Battery electrode, battery, battery pack, electric vehicle and electrical appliance

Abstract

Battery electrode, battery, battery pack, electric vehicle, and electrical appliance. The present invention relates to a battery electrode, which is characterized in that it includes a conductive substrate, an active material layer covering the conductive substrate; a tab, the tab extending from the edge of the conductive substrate; and a conductive agent layer, the conductive agent layer being provided between the conductive substrate and the active material layer, the conductive agent layer only covering a partial area of the active material region, and the active material region refers to the region of the conductive substrate covered by the active material layer; wherein, the active material layer and the conductive agent layer abut against the tab, and the conductive agent layer penetrates through the active material region. The battery electrode is used for a battery and can improve the energy density of the battery.

Description

Technical Field

[0001] The present invention relates to the field of power supplies, and particularly to a battery electrode, a battery, a battery pack, an electric vehicle, and an electrical appliance. Background Art

[0002] Electric vehicles mainly use electricity instead of oil to drive the power system, including pure electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles.

[0003] Electric vehicles use batteries as the power source. Improving the energy density of the battery is equivalent to increasing the electricity storage capacity of the electric vehicle, which in turn helps to improve the endurance of the electric vehicle. Summary of the Invention

[0004] One technical problem solved by the present disclosure is to provide a battery with improved energy density.

[0005] In some aspects, a battery electrode is provided, characterized by including

[0006] a conductive substrate, on which an active material layer is covered;

[0007] a tab, which extends from the edge of the conductive substrate; and

[0008] a conductive agent layer, which is disposed between the conductive substrate and the active material layer, and the conductive agent layer only covers a part of the area of the active material region, where the active material region refers to the region of the conductive substrate covered by the active material layer;

[0009] wherein, the active material layer and the conductive agent layer are adjacent to the tab, and the conductive agent layer penetrates the active material region.

[0010] The beneficial effects brought about thereby include:

[0011] First, the above-mentioned conductive agent layer only covers a part of the area of the active material region, which helps to reduce the overall weight of the battery electrode without reducing the content of the active material, and thus helps to improve the energy density of the battery electrode;

[0012] Second, the above-mentioned conductive agent layer is adjacent to the tab and establishes an electrical connection with the tab, which can establish a current channel for converging current, and thus can improve the electrical connection between the active material layer and the tab, increase the battery conductivity, reduce the battery internal resistance, and improve the battery rate performance;

[0013] Third, the above-mentioned conductive agent layer penetrates the active material region, which enables the conductive agent layer to pass through the entire active material region, and thus can improve the electrical connection between the whole active material layer and the conductive substrate / tab;

[0014] In summary, by locally covering the conductive agent layer in a specific area of the conductive substrate, the above battery electrode has obtained significantly improved working performance of the battery and increased energy density.

[0015] In some embodiments, the above penetration means that the conductive agent layer extends from one end of the active material area to the other end, dividing the active material area into two or more areas. The penetration can be transverse, longitudinal, or oblique, etc.

[0016] In some embodiments, the battery electrode includes a plurality of conductive agent layers that are distributed at different positions on the conductive substrate and are spaced apart from each other. The plurality of conductive agent layers are respectively adjacent to the tab, and the plurality of conductive agent layers respectively penetrate the active material area.

[0017] Based on this, through the conductive agent layers that are dispersed at different positions and spaced apart from each other, the conductive agent layers can be more widely adjacent to different areas of the active material, improving the electrical connection between the active material layer, the conductive substrate, and the tab. The plurality of conductive agent layers can pass through the entire active material area, and thus can improve the electrical connection between the active material layer and the conductive substrate / tab.

[0018] In some embodiments, the plurality of conductive agent layers are respectively adjacent to different positions of the tab.

[0019] Based on this, it helps to disperse the current outlet end, avoid heat generation caused by over-concentration of current, and improve the heat dissipation performance of the electrode.

[0020] In some embodiments, the edge of the conductive substrate extends out of the first tab and the second tab, there is a gap between the first tab and the second tab, at least one conductive agent layer is adjacent to the first tab, and at least one conductive agent layer is adjacent to the second tab.

[0021] Based on this, it helps to disperse the current outlet end and improve the heat dissipation performance of the electrode.

[0022] In some embodiments, the plurality of conductive agent layers are a plurality of strip-shaped conductive agent layers, and the plurality of strip-shaped conductive agent layers are distributed in a grid pattern.

[0023] Based on this, the strip-shaped conductive agent layers distributed in a grid pattern can be fully adjacent to the active material layer, and thus can improve the electrical connection between the active material layer and the conductive substrate / tab.

[0024] In some embodiments, the conductive agent layer is a strip-shaped conductive agent layer, and the material of the strip-shaped conductive agent layer contains a two-dimensional conductive material. The length direction of the two-dimensional conductive material is parallel to the length direction of the strip-shaped conductive agent layer. The parallel here means substantially parallel, for example, the included angle is 0 to 10°.

[0025] Based on this, the strip-shaped conductive agent layers distributed in a grid pattern have improved conductivity.

[0026] In some embodiments, the conductive agent layer is a strip-shaped conductive agent layer, and the end of the strip-shaped conductive agent abuts against the tab.

[0027] Based on this, a conductive region extending from the strip-shaped conductive agent layer to the tab can be formed, which helps to improve the electrical connection between the active material layer and the tab.

[0028] In some embodiments, the thickness range of the conductive agent layer is (0, 30] μm.

[0029] In some embodiments, the spacing between multiple strip-shaped conductive agent layers is 200 - 1000 mm.

[0030] In some embodiments, there are two strip-shaped conductive agent layers on a conductive substrate.

[0031] In some embodiments, the conductive agent layer abutting against the tab means that the conductive agent layer abuts against the boundary line between the tab and the active material region.

[0032] In some embodiments, the active material layer abutting against the tab means that the active material layer abuts against the boundary line between the tab and the active material region.

[0033] In some embodiments, the conductive substrate is in the form of a foil (with a thickness of, for example, 0.1 - 10000 μm).

[0034] In some embodiments, the battery electrode is in the form of a foil (with a thickness of, for example, 0.1 - 10000 μm).

[0035] In some embodiments, the tab is not covered by the active material layer.

[0036] In some embodiments, the conductive agent layer covers 1 - 99% of the area of the active material region, for example, 10 - 90% of the area, for example, 40 - 60% of the area.

[0037] In some embodiments, the conductive substrate is a rectangular substrate, the rectangular substrate has two long sides, and the conductive agent layer extends from a point on one long side to a point on the other long side.

[0038] In some embodiments, the tab is a full tab.

[0039] In some embodiments, the entire area of the conductive substrate is covered by the active material layer.

[0040] In some embodiments, the conductive substrate is a rectangular conductive substrate, the tab is a strip-shaped tab, and the long side of the strip-shaped tab abuts against the long side of the rectangular conductive substrate.

[0041] In some embodiments, the battery electrode further includes a flame retardant layer disposed between the active material layer and the conductive substrate.

[0042] Based on this, the flame retardant layer can improve the flame retardant performance of the battery electrode and avoid potential safety hazards caused by a large amount of heat release during high-rate operation of the battery.

[0043] In some embodiments, the flame retardant layer contains a flame retardant. For example, the flame retardant is selected from one or more of calcium gluconate, ammonium phosphate, and magnesium aluminum basic carbonate.

[0044] In some embodiments, the flame retardant layer contains dopamine, and the dopamine content is 0.1 - 99.9 wt%.

[0045] In some embodiments, the conductive agent layer contains dopamine. Optionally, the dopamine content is 0.1 - 20%.

[0046] Dopamine has viscosity. Based on this, the viscosity of the conductive agent layer / flame retardant layer can be improved, thereby improving the bonding performance between the active material layer and the conductive substrate and preventing the active material from peeling off the surface of the conductive substrate. In addition, dopamine can improve the flexibility of the conductive agent layer / flame retardant layer, thereby enhancing the overall flexibility of the battery electrode, solving the problem of the battery electrode being fragile after roll pressing, improving the processing performance of the battery electrode, and improving the misalignment problem after the battery is punctured and extruded.

[0047] In some embodiments, the thickness range of the flame retardant layer is (0, 30] μm, such as 1 - 20 μm, 10 - 20 μm, or 20 - 30 μm.

[0048] In some embodiments, the shape of the flame retardant layer is strip-shaped.

[0049] In some embodiments, the shape of the strip-shaped flame retardant layer is a smooth curve strip or a broken line strip.

[0050] In some embodiments, in the broken line strip-shaped flame retardant layer, any included angle on the broken line is less than or equal to 90°.

[0051] In some embodiments, part of the flame retardant layer overlaps with the conductive agent layer, and in the overlapping area, the flame retardant layer is located between the conductive agent layer and the active material layer.

[0052] In some embodiments, the battery electrode is a full tab electrode.

[0053] In some embodiments, the battery electrode is a full-tab electrode, the conductive agent layer includes a plurality of strip-shaped conductive agent layers, the plurality of strip-shaped conductive agent layers are distributed in a grid pattern, and their ends are respectively in contact with different positions on the full tab, and these strip-shaped conductive agent layers are all perpendicular to the full tab.

[0054] In some aspects, a method for preparing the above-mentioned battery electrode is provided, including the following steps:

[0055] 1) A tab is provided at the edge of the conductive substrate and extends from the edge.

[0056] 2) A conductive agent layer is covered on a partial area of the area to be covered with the active material, such that the conductive agent layer is in contact with the tab and penetrates through the area to be covered with the active material. The area to be covered with the active material refers to the area that will be covered by the active material layer.

[0057] 3) An active material layer is covered on the area to be covered with the active material, and the active material layer is in contact with the tab.

[0058] In some embodiments, between steps 2) and 3), there is also a step of drying the conductive agent layer.

[0059] In some embodiments, between steps 2) and 3), there is also a step of coating a flame retardant layer and then drying the flame retardant layer.

[0060] In some aspects, a battery is provided, which contains the battery electrode of any one of the present disclosures. For example, the battery electrode is rolled into a battery core or stacked into a battery core and integrated into a battery casing to obtain a battery.

[0061] In some embodiments, the battery is a lithium-ion secondary battery.

[0062] In some aspects, a battery pack is provided, including a plurality of batteries, and the batteries are the batteries of the present disclosure.

[0063] In some aspects, an electric vehicle is provided, including the battery or the battery pack of the present disclosure.

[0064] In some aspects, an electrical appliance is provided, including the battery or the battery pack of the present disclosure.

[0065] In some embodiments, the conductive substrate refers to a current collector loaded with an active material. The conductive substrate may be a foil-shaped substrate (such as a copper foil or an aluminum foil). The battery active material may be coated on the surface of the current collector in a coating manner to form an active material layer.

[0066] In some embodiments, the tab is a conductive body extending from the conductive substrate without being covered by active material. The tab extends from one side of the conductive substrate, and the shoulder width of the tab is less than or equal to the side length of the conductive substrate on that side. The tab can be used to connect to the battery case and serves as a connection body between the battery cell and the battery case. The number of tabs extending from one side of the conductive substrate can be one or more. For a full-tab structure, the number of tabs extending from one side of the conductive substrate is one, and the shoulder width of the tab is equal to the side length of the conductive substrate on that side.

[0067] In some embodiments, the conductive agent layer is sandwiched between the conductive substrate and the active material layer, which can improve the electrical conductivity between the active material layer and the conductive substrate. The conductive agent is, for example, conductive carbon black, conductive graphite, carbon nanotubes, vapor-grown carbon fiber (VGCF for short), graphene, etc.

[0068] In some embodiments, the conductive agent layer covers the conductive substrate by coating. Specifically, for example, the conductive agent, binder (such as selected from sodium carboxymethyl cellulose, styrene-butadiene rubber, polyvinylidene fluoride) and solvent (such as selected from water, N-methylpyrrolidone) are fully mixed, and the mixture is coated on the conductive substrate. If an aqueous binder system is used, the solvent is water and the binder is sodium carboxymethyl cellulose and styrene-butadiene rubber. If an oil-based binder system is used, the binder is polyvinylidene fluoride and the solvent is N-methylpyrrolidone.

[0069] In some embodiments, the active material refers to an electrical energy storage material that can achieve discharge or charge and discharge through physical or chemical reactions. The active material can be a lithium-ion battery active material, such as a lithium-ion battery positive electrode active material (such as lithium cobaltate, lithium manganate, lithium iron phosphate, ternary materials, etc.), or a lithium-ion battery negative electrode material (such as a carbon-based negative electrode material (such as graphite), a silicon-based negative electrode material, an oxide-based negative electrode material, etc.).

[0070] In some embodiments, the positive electrode active material is selected from one or more of lithium cobaltate, lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum, and lithium manganate. Optionally, the active material layer contains 90-98 parts by weight of active material: 1-2.5 parts by weight of binder: 0.5-5 parts by weight of conductive agent.

[0071] In some embodiments, the active material layer covers the conductive substrate by coating. The active material, binder, conductive agent, and solvent are configured into a slurry, and the solid content of the slurry can be 50%-80%, and then it is coated on the surface of the conductive substrate, and the coating thickness can be 50-200 μm.

[0072] In some embodiments, the flame retardant layer covers the substrate by coating. A slurry is prepared by mixing a flame retardant, polyvinylidene fluoride, and a solvent N-methylpyrrolidone, and then coated on the conductive substrate.

[0073] In some embodiments, starting from the conductive substrate, the conductive agent layer and the active material layer are sequentially arranged from bottom to top.

[0074] In some embodiments, starting from the conductive substrate, the conductive agent layer, the flame retardant layer, and the active material layer are sequentially arranged from bottom to top.

[0075] Term Explanation:

[0076] "Electrical appliances" generally refers to all electrical appliances, which can be household appliances, commercial appliances, industrial appliances, etc.

[0077] "Electric transportation means" generally refers to all transportation means driven by electricity, including both pure electric transportation means and hybrid transportation means, where the transportation means can include vehicles, ships, aircraft, etc.

[0078] In the description of the present disclosure, if the term "bar-shaped" is used, the shape indicated by the above term has a dimension in one dimension that is at least 2 times, such as at least 5 times, or even at least 20 times, the dimensions in the other two dimensions.

[0079] In the present disclosure, "a plurality" means at least 2, such as including but not limited to 3, 4, or 5.

[0080] Beneficial Effects

[0081] One or more of the one or more solutions of the present disclosure have one or more of the following beneficial effects:

[0082] · The battery electrode has improved rate performance;

[0083] · The battery electrode has improved safety performance;

[0084] · The battery electrode has increased energy density.

[0085] The embodiments of the present disclosure will be described in detail below in conjunction with the drawings and examples. However, those skilled in the art will understand that the following drawings and examples are only used to illustrate the present disclosure and not to limit the scope of the present disclosure. According to the following detailed description of the drawings and preferred embodiments, various objects and advantageous aspects of the present disclosure will become apparent to those skilled in the art. Brief Description of the Drawings

[0086] Figure 1 It is a partial schematic diagram of a battery electrode of an embodiment, showing the tab and the conductive substrate in the figure;

[0087] Figure 2 It is a partial schematic diagram of a battery electrode of an embodiment, showing a conductive agent layer in the figure.

[0088] Figure 3 It is a partial schematic diagram of a battery electrode of an embodiment, showing a plurality of conductive agent layers in the figure;

[0089] Figure 4 It is a partial schematic diagram of a battery electrode of an embodiment, showing a plurality of tabs and a plurality of conductive agent layers in the figure;

[0090] Figure 5 It is a partial schematic diagram of a battery electrode of an embodiment, showing a flame retardant layer in the figure;

[0091] Figure 6 It is a top view of a battery electrode of an embodiment, showing the battery electrode covered with an active material layer in the figure. Detailed implementation manners

[0092] The embodiments of the present disclosure will be described in detail below in conjunction with the embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present disclosure and should not be construed as limiting the scope of the present disclosure. For those conditions not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can be obtained as conventional products through commercial purchase.

[0093] The content of the present disclosure and the differences between the present disclosure and the prior art can be understood with reference to the accompanying drawings and the text content below. The technical solutions (including the preferred technical solutions) of the present disclosure will be further described in detail below by way of the accompanying drawings and by listing some optional embodiments of the present disclosure.

[0094] It should be noted that: any technical feature and any technical solution in this embodiment are one or several of a variety of optional technical features or optional technical solutions. For the sake of concise description, it is impossible to enumerate all the alternative technical features and alternative technical solutions of the present disclosure in this document, nor is it convenient to emphasize that each implementation manner of each technical feature is one of the optional multiple implementation manners. Therefore, those skilled in the art should know that any technical means provided by the present disclosure can be replaced or any two or more technical means or technical features provided by the present disclosure can be combined with each other to obtain a new technical solution.

[0095] Figure 1 It is a partial schematic diagram of a battery electrode of an embodiment, showing tab 1 and conductive substrate 2 in the figure. The conductive substrate 2 is a rectangular substrate. Tab 1 extends from one long side of the conductive substrate 2. The tab 1 is a full tab, and its shoulder width is equal to the side length of the long side of the above-mentioned conductive substrate 2. The shape of the tab 1 is strip-shaped, and the long side direction of the tab 1 is parallel to the long side direction of the conductive substrate 2.

[0096] Figure 6 is a top view of a battery electrode of an embodiment, in which an active material layer 5 is shown covering a conductive substrate 2. In this embodiment, the active material layer 5 covers the entire area of the conductive substrate 2, and the active material layer 5 abuts against the tab 1, and the tab 1 is not covered by the active material layer 5. The area covered by the active material layer 5 is the active material region 21.

[0097] Figure 2 is a partial schematic view of a battery electrode of an embodiment. A conductive agent layer 3 is disposed between the conductive substrate 2 and the active material layer 5. In order to show the conductive agent layer 3 located between the active material layer 5 and the conductive substrate 2, Figure 2 the active material layer 5 covering the conductive substrate 2 is not shown in the figure. As Figure 2 shown, the conductive agent layer 3 only covers a part of the active material region 21. The conductive substrate 2 is a rectangular substrate, and the rectangular substrate has two long sides. The conductive agent layer 3 extends from a point on one long side to a point on the other long side, passing through the active material region 21. The end of the conductive agent layer 3 abuts against the tab 1, which helps to conduct the current out to the tab. The conductive agent layer 3 passes through the active material region 21, which helps to extend deep into the active material region 21, and thus can improve the electrical connection between the active material layer 5 and the tab 1.

[0098] Figure 3 is a partial schematic view of a battery electrode of an embodiment, in which a plurality of conductive agent layers (3a, 3b, 3c) are shown. Each conductive agent layer (3a, 3b, 3c) abuts against the tab 1 respectively and passes through the active material region 21. The plurality of conductive agent layers help to further improve the electrical connection between the active material layer and the conductive substrate 2 and the tab 1. In addition, the plurality of conductive agent layers (3a, 3b, 3c) are distributed and abut against different positions of the tab 1, which helps to disperse the current output end and avoid excessive local current.

[0099] Figure 4 is a partial schematic view of a battery electrode of an embodiment, in which a plurality of tabs (1a, 1b, 1c) and a plurality of conductive agent layers (3a, 3b, 3c) are shown. The conductive agent layer 3a abuts against the tab 1a, the conductive agent layer 3b abuts against the tab 1b, and the conductive agent layer 3c abuts against the tab 1c. Each conductive agent layer (3a, 3b, 3c) passes through the active material region 21. The plurality of conductive agent layers (3a, 3b, 3c) are distributed and abut against different tabs, which helps to disperse the current output end and avoid excessive local current.

[0100] Figure 5It is a partial schematic diagram of a battery electrode of an embodiment, in which a flame retardant layer 4 is shown. The flame retardant layer 4 is disposed between the active material layer 5 and the conductive substrate 2. Part of the flame retardant layer 4 overlaps with the conductive agent layer 3, and in the overlapping area, the flame retardant layer 4 is located between the conductive agent layer 3 and the active material layer 5. The flame retardant layer 4 only covers a partial area of the active material region 21. The shape of the flame retardant layer 4 is a broken line strip. The angle of the broken line is less than 90°. The flame retardant layer contains a flame retardant, which can improve the safety performance of the battery electrode. The fact that the flame retardant layer only covers a partial area of the active material region helps to reduce the overall weight of the battery.

[0101] In some embodiments, the shape of the flame retardant layer 4 can also be a smooth curve strip, and can also be other types of continuous strip coating layers.

[0102] In some embodiments, the flame retardant layer 4 contains dopamine, which improves the viscosity of the flame retardant 4, helps to improve the bonding performance between the active material layer 5 and the conductive substrate 2; and helps to improve the flexibility of the battery electrode.

[0103] For any of the technical solutions disclosed in the present disclosure, unless otherwise stated, if it discloses a numerical range, the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is only the numerical values with obvious technical effects or representativeness among many implementable numerical values. Since there are too many numerical values to enumerate, the present disclosure only discloses some numerical values to illustrate the technical solutions of the present disclosure, and the above-listed numerical values should not constitute a limitation on the protection scope of the present disclosure.

[0104] In addition, for any of the technical solutions disclosed in the present disclosure, the terms used to represent the positional relationship or shape, unless otherwise stated, include states or shapes that are approximate, similar, or close to them. Any component provided by the present disclosure can either be assembled from multiple individual components or be a single component manufactured by an integral forming process.

[0105] If terms such as "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are used in the description of the present disclosure, the orientation or positional relationship indicated by the above terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device, mechanism, component, or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection scope of the present disclosure.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure and are not intended to limit them. Although the present disclosure has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that modifications can still be made to the specific implementation manners of the present disclosure or equivalent replacements can be made to some technical features. Without departing from the spirit of the technical solutions of the present disclosure, they should all be covered within the scope of the technical solutions claimed by the present disclosure.

Claims

1. A battery electrode, characterized in that, including a conductive substrate, on which an active material layer is covered; tab ears, which extend from the edge of the conductive substrate; and a conductive agent layer, which is disposed between the conductive substrate and the active material layer, and the conductive agent layer only covers a partial area of the active material region, where the active material region refers to the region of the conductive substrate covered by the active material layer; wherein, the active material layer and the conductive agent layer are in contact with the tab ears, and the conductive agent layer penetrates through the active material region; the conductive agent layer is a strip-shaped conductive agent layer, and the material of the strip-shaped conductive agent layer contains a two-dimensional conductive material, and the length direction of the two-dimensional conductive material is parallel to the length direction of the strip-shaped conductive agent layer.

2. The battery electrode according to claim 1, wherein The battery electrode includes a plurality of conductive agent layers distributed at different positions on the conductive substrate and spaced apart from each other, and the plurality of conductive agent layers are respectively in contact with the tab ears and respectively penetrate through the active material region.

3. The battery electrode according to claim 2, wherein The plurality of conductive agent layers are respectively in contact with different positions of the tab ears.

4. The battery electrode according to claim 2, characterized in that, First tab ear and second tab ear extend from the edge of the conductive substrate, there is a gap between the first tab ear and the second tab ear, at least one conductive agent layer is in contact with the first tab ear, and at least one conductive agent layer is in contact with the second tab ear.

5. The battery electrode according to claim 2, wherein, The plurality of conductive agent layers are a plurality of strip-shaped conductive agent layers, and the plurality of strip-shaped conductive agent layers are distributed in a grid shape.

6. The battery electrode according to claim 1, wherein The conductive agent layer is a strip-shaped conductive agent layer, and the end of the strip-shaped conductive agent is in contact with the tab ear.

7. The battery electrode according to claim 1, wherein One or more of the following: - The conductive substrate is in the form of a foil; - The battery electrode is in the form of a foil; - The conductive agent layer covers 1 to 99% of the area of the active material region; - The entire region of the conductive substrate is covered by the active material layer; - The conductive agent layer contains dopamine; - The tab ear is a full tab ear; - The tab ear is not covered by the active material layer; - The conductive agent layer being in contact with the tab ear means that the conductive agent layer is in contact with the boundary line between the tab ear and the active material region; - The active material layer being in contact with the tab ear means that the active material layer is in contact with the boundary line between the tab ear and the active material region; - The conductive substrate is a rectangular substrate, the rectangular substrate has two long sides, and the conductive agent layer extends from a point on one long side to a point on the other long side.

8. The battery electrode according to claim 1, wherein, The battery electrode further includes a flame retardant layer, and is disposed between the active material layer and the conductive substrate.

9. The battery electrode according to claim 8, wherein One or more of the following: - The flame retardant layer only covers a partial area of the active material region; - The shape of the flame retardant layer is strip-shaped; - Part of the flame retardant layer overlaps with the conductive agent layer, and in the overlapping region, the flame retardant layer is located between the conductive agent layer and the active material layer; - The flame retardant layer contains dopamine; 10. The battery electrode according to claim 8, characterized in that, The shape of the flame retardant layer is a smooth curve strip or a broken line strip.

11. A method for preparing the battery electrode according to any one of claims 1 to 10, characterized in that, Including the following steps: 1) Set tab ears extending from the edge at the edge of the conductive substrate; 2) Cover a conductive agent layer on a partial area of the to-be-covered active material region, so that the conductive agent layer is in contact with the tab ear and penetrates through the to-be-covered active material region, where the to-be-covered active material region refers to the region to be covered by the active material layer; 3) Cover an active material layer on the to-be-covered active material region, and the active material layer is in contact with the tab ear.

12. The method according to claim 11, wherein, A step of drying the conductive agent layer is further included between steps 2) and 3).

13. The method according to claim 11, wherein, Between step 2) and step 3), there is also a step of coating a flame retardant layer and then drying the flame retardant layer.

14. A battery, characterized in that, Containing the battery electrode according to any one of claims 1 to 10.

15. The battery according to claim 14, wherein The battery is a lithium ion secondary battery.

16. A battery pack, characterized in that, Comprising a plurality of batteries, the battery being the battery according to any one of claims 14 or 15.

17. An electric vehicle, characterized in that, Comprising the battery according to any one of claims 14 or 15 or the battery pack according to claim 16.

18. An electrical appliance, characterized in that, Comprising the battery according to any one of claims 14 or 15 or the battery pack according to claim 16.

Images