Negative electrode structure of a full tab battery

Abstract

The utility model relates to power battery technical field, concretely relates to a kind of negative pole structure of full tab battery, including steel shell and pole group, the inner end surface of steel shell bottom is provided with welding area, welding area is provided with welding projection, welding projection can be circular ring protrusion, concentric protrusion, solenoid protrusion and radial protrusion, pole group is set in steel shell, when the copper foil of pole group negative pole end and welding machine protrusion are tightly contacted by exerting external force to pole group and steel shell, the negative pole end of pole group is welded with welding projection by laser welding or ultrasonic welding etc., steel shell is as the negative pole of pole group, omit collector plate, welding procedure is also simplified, and the internal resistance at negative pole structure is reduced.

Description

Technical Field

[0001] This utility model relates to the field of power battery technology, specifically to a negative electrode structure of a multi-tab battery. Background Technology

[0002] All-tab battery technology is maturing, significantly reducing internal resistance and heat generation by increasing the current conduction area and shortening the conduction distance. This technology can improve the rate performance of the battery, enabling fast charging and high-current discharge, while reducing temperature rise and extending cycle life.

[0003] To ensure welding strength, it is generally more secure and has lower resistance when welding similar metal parts together because they have the same melting point. However, most current all-tab batteries use resistance welding for the negative electrode, welding the copper side of the negative electrode current collector to the steel shell and the nickel side to the flattened copper foil negative electrode. This is because the welding needle of the resistance weld is made of copper, and if it comes into contact with the copper side, the two will stick together because they have the same melting point. This can lead to frequent replacement of the welding needle due to sparking, or even poor welding, incomplete welding, or no welding at all. The current collector, which is the intermediate part between the negative electrode and the steel shell, is only connected to the steel shell by the resistance weld point, which has certain limitations for high-current charging and discharging environments. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a negative electrode structure for a multi-tab battery, which reduces the number of negative electrode welding processes and components, reduces the occurrence of welding defects, lowers internal resistance, reduces costs and increases efficiency, and increases battery reliability.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: a negative electrode structure for a multi-tab battery, comprising a steel shell and an electrode assembly. A welding area is provided on the inner end face of the bottom of the steel shell, and welding protrusions are provided in the welding area. The electrode assembly is disposed inside the steel shell, and the negative terminal of the electrode assembly is welded to the welding protrusions. The negative terminal of the electrode assembly is welded to the welding area of ​​the steel shell. The steel shell serves as the negative electrode of the electrode assembly, eliminating the need for a current collector and simplifying the welding process.

[0006] As an optional technical solution of this utility model, the welding protrusion is a circular protrusion.

[0007] As an optional technical solution of this utility model, the welding protrusion includes multiple annular protrusions with different diameters, and the annular protrusions are distributed in a concentric circle.

[0008] As an optional technical solution of this utility model, the welding protrusion is a spiral protrusion.

[0009] As an optional technical solution of this utility model, the welding protrusion includes at least two straight protrusions arranged radially along the steel shell, and each straight protrusion is distributed circumferentially to form a radial protrusion.

[0010] As an optional technical solution of this utility model, the steel shell is a nickel-plated steel shell.

[0011] Compared with the prior art, the present invention has the following advantages: The negative electrode structure of the present invention omits the negative electrode current collector, which helps to reduce costs. Welding the negative electrode of the electrode group to the steel shell reduces a welding process compared with the existing structure with the negative electrode current collector, thereby avoiding defective products caused by this welding step and reducing the defect rate. Welding the negative electrode group to the steel shell effectively increases the welding area and reduces the internal resistance of the battery. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram showing the connection between the steel shell and the electrode assembly;

[0014] Figure 2 A partial structural diagram of the steel shell when the welded protrusion is a ring-shaped protrusion;

[0015] Figure 3 A schematic diagram of the welding zone when the welding protrusion is a ring-shaped protrusion;

[0016] Figure 4 A schematic diagram of the welding zone when the welding protrusion is a spiral-shaped protrusion;

[0017] Figure 5 A schematic diagram of the welding zone when the weld protrusions are radially shaped.

[0018] In the diagram: 1. Steel shell, 2. Electrode assembly, 3. Welded protrusion. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example

[0020] like Figures 1-5As shown, a negative electrode structure of a multi-tab battery includes a steel shell 1 and an electrode assembly 2. The steel shell 1 is a nickel-plated steel shell. A welding area is provided on the inner end face of the bottom of the steel shell 1, and a welding protrusion 3 is provided in the welding area. The electrode assembly 2 is disposed inside the steel shell 1, and the negative terminal of the electrode assembly 2 is welded to the welding protrusion 3. The copper foil at the negative terminal of the electrode assembly 2 is flattened or flattened and then contacts the welding area. The electrode assembly 2 is welded to the steel shell 1 from the outside of the steel shell 1 by means of laser welding, ultrasonic welding, etc. At the same time as welding, external force is applied to press the electrode assembly 2 and the steel shell 1 together to ensure a good contact effect between the steel shell 1 and the electrode assembly 2, thereby ensuring the welding strength.

[0021] Compared to the existing negative electrode structure of similar batteries, the negative electrode structure of this embodiment eliminates the negative electrode current collector, reducing costs; it simplifies the original method of welding both the electrode and the steel shell 1 to the current collector by welding the electrode group 2 to the steel shell 1, simplifying the welding process and effectively increasing the welding area between the negative electrode of the electrode group 2 and the steel shell 1, which helps to reduce internal resistance and improve battery performance.

[0022] Please see Figure 2 and Figure 3 As an optional implementation, the welding protrusion 3 can be one or more annular protrusions with different diameters. When the welding protrusion 3 includes multiple annular protrusions, the multiple annular protrusions are distributed in a concentric circle.

[0023] Please see Figure 4 As another alternative implementation, the welding protrusion 3 is a spiral protrusion.

[0024] Please see Figure 5 As another alternative implementation, the welding protrusion 3 includes at least two straight protrusions arranged radially along the bottom of the steel shell 1, and each straight protrusion is distributed circumferentially to form a radial protrusion.

[0025] After the copper foil at the negative end of electrode group 2 is flattened or patted flat, an external force is applied to electrode group 2 and steel shell 1, so that the copper foil at the negative end of electrode group 2 comes into contact with and is welded to the welding protrusion 3. Steel shell 1 serves as the output end of the negative electrode of electrode group 2.

[0026] In this specification, the terms "an embodiment," "example," "specific example," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. 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.

[0027] 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 negative electrode structure for a multi-tab battery, characterized in that: It includes a steel shell (1) and an electrode assembly (2). The inner end face of the bottom of the steel shell (1) is provided with a welding area and a welding protrusion (3). The electrode assembly (2) is located inside the steel shell (1) and the negative end of the electrode assembly (2) is welded to the welding protrusion (3).

2. The negative electrode structure of a multi-tab battery according to claim 1, characterized in that: The welding protrusion (3) is a ring-shaped protrusion.

3. The negative electrode structure of a multi-tab battery according to claim 2, characterized in that: The welding protrusion (3) includes multiple annular protrusions of different diameters, and each annular protrusion is distributed in a concentric circle.

4. The negative electrode structure of a multi-tab battery according to claim 1, characterized in that: The welding protrusion (3) is a spiral protrusion.

5. The negative electrode structure of a multi-tab battery according to claim 1, characterized in that: The welding protrusion (3) includes at least two straight protrusions arranged radially along the steel shell (1), each straight protrusion being distributed circumferentially and forming a radial protrusion.

6. The negative electrode structure of a multi-tab battery according to any one of claims 1-5, characterized in that: The steel shell (1) is a nickel-plated steel shell (1).

Images