An electrode sheet and a secondary battery

Abstract

The application discloses an electrode sheet and a secondary battery, and belongs to the technical field of batteries. The electrode sheet comprises an active substance and a current collector, and the secondary battery comprises the electrode sheet. The current collector is a porous metal with an open framework, and the porous metal is composed of a metal framework and pores. The metal framework is all open framework or a mixture of open framework and hollow framework. By opening the closed space in most or all of the hollow framework of the porous metal, the surface area is increased, the effective porosity is improved, and thus the battery capacity is improved. Meanwhile, the electrolyte or the electrode active substance can have a larger contact area with the current collector, and the battery has a smaller internal resistance, so that the battery has better charge and discharge characteristics.

Description

[0001] This application claims priority to Chinese invention application No. 2022114904608, filed on November 25, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention belongs to the field of battery technology and relates to an electrode sheet and a secondary battery. Background Technology

[0003] Electrochemical energy storage technology, exemplified by rechargeable batteries, is widely used in portable consumer electronics and plays a crucial role in promoting the development of electric vehicles and the storage and conversion of renewable energy. This not only alleviates the environmental pollution pressures currently facing my country and reduces the use of primary energy sources, but also allows for the rational allocation of intermittent new energy sources (such as wind and solar power), promoting the positive role of renewable energy in human society. With the increasing demands for energy density and power density in energy storage systems, as well as the technological requirements of new fields, the search for new materials, the research of new energy storage mechanisms, and the construction of new device structures have become hot topics in the global electrochemical field.

[0004] In principle, a typical electrochemical system includes electrode materials and an electrolyte. Energy storage and release in a secondary battery rely on the reactions of ions and electrons at the electrodes; the electrochemical properties of the electrodes directly determine the electrochemical performance of the capacitor or lithium-ion battery. Therefore, breakthroughs in electrode materials and structures, along with a deeper understanding of the corresponding electrochemical mechanisms, are prerequisites for significant advancements in battery technology.

[0005] Electrode materials generally consist of active materials, conductive agents, and binders. These three components are uniformly coated onto a conductive current collector to form the electrode material. The current collector collects the current generated by the active material during charging and discharging and transfers it to the load through an external circuit. In recent years, with the changing demands of energy storage devices, many new requirements have also arisen for current collectors.

[0006] Due to their high porosity and large specific surface area, porous metals can accommodate more active materials, increasing battery capacity and significantly reducing the actual current density of the electrodes. They are ideal materials for manufacturing electrodes for various primary and secondary batteries, including nickel-cadmium, nickel-metal hydride, vanadium, nickel-zinc, sodium-ion, and lithium-ion batteries, as well as for storage batteries, air batteries, fuel cells, and solar cells. This makes it possible to develop lightweight batteries with low internal consumption, long lifespan, and high specific energy. Porous metals also possess good electrical conductivity, a certain degree of self-support, and a large specific surface area to provide ample space for interfacial electrochemical charge transfer, thus becoming excellent electrode materials.

[0007] Lithium-ion battery anodes are prone to lithium dendrite formation and significant volume expansion during lithium insertion / extraction processes during cycling. Numerous researchers have proposed various solutions, among which constructing three-dimensional porous current collectors as the primary lithium intercalation substrate has become a research hotspot in recent years. The ultra-large specific surface area provided by three-dimensional porous current collectors can effectively reduce the current density during charging and discharging, allowing lithium-ion deposition to proceed relatively slowly and providing more nucleation sites. This mitigates the formation of dendritic lithium and dead lithium, as well as the significant volume changes during lithium insertion / extraction.

[0008] Nickel foam is a typical porous metal. As an electroforming replica of organic foam plastics, it largely retains the original foam plastic's structural morphology. The framework of nickel foam is crisscrossed, with each node typically formed by 3-5 intersecting framework members. After the organic foam matrix is ​​removed, these metal frameworks form tiny hollow cavities within them. These tiny hollow cavities are the spaces left after the original organic foam plastic disappears. Therefore, the framework is a closed, hollow prismatic structure. The tiny hollow cavities inside the framework are also part of the overall porosity of nickel foam, accounting for approximately 2% to 20% of the total porosity. These pores located inside the framework are too small to easily fill with active materials and also increase the battery's resistivity. If these micropores can be utilized during battery manufacturing, the amount of electrolyte or electrode active material can be increased, thereby improving the battery's overall performance.

[0009] Porous metals with hollow prisms have a framework of tiny hollow cavities, the inner walls of which also have a large surface area. However, because they are enclosed within the framework, this surface area is difficult to utilize. If a way could be found to expose this surface area, when such porous metals are used as battery current collectors, the electrolyte or electrode active materials could have a larger contact area with the current collector. This would significantly improve the current collection capacity and enhance the overall battery performance.

[0010] The production process of hollow prismatic porous metal by depositing metal on an organic porous template and then sintering and reducing it has the advantages of convenient large-scale continuous production, lower cost and better consistency compared with other porous metal manufacturing processes. These advantages are unmatched by porous metals manufactured by other processes. However, the disadvantage of porous metals prepared by this template method is that the metal skeleton is hollow. The hollow cavities inside the skeleton occupy a lot of voids that are almost unusable, making it difficult to fully realize the advantages of this type of porous metal. Therefore, it is necessary to open up the closed hollow prismatic structure and utilize the voids and surface area it occupies to improve the performance of secondary batteries. Summary of the Invention

[0011] The purpose of this invention is to provide a novel electrode sheet and a technical solution and corresponding product for a secondary battery, using a porous metal with an open framework as the electrode current collector of the secondary battery. The porous metal with an open framework used in this invention can open most or all of the closed spaces within the hollow framework of the porous metal, increasing the surface area, reducing density, and improving the effective porosity, thereby further releasing the potential performance of the porous metal and improving the overall performance of the battery. The effective porosity refers to the proportion of pores that can perform functions (filling electrode active materials, absorbing electrolyte, acting as ion channels, etc.) to the total pores. The purpose of this invention is achieved through the following technical solution.

[0012] An electrode sheet includes an active material and a current collector; The active material is formed on the surface of the current collector, or on both sides of the current collector, or in the internal pores of the current collector; The current collector is a porous metal with an open framework. The porous metal is composed of a metal framework and pores. The metal framework is obtained by depositing metal on the surface of an organic polymer porous material and then removing the organic polymer porous material. The metal framework is entirely an open framework or a mixture of an open framework and a hollow framework. The open framework includes the space left after the metal deposition layer and the organic polymer porous material are removed. The space left is not completely surrounded by the metal deposition layer and can be directly connected to the external space. The hollow framework includes the space left after the metal deposition layer and the organic polymer porous material are removed. The space left is completely surrounded by the metal deposition layer and cannot be directly connected to the external space.

[0013] Furthermore, the active material is a positive electrode active material or a negative electrode active material.

[0014] Furthermore, the open frame accounts for 20% to 100% of the total metal frame, preferably 80% to 100%.

[0015] The proportion of open skeletons to all metal skeletons described in this invention can be measured by the following method: Take a piece of porous metal, encapsulate it in resin (e.g., epoxy resin), and then polish the test surface. The test surface can be any one of the four surfaces parallel to the direction of directional metal deposition. After polishing the test surface, select a test area on the test surface with a width equal to the thickness of the porous metal and a length equal to twice the thickness of the porous metal. Calculate the number of open skeletons in the test area and the total number of metal skeletons. If a part of an open skeleton or hollow skeleton is included in the test area, it is considered as one open skeleton or hollow skeleton and accumulated.

[0016] The proportion of open frames to all metal frames = total number of open frames in the test area ÷ total number of all metal frames in the test area × 100%.

[0017] In some specific embodiments, the porous metal is a two-dimensional porous metal, whose metal skeleton is a continuous solid arranged in a polygonal two-dimensional pattern; correspondingly, the pores are columnar and separated between the metal skeleton.

[0018] In some specific embodiments, the porous metal is a three-dimensional porous metal, whose metal skeleton is a continuous solid with a three-dimensional network structure, and the pores between the metal skeletons are interconnected.

[0019] In some specific embodiments, the average pore diameter is 0.05 to 5 mm.

[0020] In some specific embodiments, the thickness of the metal layer of the metal skeleton is 1 to 1000 μm.

[0021] In some specific embodiments, the thickness of the porous metal is 0.005 to 65 mm.

[0022] In some specific embodiments, the metal deposition layer is a dual-mode metal deposition layer composed of two different sizes of grains or a multi-mode metal deposition layer composed of multiple different sizes of grains.

[0023] In some specific embodiments, the metal deposition layer is a single metal material formed from any one of iron, nickel, copper, iron, aluminum, chromium, cadmium, germanium, tin, lead, zinc, gold, silver, titanium, cobalt, vanadium, niobium, hafnium, tantalum, bismuth, molybdenum, tungsten, manganese, platinum, palladium, ruthenium, rhodium, iridium, and osmium, or a multilayer metal material or alloy material formed from two or more of the above metals.

[0024] The present invention also provides a secondary battery, comprising an anode plate, a cathode plate, a separator spaced between the anode plate and the cathode plate, and an electrolyte, wherein the anode plate and / or the cathode plate uses the aforementioned electrode plates.

[0025] Furthermore, the secondary battery is a lithium-ion secondary battery, a sodium-ion secondary battery, a zinc-ion secondary battery, a nickel-ion secondary battery, or a nickel-zinc battery.

[0026] For the preparation method of porous metal with an open framework and the morphology of the open framework and the hollow framework involved in this invention, please refer to Chinese Invention Application No. 2023100140947 entitled "Porous Metal with Open Framework and Manufacturing Method Thereof".

[0027] The electrode sheet provided by this invention uses a porous metal current collector with an open framework. Since over 20% of its framework is open, the previously unusable inner surface of the cavity becomes an effective outer surface, significantly increasing the surface area of ​​the porous metal and its effective porosity. When used as a battery current collector, this space can be used to fill more electrolyte or electrode active material, thereby increasing battery capacity. Simultaneously, the electrolyte or electrode active material can have a larger contact area with the current collector, resulting in lower internal resistance and better overall battery performance, including improved charge / discharge characteristics.

[0028] Nickel-metal hydride (NiMH) batteries are a type of secondary battery that uses porous metal current collectors, but their electrochemical performance has not seen substantial improvement over the years. The ever-growing energy storage market demands better performance from NiMH batteries, especially higher energy density. The current collector is another indispensable component besides the electrode material, serving multiple functions including material support, electronic conductor, and current collection. Therefore, the current collector has a significant impact on the structure and electrochemical performance of NiMH batteries. Preparing current collectors with suitable porous structures (such as porosity and pore structure) is a crucial way to improve their performance. Suitable porous structures can increase specific surface area, facilitate electrolyte wetting of electrode materials, reduce ohmic impedance, and increase the utilization rate of active materials. Compared to the foamed nickel current collectors currently used in NiMH batteries, the porous metal with an open framework used in this invention has higher porosity, allowing it to carry more active material when used in battery electrode manufacturing, thus increasing the battery's volumetric energy density and gravimetric energy density. Simultaneously, due to the increased specific surface area, it facilitates electrolyte wetting of electrode materials, reduces ohmic impedance, and increases the utilization rate of active materials. Other nickel-ion batteries, as well as zinc-ion secondary batteries and nickel-zinc batteries, can also have their battery performance improved by using the porous metal with an open framework provided by this invention as the current collector, as described above.

[0029] For lithium-ion or sodium-ion batteries, using porous metals with an open framework as current collectors has the following advantages: (1) It has a uniform electric field distribution, which can induce uniform deposition of lithium ions or sodium ions; (2) The porous metal framework has a stronger lithium / sodium adsorption capacity, which promotes the deposition of lithium or sodium ions on the framework and avoids the drawback of uneven deposition on the plane. (3) It provides a larger specific surface area, which can effectively reduce the current density during charging and discharging, allowing the deposition of lithium or sodium ions to proceed relatively slowly, and provides more nucleation sites, thereby alleviating the formation of dendrites and the huge volume change during the lithium (or sodium) insertion / extraction process.

[0030] (4) The pores inside the porous metal hinder dendrite growth to a certain extent, and the negative electrode support structure can withstand the mechanical damage caused by the volume change of the active material during charging and discharging. Therefore, using three-dimensional porous metal as the current collector of the electrode material can greatly improve the stability of the material during charging and discharging.

[0031] This invention offers the following beneficial technical effects: It discloses an electrode sheet using a porous metal material with ultra-high effective porosity. This porous metal with ultra-high effective porosity is manufactured using a template method, opening up the closed spaces within the metal framework. Compared to porous metals manufactured using ordinary template methods, the product of this invention possesses higher effective porosity and specific surface area, and also has lower bulk density. Its higher specific surface area provides a wider interfacial electrochemical charge transfer space, and its higher effective porosity accommodates active materials, improving energy density. Furthermore, when applied to lithium-ion / sodium-ion batteries, it can buffer the volume changes of the active material during charge and discharge, thus becoming a superior electrode current collector material. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the nickel-metal hydride battery structure in Example 1.

[0033] Figure 2 This is a schematic diagram of the soft-pack lithium-ion battery structure in Example 2. Implementation

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention. Example 1

[0035] In this embodiment, the performance of a novel electrode sheet provided by the present invention and a nickel-metal hydride battery using the electrode sheet is compared with that of a conventional nickel-metal hydride battery made entirely of foam metal with a hollow framework. The manufacturing method of the nickel-metal hydride battery used for comparison in this embodiment includes the following steps: (1) Fabrication of nickel electrode sheets: (1-1) Preparation of positive electrode active material: Using the complexation precipitation method, in the presence of 2.0 mol / L ammonia water, a 2.0 mol / L sodium hydroxide solution and a certain concentration of nickel sulfate, zinc sulfate and cobalt sulfate mixed salt solution are mixed and reacted under stirring. The concentration of nickel ions in the mixed salt solution is 0.911 mol / L, the concentration of zinc ions is 0.057 mol / L, and the concentration of cobalt ions is 0.032 mol / L. The pH value is controlled at 8-11, the reaction temperature is 40-70℃, the reaction time is 12-14 h, and the aging time is 12-14 h. A green precipitate is obtained. The reaction solution is poured off, allowed to stand and separate into layers. After the upper clear layer is poured off, it is washed with distilled water and dried at 120℃ until the water content is ≤0.5%, thus obtaining the positive electrode active material. (1-2) The positive electrode active material prepared in step (1-1) is 90.4% by weight, cobalt oxide 6.0%, calcium fluoride 1.0%, sodium carboxymethyl cellulose 0.2%, and polytetrafluoroethylene 2.4%. An appropriate amount of pure water is added and mixed evenly in a mixer to form a slurry. The slurry is then filled into a porous nickel current collector using a wet slurry-pulling process. The portion 1.5 mm from the top of the porous nickel current collector is left unfilled. After drying, the material is rolled. The above-mentioned filling material and the porous nickel current collector together form a nickel electrode with a thickness controlled at 0.37 ± 0.01 mm. The porous nickel portion without filling material is a reserved porous nickel portion, which is cut to the required size to form the desired nickel electrode.

[0036] (2) Fabrication of hydrogen electrode sheets: According to the hydrogen storage alloy powder (expression is MLNi) 3.55 Co 0.75 Mn 0.4 Al 0.3 The hydrogen storage alloy powder B, ML (a La-rich mixed rare earth element composed of La, Ce, Pr, and Nd) 93.6%, nickel powder 2.2%, yttrium oxide 1.0%, and yttrium oxide 1.0% by weight, are mixed with an appropriate amount of pure water in a mixer to form a slurry. The slurry is then coated onto a porous nickel current collector using a wet slurry coating process, leaving a 0.5mm section from the bottom of the porous nickel current collector uncoated. After drying, the material is rolled. The coating material and the porous nickel current collector together form a hydrogen electrode with a thickness controlled at 0.26±0.01mm. The unfilled portion of the porous nickel current collector is a reserved white edge, which is then cut to the required size to form the desired negative electrode sheet.

[0037] (3) Preparation of electrolyte: A solution with a density of 1.30–1.35 g / cm³ was prepared using potassium hydroxide, sodium hydroxide, and lithium hydroxide. 3 OH -An aqueous solution with a molar concentration of 8.7 mol / L is cooled to room temperature, and then sodium tungstate or tungstate crystals are added, with the concentration controlled at 0.05 mol / L. The solution is stirred continuously until it is completely dissolved, thus preparing an alkaline electrolyte containing sodium tungstate or tungstate.

[0038] (4) The diaphragm is made of polypropylene 700 / 70 with high alkali absorption, good air permeability and strong alkali resistance, which is treated with carboxyl grafting. The thickness is 0.15±0.01mm.

[0039] (5) Battery assembly: such as Figure 1 As shown, the nickel electrode, hydrogen electrode, and separator prepared in steps (1) and (2) are wound into a core 11 and implanted into a steel shell 12. The pre-reserved porous nickel current collector portion on the nickel electrode protrudes from the upper end of the separator and is connected to the battery cap 14 through the current collector plate 13. The pre-reserved white edge portion on the hydrogen electrode protrudes from the lower end of the separator and is connected to the bottom of the steel shell 12 through the porous nickel bottom pad 15. The current collector plate 300 is a nickel-plated steel sheet with a thickness of 0.2 mm. The porous nickel bottom pad 15 has a thickness of 0.6 mm, is circular in shape, and has the same area as the bottom of the steel shell 12. It is pre-placed at the bottom of the steel shell 12 by spot welding. The electrolyte prepared in step (3) is injected according to the battery capacity. The amount of electrolyte added to each battery is 2.4 g / Ah. The battery is then sealed to produce a nickel-hydrogen battery.

[0040] In one of the nickel-metal hydride batteries in this embodiment (hereinafter referred to as nickel-metal hydride 1), the nickel electrode and the porous nickel current collector in the hydrogen electrode are both made of a three-dimensional porous metal with an open framework. It is composed of an open framework and a hollow framework. The open framework accounts for 60% of the total metal framework. The overall thickness of the three-dimensional porous metal is 1.7 mm, the average pore size is 400 μm, the metal layer thickness of the metal framework is 20 μm, and the metal framework is made of pure nickel.

[0041] In this embodiment, another nickel-metal hydride battery (hereinafter referred to as nickel-metal hydride 2) uses foamed nickel composed of a hollow skeleton in both its nickel electrode and hydrogen electrode porous nickel current collector. The hollow skeleton accounts for 100% of the total metal skeleton. The overall thickness of the foamed nickel is 1.7 μm, the average pore size is 400 μm, the metal layer thickness of its metal skeleton is 200 μm, and the skeleton of the foamed nickel is composed of pure nickel.

[0042] The test results of the capacity, discharge time at different discharge rates, and high-rate capability of the nickel-metal hydride battery in this embodiment are shown in Table 1.

[0043] Table 1. Performance comparison of nickel-metal hydride batteries made with different electrode sheets

[0044] The experimental results show that the electrode sheet provided by this invention, when used to manufacture nickel-metal hydride batteries, has better capacity and high-rate discharge performance than traditional nickel-metal hydride batteries that use ordinary foamed nickel to make electrode sheets. Example 2

[0045] In this embodiment, the performance of a novel electrode sheet provided by the present invention and a lithium-ion battery using the electrode sheet are compared with that of a conventional lithium-ion battery made entirely of hollow metal foam. The manufacturing method of the lithium-ion battery used for comparison in this embodiment includes the following steps: A positive electrode slurry with certain stability and fluidity is prepared by mixing ternary NCM523 material, conductive carbon black, and polyvinylidene fluoride in a ratio of 94%:3%:3%, and adding a certain mass of N-methylpyrrolidone (NMP) at 70% solid content using a wet high-dispersion mixing method. Similarly, a negative electrode slurry with certain stability and fluidity is prepared by mixing artificial graphite, conductive carbon black, styrene-butadiene rubber, and sodium carboxymethyl cellulose in a ratio of 92%:3%:3%:2%, and adding a certain mass of deionized water at 50% solid content using a wet high-dispersion mixing process. The positive and negative electrode slurries prepared above were coated onto a 3.5 mm thick aluminum foam with a pore size of about 100 μm by transfer coating, according to a suitable N / P ratio. After infrared drying, the slurry was rolled to a thickness of 0.446 ± 0.005 mm to obtain the positive electrode sheet. The negative electrode slurry was coated onto a porous metal current collector with a thickness of 4.2 mm and a pore size of about 500 μm. After infrared drying, the negative electrode sheet was rolled to a thickness of 0.503 ± 0.005 mm to obtain the negative electrode sheet.

[0046] The positive and negative electrode sheets obtained by the above method are cut into pieces to obtain positive electrode sheets with dimensions of (137±0.5) mm × (80.5±0.5) mm and negative electrode sheets with dimensions of (141±0.5) mm × (84.5±0.5) mm. The separator sheet has a width of 90±0.5 mm. These sheets are then assembled using a stacking method to obtain a lithium battery with a positive electrode-separator-negative electrode configuration. The positive and negative electrode tabs are then welded, and the battery is encapsulated, filled with electrolyte, and sealed to finally obtain a soft-pack lithium battery. Figure 2 As shown, the battery includes a positive electrode 21, a negative electrode 22, a separator 23, a positive electrode tab 24, a negative electrode tab 25, and an aluminum-plastic packaging film 26.

[0047] In this embodiment, one group of lithium-ion batteries (hereinafter referred to as lithium battery 1) uses a three-dimensional porous metal with an open framework in its negative electrode sheet. The porous metal current collector is composed of an open framework and a hollow framework. The open framework accounts for 95% of the total metal framework. The overall thickness of the three-dimensional porous metal is 4.2 mm, and the average pore size is 500 μm. The framework of the porous metal consists of a pure nickel substrate and a copper film layer deposited on the surface of the nickel framework. The thickness of the nickel substrate layer is 11 μm, and the thickness of the copper film layer is 400 nm.

[0048] In this embodiment, another set of lithium-ion batteries (hereinafter referred to as lithium battery 2) uses foamed copper with a hollow skeleton in the porous metal current collector of the negative electrode sheet. The hollow skeleton accounts for 100% of the total metal skeleton. The overall thickness of the foamed copper is 4.2 mm, the average pore size is 500 μm, the metal layer thickness of the metal skeleton is 11 μm, and the skeleton of the foamed copper is made of pure copper.

[0049] The lithium batteries prepared in this embodiment, lithium battery 1 and lithium battery 2, were subjected to electrical performance tests. The operating voltage range was 2.8V to 4.3V. The 1 / 3C discharge capacity and the DC internal resistance at 3C room temperature with 50% SOC were tested. The electrical performance test data are compared in Table 2.

[0050] Table 2. Performance comparison of lithium batteries made with different electrode sheets

[0051] As shown in Table 2, compared with the lithium-ion battery (lithium battery 2) that uses traditional foamed copper as the current collector, the lithium-ion battery (lithium battery 1) that uses a three-dimensional porous metal with an open framework provided by the present invention as the current collector has an increased volumetric energy density of about 11%, and a reduced DC internal resistance of about 10% compared with the comparative example, and also has a significant improvement in cycle performance.

[0052] Although embodiments of the present invention have been shown and described above, it is understood that these embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and alterations to the above embodiments within the scope of the present invention without departing from its principles and spirit. The scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. An electrode sheet, characterized in that, The electrode sheet includes an active material and a current collector; The active material is formed on the surface of the current collector, or on both sides of the current collector, or in the internal pores of the current collector; The current collector is a porous metal with an open framework. The porous metal is composed of a metal framework and pores. The metal framework is obtained by depositing metal on the surface of an organic polymer porous material and then removing the organic polymer porous material. The metal framework is a mixture of an open framework and a hollow framework. The open framework includes the space left after the metal deposition layer and the organic polymer porous material are removed. The space left is not completely surrounded by the metal deposition layer and can be directly connected to the external space. The hollow framework includes the space left after the metal deposition layer and the organic polymer porous material are removed. The space left is completely surrounded by the metal deposition layer and cannot be directly connected to the external space.

2. The electrode sheet according to claim 1, characterized in that, The active material is either a positive electrode active material or a negative electrode active material.

3. The electrode sheet according to claim 1, characterized in that, The open frame accounts for 20% to 100% of the total metal frame.

4. The electrode sheet according to claim 1, characterized in that, The open frame accounts for 80%-100% of the total metal frame.

5. The electrode sheet according to claim 1, characterized in that, The average pore diameter of the pores is 0.05–5 mm.

6. The electrode sheet according to claim 1, characterized in that, The thickness of the metal layer in the metal skeleton is 1 to 1000 μm.

7. The electrode sheet according to claim 1, characterized in that, The thickness of the porous metal is 0.005 to 65 mm.

8. The electrode sheet according to claim 1, characterized in that, The metal deposition layer is either a dual-mode metal deposition layer composed of two different sizes of grains or a multi-mode metal deposition layer composed of multiple different sizes of grains.

9. The electrode sheet according to claim 1, characterized in that, The metal deposition layer is a single metal material formed from any one of iron, nickel, copper, iron, aluminum, chromium, cadmium, germanium, tin, lead, zinc, gold, silver, titanium, cobalt, vanadium, niobium, hafnium, tantalum, bismuth, molybdenum, tungsten, manganese, platinum, palladium, ruthenium, rhodium, iridium, and osmium, or a multilayer metal material or alloy material formed from two or more of the above metals.

10. The electrode sheet according to claim 1, characterized in that, The porous metal is a three-dimensional porous metal.

11. The electrode sheet according to claim 1, characterized in that, The porous metal is a two-dimensional porous metal.

12. A secondary battery, comprising an anode plate, a cathode plate, a separator spaced between the anode plate and the cathode plate, and an electrolyte, characterized in that, The anode plate and / or the cathode plate use electrode plates according to any one of claims 1-11.

13. The secondary battery according to claim 12, characterized in that, The secondary battery is a lithium-ion secondary battery, a sodium-ion secondary battery, a zinc-ion secondary battery, a nickel-ion secondary battery, or a nickel-zinc battery.

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