Cathode pole piece, battery and electric device

Abstract

The utility model belongs to the technical field of battery production and manufacturing, and particularly relates to a cathode pole piece which comprises a current collector, the current collector is a metal layer, the upper surface and the lower surface of the metal layer are coated with active material layers, and the thickness of the metal layer is not larger than 10 micrometers. Wherein an improved coating is arranged between the metal layer and the active material layer, and the upper surface and the lower surface of the metal layer are coated with the improved coating. According to the utility model, the improved coating is arranged, so that the problem that the current collector of the cathode pole piece is easy to break during rolling can be improved. In addition, the utility model also discloses a battery comprising the cathode pole piece and an electric device.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery production and manufacturing, and specifically relates to a cathode electrode piece, a battery and an electrical device. Background Art

[0002] Nowadays, with the development of modern society and the enhancement of people's environmental awareness, more and more devices choose lithium-ion batteries as power sources, such as mobile phones, laptops, power tools and electric vehicles, which provides a broad space for the application and development of lithium-ion batteries.

[0003] In the process of manufacturing multi-electrode winding cells, the cathode current collector with a thickness of less than 10 microns is not as tough as the anode current collector due to its own material problems, and contains a large number of pores, impurities and other defects, which will cause uneven stretching force during rolling, resulting in easy breakage of the current collector. Therefore, it is urgent to propose a new technical solution to solve the above problems. Utility Model Content

[0004] One of the purposes of the present utility model is to address the deficiencies of the prior art and provide a cathode electrode sheet, which increases the adhesion between the active material layer and the current collector by setting an improved coating between the current collector and the active material layer, thereby improving the problem that the cathode electrode sheet is easily broken during rolling.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A cathode electrode sheet comprises a current collector, wherein the current collector is a metal layer, and the upper and lower surfaces of the metal layer are coated with active material layers, and the thickness of the metal layer is not greater than 10 μm; wherein an improved coating is arranged between the metal layer and the active material layer, and the improved coating is coated on the upper and lower surfaces of the metal layer.

[0007] As an improvement of the cathode electrode plate described in the utility model, the coating area of ​​the improved coating is the same as the area of ​​the metal layer, that is, the improved coating covers the entire metal layer, which can maximize the bearing capacity of the cathode electrode plate.

[0008] As an improvement of the cathode electrode piece described in the utility model, the thickness of the improved coating is 100nm-500nm, and the thickness of the improved coating is thin enough and will not affect the performance of the cathode electrode piece.

[0009] As an improvement of the cathode electrode plate described in the utility model, the improved coating has a substrate layer, and the substrate layer is one of oxide functional materials such as aluminum oxide, zirconium oxide, titanium oxide, chromium oxide, cobalt oxide, vanadium oxide, iron oxide, manganese oxide, magnesium oxide, barium oxide, rubidium oxide, cesium oxide, bismuth oxide, germanium oxide, tantalum oxide, yttrium oxide, molybdenum oxide, rhenium oxide, and tungsten oxide.

[0010] As an improvement of the cathode electrode sheet described in the utility model, the improved coating contains a sodium chloride layer or a potassium chloride layer, and the thickness ratio of the improved coating to the thickness of the sodium chloride layer or the potassium chloride layer is 1:0.05-0.1. The provision of the sodium chloride layer or the potassium chloride layer can improve the thermal conductivity and fluidity of the current collector, making the welding more stable, and at the same time can also reduce the pores in the welding process of the current collector and improve the strength and sealing of the weld.

[0011] As an improvement of the cathode electrode plate described in the utility model, the cathode electrode plate also includes an empty foil area, which is a current collector not coated with the active material layer, and the empty foil area and the active material layer are alternately arranged along the surface of the improved coating.

[0012] As an improvement of the cathode electrode sheet described in the utility model, the empty foil area is arranged on both sides of the metal layer, and the empty foil areas on both sides are arranged correspondingly.

[0013] As an improvement of the cathode electrode sheet described in the utility model, the empty foil area is provided with the improved coating, and the improved coating can fill the defects and pores on the surface of the empty foil area.

[0014] As an improvement of the cathode electrode plate described in the utility model, the thickness of the metal layer is 8 μm to 10 μm.

[0015] The second purpose of the utility model is to provide a battery, comprising the cathode electrode sheet as described above.

[0016] The third object of the present utility model is to provide an electrical device comprising the battery as described above.

[0017] The beneficial effect of the utility model is that the cathode electrode sheet of the utility model includes a current collector, the current collector is a metal layer, the upper and lower surfaces of the metal layer are coated with active material layers, and the thickness of the metal layer is not more than 10 μm; wherein an improved coating is provided between the metal layer and the active material layer, and the improved coating is coated on the upper and lower surfaces of the metal layer. The utility model increases the adsorption force between the metal layer and the active material layer by providing an improved coating between the metal layer and the active material layer, thereby preventing the current collector with a thickness of less than 10 μm from breaking during the rolling process, thereby increasing its safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The features, advantages and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

[0019] Figure 1 It is a structural schematic diagram of the utility model.

[0020] The reference numerals are described as follows:

[0021] 1-Metal layer;

[0022] 2-active material layer;

[0023] 3- Improve coating;

[0024] 4- Empty foil area. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0027] Reference to "embodiment" in this application means that a particular feature, structure or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0028] In the embodiments of the present application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0029] The term "plurality" used in the present application refers to two or more (including two).

[0030] In the present application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries or magnesium-ion batteries, etc., and the embodiments of the present application do not limit this. Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0031] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a cathode sheet, an anode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the cathode sheet and the anode sheet to work. The cathode sheet includes a cathode current collector and a cathode active material layer. The cathode active material layer is coated on the surface of the cathode current collector. The cathode current collector not coated with the cathode active material layer protrudes from the cathode current collector coated with the cathode active material layer. The cathode current collector not coated with the cathode active material layer serves as the cathode tab. Taking lithium-ion batteries as an example, the material of the cathode current collector may be aluminum, and the cathode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The anode sheet includes an anode current collector and an anode active material layer. The anode active material layer is coated on the surface of the anode current collector. The anode current collector not coated with the anode active material layer protrudes from the anode current collector coated with the anode active material layer. The anode current collector not coated with the anode active material layer serves as the anode tab. The material of the anode current collector may be copper, and the anode active material may be carbon or silicon, etc. In order to ensure that a large current does not melt, the cathode tabs are multiple and stacked together, and the anode tabs are multiple and stacked together. The material of the isolation film can be PP (polypropylene) or PE (polyethylene).

[0032] The inventors found that during the winding process of the battery, the cathode current collector with a thickness of less than 10 microns is prone to breakage. In view of this, the embodiment of the present application provides a technical solution to improve the above problem by providing an improved coating.

[0033] The following is combined with Figure 1 The utility model is further described in detail with specific implementation modes, but is not intended to limit the utility model.

[0034] Implementation Method 1

[0035] like Figure 1 As shown, a cathode electrode sheet includes a current collector, the current collector is a metal layer 1, the upper and lower surfaces of the metal layer 1 are coated with an active material layer 2, and the thickness of the metal layer 1 is not more than 10μm; wherein, an improved coating 3 is arranged between the metal layer 1 and the active material layer 2, and the improved coating 3 is coated on both sides of the metal layer 1.

[0036] Preferably, the coating area of ​​the improved coating 3 is the same as the area of ​​the metal layer 1 , that is, the improved coating 3 covers the entire metal layer 1 , which can maximize the bearing capacity of the cathode electrode.

[0037] Preferably, the thickness of the improved coating 3 is 100nm-200nm, 200nm-300nm, 300nm-400nm, 400nm-500nm. The thickness of the improved coating 3 is small enough to avoid affecting the thickness of the cathode electrode and thus affecting the battery performance.

[0038] Preferably, the thickness of the metal layer 1 is 8 μm to 10 μm.

[0039] Preferably, the improved coating 3 has a substrate layer, and the substrate layer is one of oxide functional materials such as aluminum oxide, zirconium oxide, titanium oxide, chromium oxide, cobalt oxide, vanadium oxide, iron oxide, manganese oxide, magnesium oxide, barium oxide, rubidium oxide, cesium oxide, bismuth oxide, germanium oxide, tantalum oxide, yttrium oxide, molybdenum oxide, rhenium oxide, and tungsten oxide. The improved coating 3 can increase the adsorption force of the metal layer 1 and the active material layer 2, thereby increasing the bearing capacity of the cathode electrode and avoiding the metal layer 1 from breaking during rolling.

[0040] Preferably, the cathode electrode sheet also includes a plurality of empty foil areas 4, the empty foil areas 4 being areas of the metal layer 1 and the improved coating 3 that are not coated with the active material layer 2, the empty foil areas 4 and the active material layer 2 being alternately arranged along the surface of the improved coating 3, the empty foil areas 4 being arranged on both sides of the metal layer 1, the empty foil areas 4 on both sides being arranged correspondingly, the empty foil areas 4 being all provided with the improved coating 3, the improved coating 3 coated on the empty foil areas 4 being able to fill the defects and pores on the surface of the empty foil areas 4, further preventing the metal layer 1 from breaking during rolling.

[0041] Implementation Method 2

[0042] Different from the first embodiment, the improved coating 3 in this embodiment contains a sodium chloride layer or a potassium chloride layer, and the thickness ratio of the improved coating 3 to the sodium chloride layer or the potassium chloride layer is 1:0.05-0.1. The setting of the sodium chloride layer or the potassium chloride layer can improve the thermal conductivity and fluidity of the metal layer 1, making the welding more stable, and at the same time can also reduce the pores in the welding process of the metal layer 1 and improve the strength and sealing of the weld; the setting of the thickness ratio can not affect the ability of the improved coating 3 to increase the metal layer 1 to adsorb the active material layer 2.

[0043] The other structures are the same as those in the first embodiment and will not be described again here.

[0044] Implementation Method 3

[0045] A battery includes a pole piece structure of a battery according to any one of embodiments one to two. The battery may be a lithium ion battery, a sodium ion battery, a magnesium ion battery, etc.

[0046] Implementation Method 4

[0047] An electrical device, including a battery of embodiment three. The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc.; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc.; the electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0048] According to the disclosure and teaching of the above description, the technicians in the field of the utility model can also change and modify the above implementation. Therefore, the utility model is not limited to the above specific implementation, and any obvious improvement, replacement or modification made by the technicians in this field on the basis of the utility model belongs to the protection scope of the utility model. In addition, although some specific terms are used in this specification, these terms are only for the convenience of explanation and do not constitute any limitation to the utility model.

Claims

1. A cathode electrode, characterized in that: It comprises a current collector, wherein the current collector is a metal layer (1), the upper and lower surfaces of the metal layer (1) are coated with active material layers (2), and the thickness of the metal layer (1) is not greater than 10 μm; Wherein, an improved coating (3) is provided between the metal layer (1) and the active material layer (2), and the improved coating (3) is coated on the upper and lower surfaces of the metal layer (1).

2. The cathode electrode according to claim 1, characterized in that: The coating area of ​​the improved coating (3) is the same as the area of ​​the metal layer (1).

3. The cathode electrode according to claim 1, characterized in that: The thickness of the improved coating (3) is 100nm-500nm.

4. The cathode electrode according to claim 1, characterized in that: The improved coating (3) has a substrate layer, and the substrate layer is one of aluminum oxide, zirconium oxide, titanium oxide or chromium oxide.

5. The cathode electrode according to claim 1, characterized in that: The improved coating (3) contains a sodium chloride layer or a potassium chloride layer, and the ratio of the thickness of the improved coating (3) to the thickness of the sodium chloride layer or the potassium chloride layer is 1:0.05-0.

1.

6. The cathode electrode according to claim 1, characterized in that: It also comprises empty foil areas (4), wherein the empty foil areas (4) and the active material layers (2) are arranged alternately along the surface of the improved coating (3).

7. The cathode electrode according to claim 6, characterized in that: The empty foil areas (4) are arranged on both sides of the metal layer (1), and the empty foil areas (4) on both sides are arranged correspondingly.

8. The cathode electrode according to any one of claims 1 to 7, characterized in that: The thickness of the metal layer (1) is 8 μm to 10 μm.

9. A battery, characterized in that: Comprising the cathode electrode piece as described in any one of claims 1-8.

10. An electrical device, characterized in that: Comprising the battery as claimed in claim 9.

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