An alkaline zinc-based battery and a method of making and using the same

Abstract

The application relates to a kind of alkaline zinc-based batteries and its preparation method and application, and the alkaline zinc-based battery includes zinc negative material, positive material and alkaline electrolyte, wherein the zinc negative material includes zinc negative pole and the second metal electric field shielding layer constructed on its two sides, the zinc negative pole is selected from any one of zinc metal or zinc alloy foil, sheet, board, the second metal electric field shielding layer is the metal material of weak reactivity than zinc.Compared with prior art, in the application, faraday cage type space can be formed between zinc negative pole and the second metal electric field shielding layer, can shield external electric field, significantly slow down the formation of zinc oxide on the surface of zinc negative pole, realize the uniform stripping of zinc, improve the problem that zinc negative pole is seriously passivated in alkaline system, improve the utilization rate and energy density of zinc negative pole in alkaline primary battery, improve long-term cycle stability and service life in alkaline secondary battery.

Description

Technical Field

[0001] This invention relates to the field of alkaline zinc-based battery technology, and in particular to an alkaline zinc-based battery, its preparation method, and its application. Background Technology

[0002] The escalating challenges of energy shortages and environmental pollution are driving profound changes in clean and renewable energy technologies worldwide. Developing advanced electrochemical energy storage devices is a crucial approach to addressing environmental and energy issues. While lithium-ion batteries have garnered significant attention due to their widespread market applications, their high cost, reliance on rare metal resources, and potential safety hazards such as flammability and explosiveness limit their further application. Therefore, developing low-cost, highly safe new energy storage technologies to replace or supplement existing systems and promoting innovation and development in energy storage technologies is imperative.

[0003] Zinc-based batteries possess advantages such as high theoretical capacity, abundant resources, and environmental friendliness, making them a promising candidate for storing intermittent renewable energy. In recent years, an increasing number of researchers have dedicated themselves to developing high-performance zinc-based batteries. Among various zinc-based batteries, alkaline zinc-based batteries exhibit superior performance, including high theoretical capacity and high specific energy. However, in alkaline batteries, the passivation, side reactions, and dendrite formation problems at the zinc anode are more severe than in neutral-acidic systems. Specifically, the passivation problem at the zinc anode leads to lower zinc anode utilization, significantly reducing the energy density of alkaline zinc-based batteries. Furthermore, the passivated zinc anode surface severely negatively impacts cycle reversibility, limiting the widespread application of alkaline zinc-based batteries. However, compared to the progress made in zinc deposition processes, the mitigation of passivation during zinc dissolution remains largely undiscussed and lacks insight. Although research has been conducted on fabricating zinc oxide anodes with zinc metal and complex three-dimensional structures, the increase in electrode volume and larger surface area exacerbates passivation, while additional conductive agents lead to the loss of active materials. Therefore, developing a zinc anode material that can effectively prevent zinc anode passivation in alkaline electrolyte is crucial for achieving high zinc utilization and uniform stripping, and the development of such a material is of great significance.

[0004] CN115548282A discloses an alkaline secondary battery anode material, its preparation method, and its application. This zinc anode material is a ZnO / ZnS / C composite material or a metal-doped ZnO / ZnS / C composite material. This novel alkaline secondary battery anode material can effectively reduce the deformation of the zinc anode, suppress the hydrogen evolution reaction and passivation of zinc dendrites, improve the stability of the zinc anode in alkaline solutions, and increase the cycle life of alkaline secondary batteries. However, its preparation method is complex, requires precise processes, and does not solve the fundamental problem of passivation of the zinc anode in alkaline systems.

[0005] CN106887581A discloses a zinc electrode material and its preparation and application. This electrode material is microscopically composed of core-shell structured micro / nanoparticles. It has a zinc core and a second metal (one or more alloys of iron, tin, lead, copper, silver, platinum, gold, indium, bismuth, thallium, gallium, and cadmium) as its shell. The second metal shell surrounds the zinc core, and there are voids between the zinc core and the second metal shell. This zinc electrode material effectively improves the cycle stability of the battery by controlling the dissolution of zinc oxide in the electrolyte to suppress hydrogen evolution. However, its reaction conditions are strict, the process is complex, and its effect on suppressing passivation of the zinc negative electrode surface is poor.

[0006] Therefore, developing an alkaline zinc-based battery and zinc anode material with a simple and feasible preparation method that can effectively suppress passivation of the zinc anode surface is of great practical significance. Summary of the Invention

[0007] The purpose of this invention is to provide an alkaline zinc-based battery, its preparation method, and its application, which can effectively suppress the problem of severe passivation caused by the formation of zinc oxide on the surface of the zinc anode in the alkaline electrolyte.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] On one hand, the present invention provides an alkaline zinc-based battery, comprising a zinc anode material, a cathode material and an alkaline electrolyte, wherein the zinc anode material comprises a zinc anode and a second metal electric field shielding layer constructed on both sides thereof.

[0010] Preferably, the alkaline zinc-based battery includes a zinc / air battery, a zinc / nickel battery, a zinc / silver battery, and a zinc / manganese battery.

[0011] Preferably, the alkaline electrolyte comprises a mixed solution of potassium hydroxide and zinc salt.

[0012] More preferably, in the mixed solution, the concentration of potassium hydroxide is 1-12 mol / L and the concentration of zinc salt is 0-0.2 mol / L.

[0013] More preferably, the zinc salt is one or more of zinc acetate, zinc chloride, and zinc oxide.

[0014] Preferably, the zinc negative electrode is selected from any one of zinc metal or zinc alloy foil, sheet, or plate.

[0015] Preferably, the second metal electric field shielding layer is a metal material with lower reactivity than zinc.

[0016] More preferably, the metal material with lower reactivity than zinc includes iron, copper, bismuth, tin, titanium, lead, silver, etc.

[0017] Preferably, the thickness of the second metal electric field shielding layer is 5-30 μm.

[0018] Preferably, the construction method of the second metal electric field shielding layer includes chemical plating, electroplating, and drop coating.

[0019] Secondly, the present invention also provides a method for preparing the above-mentioned alkaline zinc-based battery, which includes the following steps when constructing a second metal electric field shielding layer on the zinc negative electrode by chemical plating:

[0020] S1: Ultrasonic treatment of zinc metal foil or zinc alloy foil to obtain treated zinc sheets;

[0021] S2: Dissolve and stir the second metal salt, which is less reactive than zinc, to obtain a suspension of the second metal salt. Let it stand, separate, and take the clear and transparent solution as the soluble solution of the second metal salt.

[0022] S3: Place the treated zinc sheet obtained in step S1 into a soluble solution of the second metal salt obtained in step S2, construct a second metal electric field shielding layer on both sides of the zinc sheet by chemical plating, and clean it to obtain the zinc negative electrode material.

[0023] Preferably, in step S1, the ultrasonic treatment is performed at room temperature.

[0024] Preferably, in step S2, the concentration of the second metal ion in the second metal salt suspension is 0.01-2 mol / L.

[0025] Preferably, in step S2, the solvent in the soluble solution of the second metal salt is selected from one or more of water, ethanol, ethylene glycol, acetone, and glycerol.

[0026] Preferably, in step S2, the anion in the second metal salt is selected from one or more of chloride ions, sulfate ions, nitrate ions, and phosphate ions.

[0027] In steps S2 and S3, the time for chemical plating is 1-10 minutes.

[0028] Thirdly, the present invention also provides an application of the above-mentioned alkaline zinc-based battery in hearing aid batteries, automotive power, and mobile power.

[0029] In existing technologies, most methods for controlling the construction of a metal protective layer on the surface of the zinc anode target the behavior of the zinc anode in moderately acidic systems. In moderately acidic systems such as zinc sulfate electrolyte, the half-reaction equation for zinc is:

[0030] Zn-2e - →Zn 2+

[0031] In an alkaline system, the reaction equation for zinc is:

[0032] Zn-2e - +4OH - →Zn(OH)4 2-

[0033] The chemical reactions occurring at the zinc anode in acidic and alkaline systems are completely different, resulting in different ions. Passivation is not an issue in acidic zinc-ion battery systems. In alkaline systems, the solubility of zincate ions in the electrolyte is limited. When the concentration reaches a certain level, supersaturation occurs, leading to precipitation and the formation of an inert zinc oxide passivation layer on the zinc anode surface. This increases the dissolution overpotential, making dissolution difficult. At a certain overpotential, a solid-state precipitation reaction occurs, forming a dense zinc oxide passivation layer, preventing further dissolution. Most current research focuses on regulating the deposition process of zinc anodes in acidic systems, while this invention focuses on the passivation problem during zinc dissolution. Passivation of the zinc anode is directly caused by the electric field on the electrode surface. The second metal electric field shielding layer and its construction method in the alkaline zinc-based battery provided by this invention can effectively suppress the severe passivation problem caused by zinc oxide formation on the zinc anode surface in alkaline electrolytes.

[0034] Current research on the dissolution process of zinc anodes in alkaline systems is limited, and the passivation of zinc in alkaline systems has not received sufficient attention. Current modifications to zinc anodes in alkaline systems mainly involve 3D structural design, construction of interface protective layers, and zinc oxide structural modification. While 3D structural design reduces current density by increasing surface area, it inevitably exacerbates passivation. Interface protective layers, on the other hand, can not only regulate the electric field but also reduce the contact between the electrolyte and the electrode, suppressing side reactions. The second metal electric field shielding layer of the zinc anode in the alkaline zinc-based battery of this invention does not require complex fabrication processes, is simple and efficient to operate, has low requirements for experimental equipment and materials, and the prepared second metal electric field shielding layer is relatively uniform and flat, exhibiting strong reversibility.

[0035] This invention proposes an alkaline zinc-based battery in which a second metal electric field shielding layer is constructed on the surface of the zinc anode, exhibiting a Faraday cage structure at the microscopic level. A Faraday cage space is formed between the zinc anode and the second metal electric field shielding layer. This Faraday cage space can shield the external electric field, ensuring that the dissolution of the zinc anode at the interface is primarily spontaneous, while simultaneously promoting the mass transfer process of hydroxide ions, thus preventing capacity loss and waste of the zinc anode.

[0036] This invention proposes a concept for suppressing zinc anode passivation in alkaline systems by adjusting the electric field, and constructs a second metal electric field shielding layer for the zinc anode. Extensive experiments in this invention have verified that the second metal electric field shielding layer effectively shields the external electric field during zinc stripping, suppressing zincate aggregation caused by the electric field at the zinc anode interface and significantly slowing down the formation of zinc oxide on the zinc anode surface. Compared with existing technologies, this second metal electric field shielding layer based on the Faraday electric field shielding effect achieves uniform zinc stripping, improves the problem of severe passivation of the zinc anode in alkaline systems, greatly enhances the utilization rate and energy density of the zinc anode in alkaline primary batteries, and significantly improves the long-term cycle stability and service life in alkaline secondary batteries.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The present invention provides an alkaline zinc-based battery, wherein the zinc anode material includes a zinc anode and a second metal electric field shielding layer constructed on both sides thereof. The construction of the second metal electric field shielding layer can effectively suppress the problem of severe passivation caused by the formation of zinc oxide on the surface of the zinc anode in the alkaline electrolyte.

[0039] (2) The second metal electric field shielding layer constructed on the surface of the zinc anode in this invention can effectively suppress the aggregation of zincate caused by the electric field at the zinc anode interface, significantly slow down the formation of zinc oxide on the surface of the zinc anode, realize the uniform stripping of zinc, and improve the problem of severe passivation of the zinc anode in the alkaline system.

[0040] (3) In the zinc anode material of the present invention, a Faraday cage space can be formed between the zinc anode and the second metal electric field shielding layer, which can shield the external electric field, so that the dissolution of the zinc anode at the interface is mainly spontaneous dissolution, while promoting the mass transfer process of hydroxide ions, and avoiding the loss and waste of the zinc anode capacity.

[0041] (4) The present invention regulates the uniform stripping of zinc by means of the electric field shielding effect of the second metal electric field shielding layer during the stripping process of zinc negative electrode, thereby achieving high capacity, high energy density discharge and long-term cycle stability.

[0042] (5) The alkaline zinc-based battery provided by the present invention has a simple preparation process and uses low-toxicity and non-toxic reagents. The aqueous solution also meets the requirements of green environmental protection and low energy consumption. Attached Figure Description

[0043] Figure 1 This is a scanning electron microscope image of Embodiment 1 of the present invention.

[0044] Figure 2 The discharge curves of the symmetrical batteries in Example 2 and Comparative Example 2 of this invention are shown in the electrolyte of a mixed solution of 6 mol / L potassium hydroxide and 0.2 mol / L zinc acetate.

[0045] Figure 3 The above are charge-discharge cycle curves of the symmetrical batteries in Embodiment 2 and Comparative Example 2 of the present invention.

[0046] Figure 4 The power density discharge curves of the zinc-air batteries in Example 3 and Comparative Example 3 of this invention are shown. Detailed Implementation

[0047] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0048] Unless otherwise specified, the reagents, methods, instruments, and equipment used in this invention are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0049] Example 1

[0050] This embodiment provides a zinc anode material for an alkaline zinc-based battery. The zinc anode material includes a zinc anode and a second metal electric field shielding layer constructed on both sides thereon. The second metal electric field shielding layer on the zinc anode is constructed by a chemical plating method, including the following steps:

[0051] (1) Punch holes in zinc foil with a punching machine to make circular sheets with a diameter of 12mm, thus obtaining zinc discs;

[0052] (2) At room temperature, the zinc discs obtained in step (1) are ultrasonically treated with hydrochloric acid, acetone and ethanol in sequence to obtain the treated zinc discs.

[0053] (3) The second metal is copper, which is less reactive than zinc, to prepare a copper chloride solution with a concentration of 0.1 mol / L. The solvent of the copper chloride solution is water. Then the suspension is allowed to stand, separated, and the clear and transparent solution is taken as the chemical plating solution.

[0054] (4) Immerse a zinc disc with a diameter of 12 mm in a chemical plating solution, allowing both sides of the zinc disc to be chemically plated for 1 minute. Remove the disc and clean it to obtain a zinc metal battery negative electrode with copper-based metal as the second metal electric field shielding layer. Its surface morphology is as follows: Figure 1 As shown.

[0055] Comparative Example 1

[0056] A zinc anode material is a pure zinc sheet, which is used after being cleaned sequentially with deionized water, ethanol, acetone, etc.

[0057] Example 2

[0058] This embodiment provides an alkaline zinc-based battery, wherein the negative electrode material is the zinc negative electrode with a second metal electric field shielding layer prepared in Example 1, and the battery preparation process is as follows:

[0059] A mixed solution containing 6 mol / L potassium hydroxide and 0.2 mol / L zinc acetate was prepared as the electrolyte; the negative electrode material obtained in Example 1 was used as the working electrode to assemble a symmetrical cell.

[0060] Comparative Example 2

[0061] This comparative example provides an alkaline zinc-based battery, wherein the negative electrode material is the zinc negative electrode obtained in Comparative Example 1, and the battery preparation process is as follows:

[0062] A mixed solution containing 6 mol / L potassium hydroxide and 0.2 mol / L zinc acetate was prepared as the electrolyte; the zinc negative electrode obtained in Comparative Example 1 was used as the working electrode to assemble a symmetrical cell.

[0063] To illustrate the suppressive effect of the second metal electric field shielding layer of the present invention on the passivation of the zinc negative electrode, an uncoated zinc sheet (Comparative Example 1) was selected for electrochemical performance comparison. At a current density of 1 mA cm⁻¹... -2 Under these conditions, constant current discharge tests were performed on the batteries in Example 2 and Comparative Example 2. Thanks to the unique Faraday cage structure, the second metal electric field shielding layer on the zinc anode surface in Example 1 can shield the negative impact of the interface electric field on delamination, greatly reducing the passivation rate. This allows the symmetrical battery assembled in Example 1 to achieve a stable discharge capacity exceeding 95 mAh, far greater than the discharge capacity of Comparative Example 1. Figure 2 Thanks to the superior performance provided by the second metallic electric field shielding layer, the cycle life and stability of the symmetric battery are also greatly improved, achieving a cycle life of 0.5 mAh cm⁻¹. -2 The capacity and 1mA cm -2 Long cycling at current density (270 cycles). Figure 3 )

[0064] Example 3

[0065] This embodiment provides the application of a second metal electric field shielding layer on a zinc negative electrode in an alkaline zinc-based battery.

[0066] A mixed solution of 6 mol / L potassium hydroxide and 0.2 mol / L zinc acetate was prepared as the electrolyte. The zinc negative electrode material (i.e., negative electrode sheet) of Example 1 was placed on the titanium current collector, the separator was placed on the negative electrode sheet, 40 μL of electrolyte was added, the catalytic positive electrode (Pt / C) was placed on it, and finally the titanium current collector was placed on it. The battery mold was then tightened to obtain a zinc-air full cell.

[0067] Comparative Example 3

[0068] Assemble the battery according to the method in Example 3, replacing the negative electrode with a pure zinc sheet.

[0069] The zinc-air battery provided in Example 3 uses Pt / C coated on carbon paper as the positive electrode and the zinc negative electrode material of Example 1 as the negative electrode. This overcomes the problem of capacity loss caused by severe passivation during discharge of traditional zinc negative electrodes. Thanks to the excellent performance provided by the second metallic electric field shielding layer, a significant increase in the full cell power density (90 mW / cm²) is achieved in a low electrolyte (40 μL) environment. -2 , Figure 4 ).

[0070] In summary, the present invention constructs a zinc anode with a second metal electric field shielding layer. By comparing symmetrical batteries and zinc-air battery data, it is shown that the zinc anode of the present invention significantly increases the depth of discharge, thereby significantly improving the power density and cycle life of the battery. In addition, the alkaline zinc-based battery provided in the embodiments of the present invention uses low-toxicity and non-toxic reagents in its preparation process, and the aqueous solution also meets the requirements of green environmental protection and low energy consumption.

[0071] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An alkaline zinc-based battery, characterized in that, The invention includes a zinc anode material, a cathode material, and an alkaline electrolyte. The zinc anode material comprises a zinc anode and a second metal electric field shielding layer constructed on both sides thereon. A Faraday cage space is formed between the zinc anode and the second metal electric field shielding layer. The Faraday cage space can shield the external electric field, so that the dissolution of the zinc anode at the interface is mainly spontaneous dissolution, while promoting the mass transfer process of hydroxide ions. The second metal electric field shielding layer is a metal material with lower reactivity than zinc, and the thickness of the second metal electric field shielding layer is 5-30 μm; The construction methods for the second metal electric field shielding layer include chemical plating, electroplating, and drop coating. When constructing a second metallic electric field shielding layer on the zinc negative electrode using a chemical plating method in the alkaline zinc-based battery, the following steps are included: S1: Ultrasonic treatment of zinc metal foil or zinc alloy foil to obtain treated zinc sheets; S2: Dissolve and stir the second metal salt, which is less reactive than zinc, to obtain a suspension of the second metal salt. Let it stand, separate, and take the clear and transparent solution as the soluble solution of the second metal salt. S3: Place the treated zinc sheet obtained in step S1 into a soluble solution of the second metal salt obtained in step S2, construct a second metal electric field shielding layer on both sides of the zinc sheet by chemical plating, and clean it to obtain the zinc negative electrode material.

2. The alkaline zinc-based battery according to claim 1, characterized in that, The alkaline zinc-based battery includes zinc / air batteries, zinc / nickel batteries, zinc / silver batteries, and zinc / manganese batteries. The alkaline electrolyte includes a mixed solution of potassium hydroxide and zinc salt. In the mixed solution, the concentration of potassium hydroxide is 1-12 mol / L, and the concentration of zinc salt is 0-0.2 mol / L. The zinc salt is one or more of zinc acetate, zinc chloride, and zinc oxide.

3. The alkaline zinc-based battery according to claim 1, characterized in that, The zinc negative electrode is selected from any one of zinc metal or zinc alloy foil, sheet, or plate.

4. An alkaline zinc-based battery according to claim 1, characterized in that, In step S2, the concentration of the second metal ion in the second metal salt suspension is 0.01-2 mol / L.

5. An alkaline zinc-based battery according to claim 1, characterized in that, In step S2, the solvent in the soluble solution of the second metal salt is selected from one or more of water, ethanol, ethylene glycol, acetone, and glycerol, and the anion in the second metal salt is selected from one or more of chloride ion, sulfate ion, nitrate ion, and phosphate ion.

6. An alkaline zinc-based battery according to claim 1, characterized in that, In step S3, the time for chemical plating is 1-10 minutes.

7. The application of an alkaline zinc-based battery as described in any one of claims 1-6 in hearing aid batteries, automotive power, and mobile power.

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