Large cylindrical battery roll core

Abstract

The utility model belongs to the technical field of large cylindrical batteries, and particularly relates to a large cylindrical battery roll core, which comprises a roll core, the roll core comprises a positive pole piece, a negative pole piece and a diaphragm, the battery also comprises a plurality of foils, the plurality of foils are arranged on the end face of the roll core, and the top end of each foil is provided with a rolling plane; the flow collecting plate is welded on the kneading plane; the heat conduction substance is arranged below the kneading plane and above the positive pole piece; the heat conduction material is an insulating material; the end face of the roll core adopts one of a cutting and stacking process and a kneading and flattening process; according to the utility model, the heat conduction material is filled between the welding plane on the roll core and the positive electrode material (the light foil area), so that the welding heat is transferred to other pole pieces which do not participate in welding, friendly process conditions are provided for welding the collector plate, and meanwhile, the filled heat conduction material plays a role in enhancing the structural strength of the roll core.

Description

Technical Field

[0001] This utility model relates to the field of large cylindrical battery technology, and in particular to a large cylindrical battery core. Background Technology

[0002] Traditional cylindrical battery single-tab structures, when applied to large cylindrical batteries, suffer from increased internal resistance, weak overcurrent capacity, and short cycle life. Large cylindrical batteries often employ a full-tab structure, requiring the tabs to be welded to the current collector, with the current collector pressing on top of the tabs and the laser striking the current collector. Due to the full-tab structure, the tabs are essentially electrode foils, and air exists between the foils. Air is a poor conductor of heat, hindering heat dissipation. Therefore, the heat from laser welding is transferred along the foil into the core, melting the separator below the welding path. Once the separator melts, the positive and negative electrodes come into contact, causing a short circuit. How to prevent the separator from melting during laser welding of the current collector and core foil, and improve product yield, has become a pressing problem for the mass production of large cylindrical batteries. Therefore, this application proposes a large cylindrical battery core to solve the above problems. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies where, due to the all-tab structure (where the tabs are electrode foils with air gaps between them), the heat from laser welding is transferred along the foils into the core, melting the separator below the welding path. This melting of the separator leads to contact between the positive and negative electrodes, causing a short circuit. This invention proposes a large cylindrical battery core.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A large cylindrical battery core includes a core comprising a positive electrode sheet, a negative electrode sheet, and a separator. The battery also includes:

[0006] The foil is provided in multiple forms, and each foil is disposed on the end face of the core, with a crumpled surface provided at the top of the foil.

[0007] A collector plate, wherein the collector plate is welded onto the kneading surface;

[0008] A thermally conductive material is disposed below the kneading plane and above the positive electrode plate.

[0009] In a preferred embodiment of this invention, the thermally conductive material is made of silicone or UV adhesive.

[0010] As a preferred embodiment of this utility model, the end face of the core is subjected to processes such as cutting, stacking, and kneading.

[0011] In a preferred embodiment of this invention, the thermally conductive material does not participate in the internal chemical reaction of the battery.

[0012] In a preferred embodiment of this invention, gaps are provided between the plurality of foils, and thermally conductive material is filled in the gaps.

[0013] In a preferred embodiment of this invention, the thermally conductive material is an insulating material. Beneficial effects

[0014] 1. The above-mentioned heat-conducting material fills the gap between the electrode and the foil. During laser welding, it intercepts the heat that is longitudinally transmitted to the separator and diffuses this heat laterally to the non-welding area. The heat is then dissipated into the air, preventing the heat from being transmitted longitudinally and melting the separator below the welding area, thus avoiding short circuits and explosions caused by the melting of the separator in the battery.

[0015] 2. The above-mentioned thermally conductive materials can improve battery performance, reduce the mutual reaction between the positive electrode material and the electrolyte, and avoid electrolyte loss and electrode surface damage.

[0016] 3. The above-mentioned thermally conductive materials improve battery safety performance. The foil area is relatively fragile, and filling it with thermally conductive materials provides support.

[0017] This invention fills the space between the welding plane on the core and the positive electrode material (the foil area) with a thermally conductive material, transferring the welding heat to other electrodes that do not participate in the welding. This provides favorable process conditions for welding the current collector, while the filled thermally conductive material also enhances the structural strength of the core. Attached Figure Description

[0018] Figure 1 This is a front view of the structure of this utility model;

[0019] Figure 2 This is a front view of the structure of the positive electrode, negative electrode, separator, and foil of this utility model;

[0020] Figure 3 This is a front view of the structure of the positive electrode, negative electrode, diaphragm, and flat surface of this utility model.

[0021] In the diagram: 1. Core; 11. Positive electrode sheet; 12. Negative electrode sheet; 13. Diaphragm; 2. Thermally conductive material; 3. Foil material; 4. Flat surface; 5. Collector plate. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Example

[0023] Reference Figures 1-3 A large cylindrical battery core includes a core 1, which comprises a positive electrode 11, a negative electrode 12, and a separator 13. The battery also includes:

[0024] Foil 3, which is provided in multiple forms, and multiple foils 3 are all provided on the end face of the core 1. The top of the foil 3 is provided with a crumpled surface 4.

[0025] The collector plate 5 is welded onto the kneading surface 4;

[0026] Thermally conductive material 2 is placed below the kneading plane 4 and above the positive electrode plate 11.

[0027] As a preferred embodiment of this utility model, the thermally conductive material 2 is made of silicone, UV adhesive, or other materials with similar properties.

[0028] As a preferred embodiment of this utility model, the end face of the core 1 is subjected to processes such as cutting, stacking, and kneading.

[0029] As a preferred embodiment of this invention, the thermally conductive material 2 does not participate in the internal chemical reaction of the battery.

[0030] As a preferred embodiment of this utility model, gaps are provided between the multiple foils 3, and the thermally conductive material 2 is filled in the gaps.

[0031] As a preferred embodiment of this utility model, the thermally conductive material 2 is an insulating material. Example

[0032] After the core 1 is wound, the positive electrode foil area is immersed in liquid thermally conductive material 2; the thermally conductive material 2 is dried and solidified by heating or UV lamp irradiation; the thermally conductive material 2 in the flattened area is removed, and the core 1 is flattened; the current collector 5 is welded to the core 1; the core 1 is disassembled, and the diaphragm 13 below the welding area is observed to be unmelted; in addition, the core 1 without thermally conductive material 2 is compared, the current collector 5 is welded, and after disassembly, the diaphragm 13 is partially melted.

[0033] The working principle of this utility model is as follows: In use, the production process of the core 1 generally requires processes such as material preparation, coating, rolling, slitting, winding, flattening, and assembly. Among them, the laser welding of the current collector 5 and the foil 3, the core 1 obtained after the winding process, the positive electrode foil area of ​​the core 1 is immersed in liquid heat-conducting material 2, the heat-conducting material 2 on the core 1 is dried and shaped, and then a certain length of heat-conducting material 2 on the outer side of the foil area is removed. The core 1 is then flattened, and after flattening, the current collector 5 is welded. During welding, the heat generated by the laser is mainly transferred to the surrounding area through the metal surface of the current collector 5; through the current collector 5, it is transferred to the interior of the core 1 through the foil 3; and through the heat-conducting material 2 on the foil 3, it is transferred to the foil 3 in the non-welding area.

[0034] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A large cylindrical battery jelly-roll, comprising a jelly-roll (1) including a positive electrode sheet (11), a negative electrode sheet (12), and a separator (13), characterized in that, The battery also includes: Foil (3), which is configured as multiple, and all of the multiple foils (3) are disposed on the end face of the core (1), and the top of the foil (3) is provided with a crumpled surface (4). A collector plate (5) is welded onto a flat surface (4); The thermally conductive material (2) is disposed below the kneading plane (4) and above the positive electrode plate (11).

2. The large cylindrical battery core according to claim 1, wherein The thermally conductive material (2) is an insulating material.

3. The large cylindrical battery core according to claim 1, wherein The end face of the core (1) is made using either a cutting and stacking process or a flattening process.

4. The large cylindrical battery core according to claim 1, wherein The thermally conductive material (2) does not participate in the internal chemical reaction of the battery.

5. The large cylindrical battery core according to claim 1, wherein, A gap is provided between the multiple foils (3), and the thermally conductive material (2) is filled in the gap.

6. The large cylindrical battery core according to claim 2, wherein The thermally conductive material (2) is made of either silicone or UV adhesive.

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