Lithium battery pole piece and preparation process thereof

Abstract

The application provides a lithium battery pole piece and a preparation process thereof, relates to the technical field of lithium batteries, and discloses a coating layer, which is coated on the center of at least one surface of a current collector; side coating layers, which are coated on both sides of at least one surface of the current collector; and the side coating layers cover the positions connected with the current collector on both sides of the coating layer by 0.1mm-10mm, and the overlapping area of the side coating layers and the coating layer forms a covering layer; a chemically cross-linked water-insoluble polymer, N-methyl pyrrolidone or deionized water, and a coloring agent; the chemically cross-linked water-insoluble polymer is selected from fluoroplastic, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVF), and an insulating side coating adhesive, which is more flexible than a traditional boehmite side coating layer, can improve the tensile resistance of the current collector, and generates less dust in the production process.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to a lithium battery electrode and its preparation process. Background Technology

[0002] Existing lithium-ion battery electrodes mainly consist of a current collector, an active material layer, and an edge functional layer. Generally, aluminum foil or carbon-coated aluminum foil is used as the current collector for the positive electrode, and copper foil is used as the current collector for the negative electrode.

[0003] Applying an edge reinforcement layer to the edges of lithium-ion battery electrodes not only enhances their compressive strength but also reduces the risk of short circuits. Traditional edge coatings primarily use boehmite as their raw material, but these coatings have poor tensile strength and are prone to generating dust, burrs, or molten beads during edge processing, leading to serious safety hazards in subsequent cell production and application. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the tensile toughness of traditional edge coatings is poor, and the edge processing process is prone to generating a lot of dust, burrs or molten beads. In view of the problems existing in the prior art, a lithium battery electrode is provided.

[0005] To address the problems of existing technologies, this invention discloses a lithium battery electrode, comprising: a current collector, a coating layer, and an edge coating layer having an insulating adhesive material;

[0006] A coating layer is applied to the center of at least one surface of the current collector;

[0007] Specifically, the coating layer can be applied continuously or intermittently.

[0008] As an improvement to the safety battery electrode sheet described in this invention, an edge coating is also included:

[0009] An edge coating is applied to both sides of at least one surface of the current collector;

[0010] Specifically, the edge coating material is selected from: chemically cross-linked water-insoluble polymers, N-methylpyrrolidone or deionized water, and colorants;

[0011] Furthermore, the chemically crosslinked water-insoluble polymer is selected from one and / or more of the following: fluoroplastics, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVF), polytetrafluoroethylene (PTFE), perfluoroethylene propylene (FRP), soluble polytetrafluoroethylene (PFA), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), ethylene-tetrachloroethylene copolymer (ETFE), polyimide resin (PI), cyclic olefin copolymer (COC), polyacrylic acid or styrene-butadiene rubber or polyamide or polyterephthalate, their derivatives, their crosslinks and their copolymers;

[0012] Furthermore, the colorant is selected from one or more of the following: carbon black, cobalt blue, ultramarine, iron oxide, cadmium red, chrome orange, molybdenum orange, cadmium yellow, chrome yellow, nickel titanium yellow, titanium dioxide, zinc barium white, zinc white, phthalocyanine pigments, azo pigments, anthraquinone pigments, indigo pigments, and metal complex pigments.

[0013] The preparation method of the edge coating in the above-mentioned safety battery electrode sheet specifically includes the following steps:

[0014] S1: Glue making

[0015] Take a chemically cross-linked water-insoluble polymer, N-methylpyrrolidone or deionized water, and a colorant. The chemically cross-linked water-insoluble polymer is fluoroplastic, with a fluoroplastic ratio of 5%-30% and an N-methylpyrrolidone or deionized water ratio of 70%-95%. Place the prepared material into a mixer at room temperature and in a high dew point environment and stir to form an adhesive for 2-4 hours to obtain an insulating edge coating.

[0016] S2: Apply adhesive and color to the insulating edges.

[0017] After the stirring time is over, add 0.2%-1% of colorant, add the colorant to the mixer and mix it with the insulating edge coating obtained in S1. Stir again for 2-4 hours. After the stirring time is over, the colored insulating edge coating is obtained.

[0018] This design uses a coating device to apply colored insulating edge coating to both sides of the current collector, forming an edge coating. Compared with traditional boehm edge coating, the pure adhesive edge coating has better tensile strength and generates less dust during production, which is beneficial for maintaining the production environment. The edge coating position of the current collector is smoother and less prone to burrs and molten beads. The main function of the colorant is to make the insulating edge coating color visible, which makes it easier for the subsequent lithium battery processing section to identify the position of the edge coating.

[0019] Furthermore, the edge coating of the insulating adhesive material can significantly reduce the breakage rate of the electrode sheet during the later stages of transmission and rolling.

[0020] Furthermore, the edge coating layer covers the positions on both sides of the coating layer where it connects with the current collector by 0.1mm-10mm, and the overlapping area of ​​the edge coating layer and the coating layer forms a cover layer;

[0021] Furthermore, the thickness of the edge coating is 1μm-30μm, and the width of the cover layer is 0.1mm-2mm;

[0022] In this design, the coating layer is an active material layer, and the edge coating part is pressed against the edge of the coating layer and the current collector coating position, pressing the edge of the coating layer to prevent the active material of the coating layer from shedding powder and detaching from the current collector, thereby improving the stability of the connection between the active material and the current collector.

[0023] Further benefits include the ability of insulating edge coating to prevent burrs generated during the current collector cutting process from piercing the diaphragm, thus improving the problems of traditional boehm edge coating and ceramic coating being brittle after drying and ceramic particles easily causing belt breakage during rolling, resulting in a large amount of waste. Using insulating edge coating can improve production efficiency.

[0024] Compared to electrodes coated with boehmite edge coating and ceramic coating, electrodes coated with insulating edge coating have a significantly lower burr detection rate during die cutting. Furthermore, when the battery temperature rises due to overcharging or impact, the edge coating increases the battery's contact resistance at high temperatures, thus providing insulation and resulting in better safety and stability.

[0025] Several tabs are cut out on both sides of the current collector by a die-cutting device, and the edge coating extends to the root of the tab by 1μm-30μm. The edge coating extends to the tab to form a traction part.

[0026] More specifically, after the current collector undergoes the die-cutting process, several tabs are left on both sides of the current collector, and part of the edge coating will remain at the root of the tab. The edge coating of the insulating adhesive material can hold the root of the tab, which can prevent the tab from breaking and greatly improve the anti-wrinkle effect. In multiple processing steps, it is beneficial to protect the connection between the root of the tab and the current collector and reduce the output rate of defective products.

[0027] As an improvement to the safety-type battery electrode of the present invention, a composite current collector is also included:

[0028] The current collector includes two substrates arranged vertically and vertically and a composite layer disposed between the substrates. The composite layer is a sandwich between the two substrates, and the substrates and the composite layer are bonded together by an adhesive.

[0029] Preferably, the composite layer is selected from conductive polymer materials, and the conductive polymer material is polyethylene terephthalate or polybutylene terephthalate;

[0030] Furthermore, the surface of the current collector has several through holes;

[0031] Furthermore, a welding point is provided between the two substrate layers, and the welding point is the edge of a through hole in one of the substrate layers;

[0032] The method for preparing the current collector in the aforementioned safety battery electrode includes the following steps:

[0033] S1: First, use an adhesive to initially bond the two substrates to the composite layer. The substrates can be aluminum foil or copper foil. When aluminum foil is used, it is used as the positive current collector, while when copper foil is used, it is used as the negative current collector.

[0034] S2: Then, the current collector obtained in step S1 is pressed by external pressure, wherein the pressure source includes but is not limited to rolling, stamping or pressing, to obtain a composite current collector electrode.

[0035] S3: A through hole is drilled on the surface of the current collector electrode. The drilling method includes, but is not limited to, punching, stamping or drilling. The through hole passes through the substrate and the composite layer. The substrate that is drilled is partially broken and deformed by the stress of the punching and enters the through hole to form a tube. The end of the substrate extension extends to another substrate layer to form a welding point.

[0036] S4: The welding point is welded to the edge of the through hole in another substrate by means of vacuum electroplating or laser dot matrix welding, thus completing the welding between the two substrates. Vacuum electroplating methods include, but are not limited to, magnetron sputtering, vacuum evaporation, ion plating and other electroplating methods.

[0037] In this design, the outer contour of the tube end formed by drilling holes in the substrate is welded around the entire perimeter. The weld points are circular, and the large area of ​​the connection between the substrates facilitates the transition between the two substrate layers. The two substrate layers are connected through the substrate positions that deform due to the stress caused by drilling. The welding stability is high, and the welding stability of the same materials is also high. Furthermore, in mass production, the consistency of the composite current collector can be guaranteed.

[0038] The current collector further includes a support layer disposed between the current collector and the coating layer, and the support layer is at least one of conductive carbon material and metal material; wherein, the conductive carbon material is selected from zero-dimensional conductive carbon, including acetylene black and conductive carbon black; one-dimensional conductive carbon, including carbon nanotubes; two-dimensional conductive carbon, including conductive graphite and graphene; three-dimensional conductive carbon, including at least one of reduced graphene oxide; and the metal material is selected from at least one of aluminum powder, iron powder and silver powder.

[0039] Specifically, a support layer is coated onto the current collector to form a carbon-coated foil, and the support layer is preferably made of conductive carbon material. The support layer can improve the electron transmission efficiency. The current collector foil before coating can be called a smooth foil. If the coating layer is directly coated onto the surface of the smooth foil, the smooth surface of the smooth foil will result in high impedance when the coating layer is directly attached to the surface of the foil, and the coating layer is prone to powdering. If the support layer is first coated onto the smooth foil to form a carbon-coated foil, then friction is generated between the coating layer and the support layer during coating, and the coating between the coating layer and the current collector can be more compact, improving the coating quality.

[0040] Compared with the prior art, the beneficial effects of the present invention are:

[0041] 1. The support layer is first coated onto the optical foil to form a carbon-coated foil. During the coating process, friction is generated between the support layer and the coating layer, which allows for a tighter coating between the coating layer and the current collector, thus improving the coating quality.

[0042] 2. Compared with traditional boehm edge coating, insulating edge coating is more resilient, which can improve the tensile strength of the current collector. In addition, insulating edge coating generates less dust during the production process, which is conducive to maintaining the production environment. The edge coating position of the current collector is smoother and less prone to burrs and molten beads. The main function of the colorant is to make the insulating edge coating color, so that the edge coating position can be easily identified by the subsequent lithium battery processing section.

[0043] 3. The edge coating is pressed against the edge of the coating layer and the current collector, pressing the edge of the coating layer to prevent the active material of the coating layer from shedding powder and detaching from the current collector, thereby improving the stability of the connection between the active material and the current collector.

[0044] 4. The insulating edge coating can prevent burrs generated during the current collector cutting process from piercing the diaphragm, improving the problems of traditional boehm stone edge coating and ceramic coating being brittle after drying, and ceramic particles easily causing belt breakage during rolling, resulting in a lot of waste.

[0045] Compared to electrodes coated with boehmite edge coating and ceramic coating, electrodes coated with insulating edge coating have a significantly lower burr detection rate during die cutting. Furthermore, when the battery temperature rises due to overcharging or impact, the edge coating increases the battery's contact resistance at high temperatures, thus providing insulation and resulting in better safety and stability.

[0046] 5. Part of the edge coating is left at the root of the tab. The edge coating of insulating adhesive material can hold the root of the tab in place, preventing the tab from breaking and greatly improving the anti-wrinkle effect of the electrode. In multiple processing steps, it helps to protect the connection between the root of the tab and the current collector, reducing the yield of defective products.

[0047] 6. The composite layer is made of conductive film materials such as polyethylene terephthalate or polybutylene terephthalate. As an interlayer, the composite layer has good tensile properties. When the composite microporous foil is used in the production of battery cells, the tensile strength of the current collector can be improved and the tension of the current collector can be strengthened through the composite interlayer. This can improve the quality of battery cell materials and effectively avoid the problem of traditional foils being prone to breakage and affecting production. The microporous composite foil is not easy to crack and can also solve the problem that the tensile strength of traditional foils is too low to support coating.

[0048] The two substrate layers are stably conductive through the tube section, which helps to enhance conductivity and ensure the stable operation of the battery cell;

[0049] Furthermore, when the battery cell generates high temperatures during operation, the composite layer will melt due to the high temperature, reducing the conductivity of the electrode and decreasing the possibility of the battery cell catching fire. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0051] Figure 2 This is a schematic diagram of the surface of the current collector structure of the present invention (after slicing).

[0052] Figure 3 for Figure 2 A magnified schematic diagram of the electrode structure of the current collector;

[0053] Figure 4 This is a schematic cross-sectional view of the current collector structure of the present invention;

[0054] Figure 5 This is a schematic diagram of the substrate and composite layer structure of the present invention (with holes already drilled).

[0055] Figure 6 This is a cross-sectional schematic diagram of the substrate and composite layer combination structure of the present invention.

[0056] The markings in the figure are: current collector (1), composite layer (101), substrate (102), coating layer (2), edge coating layer (3), cover layer (4), support layer (5), and tab (6). Detailed Implementation

[0057] To better understand the above-mentioned objects, features, and advantages of the present invention, the following description is provided in conjunction with the accompanying drawings. Figures 1-6 The present invention will be further described in detail below with reference to specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0058] Example 1:

[0059] Please see Figure 4A lithium battery electrode includes: a current collector and a coating layer;

[0060] The current collector further includes a support layer disposed between the current collector and the coating layer, and the support layer is at least one of conductive carbon material and metal material; wherein, the conductive carbon material is selected from zero-dimensional conductive carbon, including acetylene black and conductive carbon black; one-dimensional conductive carbon, including carbon nanotubes; two-dimensional conductive carbon, including conductive graphite and graphene; three-dimensional conductive carbon, including at least one of reduced graphene oxide; and the metal material is selected from at least one of aluminum powder, iron powder and silver powder.

[0061] Furthermore, a support layer is coated onto the current collector to form a carbon-coated foil. The support layer is preferably made of conductive carbon material. The support layer can improve the electron transmission efficiency. The current collector foil before coating can be called a smooth foil. Because the surface of the smooth foil is smooth, if the coating layer is directly coated onto the surface of the smooth foil, the impedance of the coating layer when it is directly attached to the surface of the foil will increase, and the coating layer will easily shed powder. If the support layer is first coated onto the smooth foil to form a carbon-coated foil, then friction will be generated between the coating layer and the support layer during coating. The coating between the coating layer and the current collector can be more compact, improving the coating quality.

[0062] Please see Figure 1 , Figure 2 and Figure 4 When the current collector is aluminum foil, the coating layer is the positive electrode active material layer;

[0063] When the current collector is copper foil, the coating layer is the negative electrode active material layer;

[0064] A coating layer is applied to the center of at least one surface of the current collector;

[0065] Specifically, the coating layer can be applied continuously or intermittently.

[0066] As an improvement to the safety-type battery electrode sheet described in this invention, it also includes an edge coating with an insulating adhesive material:

[0067] An edge coating is applied to both sides of at least one surface of the current collector;

[0068] Specifically, the edge coating material is selected from: chemically cross-linked water-insoluble polymers, N-methylpyrrolidone or deionized water, and colorants;

[0069] Furthermore, the chemically crosslinked water-insoluble polymer is selected from one and / or more of the following: fluoroplastics, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVF), polytetrafluoroethylene (PTFE), perfluoroethylene propylene (FRP), soluble polytetrafluoroethylene (PFA), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), ethylene-tetrachloroethylene copolymer (ETFE), polyimide resin (PI), cyclic olefin copolymer (COC), polyacrylic acid or styrene-butadiene rubber or polyamide or polyterephthalate, their derivatives, their crosslinks and their copolymers;

[0070] Furthermore, the colorant is selected from one or more of the following: carbon black, cobalt blue, ultramarine, iron oxide, cadmium red, chrome orange, molybdenum orange, cadmium yellow, chrome yellow, nickel titanium yellow, titanium dioxide, zinc barium white, zinc white, phthalocyanine pigments, azo pigments, anthraquinone pigments, indigo pigments, and metal complex pigments.

[0071] The preparation method of the edge coating in the above-mentioned safety battery electrode includes the following steps:

[0072] S1: Glue making

[0073] Take a chemically cross-linked water-insoluble polymer, N-methylpyrrolidone or deionized water, and a colorant. The chemically cross-linked water-insoluble polymer is fluoroplastic, with a fluoroplastic ratio of 5%-30% and an N-methylpyrrolidone or deionized water ratio of 70%-95%. Place the prepared material into a mixer at room temperature and in a high dew point environment and stir to form an adhesive for 2-4 hours to obtain an insulating edge coating.

[0074] S2: Coloring of the adhesive

[0075] After the stirring time is over, add 0.2%-1% of colorant and mix it with the insulating edge coating obtained in S1 in the mixer. Stir again for 2-4 hours. After the stirring time is over, the colored insulating edge coating is obtained.

[0076] Edge coating process:

[0077] Colored insulating edge coating is applied to both sides of the current collector using continuous or intermittent coating equipment to form an edge coating layer;

[0078] Furthermore, the insulating edge coating is more resilient than the traditional boehm edge coating, which can improve the tensile strength of the current collector. The insulating edge coating also generates less dust during the production process, which is beneficial to maintaining the production environment. The edge coating of the current collector is smoother and less prone to burrs and molten beads. The main function of the colorant is to make the insulating edge coating color, which makes it easier for the subsequent lithium battery processing section to identify the edge coating position.

[0079] Applying adhesive to the insulating edges during the later stages of transmission and rolling can significantly reduce the breakage rate of the electrode sheets.

[0080] Furthermore, the edge coating covers the two sides of the coating layer at the connection points with the current collector by 0.1mm-10mm, and the overlapping area of ​​the edge coating and the coating layer forms a cover layer;

[0081] In this design, the coating layer is an active material layer, and the edge coating part is pressed against the edge of the coating layer and the current collector coating position to press the edge of the coating layer in place, so as to prevent the active material of the coating layer from shedding powder and detaching from the current collector, thereby improving the stability of the connection between the active material and the current collector.

[0082] Furthermore, the thickness of the edge coating is 1μm-30μm, and the width of the cover layer is 0.1mm-2mm;

[0083] Further benefits include the ability of insulating edge coating to prevent burrs generated during the current collector cutting process from piercing the diaphragm, thus improving the problems of traditional boehm edge coating and ceramic coating being brittle after drying and ceramic particles easily causing belt breakage during rolling, resulting in a large amount of waste. Using insulating edge coating can improve production efficiency.

[0084] Compared to electrodes coated with boehmite edge coating and ceramic coating, electrodes coated with insulating edge coating have a significantly lower burr detection rate during die cutting. Furthermore, when the battery temperature rises due to overcharging or impact, the edge coating increases the battery's contact resistance at high temperatures, thus providing insulation and resulting in better safety and stability.

[0085] Please see Figures 1-4 Current collector die-cutting tab steps:

[0086] Several tabs are cut out on both sides of the current collector using a die-cutting device, and the edge coating extends to the root of the tab by 1μm-30μm (e.g. Figure 3 As shown), the edge coating extends to the position of the electrode tab to form a traction section;

[0087] Furthermore, after the current collector undergoes the die-cutting process, several tabs are left on both sides, and part of the edge coating will remain at the root of the tab. The edge coating of the insulating adhesive material can hold the root of the tab in place, preventing the tab from breaking and greatly improving the anti-wrinkle effect of the electrode sheet. In multiple processing steps, this helps to protect the connection between the root of the tab and the current collector, reducing the yield of defective products.

[0088] Example 2:

[0089] Please see Figures 1-6 The current collector includes two substrates arranged vertically and vertically and a composite layer disposed between the substrates. The composite layer is a sandwich between the two substrates, and the substrates and the composite layer are bonded together by an adhesive.

[0090] Furthermore, the surface of the current collector has several through holes.

[0091] Furthermore, a welding point is provided between the two substrate layers, and the welding point is the edge of a through hole in one of the substrate layers;

[0092] The difference between this embodiment and Embodiment 1 is that the current collector used in Embodiment 1 was a carbon-coated foil, while this embodiment provides a composite foil, the specific preparation method of which is as follows:

[0093] S1: First, use an adhesive to initially bond the two substrates to the composite layer. The substrates can be aluminum foil or copper foil. When aluminum foil is used, it is used as the positive current collector, while when copper foil is used, it is used as the negative current collector.

[0094] S2: Then, the current collector obtained in step S1 is pressed by external pressure. The composite layer is selected from conductive polymer materials, such as polyethylene terephthalate or polybutylene terephthalate. The external pressure sources include, but are not limited to, rolling, stamping or pressing, to obtain a composite current collector electrode.

[0095] S3: A through hole is drilled on the surface of the current collector electrode. The drilling method includes, but is not limited to, punching, stamping, or drilling. The through hole penetrates the substrate and the composite layer. The substrate is partially broken and deformed by the stress of the punching and drilling, thus entering the through hole and forming a tubular shape (e.g., Figure 6 As shown), the end of the substrate extension extends to another substrate layer to form a welding point;

[0096] S4: The welding point is welded to the edge of the through hole in another substrate by means of vacuum electroplating or laser dot matrix welding, thus completing the welding between the two substrates. Vacuum electroplating methods include, but are not limited to, magnetron sputtering, vacuum evaporation, ion plating and other electroplating methods.

[0097] In this design, the outer contour of the tube end formed by drilling holes in the substrate is welded around the entire perimeter. The weld points are circular, and the large area of ​​the connection between the substrates facilitates the transition between the two substrate layers. The two substrate layers are connected through the tube position that deforms due to the stress caused by drilling. The welding stability is high, and the welding stability of the same materials is also high. Especially in mass production, it can ensure the consistency of the composite current collector.

[0098] A composite microporous foil current collector was prepared according to the above method. The coating methods for the support layer, coating layer, and edge coating layer of the current collector were the same as those in Example 1. The difference was that the carbon-coated foil was prepared as a composite microporous foil. The composite layer was a conductive film material such as polyethylene terephthalate or polybutylene terephthalate. As an interlayer, the composite layer had good tensile properties. When the composite microporous foil was used in the production of battery cells, the tensile strength of the current collector could be improved and the tension of the current collector could be strengthened through the interlayer of the composite layer. This could improve the quality of the battery cell material and effectively avoid the problem of traditional foil breaking easily and affecting production. The microporous composite foil was not easy to crack and could also solve the problem that the tensile strength of traditional foil was too low to support coating.

[0099] The two substrate layers are stably conductive through the tube section, which helps to enhance conductivity and ensure the stable operation of the battery cell;

[0100] Furthermore, when the battery cell generates high temperatures during operation, the composite layer will melt due to the high temperature, reducing the conductivity of the electrode and decreasing the possibility of the battery cell catching fire.

[0101] Furthermore, the composite microporous foil material of this invention can be used for batteries such as lithium iron phosphate, lithium cobalt oxide, or lithium manganese oxide. In particular, lithium cobalt oxide batteries have a higher capacity than lithium iron phosphate batteries, and their charging and discharging structure is prone to change, resulting in low safety performance. Using this composite microporous foil material can effectively protect the battery from short circuits, thereby improving the battery safety performance.

[0102] The present invention has been described in the above-described embodiments; however, these embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the present invention. Conversely, any modifications and refinements made without departing from the spirit and scope of the present invention are within the scope of patent protection of the present invention.

Claims

1. A process for preparing lithium battery electrodes, characterized in that, Lithium-ion battery electrodes include: Current collector, coating layer and edge coating with insulating adhesive material; A coating layer is applied to the center of at least one surface of the current collector; An edge coating is applied to both sides of at least one surface of the current collector; Furthermore, the edge coating covers the positions where the coating layer connects to the current collector on both sides by 0.1mm-10mm, and the overlapping area of ​​the edge coating layer and the coating layer forms a cover layer; The current collector comprises two substrate layers arranged vertically and a composite layer disposed between the substrate layers, wherein the composite layer is a sandwich layer between the two substrate layers, and the substrate layers and the composite layer are bonded together by an adhesive; the manufacturing process of the lithium battery electrode includes the following steps: S1: Prepare the current collector; S2: Preparation of coating slurry and edge coating slurry; S3: The prepared coating slurry and edge coating slurry are simultaneously coated onto the surface of the current collector using a coating equipment; S1 includes the following steps: S11: First, use an adhesive to initially bond the two substrates to the composite layer. The substrates are aluminum foil or copper foil. When aluminum foil is used, it is used as the positive current collector, and when copper foil is used, it is used as the negative current collector. S12: Then, the current collector obtained in step S1 is pressed by external pressure, where the pressure comes from rolling, stamping or pressing, to obtain a composite current collector electrode. S13: A through hole is punched on the surface of the current collector electrode. The punching method includes punching, stamping or drilling. The through hole passes through the substrate and the composite layer. The substrate that is punched is partially broken and deformed by the stress of punching and drilling, and enters the through hole to form a tube. The end of the substrate extension extends to another substrate layer to form a welding point. S14: The welding between the two substrates is completed by using vacuum electroplating or laser dot matrix welding to weld the welding spot to the edge of the through hole in another substrate. Vacuum electroplating methods include magnetron sputtering, vacuum evaporation, and ion plating.

2. The process for preparing a lithium battery electrode according to claim 1, characterized in that: The edge coating material comprises a chemically cross-linked water-insoluble polymer, N-methylpyrrolidone, and a colorant.

3. The process for preparing a lithium battery electrode according to claim 2, characterized in that: The colorants include one or more of the following: carbon black, cobalt blue, ultramarine, iron oxide, cadmium red, chrome orange, molybdenum orange, cadmium yellow, chrome yellow, nickel titanium yellow, titanium dioxide, zinc barium white, zinc white, phthalocyanine pigments, azo pigments, anthraquinone pigments, indigo pigments, and metal complex pigments.

4. The process for preparing a lithium battery electrode according to claim 1, characterized in that: The thickness of the edge coating is 1μm-30μm, and the width of the cover layer is 0.1mm-2mm.

5. The process for preparing a lithium battery electrode according to claim 1, characterized in that: Several tabs are cut out on both sides of the current collector by a die-cutting device, and the edge coating extends to the root of the tab by 1μm-30μm, and the edge coating extends to the position of the tab to form a traction part.

6. The process for preparing a lithium battery electrode according to claim 1, characterized in that: The current collector further includes a support layer disposed between the current collector and the coating layer, and the support layer is at least one of conductive carbon material and metal material; wherein, the conductive carbon material includes zero-dimensional conductive carbon, including conductive carbon black; one-dimensional conductive carbon, including carbon nanotubes; two-dimensional conductive carbon, including conductive graphite and graphene; three-dimensional conductive carbon, including at least one of reduced graphene oxide; and the metal material includes at least one of aluminum powder, iron powder and silver powder.

7. A lithium battery electrode, characterized in that, The electrode is prepared using a process described in any one of claims 1-6 for lithium-ion batteries.

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