Alloy electrode, zinc metal battery composite electrode and preparation method thereof, and zinc battery

Abstract

The invention relates to the technical field of zinc metal batteries, in particular to an alloy electrode, a zinc metal battery composite electrode, a preparation method thereof and a zinc battery. Raw materials of the alloy electrode comprise a zinc metal sheet with a cavity, a cladding layer covering the bottom of the cavity and a metal fluid injected into the cavity. The thickness of the cladding layer, the cladding power and the rate of injecting the metal fluid meet the following formula: s * v / 6000 d is greater than or equal to 1 and less than or equal to 1.05; wherein s is the rate of injecting the metal fluid, and the unit is mg / s; d is the thickness of the cladding layer, and the unit is mm; v is the cladding power, and the unit is W. The zinc metal composite electrode prepared through the method can relieve volume expansion and prolong the cycle life of the battery, the preparation method for preparing the zinc metal composite electrode through liquid metal pouring is simple, raw materials are rich, the cost is low, and wide application and industrialization of the zinc battery are promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc metal batteries, and in particular to an alloy electrode, a zinc metal battery composite electrode, a preparation method thereof, and a zinc battery. Background Art

[0002] Lithium-ion batteries have dominated the portable electronic device market due to their advantages such as high energy density and long cycle life. However, lithium is a rare substance in the Earth's crust and is relatively expensive, while zinc is abundant and inexpensive, making zinc batteries relatively inexpensive. As a non-toxic element, zinc has a low impact on the environment during production and waste disposal. Compared to the flammable organic electrolytes in lithium-ion batteries, the aqueous electrolytes used in zinc batteries are safer, which greatly reduces the risk of fire and explosion. In addition, zinc has a high theoretical capacity (820 mAh / g) and can achieve a long cycle life under appropriate conditions. The pursuit of low cost and high energy has driven the development of solid-state zinc metal batteries.

[0003] However, the contact between the zinc metal negative electrode and the ceramic electrolyte is not close at present. In the subsequent zinc ion deintercalation process, there will be poor contact at the solid-solid interface, serious zinc deposition and side reactions, structural collapse and large volume expansion. During the charging and discharging process, zinc may form dendrites, which may cause internal short circuits in the battery and reduce battery life. Constructing a suitable solid-phase interface is currently a better strategy. CN113839080B discloses a method for preparing an alloy electrode, which uses a simple three-step rolling process to obtain a lithium alloy negative electrode, without directly fusing the alloy layer well. CN118919648A discloses a method of placing an alloy on one side of a metal by evaporation. The preparation process is relatively complicated and easily leads to problems such as uneven evaporated alloy layer and inaccurate thickness control. CN103022449A discloses a method for preparing a multilayer alloy electrode by direct current plating, which has problems such as complex operation process and uneven coating. CN119663205A discloses a method for obtaining an alloy negative electrode current collector by magnetron sputtering followed by calcination. The operation process of this method is complicated, the process is relatively cumbersome, and the operability is low. CN119673975A discloses a method for preparing an alloy electrode by the charge and discharge reaction of a battery cell, and the transition of the alloy between lithium-rich and lithium-poor states is achieved by regulating the voltage range. This method is relatively idealistic, and there are side reactions in the charge and discharge process of the battery cell, which makes it impossible to obtain an ideal alloy layer. At present, the reported alloying methods can be mainly divided into physical, chemical and electrochemical methods. The physical method is to directly bond the electrode sheet and the metal foil sheet together through mechanical action, and roll them under a certain pressure. It is easy to damage the electrode sheet, and the electrode sheet yield is low, resulting in high cost. In addition, because the metal is relatively active, the operating environment, such as the water oxygen value, is very demanding to prevent the oxidation of the metal sheet. The chemical method is to alloy through electrochemical reaction, which requires charging and discharging reactions. The process is cumbersome and the preparation conditions are harsh. It cannot be applied on a large scale, and it has strict requirements on reaction time, side reactions in the process, and uniform dispersion of the electrode surface. Electrochemistry mainly uses electroplating to achieve pre-sodiumization by controlling the current, but the process is relatively complicated, the process time is long, and there will be problems with uneven alloy coating.

[0004] Currently, there is an urgent need to provide a novel method for preparing a zinc metal battery composite electrode and a zinc metal battery. Summary of the Invention

[0005] To address the above technical issues, the present invention provides an alloy electrode, a zinc metal battery composite electrode, a preparation method thereof, and a zinc battery. The zinc metal composite electrode prepared using the method provided herein can mitigate volume expansion and improve the battery's cycle life. The preparation of the zinc metal composite electrode by liquid metal infusion is simple, uses abundant raw materials, and is low-cost, which is conducive to promoting the widespread application and industrialization of zinc batteries.

[0006] In a first aspect, the present invention provides an alloy electrode, comprising a zinc metal sheet having a cavity, a cladding layer covering the bottom of the cavity, and a metal fluid injected into the cavity; the thickness of the cladding layer, the cladding power, and the rate of injection of the metal fluid satisfy the following formula: 1≤s*v / 6000d≤1.05; wherein s is the rate of injection of the metal fluid, in mg / s; d is the thickness of the cladding layer, in mm; and v is the cladding power, in W. In the present invention, controlling the thickness of the cladding layer is the primary factor affecting the degree of alloying. A relatively thin cladding layer has a larger contact area between the base material and the cladding material, making it easier for elements in the base material to diffuse into the cladding layer. As the thickness of the cladding layer increases, the contact area between the base material and the cladding material decreases, the diffusion distance increases, and the degree of alloying decreases. Furthermore, a thicker cladding layer may form a distinct interface, resulting in distinct interface stratification, and even the formation of different phase regions, which affects the consistency of the alloying and hinders further diffusion of elements. Similarly, higher laser power can provide more energy, which is beneficial for mixing between the base material and the cladding material. However, too high power may lead to an overly large molten pool, which is not conducive to uniform alloying. Lower laser power may not be enough to fully melt the base material, resulting in a low degree of alloying. When s*v / 6000d>1.05, the cladding power is too high and the cladding layer thickness is thick, affecting the consistency of metal alloying. When s*v / 6000d<1, the cladding power is too low, the cladding layer is too thin, and the base material alloying is insufficient.

[0007] Preferably, the cladding layer and the metal fluid are independently Sn, Mg, Al, Ag or Ca.

[0008] Preferably, the alloying degree of the alloy electrode is ≥85%, preferably ≥87%, for example, 87%, 88%, 90%, 92%, 94%, 95%, 96%, 97%, 98%, etc.

[0009] In a second aspect, the present invention provides a zinc metal battery composite electrode, wherein the zinc metal battery composite electrode comprises the alloy electrode.

[0010] Preferably, the molecular formula of the zinc metal battery composite electrode is Zn a X b Y c ; wherein, 85≤a≤98, 2≤b≤15, 3≤c≤5, X and Y are each independently Sn, Mg, Al, Ag or Ca; X is preferably Sn, Mg, Al, Ag or Ca; Y is preferably Mg, Al, Ag or Ca.

[0011] In a third aspect, the present invention provides a method for preparing a zinc metal battery composite electrode, comprising: 1) Prepare a cavity on a zinc metal sheet.

[0012] 2) preparing the first metal into gas-atomized metal powder.

[0013] 3) preparing the gas atomized metal powder as a cladding layer at the bottom of the cavity.

[0014] 4) injecting a metal fluid obtained by the first heat treatment of the second metal into the cavity for a second heat treatment, wherein the first metal and the second metal are each independently Sn, Mg, Al, Ag or Ca.

[0015] In this method, an alloy layer is formed within the cavity wall of the metal electrode. A fluid metal is then injected into the cavity, creating a "sandwich" structure. After cooling and heat treatment, a zinc-metal battery composite electrode with a defined phase composition is formed. Unlike traditional cold-rolling methods to produce metal alloys, injecting fluid metal into the metal cavity allows for the manipulation of the material's internal composition and structure. Furthermore, the alloy layer structure of the cavity wall, compared to pure metal walls, introduces reactive sites, improving overall reaction efficiency.

[0016] Preferably, step 1) includes laser processing the zinc metal sheet to obtain a zinc metal sheet with an internal cavity structure. In the present invention, the cavity is located within the zinc metal sheet and is in the shape of a rectangular parallelepiped, with dimensions of, for example, 1 cm * 0.6 cm * 0.3 mm. The cavity is not closed but open, i.e., it has an opening, such as an opening located on the side wall of the zinc metal sheet, to facilitate subsequent operations such as sandblasting and liquid metal injection.

[0017] In the present invention, the cladding layer, i.e., the inner cavity wall, is prepared by laser cladding. Of course, preparation by magnetron sputtering, evaporation, etc. is also within the protection scope of the present invention.

[0018] Preferably, in step 2) and step 4), the first metal and the second metal are each independently Sn, Mg, Al, Ag or Ca.

[0019] Preferably, in step 2), the first metal is melted and atomized under an inert atmosphere; preferably, the melting temperature is 700-1000°C and the melting time is 30-50 minutes. Preferably, the inert atmosphere during the melting is high-purity argon, high-purity helium, or high-purity nitrogen.

[0020] Preferably, in step 2), the atomization temperature is 800-1000°C, the atomization pressure is 3-6 MPa, and the atomization time is 10-30 minutes. The present invention involves smelting a metal or its oxide under an inert atmosphere and performing an atomization reaction under specific conditions. The resulting gas-atomized metal powder, after post-treatment, exhibits excellent physical and chemical properties, effectively improving the structure and performance of the electrode and facilitating more stable alloy formation during the subsequent alloying process.

[0021] Preferably, step 2) further includes post-treatment, wherein the post-treatment includes plasma treatment. The present invention does not limit the conditions for the plasma treatment, and conventional conditions in the art may be used. In the present invention, the plasma treatment activates the surface of the metal powder and enhances its surface activity.

[0022] Preferably, in step 3), the gas atomized metal powder is used to perform laser cladding in an inert atmosphere to form a cladding layer covering the bottom of the cavity.

[0023] Further preferably, the process parameters of the laser cladding are: laser power 1500-1700 W, spot diameter 1-3 mm, cladding speed 2000-4000 mm / min, and powder feeding speed 5-20 mg / s.

[0024] Preferably, in step 3), the inert atmosphere during the laser cladding is high-purity argon, high-purity helium or high-purity nitrogen, and the inert gas flow rate is 10-13 L / min.

[0025] Preferably, in step 3), the thickness of the cladding layer is 1.0-2.2 mm, preferably 1.0-2.0 mm, such as 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.8 mm, 2.0 mm, etc. The preferred cladding layer thickness can further improve the performance of the composite electrode and zinc battery.

[0026] Preferably, step 3) further comprises sandblasting the bottom of the cavity before preparing the cladding layer. In the present invention, the sandblasting can effectively remove the oxide layer on the metal surface, obtaining a fresh metal electrode and ensuring surface cleanliness.

[0027] More preferably, the sandblasting treatment conditions include: a sandblasting pressure of 0.4-0.8 MPa, a distance between the nozzle and the zinc sheet of 15-30 cm, and a spray angle of 45-60°. The surface effect after treatment under the preferred conditions is better.

[0028] Preferably, in step 4), the temperature of the first heat treatment is 500-800°C.

[0029] Preferably, in step 4), the metal liquid is injected at a flow rate of 5-10 mg / s, the injection time is 8-10 seconds, and the reaction is allowed to cool naturally for 8-12 hours. By optimizing the conditions for injecting the metal liquid, the present invention can further enhance the degree of alloying, strengthen the structural stability and overall performance of the electrode, and improve the battery's cycling performance.

[0030] Preferably, in step 4), the temperature of the second heat treatment is 400-600° C., and the time is 10-12 hours.

[0031] In a fourth aspect, the present invention provides a zinc battery, which is a zinc metal battery composite electrode prepared using the above-mentioned zinc metal battery composite electrode or the above-mentioned method for preparing the zinc metal battery composite electrode.

[0032] The present invention has at least the following beneficial effects: by injecting fluid metal into the metal cavity, the present invention optimizes and controls the internal composition and structure of the material; Furthermore, after pre-alloying the inner wall of the cavity, multiple active zinc sources are formed, effectively mitigating the volume expansion generated during the subsequent alloying reaction, increasing the degree of alloying, and enhancing the structural stability and overall performance of the electrode, thereby improving the battery's cycling performance. The zinc-metal composite electrode preparation method provided by the present invention not only mitigates volume expansion, effectively suppresses the volume effect, and prolongs cycle life, but also features a simple process, a wide range of raw material sources, and low manufacturing costs, contributing to the widespread application and industrial development of zinc batteries in energy storage and other fields. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to form one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed in the present invention.

[0035] Any embodiment described herein as "exemplary" is not necessarily to be construed as advantageous over other embodiments.

[0036] Where specific techniques or conditions are not specified in the examples of the present invention, the techniques or conditions described in literature in the field or in accordance with the product specifications were followed. Apparatus, instruments, reagents, etc. used, where the manufacturer is not specified, are conventional products available through regular channels. All experimental reagents and raw materials involved are commercially available.

[0037] The sandblasting machine used in the embodiment of the present invention is Comco Inc ProCenter Plus TM The fiber laser used is SPI Lasers redENERGY G4.

[0038] Example 1 1) The zinc metal electrode was pre-processed using a fiber laser. The size of the zinc metal electrode was 1.5 cm * 1 cm * 1 cm. The laser power was set to 80 W, and the scanning speed was 100 mm / s. The focal length of the laser head was adjusted to ensure that the focus was on the surface of the zinc sheet. A design drawing of the electrode sheet was drawn, including the position, size, and depth of the cavity. The laser cutting program was started according to the design drawing, and cutting was performed along the predetermined path. Finally, a zinc metal electrode sheet containing a cavity (the cavity size was 1 cm * 0.6 cm * 0.3 mm) was obtained. The reserved opening was located on the side wall of the electrode sheet and had an area of ​​0.6 cm * 0.3 mm.

[0039] 2) The tin powder was placed in a melting furnace and smelted at 1000°C for 20 minutes under high-purity nitrogen. It was then atomized at 800°C and a pressure of 5 MPa for 10 minutes. The surface of the tin powder was activated by plasma treatment using a radio frequency plasma device with an oxygen flow rate of 30 sccm, an argon flow rate of 70 sccm, a power setting of 100 W, and an operating pressure of 0.3 Torr. The chamber environment was monitored by a built-in pressure sensor to ensure that the operating pressure was maintained at 0.3 Torr. The treatment time was 10 minutes, and the instrument was then turned off to allow the sample to cool naturally to room temperature. A gas-atomized tin metal powder with a particle size of 40 μm was then obtained.

[0040] 3) The inner wall of the zinc metal electrode cavity was sandblasted at a pressure of 0.6 MPa, a nozzle-to-cavity distance of 20 cm, and a spray angle of 45°, resulting in a zinc metal electrode cavity with high surface cleanliness. The protective atmosphere was adjusted to nitrogen at a gas flow rate of 12 L / min. The laser parameters were adjusted to a laser power of 1050 W, a spot diameter of 1 mm, a cladding speed of 2000 mm / min, and a powder feed rate of 10 mg / s, resulting in a zinc-tin alloy electrode cavity wall with a cladding layer thickness of 1.0 mm.

[0041] 4) After heat treatment at 700℃, magnesium metal fluid was obtained, which was then injected into the cavity of the zinc metal electrode at a rate of 6 mg / s for 8 seconds. After natural cooling for 12 hours, Zn was obtained after heat treatment at 550℃ for 10 hours. 90 Sn6Mg4 alloy electrode.

[0042] Comparative Example 1 1) The zinc metal electrode was pre-processed using a fiber laser. The size of the zinc metal electrode was 1.5 cm * 1 cm * 1 cm. The laser power was set to 80 W, and the scanning speed was 100 mm / s. The focal length of the laser head was adjusted to ensure that the focus was on the surface of the zinc sheet. A design drawing of the electrode sheet was drawn, including the position, size, and depth of the cavity. The laser cutting program was started according to the design drawing, and cutting was performed along the predetermined path. Finally, a zinc metal electrode sheet containing a cavity (the cavity size was 1 cm * 0.6 cm * 0.3 mm) was obtained. The reserved opening was located on the side wall of the electrode sheet and had an area of ​​0.6 cm * 0.3 mm.

[0043] 2) The tin powder was placed in a melting furnace and smelted at 1000°C for 20 minutes under high-purity nitrogen. It was then atomized at 800°C and a pressure of 5 MPa for 10 minutes. The surface of the tin powder was activated by plasma treatment using a radio frequency plasma device with an oxygen flow rate of 30 sccm, an argon flow rate of 70 sccm, a power setting of 100 W, and an operating pressure of 0.3 Torr. The chamber environment was monitored by a built-in pressure sensor to ensure that the operating pressure was maintained at 0.3 Torr. The treatment time was 10 minutes, and the instrument was then turned off to allow the sample to cool naturally to room temperature. A gas-atomized tin metal powder with a particle size of 40 μm was then obtained.

[0044] 3) The inner wall of the zinc metal electrode cavity was sandblasted at a pressure of 0.6 MPa, a nozzle-to-cavity distance of 20 cm, and a spray angle of 45°, resulting in a zinc metal electrode cavity with high surface cleanliness. The protective atmosphere was adjusted to nitrogen at a gas flow rate of 12 L / min. The laser parameters were adjusted to a laser power of 1700 W, a spot diameter of 1 mm, a cladding speed of 2000 mm / min, and a powder feed rate of 10 mg / s, resulting in a zinc-tin alloy electrode inner cavity wall with a cladding layer thickness of 0.85 mm.

[0045] 4) After heat treatment at 700℃, magnesium metal fluid was obtained, which was then injected into the cavity of the zinc metal electrode at a rate of 6 mg / s for 8 seconds. After natural cooling for 12 hours, Zn was obtained after heat treatment at 550℃ for 10 hours. 90 Sn6Mg4 alloy electrode.

[0046] Example 2 1) The zinc metal electrode was pre-processed using a fiber laser. The size of the zinc metal electrode was 1.5 cm * 1 cm * 1 cm. The laser power was set to 80 W, and the scanning speed was 100 mm / s. The focal length of the laser head was adjusted to ensure that the focus was on the surface of the zinc sheet. A design drawing of the electrode sheet was drawn, including the position, size, and depth of the cavity. The laser cutting program was started according to the design drawing, and cutting was performed along the predetermined path. Finally, a zinc metal electrode sheet containing a cavity (the cavity size was 1 cm * 0.6 cm * 0.3 mm) was obtained. The reserved opening was located on the side wall of the electrode sheet and had an area of ​​0.6 cm * 0.3 mm.

[0047] 2) The tin metal was placed in a melting furnace and smelted at 1000°C for 20 minutes under high-purity nitrogen. It was then atomized at 800°C and a pressure of 5 MPa for 10 minutes. The surface of the tin powder was activated by plasma treatment using a radio frequency plasma device with an oxygen flow rate of 30 sccm, an argon flow rate of 70 sccm, a power setting of 100 W, and an operating pressure of 0.3 Torr. The chamber environment was monitored by a built-in pressure sensor to ensure that the operating pressure was maintained at 0.3 Torr. The treatment time was 10 minutes, and the instrument was then turned off to allow the sample to cool naturally to room temperature. A gas-atomized tin metal powder with a particle size of 40 μm was then obtained.

[0048] 3) The inner wall of the zinc metal electrode cavity was sandblasted at a pressure of 0.6 MPa, a nozzle-to-cavity distance of 20 cm, and a spray angle of 45°, resulting in a highly clean zinc metal electrode cavity. The protective atmosphere was adjusted to nitrogen at a flow rate of 12 L / min. The laser parameters were adjusted to a laser power of 1800 W, a spot diameter of 1 mm, a cladding speed of 2000 mm / min, and a powder feed rate of 10 mg / s. The resulting cladding layer on the zinc-tin alloy electrode cavity wall was 1.8 mm thick.

[0049] 4) After heat treatment at 700℃, magnesium metal fluid was obtained, which was then injected into the cavity of the zinc metal electrode at a rate of 6 mg / s for 8 seconds. After natural cooling for 12 hours, Zn was obtained after heat treatment at 550℃ for 10 hours. 90 Sn6Mg4 alloy electrode.

[0050] Comparative Example 2 1) The zinc metal electrode was pre-processed using a fiber laser. The size of the zinc metal electrode was 1.5 cm * 1 cm * 1 cm. The laser power was set to 80 W, and the scanning speed was 100 mm / s. The focal length of the laser head was adjusted to ensure that the focus was on the surface of the zinc sheet. A design drawing of the electrode sheet was drawn, including the position, size, and depth of the cavity. The laser cutting program was started according to the design drawing, and cutting was performed along the predetermined path. Finally, a zinc metal electrode sheet containing a cavity (the cavity size was 1 cm * 0.6 cm * 0.3 mm) was obtained. The reserved opening was located on the side wall of the electrode sheet and had an area of ​​0.6 cm * 0.3 mm.

[0051] 2) Tin oxide was placed in a melting furnace and smelted at 1000°C for 20 minutes under high-purity nitrogen. It was then atomized at 800°C and a pressure of 5 MPa for 10 minutes. The surface of the tin powder was activated by plasma treatment using a radio frequency plasma device with an oxygen flow rate of 30 sccm, an argon flow rate of 70 sccm, a power setting of 100 W, and an operating pressure of 0.3 Torr. The chamber environment was monitored by a built-in pressure sensor to ensure that the operating pressure was maintained at 0.3 Torr. The treatment time was 10 minutes, and the instrument was then turned off to allow the sample to cool naturally to room temperature. A gas-atomized tin metal powder with a particle size of 40 μm was then obtained.

[0052] 3) The inner wall of the zinc metal electrode cavity was sandblasted at a pressure of 0.6 MPa, a nozzle-to-cavity distance of 20 cm, and a spray angle of 45°, resulting in a highly clean zinc metal electrode cavity. The protective atmosphere was adjusted to nitrogen at a flow rate of 12 L / min. The laser parameters were adjusted to a laser power of 1800 W, a spot diameter of 1 mm, a cladding speed of 2000 mm / min, and a powder feed rate of 10 mg / s. A 2.0 mm thick zinc-tin alloy cladding layer was obtained on the inner wall of the zinc metal electrode cavity.

[0053] 4) After heat treatment at 700℃, magnesium metal fluid was obtained, which was then injected into the cavity of the zinc metal electrode at a rate of 6 mg / s for 8 seconds. After natural cooling for 12 hours, Zn was obtained after heat treatment at 550℃ for 10 hours. 90 Sn6Mg4 alloy electrode.

[0054] Example 3 1) The zinc metal electrode was pre-processed using a fiber laser. The size of the zinc metal electrode was 1.5 cm * 1 cm * 1 cm. The laser power was set to 80 W, and the scanning speed was 100 mm / s. The focal length of the laser head was adjusted to ensure that the focus was on the surface of the zinc sheet. A design drawing of the electrode sheet was drawn, including the position, size, and depth of the cavity. The laser cutting program was started according to the design drawing, and cutting was performed along the predetermined path. Finally, a zinc metal electrode sheet containing a cavity (the cavity size was 1 cm * 0.6 cm * 0.3 mm) was obtained. The reserved opening was located on the side wall of the electrode sheet and had an area of ​​0.6 cm * 0.3 mm.

[0055] 2) Tin oxide was placed in a melting furnace and smelted at 1000°C for 20 minutes under high-purity nitrogen. It was then atomized at 800°C and a pressure of 5 MPa for 10 minutes. The surface of the tin powder was activated by plasma treatment using a radio frequency plasma device with an oxygen flow rate of 30 sccm, an argon flow rate of 70 sccm, a power setting of 100 W, and an operating pressure of 0.3 Torr. The chamber environment was monitored by a built-in pressure sensor to ensure that the operating pressure was maintained at 0.3 Torr. The treatment time was 10 minutes, and the instrument was then turned off to allow the sample to cool naturally to room temperature. A gas-atomized tin metal powder with a particle size of 40 μm was then obtained.

[0056] 3) The inner wall of the zinc metal electrode cavity was sandblasted at a pressure of 0.6 MPa, a nozzle-to-cavity distance of 20 cm, and a spray angle of 45°, resulting in a highly clean zinc metal electrode cavity. The protective atmosphere was adjusted to nitrogen at a flow rate of 12 L / min. Laser parameters were adjusted to a power of 1224 W, a spot diameter of 1 mm, a cladding speed of 2000 mm / min, and a powder feed rate of 10 mg / s. Atomized tin metal powder was used. A 1.2 mm thick cladding layer was obtained on the inner wall of the zinc-tin alloy electrode cavity.

[0057] 4) After heat treatment at 700℃, magnesium metal fluid was obtained, which was then injected into the cavity of the zinc metal electrode at a rate of 6 mg / s for 8 seconds. After natural cooling for 12 hours, Zn was obtained after heat treatment at 550℃ for 10 hours. 90 Sn6Mg4 alloy electrode.

[0058] Preparation method of button cell: assembled in a glove box with high-purity argon, with the water and oxygen content controlled below 0.1 ppm; the electrolyte composition is 2M ZnSO4 + 0.1M MnSO4; the diaphragm is glass fiber.

[0059] Comparative Example 3 The zinc metal electrode sheet, the aluminum metal sheet, and the magnesium metal sheet are pre-pressed and rolled in sequence to obtain a first layer of alloy electrode; the magnesium metal sheet, the aluminum metal sheet, and the zinc metal electrode sheet are pre-pressed and rolled in sequence to obtain a second layer of alloy electrode; the first and second layer alloy electrodes are rolled to obtain a Zn composite alloy electrode.

[0060] Comparative Example 4 The magnesium metal was heat treated at 700 ° C to obtain a magnesium metal fluid, which was then injected into the cavity of the zinc metal electrode at 6 mg / s for 8 seconds. After natural cooling for 12 hours, the Zn composite alloy electrode was obtained after heat treatment at 550 ° C for 10 hours.

[0061] The zinc metal negative electrodes of Examples 1-3 and Comparative Examples 1-4 were cut into electrode sheets with a diameter of 12 mm, and button batteries were prepared using the above preparation method. The electrochemical performance of the batteries was tested, and the results are shown in Table 1. The test conditions for the electrochemical performance were: the current density was 1 mAh·cm 2 , the voltage range is 1.0-2.5 V.

[0062] Method for testing the degree of alloying: Crush the alloy sample into a fine powder to ensure uniformity. Weigh an appropriate amount of sample (e.g., 0.1 g), place it in a beaker, add an appropriate amount of hydrochloric acid, and slowly heat on a hot plate until the sample is completely dissolved. After cooling, transfer the solution to a volumetric flask and dilute it to a volume of 100 mL. Inject the prepared sample solution into the ICP-OES instrument and record the emission spectrum intensity of each element. Determine the ratio of elements in the alloy and the degree of alloying based on the calibration curve. The electrical performance test results of the alloy electrodes prepared in various examples of the present invention are listed in Table 1, where K = s * v / 6000d ≤ 1.05; where s is the injection rate of the metal fluid, in mg / s; d is the thickness of the cladding layer, in mm; and v is the cladding power, in W.

[0063] Table 1 Electrical performance data of alloy electrode half-cells with different preparation parameters

[0064] As can be seen from Table 1, from Examples 1-3 and Comparative Examples 1-4, the degree of alloying of the composite alloy electrode has a certain influence on the electrical properties. When the thickness of the cladding layer is too thin / too thick, the charging capacity and the initial efficiency will both decrease. Moreover, if the degree of alloying is low after direct mechanical cold rolling treatment, the capacity retention rate in the later stage will be poor. If the cavity wall is not alloyed and the metal is directly injected, the degree of alloying is still low, and the volume expansion in the later stage of the cycle cannot be well suppressed.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An alloy electrode, characterized in that: The alloy electrode includes a zinc metal sheet with a cavity, a cladding layer covering the bottom of the cavity, and a metal fluid injected into the cavity; the thickness of the cladding layer, the cladding power, and the rate of injecting the metal fluid satisfy the following formula: 1≤s*v / 6000d≤1.05; wherein s is the rate of injecting the metal fluid, in mg / s; d is the thickness of the cladding layer, in mm; and v is the cladding power, in W.

2. The alloy electrode according to claim 1, characterized in that The cladding layer and the metal fluid are independently Sn, Mg, Al, Ag or Ca.

3. The alloy electrode according to claim 1 or 2, characterized in that: The alloying degree of the alloy electrode is ≥85%.

4. A zinc metal battery composite electrode, characterized in that: The zinc metal battery composite electrode comprises the alloy electrode according to any one of claims 1 to 3; the molecular formula of the zinc metal battery composite electrode is Zn a X b Y c ; wherein, 85≤a≤98, 2≤b≤15, 3≤c≤5, X and Y are each independently Sn, Mg, Al, Ag or Ca.

5. The method for preparing the zinc metal battery composite electrode according to claim 4, characterized in that: include: 1) Preparing a cavity on a zinc metal sheet; 2) preparing the first metal into a gas-atomized metal powder; 3) preparing the gas atomized metal powder as a cladding layer at the bottom of the cavity; 4) injecting the metal fluid obtained by the first heat treatment of the second metal into the cavity and performing a second heat treatment.

6. The method for preparing a zinc metal battery composite electrode according to claim 5, characterized in that: In step 1), the zinc metal sheet is laser processed to obtain a zinc metal sheet with an internal cavity structure; And / or, in step 2) and step 4), the first metal and the second metal are each independently Sn, Mg, Al, Ag or Ca.

7. The method for preparing a zinc metal battery composite electrode according to claim 5, characterized in that: In step 2), the first metal is melted and atomized under an inert atmosphere; preferably, the melting temperature is 700-1000° C. and the melting time is 30-50 min; and / or, the atomization temperature is 800-1000°C, the atomization pressure is 3-6 MPa, and the atomization time is 10-30 min; And / or, further comprising performing a post-treatment, wherein the post-treatment comprises a plasma treatment.

8. The method for preparing a zinc metal battery composite electrode according to claim 5, characterized in that: In step 3), the gas atomized metal powder is laser clad in an inert atmosphere to form a cladding layer covering the bottom of the cavity; preferably, the laser power is 1500-1700 W, the spot diameter is 1-3 mm, the cladding speed is 2000-4000 mm / min, and the powder feeding speed is 5-20 mg / s; And / or, the thickness of the cladding layer is 1.0-2.2 mm; And / or, it also includes sandblasting the bottom of the cavity and then preparing the cladding layer; the conditions of the sandblasting include: the sandblasting pressure is 0.4-0.8 MPa, the distance between the nozzle and the zinc metal sheet is 15-30 cm, and the spraying angle is 45-60°.

9. The method for preparing a zinc metal battery composite electrode according to any one of claims 5 to 8, characterized in that: In step 4), the temperature of the first heat treatment is 500-800°C; and / or, the flow rate of the injected metal liquid is 5-10 mg / s, the injection time of the metal liquid is 8-10 seconds, and the natural cooling is 8-12 hours; And / or, the temperature of the second heat treatment is 400-600° C., and the time is 10-12 hours.

10. A zinc battery, characterized in that: A zinc metal battery composite electrode prepared by the preparation method of the zinc metal battery composite electrode according to claim 4 or the zinc metal battery composite electrode according to any one of claims 5-9.

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