Negative pole piece of nickel-metal hydride battery and nickel-metal hydride battery

Abstract

The invention relates to a negative pole piece of a nickel-metal hydride battery and the nickel-metal hydride battery. The negative pole piece of the nickel-metal hydride battery comprises a negative pole current collector, a negative pole material layer arranged on at least one side of the negative pole current collector, and a conductive corrosion-resistant layer coating the negative pole material layer, wherein the conductive corrosion-resistant layer comprises a conductive corrosion-resistant alloy, the conductive corrosion-resistant alloy comprises a first metal material and a second metal material, and the conductivity of the first metal material is superior to that of the second metal material. According to the scheme provided by the invention, corrosion of the nickel-metal hydride battery negative electrode material hydrogen storage alloy can be inhibited, and the cycle life and the rate capability of the nickel-metal hydride battery are improved.

Description

Technical Field

[0001] The present application relates to the technical field of nickel-hydrogen batteries, and in particular to a negative electrode plate of a nickel-hydrogen battery and a nickel-hydrogen battery. Background Art

[0002] Nickel-metal hydride (Ni-MH) batteries have the advantages of high energy density, good rate performance, environmental protection, safety and wide temperature adaptability, so they are widely used in various portable electronic devices.

[0003] The nickel-hydrogen battery of the related art has a serious limitation on the cycle life and rate performance of the nickel-hydrogen battery due to the corrosion problem of the hydrogen storage alloy of the negative electrode material, which limits the application of the nickel-hydrogen battery. The related technology improves the corrosion problem of the hydrogen storage alloy of the nickel-hydrogen battery from many aspects such as composition regulation and heat treatment process, but there are still some shortcomings, and it is difficult to meet the long cycle life and high rate performance expected by the market. Summary of the invention

[0004] In order to solve or partially solve the problems existing in the related art, the present application provides a negative electrode plate of a nickel-hydrogen battery and a nickel-hydrogen battery, which can inhibit the corrosion of the hydrogen storage alloy of the nickel-hydrogen battery negative electrode material and improve the cycle life and rate performance of the nickel-hydrogen battery.

[0005] The first aspect of the present application provides a negative electrode plate of a nickel-hydrogen battery, the negative electrode plate comprising a negative electrode current collector, a negative electrode material layer disposed on at least one side of the negative electrode current collector, and a conductive anti-corrosion layer covering the negative electrode material layer; wherein: The conductive anti-corrosion layer includes a conductive anti-corrosion alloy, and the conductive anti-corrosion alloy includes a first metal material and a second metal material. The conductivity of the first metal material is better than that of the second metal material.

[0006] Preferably, the mass ratio of the first metal material to the second metal material is m, (1 / 10)≤m≤(1 / 4).

[0007] Preferably, the thickness of the conductive anti-corrosion layer is h, 1 μm≤h≤4 μm.

[0008] Preferably, the first metal material and the second metal material meeting the mass ratio are vacuum melted to obtain an alloy ingot in which the first metal material and the second metal material are uniformly mixed; The alloy ingot is annealed under the protection of an inert gas to obtain the conductive corrosion-resistant alloy.

[0009] Preferably, the vacuum melting of the first metal material and the second metal material meeting the mass ratio to obtain an alloy ingot in which the first metal material and the second metal material are uniformly mixed comprises: The first metal material and the second metal material meeting the mass ratio are vacuum melted for a set number of times using a vacuum arc melting furnace to obtain an alloy ingot in which the first metal material and the second metal material are uniformly mixed.

[0010] Preferably, the annealing temperature of the annealing treatment is T, 900°C≤T≤1400°C, and the annealing time is t, 10 hours≤t≤48 hours.

[0011] Preferably, the conductive corrosion-resistant alloy is sputtered onto the negative electrode material layer by a sputtering process to form the conductive corrosion-resistant layer covering the negative electrode material layer.

[0012] Preferably, a sputtering process is adopted to sputter the conductive corrosion-resistant alloy onto the negative electrode material layer in a vacuum environment with a set pressure to form the conductive corrosion-resistant layer covering the negative electrode material layer; wherein the set pressure is P, 0.5Pa≤P≤3Pa.

[0013] Preferably, the first metal material is copper, and the second metal material is nickel.

[0014] A second aspect of the present application is a nickel-hydrogen battery, comprising: a positive electrode plate, a separator, and the negative electrode plate as described above.

[0015] The technical solution provided by this application may have the following beneficial effects: According to the technical solution of the present application, the negative electrode material layer of the negative electrode plate is coated with a conductive anti-corrosion layer, which has conductivity and corrosion resistance against electrolyte corrosion. The conductive anti-corrosion layer can isolate the hydrogen storage alloy and the electrolyte, protect the hydrogen storage alloy of the negative electrode material layer, reduce the contact between the hydrogen storage alloy and the electrolyte, and inhibit the side reaction between the hydrogen storage alloy and the electrolyte, thereby slowing down the corrosion of the hydrogen storage alloy, improving the electrochemical cycle stability of the hydrogen storage alloy, and increasing the service life of the hydrogen storage alloy. The "hydrogen absorption" performance of the hydrogen storage alloy is guaranteed. The conductive anti-corrosion layer can improve the conductivity of the negative electrode plate of the nickel-hydrogen battery, and can improve the cycle life and rate performance of the nickel-hydrogen battery.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the present application will become more apparent by describing in more detail exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0018] Figure 1It is a schematic cross-sectional view of the negative electrode sheet of the nickel-hydrogen battery shown in the embodiment of the present application. DETAILED DESCRIPTION

[0019] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0020] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0021] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] The embodiment of the present application provides a negative electrode plate of a nickel-hydrogen battery, which can inhibit the corrosion of the hydrogen storage alloy of the nickel-hydrogen battery negative electrode material and improve the cycle life and rate performance of the nickel-hydrogen battery.

[0023] The technical solution of the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0024] Figure 1 It is a schematic cross-sectional view of the negative electrode sheet of the nickel-hydrogen battery shown in the embodiment of the present application.

[0025] See also Figure 1 A negative electrode plate of a nickel-hydrogen battery includes a negative electrode current collector 103, a negative electrode material layer 101 disposed on at least one side of the negative electrode current collector 103, and a conductive anti-corrosion layer 102 covering the negative electrode material layer 101; wherein the conductive anti-corrosion layer 102 includes a conductive anti-corrosion alloy, the conductive anti-corrosion alloy includes a first metal material and a second metal material, and the conductivity of the first metal material is better than that of the second metal material.

[0026] In one embodiment, a conductive corrosion-resistant alloy can be prepared by using a first metal material and a second metal material with conductivity, wherein the conductivity of the first metal material is better than that of the second metal material; the conductive corrosion-resistant alloy is plated on a negative electrode plate of a suitable size for a nickel-hydrogen battery, and a uniform and dense conductive corrosion-resistant layer including the conductive corrosion-resistant alloy is plated on the negative electrode material layer of the negative electrode plate, wherein the conductive corrosion-resistant layer has conductivity and corrosion resistance against electrolyte corrosion.

[0027] In one embodiment, negative electrode materials of nickel-hydrogen batteries, such as hydrogen storage alloy powder, additives, thickeners, and adhesives, can be evenly mixed to prepare negative electrode slurry of nickel-hydrogen batteries; the negative electrode slurry of nickel-hydrogen batteries is evenly coated on the negative electrode collector, and then dried, rolled, softened, and cut to obtain negative electrode sheets of suitable sizes for nickel-hydrogen batteries.

[0028] The negative electrode plate of the nickel-hydrogen battery in the embodiment of the present application, the negative electrode material layer of the negative electrode plate is coated with a conductive anti-corrosion layer, the conductive anti-corrosion layer has conductivity and corrosion resistance against electrolyte corrosion, the conductive anti-corrosion layer can isolate the hydrogen storage alloy and the electrolyte, protect the hydrogen storage alloy in the negative electrode material layer, reduce the contact between the hydrogen storage alloy and the electrolyte, and inhibit the side reaction between the hydrogen storage alloy and the electrolyte, thereby slowing down the corrosion of the hydrogen storage alloy, improving the electrochemical cycle stability of the hydrogen storage alloy, increasing the service life of the hydrogen storage alloy, and ensuring the "hydrogen absorption" performance of the hydrogen storage alloy. The conductive anti-corrosion layer can improve the conductivity of the negative electrode plate of the nickel-hydrogen battery, and can improve the cycle life and rate performance of the nickel-hydrogen battery.

[0029] In one embodiment, a negative electrode plate of a nickel-hydrogen battery includes a negative electrode current collector, a negative electrode material layer, and a conductive anti-corrosion layer coating the negative electrode material layer stacked in sequence; wherein the conductive anti-corrosion layer can improve the conductivity of the negative electrode plate and improve the corrosion resistance of the hydrogen storage alloy of the negative electrode plate, the conductive anti-corrosion layer includes a conductive anti-corrosion alloy, the conductive anti-corrosion alloy includes a first metal material and a second metal material, and the conductivity of the first metal material is better than that of the second metal material.

[0030] In one embodiment, negative electrode materials of nickel-hydrogen batteries, such as hydrogen storage alloy powder, additives, thickeners, and adhesives, can be evenly mixed to prepare negative electrode slurry of nickel-hydrogen batteries; the negative electrode slurry of nickel-hydrogen batteries is evenly coated on the negative electrode collector, and then dried, rolled, softened, and cut to obtain negative electrode sheets of suitable sizes for nickel-hydrogen batteries.

[0031] In one embodiment, the nickel (Ni) content of the hydrogen storage alloy in the negative electrode material layer is 75 wt %-85 wt %.

[0032] In one embodiment, a first metal material and a second metal material having a certain mass ratio may be vacuum melted to obtain an alloy ingot in which the first metal material and the second metal material are uniformly mixed; the alloy ingot is annealed under the protection of an inert gas to obtain a conductive and corrosion-resistant alloy; wherein the mass ratio of the first metal material to the second metal material is m, (1 / 10)≤m≤(1 / 4), that is, m=mass of the first metal material:mass of the second metal material, (1 / 10)≤m≤(1 / 4).

[0033] In one embodiment, a vacuum arc melting furnace can be used to vacuum melt a first metal material and a second metal material that meet a mass ratio for a set number of times to obtain an alloy ingot in which the first metal material and the second metal material are evenly mixed; the alloy ingot is annealed under the protection of an inert gas to obtain a conductive and corrosion-resistant alloy; wherein the annealing temperature of the annealing treatment is T, 900°C≤T≤1400°C (degrees Celsius), and the annealing time is t, 10 hours≤t≤48 hours.

[0034] In one embodiment, a sputtering process may be used to sputter a conductive corrosion-resistant alloy onto the negative electrode material layer to form a conductive corrosion-resistant layer covering the negative electrode material layer; wherein the thickness of the conductive corrosion-resistant layer may be h, 1μm≤h≤4μm (micrometers).

[0035] In one embodiment, a sputtering process can be used to sputter a conductive corrosion-resistant alloy onto the negative electrode material layer in a vacuum environment with a set pressure to form a conductive corrosion-resistant layer covering the negative electrode material layer; wherein the set pressure is P, 0.5Pa≤P≤3Pa (Pascal, unit of pressure).

[0036] In one embodiment, a first metal material and a second metal material with a mass ratio of m and (1 / 10)≤m≤(1 / 4) can be placed in a vacuum arc melting furnace, and the temperature of the vacuum arc melting furnace can be adjusted by adjusting the output current of the vacuum arc melting furnace, and the first metal material and the second metal material can be melted completely and evenly mixed by melting the first metal material and the second metal material for a set number of times; the evenly mixed first metal material and second metal material are cooled to obtain an alloy ingot of the first metal material and the second metal material; the alloy ingot of the first metal material and the second metal material is placed in an annealing furnace with inert gas (for example, argon) protection, and the alloy ingot is annealed under the protection of the inert gas, the annealing temperature is 900°C-1400°C, the annealing time is 10h-48h (hours), and the alloy is cooled with the furnace; the prepared annealed alloy ingot is subjected to a series of mechanical processing to obtain a conductive corrosion-resistant alloy composed of the first metal material and the second metal material.

[0037] In one embodiment, during the charge and discharge process of the nickel-hydrogen battery, the first metal material and the second metal material of the conductive anti-corrosion layer of the negative electrode plate have conductivity, which can improve the conductivity of the negative electrode plate of the nickel-hydrogen battery and the rate performance of the nickel-hydrogen battery; the first metal material of the conductive anti-corrosion layer is oxidized to form an oxide during the charge and discharge process of the nickel-hydrogen battery, and the oxide can isolate the hydrogen storage alloy and the electrolyte, protect the hydrogen storage alloy of the negative electrode material layer, reduce the contact between the hydrogen storage alloy and the electrolyte, thereby slowing down the corrosion of the hydrogen storage alloy and improving the cycle life of the nickel-hydrogen battery.

[0038] In one embodiment, the first metal material may be copper, the second metal material may be nickel, and the conductive anti-corrosion alloy may be a nickel-copper alloy. To ensure the uniformity of the nickel-copper alloy, the mass of the nickel-copper alloy may be controlled at 40 g; according to the mass ratio of copper to nickel, for example, 1:4, 8 g (40 g × 10 g) may be added to the nickel-copper alloy. ) of copper, 32g (40g× ) is placed in a vacuum arc melting furnace, the temperature of the vacuum arc melting furnace is adjusted by adjusting the output current of the vacuum arc melting furnace, and the copper and nickel are smelted for a set number of times so that the two metals, copper and nickel, are completely melted and evenly mixed; the evenly mixed copper and nickel are cooled to obtain a copper-nickel alloy ingot; the copper-nickel alloy ingot is placed in an annealing furnace with inert gas (for example, argon) protection for inert gas protection annealing, the annealing temperature is 1200° C., the annealing time is 10 hours, and the ingot is cooled with the furnace to obtain an annealed nickel-copper alloy ingot; the prepared annealed nickel-copper alloy ingot is subjected to a series of mechanical processing to obtain 40g of conductive and corrosion-resistant nickel-copper alloy.

[0039] In one embodiment, a sputtering process can be adopted through magnetron sputtering equipment to sputter a conductive corrosion-resistant alloy onto the negative electrode material layer in a vacuum environment with a set pressure, and a uniform and dense layer of conductive corrosion-resistant alloy is coated on the negative electrode material layer to form a conductive corrosion-resistant layer covering the negative electrode material layer; wherein the set pressure is 0.5Pa-3Pa.

[0040] In one embodiment, a nickel-copper alloy can be installed as a target material on a magnetron sputtering device, and a negative electrode piece can be placed in a magnetron sputtering reaction chamber of the magnetron sputtering device. The reaction chamber is evacuated by a mechanical pump and a molecular pump until the vacuum degree of the reaction chamber reaches 7×10 -4After 300 Pa, high-purity argon gas is introduced, and then vacuuming and filling with argon are repeated three times to ensure that there is no residual air in the reaction chamber; then the vacuum valve is adjusted to adjust the vacuum degree in the reaction chamber to the set pressure; after the vacuum degree of the reaction chamber is stable, the pulse bias power supply of the magnetron sputtering equipment is turned on, and the voltage is adjusted to 100V (volts) -400V to pre-sputter the surface of the negative electrode material layer of the negative electrode plate to remove the surface active material oxide layer of the negative electrode material layer of the negative electrode plate and the gas adsorbed on the surface; after the pre-sputtering is completed, the voltage is continued to be adjusted to 10 V-80V, turn on the RF power supply and the RF power adapter at the same time, then adjust the RF power to 200W (watt) -400W, then start the panel to start sputtering nickel-copper alloy onto the negative electrode material layer of the negative electrode plate, and uniformly coat the nickel-copper alloy on the negative electrode material layer of the negative electrode plate. The coating time is 50min-100min (minutes), and a layer of uniform and dense nickel-copper film with a thickness of 1μm-4μm is coated on the surface of the negative electrode material layer. The nickel-copper film is the conductive and corrosion-resistant layer of the negative electrode plate of the nickel-hydrogen battery.

[0041] The negative electrode plate of the nickel-hydrogen battery in the embodiment of the present application adopts a sputtering process, with a conductive corrosion-resistant alloy as a target material, and a uniform and dense conductive corrosion-resistant alloy is plated on the negative electrode material layer of the negative electrode plate to form a conductive corrosion-resistant layer covering the negative electrode material layer. The conductive corrosion-resistant layer has conductivity and corrosion resistance against electrolyte corrosion. The conductive corrosion-resistant layer can isolate the hydrogen storage alloy and the electrolyte, protect the hydrogen storage alloy in the negative electrode material layer, reduce the contact between the hydrogen storage alloy and the electrolyte, and inhibit the side reaction between the hydrogen storage alloy and the electrolyte, thereby slowing down the corrosion of the hydrogen storage alloy, improving the electrochemical cycle stability of the hydrogen storage alloy, and improving the service life of the hydrogen storage alloy. The "hydrogen absorption" performance of the hydrogen storage alloy is guaranteed. The conductive corrosion-resistant layer can improve the conductivity of the negative electrode plate of the nickel-hydrogen battery, and can improve the cycle life and rate performance of the nickel-hydrogen battery.

[0042] The negative electrode plate of the nickel-hydrogen battery in the embodiment of the present application, the conductive and corrosion-resistant alloy is a copper-nickel alloy, During the charge and discharge process of nickel-hydrogen batteries, the positive electrode is overcharged and oxygen evolution side reaction occurs. The released oxygen is transferred to the negative electrode and absorbed. Copper is easily corroded in an alkaline, oxygen-rich environment, forming a copper oxide passivation layer. This passivation layer is relatively dense and can effectively prevent further corrosion of the alloy inside the negative electrode (hydrogen storage alloy). Copper has excellent conductivity and can greatly increase the transfer rate of electrons at the negative electrode interface under mild corrosion conditions. After strong corrosion occurs to form copper oxide and lose conductivity, the nickel of the copper-nickel alloy, which is not easily corroded in oxygen-rich acid and alkali environments and has strong conductivity, can play a conductive role. During the charge and discharge process of nickel-metal hydride batteries, the copper and nickel of the copper-nickel alloy have electrical conductivity and corrosion resistance against electrolyte corrosion. The copper oxide formed by the copper of the copper-nickel alloy can isolate the hydrogen storage alloy and the electrolyte, protect the hydrogen storage alloy in the negative electrode material layer, reduce the contact between the hydrogen storage alloy and the electrolyte, and inhibit the side reaction between the hydrogen storage alloy and the electrolyte, thereby slowing down the corrosion of the hydrogen storage alloy, improving the electrochemical cycle stability of the hydrogen storage alloy, and increasing the service life of the hydrogen storage alloy. Ensure the "hydrogen absorption" performance of the hydrogen storage alloy, the conductive effect of the copper and nickel of the copper-nickel alloy can improve the conductive performance of the negative electrode sheet of the nickel-metal hydride battery, and can improve the cycle life and rate performance of the nickel-metal hydride battery.

[0043] In addition, an embodiment of the present application further provides a nickel-hydrogen battery, which includes a positive electrode plate, a separator, and the above-mentioned negative electrode plate.

[0044] In one embodiment, the positive electrode plate of the nickel-hydrogen battery includes nickel hydroxide coated with trivalent cobalt.

[0045] In one embodiment, the diaphragm of the nickel-hydrogen battery is treated with sulfonation and has a surface density of 60 g / cm 3 (grams per cubic centimeter) -70g / cm 3 of non-woven fabric.

[0046] The negative electrode sheet of the nickel-hydrogen battery of the embodiment of the present application is described below with reference to comparative examples and embodiments 1-9.

[0047] According to the battery parameters of the nickel-hydrogen battery, the positive electrode sheet, the separator, and the negative electrode sheet of the embodiment and the comparative example are cut to obtain suitable sizes.

[0048] Comparative Example: In the comparative example, the negative electrode materials of the nickel-hydrogen battery such as hydrogen storage alloy powder, additives, thickeners, and adhesives can be mixed evenly to prepare the negative electrode slurry of the nickel-hydrogen battery; the negative electrode slurry of the nickel-hydrogen battery is evenly coated on the negative electrode current collector, and then dried, rolled, softened, and cut to obtain the negative electrode pole piece of the nickel-hydrogen battery of suitable size; the positive electrode slurry of the nickel-hydrogen battery is prepared according to the positive electrode material including nickel hydroxide coated with trivalent cobalt; the positive electrode slurry of the nickel-hydrogen battery is evenly coated on the positive electrode current collector, and then dried, rolled, softened, and cut to obtain the positive electrode pole piece of the nickel-hydrogen battery of suitable size; the positive pole piece, the negative pole piece, and the diaphragm are stacked into a pole group, which is sealed in a battery shell and injected with electrolyte. After formation, a nickel-hydrogen battery B is obtained.

[0049] Embodiment 1-9: The preparation of the positive electrode sheet, negative electrode sheet, separator and electrolyte of the nickel-hydrogen battery in Examples 1-9 is the same as that of the comparative example, and the difference from the comparative example is that: In Example 1, the negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery A1 has a conductive anti-corrosion layer. The mass ratio of copper to nickel in the conductive anti-corrosion alloy of the conductive anti-corrosion layer is 1:4, and the thickness of the conductive anti-corrosion layer is 1 μm.

[0050] In Example 2, the negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery A2 has a conductive anti-corrosion layer. The mass ratio of copper to nickel in the conductive anti-corrosion alloy of the conductive anti-corrosion layer is 1:4, and the thickness of the conductive anti-corrosion layer is 1.5 μm.

[0051] The negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery A3 of Example 3 has a conductive anti-corrosion layer. The mass ratio of copper to nickel in the conductive anti-corrosion alloy of the conductive anti-corrosion layer is 1:4, and the thickness of the conductive anti-corrosion layer is 2 μm.

[0052] Example 4 The negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery A4 has a conductive anti-corrosion layer. The mass ratio of copper to nickel in the conductive anti-corrosion alloy of the conductive anti-corrosion layer is 1:4, and the thickness of the conductive anti-corrosion layer is 4 μm.

[0053] The negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery A5 of Example 5 has a conductive anti-corrosion layer. The mass ratio of copper to nickel in the conductive anti-corrosion alloy of the conductive anti-corrosion layer is 1:1, and the thickness of the conductive anti-corrosion layer is 1 μm.

[0054] The negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery A6 of Example 6 has a conductive anti-corrosion layer. The mass ratio of copper to nickel in the conductive anti-corrosion alloy of the conductive anti-corrosion layer is 1:2, and the thickness of the conductive anti-corrosion layer is 1 μm.

[0055] The negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery A7 of Example 7 has a conductive anti-corrosion layer. The mass ratio of copper to nickel in the conductive anti-corrosion alloy of the conductive anti-corrosion layer is 1:6, and the thickness of the conductive anti-corrosion layer is 1 μm.

[0056] In Example 8, the negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery A8 has a conductive anti-corrosion layer. The mass ratio of copper to nickel in the conductive anti-corrosion alloy of the conductive anti-corrosion layer is 2:1, and the thickness of the conductive anti-corrosion layer is 1 μm.

[0057] The negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery A9 of Example 9 has a conductive anti-corrosion layer. The mass ratio of copper to nickel in the conductive anti-corrosion alloy of the conductive anti-corrosion layer is 4:1, and the thickness of the conductive anti-corrosion layer is 1 μm.

[0058] The nickel-hydrogen batteries A1-A9 of Examples 1-9 and the nickel-hydrogen battery B of the comparative example were subjected to cycle life tests under the same cycle life test conditions and rate performance tests under the same rate performance test conditions, and the test data shown in Tables 1 and 2 were obtained.

[0059] Cycle life is measured by 1C accelerated life test. Taking the 2A1200 model as an example, the actual capacity of the battery is 1250mAh, so 1C is 1250mAh. Cycle life is expressed by SOH, that is, SOH=C 300 / C ICE *100%, of which C 300 is the discharge capacity at 300 cycles, C IEC The battery was charged at 0.1C for 16h and discharged at 0.2C to maximum capacity.

[0060] The rate performance test is expressed in SOC, that is, SOC=C 5C / C IEC *100%, of which C 5C The battery was cycled 300 times, charged at 0.1C for 16h, and discharged at 5C.

[0061] According to the comparative examples in Table 1 and Table 2 and the test data of Examples 1-9, the negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery in Examples 1-9 has a conductive anti-corrosion layer, and the conductive anti-corrosion layer has conductivity and corrosion resistance against electrolyte corrosion. The conductive anti-corrosion layer can isolate the hydrogen storage alloy and the electrolyte, protect the hydrogen storage alloy of the negative electrode material layer, reduce the contact between the hydrogen storage alloy and the electrolyte, and inhibit the side reaction between the hydrogen storage alloy and the electrolyte, thereby slowing down the corrosion of the hydrogen storage alloy, improving the electrochemical cycle stability of the hydrogen storage alloy, and improving the service life of the hydrogen storage alloy. The "hydrogen absorption" performance of the hydrogen storage alloy is guaranteed, and the conductive anti-corrosion layer can improve the conductivity of the negative electrode plate of the nickel-hydrogen battery, and can improve the cycle life and rate performance of the nickel-hydrogen battery.

[0062] According to the test data of Examples 1-4 in Table 1, the negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery of Examples 1-4 has a conductive anti-corrosion layer. The thicker the conductive anti-corrosion layer, the better the conductivity and corrosion resistance of the conductive anti-corrosion layer against electrolyte corrosion, and the more the cycle life and rate performance of the nickel-hydrogen battery can be improved.

[0063] According to the test data of Examples 5-9 in Table 2, the negative electrode material layer of the negative electrode plate of the nickel-hydrogen battery of Examples 5-9 has a conductive anti-corrosion layer. The higher the proportion of copper in the conductive anti-corrosion layer, the better the corrosion resistance of the conductive anti-corrosion layer against electrolyte corrosion, and the better the cycle life of the nickel-hydrogen battery; the higher the proportion of nickel in the conductive anti-corrosion layer, the better the conductivity of the negative electrode plate of the nickel-hydrogen battery, and the better the rate performance of the nickel-hydrogen battery.

[0064] Table 1:

[0065] Table 2:

[0066] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A negative electrode plate for a nickel-hydrogen battery, characterized in that: It comprises a negative electrode current collector, a negative electrode material layer disposed on at least one side of the negative electrode current collector, and a conductive anti-corrosion layer covering the negative electrode material layer; wherein, The conductive anti-corrosion layer includes a conductive anti-corrosion alloy, and the conductive anti-corrosion alloy includes a first metal material and a second metal material. The conductivity of the first metal material is better than that of the second metal material.

2. The negative electrode sheet according to claim 1, characterized in that: The mass ratio of the first metal material to the second metal material is m, (1 / 10)≤m≤(1 / 4).

3. The negative electrode sheet according to claim 1, characterized in that: The thickness of the conductive anti-corrosion layer is h, 1 μm≤h≤4 μm.

4. The negative electrode sheet according to claim 2, characterized in that: Vacuum melting the first metal material and the second metal material in the mass ratio to obtain an alloy ingot in which the first metal material and the second metal material are uniformly mixed; The alloy ingot is annealed under the protection of an inert gas to obtain the conductive corrosion-resistant alloy.

5. The negative electrode sheet according to claim 4, characterized in that: The vacuum melting of the first metal material and the second metal material meeting the mass ratio to obtain an alloy ingot in which the first metal material and the second metal material are uniformly mixed comprises: The first metal material and the second metal material meeting the mass ratio are vacuum melted for a set number of times using a vacuum arc melting furnace to obtain an alloy ingot in which the first metal material and the second metal material are uniformly mixed.

6. The negative electrode plate according to claim 4, characterized in that: The annealing temperature of the annealing treatment is T, 900° C.≤T≤1400° C., and the annealing time is t, 10 hours≤t≤48 hours.

7. The negative electrode sheet according to claim 1, characterized in that: The conductive corrosion-resistant alloy is sputtered onto the negative electrode material layer by a sputtering process to form the conductive corrosion-resistant layer covering the negative electrode material layer.

8. The negative electrode plate according to claim 7, characterized in that: The conductive corrosion-resistant alloy is sputtered onto the negative electrode material layer in a vacuum environment with a set pressure by using a sputtering process to form the conductive corrosion-resistant layer covering the negative electrode material layer; wherein the set pressure is P, 0.5Pa≤P≤3Pa.

9. The negative electrode sheet according to any one of claims 1 to 8, characterized in that: The first metal material is copper, and the second metal material is nickel.

10. A nickel-metal hydride battery, characterized in that: include: A positive electrode sheet, a separator, and a negative electrode sheet as claimed in any one of claims 1 to 9.

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