Pole piece and battery cell

Abstract

The utility model discloses a pole piece and a battery cell, the pole piece comprises: an insulation substrate layer, which is a porous structure, is provided with a plurality of first through holes, and comprises a tab connection area and an active material support area; the conductive piece is arranged in the first through hole; the metal layer is connected to the tab connecting area, and the conductive piece is electrically connected with the metal layer; and the active material layer is connected to the active material supporting region. The pole piece disclosed by the utility model can have relatively high energy density.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to an electrode and a battery cell. Background Technology

[0002] In related technologies, the electrode includes a current collector and an active material layer. The current collector includes composite current collectors, which generally consist of a non-conductive polymer middle layer and a surface metal conductor. The non-conductive polymer provides structural support; the metal conductor provides electrons to the electrode active material and connects to the tabs, thus performing the functions of conductivity, current collection, and current flow in the tab area. Adding two metal layers on each side of the middle layer results in a smaller amount of active material that the electrode can accommodate, leading to a lower energy density. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an electrode that can have a high energy density.

[0004] This utility model also proposes a battery cell.

[0005] The electrode sheet according to a first aspect embodiment of the present invention includes:

[0006] An insulating substrate layer has a porous structure and has multiple first through-holes. The insulating substrate layer includes a tab connection region and an active material support region.

[0007] A conductive element is disposed in the first through hole;

[0008] A metal layer is connected to the tab connection area, and the conductive element is electrically connected to the metal layer;

[0009] An active material layer is connected to the active material support region.

[0010] The electrode sheet according to the embodiments of this utility model has at least the following beneficial effects: the insulating substrate layer has a porous structure, the conductive element is disposed in the first through hole, the insulating substrate layer includes a tab connection region and an active material support region, and the active material layer is connected to the active material support region. In the prior art, a metal layer is disposed on both the tab connection region and the active material support region of the insulating substrate layer, and then the active material layer is disposed on the metal layer. In this application, the metal layer on the active material support region is omitted, and the active material layer can be directly disposed on the active material support region. Therefore, compared with the prior art, more active material layers can be disposed on the active material support region, thereby improving the energy density of the electrode sheet. Specifically, the electrode sheet can have a higher energy density.

[0011] According to some embodiments of the present invention, the conductive element and the wall of the first through hole together define a second through hole, and the porosity of the second through hole is A, 5%≤A≤60%.

[0012] According to some embodiments of the present invention, a portion of the active material layer is disposed in the second through hole.

[0013] According to some embodiments of the present invention, the diameter of the first through hole is B, where 20nm≤B≤6000nm.

[0014] According to some embodiments of the present invention, the electrode sheet includes a first sub-active material layer and a second sub-active material layer. The two sides of the first sub-active material layer are respectively connected to the active material support region and the second sub-active material layer. The particle size of the first sub-active material layer is smaller than that of the second sub-active material layer.

[0015] According to some embodiments of the present invention, the active material layer covers a portion of the metal layer in the electrode sheet.

[0016] According to some embodiments of the present invention, the electrode sheet has an area C along the length of the insulating substrate layer, where the active material layer covers the metal layer, and C ≤ 10 mm.

[0017] The battery cell according to the second aspect embodiment of the present invention includes the electrode sheet as described in any one of the first aspect embodiments.

[0018] The battery cell according to the embodiments of this utility model has at least the following beneficial effects: the insulating base layer has a porous structure, the conductive element is disposed in the first through hole, the insulating base layer includes a tab connection region and an active material support region, and the active material layer is connected to the active material support region. In the prior art, a metal layer is disposed on both the tab connection region and the active material support region of the insulating base layer, and then the active material layer is disposed on the metal layer. In this application, the metal layer on the active material support region is omitted, and the active material layer can be directly disposed on the active material support region. Therefore, compared with the prior art, more active material layers can be disposed on the active material support region, thereby improving the energy density of the electrode. Specifically, the electrode can have a higher energy density. Furthermore, the battery cell with this electrode also has a higher energy density.

[0019] According to some embodiments of the present invention, the battery cell further includes tabs that are electrically connected to the metal layer.

[0020] According to some embodiments of the present invention, the size of the electrode tab is L1 along the length direction of the electrode sheet, and the size of the metal layer is L2, where L1 < L2 < 6L1.

[0021] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0023] Figure 1 This is a schematic diagram of the electrode sheet according to the first embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the electrode sheet according to the second embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the electrode sheet according to the third embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of a battery cell according to some embodiments of the present invention.

[0027] Figure label:

[0028] Electrode 10, insulating substrate 100, first through hole 110, electrode connection area 120, active material support area 130, second through hole 140, conductive element 200, metal layer 300, active material layer 400, first sub-active material layer 410, second sub-active material layer 420, battery cell 500, electrode 600. Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0030] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, 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. Therefore, they should not be construed as limitations on this utility model.

[0031] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0032] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0033] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0034] The battery can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0035] A battery typically consists of a cell. The cell includes a positive electrode, a negative electrode, and a separator. During charging and discharging, active ions (such as lithium ions) move back and forth between the positive and negative electrodes, inserting and releasing. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0036] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0037] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0038] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0039] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0040] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0041] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0042] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0043] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0044] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0045] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in batteries. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0046] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0047] In some implementations, the battery cell also includes an isolation element disposed between the positive and negative terminals.

[0048] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0049] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0050] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0051] In some embodiments, the battery also includes an electrolyte that acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0052] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0053] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0054] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0055] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0056] As an example, polymer solid electrolytes can be polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0057] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0058] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0059] In some implementations, the battery cell has a wound structure. The positive and negative electrode plates are wound into a wound structure.

[0060] In some implementations, the battery cell has a laminated structure.

[0061] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0062] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0063] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0064] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0065] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0066] In some implementations, the battery cell can be cylindrical, flat, or polygonal, etc.

[0067] In some implementations, the battery cell is provided with tabs that allow current to be drawn out of the cell. The tabs include a positive tab and a negative tab.

[0068] In some embodiments, the battery may include a casing. The casing is used to encapsulate components such as the battery cell and electrolyte. The casing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0069] As an example, the battery can be a cylindrical battery, a prismatic battery, a pouch battery, or a battery of other shapes. Prismatic batteries include, but are not limited to, square-shell batteries, blade-shaped batteries, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0070] The battery mentioned in the embodiments of this application refers to a single physical module that includes one or more batteries to provide higher voltage and capacity.

[0071] In some embodiments, the battery can be a battery module, and when there are multiple batteries, the multiple batteries are arranged and fixed to form a battery module.

[0072] In some embodiments, the battery may be a battery pack, which includes a housing and a battery, with the battery or battery module housed within the housing.

[0073] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0074] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0075] In related technologies, an electrode includes a current collector and an active material layer. The current collector includes composite current collectors, which generally consist of a non-conductive polymer middle layer and a surface metal conductor. The non-conductive polymer provides structural support; the metal conductor provides electrons to the electrode active material and connects to the tabs, thus performing conductivity, current collection, and current flow control in the tab region. However, adding two metal layers on either side of the middle layer results in a smaller amount of active material that the electrode can accommodate, leading to a lower energy density. Therefore, this application proposes an electrode.

[0076] Please refer to Figures 1 to 3 ,in, Figure 1 The diagram illustrates the first through hole 110, which does not contain a conductive element 200. Figure 2 The diagram illustrates the case where the conductive element 200 forms a second through hole 140 in the first through hole 110. Figure 3The diagram illustrates the conductive element 200 within the insulating substrate 100. In some embodiments, the electrode 10 includes: an insulating substrate 100, a conductive element 200, a metal layer 300, and an active material layer 400. The electrode 10 can be a positive or negative electrode, primarily determined by the material of the active material layer 400; this is prior art and will not be elaborated further here. The insulating substrate 100 has a porous structure. The insulating substrate 100 is made of an insulating material, such as PP, PE, or PET. The porous structure of the insulating substrate 100 specifically means that it has multiple first through holes 110, which are interconnected. The insulating substrate 100 includes a tab 600 connection region 120 and an active material support region 130 along its length. The tab 600 connection region 120 is used to connect the metal layer 300, thereby connecting it to the tab 600.

[0077] The conductive element 200 is disposed in the first through hole 110. The conductive element 200 can be an sp-type conductive carbon black material with a particle size of 10nm~60nm; or, the conductive element 200 can be a CNT-type material with a tube length of 5um~40um; or, the conductive element 200 can be a planar graphene conductive agent.

[0078] Metal layer 300 is connected to connection area 120 of tab 600, and conductive element 200 is electrically connected to metal layer 300. The material of metal layer 300 can be gold, silver, copper, aluminum, etc., and is not specifically limited here. The thickness of metal layer 300 can be 0.5µm to 5µm. Active material layer 400 is connected to active material support area 130.

[0079] Specifically, the insulating substrate 100 has a porous structure, and the conductive element 200 is disposed in the first through hole 110. The insulating substrate 100 includes a tab 600 connection region 120 and an active material support region 130. The active material layer 400 is connected to the active material support region 130. In the prior art, both the tab 600 connection region 120 and the active material support region 130 of the insulating substrate 100 are provided with a metal layer 300, and then the active material layer 400 is disposed on the metal layer 300. In this application, the metal layer 300 is omitted from the active material support region 130, and the active material layer 400 can be directly disposed on the active material support region 130. Therefore, compared with the prior art, more active material layers 400 can be disposed on the active material support region 130, thereby improving the energy density of the electrode 10. Specifically, the electrode 10 can have a higher energy density. Furthermore, after the electrode 10 is made into a battery, it can also improve the rate performance and battery life of the battery.

[0080] Furthermore, the active material layer 400 can be connected to the active material support region 130 by coating the active material onto the active material support region 130, thereby forming the active material layer 400. The conductive element 200 can be a conductive material. After the conductive element 200 is disposed in the first through-hole 110, the current generated by the chemical reaction of the active material layer 400 can be transmitted to the metal layer 300 through the conductive element 200. The metal layer 300 and the tab 600 are electrically connected, thereby conducting the current of the electrode 10 to the outside world. The shape of the conductive element 200 is not specifically limited; for example, the conductive element 200 can be granular, tubular, wire-like, or other shapes. Multiple conductive elements 200 can be present. After multiple conductive elements 200 are disposed in the first through-hole 110, the multiple conductive elements 200 are interconnected, thereby realizing the transmission of current. Specifically, the surface of the active material support region 130 is coated with an active material layer 400, which is connected to the conductive element 200 in the porous insulating substrate layer 100, further increasing the conductive network and thus improving the rate performance.

[0081] Further, please refer to Figures 1 to 3 In some embodiments, the conductive element 200 and the wall of the first through-hole 110 together define a second through-hole 140, the porosity of the second through-hole 140 being A, where 5% ≤ A ≤ 60%. Specifically, the insulating substrate layer 100 has a porous structure, wherein the porosity of the insulating substrate layer 100 is 20%~70%, and the conductive element 200 is disposed in the first through-hole 110, thereby filling the first through-hole 110. The volume of the conductive element 200 is smaller than the volume of the first through-hole 110, so after the conductive element 200 is disposed in the first through-hole 110, the conductive element 200 and the wall of the first through-hole 110 together define the second through-hole 140, which can be used to accommodate the active material layer 400, thereby increasing the energy density of the electrode 10. The porosity of the second through-hole 140 can be 5%, 10%, 20%, 30%, or 60%. When the porosity of the second through-hole 140 is less than 5%, the porosity is too small, which results in a limited amount of active material that can be accommodated, leading to a small increase in the energy density of the electrode 10. When the porosity of the second through-hole 140 is greater than 60%, the amount of conductive element 200 is too small, which results in poor current transmission efficiency.

[0082] Specifically, the performance comparison between the electrode 10 of this application and the electrode 10 in the prior art can be referred to in the table below.

[0083]

[0084] As can be seen from the table above, Example 1 is a conventional electrode 10, with a metal layer 300 and an active material layer 400 disposed on both sides of the insulating substrate layer 100. Compared with the electrode 10 in this application, the electrode 10 in this application has a higher energy density.

[0085] Further, please refer to Figures 1 to 3 In some embodiments, a portion of the active material layer 400 is disposed within the second through-hole 140. Specifically, since the metal component is disposed within the first through-hole 110, it does not completely fill the first through-hole 110, thus forming the second through-hole 140. A portion of the active material layer 400 can be disposed within the second through-hole 140, thereby filling the second through-hole 140. That is, a portion of the active material layer 400 is disposed within the second through-hole 140, which can effectively improve the energy density of the electrode 10. Furthermore, the second through-hole 140 can also accommodate electrolyte, improving electrolyte retention capacity and thus extending battery life.

[0086] Further, please refer to Figures 1 to 3 In some embodiments, the aperture of the first through-hole 110 is B, where 20nm ≤ B ≤ 6000nm. Specifically, the aperture of the first through-hole 110 can be 20nm, 50nm, 100nm, 1000nm, 3000nm, 4000nm, 5000nm, 5500nm, or 6000nm. When the aperture of the first through-hole 110 is less than 20nm, the small aperture requires a smaller metal component, increasing processing difficulty and resulting in higher manufacturing costs for the electrode 10. When the aperture of the first through-hole 110 is greater than 6000nm, the excessively large aperture leads to lower structural strength of the insulating substrate layer 100.

[0087] Further, please refer to Figures 1 to 3 In some embodiments, the active material layer 400 includes a first sub-active material layer 410 and a second sub-active material layer 420. The first sub-active material layer 410 is connected to the active material support region 130 and the second sub-active material layer 420 on both sides, respectively. The particle size of the first sub-active material layer 410 is smaller than that of the second sub-active material layer 420. Specifically, this configuration can improve the rate performance of the electrode 10, thereby improving the performance of the electrode 10. It should be noted that there can be two active material layers 400, located on opposite sides of the insulating substrate layer 100 in the thickness direction. The first sub-active material layer 410 can be made of small-particle-size graphite, hard carbon, or soft carbon, possessing a lithium intercalation structure and good conductivity, with a particle size of 0.6 μm < D10 < 8 μm. The second sub-active material layer 420 can be made of a conventionally sized lithium intercalation active material.

[0088] Further, please refer to Figure 2In some embodiments, the active material layer 400 covers a portion of the metal layer 300. Specifically, the active material layer 400 can cover the entire active material support region 130. In some cases, the active material layer 400 can also cover a portion of the metal layer 300. This will not affect the connection between the metal layer 300 and the tab 600, while reducing the processing difficulty and improving the efficiency of placing the active material layer 400 on the insulating substrate layer 100.

[0089] Further, please refer to Figure 2 In some embodiments, along the length of the insulating substrate 100, the active material layer 400 covers the metal layer 300 by a dimension C, where C ≤ 10 mm. Specifically, the dimension of the active material layer 400 covering the metal layer 300 can be 1 mm, 2 mm, 3 mm, 5 mm, 6 mm, 8 mm, 9 mm, or 10 mm. When the dimension of the active material layer 400 covering the metal layer 300 is greater than 10 mm, the exposed area of ​​the metal layer 300 becomes too small, making it inconvenient to solder with the tab 600.

[0090] Please refer to Figure 4 In some embodiments, the battery cell 500 includes the electrode 10 of any of the above embodiments. Specifically, the insulating substrate 100 has a porous structure, the conductive element 200 is disposed in the first through hole 110, the insulating substrate 100 includes a tab 600 connection region 120 and an active material support region 130, and the active material layer 400 is connected to the active material support region 130. In the prior art, a metal layer 300 is disposed on both the tab 600 connection region 120 and the active material support region 130 of the insulating substrate 100, and then the active material layer 400 is disposed on the metal layer 300. In this application, the metal layer 300 is omitted on the active material support region 130, and the active material layer 400 can be directly disposed on the active material support region 130. Therefore, compared with the prior art, more active material layers 400 can be disposed on the active material support region 130, thereby improving the energy density of the electrode 10. Specifically, the electrode 10 can have a higher energy density. Furthermore, the cell 500 with this electrode 10 also has a higher energy density.

[0091] Further, please refer to Figure 4In some embodiments, the battery cell 500 further includes a tab 600, which is electrically connected to the metal layer 300. Specifically, the tab 600 can be connected to the metal layer 300 by welding. There can be one metal layer 300 located on one side of the insulating substrate 100 in the thickness direction, or there can be two metal layers 300 located on opposite sides of the insulating substrate 100 in the thickness direction. After the tab 600 is electrically connected to the metal layer 300, it can conduct the current of the electrode 10 to the outside environment.

[0092] Further, please refer to Figure 4 In some embodiments, along the length of the electrode 10, the tab 600 has a size of L1, and the metal layer 300 has a size of L2, where L1 < L2 < 6L1. Specifically, along the length of the electrode 10, the size of the tab 600 can be the same as the size of the metal layer 300. This ensures that the tab 600 has sufficient space to connect with the metal layer 300, and the connection between the tab 600 and the metal layer 300 has high stability. The maximum size of the metal layer 300 can be six times that of the tab 600. If the size of the metal layer 300 continues to increase, it will lead to a smaller size of the active material support region 130, a smaller amount of active material accommodated on the electrode 10, and a lower energy density of the cell 500.

[0093] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A pole piece characterized by, The application relates to a positive electrode plate, which comprises: an insulating base layer with a porous structure, the insulating base layer having a plurality of first through holes, the insulating base layer comprising a tab connecting area and an active material supporting area; a conductive piece arranged in the first through hole; a metal layer connected to the tab connecting area, the conductive piece being electrically connected to the metal layer; an active material layer connected to the active material supporting area.

2. The pole piece of claim 1, wherein The conductive piece and the hole wall of the first through hole jointly define a second through hole, the porosity of the second through hole being A, 5%<=A<=60%.

3. The pole piece of claim 2, wherein Part of the active material layer is arranged in the second through hole.

4. The pole piece of claim 1, wherein The hole diameter of the first through hole is B, 20nm<=B<=6000nm.

5. The pole piece of claim 1, wherein The active material layer comprises a first sub-active material layer and a second sub-active material layer, the two sides of the first sub-active material layer being connected to the active material supporting area and the second sub-active material layer respectively, the particle size of the first sub-active material layer being smaller than that of the second sub-active material layer.

6. The pole piece of claim 1, wherein The active material layer covers part of the metal layer.

7. The pole piece of claim 6, wherein In the length direction of the insulating base layer, the size of the active material layer covering the metal layer is C, C<=10mm.

8. An electric cell, characterized by The application further relates to a positive electrode plate comprising the positive electrode plate as claimed in any one of claims 1 to 7.

9. The electric cell of claim 8, wherein, The battery cell further comprises a tab, the tab being electrically connected to the metal layer.

10. The electric cell of claim 8, wherein, In the length direction of the positive electrode plate, the size of the tab is L1, the size of the metal layer is L2, L1

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