Battery and electric device

Abstract

The utility model belongs to the technical field of battery structures, and particularly relates to a battery, which comprises a positive pole piece and a negative pole piece, the position of the positive pole piece corresponding to a tab groove is a prime coat area, one surface of a current collector positioned in the prime coat area, which faces the tab groove, is coated with an insulating prime coat, and the insulating prime coat is coated with a positive pole piece and a negative pole piece. A through groove is formed in the face, facing the tab groove, of the first active substance located in the prime coat area, the through groove is located above the insulation prime coat, the insulation prime coat is exposed at the bottom of the through groove, and the active substance in the middle of the through groove is a second active substance. The through groove is arranged between the second active material and the first active material, and the insulating prime coat is arranged between the second active material and the current collector. Through the arrangement of the through groove and the insulation prime coat, the second active substance has no electrochemical property, so that adhesive paper does not need to be pasted at the position, and the flatness of the battery cell is improved. In addition, the utility model also discloses an electric device comprising the battery.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery structure, and in particular relates to 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] Among them, the battery cell can be divided into a laminated battery cell and a wound core. In the field of power lithium batteries, the wound core structure is more common. After the battery cell with a central lug structure is wound, adhesive tape is usually pasted on the welding position of the positive electrode corresponding to the negative electrode lug to prevent the negative electrode welding burr from piercing the diaphragm and contacting the positive electrode to cause a short circuit. However, the above-mentioned adhesive tape method will increase the thickness of the lug position in the battery cell and affect the flatness of the battery cell. 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 utility model is to address the deficiencies of the prior art and provide a battery, which can insulate the second active material, the first active material and the current collector by providing an insulating primer and a through groove on the positive electrode plate, so that when a burr at the negative electrode ear welding point of the negative electrode plate passes through the diaphragm and contacts the second active material, the positive and negative electrodes will not be connected to cause a short circuit, so that there is no need to stick adhesive tape here, thereby improving the flatness of the battery cell.

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

[0006] A battery, comprising a positive electrode plate and a negative electrode plate insulated from the positive electrode plate by a separator, the positive electrode plate comprising a current collector and a first active material coated on both sides of the current collector, the negative electrode plate being provided with a tab groove, a negative electrode tab being provided in the tab groove, a primer region corresponding to the tab groove of the positive electrode plate, an insulating primer being applied to a side of the current collector located in the primer region facing the tab groove, and a through groove being provided to a side of the first active material located in the primer region facing the tab groove;

[0007] Among them, in the height direction of the positive electrode plate, the through groove is located above the insulating primer, the insulating primer is exposed at the bottom of the through groove, the through groove is arranged in a U-shaped structure, the active material in the middle of the through groove is the second active material, the through groove is arranged between the second active material and the first active material, and the insulating primer is arranged between the second active material and the current collector.

[0008] As an improvement of the battery described in the utility model, the material of the insulating primer is an insulating material such as ceramics, insulating glue, etc.

[0009] As an improvement of the battery described in the utility model, the insulating primer completely covers the side of the through groove in contact with the current collector, thereby preventing the second active material from being electrically connected to the current collector.

[0010] As an improvement of the battery described in the utility model, in the horizontal axis direction, the width W1 of the tab groove and the width W2 of the insulating primer satisfy the relationship: W1<W2.

[0011] As an improvement of the battery described in the utility model, the width W1 of the tab groove and the width W2 of the insulating primer preferably satisfy the relationship: 10mm≤W2-W1≤20mm.

[0012] As an improvement of the battery described in the utility model, in the vertical axis direction, the length L1 of the tab groove and the length L2 of the insulating primer satisfy the relationship: L1<L2.

[0013] As an improvement of the battery described in the utility model, the length L1 of the tab groove and the length L2 of the insulating primer preferably satisfy the relationship: 10mm≤L2-L1≤20mm.

[0014] As an improvement of the battery described in the utility model, in the horizontal axis direction, the through groove has a first width W3, and the first width W3, the width W1 of the tab groove and the width W2 of the insulating primer satisfy the relationship: W1≤W3≤W2.

[0015] As an improvement of the battery described in the utility model, in the horizontal axis direction, the through groove has a second width W4, and the second width W4 satisfies the relationship: 2mm≤W4≤10mm.

[0016] As an improvement of the battery described in the utility model, in the vertical axis direction, the length L1 of the tab groove, the length L2 of the insulating primer and the length L3 of the through groove satisfy the relationship: L1≤L3≤L2.

[0017] As an improvement of the battery described in the utility model, the horizontal axis direction, the vertical axis direction and the height direction are perpendicular to each other and correspond to the X-axis direction, the Y-axis direction and the Z-axis direction respectively.

[0018] The setting of the above numerical relationship can ensure that the second active material can be insulated from the current collector and the first active material while satisfying the electrical properties required by the positive electrode plate.

[0019] As an improvement of the battery described in the utility model, an identification primer is provided at the edge of the positive electrode sheet corresponding to the primer area, and the identification primer is coated on the current collector.

[0020] The second purpose of the utility model is to provide an electrical device, comprising the battery as described above.

[0021] The beneficial effect of the utility model lies in that the battery of the utility model comprises a positive electrode plate and a negative electrode plate insulated from the positive electrode plate by a diaphragm, the positive electrode plate comprises a current collector and a first active material coated on both sides of the current collector, the negative electrode plate is provided with a pole lug groove, a negative pole lug is provided in the pole lug groove, the corresponding part of the positive electrode plate and the pole lug groove is a primer area, the current collector located in the primer area is coated with an insulating primer on one side facing the pole lug groove, and the first active material located in the primer area is provided with a through groove on one side facing the pole lug groove; wherein, in the height direction of the positive electrode plate, the through groove is located above the insulating primer, the insulating primer is exposed at the bottom of the through groove, the through groove is provided with a U-shaped structure, the active material in the middle of the through groove is a second active material, the through groove is provided between the second active material and the first active material, and the insulating primer is provided between the second active material and the current collector. The winding core of the battery in the utility model is a winding core with a central ear structure, and the place where the positive electrode piece corresponds to the negative electrode piece welding ear is a primer area. By arranging an insulating primer and a through groove in the primer area of ​​the positive electrode piece, the second active material surrounded by the through groove can be insulated from the first active material and the current collector, and has no electrochemical properties. When the burr of the negative electrode piece welding ear penetrates the diaphragm and contacts the second active material, the positive and negative electrodes will not contact each other to cause a short circuit, so that there is no need to stick adhesive tape here, the thickness of the ear can be reduced, and the flatness of the battery cell is improved, and the belt breakage during rolling is prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The features, advantages and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

[0023] Figure 1 This is one of the structural schematic diagrams of the positive electrode plate in the utility model.

[0024] Figure 2 It is a schematic diagram of the structure of the negative electrode plate in the utility model.

[0025] Figure 3 It is a cross-sectional schematic diagram of the positive electrode sheet in the utility model.

[0026] Figure 4 This is the second structural schematic diagram of the positive electrode plate in the utility model (without the first active material).

[0027] The reference numerals are described as follows:

[0028] 1-positive electrode plate; 11-current collector; 111-insulating primer; 112-identification primer; 12-first active material; 121-through groove; 13-second active material;

[0029] 2-negative electrode plate; 21-ear slot; 22-negative electrode ear;

[0030] Z-height direction; X-horizontal axis direction; Y-vertical axis direction. DETAILED DESCRIPTION

[0031] 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.

[0032] 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.

[0033] 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.

[0034] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0035] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0036] The battery includes a cell and an electrolyte, and the cell is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive first active material, the positive electrode first active material is coated on the surface of the positive electrode collector, the positive electrode collector not coated with the positive first active material protrudes from the positive electrode collector coated with the positive first active material, and the positive electrode collector not coated with the positive first active material serves as a positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode collector and a negative first active material, the negative electrode first active material is coated on the surface of the negative electrode collector, the negative electrode collector not coated with the negative first active material protrudes from the negative electrode collector coated with the negative first active material, and the negative electrode collector not coated with the negative first active material serves as a negative electrode tab. The negative electrode current collector may be made of copper, and the negative electrode active material may be carbon or silicon. In order to ensure that a large current can pass without melting, the positive electrode tabs are multiple and stacked together, and the negative electrode tabs are multiple and stacked together. The material of the diaphragm may be PP (polypropylene) or PE (polyethylene).

[0037] The inventor found that after the battery cell with the center-tab structure is wound, the positive electrode sheet corresponding to the negative electrode tab welding position usually needs to be affixed with green glue to prevent the negative electrode welding burr from piercing the diaphragm and contacting the positive electrode to cause a short circuit. This glue-affixing method will increase the thickness of the tab position and affect the flatness of the battery cell. In view of this, the embodiment of the present application provides a technical solution, which can make the active material corresponding to the negative electrode tab welding position lose its electrochemical properties by setting a through groove and an insulating primer on the positive electrode sheet corresponding to the negative electrode tab welding position. It can replace the adhesive tape to prevent the burr from piercing the diaphragm and causing the positive and negative electrodes to connect and then short-circuit, so that the battery in this embodiment does not need to stick adhesive tape here, thereby improving the flatness of the battery cell.

[0038] The following is combined with Figures 1 to 4 The utility model is further described in detail with specific implementation modes, but is not intended to limit the utility model.

[0039] A battery, wherein the battery cell is a winding structure with a tab in the middle, the battery cell comprises a positive electrode sheet 1 and a negative electrode sheet 2 insulated from the positive electrode sheet 1 by a diaphragm, the positive electrode sheet 1 comprises a current collector 11 and a first active material 12 coated on both sides of the current collector 11, the negative electrode sheet 2 is provided with a tab groove 21, a negative electrode tab 22 is provided in the tab groove 21, the corresponding part of the positive electrode sheet 1 and the tab groove 21 is a primer area, the current collector 11 located in the primer area is coated with an insulating primer 111 on one side facing the tab groove 21, and the first active material 12 located in the primer area is provided with a through groove 121 on one side facing the tab groove 21;

[0040] Among them, in the height direction Z of the positive electrode plate 1, the through groove 121 is located above the insulating primer 111, the insulating primer 111 is exposed at the bottom of the through groove 121, the through groove 121 is arranged in a U-shaped structure, the active material in the middle of the through groove 121 is the second active material 13, the through groove 121 is arranged between the second active material 13 and the first active material 12, and the insulating primer 111 is arranged between the second active material 13 and the current collector 11.

[0041] In this embodiment, the material of the insulating primer 111 is one of other insulating materials such as ceramics and insulating glue, which ensures that the second active material 13 is insulated from the current collector 11. The insulating primer 111 completely covers the side of the second active material 13 that is in contact with the current collector 11, avoiding electrical connection between the second active material 13 and the current collector 11.

[0042] In this embodiment, the through groove 121 of the U-shaped structure can create a gap between the second active material 13 and the first active material 12, thereby avoiding electrical connection between the second active material 13 and the first active material 12. It is understandable that in some other embodiments, the through groove 121 can also be set to a ring structure, as long as the second active material 13 can be insulated and isolated from the first active material 12, without making any specific settings.

[0043] The provision of the through groove 121 and the insulating primer 111 causes the second active material 13 to lose its electrochemical properties. When the burrs at the negative electrode tab 22 where the negative electrode sheet 2 is welded pass through the diaphragm and come into contact with the second active material 13, since the second active material 13 does not have any electrochemical properties, the positive and negative electrodes will not be connected to cause a short circuit. That is, the second active material 13 can replace the role of the adhesive tape, so that the coating area does not need to be pasted with adhesive tape, and the thickness of the coating area will not increase due to the adhesive, thereby increasing the flatness of the battery cell and reducing the possibility of tape breakage during rolling.

[0044] It is understandable that in other technical solutions, the height of the second active material 13 in the height direction Z can be reduced, and adhesive tape can be pasted on the side of the second active material 13 facing the pole ear groove 21, which can further prevent burrs from causing short circuits at the junction of the positive and negative electrodes without affecting the flatness of the battery cell.

[0045] In this embodiment, the horizontal axis direction X, the vertical axis direction Y and the height direction Z are perpendicular to each other and correspond to the X-axis direction, the Y-axis direction and the Z-axis direction respectively.

[0046] Preferably, an identification primer 112 is provided at the edge of the primer area corresponding to the positive electrode plate 1 . The identification primer 112 is coated on the current collector 11 . The identification primer 112 is used to increase the accuracy of laser cleaning of the through groove 121 .

[0047] Preferably, in the horizontal axis direction X, the width W1 of the tab groove 21 and the width W2 of the insulating primer 111 satisfy the relationship: W1<W2, and the relationship is preferably 10mm≤W2-W1≤20mm; in the vertical axis direction Y, the length L1 of the tab groove 21 and the length L2 of the insulating primer 111 satisfy the relationship: L1<L2, and the relationship is preferably 10mm≤L2-L1≤20mm; in the horizontal axis direction X, the through groove 121 has the first A width W3, the first width W3, the width W1 of the tab groove 21 and the width W2 of the insulating primer 111 satisfy the relationship: W1≤W3≤W2; in the horizontal axis direction X, the through groove 121 has a second width W4, and the second width W4 satisfies the relationship: 2mm≤W4≤10mm; in the vertical axis direction Y, the length L1 of the tab groove 21, the length L2 of the insulating primer 111 and the length L3 of the through groove 121 satisfy the relationship: L1≤L3≤L2.

[0048] In this embodiment, the width of the pole ear groove 21 is 15mm and the length is 20mm; the width of the insulating primer 111 is 25-35mm, preferably 30mm, and the length is 30-40mm, preferably 35mm; the first width of the through groove 121 is 15-25mm, preferably 20mm, and the length is 20-30mm, preferably 25mm, and the second width is 2-10mm, preferably 5mm.

[0049] In order to verify the beneficial effects of this embodiment, the following examples are set for experiment:

[0050] A negative electrode plate 2 is manufactured, a tab groove 21 is provided on the negative electrode plate 2, and a negative electrode tab 22 is welded in the tab groove 21; a positive electrode plate 1 is manufactured, an insulating primer 111 is coated on the current collector 11 located in the coating area, and after single-sided and double-sided coating is completed with the current collector 11 coated with the insulating primer 111, a laser cleaning process is performed, and the first active material 12 above the insulating primer 111 is cleaned out of a through groove 121 by adjusting the laser power; a wound cell is manufactured by using the positive electrode plate 1, the negative electrode plate 2 and the diaphragm, the wound cell is put into a shell and filled with liquid to obtain a battery, the battery is fully charged and then disassembled to observe whether there is a short circuit in the coating area; the parameters of the tab groove 21, the insulating primer 11 and the through groove 121 in each battery obtained and the experimental results are shown in Table 1.

[0051] Table 1

[0052]

[0053] According to the above table, the second active material 13 in this embodiment can replace the adhesive tape to prevent burrs from piercing the diaphragm and causing a short circuit between the positive and negative electrodes, so that there is no need to stick adhesive tape on the coated area, thereby improving the flatness of the battery cell and preventing the tape from breaking during rolling.

[0054] Electrical devices

[0055] An electrical device includes the above-mentioned battery, and the battery can be a lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc. Among them, the electrical device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, and an electric tool. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft; 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; 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. The embodiment of the present application does not impose any special restrictions on the above-mentioned electrical devices.

[0056] 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 battery, comprising a positive electrode sheet (1) and a negative electrode sheet (2) insulated from the positive electrode sheet (1) by a separator, wherein the positive electrode sheet (1) comprises a current collector (11) and a first active material (12) coated on both sides of the current collector (11), the negative electrode sheet (2) is provided with a tab groove (21), and a negative electrode tab (22) is provided in the tab groove (21), characterized in that: The portion of the positive electrode sheet (1) corresponding to the tab groove (21) is a primer area, the current collector (11) located in the primer area is coated with an insulating primer (111) on one side facing the tab groove (21), and the first active material (12) located in the primer area is provided with a through groove (121) on one side facing the tab groove (21); Wherein, in the height direction (Z) of the positive electrode plate (1), the through groove (121) is located above the insulating primer (111), the insulating primer (111) is exposed at the bottom of the through groove (121), the through groove (121) is arranged in a U-shaped structure, the active material in the middle of the through groove (121) is a second active material (13), the through groove (121) is arranged between the second active material (13) and the first active material (12), and the insulating primer (111) is arranged between the second active material (13) and the current collector (11).

2. The battery according to claim 1, characterized in that In the horizontal axis direction (X), the width W1 of the tab groove (21) and the width W2 of the insulating primer (111) satisfy the relationship: W1<W2.

3. The battery according to claim 1, characterized in that In the horizontal axis direction (X), the width W1 of the tab groove (21) and the width W2 of the insulating primer (111) satisfy the relationship: 10 mm ≤ W2 - W1 ≤ 20 mm.

4. The battery according to claim 1, characterized in that In the vertical axis direction (Y), the length L1 of the tab groove (21) and the length L2 of the insulating primer (111) satisfy the relationship: L1<L2.

5. The battery according to claim 1, characterized in that In the vertical axis direction (Y), the length L1 of the tab groove (21) and the length L2 of the insulating primer (111) satisfy the relationship: 10 mm ≤ L2 - L1 ≤ 20 mm.

6. The battery according to claim 2 or 3, characterized in that: In the horizontal axis direction (X), the through groove (121) has a first width W3, and the first width W3, the width W1 of the tab groove (21) and the width W2 of the insulating primer (111) satisfy the relationship: W1≤W3≤W2.

7. The battery according to claim 6, characterized in that In the transverse axis direction (X), the through groove (121) has a second width W4, and the second width W4 satisfies the relationship: 2mm≤W4≤10mm.

8. The battery according to claim 4 or 5, characterized in that In the vertical axis direction (Y), the length L1 of the tab groove (21), the length L2 of the insulating primer (111), and the length L3 of the through groove (121) satisfy the relationship: L1≤L3≤L2.

9. The battery according to claim 1, characterized in that An identification primer (112) is provided at the edge of the positive electrode plate (1) corresponding to the primer area, and the identification primer (112) is coated on the current collector (11).

10. An electrical device, characterized in that: Comprising a battery as claimed in any one of claims 1 to 9.

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