Lithium battery structure

Abstract

The utility model discloses a lithium battery structure which comprises a battery cell which is connected with a tab, a cover plate assembly is further included. The cover plate assembly comprises a terminal assembly and a substrate. The substrate is provided with a connecting position; the terminal assembly comprises a terminal substrate and a pole terminal, the terminal substrate is connected with the connecting position on the substrate in a matched mode, the pole terminal penetrates through the terminal substrate, and one end of the pole terminal is connected with the tab. According to the scheme, the cover plate substrate in the cover plate assembly is divided into the substrate and the terminal substrate, the terminal substrate and the pole terminal form the terminal assembly, the size of the terminal assembly is smaller than that of the opening of the shell, and before the battery cell enters the shell, the tab and the terminal assembly can be welded and connected firstly, so that the distance between the battery cell and the terminal assembly is shortened; therefore, the size of the battery cell pole piece can be lengthened, and the space for storing the long tab in the traditional design is used for filling the pole piece, so that the battery capacity is increased.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and more specifically, to a lithium battery structure. Background Technology

[0002] In the energy storage and power battery industries, the demand for high-capacity and high-rate charge / discharge capabilities is becoming increasingly urgent, providing new impetus and direction for battery technology development. However, increasing battery capacity also leads to an increase in battery thickness, which brings a series of challenges. For example, the length and thickness of the tabs increase, and bending the tabs requires more space, which is not conducive to improving the energy density of the battery pack. In addition, the length, width, and height dimensions of battery cells vary for different batteries, especially the height. The same production line cannot be compatible with cells of different heights, resulting in wasted production lines. Utility Model Content

[0003] This invention provides a lithium battery structure to solve the problem of excessive space occupied by existing battery cell tabs.

[0004] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0005] A lithium battery structure includes a cell connected to tabs;

[0006] It also includes a cover plate assembly; the cover plate assembly includes a terminal assembly and a substrate;

[0007] The substrate has a connection position; the terminal assembly includes a terminal substrate and a pole terminal, the terminal substrate is connected to the connection position on the substrate, the pole terminal passes through the terminal substrate and one end of the pole terminal is connected to the tab.

[0008] In this solution, the cover plate substrate in the cover plate assembly is divided into a substrate and a terminal substrate. The terminal substrate and the electrode terminal together form a terminal assembly. The terminal assembly is smaller than the opening size of the housing. Before the cell enters the housing, the electrode tabs can be welded to the terminal assembly, which shortens the distance between the cell and the terminal assembly. This allows the size of the cell electrode to be increased, and the space used to store the long electrode tabs in the traditional design can be used to fill the electrode, thus increasing the battery capacity.

[0009] As a further improvement, the tabs include a positive tab and a negative tab. The terminal assembly is connected to the positive and negative tabs respectively, which on the one hand further shortens the length of the tabs and increases the battery capacity; more importantly, the battery does not need to be flipped during production, simplifying the processing technology and enabling the production line to be compatible with the production of batteries of different heights.

[0010] As a further improvement, the tabs are located at both ends of the battery cell, and the connection position on the substrate is set to one, which is suitable for situations where the battery has tabs at both ends.

[0011] As a further improvement, the tabs are located on the same side of the battery cell, and there are two connection positions on the substrate, which is suitable for situations where the tabs are located on the same side of the battery.

[0012] As a further improvement, a first step is provided at the connection between the terminal substrate and the substrate, and an outer step is provided at the connection between the substrate and the terminal substrate. The first step overlaps on the outer step, which ensures a stable fit between the terminal assembly and the connection position and enhances the structural stability of the battery.

[0013] As a further improvement, the substrate is connected to the battery casing, and an inner step is provided at the connection between the substrate and the battery casing to avoid mutual interference between the battery components during the installation process, thereby improving assembly efficiency and accuracy.

[0014] As a further improvement, the height of the outer step is 40% to 50% of the thickness of the substrate. While forming the outer step, the strength requirements of the connection side of the substrate are also met.

[0015] As a further improvement, the inner step is inclined to help guide the correct connection between the substrate and the housing.

[0016] As a further improvement, the battery cell is square.

[0017] As a further improvement, the battery cell is cylindrical.

[0018] Other technical problems that the lithium battery structure of this utility model can solve, other technical features contained in the technical solution, and the advantages brought by these technical features will be further explained in detail with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall battery structure;

[0020] Figure 2 This is a schematic diagram showing the connection between the battery cell and the terminal assembly;

[0021] Figure 3 This is a schematic diagram of the substrate structure;

[0022] Figure 4 This is a schematic diagram of the external step structure;

[0023] Figure 5 This is a schematic diagram of the internal stepped structure;

[0024] Figure 6 This is a schematic diagram of the substrate structure in another embodiment;

[0025] Figure 7 This is a schematic diagram showing the connection between the electrode tab and the terminal assembly;

[0026] Figure 8 This is a schematic diagram comparing the connection with existing battery cell tabs.

[0027] Label Explanation:

[0028] 1. Terminal assembly; 101. Terminal substrate; 102. Pole terminal; 2. Substrate; 201. Outer step; 202. Arc-shaped opening; 203. Inner step; 3. Stop frame; 4. Battery cell; 401. Pole tab; 5. Housing. Detailed Implementation

[0029] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0030] The structures, proportions, and sizes illustrated in the accompanying drawings are solely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0031] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein.

[0032] Combination Figure 1 , Figure 2 and Figure 6 As shown, this embodiment provides a lithium battery structure, including a cell 4, and the cell 4 is connected to a tab 401.

[0033] It should be noted that cell 4 can be either square or cylindrical. When cell 4 is square, it can be a single-wound cell, a double-wound cell, or a multi-wound cell.

[0034] For ease of explanation, this embodiment uses cell 4 as a square cell that is either a single stacked core or a single wound core.

[0035] The lithium battery structure also includes a cover plate assembly. Specifically, the cover plate assembly includes a terminal assembly 1 and a substrate 2. The substrate 2 has connection positions; the terminal assembly 1 includes a terminal substrate 101 and a terminal post 102. The terminal substrate 101 is connected to the connection positions on the substrate 2. The terminal post 102 passes through the terminal substrate 101 and one end of the terminal post 102 is connected to the tab 401.

[0036] Combination Figure 8 As shown, Figure 8 The battery in section b uses a traditional cover plate assembly structure. Figure 8 The battery in section a uses the cover plate assembly structure of this embodiment. In a traditional cover plate assembly, the cover plate substrate is a single piece. In this case, during battery assembly, the housing 5 needs to be assembled first, and then the cover plate assembly is assembled. Thus, the cover plate assembly needs to be outside the housing, or at worst, tightly attached to the housing. In order to connect with the terminal posts in the cover plate assembly, the cells inside the housing need to have longer tabs extending out to be welded to the terminal posts. However, after bending and assembling the longer tabs, more internal space is needed to store the tabs, which is not conducive to improving the energy density of the battery.

[0037] In this embodiment, combined with Figure 7 As shown, in this embodiment, the cover plate assembly includes a terminal assembly 1 and a substrate 2. The terminal assembly 1 includes a terminal substrate 101 and a terminal post 102. The terminal substrate 101 is connected to the connection point on the substrate 2. In this way, the cover plate substrate in the cover plate assembly is divided into substrate 2 and terminal substrate 101. The terminal substrate 101 and the terminal post 102 together form the terminal assembly 1, and the terminal assembly 1 can be pre-assembled. In this case, the terminal assembly 1 is smaller than the opening size of the housing. Before the cell 4 enters the housing 5, the tab 401 can be welded to the terminal assembly 1, shortening the distance between the cell 4 and the terminal assembly 1. The required length of the tab will also be shortened. Under the same internal space of the battery, the size of the cell electrode can be increased. The space used to store the long tab in the traditional design can be used to fill the electrode, thus increasing the battery capacity.

[0038] Combination Figure 2 As shown, tab 401 includes a positive tab and a negative tab. It should be noted that in this embodiment, both the positive and negative tabs are centered and joined together, thus maximizing the use of the limited tab length to form a battery that is as thick as possible. "Centered and joined together" means that after the tabs are joined, they form a tab cluster, with the center of the tab cluster located in the middle of the side of the cell containing the tab. In other cases, for batteries with relatively thin cells, the tabs can be joined centered or offset. Similarly, the terminal post 102 is adjusted accordingly in position to the terminal assembly 1 so that the terminal post 102 and the tab 401 are connected.

[0039] It should also be noted that the terminal 102 is also divided into a positive terminal and a negative terminal. The positive terminal is connected to the positive tab, and the negative terminal is connected to the negative tab. In this design, both the positive and negative tabs of the battery cell are connected to the terminal assembly 1. Figure 1 The direction shown in the diagram is explained as follows: During cell assembly, the side formed in the length-to-height direction is laid flat on the production line, and terminal assembly 1 is connected to the positive and negative tabs respectively. This further shortens the length of the tabs and increases the battery capacity. Furthermore, unlike traditional batteries where the tabs are connected to the terminal posts in the cover plate using a butterfly welding method, and the battery is then flipped and placed vertically (with the side formed in the length-to-width direction laid flat on the production line) before subsequent processes, this solution eliminates the need for vertical placement of the cell, allowing the production line to accommodate batteries of different heights.

[0040] In this embodiment, the tabs 401 are located at both ends of the battery cell 4, and the connection position on the substrate 2 is set to one, such as... Figure 3 As shown. In another embodiment, the tab 401 is located on the same side of the cell 4, and the connection position on the substrate 2 is set to two, as shown. Figure 5 As shown.

[0041] The connection position is U-shaped with an opening at one end, which facilitates the installation of terminal assembly 1 and simplifies the connection process between terminal assembly 1 and substrate 2.

[0042] Combination Figure 3 and Figure 4 As shown, to prevent interference between the components of the prismatic battery during installation, steps or chamfers are required at specific locations. A first step is formed at the connection between the terminal substrate 101 and the substrate 2, and an outer step 201 is formed at the connection between the substrate 2 and the terminal substrate 101, with the first step overlapping the outer step 201. The substrate 2 is connected to the battery casing 5, and an inner step 203 is provided at the connection between the substrate 2 and the battery casing 5. The height of the outer step 201 is 40% to 50% of the thickness of the substrate 2. The inner step 203 is inclined.

[0043] An arc-shaped opening 202 is provided at the connection point of the connection position of the substrate 2 at the adjacent side connection, thereby increasing the structural strength of the substrate 2 and avoiding stress concentration.

[0044] It should be noted that in the above structure, by setting steps or chamfers at specific locations, such as the outer step 201 and the inner step 203, mutual interference between battery components during installation can be effectively avoided, thereby improving assembly efficiency and accuracy. Furthermore, the overlapping design of the first step and the outer step 201 ensures a stable fit between the terminal assembly 1 and the connection point, enhancing the structural stability of the battery. The inclined setting of the inner step 203 helps guide the correct connection between the substrate 2 and the housing 5. Therefore, the above design features not only optimize the battery installation process but also improve the overall performance and reliability of the battery.

[0045] It should be further noted that the terminal substrate 101 on the terminal assembly 1 can be made of the same material as the substrate 2, such as steel, aluminum or other metals, or plastic.

[0046] The lithium battery structure also includes a stop frame 3, the battery cell 4 is installed in the housing 5, the stop frame 3 is located at the end of the battery cell 4 where the terminal assembly 1 is installed; the substrate 2 is installed at the end of the stop frame 3 away from the battery cell 4 and is connected to the housing 5, the substrate 2 is provided with a connection position, and the terminal assembly 1 is embedded in the connection position.

[0047] In this scheme, the battery assembly process is as follows: first, the terminal assembly 1 is welded to the tab of the cell 4; then, the terminal assembly is passed through the stop frame 3, and the stop frame 3 is installed on the cell; then, Mylar film is wrapped and the Mylar film is hot-pressed onto the stop frame; then, the substrate 2 is passed through the tab and assembled with the shell and spot-welded to fix it, at which time the terminal assembly is located outside the substrate 2; then, the terminal assembly is assembled on the substrate 2, and the steps between them can be used as positioning references; then, the terminal assembly and the substrate are laser-welded to fix them; finally, the substrate, the terminal substrate and the shell are welded together.

[0048] The terms "installation," "setup," "equipped with," and "connection" used herein should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0049] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A lithium battery structure, comprising a cell (4), wherein the cell (4) is connected to a tab (401); Its features are: It also includes a cover plate assembly; the cover plate assembly includes a terminal assembly (1) and a substrate (2); The substrate (2) has a connection position; the terminal assembly (1) includes a terminal substrate (101) and a pole terminal (102). The terminal substrate (101) is connected to the connection position on the substrate (2). The pole terminal (102) passes through the terminal substrate (101) and one end of the pole terminal (102) is connected to the tab (401).

2. The lithium battery structure according to claim 1, characterized in that: The tab (401) includes a positive tab and a negative tab.

3. The lithium battery structure according to claim 2, characterized in that: The tabs (401) are located at both ends of the battery cell (4), and the connection position on the substrate (2) is set to one.

4. The lithium battery structure according to claim 2, characterized in that: The tab (401) is located on the same side of the cell (4), and there are two connection points on the substrate (2).

5. The lithium battery structure according to claim 3 or 4, characterized in that: A first step is provided at the connection between the terminal substrate (101) and the substrate (2), and an outer step (201) is provided at the connection between the substrate (2) and the terminal substrate (101), with the first step overlapping the outer step (201).

6. The lithium battery structure according to claim 3 or 4, characterized in that: The substrate (2) is connected to the battery housing (5), and an inner step (203) is provided at the connection between the substrate (2) and the battery housing (5).

7. The lithium battery structure according to claim 5, characterized in that: The height of the outer step (201) is 40% to 50% of the thickness of the substrate (2).

8. The lithium battery structure according to claim 6, characterized in that: The inner step (203) is inclined.

9. The lithium battery structure according to claim 1, characterized in that: The battery cell (4) is square.

10. The lithium battery structure according to claim 1, characterized in that: The battery cell (4) is cylindrical.

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