Electrode preparation method, electrode prepared thereby, energy storage device comprising the electrode and electrode production system

Abstract

The present invention relates to an electrode preparation method, an electrode prepared thereby, an energy storage device comprising the electrode and an electrode production system for implementing the method. The preparation method comprises: (a) providing a free-standing electrode film, which comprises a first side and a second side opposite to the first side, wherein the second side comprises a region to be deposited, on which a metal is deposited when in contact with an electrolyte solution for an electrodeposition reaction; (b) providing an electrolyte solution containing a salt of a metal to be deposited; and (c) bringing at least the region to be deposited on the second side of the free-standing electrode film into contact with the electrolyte solution, and performing an electrodeposition reaction in the region to be deposited, thereby depositing, on the second side, a current collector of the metal to be deposited, wherein the electrodeposition temperature is 0°C to 70°C. The electrode prepared by the method of the present invention enables an active material therein to possess a good initial discharge specific capacity, initial Coulombic efficiency and cycling performance.

Description

Electrode fabrication method, electrode obtained therefrom, energy storage device including the electrode, and electrode production system.

[0001] This application claims priority to Chinese Patent Application No. 202510015650.1, filed on January 6, 2025, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] This invention generally relates to the field of electrochemical energy storage technology. Specifically, this invention relates to an electrode preparation method, an electrode obtained therefrom, an energy storage device including said electrode, and an electrode production system for performing said electrode preparation method. Background Technology

[0003] Electrochemical energy storage devices have wide applications in consumer electronics, electric vehicles, and energy storage grids. Electrodes, providing the site for charge storage / release, are crucial components of electrochemical devices. Traditional electrode fabrication methods involve coating or spraying electrode slurry onto a current collector, or bonding a self-supporting electrode film to the current collector via hot pressing. As demands for the performance of electrochemical energy storage devices, such as initial discharge specific capacity, initial coulombic efficiency, and cycle performance, increase, new electrode fabrication methods are needed to better meet these growing requirements. Therefore, it remains necessary to develop a new electrode fabrication method that enables energy storage devices assembled from electrodes prepared using this method to exhibit excellent initial discharge specific capacity, initial coulombic efficiency, and cycle performance. Summary of the Invention

[0004] This invention was made in view of the above-mentioned problems existing in the prior art.

[0005] In a first aspect, the present invention relates to a method for preparing an electrode, comprising:

[0006] (a) A self-supporting electrode film is provided, comprising a first side and a second side opposite to the first side, the second side comprising a region thereon on which metal is to be deposited when in contact with an electrolyte to perform an electrodeposition reaction;

[0007] (b) Provide an electrolyte containing a salt of the metal to be deposited;

[0008] (c) At least the region to be deposited on the second side of the self-supporting electrode film is brought into contact with the electrolyte, and an electrodeposition reaction is performed in the region to be deposited to deposit a current collector of the metal to be deposited on the second side, wherein the electrodeposition temperature is 0 to 70°C, preferably 0 to 30°C, more preferably 0 to 20°C, and even more preferably 0 to 10°C.

[0009] The preparation method of the present invention, by electrodepositing a current collector on a self-supporting electrode film, can significantly reduce the volume and mass proportion of auxiliary components (such as sheet-like current collectors used to coat active materials) in the battery, thereby improving the mass specific capacity and volumetric specific capacity of the energy storage device. Furthermore, in addition to the increase in specific capacity due to the reduction in the mass and volume of auxiliary components, unexpectedly, compared to electrodes prepared by coating positive and negative electrode active materials onto the positive and negative electrode current collectors, the electrode prepared by the method of the present invention exhibits higher initial discharge specific capacity, higher initial coulombic efficiency, and superior cycle performance.

[0010] The inventors unexpectedly discovered that controlling the electrodeposition temperature (i.e., electrolyte temperature) within a specific range, particularly within a relatively low temperature range, when preparing electrodes by electrodeposition on an electrode film can improve the initial discharge specific capacity, initial coulombic efficiency, and cycle performance of the active material contained in the electrode.

[0011] In addition, the inventors unexpectedly discovered that during electrodeposition, by providing an auxiliary conductor in contact with the self-supporting electrode film on part or all of the corresponding region on the first side of the self-supporting electrode film that is opposite to the region to be deposited on the second side, it is possible not only to significantly improve the electrodeposition efficiency and the uniformity of the deposited current collector layer, but also to significantly improve the first discharge specific capacity and cycle performance of the electrode thus produced.

[0012] In addition, the inventors have discovered that by adjusting the surface roughness of the self-supporting electrode film, the initial discharge specific capacity, initial coulombic efficiency, and cycle performance of the active material contained therein can be further improved.

[0013] In a second aspect, the present invention relates to electrodes obtained by the method described in the first aspect of the present invention.

[0014] In a third aspect, the present invention relates to an energy storage device comprising the electrodes described in the second aspect of the invention.

[0015] In a fourth aspect, the present invention relates to an electrode manufacturing system, comprising:

[0016] A self-supporting electrode film providing module is used to provide a self-supporting electrode film, the self-supporting electrode film including a first side and a second side opposite to the first side, the second side including a region to be deposited thereon on which metal is deposited when in contact with an electrolyte to perform an electrodeposition reaction;

[0017] An optional surface cleaning and treatment module, located upstream of the electrodeposition module, is used to clean and treat the surface of the self-supporting electrode film.

[0018] An electrolyte supply module is used to supply an electrolyte for electrodeposition to the electrodeposition module;

[0019] A temperature control module is used to control the temperature of the electrodeposition module to control the electrodeposition temperature to 0 to 70°C, preferably 0 to 30°C, more preferably 0 to 20°C, and even more preferably 0 to 10°C;

[0020] An electrodeposition module, located downstream of the self-supporting electrode film supply module and the electrolyte supply module, is used to deposit a current collector on the second side of the self-supporting electrode film.

[0021] An optional cleaning and drying module, located downstream of the electrodeposition module, is used to clean and dry the prepared electrodes.

[0022] A drive module is used to move the self-supporting electrode film between various modules of the electrode production system; and

[0023] An optional collection and delivery module is used to collect and deliver the prepared electrodes.

[0024] The electrode production system of the present invention has the advantages of simple process, high production efficiency, low energy consumption, no pollution, and can be easily combined with commonly used production equipment in the prior art, which is conducive to realizing continuous and large-scale production. Attached Figure Description

[0025] To more clearly illustrate the technical solution of the present invention, the accompanying drawings required for describing the embodiments will be briefly described below. It should be understood that these drawings are only for the purpose of facilitating a better understanding of the present invention by those skilled in the art, and are not intended to limit the scope of the present invention.

[0026] Figure 1 is a schematic diagram of the electrode preparation method of the present invention.

[0027] Figure 2 is a schematic diagram of setting an auxiliary conductor and a protective layer on a self-supporting electrode film.

[0028] Figure 3 shows the constant current first charge-discharge curves of button half-cell 1 and button half-cell 2 prepared according to Example 1.

[0029] Figures 4a and 4b show images of negative electrode 1 (Figure 4b) and negative electrode 2 (Figure 4a) after 100 charge-discharge cycles, respectively.

[0030] Figure 5 shows the areal density (mg / cm³) during the preparation of anode 3. 2 The variation of thickness with electrodeposition time.

[0031] Figure 6 shows the change in electrodeposition coverage effect with electrodeposition time during the preparation of anode 3 (Figure 6a: 60 seconds, Figure 6b: 120 seconds).

[0032] Figures 7a and 7b show cross-sectional scanning electron microscope images of negative electrode 2 (Figure 7b) and negative electrode 6 (Figure 7a), respectively.

[0033] Figure 8 shows a schematic diagram of testing the internal resistance of the electrode using the two-probe method.

[0034] Figure 9 shows the impedance test results for button half-cell 1 and button half-cell 2.

[0035] Figure 10 shows the changes in discharge specific capacity and energy density of full cell 1 and full cell 2 with the number of cycles.

[0036] Figure 11 shows images of negative electrodes prepared at different electrodeposition temperatures, from left to right: negative electrode 9, negative electrode 10, negative electrode 11, and negative electrode 12.

[0037] Figure 12 is a schematic diagram of one embodiment of the electrode production system of the present invention.

[0038] Figure 13 is a schematic diagram of another embodiment of the electrode production system of the present invention. Detailed Implementation

[0039] To make the inventive objectives, technical solutions, and beneficial technical effects of this application clearer, this application will be described in detail below. It should be noted that the various aspects, features, embodiments, and advantages described in this application can be compatible and / or combined together.

[0040] Unless otherwise specified, the technical terms used in this specification have the same meaning as commonly understood by those skilled in the art.

[0041] Unless otherwise specified in this application, the temperature is room temperature (25°C), the atmosphere is air, and the pressure is atmospheric pressure.

[0042] In the description of this invention, it should be understood that the terms "upper," "lower," "middle," etc., indicating orientation or positional relationship are only for the convenience of describing this invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0043] Furthermore, the terms “first,” “second,” etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0044] The present invention relates to an electrode preparation method, an electrode obtained therefrom, an energy storage device including the electrode, and an electrode production system for performing the electrode preparation method.

[0045] The electrode may be an electrode in an energy storage device, such as a secondary battery like a lithium-ion secondary battery or a sodium-ion secondary battery, or an electrode in a capacitor such as a supercapacitor, such as a positive electrode and / or a negative electrode.

[0046] The present invention will be described in detail below.

[0047] Electrode preparation method

[0048] In a first aspect, the present invention relates to a method for preparing an electrode, comprising:

[0049] (a) A self-supporting electrode film is provided, comprising a first side and a second side opposite to the first side, the second side comprising a region thereon on which metal is to be deposited when in contact with an electrolyte to perform an electrodeposition reaction;

[0050] (b) Provide an electrolyte containing a salt of the metal to be deposited;

[0051] (c) At least the region to be deposited on the second side of the self-supporting electrode film is brought into contact with the electrolyte, and an electrodeposition reaction is performed in the region to be deposited to deposit a current collector of the metal to be deposited on the second side, wherein the electrodeposition temperature is 0 to 70°C, preferably 0 to 30°C, more preferably 0 to 20°C, and even more preferably 0 to 10°C.

[0052] The preparation method of the present invention, by electrodepositing a current collector on a self-supporting electrode film, can significantly reduce the volume and mass proportion of auxiliary components (such as sheet-like current collectors used to coat active materials) in the battery, thereby improving the mass specific capacity and volumetric specific capacity of the energy storage device. Furthermore, in addition to the increase in specific capacity due to the reduction in the mass and volume of auxiliary components, unexpectedly, compared to electrodes prepared by coating positive and negative electrode active materials onto the positive and negative electrode current collectors, the electrode prepared by the method of the present invention exhibits higher initial discharge specific capacity, higher initial coulombic efficiency, and superior cycle performance.

[0053] The inventors unexpectedly discovered that controlling the electrodeposition temperature (i.e., electrolyte temperature) within a specific range, particularly within a relatively low temperature range, when preparing electrodes by electrodeposition on an electrode film can improve the initial discharge specific capacity, initial coulombic efficiency, and cycle performance of the active material contained in the electrode.

[0054] In addition, the inventors unexpectedly discovered that during electrodeposition, by providing an auxiliary conductor in contact with the self-supporting electrode film on part or all of the corresponding region on the first side of the self-supporting electrode film that is opposite to the region to be deposited on the second side, it is possible not only to significantly improve the electrodeposition efficiency and the uniformity of the deposited current collector layer, but also to significantly improve the first discharge specific capacity and cycle performance of the electrode thus produced.

[0055] In addition, the inventors have discovered that by adjusting the surface roughness of the self-supporting electrode film, the initial discharge specific capacity, initial coulombic efficiency, and cycle performance of the active material contained therein can be further improved.

[0056] Figure 1 is a schematic diagram of the electrode fabrication method of the present invention. Referring to Figure 1, the electrode fabrication method of the present invention may include: providing a self-supporting electrode film; providing an electrolyte containing a salt of the metal to be deposited; and electrodepositing a current collector on one side of the self-supporting electrode film.

[0057] The steps of the electrode preparation method of the present invention will be described in detail below.

[0058] Step (a)

[0059] Step (a) provides a self-supporting electrode film comprising a first side and a second side opposite to the first side, the second side comprising a region thereon on which metal is to be deposited when in contact with an electrolyte for an electrodeposition reaction.

[0060] As will be readily understood by those skilled in the art, the term "self-supporting" means that the electrode film can be self-supporting and has sufficient strength to be rolled up, handled, and unrolled during electrode manufacturing without other supporting elements.

[0061] The present invention does not have any special requirements for the self-supporting electrode film used, and can use self-supporting electrode films that are conventionally used in the art.

[0062] In some embodiments, the self-supporting electrode film may be commercially available. In some embodiments, the self-supporting electrode film may be prepared by conventional methods in the art. As an example, the self-supporting electrode film may be obtained by uniformly dispersing electrode active materials, conductive agents, binders, and optionally thickeners in a certain proportion, followed by processes such as rolling and drying.

[0063] The present invention does not impose any particular requirement on the amount of electrode active material in the self-supporting electrode film, and amounts commonly used in the art can be employed. As an example, based on the total dry weight of the self-supporting electrode film, the amount of the electrode active material can be 70-99% by weight, for example, 80-90% by weight.

[0064] This invention does not impose any particular requirements on the type and amount of conductive agent in the self-supporting electrode film; types and amounts commonly used in the art can be employed. As an example, the conductive agent may be selected from one or more of graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. Furthermore, as an example, based on the total dry weight of the self-supporting electrode film, the amount of the conductive agent may be 0.5-15.0% by weight, for example, 2.0-5.0% by weight.

[0065] This invention does not impose any particular requirements on the type and amount of binder in the self-supporting electrode film; types and amounts commonly used in the art can be employed. As an example, the binder may be selected from one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB), styrene-butadiene rubber (SBR), sodium carboxymethyl cellulose (CMC-Na), polyacrylic acid, polyvinyl alcohol, sodium alginate, poly(ethylene oxide), polyacrylonitrile, polyimide, cellulose, and cellulose derivatives (e.g., cellulose acetate, methylcellulose, ethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, nitrocellulose, carboxymethylcellulose, carboxyethylcellulose, carboxypropylcellulose, carboxyisopropylcellulose). Furthermore, as an example, based on the total dry weight of the self-supporting electrode film, the amount of the binder may be 0.5-15.0% by weight, for example, 2.0-5.0% by weight.

[0066] This invention does not impose any particular requirements on the type and amount of thickener in the self-supporting electrode film; types and amounts commonly used in the art can be employed. As an example, the thickener may be selected from sodium carboxymethyl cellulose, etc. As an example, based on the total dry weight of the self-supporting electrode film, the amount of the thickener may be 0.2-4.0% by weight, for example, 0.2-2.5% by weight.

[0067] Preferably, the surface roughness of at least one surface, and preferably both surfaces, of the self-supporting electrode film is 0.02-0.50 μm, for example, 0.02-0.20 μm. As used herein, the term "surface roughness" refers to the unevenness of a processed surface, characterized by small spacing and minute peaks and valleys, specifically the distance between two adjacent peaks or valleys. In some embodiments, the surface roughness of the surface on which electrodeposition is performed on the self-supporting electrode film is 0.02-0.50 μm, for example, 0.02-0.20 μm. In other embodiments, the surface roughness of both surfaces of the self-supporting electrode film is 0.02-0.50 μm, for example, 0.02-0.20 μm. As an example, the surface roughness may be 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, The surface roughness of the self-supporting electrode film is within the range defined by 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50 μm, or any two of these ranges. When the surface roughness of the self-supporting electrode film is within the above range, it helps to further improve the initial discharge specific capacity and cycle performance of the energy storage device assembled with electrodes prepared by the method of the present invention. The surface roughness of the self-supporting electrode film can be adjusted by methods commonly used in the art, such as by changing rolling conditions, plasma bombardment, surface etching, etc. The surface roughness can be measured by methods commonly used in the art, such as by interferometry, optical sectioning, etc.

[0068] In some embodiments, the thickness of the self-supporting electrode film of the present invention can be 10-500 μm, for example 20-200 μm. As an example, the thickness of the self-supporting electrode film can be within the range defined by 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 150, 180, 200, 220, 250, 280, 300, 320, 350, 380, 400, 420, 450, 480, 500 μm, or any two of these.

[0069] In some embodiments, the self-supporting electrode film is a positive electrode film, and the metal to be deposited is aluminum.

[0070] In some embodiments, the self-supporting electrode film is a negative electrode film, and the metal to be deposited is copper.

[0071] In some embodiments, the provided self-supporting electrode film may optionally be surface-cleaned before electrodeposition. For example, the first or second side, or both, of the self-supporting electrode film may be washed with solvents such as deionized water, ethanol, N-methylpyrrolidone, or other organic or inorganic solvents to remove impurities and contaminants from the surface of the self-supporting electrode film, ensuring a clean surface. Alternatively, the first or second side, or both, of the self-supporting electrode film may be purged with an airflow to remove particulate matter or residual solvent from the surface of the self-supporting electrode film. Preferably, the first or second side, or both, of the self-supporting electrode film may be washed with a solvent followed by airflow purging.

[0072] In some embodiments, the provided self-supporting electrode film may optionally undergo surface treatment. For example, rollers may be used to roll the self-supporting electrode film to apply normal and shear stresses to its surface, thereby reducing the porosity of the self-supporting electrode film and improving the surface smoothness of the electrode; and / or electrostatic corona treatment may be used to bring the self-supporting electrode film into a charged state to enhance the adhesion between the self-supporting electrode film and the deposited metal layer during electrodeposition; and / or plasma of gases such as argon or oxygen may be used to treat the surface of the self-supporting electrode film under normal pressure or vacuum conditions to generate physical and chemical reactions on the surface of the self-supporting electrode film, thereby improving the wettability of the surface of the self-supporting electrode film with the electrolyte and increasing the adhesion.

[0073] In some embodiments, step (a) further includes providing an auxiliary conductor on at least a portion or all of a first region on a first side of the self-supporting electrode film, the first region being a corresponding region opposite to the region to be deposited on the second side, the auxiliary conductor contacting the first region during electrodeposition.

[0074] This invention does not have special requirements for the material of the auxiliary conductor; any material with conductive properties commonly used by those skilled in the art can be used. In the example described, the material of the auxiliary conductor can be selected from one or more of the following: copper, aluminum, nickel, iron, gold, silver, platinum, tantalum, etc.

[0075] It should be noted that the term "part" means that the auxiliary conductor can form point contact, line contact, or surface contact with the first region. In the case of point contact, the auxiliary conductor contacts the first region only at a specific point; in other cases, the auxiliary conductor forms line contact or surface contact with the first region.

[0076] The phrase "corresponding region opposite to the deposition area on the second side" refers to a region on the self-supporting electrode film that is opposite to the deposition area along the normal direction (thickness direction of the self-supporting electrode film) of the deposition area on the second side. This can be understood with reference to Figure 2. Figure 2 is a schematic diagram of an auxiliary conductor and a protective layer disposed on a self-supporting electrode film. In Figure 2, the auxiliary conductor 12 is disposed on the self-supporting electrode film 13, the protective layer 11 is disposed on the auxiliary conductor 12, 15 is the deposition area on the second side of the self-supporting electrode film 13, and 14 is the corresponding region of the self-supporting electrode film 13 opposite to the deposition area 15 on the second side, i.e., the first region. In Figure 2, the auxiliary conductor exemplary completely covers the first region.

[0077] In some embodiments, the auxiliary conductor is selected from metal foil, such as copper foil or aluminum foil, and step (a) optionally includes providing a protective layer on at least the first region on the first side of the self-supporting electrode film, the protective layer being used to protect the first side from the deposition of current collectors during electrodeposition. The method further includes removing the auxiliary conductor and the optional protective layer after electrodeposition is completed. As an example, the protective layer may completely cover the first side, or, if the self-supporting electrode film is only partially immersed in the electrolyte, it may completely cover the first region but not necessarily the first side of the self-supporting electrode film. As an example, the auxiliary conductor may be disposed between the first side of the self-supporting electrode film and the protective layer.

[0078] The present invention does not have special requirements for the material of the protective layer, and materials commonly used by those skilled in the art can be used, as long as they can effectively protect the first side of the self-supporting electrode film from the deposition of current collectors during the electrodeposition process. As an example, the protective layer may be made of one or more materials selected from polyimide (PI), polyethylene (PE), polypropylene (PP), and polytetrafluoroethylene (PTFE).

[0079] In some embodiments, the auxiliary conductor is selected from a conductive roller, all or at least its surface of which is made of metal such as copper or aluminum. Those skilled in the art will readily understand that, when the auxiliary conductor is a conductive roller, for example in a continuous production process, the electrode formed by electrodeposition can separate from the auxiliary conductive roller as the auxiliary conductive roller rotates and as the electrode itself moves.

[0080] Step (b)

[0081] Step (b) provides an electrolyte containing a salt of the metal to be deposited.

[0082] The present invention does not have any particular requirements for the composition of the electrolyte. Electrolytes commonly used in the art for electrodeposition can be used, as long as the electrolyte contains a salt of the metal to be deposited so as to effectively deposit the metal.

[0083] In some embodiments, the metal to be deposited may be a metallic element commonly used in current collectors in the art. As an example, the metal to be deposited may be one or more selected from copper, aluminum, nickel, iron, gold, silver, platinum, tantalum, etc.

[0084] Those skilled in the art will readily understand that the electrolyte can be an aqueous or non-aqueous system, and includes: a solvent; a salt containing the metal to be deposited; and optionally one or more of a leveling agent, brightener, stabilizer, acid, or alkali. The present invention does not have particular requirements regarding the type of salt containing the metal to be deposited, as long as it can effectively deposit the metal during electrodeposition. As an example, the salt containing the metal to be deposited can be selected from one or more of sulfates of the metal to be deposited, such as copper sulfate, zinc sulfate, nickel sulfate, and chlorides such as nickel chloride.

[0085] This invention does not impose any particular requirements on the concentration of the salt containing the metal to be deposited, and concentration ranges commonly used in the art can be used. As an example, the concentration of the salt containing the metal to be deposited can be 50-500 g / L, for example 50-350 g / L.

[0086] In some embodiments, the electrolyte is an aqueous system, and the solvent includes water and optionally further includes an organic solvent miscible with water. For example, the electrolyte may be a mixed aqueous solution of copper sulfate, glucose, and sulfuric acid.

[0087] In some embodiments, the electrolyte is a non-aqueous system, and the electrolyte includes organic solvents and / or ionic liquids.

[0088] Preferably, the organic solvent may be selected from one or more of ethers (e.g., tetrahydrofuran), aromatic hydrocarbons, and their derivatives. For example, the organic solvent may be dimethyl sulfoxide. For example, the electrolyte may be AlBr3-MBr-benzene (where M is a metal), such as AlCl3-toluene-ethylbenzene.

[0089] Preferably, the ionic liquid is selected from one or more of haloalkylpyridines, haloalkylimidazolines, or haloalkylarylammonium salts. For example, the ionic liquid may be selected from 1-ethyl-3-methylimidazolium chloride [EMIMCl].

[0090] This invention does not impose any particular requirements on the leveling agents, brighteners, stabilizers, acids, or bases contained in the electrolyte; leveling agents, brighteners, stabilizers, acids, or bases commonly used in the art can be used. As examples, leveling agents can be selected from one or more of the following: metals such as cobalt, manganese, and nickel; sugars such as glucose; and sulfur- or phosphorus-containing organic compounds. Brighteners can be selected from one or more of the following: aldehydes, ketones, organic compounds containing double or triple bonds, heterocyclic compounds, or metals, such as ethylene thiourea, dithiobenzoimazole, tetrahydrothiazolylthione, benzyl propionyl copper, o-chlorobenzaldehyde, carmine aldehyde, phenylene alcohol (BPC), etherified products of butynediol and propynediol, and saccharin (o-sulfonylbenzylimide). Stabilizers can be selected from compounds of S, Se, and Te, for example, oxygen-containing compounds, and heavy metal ions such as Pb. 2+ Sn 2+ Sb 3+ Cd 2+ The following are water-soluble organic compounds, such as alcohols, ketones, amines, etc.; the acid may be selected from sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, chromic acid, etc.; and the base may be selected from sodium hydroxide, soda ash, sodium silicate, sodium tripolyphosphate, etc.

[0091] This invention does not impose any particular requirements on the concentrations of the smoothing agent, brightening agent, stabilizer, acid, or alkali contained in the electrolyte; concentration ranges commonly used in the art can be used. For example, the concentrations of the smoothing agent, brightening agent, stabilizer, acid, or alkali can each be 1-100 g / L.

[0092] Step (c)

[0093] Step (c) involves contacting at least the region to be deposited on the second side of the self-supporting electrode film with the electrolyte and performing an electrodeposition reaction in the region to be deposited to deposit a current collector of the metal to be deposited on the second side, wherein the electrodeposition temperature is 0 to 70°C, preferably 0 to 30°C, more preferably 0 to 20°C, and even more preferably 0 to 10°C.

[0094] The inventors unexpectedly discovered that controlling the electrodeposition temperature (i.e., electrolyte temperature) within a specific range, particularly within a relatively low temperature range, during electrode fabrication by electrodeposition on an electrode film can improve the initial discharge specific capacity, initial coulombic efficiency, and cycle performance of the active material contained in the electrode. Further improvements in initial discharge specific capacity, initial coulombic efficiency, and cycle performance can be achieved when the electrodeposition temperature is in the range of 0 to 20°C, preferably 0 to 10°C.

[0095] In embodiments, the electrodeposition temperature can be from 0 to 70°C, preferably from 0 to 30°C, more preferably from 0 to 20°C, and even more preferably from 0 to 10°C, for example, it can be within the range defined by 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 35, 38, 40, 42, 45, 48, 50, 52, 55, 58, 60, 62, 65, 68, 70°C, or any two of them.

[0096] Those skilled in the art will readily understand that the electrodeposition process can be carried out using methods commonly used in the art. For example, a self-supporting electrode film can be used as the cathode, and a current collector metal as the anode, or a metal sheet or foil containing a current collector metal can be used as the anode, with the cathode and anode placed in an electrolyte. A circuit is then formed with an external power supply, wherein the cathode is connected to the negative terminal of the power supply and the anode is connected to the positive terminal. Under the influence of current, the anode dissolves and the corresponding metal is deposited on the cathode surface.

[0097] This invention does not impose any special requirements on other process conditions of the electrodeposition process, and process conditions commonly used by those skilled in the art can be used.

[0098] In some implementations, the current used in the electrodeposition process can be selected from any of the following: DC constant current, pulse, square wave, triangular wave, sine wave, or superposition of the above.

[0099] In some implementations, the current density used during electrodeposition can be 0.1-10 A / dm³. 2 For example, 0.5-8A / dm 2 .

[0100] In some embodiments, the electrodeposition time used in the electrodeposition process can be 30-1800 seconds, for example 50-1500 seconds. As an example, the electrodeposition time can be within the range defined by 30, 50, 80, 100, 120, 150, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1200, 1500, 1600, 1800 seconds, or any two of them.

[0101] In some embodiments, the thickness of the current collector formed by electrodeposition can be 0.1-20.0 μm, for example 0.5-15.0 μm. As an example, the thickness of the current collector formed by electrodeposition can be within the range defined by 0.1, 0.2, 0.3, 0.4, 0.5, 0.8, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5, 20.0 μm, or any two of these.

[0102] In some embodiments, the electrodeposition process can be carried out in an air atmosphere, or in a vacuum, or in an atmosphere selected from one or more of argon, nitrogen, or mixtures thereof. For economic reasons, the electrodeposition process is preferably carried out in an air atmosphere.

[0103] Those skilled in the art will readily understand that, after the electrodeposition process is complete, the resulting electrode can be separated from the optional auxiliary conductor and optional protective layer.

[0104] In some embodiments, the prepared electrode may also be cleaned and dried. For example, the prepared electrode may be thoroughly cleaned in water or an organic solvent, for example, 1 to 5 times. Optionally, the cleaned electrode may be purged with a gas stream and / or heated under air, argon, nitrogen, or vacuum conditions to evaporate any residual solvent on the surface, thereby obtaining a dried electrode.

[0105] electrode

[0106] A second aspect of the present invention provides an electrode prepared by the electrode preparation method according to the first aspect of the present invention.

[0107] Energy storage devices

[0108] A third aspect of the present invention provides an energy storage device comprising the electrodes described in the second aspect of the present invention.

[0109] The electrode may be the positive electrode and / or negative electrode of the energy storage device.

[0110] In some embodiments, the energy storage device may be a lithium-ion secondary battery. For lithium-ion secondary batteries, when depositing a positive electrode current collector, the positive electrode active material in the self-supporting electrode film may be selected from one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium phosphates with an olivine structure, preferably LiMn2O4, LiNiMnCoO2, or LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.5 Co 0.3 Mn 0.2 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 One or more of O2 and LiFePO4; in the case of depositing the negative electrode current collector, the negative electrode active material in the self-supporting electrode film may be selected from one or more of natural graphite, artificial graphite, mesophase micro carbon spheres (MCMB), hard carbon, soft carbon, silicon-based materials, tin-based materials, lithium titanate and lithium metal, preferably one or more of graphite and silicon-based materials, more preferably one or more of graphite, silicon-carbon composite and silicon alloy.

[0111] In some embodiments, the energy storage device may be a sodium-ion secondary battery. For sodium-ion secondary batteries, when depositing the positive electrode current collector, the positive electrode active material may be selected from one or more of layered transition metal oxides or Prussian blue analogues, preferably NaNi. 1 / 3 Fe 1 / 3 Mn 1 / 3 O2, Na2FeP2O7, Na4Fe3(PO4)2(P2O7), Na3V2(PO4)3, NaFePO4, and NaMnFe(CN)6 are selected as one or more. In the case of depositing the negative electrode current collector, the negative electrode active material can be selected from one or more of natural graphite, artificial graphite, mesophase micro carbon spheres (MCMB), hard carbon, soft carbon, silicon-based materials, and tin-based materials, preferably one or more of graphite and silicon-based materials, and more preferably one or more of graphite, silicon-carbon composites, and silicon alloys.

[0112] In some embodiments, the energy storage device may be a supercapacitor. For a supercapacitor, when depositing a positive current collector, the positive active material may be selected from one or more of metal oxides, conductive polymers, and carbon materials, preferably one or more of MnO2, NiO, Co3O4, polyaniline, polypyrrole, activated carbon, graphene, and biochar; when depositing a negative current collector, the negative active material may be selected from one or more of metals, carbon materials, conductive polymers, metal oxides, and metal-organic framework (MOF) derived materials, preferably one or more of aluminum, zinc, activated carbon, graphite, polyaniline, polypyrrole, polythiophene, and MnO2.

[0113] Electrode production system

[0114] A fourth aspect of the present invention provides an electrode production system for performing the method according to the first aspect of the present invention, comprising:

[0115] A self-supporting electrode film providing module is used to provide a self-supporting electrode film, the self-supporting electrode film including a first side and a second side opposite to the first side, the second side including a region to be deposited thereon on which metal is deposited when in contact with an electrolyte to perform an electrodeposition reaction;

[0116] An optional surface cleaning and treatment module, located upstream of the electrodeposition module, is used to clean and treat the surface of the self-supporting electrode film.

[0117] An electrolyte supply module is used to supply an electrolyte for electrodeposition to the electrodeposition module;

[0118] A temperature control module is used to control the temperature of the electrodeposition module to control the electrodeposition temperature to 0 to 70°C, preferably 0 to 30°C, more preferably 0 to 20°C, and even more preferably 0 to 10°C;

[0119] An electrodeposition module, located downstream of the self-supporting electrode film supply module and the electrolyte supply module, is used to deposit a current collector on the second side of the self-supporting electrode film.

[0120] An optional cleaning and drying module, located downstream of the electrodeposition module, is used to clean and dry the prepared electrodes.

[0121] A drive module is used to move the self-supporting electrode film between various modules of the electrode production system; and

[0122] An optional collection and delivery module is used to collect and deliver the prepared electrodes.

[0123] The electrode production system of the present invention has the advantages of simple process, high production efficiency, low energy consumption, no pollution, and can be easily combined with commonly used production equipment in the prior art, which is conducive to realizing continuous and large-scale production.

[0124] Figure 12 is a schematic diagram of one embodiment of the electrode production system of the present invention. Referring to Figure 12, the electrode production system of the present invention includes a self-supporting electrode film providing module (120, which provides a self-supporting electrode film 120'), an electrolyte providing module (not shown), a temperature control module (not shown), a transmission module, and an electrodeposition region 100 (which includes a cathode 120' (self-supporting electrode film) and an anode 110).

[0125] In a typical implementation, a self-supporting electrode film provided by a self-supporting electrode film supply module is transported to an electrodeposition module via a transmission module, where it comes into contact with an electrolyte provided by an electrolyte supply module, and electrodeposition occurs. During electrodeposition, a temperature control module controls the electrodeposition temperature.

[0126] In some embodiments, the electrode production system of the present invention further includes an optional surface cleaning and treatment module located upstream of the electrodeposition module, for cleaning and treating the surface of the self-supporting electrode film. For details of the specific cleaning and treatment process, please refer to the description of step (a) above, which will not be repeated here.

[0127] In some embodiments, the electrode production system of the present invention further includes an optional cleaning and drying module 200, located downstream of the electrodeposition module, for cleaning and drying the produced electrode. For details of the specific cleaning and drying process, please refer to the description of step (a) above, which will not be repeated here.

[0128] In some embodiments, the electrode production system of the present invention further includes an optional collection and transport module for collecting and transporting the prepared electrodes.

[0129] In some embodiments, the electrode production system of the present invention further includes an optional auxiliary conductor placement module, located downstream of the self-supporting electrode film providing module and the optional surface cleaning and treatment module and upstream of the electrodeposition module, for placing an auxiliary conductor on at least a portion or all of a first region on a first side of the self-supporting electrode film, the first region being a corresponding region opposite to the region to be deposited on the second side, wherein the auxiliary conductor contacts the first region during electrodeposition. For a detailed description of the auxiliary conductor, please refer to the description of step (a) above, which will not be repeated here.

[0130] In some embodiments, the electrode production system of the present invention further includes:

[0131] An optional protective layer setting module 310, located downstream of the self-supporting electrode film providing module and the optional auxiliary conductor setting module and upstream of the electrodeposition module, is used to set a protective layer on at least the first region on the first side of the self-supporting electrode film, the protective layer being used to protect the first side from depositing current collectors during the electrodeposition process.

[0132] An optional separation module, located downstream of the electrodeposition module, is used to remove an optional auxiliary conductor and an optional protective layer;

[0133] An optional protective layer circulation module 320, located downstream of the optional separation module, is used to transfer the separated protective layer to the optional protective layer setting module 310 for reuse; and

[0134] An optional rolling module may include a first part and an optional second part, wherein the first part is located upstream of the self-supporting electrode film providing module for rolling the self-supporting electrode film, and the optional second part is located downstream of the optional separation module for rolling the resulting electrode.

[0135] In some embodiments, the starting end of the optional protective layer setting module 310 is connected to the end of the optional protective layer circulation module 320, thereby enabling the cyclic use of the protective layer.

[0136] Figure 13 illustrates another embodiment of the electrode production system of the present invention. Referring to Figure 13, the electrode production system further includes a rolling module comprising a first portion and an optional second portion, wherein the first portion is located upstream of the self-supporting electrode film providing module for rolling the self-supporting electrode film, and the optional second portion is located downstream of the optional separation module for rolling the produced electrode. In some embodiments, the rolling module may consist only of the first portion.

[0137] In some embodiments, the electrode production system of the present invention may further include other modules upstream of the self-supporting electrode film supply module for mixing, fibrillating, etc., the raw materials for the self-supporting electrode film.

[0138] In some embodiments, the electrode production system of the present invention is a continuous production system.

[0139] In some embodiments, the electrode production system of the present invention is an automated production system. Those skilled in the art will readily understand that an automatic sample feeding device for self-supporting electrode films, electrolytes, electrodeposition anodes, etc., can be used as needed to achieve automated production.

[0140] Example

[0141] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0142] Example 1: Current collector thickness and weight, and their respective proportions to the overall electrode thickness and weight.

[0143] A self-supporting graphite electrode film was prepared as follows: Graphite (S360-L2-H), conductive carbon black (TIMCAL Super P Li), polytetrafluoroethylene (MSK-F104), and polyvinylidene fluoride (HSV900) were ball-milled at 600 rpm for 60 min to disperse them evenly in a mass ratio of 85:5:5:5. Then, the film was subjected to a process at 180℃ and 200 kgf / cm². 2 Under these conditions, the film is extruded multiple times using rollers to achieve the target parameters (to a film thickness of 100 μm).

[0144] Negative electrode preparation: A mixed aqueous solution of 200 g / L copper sulfate pentahydrate, 20 g / L glucose, and 65 g / L sulfuric acid was prepared as the electrolyte for copper plating on the negative electrode surface. An insulating PE film was attached to one surface of the self-supporting graphite electrode film prepared as described above. Then, the graphite film with the insulating PE film attached and the copper foil were immersed together in the prepared electrolyte. The graphite film with the insulating PE film attached was used as the cathode, and the copper foil as the anode. Direct current was used as the power source, and 2.5 A / dm² was applied. 2 Electrodeposition was performed at a current density of 100 kJ / cm² at 0 °C for 100 seconds. Afterwards, the graphite film with the insulating PE film attached was removed, the insulating PE film was removed, and the film was dried to obtain a negative electrode 1 with an electrodeposited current current thickness of 1.2 μm. Correspondingly, the self-supporting graphite electrode film prepared as described above was subjected to an current density of 180 °C and 500 kgf / cm² for 100 seconds. 2 Under certain conditions, the negative electrode 2 was obtained by hot pressing and laminating with 9μm carbon-coated copper foil (8μm copper + 1μm carbon, purchased from Shenzhen Kejing Company (MTI)).

[0145] Preparation of half-cells: Negative electrodes 1 and 2 were cut into 14mm diameter discs and vacuum-dried at 80℃ for 12h, then transferred to an argon-filled glove box (water and oxygen content <0.5ppm). The negative electrodes, Celgard 2350 separator, lithium sheet, stainless steel gasket, and stainless steel spring were sequentially placed in a CR2032 button cell casing. Then, 25μL of electrolyte (a 1M LiPF6 solution in a mixed solvent: ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a 1:1 volume ratio, and 10% fluoroethylene carbonate (FEC) and 1% vinylene carbonate (VC) were added based on the total volume fraction of EC+DEC) to each side of the separator. After stacking, the cells were hydraulically sealed and allowed to stand for 12h to allow the electrolyte to fully impregnate the electrode pores, thus obtaining button half-cells 1 and 2.

[0146] Charge-discharge test: At 30°C, CR2032 button half-cells 1 and 2 were lithium-intercalated to 0.005V at a constant current of 0.2C, then allowed to stand for 5 minutes, and then delithiated to 2.0V at a constant current of 0.5C. This constitutes one charge-discharge cycle. The discharge capacity and charge capacity at the first charge-discharge cycle were recorded as the first discharge capacity and the first charge capacity. Similarly, the discharge capacity and charge capacity at the nth cycle were recorded as the discharge capacity and charge capacity of the nth cycle. The first coulombic efficiency was obtained by dividing the first discharge capacity by the first charge capacity and multiplying by 100%.

[0147] Table 1 lists the current collector thickness and weight of negative electrode 1 and negative electrode 2, as well as their respective proportions to the total negative electrode.

[0148] Table 1: Current collector thickness and weight of negative electrode 1 and negative electrode 2, and their respective proportions to the total thickness and weight of the negative electrode.

[0149] As can be seen from Table 1, compared with the current collectors prepared by traditional hot pressing lamination, the ultrathin current collectors prepared by electrodeposition can significantly reduce the thickness and weight of the current collector layer and their proportion of the overall thickness and weight of the electrode, thereby significantly increasing the proportion of active material in the electrode.

[0150] Figure 3 shows the constant current initial charge-discharge curves of button half-cell 1 and button half-cell 2. Referring to Figure 1, the initial coulombic efficiencies of button half-cell 1 and button half-cell 2 are 80.81% and 73.02%, respectively. This indicates that the electrode prepared by the method of the present invention possesses a higher initial coulombic efficiency.

[0151] Figures 4a and 4b show images of negative electrode 1 (Figure 4b) and negative electrode 2 (Figure 4a) after 100 charge-discharge cycles, respectively. As can be seen from Figures 4a and 4b, negative electrode 1 prepared by the method of the present invention remains intact after charge-discharge cycles, while negative electrode 2 prepared by conventional lamination shows separation of the current collector from the self-supporting electrode film after charge-discharge cycles.

[0152] Example 2: Electrodeposition Time

[0153] A mixed aqueous solution of 200 g / L copper sulfate pentahydrate, 20 g / L glucose, and 65 g / L sulfuric acid was prepared as the electrolyte for copper plating on the negative electrode surface. An insulating PE film was attached to one side of the self-supporting graphite electrode film prepared in Example 1. Then, the graphite electrode film and copper foil were immersed together in the electrolyte and connected to a power source to form a two-electrode system, wherein the graphite electrode film was used as the cathode and the copper foil as the anode. Direct current was used as the power source, and 2.5 A / dm² was applied. 2 Electrodeposition was performed at a current density of 100 ppm at 0°C for 100 seconds. Afterwards, the graphite film with the insulating PE film attached was removed, the PE film was removed, and the electrode was dried to obtain the negative electrode 3, which included the electrodeposited current collector. The amount of copper deposited on the graphite electrode surface and the relationship between the coverage effect and the deposition time were recorded.

[0154] Figure 5 shows the areal density (mg / cm³) during the preparation of anode 3. 2 The thickness and areal density of the electrodeposited current collector increase with electrodeposition time. As shown in Figure 5, the thickness and areal density of the electrodeposited current collector increase with increasing electrodeposition time; when the electrodeposition time reaches 600 seconds, it can basically achieve areal density and thickness close to those of commercial copper foil (purchased from Shenzhen MTI Co., Ltd., the same below).

[0155] Figures 6a and 6b show the variation of electrodeposition coverage during the preparation of negative electrode 3 with electrodeposition time (Figure 6a: 60 seconds, Figure 6b: 120 seconds). Figures 6a and 6b show that at 60 seconds of electrodeposition, the electrodeposited current collector has not completely covered the self-supporting graphite electrode film; at 120 seconds of electrodeposition, the electrodeposited current collector has completely covered the self-supporting graphite electrode film.

[0156] As can be seen from Figures 5 and 6a-6b, the method of the present invention can quickly achieve uniform coverage of ultrathin current collectors on the surface of the self-supporting electrode film, which is suitable for large-scale applications.

[0157] Example 3: Uniformity of electrodeposited current collector

[0158] A self-supporting graphite electrode film prepared in Example 1 was provided and cut into strips of 2 × 10 cm. A mixed aqueous solution of 200 g / L copper sulfate pentahydrate, 20 g / L glucose, and 65 g / L sulfuric acid was prepared as the electrolyte for copper plating on the negative electrode surface. The strips of the self-supporting graphite electrode film were divided into two groups, one strip per group. One group had an insulating PE film attached to one side, and the other group had an auxiliary conductive copper foil of equal area attached to one side, followed by a conformally attached insulating PE film. The two groups of strip-shaped electrode films were vertically submerged in the electrolyte solution to 4 / 5 of their area and connected to a power source to form a two-electrode system, wherein the self-supporting graphite electrode film served as the cathode, and the copper foil served as the anode. Direct current (DC) was used as the power source, with a current of 2.5 A / dm². 2 Electrodeposition was performed at a current density of 0°C for 600 seconds. After electrodeposition, the graphite film with the insulating PE film was removed, the insulating PE film was removed, and the graphite film was rinsed three times with deionized water and dried to obtain negative electrode 4. After electrodeposition, the graphite film with both auxiliary conductive copper foil and insulating PE film was removed, the graphite film with both auxiliary conductive copper foil and insulating PE film was removed, and the graphite film was rinsed three times with deionized water and dried to obtain negative electrode 5. The portions of negative electrodes 4 and 5 immersed in the electrolyte were divided into upper, middle, and lower sections, and the thickness of the copper current collector deposited in each section was recorded (average value of the sample).

[0159] Preparation of button half-cells: Negative electrodes 4 and 5 were assembled into button half-cells according to the method in Example 1. Then, 100 charge-discharge cycle tests were performed, except that the charge-discharge rate was 1C, and the rest was the same as in Example 1.

[0160] Discharge specific capacity: The discharge capacity of each cycle is used as the numerator, and the weight (dry weight) of the active material in the positive electrode active material layer of the battery is used as the denominator. The two are divided to obtain the discharge specific capacity.

[0161] Table 2 lists the thickness, average thickness, and variance of the upper, middle, and lower sections of negative electrode 4 and negative electrode 5.

[0162] Table 2: Thickness, average thickness, and variance of the upper, middle, and lower sections of negative electrode 4 and negative electrode 5.

[0163] As shown in Table 2, compared to the negative electrode 4 which only has an insulating PE film during electrodeposition, the negative electrode 5, which has both an insulating PE film and an auxiliary conductive copper foil during electrodeposition, has a larger thickness in its upper, middle, and lower sections, and a smaller thickness variance. This indicates that by placing an auxiliary conductor on the opposite side of the self-supporting electrode film during electrodeposition, it is helpful to improve the deposition rate and deposition uniformity.

[0164] Table 3 lists the electrochemical performance test results of the button half-cells assembled with negative electrode 4 and negative electrode 5, respectively.

[0165] Table 3: Electrochemical performance test results of the coin half-cell assembled with negative electrode 4 and negative electrode 5

[0166] The coin cell assembled with negative electrode 5 exhibits an initial discharge specific capacity of approximately 263.4 mAh / g, while the coin cell assembled with negative electrode 4 only exhibits an initial discharge specific capacity of approximately 249.7 mAh / g. This is unexpected, as negative electrodes 4 and 5 use the same negative electrode active material, and it is generally assumed that their discharge specific capacities should be the same. However, the results show that the coin cell assembled with the negative electrode prepared by the method of the present invention has a higher discharge specific capacity. This indicates that the electrode preparation method of the present invention is beneficial for improving the discharge specific capacity of the active material.

[0167] Furthermore, the button half-cell assembled from the negative electrode prepared by the method of the present invention also has a higher specific capacity retention rate, which indicates that the electrode preparation method of the present invention is beneficial to improving cycle performance.

[0168] Example 4: Interfacial bonding between self-supporting electrode film and current collector

[0169] We provide commercial current collectors (copper foil purchased from Shenzhen MTI Co., Ltd.).

[0170] A current collector of the same thickness as a commercial current collector was prepared by electrodeposition, specifically as follows: A self-supporting graphite electrode film prepared in Example 1 was provided, and an insulating PE film was laminated to one side of it. A mixed aqueous solution of copper sulfate pentahydrate (200 g / L), glucose (20 g / L), and sulfuric acid (65 g / L) was prepared as the electrolyte for copper plating on the surface of the graphite self-supporting electrode film. The graphite self-supporting electrode film with the insulating PE film laminated and the copper foil were immersed together in the electrolyte and connected to a power source to form a two-electrode system, wherein the graphite self-supporting electrode film with the insulating PE film laminated served as the cathode and the copper foil served as the anode. Direct current was used as the power source, and 2.5 A / dm² was used. 2 Electrodeposition was performed at a current density of 0°C for 720 seconds. The electrode was then washed three times with deionized water and dried to obtain the negative electrode 6.

[0171] The negative electrodes 2 and 6 were subjected to a 180° peel test using a universal testing machine (ZWICKZ020) as follows: The active material side of the composite electrode under test was fixed on a horizontally placed substrate, and test tape was attached to the current collector side. The tape and substrate were respectively fixed to the ZWICKZ020 universal testing machine with clamps at 180° angles at both ends. Tension was applied at a rate of 5 cm / min, i.e., current collector peeling was performed on the electrode surface, and the peel force and displacement information were recorded.

[0172] Figures 7a and 7b show cross-sectional scanning electron microscope (SEM) images of negative electrode 2 (Figure 7b) and negative electrode 6 (Figure 7a), respectively. Cross-sectional SEM tests were performed using a Zeiss Gemini microscope under the following conditions: magnification 3k and accelerating voltage 5kV.

[0173] As shown in Figure 7, the commercial current collectors obtained by traditional lamination still inevitably delaminate even under high temperature and high pressure lamination. In contrast, the current collectors obtained by electrodeposition have a tighter bond with the self-supporting electrode film. This is mechanically reflected in the fact that the peel strength of negative electrode 6 is significantly higher than that of negative electrode 2 (see Table 4).

[0174] Table 4: Comparison of bonding strength between commercial current collectors and electrodeposited current collectors

[0175] Example 5: Electrode Internal Resistance

[0176] The internal resistance of the negative electrode 1 and negative electrode 2 prepared in Example 1, as well as the self-supporting electrode film prepared in Example 1 alone (i.e. not combined with any current collector) was tested using a two-probe system (the principle is shown in Figure 8, Yuaneng BER2500).

[0177] Table 5: Comparison of Internal Resistance

[0178] Referring to Figure 8, the resistance value of the electrode tested by the two-probe method can be decomposed into the intrinsic resistance R of the self-supporting electrode film. 电极膜 The intrinsic resistance R of the foil (current collector) 箔材 Contact resistance R' between the self-supporting electrode film and the upper probe A 电极膜-A Contact resistance R' between the electrode film and the foil 电极膜-箔材 Contact resistance R' between the foil and the lower probe B 箔材-B The sum of R 总 .

[0179] Referring to Table 5, compared to a standalone self-supporting electrode film, the total internal resistance of the negative electrode 1 prepared by electrodeposition increases only slightly, while the internal resistance of the negative electrode 2 prepared by conventional lamination increases to approximately three times. This indicates that the electrodeposition method for preparing current collectors can simultaneously achieve less metal material consumption and lower electrode internal resistance, thereby improving the economy and energy efficiency of the battery.

[0180] Example 6: Electrode Impedance

[0181] The button half-cells 1 and 2 prepared in Example 1 were used for AC impedance testing. After the assembled button half-cells 1 and 2 were charged and discharged at a rate of 0.1C within a voltage range of 0.005 to 1.5V for 3 charge-discharge cycles, lithium was inserted to bring them to a state of charge (SOC) of 50% before impedance testing was performed.

[0182] Electrochemical impedance spectroscopy was performed using the Chenhua CHI660e electrochemical workstation under the following conditions: frequency range 100kHz to 0.01Hz, AC voltage amplitude 10mV.

[0183] Figure 9 shows the impedance test results for button half-cell 1 and button half-cell 2. Referring to Figure 9, the impedance of button half-cell 1 is approximately 15 Ω, while the impedance of button half-cell 2 is approximately 22 Ω. This indicates that the electrode prepared by electrodeposition of the current collector has better interfacial contact and therefore lower interfacial impedance.

[0184] Example 7: Lithium-ion Battery Application - Electrode Cycling

[0185] The negative electrode 1 and negative electrode 2 prepared in Example 1 will be used as the negative electrodes of the lithium-ion secondary battery.

[0186] Preparation of self-supporting lithium iron phosphate electrode film: Lithium iron phosphate (P198-S20), conductive carbon black (TIMCAL Super P Li), polytetrafluoroethylene, and polyvinylidene fluoride were ball-milled at 600 rpm for 60 min at a mass ratio of 85:5:5:5 to disperse the components evenly. Then, the film was subjected to a process at 180℃ and 200 kgf / cm². 2 Under these conditions, the film was extruded multiple times using rollers until the target parameters were reached (to a film thickness of 150 μm).

[0187] The positive electrode for a lithium-ion secondary battery was prepared as follows: In a glove box, aluminum chloride powder was added to 1-ethyl-3-methylimidazolium chloride [EMIMCl] at a molar ratio of aluminum chloride to ionic liquid of 1.3:1. After stirring and dissolving, an electrolyte for electrodeposition of aluminum was obtained. A self-supporting lithium iron phosphate electrode film prepared as described above was coated with an insulating PE film on one side and immersed in the electrolyte along with aluminum foil (purchased from Shenzhen MTI Co., Ltd., hereinafter the same). This was connected to a power source to form a two-electrode system, with the lithium iron phosphate film serving as the cathode and the aluminum foil as the anode. Direct current was used as the power source, and a voltage of 3.5 A / dm² was applied. 2 Electrodeposition was performed at a current density of 180 kJ / cm² at 25 °C for 180 seconds. Afterwards, the self-supporting lithium iron phosphate electrode film with the insulating PE film was removed, the PE film was removed, and after drying, a positive electrode 1 with an electrodeposited current current thickness of 2 μm was obtained. Correspondingly, the self-supporting lithium iron phosphate electrode film was subjected to current density of 180 °C and 500 kgf / cm² for 180 seconds. 2Under certain conditions, it was hot-pressed with 16μm carbon-coated aluminum foil (15μm aluminum + 1μm carbon) to obtain positive electrode 2.

[0188] Lithium-ion battery assembly: Negative electrodes 1 and 2 are cut into 14mm diameter discs, and positive electrodes 1 and 2 are cut into 13mm diameter discs. After vacuum drying at 80℃ for 12 hours, they are transferred to an argon-filled glove box (water and oxygen content <0.5ppm). The positive electrode, Celgard 2350 separator, negative electrode, stainless steel gasket, and stainless steel spring are then sequentially placed into a CR2032 button cell casing. 25μL of electrolyte (a 1M LiPF6 solution in the following mixed solvent: ethylene carbonate (EC) and diethyl carbonate (DEC) are mixed in a 1:1 volume ratio, and based on the total volume fraction of EC+DEC, 10% fluoroethylene carbonate (FEC) and 1% vinylene carbonate (VC) are added) are added. After stacking, hydraulic sealing is performed, and the cells are allowed to stand for 12 hours to allow the electrolyte to fully wet the electrode pores. Positive electrode 1 and negative electrode 1 form a full cell 1, and positive electrode 2 and negative electrode 2 form a full cell 2.

[0189] Charge-discharge cycle test: The prepared full cells 1 and 2 were first subjected to 3 charge-discharge cycles at a 0.1C rate to activate the electrode materials. The discharge cutoff voltage was 2.5V, and the charge cutoff voltage was 3.7V. After each charge or discharge cycle, the cells were allowed to stand for 5 minutes before proceeding to the next step. After activation, a 100-cycle charge-discharge test was conducted at a 0.5C rate (with the same charge-discharge cutoff voltages as the activation process).

[0190] The energy density of the full cell can be calculated from the measured discharge capacity and charge / discharge cutoff voltage, with the mass of the electrodes (including the current collector) as the denominator. For the discharge specific capacity, the discharge capacity of each cycle is used as the numerator, and the weight (dry weight) of the active material contained in the positive electrode active material layer of the battery is used as the denominator. The two are then divided to obtain the discharge specific capacity.

[0191] Figure 10 shows the changes in discharge specific capacity and energy density of full cell 1 and full cell 2 with the number of cycles. As can be seen from Figure 10, full cell 1 has a higher energy density throughout the entire cycle compared to full cell 2.

[0192] Furthermore, full cell 1 exhibits an initial discharge specific capacity of approximately 150 mAh / g, while full cell 2 only exhibits an initial discharge specific capacity of approximately 100 mAh / g. This is unexpected, as full cells 1 and 2 use the same positive electrode active material, and it would generally be assumed that their discharge specific capacities should be similar. However, the results show that full cell 1 has a significantly higher discharge specific capacity than full cell 2. This indicates that the electrode preparation method of the present invention is beneficial for improving the discharge specific capacity of the active material.

[0193] Example 8: Effect of electrodeposition temperature

[0194] Negative electrodes 9, 10, 11, and 12 were prepared using the same method as negative electrode 1 in Example 1, except that the electrodeposition temperatures were 70°C, 30°C, 10°C, and 0°C, respectively. They were then assembled into coin cells using the coin cell assembly method described in Example 1, and subjected to charge-discharge cycle tests at a 0.5C rate according to the method described in Example 7.

[0195] Figure 11 shows images of negative electrodes prepared at different electrodeposition temperatures, from left to right: negative electrode 9, negative electrode 10, negative electrode 11, and negative electrode 12.

[0196] The charge-discharge cycle test results of the button half-cell assembled from negative electrode 9, negative electrode 10, negative electrode 11 and negative electrode 12 are summarized in Table 8.

[0197] Table 8: Charge-discharge cycle test results of button half-cells

[0198] As shown in Table 8, the electrodeposition temperature has a significant impact on the discharge specific capacity and cycle performance of the coin half-cell assembled from the prepared electrodes. Surprisingly, as the electrodeposition temperature gradually decreases, the initial discharge specific capacity, the discharge specific capacity after 50 cycles, and the specific capacity retention of the coin half-cell assembled from the prepared electrodes all gradually increase. This indicates that a lower electrodeposition temperature is beneficial for improving the initial discharge specific capacity and cycle performance.

[0199] Example 9: Roughness of self-supporting electrode film

[0200] The self-supporting graphite electrode film with a surface roughness of 0.02 μm was prepared as follows: The self-supporting graphite electrode film prepared in Example 1 was extruded to the target parameters (surface roughness of 0.02 μm) via rollers.

[0201] A self-supporting graphite electrode film with a surface roughness of 0.2 μm was prepared as follows: The surface roughness of the self-supporting graphite electrode film prepared in Example 1 was adjusted to 0.2 μm by plasma etching under the following conditions: the process gas was argon, the argon gas rate was 40 sccm, the current was 0.1 A, the gas pressure was 2 mTorr, and the etching time was 300 s.

[0202] A mixed aqueous solution of 200 g / L copper sulfate pentahydrate, 20 g / L glucose, and 65 g / L sulfuric acid was prepared as the electrolyte for copper plating on the negative electrode surface. Self-supporting graphite electrode films with surface roughness of 0.02 μm and 0.2 μm were coated with insulating PE films on one side, and then immersed in the electrolyte along with copper foil. This was connected to a power source to form a two-electrode system, with the self-supporting graphite electrode film serving as the cathode and the copper foil as the anode. Electricity was used as the power source, with a current of 2.5 A / dm². 2 Electrodeposition was performed at a current density of 100 kJ / cm² at 0 °C for 100 seconds. Afterwards, the self-supporting graphite electrode film with the insulating PE film was removed, the insulating PE film was removed, and after drying, negative electrodes 13 (corresponding to a self-supporting graphite electrode film with a roughness of 0.02 μm) and 14 (corresponding to a self-supporting graphite electrode film with a roughness of 0.2 μm) with an electrodeposition current current thickness of 1 μm were obtained. Correspondingly, the self-supporting graphite electrode film was subjected to current density of 180 °C and 500 kgf / cm² for 100 seconds. 2 Under certain conditions, negative electrode 15 (corresponding to a self-supporting graphite electrode film with a roughness of 0.02 μm) and negative electrode 16 (corresponding to a self-supporting graphite electrode film with a roughness of 0.2 μm) were obtained by hot pressing and laminating with 9 μm carbon-coated copper foil (8 μm copper + 1 μm carbon, purchased from Shenzhen Kejing Company (MTI)).

[0203] The half-cell was assembled according to the method in Example 1 and subjected to 100 charge-discharge cycles at a rate of 0.5C. The test results are summarized in Table 9.

[0204] Table 9: Influence of Roughness

[0205] As shown in Table 9, for the self-supporting graphite electrode film with a surface roughness of 0.02 μm, the half-cell corresponding to the negative electrode 13 prepared by electrodeposition with the graphite film exhibits better performance in terms of initial specific capacity, remaining specific capacity after 100 cycles, and specific capacity retention than the negative electrode 15 prepared by hot-pressing. A similar trend can be observed in the comparison of negative electrodes 14 and 16, but compared to the case with a surface roughness of 0.02 μm, the method of the present invention shows a greater improvement in initial specific capacity and other properties compared to hot-pressing when the surface roughness is 0.2 μm.

[0206] Example 10: Application in Supercapacitors

[0207] Preparation of self-supporting activated carbon electrode film: The self-supporting activated carbon electrode film was prepared by the same method as the self-supporting graphite electrode film in Example 1, except that graphite was replaced with activated carbon (YP-80F).

[0208] Inside the glove box, aluminum chloride powder was added to the ionic liquid 1-ethyl-3-methylimidazolium chloride [EMIMCl] at a molar ratio of aluminum chloride to ionic liquid of 1.3:1. After stirring and dissolving, an electrolyte for aluminum plating was obtained. A self-supporting activated carbon electrode membrane prepared above was coated with an insulating PE film on one side and immersed in the electrolyte along with aluminum foil. This was connected to a power source to form a two-electrode system, with the self-supporting activated carbon electrode membrane serving as the cathode and the aluminum foil as the anode. Direct current was used as the power source, and a current of 3.5 A / dm² was applied. 2 Electrodeposition was performed at a current density of 180 kgf / cm² at 25°C for 180 seconds. Afterwards, the self-supporting activated carbon electrode film with the insulating PE film was removed, the insulating PE film was removed, and the electrode was dried to obtain electrode a with an electrodeposited current current thickness of 2 μm. Correspondingly, the self-supporting activated carbon electrode film was subjected to current density of 180°C and 500 kgf / cm² for 180 seconds. 2 Electrode b was fabricated by hot pressing a 16μm carbon-coated aluminum foil (15μm aluminum + 1μm carbon) with the substrate under the specified conditions.

[0209] Electrode a and electrode b were transferred out of the glove box, washed three times, and then vacuum dried overnight (80°C). The prepared electrodes a and b were then assembled into symmetrical supercapacitor 1 and supercapacitor 2, respectively, using a 6M KOH aqueous solution as the electrolyte.

[0210] According to the national standard GB / T34870.1-2017, the specific capacitance (with the mass of the active material excluding the current collector as the denominator) and energy density (with the mass of the electrode including the current collector as the denominator) of supercapacitor 1 and supercapacitor 2 are tested.

[0211] Table 10 lists the properties of electrode a and electrode b.

[0212] Table 10: Properties of Activated Carbon Electrodes

[0213] Table 11 lists some performance characteristics of Supercapacitor 1 and Supercapacitor 2.

[0214] Table 11: Performance of Supercapacitors

[0215] As can be seen from Table 11, supercapacitor 1 has a better specific capacitance than supercapacitor 2, which is also unexpected, as those skilled in the art would generally assume that the same active material would have the same specific capacitance. Furthermore, supercapacitor 1 has a higher energy density than supercapacitor 2.

[0216] Example 11: Application in sodium-ion batteries

[0217] Anode preparation:

[0218] Preparation of self-supporting hard carbon electrode film: Except for replacing the active material with hard carbon (e.g., Kuraray type-2), the preparation method of self-supporting hard carbon electrode film is the same as that of self-supporting graphite electrode film in Example 1.

[0219] A mixed aqueous solution of 200 g / L copper sulfate pentahydrate, 20 g / L glucose, and 65 g / L sulfuric acid was prepared as the electrolyte for copper plating on the negative electrode surface. An insulating PE film was attached to one side of a self-supporting hard carbon electrode film. The hard carbon film and copper foil were immersed together in the electrolyte and connected to a power source to form a two-electrode system, with the self-supporting hard carbon electrode film serving as the cathode and the copper foil as the anode. Direct current (DC) was used as the power source, with a current of 2.5 A / dm². 2 Electrodeposition was performed at a current density of 100 kJ / cm² at 0°C for 100 seconds. Afterwards, the self-supporting hard carbon electrode film with the insulating PE film was removed, the insulating PE film was removed, and after drying, a negative electrode 7 with an electrodeposited current current thickness of 1 μm was obtained. Correspondingly, the self-supporting hard carbon electrode film was subjected to current density of 180°C and 500 kgf / cm² for 100 seconds. 2 Under certain conditions, the negative electrode 8 was obtained by hot-pressing a 9μm carbon-coated copper foil (8μm copper + 1μm carbon).

[0220] Cathode preparation:

[0221] Preparation of self-supporting Prussian blue electrode film: Except for replacing the active material with Prussian blue (NaHCF), the preparation method of the self-supporting Prussian blue electrode film is the same as that of the self-supporting lithium iron phosphate electrode film in Example 7.

[0222] Inside the glove box, aluminum chloride powder was added to the ionic liquid 1-ethyl-3-methylimidazolium chloride [EMIMCl] at a molar ratio of aluminum chloride to ionic liquid of 1.3:1. After stirring and dissolving, an electrolyte for aluminum plating was obtained. A self-supporting Prussian blue electrode film with an insulating PE film attached to one side was immersed in the electrolyte along with aluminum foil, forming a two-electrode system connected to a power source. The self-supporting Prussian blue electrode film served as the cathode, and the aluminum foil as the anode. Direct current (DC) was used as the power source, with a current of 2.5 A / dm². 2 Electrodeposition was performed at a current density of 180 kgf / cm² at 25°C for 180 seconds. Afterwards, the self-supporting Prussian blue electrode film with the insulating PE film was removed, the insulating PE film was removed, and after drying, a positive electrode 3 with an electrodeposited current current thickness of 2 μm was obtained. Correspondingly, the self-supporting Prussian blue electrode film was subjected to current density of 180°C and 500 kgf / cm² for 180 seconds. 2 Under certain conditions, a positive electrode 4 was synthesized by hot pressing with a 16μm carbon-coated aluminum foil (15μm aluminum + 1μm carbon).

[0223] Sodium-ion battery assembly: Referring to the assembly method of lithium-ion battery in Example 7, negative electrode 7 and positive electrode 3, negative electrode 8 and positive electrode 4 are assembled into sodium-ion batteries 1 and 2 respectively in an argon-filled glove box, wherein the electrolyte is a 1M NaPF6 solution in DME (100 vol%).

[0224] Sodium-ion batteries 1 and 2 were tested according to the charge-discharge cycle test method for sodium-ion batteries in Example 7. The test results are summarized in Table 12.

[0225] Table 12: Performance Comparison of Sodium-ion Batteries

[0226] As can be seen from Table 12, sodium-ion battery 1 has significantly higher specific capacity of both the positive and negative electrode active materials than sodium-ion battery 2. This is unexpected, as it is generally accepted in the art that the same electrode active materials will have the same specific capacity. Furthermore, sodium-ion battery 1 has a higher energy density than sodium-ion battery 2.

[0227] The above description is merely an exemplary embodiment of the present invention. It should be noted that those skilled in the art can make improvements to the present invention without departing from the inventive concept, and all such improvements fall within the scope of protection of the present invention.

Claims

1. A method for preparing an electrode, comprising: (a) A self-supporting electrode film is provided, comprising a first side and a second side opposite to the first side, the second side comprising a region thereon on which metal is to be deposited when in contact with an electrolyte to perform an electrodeposition reaction; (b) Provide an electrolyte containing a salt of the metal to be deposited; (c) At least the region to be deposited on the second side of the self-supporting electrode film is brought into contact with the electrolyte, and an electrodeposition reaction is performed in the region to be deposited to deposit a current collector of the metal to be deposited on the second side, wherein the electrodeposition temperature is 0 to 70°C, preferably 0 to 30°C, more preferably 0 to 20°C, and even more preferably 0 to 10°C.

2. The method according to claim 1, wherein step (a) further comprises providing an auxiliary conductor on at least a portion or all of a first region on a first side of the self-supporting electrode film, the first region being a corresponding region opposite to the region to be deposited on the second side, the auxiliary conductor contacting the first region during electrodeposition.

3. The method of claim 2, wherein the auxiliary conductor is selected from metal foil, such as copper foil or aluminum foil, and step (a) optionally includes providing a protective layer on at least the first region on the first side of the self-supporting electrode film, the protective layer being used to protect the first side from depositing current collectors during electrodeposition, the method further comprising removing the auxiliary conductor and optionally the protective layer after electrodeposition is completed.

4. The method of claim 2, wherein the auxiliary conductor is selected from a conductive roller, and all or at least the surface of the conductive roller is made of a metal such as copper or aluminum.

5. The method according to any one of claims 1 to 4, wherein the self-supporting electrode film is a positive electrode film, and the metal to be deposited is aluminum.

6. The method according to any one of claims 1 to 4, wherein the self-supporting electrode film is a negative electrode film, and the metal to be deposited is copper.

7. The method according to any one of claims 1 to 6, wherein one or more of the following conditions are satisfied: (i) The surface roughness of the self-supporting electrode film is 0.02-0.50 μm, for example, 0.02-0.20 μm; (ii) The protective layer is made of one or more materials selected from polyimide (PI), polyethylene (PE), polypropylene (PP), and polytetrafluoroethylene (PTFE); (iii) The electrolyte is an aqueous or non-aqueous system and includes: a solvent; a salt containing the metal to be deposited; and optionally one or more of a leveling agent, brightener, stabilizer, acid, or base. Preferably, when the electrolyte is an aqueous system, the solvent includes water and optionally further includes an organic solvent miscible with water; When the electrolyte is a non-aqueous system, the electrolyte includes organic solvents and / or ionic liquids; Preferably, the organic solvent is selected from one or more of ethers such as tetrahydrofuran, aromatic hydrocarbons, and their derivatives; and / or the ionic liquid is selected from one or more of haloalkylpyridines, haloalkylimidazolines, or haloalkylarylammonium salts. Preferably, during electrodeposition, the self-supporting electrode film is used as the cathode and a metal foil containing the metal to be deposited, such as the metal foil containing the metal to be deposited, is used as the anode.

8. The method according to any one of claims 1 to 7, wherein the process conditions during electrodeposition of the current collector further include one or more of the following: the current is selected from any one of DC constant current, pulse, square wave, triangular wave, sine wave, or a superposition thereof; the current density is 0.1-10 A / dm³. 2 The electrodeposition time is 30-1800 seconds; and the thickness of the electrodeposited current collector is 0.1-20 μm.

9. The method according to any one of claims 1 to 8, wherein one or more of the following are satisfied: (iv) Step (a) further includes washing the self-supporting electrode film with a solvent and / or purging the self-supporting electrode film with an airflow; (v) Step (a) further includes bringing the self-supporting electrode film into a charged state; or (vi) Step (a) further includes surface treatment of the self-supporting electrode film using plasma.

10. An electrode prepared by the method according to any one of claims 1 to 9.

11. An energy storage device comprising the electrode according to claim 10.

12. The energy storage device according to claim 11, wherein any one of the following conditions is met: (vii) The energy storage device is a lithium-ion secondary battery. Preferably, the positive electrode active material is selected from one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium phosphates with an olivine structure, preferably LiMn2O4, LiNiMnCoO2, and LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.5 Co 0.3 Mn 0.2 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 One or more of O2 and LiFePO4, Preferably, the negative electrode active material is selected from one or more of natural graphite, artificial graphite, mesophase microcarbon spheres (MCMB), hard carbon, soft carbon, silicon-based materials, tin-based materials, lithium titanate, and lithium metal; more preferably, one or more of graphite and silicon-based materials; and more preferably, one or more of graphite, silicon-carbon composites, and silicon alloys; or (viii) The energy storage device is a sodium-ion secondary battery. Preferably, the positive electrode active material is selected from one or more of layered transition metal oxides or Prussian blue analogues, preferably NaNi. 1 / 3 Fe 1 / 3 Mn 1 / 3 One or more of the following: O2, Na2FeP2O7, Na4Fe3(PO4)2(P2O7), Na3V2(PO4)3, NaFePO4, and NaMnFe(CN)6 Preferably, the negative electrode active material is selected from one or more of natural graphite, artificial graphite, mesophase microcarbon spheres (MCMB), hard carbon, soft carbon, silicon-based materials, and tin-based materials; more preferably, one or more of graphite and silicon-based materials; and even more preferably, one or more of graphite, silicon-carbon composites, and silicon alloys; or (ix) The energy storage device is a supercapacitor. Preferably, the positive electrode active material is selected from one or more of metal oxides, conductive polymers, and carbon materials, and more preferably from one or more of MnO2, NiO, Co3O4, polyaniline, polypyrrole, activated carbon, graphene, and biochar. Preferably, the negative electrode active material is selected from one or more of metals, carbon materials, conductive polymers, metal oxides, and metal-organic framework (MOF) derived materials, and more preferably from one or more of aluminum, zinc, activated carbon, graphite, polyaniline, polypyrrole, polythiophene, and MnO2.

13. An electrode production system for performing the method according to any one of claims 1-9, comprising: A self-supporting electrode film providing module is used to provide a self-supporting electrode film, the self-supporting electrode film including a first side and a second side opposite to the first side, the second side including a region to be deposited thereon on which metal is deposited when in contact with an electrolyte to perform an electrodeposition reaction; An optional surface cleaning and treatment module, located upstream of the electrodeposition module, is used to clean and treat the surface of the self-supporting electrode film. An electrolyte supply module is used to supply an electrolyte for electrodeposition to the electrodeposition module; A temperature control module is used to control the temperature of the electrodeposition module to control the electrodeposition temperature to 0 to 70°C, preferably 0 to 30°C, more preferably 0 to 20°C, and even more preferably 0 to 10°C; An electrodeposition module, located downstream of the self-supporting electrode film supply module and the electrolyte supply module, is used to deposit a current collector on the second side of the self-supporting electrode film. An optional cleaning and drying module, located downstream of the electrodeposition module, is used to clean and dry the prepared electrodes. A drive module is used to move the self-supporting electrode film between various modules of the electrode production system. and An optional collection and delivery module is used to collect and deliver the prepared electrodes.

14. The electrode production system of claim 13 further includes an optional auxiliary conductor setting module, located downstream of the self-supporting electrode film providing module and the optional surface cleaning and treatment module and upstream of the electrodeposition module, for setting an auxiliary conductor on at least a portion or all of a first region on a first side of the self-supporting electrode film, the first region being a corresponding region opposite to the region to be deposited on the second side, wherein the auxiliary conductor contacts the first region during electrodeposition.

15. The electrode production system according to claim 14, further comprising: An optional protective layer setting module, located downstream of the self-supporting electrode film providing module and the optional auxiliary conductor setting module and upstream of the electrodeposition module, is used to set a protective layer on at least the first region on the first side of the self-supporting electrode film, the protective layer being used to protect the first side from depositing current collectors during the electrodeposition process. An optional separation module, located downstream of the electrodeposition module, is used to remove an optional auxiliary conductor and an optional protective layer; An optional protective layer circulation module, located downstream of the optional separation module, is used to transfer the separated protective layer to the optional protective layer setting module for reuse; and An optional rolling module comprising a first part and an optional second part, wherein the first part is located upstream of the self-supporting electrode film providing module for rolling the self-supporting electrode film, and the optional second part is located downstream of the optional separation module for rolling the resulting electrode.

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