell, as a function of the number of cycles.

[0031] [Figure 13] This graph shows the voltage of a MnO2-Zn cell as a function of capacitance (expressed as a percentage of the theoretical cathode capacitance). [Modes for carrying out the invention]

[0032] This disclosure relates, in part, to battery cells having improved cycle life and electrical performance in use. For example, the battery cells may exhibit a higher battery discharge voltage, a higher discharge capacity, lower internal resistance, and a higher discharge rate. In some embodiments, the battery cells of the disclosure have a long cycle life at high discharge currents.

[0033] Figure 1 shows a rechargeable battery cell system 100, including a casing 102 surrounding various battery components. The battery components may include current collectors 110 and 112 that facilitate charging and discharging of the battery cell system 100. Other components include electrode materials 120 and 122 that contact the current collectors 110 and 112, respectively. The electrode materials 120 and 122 are separated from each other by a separator 130 that allows only the flow of ions between the materials. In one embodiment, the electrode materials may be coated with an ion exchange material that also acts as a separator. The rechargeable battery cell system 100 may include an anode, cathode, ion exchange, and other materials and components as described below.

[0034] electrode Electrode materials may include materials formed as thin films or structured patterns such as columns, needles, grooves, or slots. In some embodiments, electrodes may be loosely arranged materials, tightly bonded or sintered structures, or solid continuous pore structures. In one embodiment, electrodes may be formed from particles provided in various forms such as powders, granules, pellets, or nanomaterials. In certain embodiments, particles may have an average size (diameter or longest dimension) of about 0.1 μm to 300 μm, and in certain embodiments, about 100 μm to 1 μm. In some embodiments, relatively uniform particle sizes may be used, while in other embodiments, materials of non-uniform sizes may be used. Particles can be processed to increase their effective surface area. In some embodiments, particles can be bonded together by heating, melting, fusing, or sintering. In other embodiments, additional binders may be used to hold the particles together.

[0035] Current collector At least a portion of the electrode material is positioned in contact with the current collector. The current collector supplies current for the electrode reaction during charging and recovers the current generated during discharge. The current collector is typically formed from a material that has high conductivity and is inert to electrochemical battery cell reactions. The current collector can be molded in the form of a plate, foil, mesh, porous sponge, punched or slotted metal, or expanded metal.

[0036] Examples of materials for the current collector include Ni, Ti, Cu, Al, Pt, V, Au, Zn, Fe, and alloys of two or more of these metals, such as stainless steel, bronze, and brass. Other embodiments may include graphite cloth, graphite foil, copper sheets, or slotted mesh or woven brass.

[0037] Anode material Anode materials for electrodes can include a wide range of materials such as zinc, aluminum, magnesium, iron, and lithium, as well as other metals in pure, oxide, or salt form, or combinations thereof. In some embodiments, relatively pure Zn, ZnO, or mixtures of Zn and ZnO can be used. In the case of a rechargeable zinc anode, the electrochemically active material is zinc oxide powder or a mixture of zinc and zinc oxide powder. Zinc oxide dissolves in an alkaline electrolyte to form zincate (Zn(OH)4)₄ 2- ) can be formed. Zinc oxide and / or zinc salts are reduced to zinc metal during the charging process.

[0038] More broadly, anode materials may include the following:

[0039] Any metal M, metal oxide MOx, or metal salt having a redox potential E0 lower than the redox potential of the cathode material.

[0040] Any metal oxide MOx having a redox potential E0 lower than the redox potential of the cathode material.

[0041] Any alloy of any metal MM1M2...Mn, mixed oxides, or mixed salts having an E0 lower than the E0 of the cathode material.

[0042] Any polymer capable of accommodating ions in its structure, having a redox potential E0 lower than the redox potential of the cathode material.

[0043] Any mixture of one or more of the above types of materials.

[0044] Cathode material The cathode material for the electrode may include a wide range of materials such as metals or metal-containing compounds, for example, iron salts (Fe(VI)), manganese salts (Mn(VI)), permanganate salts (Mn(VII)), nickel hydroxide (Ni(OH)2), nickel oxyhydroxide (NiOOH), manganese dioxide (MnO2), manganese oxide (MnO), or any combination thereof.

[0045] More broadly, cathode materials may include the following:

[0046] Any metal M, metal oxide MOx, or metal salt having a redox potential E0 greater than the redox potential of the anode material.

[0047] Any metal oxide MOx having a redox potential E0 greater than the redox potential of the anode material.

[0048] Any metal MM1M2...Mn alloy having an E0 greater than the E0 of the anode material.

[0049] Metal fluorides (MFn) have a redox potential greater than that of the anode material.

[0050] Any alloy MM1M2...MnOxFm where n is 2 or greater and m is 0 or greater.

[0051] Any polymer capable of accommodating ions in its structure, having a redox potential E0 greater than that of the anode material.

[0052] Any mixture of one or more of the above types of materials.

[0053] Additives and binders Various additives can be used to improve the electrochemical, electrical, or mechanical properties of the electrodes. For example, electrochemical performance can be improved by adding nickel, nickel hydroxide, nickel oxyhydroxide, or nickel oxide-containing cathode materials that incorporate or can be coated with small amounts of cobalt oxide, strontium hydroxide (Sr(OH)2), barium oxide (BaO), calcium hydroxide (Ca(OH)2), Fe3O4, calcium fluoride (CaF2), or yttrium oxide (Y2O3) to improve battery cell performance. As another example, electrodes may contain oxides such as bismuth oxide, indium oxide, and / or aluminum oxide. Bismuth oxide and indium oxide can interact with zinc to reduce gas generation at the electrodes. Bismuth oxide may be provided at a concentration of about 1–20% by weight of the dry anode formulation. Indium oxide may be present at a concentration of about 0.05–10% by weight of the dry anode formulation. Aluminum oxide can be supplied at a concentration between approximately 1 and 10% by weight of the dry anode formulation.

[0054] Furthermore, some additives can participate in chemical processes during the battery cycle to generate new phases in the electrodes, thereby improving the battery's cycle performance and stability. Such additives may include, but are not limited to, Bi2O3-containing compositions.

[0055] In certain embodiments, one or more additives may be included to improve the corrosion resistance of the zinc electrode material. Specific examples of anions that may be included to reduce the solubility of zinc in the electrolyte include phosphates, fluorides, borates, zincates, silicates, or stearates. Generally, these anions may be present in the electrode at concentrations up to about 10% by weight of the dry electrode formulation.

[0056] Furthermore, additives that improve electrical properties such as conductivity can be added. For example, various carbonaceous materials, including powdered or fibrous carbon such as graphite, coke, Ketjenblack, and acetylene black, can be used as electrode additives. Carbonaceous nanomaterials, such as single-walled or multi-walled carbon nanotubes, carbon nanofibers, multi-walled carbon nanoparticles, carbon nanowhiskers, or carbon nanorods, can also be used.

[0057] The additive may be provided in a mixture or solution as a chemically homogeneous component, may be co-precipitated, or may be coated onto particles.

[0058] In one embodiment, the mechanical properties of an electrode can be improved by adding a binder to increase its mechanical strength and reduce bending or cracking. Examples of binders include polymer materials such as polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), polyisobutylene (PIB), polyvinyl alcohol (PVA), polyacrylic acid or its salts, polyvinyl acetate, carboxymethylcellulose (CMC), styrene-butadiene rubber (SBR), polyethylene oxide (PEO), polybutylene terephthalate (PBT), or polyamide; silicone elastomers such as polyvinylidene fluoride (PVDF) or polydimethylsiloxane (PDMS); or rubber materials such as natural rubber (NR), ethylene propylene rubber (EPM), or ethylene propylene diene monomer rubber (EPDM).

[0059] Ion exchange materials Ion exchange materials are generally selective for the transport of either cations or anions. Anion-selective ion exchange materials can be used alone, cationic-selective ion exchange materials can be used alone, or they can be used in combination. In one embodiment, the ion exchange material may be an organic or polymer material to which a strongly acidic group is bonded, such as a sulfonic acid containing sodium polystyrene sulfonate or polyAMPS. Alternatively, the ion exchange material may be an organic or polymer material to which a strongly basic group is bonded, such as a quaternary amino group containing a trimethylammonium group (e.g., polyAPTAC). In another embodiment, the ion exchange material may be an organic or polymer material to which a weakly acidic group containing a carboxylic acid group is bonded. Alternatively, the ion exchange material may be an organic or polymer material to which a weakly basic group is bonded, typically characterized by primary, secondary, and / or tertiary amino groups (e.g., polyethyleneamine).

[0060] Ion exchange materials can be provided as fully or partially embedded polymers, particle mixtures, membranes or films, microparticles or beads, or coatings to interact with electrode materials. The anode alone, the cathode alone, or both the anode and the cathode can be configured to interact with ion exchange materials, which may be the same or different materials for each electrode.

[0061] Processing of ion exchange materials In some embodiments, ion exchange materials can be manufactured using n-mer-based coating, polymerization, or crosslinking processes. The n-mer may comprise compositions having repeating units where n is selected from 1 to several million, including, but not limited to, monomers, oligomers (dimers, trimers, etc.), and branched or unbranched polymers. Typically, the n-mer can be retained in solution using a suitable solvent, or may be fused alternatively or additionally. The n-mer can be coated onto electrode materials, including particles of various sizes (including nanoscale to millimeter-scale particles), strips, plates, needles, porous structures, or more complex structures. Polymerization by heat, UV, crosslinking agents, or a combination thereof can produce polymerized ion exchange materials. In some embodiments, the polymerized ion exchange material is further crosslinked. In some embodiments, the polymerization and crosslinking steps occur simultaneously. In some embodiments, an ion exchange step is used to convert the ion exchange material into a suitable form (e.g., OH form). The ion exchange step may include immersing the battery components in a solution containing the required ions (e.g., KOH solution). The ion exchange step may occur as a separate step or during immersion of the battery components in the electrolyte. In some embodiments, electrode particles or structures may be coated with an n-mer and crosslinked before assembly into the battery or placement in the casing, while in other embodiments, the n-mer may be added and crosslinked after the electrode particles or structures are placed in the battery, placed on the collector, or held in the casing, containment shell, or containment area. In one embodiment, the n-mer material may be applied by immersing the electrode material or a plurality of particles formed on the electrode in a bath of n-mer solution. In other embodiments, the n-mer material may be directed to contact the electrode material by spraying, dropping, printing, melting, or other means.

[0062] In some embodiments, a suitable n-mer for forming an ion exchange material may have a set of functional groups, including an ionogenic functional group, a functional group for polymerization, and / or a functional group for crosslinking. The ionogenic functional group may include one or more primary, secondary, tertiary, or quaternary amino groups in basic or salt form, a carboxyl group in acidic or salt form, or a sulfo group in acidic or salt form.

[0063] Functional groups for polymerization and functional groups for crosslinking can be independently selected from the following list.

[0064] Halogens (-Cl, -Br, or -I)

[0065] Carboxy group (-COOH)

[0066] Amine (-NH2,-NH-)

[0067] Alcohol (-OH)

[0068] Thio(-SH)

[0069] -N=C=O

[0070] -N=C=S

[0071] -C=CH2

[0072] -C=CH-CH3

[0073] -C≡CH

[0074] -C≡C-CH3

[0075] -CH=O

[0076] -NH-NH2

[0077] -N=N +=N-

[0078] Epoxy

[0079] In one embodiment, polymerization and / or crosslinking may be facilitated by the addition of a crosslinking agent molecule having a different structure from the n-mer. The crosslinking agent molecule creates molecular crosslinks between the n-mer molecule or the polymerized n-mer molecule. The crosslinking agent molecule may have at least one functional group from the table above. The molar ratio of the crosslinking agent molecule to the n-mer may be in the range of 0.5% to 50%. For example, in the case of an n-mer such as (vinylbenzyl)trimethylammonium chloride (VBTMA-Cl), crosslinking can be carried out using divinylbenzene (DVB) having two functional groups -C=CH2. As another example, an n-mer-containing -OH (especially phenol) can be polymerized by the addition of formaldehyde (CH2O) having the functional group -CH=O.

[0080] In some embodiments, the n-mer suitable for forming an ion exchange material is (3-acrylamidopropyl)trimethylammonium compound, [3-(methacryloylamino)propyl]trimethylammonium compound, [2-(acryloyloxy)ethyl]trimethylammonium compound, [2-(methacryloyloxy)ethyl]trimethylammonium compound, It may contain (vinylbenzyl)trimethylammonium compounds, 2-acrylamido-2-methyl-1-propanesulfonic acid compounds, 3-sulfopropyl acrylate compounds, 3-sulfopropyl methacrylate compounds, diallyldimethylammonium compounds, vinylbenzenesulfonate compounds, or N-(3-aminopropyl)methacrylamide compounds.

[0081] electrolyte Electrolytes are used to maintain high ionic conductivity between electrodes. Electrolytes can be aqueous, solvent-based, solid polymers, or ionic liquids. In some embodiments, the electrolyte can be semi-solid or gelling. Gelling agents may include polymers that absorb the liquid in the electrolyte solution and swell. Such polymers may include polyethylene oxide, polyvinyl alcohol, and polyacrylamide, polyacrylic acid, or polyacrylate.

[0082] In another embodiment, the electrolyte may be a solid electrolyte. In another embodiment, the electrolyte may be formed as a solid material having absorbed water. For example, KOH is exposed to moist air.

[0083] In another embodiment, the electrolyte can be formed from an ion exchange material as described above in the section on "ion exchange materials".

[0084] In one embodiment, an aqueous alkaline electrolyte can be used. The alkaline electrolyte may contain alkalis such as potassium hydroxide, sodium hydroxide, lithium hydroxide, or calcium hydroxide, or it may contain inorganic salts such as zinc bromide.

[0085] Separator The separator may be replaced with (or used in combination with) an ion exchange membrane or film. Conventional porous polymer separators or ion exchange separators may be provided as polymer membranes or films. Typically, the separator is placed between the anode and cathode and acts to prevent the anode and cathode from having an internal electrical short circuit. Furthermore, the separator may also act to retain electrolytes, particularly in battery systems using different cathode and anode electrolyte solutions. In some embodiments, the separator has a porous structure or a structure with several perforations that are chemically stable to the electrolyte while allowing ions to pass through. In some embodiments, the separator is non-porous and comprises a layer of solid electrolyte material, a solid or gel polymer electrolyte, or an ion exchange material. In some embodiments, the separator adheres to the electrodes and can bond the electrodes together during the application of pressure, temperature, or a combination of pressure and temperature. In some embodiments, one or more separators can be formed by coating electrodes or particles that collectively form electrodes. The separator can be formed from a nonwoven fabric or film having a microporous structure made of glass, polypropylene, polyethylene, resin, or polyamide. Alternatively, the separator may be composed of a metal oxide film or resin film combined with a metal oxide having multiple pores.

[0086] In some embodiments, the electrodes within the battery are covered with an ion exchange material of sufficient thickness to provide complete coverage of the electrode surfaces and to avoid electrical contact between the anode and cathode, even when they are arranged in direct contact with each other without a separator. In these embodiments, the battery does not have a separator as a separate component.

[0087] process In one embodiment, a dry mixing process can be carried out in which various anode and cathode materials, as well as additives and binders, are mixed while drying. Optional processing steps, such as heating, fusing, compressing, and melting of the ion exchange materials, can be performed before the mixture is placed in the battery casing. In other embodiments, optional processing steps, such as heating, fusing, compressing, and melting of the ion exchange materials, can be performed after the mixture has been placed in the battery casing. A liquid electrolyte can be added before sealing the battery casing.

[0088] In other embodiments, a wet mixing process may be used instead. In a wet mixing process, one or more solvents may be added at the start of the mixing process or during the mixing process, or one or more components may be used in the form of a dispersion or suspension. The solvents may then be removed after the mixing process or after the manufacturing process.

[0089] In other embodiments, various individual components may be manufactured using different methods. For example, part of the electrode may be manufactured using a dry mixing process, and part of the electrode may be manufactured using a wet process. According to yet another embodiment, it is possible to combine both dry and wet processes for different components.

[0090] In other embodiments, electrodes may be manufactured using a dry mixing process and coated with an n-scale ion exchange material using a wet process. In other embodiments, after the mixture is placed in a battery casing, processing steps such as crosslinking, heating, fusing, compression, and melting of the ion exchange material may be performed.

[0091] Battery and cell design Battery cells can have any of several different shapes and sizes. For example, coin, prismatic, pouch, or cylindrical cells can be used. The cylindrical cells of the present invention can have the diameter and length of conventional AAA, AA, A, C or D or 18650, 26650, or 21700 cells. Custom cell designs can be used in some applications. For example, prismatic cell designs can be used for various larger cell forms used in portable or vehicle applications, as well as various non-portable applications. Battery packs can be specially designed for specific tools or applications. Battery packs may include one or more battery cells, as well as appropriate casings, contacts, and conductive lines, to enable reliable charging and discharging in electrical equipment.

[0092] Figures 2A to 2C show portions of rechargeable battery cells 200, 210, and 220, which include electrodes and ion exchange material arranged to define a mutual penetration interface with at least a portion of the electrodes. Providing a close-contact mutual penetration interface may include completely or partially embedding the electrodes in the ion exchange material, or surrounding the electrodes or discontinuities of the electrodes with a thin film of ion exchange material. In one embodiment, the electrodes may be particles that are completely or partially embedded in the ion exchange material, coated with the ion exchange material, or partially in contact with the ion material. In one embodiment, coated electrodes may be achieved using an n-mer based process that includes coating the electrodes with n-mers that can be crosslinked to form an ion exchange material.

[0093] Figure 2A shows a rechargeable battery cell 200 including a collector 202 that contacts at least some of a plurality of electrochemically active particles 206. Another set of particles 206 is also in contact and partially embedded in an ion exchange membrane 204. This ion exchange membrane can be formed by partially melting, fusing, laminating, or compressing the particles 206. An electrolyte (not shown) may also be provided to fill the particle pore spaces and to contact the ion exchange membrane 204.

[0094] Figure 2B shows a rechargeable battery cell 210 including a collector 212. Each of the particles 216 is in contact with and surrounded by an ion exchange membrane 214. This ion exchange membrane can be provided by coating the particles 216 before the particles are incorporated into the rechargeable battery cell. An electrolyte (not shown) may also be provided to fill the particle pore spaces and to come into contact with the ion exchange membrane 214.

[0095] Figure 2C shows a rechargeable battery cell 220 including a collector 222 that is in contact with at least some of a plurality of electrochemically active particles 226. Another set of particles 226 is also in contact and is completely embedded in an ion exchange membrane 224. This ion exchange membrane can be positioned by melting or fusing it to the particles 226. An electrolyte (not shown) may also be provided in contact with the ion exchange membrane 214.

[0096] Example 1 This example describes the production of a ZnO-based anode for alkaline rechargeable batteries having an anion exchange film embedded in the surface electrodes by lamination. The following paste composition was used for anode preparation: ZnO (94 w.%), carbon nanotubes (1 w.%), and PTFE (5 w.%). Using this composition, a viscous paste with 27 w.% water was prepared. The paste was spread to form a uniform film up to approximately 0.6 mm thick. The film was applied to a brass wire mesh current collector. The anode film applied to the current collector was vacuum-dried overnight at 70°C and then compressed using a calender roller press. Subsequently, a 37 mm × 25 mm electrode was cut from the film on the current collector, and nickel strip tabs were attached to the electrode. Anion exchange films were laminated on both sides using a SKY-325R6 laminating machine at 140°C and speed setting 2.

[0097] Example 2 This example describes the fabrication of a rechargeable alkaline nickel-zinc cell having a ZnO-based anode with an anion exchange film embedded in the surface electrode. The cell anode was prepared as described in Example 1 above. A commercially available sintered nickel electrode was used as the cathode. The cathode size was 40 mm × 27 mm, and the capacity was 27 mAh / cm². 2 Nickel strips were welded to each cathode to form electrode tabs. Each cathode was sealed with a paper separator. The anode was sandwiched between the two cathodes forming the electrode stack. The electrode stack was placed inside a polypropylene pouch fitted with a pressure relief valve so that the electrode tabs protruded from the pouch. 2 ml of electrolyte (20% KOH aqueous solution) was added to the cell. The cell was then sealed using a heat sealer.

[0098] The cells were left immersed for 4 hours, then charged, and subsequently subjected to charge-discharge cycles using the following test protocol: constant current charging at 162 mA to 1.95 V, followed by constant voltage charging to a total capacity of 173 mAh, and constant current discharge to 1.2 V or 173 mAh. The tests were conducted at room temperature. The discharge capacity of the Ni-Zn cells as a function of the number of cycles is shown in Figure 3 as Graph 300.

[0099] Example 3 This example describes the production of a Zn metal anode for alkaline rechargeable batteries having an anion exchange film embedded in the surface electrodes by lamination. The following paste composition was used for anode preparation: Zn (79 w.%), ZnO (14.5%), Bi2O3 (0.5%), PTFE (5.8 w.%), CMC (0.2%). Using this composition, a viscous paste with 12 w.% water was prepared. The paste was spread to form a uniform film up to approximately 0.6 mm thick. The film was applied to a brass wire mesh current collector. The anode film applied to the current collector was vacuum-dried overnight at 70°C and then compressed using a calender roller press. Subsequently, a 37 mm × 25 mm electrode was cut from the film on the current collector, and nickel strip tabs were attached to the electrode. Anion exchange films were laminated on both sides using a SKY-325R6 laminating machine at 140°C and speed setting 2.

[0100] Cross-sectional samples were prepared from the formed anodes using pot and polish techniques. Cross-sectional SEM images and EDX analysis results are shown in Figures 4 to 6.

[0101] Figure 4 shows a cross-sectional SEM image of a Zn electrode with anion exchange films laminated on both sides. An anode 400 containing anion exchange films 401 is laminated on both sides of an electrochemically active layer 402 in which a brass mesh current collector 403 is embedded. The electrochemically active layer consists of Zn metal particles 404, which are mixed with ZnO, Bi2O3 as additives, and PTFE as a binder.

[0102] Figure 5 shows a cross-sectional SEM image 500 of a Zn electrode with anion exchange films stacked on both sides. The image shows a magnified view of the close contact between the film anion exchange material 501 (corresponding to the film anion exchange material 401 in Figure 4) and the electrode electrochemically active mass 502 (corresponding to the electrochemically active layer 402 in Figure 4).

[0103] Figure 6A shows SEM images (image 600A and EDX elemental cross-sectional scan line 602A). Figure 6B is graph 602B, which shows the close interface between the anion exchange film 601A (corresponding to the film anion exchange material 401 in Figure 4) and the Zn particles 604 (corresponding to the Zn particles 404 in Figure 4) at the anode, and is a related EDX elemental cross-sectional scan (taken along scan line 602A in Figure 600A). The elemental distribution shows overlapping signals for Zn (Zn particles) and C, O, and Br (anion exchange film components).

[0104] Figure 7 shows one embodiment of process 700 for an n-mer-based treatment for coating an electrode with an ion exchange material. The process steps include battery casing preparation 702. In one embodiment, step 702 includes placing an electrode material formed from particles provided in various forms such as powder, granules, pellets, or nanomaterials into a casing. In step 704, the particles are coated by spraying or other means using a functionalized n-mer. In step 706, the n-mers are polymerized using heat, UV, or a crosslinking agent to form an ion exchange material that completely or partially coats the electrode. In step 707, the polymerized n-mers are further crosslinked. Steps 706 and 707 may be performed simultaneously or sequentially. In some embodiments, the ion exchange material is positioned to define a mutual penetration interface with at least a portion of the electrode. Providing a close-contact mutual penetration interface may include completely or partially embedding the electrode in the ion exchange material. In one embodiment, the electrode may be a particle that is completely or partially embedded in the ion exchange material, coated with the ion exchange material, or partially in contact with the ion material. In another embodiment, the electrode particles may be mixed with an ion exchange material or otherwise mixed.

[0105] In some embodiments, steps 704 to 706 can be repeated using the same electrode material to enable layer-by-layer construction. In other embodiments, different electrode materials can be used with the same or different n-mer materials to provide, for example, a cathode having a first type ion exchange material coating and an anode having a second type ion exchange coating, both of which are placed within a battery casing. In the final step 708, the battery can be prepared by providing any necessary electrical interconnections and sealing the casing.

[0106] Figure 8 shows one embodiment of process 800 for an n-mer based treatment for coating an electrode with an ion exchange material. The process steps include coating the electrode 802. In step 804, a functionalized n-mer is coated onto the electrode. Step 804 can be performed on the same coating line as the electrode using extrusion, slot die coating, or doctor blade coating. In some embodiments, step 804 can be performed as a batch process by immersing the coated electrode in a bath of n-mer solution or molten material. In step 806, the n-mer coated onto the electrode is polymerized using heat, UV, or a crosslinking agent to form an ion exchange material that completely or partially coats the electrode. In step 807, the polymerized n-mer is further crosslinked. Steps 806 and 807 may be performed simultaneously or sequentially. In some embodiments, the ion exchange material is positioned to define a mutual penetration interface with at least a portion of the electrode. Providing a close-contact mutual penetration interface may include completely or partially embedding the electrode in the ion exchange material. In one embodiment, the electrodes may be particles that are completely or partially embedded in the ion exchange material, coated with the ion exchange material, or partially in contact with the ion material. In another embodiment, the electrode particles may be mixed with the ion exchange material or otherwise mixed.

[0107] In some embodiments, steps 804 to 806 can be repeated using the same electrode material to enable layer-by-layer construction. In other embodiments, different electrode materials can be used with the same or different n-mer materials to provide, for example, a cathode having a first type of ion exchange material coating and an anode having a second type of ion exchange coating. In the final step 808, the battery can be assembled by stacking, winding or folding the anode, cathode and separator, filling the battery with electrolyte, providing any necessary electrical interconnections, and sealing the casing.

[0108] Example 4 This example describes an n-mer system coating for a Zn-based anode for alkaline rechargeable batteries, in which an anion-exchange n-mer, polymerized by heat treatment while immersed in an alkaline electrolyte and subsequently by an anion exchange reaction, is embedded in the electrode.

[0109] The following paste composition was used for anode preparation: Zn (79.6 w.%), ZnO (14.6 w.%), Bi2O3 (0.5 w.%), PTFE (5.1 w.%), and CMC (0.2 w.%). Using this composition, a viscous paste containing 10 w.% water was prepared. The paste was spread to form a uniform film with a thickness of approximately 0.6 mm. The film was applied to a brass wire mesh current collector. The anode film applied to the current collector was vacuum-dried overnight at 70°C and then compressed using a calender roller press. Subsequently, a 37 mm × 25 mm electrode was cut from the film on the current collector, and nickel strip tabs were attached to the electrode.

[0110] The electrodes were immersion-coated with a 25 w.% solution of (vinylbenzyl)trimethylammonium chloride (VBTMA-Cl) in isopropanol (IPA). The electrodes were dried in air at room temperature. The electrodes were then heat-treated at 160°C in vacuum for 4 hours. The heat treatment resulted in the polymerization of VBTMA-Cl and the formation of poly-(vinylbenzyl)trimethylammonium chloride, which is insoluble in IPA or water. The electrodes were passed through a SKY-325R6 laminating machine at 140°C using speed setting 4 to smooth the polymer-coated electrode surface.

[0111] Three electrochemical cells were assembled using Zn electrodes treated with VBTMA-Cl, with NiOOH and a 50% charged NiOOH / Ni(OH)2 reference electrode as counter electrodes. The cells were filled with a 20% KOH aqueous solution and left immersed for 24 hours.

[0112] During processing, chemical transformations by the VBTMA compound include polymerization during heat treatment and ion exchange during immersion in KOH solution. [ka] The Cl- anion is replaced by an OH- anion. The overall process leads to the formation of anion-exchange polymer-coated electrode particles. The polymer is ionic and can transport OH- ions to the electrode.

[0113] The rated capacity of the cell was defined as the theoretical capacity of the Zn electrode. The cell was left immersed for 24 hours before testing, then discharged at the C / 4 rate to 30% of the theoretical Zn capacity, and subsequently subjected to charge-discharge cycles using the following test protocol: constant current charging at the C / 4 current rate up to 1.8V, followed by constant voltage charging at the C / 4 current cutoff to 30% of the theoretical Zn capacity, and constant current discharge at the C / 4 rate to 1.2V or 173mAh. The tests were conducted at room temperature. The discharge voltage versus capacity curve of the cell as a function of the number of cycles is shown in Figure 9, which includes chart a) for the first 50 cycles. Graph b) in Figure 9 shows the voltage between the Zn electrode and the reference electrode during charging for the first 50 cycles. Charts c) and d) in Figure 9 show the capacity retention rate and Coulomb efficiency of the cell for the first 50 cycles, respectively.

[0114] In fact, electrodes treated with VBTMA compounds exhibit good cycle stability and high Coulomb efficiency at a relatively high utilization level of 30% of their theoretical capacity.

[0115] Example 5 This example describes the production of a ZnO-based anode for alkaline rechargeable batteries having an anion exchange film embedded in the surface electrode by lamination. The following paste composition was used for anode preparation: ZnO (89.4 w.%), carbon nanotubes (1 w.%), PTFE (4.8 w.%), CMC (0.2%), KOH (4.8%). Using this composition, a viscous paste with 21 w.% water was prepared. The paste was spread to form a uniform film with a thickness of 300 μm. The film was applied to a brass wire mesh current collector. The anode film applied to the current collector was vacuum-dried overnight at 70°C and then compressed using a calender roller press. Subsequently, a 37 mm × 25 mm electrode was cut from the film on the current collector, and nickel strip tabs were attached to the electrode. The electrode prepared as described above was laminated with anion exchange films on both sides using a high-temperature lamination press set to 160°C for 150 seconds, followed by 10°C for 150 seconds.

[0116] Example 6 This example describes the fabrication of a rechargeable alkaline nickel-zinc cell having a ZnO-based anode with an anion exchange membrane embedded in the surface electrode. The cell anode was prepared as described in Example A above. A commercially available sintered nickel electrode was used as the cathode. The cathode size was 40 mm × 27 mm and the capacity was 27 mAh / cm². Nickel strips were welded to each cathode to form electrode tabs. Each cathode was sealed with a paper separator. An electrode stack was formed by pairing an anode with one of the cathodes. The electrode stack was placed inside a polypropylene pouch so that the electrode tabs protruded from the pouch. 1.5 ml of electrolyte (20% KOH aqueous solution) was added to the cell. The cell was then sealed using a heat sealer.

[0117] The cells were left immersed for 24 hours, then charged, and subsequently subjected to charge-discharge cycles using the following test protocol: constant current charging at 162 mA up to 1.95 V, followed by constant voltage charging up to a total capacity of 173 mAh, and constant current discharge up to 1.2 V or 173 mAh. The tests were conducted at room temperature. As a function of the number of cycles, the discharge energy as a percentage of the maximum discharge energy demonstrated by the cell during this test (energy retention) for the Ni-Zn cell is shown in Graph 1000 of Figure 10. Furthermore, the related Graph 1100 in Figure 11 is a graph showing the voltage of the NiZn cell as a function of capacity (the upper horizontal axis is expressed as a percentage of the theoretical anode capacity, and the lower horizontal axis is expressed as area capacity). Example 7 This example describes an alkaline battery having a MnO2-based cathode and a Zn metal-based anode. The cathode size was 40 mm × 27 mm, and the anode size was 37 mm × 25 mm. Both the anode and cathode in this example were covered with anion exchange material in the form of a film using a high-temperature lamination press set to 160°C for 150 seconds, followed by 10°C for 150 seconds. The cathode and anode were stacked with a polypropylene nonwoven fabric separator in between the electrodes. The electrode stack was placed inside a polypropylene pouch so that the electrode tabs protruded from the pouch. 1.5 ml of electrolyte (20% KOH aqueous solution) was added to the cell. The cell was then sealed using a heat sealer.

[0118] The rated capacity of the cell was defined as the theoretical cathode capacity (617 mAh / g MnO2). The cell was left immersed for 2 hours and subjected to charge-discharge cycles using the following test protocol: constant current discharge at C / 5 up to 0.3V or 20% of rated capacity, followed by constant current / constant voltage charging at C / 5 up to 24% of 1.8V of rated capacity, and current cutoff at C / 25. The test was performed at room temperature. The discharge energy as a percentage of the maximum discharge energy demonstrated by the cell during this test (energy retention) for the MnO2-Zn cell is shown in Graph 1200 of Figure 12 as a function of the number of cycles. Furthermore, the related Graph 1300 of Figure 13 shows the voltage of the MnO2-Zn cell as a function of capacity (expressed as a percentage of the theoretical cathode capacity).

[0119] The preceding description refers to the accompanying drawings illustrating specific exemplary embodiments that form part of the present disclosure and enable the implementation of this disclosure. These embodiments are described in sufficient detail to enable those skilled in the art to implement the concepts disclosed herein, and it should be understood that various modifications can be made to the disclosed embodiments and other embodiments can be utilized without departing from the scope of this disclosure. Therefore, the preceding detailed description should not be construed as restrictive.

[0120] Throughout this specification, any reference to “one embodiment,” “an embodiment,” “an example,” or “an example” means that the particular features, structures, or characteristics described in relation to an embodiment or example are included in at least one embodiment of this disclosure. Therefore, the appearance of the expressions “in one embodiment,” “in an embodiment,” “an example,” or “an example” in various parts of this specification does not necessarily refer to the same embodiment or example. Furthermore, particular features, structures, databases, or characteristics can be combined in any suitable combination and / or partial combination in one or more embodiments or examples. Additionally, the drawings provided herein are for illustrative purposes to those skilled in the art, and it should be understood that the drawings are not necessarily drawn to scale.

[0121] Those skilled in the art, having benefited from the teachings presented in the foregoing description and the associated drawings, will likely recall numerous modifications and other embodiments of the invention. Therefore, it is understood that the invention is not limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims. It is also understood that other embodiments of the invention may be carried out in the absence of elements / steps not specifically disclosed herein.

Claims

1. A method for manufacturing a battery cell, The steps of forming electrodes and The steps include coating the electrode with an n-mer, The steps include processing the n-mer coated electrode to polymerize the n-mer and form an ion exchange material that covers at least a portion of the electrode, A method for manufacturing battery cells, including [the specified part of the method].

2. The method for producing a battery cell according to claim 1, wherein the n-mer comprises at least one of monomers, oligomers, and branched or unbranched polymers.

3. The method for manufacturing a battery cell according to claim 1, wherein the n-mer can be placed in a solution.

4. A method for manufacturing a battery cell according to claim 1, wherein the n-mer can be melted.

5. A method for manufacturing a battery cell according to claim 1, further comprising a crosslinking step accelerated by at least one of heat, ultraviolet light, or chemical agent-induced crosslinking.

6. The method for manufacturing a battery cell according to claim 5, wherein the crosslinking step is performed after the polymerization step.

7. The method for manufacturing a battery cell according to claim 5, wherein the crosslinking step is performed simultaneously with the polymerization step.

8. A method for manufacturing a battery cell according to claim 1, further comprising the step of assembling the electrode and the n-mer into a battery casing before polymerization.

9. The method for manufacturing a battery cell according to claim 1, wherein the polymerized ion exchange material is arranged to define a mutual penetration interface with at least a portion of the electrode.

10. The method for manufacturing a battery cell according to claim 1, wherein the electrode further comprises at least one of zinc, aluminum, magnesium, iron, lithium, and their respective oxides or salts.

11. The method for manufacturing a battery cell according to claim 1, wherein the electrode further comprises a zinc (Zn)-containing anode.

12. The electrode is nickel hydroxide (Ni(OH) ２ ), nickel oxyhydroxide (NiOOH), manganese dioxide (MnO ２ A method for producing a battery cell according to claim 1, wherein the cathode comprises at least one of manganese oxide (MnO), iron salt (Fe(VI)), manganese salt (Mn(VI)), and permanganate (Mn(VII)).

13. The method for manufacturing a battery cell according to claim 1, wherein the electrode comprises electrode particles that are at least partially less than 300 microns in size and filled to have a pore volume of less than 50% of the total electrode volume.

14. It is a rechargeable battery cell, An electrode containing multiple particles, An ion exchange material formed at least partially by processing an n-mer coated electrode to polymerize the n-mer, wherein the processed ion exchange material is in contact with and surrounds at least a portion of the particles of the electrode, Rechargeable battery cells, including [specific components].

15. The rechargeable battery cell according to claim 14, wherein the electrode further comprises at least one of zinc, aluminum, magnesium, iron, lithium, and their respective oxides or salts.

16. The rechargeable battery cell according to claim 14, wherein the electrode further comprises a zinc (Zn)-containing anode.

17. The electrode is nickel hydroxide (Ni(OH) ２ ), nickel oxyhydroxide (NiOOH), manganese dioxide (MnO ２ The rechargeable battery cell according to claim 14, wherein the cathode comprises at least one of manganese oxide (MnO), iron salt (Fe(VI)), manganese salt (Mn(VI)), and permanganate (Mn(VII)).

18. The rechargeable battery cell according to claim 14, wherein the electrode comprises electrode particles that are at least partially less than 300 microns in size and filled to have a pore volume of less than 50% of the total electrode volume.

19. The rechargeable battery cell according to claim 14, wherein the ion exchange material further comprises an anion exchange material.

20. The rechargeable battery cell according to claim 14, wherein the ion exchange material further comprises a polymer material.

21. The rechargeable battery cell according to claim 14, wherein the ion exchange material further comprises a polymer material to which positively charged functional groups are bonded.

22. The rechargeable battery cell according to claim 14, further comprising a liquid alkaline electrolyte.

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