Rechargeable double-electrolyte zinc-air battery

Abstract

A rechargeable dual electrolyte zinc-air battery is disclosed that includes a zinc metal anode, an air suction cathode, an ion conducting membrane, and an acidic catholyte and an alkaline anolyte, where the acidic catholyte is an aqueous acidic solution containing an acid compatible polymer additive. Also disclosed is a method of forming the rechargeable dual electrolyte zinc-air battery, comprising the steps of providing a zinc anode, providing an air suction cathode, providing an alkaline anolyte and an acidic catholyte, where the acidic catholyte is an aqueous acidic solution containing an acid compatible polymer additive, and the alkaline anolyte and the acidic catholyte are separated via an ion conducting membrane. The invention also discloses an improvement method of the rechargeable double-electrolyte zinc-air battery.

Description

Invention Field

[0001] This invention relates to the field of batteries, and more specifically to a rechargeable dual-electrolyte zinc-air battery. Background Technology

[0002] Unlike conventional lithium-ion batteries, which face safety, cost, and environmental concerns due to material scarcity and toxicity, zinc is abundant and inexpensive, contributing to lower battery costs. Zinc is also a non-toxic and recyclable material, making zinc-air batteries a sustainable and environmentally friendly renewable energy solution. Furthermore, among various battery types, zinc-air batteries have a high theoretical energy density, allowing them to store more energy per unit weight. Additionally, zinc-air batteries are generally safer because they are less prone to overheating or explosion. Therefore, rechargeable zinc-air batteries are advantageous for lightweight and compact energy storage applications.

[0003] In this type of zinc battery, zinc metal is used as the anode, while oxygen from the air is reduced at the cathode. A major problem with current rechargeable zinc-air batteries is the formation of dendrites at the zinc anode. These dendrites grow with each cycle and eventually reach the opposite electrode, causing internal short circuits and battery failure, shortening the device's lifespan and durability. High-concentration alkaline solutions are typically used to ensure the reversibility of the zinc anode. However, these solutions inevitably cause corrosion and passivation of the zinc anode, promote parasitic hydrogen evolution reactions during charging, and form carbonates by absorbing CO2 from the air, clogging the active sites of the air cathode.

[0004] US Patent 9,252,616 B2 discloses a zinc-air battery with a low-weight and low-volume device for charging it. US Patent Application US 2020 / 0411825A1 discloses a dual-electrolyte electrochemical cell and system, which describes a battery assembly in which electrodes are positioned on their respective current collectors and separated therebetween.

[0005] The paper by Song et al., entitled “A Rechargeable Zn-Air Battery with High Energy Efficiency and Long Life Enabled by a Highly Water-Retentive Gel Electrolyte with Reaction Modifier” (DOI:10.1002 / adma.201908127), demonstrates an alkaline gel polymer electrolyte through multiple crosslinking of poly(vinyl alcohol) (PVA), poly(acrylic acid), and graphene oxide in an alkaline electrolyte and a KI modifier. This battery operates at 2 mA cm⁻¹. -2 The results show a low charging potential of 1.69V and a discharging potential of 1.24V, as well as a long cycle time of 200h. Huang et al. developed rechargeable zinc / nickel-cobalt batteries and zinc-air batteries using sodium polyacrylate hydrogel electrolytes, which are solid-state and possess high ionic conductivity and water retention. These batteries exhibited improved cycle performance. However, the voltage of these single-electrolyte batteries is significantly lower than that of lithium-ion batteries.

[0006] Zinc-air batteries with dual electrolytes instead of a single alkaline electrolyte would be advantageous, as this could significantly improve battery performance and lifespan. Summary of the Invention

[0007] This invention provides a rechargeable dual-electrolyte zinc-air battery with excellent overall performance. It significantly improves the voltage of the rechargeable zinc-air battery, inhibits dendrite formation, avoids corrosion passivation of the zinc anode and blockage of the active sites of the air cathode, thereby improving the battery's lifespan and durability.

[0008] This invention provides a rechargeable dual-electrolyte zinc-air battery, comprising:

[0009] Zinc metal anode,

[0010] Air is drawn into the cathode.

[0011] Ion-conducting membranes, and

[0012] Acidic cathode electrolyte and alkaline anolyte,

[0013] The acidic cathode electrolyte is an aqueous acidic solution containing an acid-compatible polymer additive.

[0014] The present invention also provides a method for forming the above-mentioned rechargeable dual-electrolyte zinc-air battery, comprising the following steps:

[0015] Provide zinc anodes,

[0016] Provides air intake cathode,

[0017] An alkaline anolyte and an acidic catholyte are provided, wherein the acidic catholyte is an aqueous acidic solution containing an acid-compatible polymer additive, and

[0018] The alkaline anolyte and the acidic catholyte are separated by an ion-conducting membrane.

[0019] This invention further provides an improved method for a rechargeable dual-electrolyte zinc-air battery, wherein the rechargeable dual-electrolyte zinc-air battery includes a zinc metal anode, an air-drawing cathode, an ion-conducting membrane, and an acidic cathode electrolyte and an alkaline anolyte, comprising:

[0020] An acid-compatible polymer additive is added to the acidic cathode electrolyte. Attached Figure Description

[0021] Figure 1 The structure of a dual-electrolyte zinc-air battery is shown.

[0022] Figure 2 The working principle of the dual-electrolyte zinc-air battery according to the present invention in the discharge (a) and charge (b) states is shown.

[0023] Figure 3 The following are shown: OCV (a) of a dual-electrolyte zinc-air battery using an acidic cathode electrolyte without / with acid-compatible polymer additives; electrochemical impedance spectroscopy (b) of a dual-electrolyte zinc-air battery using an acidic cathode electrolyte without acid-compatible polymer additives under OCV, charging, and discharging conditions; and electrochemical impedance spectroscopy (c) of a dual-electrolyte zinc-air battery using an acidic cathode electrolyte with acid-compatible polymer additives under OCV, charging, and discharging conditions.

[0024] Figure 4 The operating principle of a zinc-air battery using a single alkaline electrolyte and its performance at 0.1 mA cm⁻¹ are illustrated. -2 The galvanic discharge-charge curves are shown in (a); the galvanic discharge-charge curves of a dual-electrolyte zinc-air battery using an acidic cathode electrolyte without acid-compatible polymer additives at different current densities are shown in (b); and the galvanic discharge-charge curves of a dual-electrolyte zinc-air battery using an acidic cathode electrolyte containing acid-compatible polymer additives are shown in (c).

[0025] Figure 5A dual-electrolyte zinc-air battery is shown at 0.1 mA cm⁻¹ using an alkaline electrolyte containing an alkali-compatible polymer additive and an acidic cathode electrolyte containing an acid-compatible polymer additive. -2 The constant current discharge-charge curve is shown below.

[0026] Figure 6 The following are shown: the cathode cross-sectional morphology (a) of a dual-electrolyte zinc-air battery using an acidic cathode electrolyte containing an acid-compatible polymer additive; the elemental concentration distribution along the central axis of the cathode cross-section (b); and the elemental concentration on the overall cathode surface. Detailed Implementation

[0027] As used herein, unless otherwise expressly stated, expressions such as numerical values, ranges, contents, or percentages used in the specification and claims should be considered to vary in all cases according to the term "about," even if the term is not explicitly stated. Therefore, unless stated to the contrary, the numerical parameters listed in the specification and claims herein are approximate values ​​and may vary according to the performance desired by the invention.

[0028] Although the numerical ranges and parameters listed in this invention are approximate, the values ​​listed in the specific embodiments are recorded as accurately as possible. However, any value inherently possesses a certain degree of error. This error is a necessary consequence of the standard deviation derived from the corresponding measurement method.

[0029] Furthermore, it should be understood that any numerical range described herein is intended to include all subranges falling within it. For example, the range “1 to 10” is intended to include all subranges between the minimum value 1 and the maximum value 10, i.e., a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0030] In this application, unless otherwise expressly stated, the use of the singular includes the plural and the plural includes the singular. Furthermore, in this application, unless otherwise expressly stated, "or" is used to mean "and / or," even if "and / or" may be explicitly used in certain circumstances. Additionally, in this application, unless otherwise expressly stated, "a" or "an" is used to mean "at least one." For example, "a" polymer refers to any one or more of these substances. And, as those skilled in the art will recognize, features of one embodiment may be used in conjunction with other embodiments, even if not explicitly stated.

[0031] In this application, the terms “comprising,” “including,” “containing,” and similar terms mean including but not limited to, and do not exclude any variations or additions. Furthermore, although the present invention has described battery compositions and / or methods of formation, etc., using terms such as “comprising,” the batteries and / or methods of formation, etc., detailed herein may also be described as “consisting substantially of…” or “consisting of…”.

[0032] As described above, the present invention relates to a rechargeable dual-electrolyte zinc-air battery, comprising:

[0033] Zinc metal anode,

[0034] Air is drawn into the cathode.

[0035] Ion-conducting membranes, and

[0036] Acidic cathode electrolyte and alkaline anolyte,

[0037] The acidic cathode electrolyte is an aqueous acidic solution containing an acid-compatible polymer additive.

[0038] As used herein, “acidic” means a solution with a pH less than 7 at 25°C. As used herein, “alkaline” means a solution with a pH greater than 7 at 25°C. As used herein, “compatible” means that the polymer exists in a non-aggregated state in solution.

[0039] This invention improves the voltage of a zinc-air battery by using an alkaline anolyte and an acidic catholyte in a two-chamber battery, respectively; it utilizes an ion-conducting membrane to separate the anolyte and catholyte to avoid direct neutralization while allowing ion exchange during battery operation; and it employs suitable polymer additives to increase the water retention of the catholyte, suppress cathodic overflow, and help prevent zinc dendrite formation, thereby improving the overall battery performance.

[0040] Suitably, the acid-compatible polymer additive used in this invention may be selected from one or more of the following: polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyacrylamide (PAM), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyimide (PI), polyvinyl chloride (PVC), polypropylene (PP), sodium polyacrylate (PAANa), and any combination thereof. Suitably, the acid-compatible polymer additive may include polyethylene oxide (PEO).

[0041] Suitablely, the concentration of the acid-compatible polymer additive in the acidic cathode electrolyte can be 0.1-20 mg / mL. -1 For example, the concentration of the acid-compatible polymer additive in the acidic cathode electrolyte can be 0.1 mg / mL. -1Or higher, 1 mg / mL -1 Or higher, 2 mg / mL -1 Or higher, 3 mg / mL -1 Or higher, 4 mg / mL -1 Or higher, 5 mg / mL -1 Or higher, 6 mg / mL -1 Or higher, 7 mg / mL -1 Or higher, 8 mg / mL -1 Or higher, 9 mg / mL -1 Or higher, or 10 mg / mL -1 Or higher, and / or, 20 mg / mL -1 Or lower, 19 mg / mL -1 Or lower, 18 mg / mL -1 Or lower, 17 mg / mL -1 Or lower, 16 mg / mL -1 Or lower, 15 mg / mL -1 Or lower, 14 mg / mL -1 Or lower, 13 mg / mL -1 Or lower, 12 mg / mL -1 Or lower, or 11 mg / mL -1 Or lower. Suitably, the concentration of the acid-compatible polymer additive in the acidic cathode electrolyte can be 6-18 mg / mL. -1 7-16 mg / mL -1 8-14 mg / mL -1 10-12 mg / mL -1 , or within the range of any of the above values ​​as endpoints.

[0042] Suitably, the aqueous acidic solution used in this invention may include one or more of the following: sulfuric acid, hydrochloric acid, nitric acid, permanganic acid, perchloric acid, selenic acid, hydrobromic acid, hydroiodic acid, chloric acid, and any combination thereof. Suitably, the H+ of the aqueous acidic solution... + The concentration can be 0.1-3M. For example, the H+ of the aqueous acidic solution... +The concentration can be 0.1M or higher, 0.2M or higher, 0.3M or higher, 0.4M or higher, 0.5M or higher, 0.6M or higher, 0.7M or higher, 0.8M or higher, 0.9M or higher, 1M or higher, 1.1M or higher, 1.2M or higher, 1.3M or higher, 1.4M or higher, or 1.5M or higher, and / or 3M or lower, 2.9M or lower, 2.8M or lower, 2.7M or lower, 2.6M or lower, 2.5M or lower, 2.4M or lower, 2.3M or lower, 2.2M or lower, 2.1M or lower, 2M or lower, 1.9M or lower, 1.8M or lower, 1.7M or lower, or 1.6M or lower. Suitably, the H+ of the aqueous acidic solution... + The concentration can be 1-2M, 1.2-1.8M, 1.4-1.6M, or within any of the above values.

[0043] For example, the acidic cathode electrolyte suitable for use in the rechargeable dual-electrolyte zinc-air battery of the present invention can be an aqueous sulfuric acid solution containing an acid-compatible polymer additive, wherein the concentration of the sulfuric acid is 1-2 M. For example, the acid-compatible polymer additive may include polyethylene oxide (PEO), and the acidic cathode electrolyte can be an aqueous sulfuric acid solution containing polyethylene oxide (PEO). Suitably, the concentration of the polyethylene oxide (PEO) can be 10-12 mg / mL. -1 .

[0044] In some embodiments, the alkaline anolyte in the rechargeable dual-electrolyte zinc-air battery according to the present invention can be an aqueous alkaline solution. Suitably, the aqueous alkaline solution may include one or more of the following: lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, francium hydroxide, and any combination thereof. Suitably, the OH- of the aqueous alkaline solution... - The concentration is 3-8M. For example, the OH- of the aqueous alkaline solution... - The concentration can be 3M or higher, 3.2M or higher, 3.4M or higher, 3.6M or higher, 3.8M or higher, 4M or higher, 4.2M or higher, 4.4M or higher, 4.6M or higher, 4.8M or higher, 5M or higher, 5.2M or higher, 5.4M or higher, or 5.6M or higher, and / or 8M or lower, 7.8M or lower, 7.6M or lower, 7.4M or lower, 7.2M or lower, 7M or lower, 6.8M or lower, 6.6M or lower, 6.4M or lower, 6.2M or lower, 6M or lower, or 5.8M or lower. Suitably, the OH- of the aqueous alkaline solution... - The concentration can be 4-7M, 4.6-6.4M, 5-6M, or within any of the above values.

[0045] In some embodiments, the alkaline anolyte in the rechargeable dual-electrolyte zinc-air battery according to the present invention can be an aqueous alkaline solution containing an alkali-compatible polymer additive. During battery discharge, zinc ions at the anode are dissolved into the alkaline anolyte, and the polymer additive inhibits the mobility of zinc ions away from the anode surface, which is beneficial for suppressing the formation of zinc dendrites.

[0046] Suitablely, the aqueous alkaline solution may include one or more of the following: lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, francium hydroxide, and any combination thereof.

[0047] Suitablely, the alkali-compatible polymer additive may be selected from one or more of the following: sodium polyacrylate (PAANa), carboxymethyl cellulose (CMC), cellulose fibers, epoxy resin, and any combination thereof.

[0048] Suitablely, the OH- of the aqueous alkaline solution - The concentration is 3-8M. For example, the OH- of the aqueous alkaline solution... - The concentration can be 3M or higher, 3.2M or higher, 3.4M or higher, 3.6M or higher, 3.8M or higher, 4M or higher, 4.2M or higher, 4.4M or higher, 4.6M or higher, 4.8M or higher, 5M or higher, 5.2M or higher, 5.4M or higher, or 5.6M or higher, and / or 8M or lower, 7.8M or lower, 7.6M or lower, 7.4M or lower, 7.2M or lower, 7M or lower, 6.8M or lower, 6.6M or lower, 6.4M or lower, 6.2M or lower, 6M or lower, or 5.8M or lower. Suitably, the OH- of the aqueous alkaline solution... - The concentration can be 4-7M, 4.6-6.4M, 5-6M, or within any of the above values.

[0049] Suitablely, the concentration of the alkali-compatible polymer additive in the alkaline anolyte can be 1-20 mg / mL. -1 For example, the concentration of the alkali-compatible polymer additive in the alkaline anolyte can be 1 mg / mL. -1 Or higher, 2 mg / mL -1 Or higher, 3 mg / mL -1 Or higher, 4 mg / mL -1 Or higher, 5 mg / mL -1 Or higher, 6 mg / mL -1 Or higher, 7 mg / mL -1 Or higher, 8 mg / mL -1 Or higher, 9 mg / mL-1 Or higher, or 10 mg / mL -1 Or higher, and / or, 20 mg / mL -1 Or lower, 19 mg / mL -1 Or lower, 18 mg / mL -1 Or lower, 17 mg / mL -1 Or lower, 16 mg / mL -1 Or lower, 15 mg / mL -1 Or lower, 14 mg / mL -1 Or lower, 13 mg / mL -1 Or lower, 12 mg / mL -1 Or lower, or 11 mg / mL -1 Or lower. Suitably, the concentration of the alkali-compatible polymer additive in the alkaline anolyte can be 6-18 mg / mL. -1 7-16 mg / mL -1 8-14 mg / mL -1 10-12 mg / mL -1 , or within the range of any of the above values ​​as endpoints.

[0050] For example, the alkaline anolyte suitable for use in the rechargeable dual-electrolyte zinc-air battery of the present invention can be an aqueous solution of potassium hydroxide containing an alkali-compatible polymer additive, wherein the concentration of potassium hydroxide is 4-7 M. For example, the alkali-compatible polymer additive may include sodium polyacrylate (PAANa), and the alkaline anolyte can be an aqueous solution of potassium hydroxide containing sodium polyacrylate (PAANa). Suitably, the concentration of sodium polyacrylate (PAANa) can be 10-12 mg / mL. -1 .

[0051] In the rechargeable dual-electrolyte zinc-air battery according to the present invention, the ion-conducting membrane may include a perfluorosulfonic acid ion-exchange membrane and / or a non-fluorine ion-exchange membrane. The ion-conducting membrane can prevent the mixing and neutralization of the anolyte and catholyte, while simultaneously enabling ion exchange.

[0052] The ion-conducting membrane suitable for use in the rechargeable dual-electrolyte zinc-air battery according to the present invention may include, but is not limited to: Nafion 117 membrane, Nafion 115 membrane, Nafion 211 membrane, and any combination thereof.

[0053] In the rechargeable dual-electrolyte zinc-air battery according to the present invention, the zinc anode can be any zinc material suitable for zinc-air batteries. For example, the zinc anode can be a 99% pure zinc plate. In the rechargeable dual-electrolyte zinc-air battery according to the present invention, the air intake cathode can be any cathode material suitable for zinc-air batteries. For example, the air intake cathode can be commercially available carbon paper with Pt / C deposition.

[0054] The rechargeable dual-electrolyte zinc-air battery according to the present invention may further include an anode current collector and a cathode current collector. The cathode current collector may be made of a conductive and acid-resistant material. Suitably, the cathode current collector comprises silver foil, graphite foil, and / or titanium foil.

[0055] The rechargeable dual-electrolyte zinc-air battery according to the present invention may further include a battery support. The support may be placed at both ends of the battery and / or between components, and forms an electrolyte reservoir. Suitably, the support may include a poly(methyl methacrylate) (PMMA) plate.

[0056] The rechargeable dual-electrolyte zinc-air battery according to the present invention may further include a buffer pad. The buffer pad may be placed between battery components to prevent electrolyte leakage. Suitably, the buffer pad may include a silicone rubber buffer pad.

[0057] The rechargeable dual-electrolyte zinc-air battery according to the present invention may also include other auxiliary components, such as, not mentioned above, encapsulation, thermal management, battery balancing and / or other such components.

[0058] The present invention also relates to a method for forming the above-mentioned rechargeable dual-electrolyte zinc-air battery, comprising the following steps:

[0059] Provide zinc anodes,

[0060] Provides air intake cathode,

[0061] An alkaline anolyte and an acidic catholyte are provided, wherein the acidic catholyte is an aqueous acidic solution containing an acid-compatible polymer additive, and

[0062] The alkaline anolyte and the acidic catholyte are separated by an ion-conducting membrane.

[0063] The forming method may further include:

[0064] Connect the anode to the anode current collector.

[0065] The forming method may further include:

[0066] The cathode is connected to a cathode current collector, wherein the cathode current collector comprises silver foil, graphite foil, and / or titanium foil.

[0067] Suitablely, the rechargeable dual-electrolyte zinc-air battery according to the present invention can be assembled into a layered structure. Therefore, the formation method may further include:

[0068] The battery is assembled into a layered structure, and the components are housed in a poly(methyl methacrylate) (PMMA) plate.

[0069] Insert the silicone rubber sheet between every two PMMA plates.

[0070] In this document, the term "component" may refer to an anode, cathode, electrolyte, and / or ion-conducting membrane, etc.

[0071] The rechargeable dual-electrolyte zinc-air battery according to the present invention can be constructed as follows: Figure 1 As shown in the figure, the battery sequentially includes: a zinc anode, an alkaline anolyte, an ion-conducting membrane, an acidic cathode electrolyte, and an air-drawing cathode, with the ion-conducting membrane located at the center of the battery assembly. Polymethyl methacrylate (PMMA) plates are cut into a designed pattern to serve as supports for the electrodes. The zinc anode and the air-drawing cathode are respectively placed on the electrode supports and located on either side of the ion-conducting membrane. Two chambers constructed from the PMMA plates serve as electrolyte reservoirs for the alkaline anolyte and the acidic cathode electrolyte, respectively. The alkaline anolyte reservoir is placed between the zinc anode and the ion-conducting membrane. The acidic cathode electrolyte reservoir is placed between the ion-conducting membrane and the air-drawing cathode, with the cathode having a catalyst layer facing the electrolyte. A patterned silicone rubber sheet is placed between every two PMMA plates as a buffer to prevent leakage of the aqueous electrolyte. The zinc anode is a cut square with a long wire on one side serving as an anolyte current collector. The cathode is a cut square using a thin layer of conductive and acid-resistant material as a cathode current collector.

[0072] In the rechargeable dual-electrolyte zinc-air battery according to the present invention, air can be drawn in through the porous back of the carbon paper. As the battery undergoes cycling, the zinc anode undergoes metal stripping and plating, while oxygen is reduced and formed during battery discharge and charging, respectively.

[0073] Figure 2The operating principle of the rechargeable dual-electrolyte zinc-air battery according to the present invention in the discharge (a) and charge (b) states is illustrated. During the battery discharge process, zinc ions are dissolved in the alkaline anolyte, and their mobility away from the anode surface is inhibited by suitable polymer additives in the anolyte. Simultaneously, oxygen from the ambient air is drawn in from the back of the carbon paper at the cathode and reduced at the water-air-electrode interface. The polymer in the cathode electrolyte hinders the unwanted cation transport from the bulk solution to the cathode surface, avoiding blockage of active sites. Furthermore, the polymer chains are able to absorb water and significantly extend the time before cathode overflow occurs, allowing the zinc-air battery to operate at high performance for a longer period.

[0074] Because zinc ions are confined to the region near the anode, they can readily deposit on the anode during battery charging with minimal zinc loss. Simultaneously, an oxygen generation reaction (OER) occurs at the cathode. Since water is retained by the polymer and the active sites on the cathode surface remain clean, the OER of the bulk cathode electrolyte is effective, resulting in reduced overvoltage and minimized voltage gap between the two electrodes.

[0075] Therefore, the rechargeable dual-electrolyte zinc-air battery according to the present invention has excellent overall performance, and compared with the zinc-air batteries of the prior art (e.g., single alkaline electrolyte zinc-air batteries, dual electrolyte zinc-air batteries without polymer additives), it has significantly improved battery stability, lifespan and durability.

[0076] This invention also relates to an improved method for a rechargeable dual-electrolyte zinc-air battery, wherein the rechargeable dual-electrolyte zinc-air battery includes a zinc metal anode, an air-drawing cathode, an ion-conducting membrane, and an acidic cathode electrolyte and an alkaline anolyte, comprising:

[0077] An acid-compatible polymer additive is added to the acidic cathode electrolyte.

[0078] Suitablely, the acid-compatible polymer additive may be selected from one or more of the following: polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyacrylamide (PAM), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyimide (PI), polyvinyl chloride (PVC), polypropylene (PP), sodium polyacrylate (PAANa), and any combination thereof.

[0079] Suitablely, the concentration of the acid-compatible polymer additive in the acidic cathode electrolyte can be 0.1-20 mg / mL. -1 For example, the concentration of the acid-compatible polymer additive in the acidic cathode electrolyte can be 0.1 mg / mL. -1 Or higher, 1 mg / mL-1 Or higher, 2 mg / mL -1 Or higher, 3 mg / mL -1 Or higher, 4 mg / mL -1 Or higher, 5 mg / mL -1 Or higher, 6 mg / mL -1 Or higher, 7 mg / mL -1 Or higher, 8 mg / mL -1 Or higher, 9 mg / mL -1 Or higher, or 10 mg / mL -1 Or higher, and / or, 20 mg / mL -1 Or lower, 19 mg / mL -1 Or lower, 18 mg / mL -1 Or lower, 17 mg / mL -1 Or lower, 16 mg / mL -1 Or lower, 15 mg / mL -1 Or lower, 14 mg / mL -1 Or lower, 13 mg / mL -1 Or lower, 12 mg / mL -1 Or lower, or 11 mg / mL -1 Or even lower. Suitably, the concentration of the acid-compatible polymer additive in the acidic cathode electrolyte can be 6-18 mg / mL. -1 7-16 mg / mL -1 8-14 mg / mL -1 10-12 mg / mL -1 , or within the range of any of the above values ​​as endpoints.

[0080] Suitablely, the improved method may further include:

[0081] An additive containing an alkali-compatible polymer is added to the alkaline anolyte.

[0082] Suitablely, the alkali-compatible polymer additive may be selected from one or more of the following: sodium polyacrylate (PAANa), carboxymethyl cellulose (CMC), cellulose fibers, epoxy resin, and any combination thereof.

[0083] Suitablely, the concentration of the alkali-compatible polymer additive in the alkaline anolyte can be 1-20 mg / mL. -1 For example, the concentration of the alkali-compatible polymer additive in the alkaline anolyte can be 1 mg / mL. -1 Or higher, 2 mg / mL -1 Or higher, 3 mg / mL -1 Or higher, 4 mg / mL -1Or higher, 5 mg / mL -1 Or higher, 6 mg / mL -1 Or higher, 7 mg / mL -1 Or higher, 8 mg / mL -1 Or higher, 9 mg / mL -1 Or higher, or 10 mg / mL -1 Or higher, and / or, 20 mg / mL -1 Or lower, 19 mg / mL -1 Or lower, 18 mg / mL -1 Or lower, 17 mg / mL -1 Or lower, 16 mg / mL -1 Or lower, 15 mg / mL -1 Or lower, 14 mg / mL -1 Or lower, 13 mg / mL -1 Or lower, 12 mg / mL -1 Or lower, or 11 mg / mL -1 Or lower. Suitably, the concentration of the alkali-compatible polymer additive in the alkaline anolyte can be 6-18 mg / mL. -1 7-16 mg / mL -1 8-14 mg / mL -1 10-12 mg / mL -1 , or within the range of any of the above values ​​as endpoints.

[0084] The following examples are intended to illustrate certain embodiments of the invention, rather than to demonstrate the full scope of the invention.

[0085] Example

[0086] The performance of the rechargeable dual-electrolyte zinc-air battery according to the present invention was characterized and compared with that of prior art zinc-air batteries:

[0087] 1. Open circuit voltage

[0088] Reference Figure 1 A rechargeable dual-electrolyte zinc-air battery was assembled. The zinc anode was a 99% pure zinc plate cut into 1.4cm x 1.4cm squares, with a long wire on one side serving as the anode current collector. The air intake cathode was a commercially available carbon paper with Pt / C deposition, cut into 1.4cm x 1.4cm squares, with a thin layer of silver foil used as the cathode current collector. The anode electrolyte was a 6M potassium hydroxide solution, and the cathode electrolyte was either a 1.5M sulfuric acid aqueous solution or a solution containing 10 mg / mL of potassium hydroxide. -1 A 1.5M aqueous solution of PEO in sulfuric acid was used. The open-circuit voltage (OCV) of the battery over time was measured, and the results are as follows. Figure 3 As shown in (a).

[0089] As can be seen, for batteries containing PEO polymer, the OCV remains stable at 2.4V from 0 to 4000 seconds; while for batteries without polymer, the OCV shows slight fluctuations around 2.1V. This demonstrates the significant advantage of polymer additives in the cathode electrolyte in maintaining a more stable electrolyte-gas-electrode interface.

[0090] 2. Electrochemical impedance spectroscopy

[0091] Reference Figure 1 A rechargeable dual-electrolyte zinc-air battery was assembled. The zinc anode was a 99% pure zinc plate cut into 1.4cm x 1.4cm squares, with a long wire on one side serving as the anode current collector. The air intake cathode was a commercially available carbon paper with Pt / C deposition, cut into 1.4cm x 1.4cm squares, with a thin layer of silver foil used as the cathode current collector. The anode electrolyte was a 6M potassium hydroxide solution, and the cathode electrolyte was either a 1.5M sulfuric acid aqueous solution or a solution containing 10 mg / mL of potassium hydroxide. -1 A 1.5M aqueous solution of PEO in sulfuric acid was used. Electrochemical impedance spectroscopy (EIS) of the battery was tested under OCV, charge, and discharge conditions, and the results are as follows: Figure 3 As shown in (b) and (c). For battery 3(b) without polymer and battery 3(c) with polymer, the state of charge was tested at 2.8V and the state of discharge was tested at 1.8V.

[0092] The slope of the low-frequency region in the Nyquist plot represents the mass transfer rate of the reactants; a steeper slope indicates slower mass transfer [1]. The intersection of the Nyquist plot and the horizontal axis represents the ohmic resistance of the target device. The first circle in the Nyquist plot represents the kinetics of the target electrochemical reaction [2, 3]. Figure 3 (b) It can be seen that the ohmic resistance of the zinc-air battery increases with battery operation, and it exhibits a higher ohmic resistance in the charging state compared with the discharging state.

[0093] Under OCV conditions, the polymer-added battery exhibited a similar ohmic resistance to the unpolymer-added battery. Meanwhile, with the presence of PEO additives in the cathode electrolyte, the battery resistance decreased during the charging state. Although the ohmic resistance increased slightly during the discharging state, the impedance spectrum showed a smaller semicircle, indicating higher electrode reaction kinetics. This enhanced reaction kinetics is likely due to the increased exposure of active sites on the cathode as the polymer prevents unwanted ion adsorption on the electrode. Overall, the higher kinetics of the electrochemical reactions at the electrode lead to a higher battery operating voltage, allowing for higher power output.

[0094] 3. Constant current discharge-charge curve

[0095] Assemble a single alkaline electrolyte zinc-air battery. The zinc anode is a 99% pure zinc plate cut into 1.4cm x 1.4cm squares, with a long wire on one side serving as the anode current collector. The air intake cathode is a commercially available carbon paper with Pt / C deposition, cut into 1.4cm x 1.4cm squares, with a thin layer of silver foil used as the cathode current collector. The electrolyte is a 6M potassium hydroxide solution.

[0096] Reference Figure 1 A rechargeable dual-electrolyte zinc-air battery was assembled. The zinc anode was a 99% pure zinc plate cut into 1.4cm x 1.4cm squares, with a long wire on one side serving as the anode current collector. The air intake cathode was a commercially available carbon paper with Pt / C deposition, cut into 1.4cm x 1.4cm squares, using a thin layer of silver foil as the cathode current collector. The anode electrolyte was a 6M potassium hydroxide solution or a solution containing 10 mg / mL... -1 The 6M potassium hydroxide solution of PAANa and the cathode electrolyte were 1.5M sulfuric acid aqueous solution or solution containing 10 mg / mL. -1 1.5M sulfuric acid aqueous solution of PEO.

[0097] The battery was tested under constant current discharge-charge curves, and the results are as follows: Figure 4 (a), (b) and (c) and Figure 5 As shown.

[0098] The OCV of a single alkaline electrolyte zinc-air battery is around 1.6V, and its value is around 0.1mA cm⁻¹. -2 The charging and discharging curves are as follows Figure 4 As shown in (a), the discharge voltage stabilizes at around 1.43V, while the charging voltage plateaus at 1.5V. This performance is similar to that reported in the literature.

[0099] exist Figure 4 In (b), 6M KOH was used as the alkaline anolyte, and 1.5M H2SO4 was used as the acidic catholyte, at 0.2 mA cm⁻¹. -2 The charging and discharging platforms stabilized at 2.29V and 2.0V, respectively. The voltage gap between the two electrodes increased with increasing operating current density.

[0100] exist Figure 4In (c), 6M KOH was used as the alkaline anolyte, and 1.5M H₂SO₄ with added PEO was used as the acidic catholyte. This polymer-added battery was charged and discharged at various current densities, and under the same operating conditions, it showed a stable charge-discharge curve with a slightly larger voltage gap compared to its polymer-free counterpart. The increase in voltage gap is mainly due to ohmic losses. Impressively, the battery with the polymer additive showed higher charge and discharge voltages. This indicates that polymer additives in the catholyte are beneficial for improving the performance of rechargeable zinc-air batteries.

[0101] exist Figure 5 In the middle, 6M KOH and add 10mg mL -1 Polymer PAANa additive is used as the alkaline anolyte, and 1.5M H2SO4 with added PEO is used as the acidic catholyte. At 0.1 mA cm⁻¹ -2 The charging voltage decreases during charging and discharging while the discharging voltage remains basically unchanged, indicating that the anolyte additive can alleviate the overpotential caused by dendrites on the negative electrode.

[0102] 4. Cathode surface morphology and elemental analysis

[0103] The cathode surface morphology and elemental analysis were performed on the dual-electrolyte zinc-air battery using a cathode electrolyte containing an acid-compatible polymer additive, which had passed the above performance tests. The results are as follows: Figure 6 As shown in (a), (b) and (c).

[0104] Depend on Figure 6 (a) It is evident that the polymer forms a thin layer covering the electrode surface while maintaining ion transport. Along Figure 6 The element distribution along the transverse axis of the cathode cross-section in (a) is... Figure 6 As shown in (b), the oxygen content in the polymer layer covering the cathode is maintained at a relatively high level. SEM images of arbitrary regions on the cathode surface are shown below. Figure 6 As shown in (c), the oxygen concentration is approximately 31 wt%, indicating a uniform polymer distribution. The inset shows the morphology of the cathode front surface, where the polymer forms a uniform network covering the catalyst particles. Figure 6 (b) and Figure 6 Consistent results in (c) demonstrate that a polymer layer is formed on the electrode surface to help retain water and enhance battery performance.

[0105] Many equivalents of the particular embodiments of the invention described herein will be recognized or identified by those skilled in the art using only conventional experiments. Such equivalents are intended to be covered by the appended claims.

[0106] All publications, patents and patent applications mentioned in this specification are incorporated herein by reference in their entirety as if each individual publication, patent or patent application were specifically and individually incorporated by reference in its entirety.

[0107] References and discussions in this document should not be construed as an admission that these are prior art of the invention.

[0108] References

[0109] References cited in this application are incorporated herein by reference in their entirety, as follows:

[0110] [1] Zhang, Sheng S., Kang Xu, and TRJow. "EIS study on the formation of solid electrolyte interface in Li-ion battery." Electrochimica acta 51.8-9(2006):1636-1640.

[0111] [2]Dokko, K., et al. "Kinetic characterization of single particles ofLiCoO2 by AC impedance and potential step methods." Journal of the Electrochemical Society 148.5(2001):A422.

[0112] [3] Chen, Linlin, and Andrzej Lasia. "Study of the kinetics of hydrogenevolution reaction on nickel-zinc powder electrodes." Journal of the Electrochemical Society 139.11(1992):3214.

Claims

1. A rechargeable dual-electrolyte zinc-air battery, comprising: Zinc metal anode, Air is drawn into the cathode. Ion-conducting membranes, and Acidic cathode electrolyte and alkaline anolyte, The acidic cathode electrolyte is an aqueous acidic solution containing an acid-compatible polymer additive.

2. The rechargeable dual-electrolyte zinc-air battery of claim 1, wherein the acid-compatible polymer additive is selected from one or more of the following: polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyacrylamide (PAM), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyimide (PI), polyvinyl chloride (PVC), polypropylene (PP), sodium polyacrylate (PAANa), and any combination thereof.

3. The rechargeable dual-electrolyte zinc-air battery as described in claim 1 or 2, wherein the concentration of the acid-compatible polymer additive in the acidic cathode electrolyte is 0.1-20 mg / mL. -1 .

4. The rechargeable dual-electrolyte zinc-air battery according to any one of claims 1-3, wherein the alkaline anolyte is an aqueous alkaline solution containing an alkali-compatible polymer additive.

5. The rechargeable dual-electrolyte zinc-air battery of claim 4, wherein the alkali-compatible polymer additive is selected from one or more of the following: sodium polyacrylate (PAANa), carboxymethyl cellulose (CMC), cellulose fibers, epoxy resin, and any combination thereof.

6. The rechargeable dual-electrolyte zinc-air battery as described in claim 4 or 5, wherein the concentration of the alkali-compatible polymer additive in the alkaline anolyte is 1-20 mg / mL. -1 .

7. The rechargeable dual-electrolyte zinc-air battery according to any one of claims 1-6, wherein the ion-conducting membrane comprises a perfluorosulfonic acid ion exchange membrane and / or a non-fluorine ion exchange membrane.

8. The rechargeable dual-electrolyte zinc-air battery of claim 7, wherein the perfluorosulfonic acid ion exchange membrane is selected from one or more of the following: Nafion 117 membrane, Nafion 115 membrane, Nafion 211 membrane, and any combination thereof.

9. The rechargeable dual-electrolyte zinc-air battery according to any one of claims 1-8, wherein the aqueous acidic solution comprises one or more of the following: sulfuric acid, hydrochloric acid, nitric acid, permanganic acid, perchloric acid, selenic acid, hydrobromic acid, hydroiodic acid, chloric acid, and any combination thereof.

10. The rechargeable dual-electrolyte zinc-air battery according to any one of claims 1-9, wherein the aqueous acidic solution contains H... + The concentration is 0.1-3M.

11. The rechargeable dual-electrolyte zinc-air battery according to any one of claims 4-10, wherein the aqueous alkaline solution comprises one or more of the following: lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, francium hydroxide, and any combination thereof.

12. The rechargeable dual-electrolyte zinc-air battery according to any one of claims 4-11, wherein the OH- of the aqueous alkaline solution... - The concentration is 3-8M.

13. A method for forming a rechargeable dual-electrolyte zinc-air battery as described in any one of claims 1-12, comprising the following steps: Provide zinc anodes, Provides air intake cathode, An alkaline anolyte and an acidic catholyte are provided, wherein the acidic catholyte is an aqueous acidic solution containing an acid-compatible polymer additive, and The alkaline anolyte and the acidic catholyte are separated by an ion-conducting membrane.

14. The forming method as described in claim 13, further comprising: The cathode is connected to a cathode current collector, wherein the cathode current collector comprises silver foil, graphite foil, and / or titanium foil.

15. The forming method as described in claim 13 or 14, further comprising: The battery is assembled into a layered structure, and the components are housed in a poly(methyl methacrylate) (PMMA) plate. Insert the silicone rubber sheet between every two PMMA plates.

16. The forming method according to any one of claims 13-15, wherein the cathode comprises carbon paper with Pt / C deposition.

17. An improved method for a rechargeable dual-electrolyte zinc-air battery, the rechargeable dual-electrolyte zinc-air battery comprising a zinc metal anode, an air-drawing cathode, an ion-conducting membrane, and an acidic cathode electrolyte and an alkaline anolyte, comprising: Add acid-compatible polymer additives to the acidic cathode electrolyte.

18. The improved method of claim 17, wherein the acid-compatible polymer additive is selected from one or more of the following: polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyacrylamide (PAM), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyimide (PI), polyvinyl chloride (PVC), polypropylene (PP), sodium polyacrylate (PAANa), and any combination thereof.

19. The improved method of claim 17 or 18, wherein the concentration of the acid-compatible polymer additive in the acidic cathode electrolyte is 0.1-20 mg / mL. -1 .

20. The improved method according to any one of claims 17-19, further comprising: An alkali-compatible polymer additive is added to the alkaline anolyte.

21. The improved method of claim 20, wherein the alkali-compatible polymer additive is selected from one or more of the following: sodium polyacrylate (PAANa), carboxymethyl cellulose (CMC), cellulose fibers, epoxy resin, and any combination thereof.

22. The improved method according to claim 20 or 21, wherein the concentration of the alkali-compatible polymer additive in the alkaline anolyte is 1-20 mg / mL. -1 .

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