Alkaline zinc-based battery and preparation method and application thereof

Abstract

The invention relates to an alkaline zinc-based battery and a preparation method and application thereof.The alkaline zinc-based battery comprises a zinc negative electrode material, a positive electrode material and alkaline electrolyte, the zinc negative electrode material comprises a zinc negative electrode and second metal electric field shielding layers constructed on the two sides of the zinc negative electrode, and the zinc negative electrode is selected from any one of zinc metal or zinc alloy foil, sheet and plate; and the second metal electric field shielding layer is made of a metal material of which the activity is weaker than that of zinc. Compared with the prior art, a Faraday cage type space can be formed between the zinc negative electrode and the second metal electric field shielding layer, an external electric field can be shielded, formation of zinc oxide on the surface of the zinc negative electrode can be remarkably slowed down, uniform stripping of zinc is achieved, and the problem that the zinc negative electrode is seriously passivated in an alkaline system is solved; the utilization rate and the energy density of the zinc negative electrode in the alkaline primary battery are improved, and the long-term cycling stability and the service life of the alkaline secondary battery are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of alkaline zinc-based batteries, and in particular to an alkaline zinc-based battery and a preparation method and application thereof. Background Art

[0002] The increasing challenges of energy shortage and environmental pollution are driving a profound change in clean and renewable energy technologies worldwide. Developing advanced electrochemical energy storage devices is an important way to solve environmental and energy problems. Although lithium batteries have attracted much attention due to their wide application in the market, their high cost, dependence on rare metal resources, and potential safety hazards such as flammability and explosiveness limit their further application. Therefore, it is urgent to develop low-cost, high-safety new energy storage technologies to replace or supplement the existing system and promote the innovation and development of energy storage technologies.

[0003] Zinc-based batteries have the characteristics of high theoretical capacity, abundant resources, and environmental friendliness, and have great potential in the storage of intermittent renewable energy. In recent years, more and more researchers have been committed to developing zinc-based batteries with superior performance. Among various types of zinc-based batteries, alkaline zinc-based batteries show superior performance such as large theoretical capacity and high specific energy. However, in alkaline batteries, the passivation, side reaction, and dendrite problems of zinc anode are more severe than those in neutral acid systems. Among them, the passivation problem of zinc anode leads to lower zinc anode utilization, which greatly reduces the energy density of alkaline zinc-based batteries, and the passivated zinc anode surface has a serious negative impact on the cycle reversibility, limiting the widespread application of alkaline zinc-based batteries. However, compared with the progress made in zinc deposition process, there is still a lack of discussion and insights on the mitigation of passivation during zinc dissolution. Although research has been conducted on the manufacture of zinc oxide anodes with zinc metal and complex three-dimensional structures, the increase in electrode volume and large surface area exacerbates passivation, while additional conductive agents lead to the loss of active materials. Therefore, developing a zinc negative electrode material that can effectively prevent the passivation of the zinc negative electrode in alkaline electrolyte is crucial to 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 negative electrode material and its preparation method and application. The zinc negative electrode material is a ZnO / ZnS / C composite material or a metal-doped ZnO / ZnS / C composite material. The novel alkaline secondary battery negative electrode material can effectively reduce the deformation of the zinc negative electrode, inhibit the hydrogen evolution reaction and passivation of zinc dendrites, improve the stability of the zinc negative electrode in alkaline solution, and increase the cycle life of the alkaline secondary battery. However, the preparation method is complicated, the process requires precision, and the fundamental problem of passivation of the zinc negative electrode in the alkaline system is not solved.

[0005] CN106887581A discloses a zinc electrode material and its preparation and application. The electrode material is a micro-nano particle with a core-shell structure. It uses zinc as a core and a second metal (an alloy of one or more of iron, tin, lead, copper, silver, platinum, gold, indium, bismuth, thallium, gallium, and cadmium) as a shell. The second metal shell is wrapped around the outside of the zinc core, and there is a gap between the zinc core and the second metal shell. The zinc electrode material suppresses hydrogen evolution by controlling the dissolution of zinc oxide in the electrolyte, which effectively improves the cycle stability of the battery. However, its reaction conditions are strict, the process is complicated, and the inhibitory effect on the passivation of the zinc negative electrode surface is not good.

[0006] Therefore, it is of great practical significance to develop an alkaline zinc-based battery and zinc negative electrode material with a simple and feasible preparation method that can effectively inhibit the passivation of the zinc negative electrode surface. Summary of the invention

[0007] The purpose of the present invention is to provide an alkaline zinc-based battery and a preparation method and application thereof, which can effectively inhibit the problem of severe passivation caused by the generation of zinc oxide on the surface of the zinc negative electrode in an alkaline electrolyte.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] In one aspect, the present invention provides an alkaline zinc-based battery, comprising a zinc negative electrode material, a positive electrode material and an alkaline electrolyte, wherein the zinc negative electrode material comprises a zinc negative electrode 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, or a zinc / manganese battery.

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

[0012] Further 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, and plate.

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

[0016] Further preferably, the metal material with lower activity than zinc includes iron, copper, bismuth, tin, titanium, lead, silver and the like.

[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] In a second aspect, the present invention further provides a method for preparing the above alkaline zinc-based battery, wherein a second metal electric field shielding layer is constructed on a zinc negative electrode by chemical plating, comprising the following steps:

[0020] S1: ultrasonically treating zinc metal foil or zinc alloy foil to obtain a treated zinc sheet;

[0021] S2: dissolving and stirring a second metal salt whose activity is weaker than that of zinc to obtain a second metal salt suspension, allowing the suspension to stand, separating the suspension, and taking a clear and transparent solution as a soluble solution of the second metal salt;

[0022] S3: placing the treated zinc sheet obtained in step S1 in a soluble solution of the second metal salt obtained in step S2, constructing a second metal electric field shielding layer on both sides of the zinc sheet by chemical plating, and washing 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 anions in the second metal salt are selected from one or more of chloride ions, sulfate ions, nitrate ions and phosphate ions.

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

[0028] In a third aspect, the present invention also provides an application of the above-mentioned alkaline zinc-based battery in hearing aid batteries, vehicle energy, and mobile energy.

[0029] In the prior art, most of the control methods for constructing a metal protective layer on the surface of the zinc negative electrode are aimed at the behavior of the zinc negative electrode in a neutral acid system. In a neutral acid system such as zinc sulfate electrolyte, the half-reaction equation of 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 negative electrode in the neutral acid system and the alkaline system are completely different, and the ions formed are also different, and the passivation problem does not exist in the neutral acid zinc ion battery system. The solubility of the zincate ions formed in the alkaline system in the electrolyte is limited. When the dissolution reaches a certain concentration, supersaturation occurs and begins to aggregate and precipitate, forming a layer of inert zinc oxide passivation layer on the surface of the zinc negative electrode, which increases the dissolution overpotential of the zinc negative electrode and makes dissolution difficult. When a certain overpotential is reached, a solid precipitation reaction occurs at the zinc negative electrode to form a dense zinc oxide passivation layer, and the zinc negative electrode cannot continue to dissolve. At present, most of the research focuses on the regulation of the deposition process of the zinc negative electrode in the neutral acid system, while the present invention focuses on the passivation problem in the dissolution process of zinc. The passivation of the zinc negative electrode is directly caused by the electric field effect on the electrode surface, and the second metal electric field shielding layer and its construction method in the alkaline zinc-based battery provided by the present invention can effectively inhibit the generation of zinc oxide on the surface of the zinc negative electrode in the alkaline electrolyte, resulting in serious passivation.

[0034] At present, there are few studies on the dissolution process of zinc negative electrode in alkaline system, and the problem of zinc passivation in alkaline system has not received attention. At present, the modification of zinc negative electrode in alkaline system mainly includes 3D structure design, construction interface protection layer and zinc oxide structure modification. Although 3D structure design reduces current density by increasing surface area, it also inevitably aggravates passivation, and the interface protection layer can not only adjust the electric field, but also reduce the contact between electrolyte and electrode, and inhibit the occurrence of side reactions. The second metal electric field shielding layer of zinc negative electrode in the alkaline zinc-based battery of the present invention does not require a complicated preparation process, is simple and efficient to operate, has low requirements on experimental equipment and materials, and the prepared second metal electric field shielding layer is relatively uniform and flat, and has strong reversibility.

[0035] The present invention provides an alkaline zinc-based battery, wherein a second metal electric field shielding layer is constructed on the surface of the zinc negative electrode, which has a Faraday cage structure at a microscopic level, and a Faraday cage space is formed between the zinc negative electrode 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 negative electrode at the interface is dominated by spontaneous dissolution, while promoting the mass transfer process of hydroxide, thereby avoiding the loss and waste of the zinc negative electrode capacity.

[0036] The present invention proposes the concept of suppressing the passivation of the zinc negative electrode by adjusting the electric field in an alkaline system, and constructs a second metal electric field shielding layer for the zinc negative electrode. The present invention verifies through a large number of experiments that the second metal electric field shielding layer shields the external electric field during the zinc stripping process, suppresses the aggregation of zincates caused by the electric field at the zinc negative electrode interface, and significantly slows down the formation of zinc oxide on the surface of the zinc negative electrode. Compared with the prior art, 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 negative electrode in the alkaline system, greatly improves the utilization rate and energy density of the zinc negative electrode in the alkaline primary battery, and significantly improves the long-term cycle stability and service life in the alkaline secondary battery.

[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 negative electrode material comprises a zinc negative electrode and a second metal electric field shielding layer constructed on both sides thereof, and the construction of the second metal electric field shielding layer can effectively suppress the problem of severe passivation caused by the generation of zinc oxide on the surface of the zinc negative electrode in an alkaline electrolyte.

[0039] (2) The second metal electric field shielding layer constructed on the surface of the zinc negative electrode of the present invention can effectively inhibit the aggregation of zincates caused by the electric field at the zinc negative electrode interface, significantly slow down the formation of zinc oxide on the surface of the zinc negative electrode, achieve uniform stripping of zinc, and improve the problem of severe passivation of the zinc negative electrode in an alkaline system.

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

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

[0042] (5) The preparation process of the alkaline zinc-based battery provided by the present invention is simple, and the raw materials used are all low-toxic or non-toxic reagents, and the aqueous solution also meets the requirements of green environmental protection and low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0044] Figure 2 Graph showing discharge curves of the symmetrical battery in Example 2 of the present invention and Comparative Example 2 in a mixed solution electrolyte of 6 mol / L potassium hydroxide and 0.2 mol / L zinc acetate.

[0045] Figure 3 Graph showing the charge and discharge cycle of the symmetrical battery in Example 2 of the present invention and Comparative Example 2.

[0046] Figure 4 The power density discharge curve diagram of the zinc-air battery of Example 3 of the present invention and Comparative Example 3 is shown. DETAILED DESCRIPTION

[0047] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

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

[0049] Example 1

[0050] This embodiment provides a zinc negative electrode material in an alkaline zinc-based battery, wherein the zinc negative electrode material comprises a zinc negative electrode and a second metal electric field shielding layer constructed on both sides thereof, wherein the second metal electric field shielding layer on the zinc negative electrode is constructed by chemical plating, comprising the following steps:

[0051] (1) punching holes in zinc metal foil using a punching machine to form a circular sheet with a diameter of 12 mm to obtain a zinc circular sheet;

[0052] (2) at room temperature, ultrasonically treating the zinc disc obtained in step (1) with hydrochloric acid, acetone, and ethanol in sequence to obtain a treated zinc disc;

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

[0054] (4) A zinc disc with a diameter of 12 mm is immersed in a chemical plating solution, and both sides of the zinc disc are chemically plated for 1 minute. Then, the disc is taken out and cleaned to obtain a zinc metal battery negative electrode with a copper-based metal as the second metal electric field shielding layer. The surface morphology is as follows: Figure 1 shown.

[0055] Comparative Example 1

[0056] A zinc negative electrode material is a pure zinc sheet, which is only used after being washed in sequence 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, wherein the preparation process of the battery is as follows:

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

[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 preparation process of the battery is as follows:

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

[0063] In order to illustrate the inhibitory effect of the second metal electric field shielding layer of the present invention on the passivation of the zinc negative electrode, a zinc sheet without coating (Comparative Example 1) was selected for electrochemical performance comparison. -2 The batteries in Example 2 and Comparative Example 2 were subjected to constant current discharge tests under the conditions of . Thanks to the unique Faraday cage structure, the second metal electric field shielding layer on the surface of the zinc negative electrode in Example 1 can shield the negative impact of the electric field at the interface on the peeling, greatly reducing the speed of passivation, which enables the symmetrical battery assembled in Example 1 to obtain a stable discharge of more than 95 mAh, which is much larger than the discharge capacity of Comparative Example 1 ( Figure 2 Thanks to the excellent performance provided by the second metal electric field shielding layer, the cycle life and stability of the symmetric battery are also greatly improved, achieving a peak performance of 0.5 mAh cm -2 Capacity and 1mA cm -2 Long cycle at current density. (270 cycles, Figure 3 )

[0064] Example 3

[0065] This embodiment provides an application of the second metal electric field shielding layer of the 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 is prepared as an electrolyte; the zinc negative electrode material (i.e., the negative electrode sheet) of Example 1 is placed on a titanium current collector, the diaphragm is placed on the negative electrode sheet, 40 μL of the electrolyte is added, and then the catalytic positive electrode (Pt / C) is placed thereon, and finally the titanium current collector is placed, and the battery mold is tightened to obtain a zinc-air full battery.

[0067] Comparative Example 3

[0068] The battery was assembled according to the method in Example 3, and the negative electrode was replaced with a pure zinc sheet.

[0069] The zinc-air battery provided in Example 3 uses Pt / C sprayed on carbon paper as the positive electrode and the zinc negative electrode material of Example 1 as the negative electrode, which overcomes the problem of severe passivation of the traditional zinc negative electrode during discharge leading to capacity loss. Thanks to the excellent performance provided by the second metal electric field shielding layer, a significant improvement in the power density of the whole battery (90 mW cm-2) is achieved in the lean electrolyte (40 μL). -2 , Figure 4 ).

[0070] In summary, the present invention constructs a zinc negative electrode with a second metal electric field shielding layer. By comparing symmetrical batteries and zinc-air battery data, it is shown that the discharge depth of the zinc negative electrode of the present invention is significantly increased, thereby significantly improving the power density and cycle life of the battery; in addition, the raw materials used in the preparation process of the alkaline zinc-based battery provided by the embodiment of the present invention are all low-toxic and non-toxic reagents, and the aqueous solution also meets the requirements of green environmental protection and low energy consumption.

[0071] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and 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 present invention should be within the scope of protection of the present invention.

Claims

1. An alkaline zinc-based battery, characterized in that: The invention comprises a zinc negative electrode material, a positive electrode material and an alkaline electrolyte, wherein the zinc negative electrode material comprises a zinc negative electrode and a second metal electric field shielding layer constructed on both sides thereof.

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

3. An 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, and plate.

4. The alkaline zinc-based battery according to claim 1, characterized in that: The second metal electric field shielding layer is made of a metal material less active than zinc, and the thickness of the second metal electric field shielding layer is 5-30 μm.

5. An alkaline zinc-based battery according to claim 1, characterized in that: The construction method of the second metal electric field shielding layer includes chemical plating, electroplating and drop coating.

6. A method for preparing an alkaline zinc-based battery according to any one of claims 1 to 5, characterized in that: When the second metal electric field shielding layer is constructed on the zinc negative electrode by chemical plating, the following steps are included: S1: ultrasonically treating zinc metal foil or zinc alloy foil to obtain a treated zinc sheet; S2: dissolving and stirring a second metal salt whose activity is weaker than that of zinc to obtain a second metal salt suspension, allowing the suspension to stand, separating the suspension, and taking a clear and transparent solution as a soluble solution of the second metal salt; S3: placing the treated zinc sheet obtained in step S1 in a soluble solution of the second metal salt obtained in step S2, constructing a second metal electric field shielding layer on both sides of the zinc sheet by chemical plating, and washing to obtain the zinc negative electrode material.

7. The method for preparing the zinc negative electrode material in the alkaline zinc-based battery according to claim 6, 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.

8. The method for preparing the zinc negative electrode material in the alkaline zinc-based battery according to claim 6, 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, wherein the anions in the second metal salt are selected from one or more of chloride ions, sulfate ions, nitrate ions, and phosphate ions.

9. The method for preparing the zinc negative electrode material in the alkaline zinc-based battery according to claim 6, characterized in that: In step S3, the time of chemical plating is 1-10 minutes.

10. Use of the alkaline zinc-based battery according to any one of claims 1 to 5 in hearing aid batteries, vehicle energy, and mobile energy.

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