Lithium ion battery and cover plate structure

Abstract

The utility model discloses a lithium ion battery and a cover plate structure, and belongs to the technical field of lithium ion batteries, the battery comprises a battery cell, the cover plate structure and a shell, the cover plate structure and the shell form a closed space, and the battery cell is arranged in the closed space and is electrically connected with the cover plate structure; the cover plate structure comprises a plurality of pole structures which are arranged at intervals and have the same polarity, the pole structures are connected through connecting piece structures with the corresponding polarity, and the connecting piece structures stretch across the pole structures; the battery cell is provided with a tab structure corresponding to the polarity of the connecting sheet structure, the span of the tab structure corresponds to the span of the connecting sheet structure, and the tab structure is connected with the connecting sheet structure. When the tab structure is connected with the connecting sheet structure, a larger connecting area is achieved, the over-current capability of the cover plate structure is improved, and the heating of the battery is relieved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion batteries, in particular to a lithium ion battery and a cover plate structure. Background Art

[0002] Lithium-ion batteries are currently the battery system with the best overall performance, boasting high specific energy, long cycle life, compact size, lightweight, no memory effect, and zero pollution. They are rapidly developing into a new generation of energy storage power sources, used to power information technology, electric and hybrid vehicles, aerospace, and other fields. Lithium batteries offer advantages such as high voltage, long life, high energy density, and lightweight design, and their application areas are constantly expanding. However, their safety is inferior to other secondary batteries. When a power lithium battery is overcharged, the electrolyte and other materials within it decompose to produce gas, causing the battery casing to bulge and rupture, allowing oxygen to enter and react with lithium ions accumulated on the negative electrode surface, leading to explosion.

[0003] In addition, the structure of conventional lithium batteries generates severe heat during high current charging and discharging due to the lack of overcurrent capacity of the cover plate, which makes explosion accidents more likely to occur. Utility Model Content

[0004] The purpose of the utility model is to provide a lithium-ion battery and a cover plate structure, which solves the problems of insufficient current flow capacity and severe heat generation of the lithium battery cover plate in the prior art.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a lithium-ion battery, comprising a battery cell, a cover structure and a shell, wherein the cover structure and the shell form a closed space, the battery cell is arranged in the closed space and is electrically connected to the cover structure; the cover structure includes a plurality of pole structures of the same polarity arranged at intervals, the pole structures are connected by connecting plate structures of corresponding polarities, and the connecting plate structure is arranged across multiple pole structures; the battery cell is provided with a tab structure corresponding to the polarity of the connecting plate structure, the span of the tab structure corresponds to the span of the connecting plate structure, and the tab structure is connected to the connecting plate structure.

[0006] The battery cover in the prior art is centrally provided with positive and negative poles, and the battery cells are connected to the positive and negative poles through positive and negative connecting plates. The positive and negative connecting plates are all concentrated under the same battery cover. However, the space under the battery cover is limited, and the positive and negative connecting plates share the same space, resulting in the volume of the positive and negative connecting plates being limited and the structure of the connection part with the battery cells being limited, resulting in poor cover current capacity and severe heat generation. However, the cover structure in the present invention is provided with a number of pole structures of the same polarity, and the connecting plate structure of the corresponding polarity spans across multiple pole structures and is connected to the pole structure. The length and area of ​​the connecting plate are relatively larger. In addition, the battery cells are also provided with a pole ear structure of the corresponding span. When the pole ear structure is connected to the connecting plate structure, it has a larger connection area, which improves the current capacity of the cover structure and alleviates battery heat generation. Moreover, the cover structure is provided with poles of the same polarity, which means that the positive cover structure and the negative cover structure are provided separately, providing more space to accommodate the tab structure and the connecting piece structure, greatly improving the current carrying capacity of the cover structure.

[0007] Furthermore, the cover plate structure includes a positive cover plate and a negative cover plate, and the positive cover plate and the negative cover plate are respectively located on both sides of the shell, and the positive cover plate is provided with a number of positive poles, and the negative cover plate is provided with a number of negative poles; several of the positive poles are connected by a positive connecting plate, and several of the negative poles are connected by a negative connecting plate.

[0008] The positive and negative electrode covers are located on either side of the housing, increasing the space beneath them and correspondingly increasing the area of ​​the connector structure. Several positive poles are spaced apart on the positive cover, while several negative poles are spaced apart on the negative cover. Separating the positive and negative poles increases the volume of the connector structure, further improving the current handling capacity of the cover.

[0009] Furthermore, the tab structure includes a positive tab and a negative tab, the positive tab and the negative tab are respectively located on both sides of the battery cell, the positive tab is connected to the positive electrode connecting piece, and the negative tab is connected to the negative electrode connecting piece.

[0010] The positive and negative electrode tabs are distributed on both sides of the battery cell to avoid pressure on the space under the cover plate caused by the two on the same side, which helps to increase the volume of the positive and negative electrode tabs, thereby improving the current capacity.

[0011] Furthermore, the connecting piece structure is provided with a slit along its length direction, and the tab structure extends into the slit to be connected to the connecting piece structure.

[0012] The tab structure is connected to the connecting piece structure through a gap, which helps to improve the stability of the connection between the two on the one hand, and on the other hand, both sides of the tab structure can contact the connecting piece structure, thereby increasing the flow area and improving the flow efficiency.

[0013] Furthermore, the positive electrode cover plate and the negative electrode cover plate are respectively located on opposite sides of the shell.

[0014] The positive and negative electrode covers are located on opposite sides of the shell so that the distance between them can be as large as possible, thereby facilitating the arrangement of the connecting piece structure, ensuring the volume of the connecting piece structure, and also facilitating the lead-out of the positive and negative electrode tabs of the battery cell.

[0015] Furthermore, the positive electrode cover plate is provided with a first liquid injection port, and the negative electrode cover plate is provided with a second liquid injection port. When the first liquid injection port is used for liquid injection, the second liquid injection port is used for vacuuming; or, when the first liquid injection port is used for vacuuming, the second liquid injection port is used for liquid injection.

[0016] The first liquid injection port and the second liquid injection port exist at the same time, so that vacuuming can be performed while liquid is being injected into the lithium battery, thereby improving the liquid injection efficiency.

[0017] Furthermore, the positive electrode cover plate is provided with two first explosion-proof valves, which are respectively located at both ends of the length direction of the positive electrode cover plate; the negative electrode cover plate is provided with two second explosion-proof valves, which are respectively located at both ends of the length direction of the negative electrode cover plate.

[0018] The first explosion-proof valve and the second explosion-proof valve both play the role of instantly releasing the gas inside the lithium battery, which can prevent the battery from exploding and improve the explosion-proof performance of the cover structure.

[0019] Furthermore, a plastic washer is provided at the bottom of the cover structure, and the position of the plastic washer corresponds to the position of the pole structure.

[0020] The plastic gasket can increase the insulation performance of the cover structure at the pole structure position and increase the safety of the lithium battery.

[0021] Furthermore, the plastic gasket is a rectangular structure with arc chamfers.

[0022] The plastic gasket with a rectangular structure and arc chamfers is convenient for assembling the cover structure, and the arc chamfers are also beneficial for improving the structural strength of the corners of the plastic gasket.

[0023] The utility model also provides a cover plate structure, which is the above-mentioned cover plate structure, including a positive electrode cover plate and a negative electrode cover plate.

[0024] Compared with the existing known technologies, the technical solution provided by the present invention has the following beneficial effects:

[0025] (1) The utility model discloses a lithium ion battery, sets up the same polarity of the pole post of a plurality of interval arrangement on the cover plate structure, and the connecting piece structure straddles a plurality of pole posts and connects each pole post, and the tab structure of electric core corresponds with the span of connecting piece structure and is connected, and the length of connecting piece structure and tab structure is longer than the prior art design, so the welding length and welding area of connecting piece structure and tab structure are larger, the overcurrent capacity of cover plate structure is improved, the battery heating is alleviated, and the battery explosion accident is reduced.

[0026] Obviously, the elements or features described in the above single embodiment can be used alone or in combination in other embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0027] In the drawings, the dimensions and proportions do not represent the actual product size and proportion. The drawings are merely illustrative, and some unnecessary elements or features are omitted for clarity.

[0028] Figure 1 It is the structure schematic diagram of electric core and cover plate structure into the shell in the utility model embodiment;

[0029] Figure 2 It is the connection structure schematic diagram of cover plate structure and electric core (one) in the utility model embodiment;

[0030] Figure 3 It is the connection structure schematic diagram of cover plate structure and electric core (two) in the utility model embodiment;

[0031] Figure 4 It is the structure schematic diagram of positive cover plate in the utility model embodiment;

[0032] Figure 5 It is the structure schematic diagram of negative cover plate in the utility model embodiment.

[0033] BRIEF DESCRIPTION OF DRAWINGS

[0034] 100, electric core;110, positive tab;120, negative tab;200, positive cover plate;210, positive pole;220, positive connecting piece;230, first liquid injection port;240, first explosion-proof valve;300, negative cover plate;310, negative pole;320, negative connecting piece;330, second liquid injection port;340, second explosion-proof valve;400, shell. DETAILED DESCRIPTION

[0035] Next, the utility model will be described in detail with reference to the drawings. What is described here is only according to the preferred embodiment of the utility model, and other ways that can realize the utility model can be thought of on the basis of the preferred embodiment by those skilled in the art, and other ways also fall within the scope of the utility model.

[0036] Example

[0037] In the prior art, the positive electrode column 210 and the negative electrode column 310 are centrally arranged on the battery cover, and the battery cell 100 is connected to the positive electrode column 210 and the negative electrode column 310 respectively through the positive electrode connecting piece 220 and the negative electrode connecting piece 320. The positive electrode connecting piece 220 and the negative electrode connecting piece 320 are all concentrated under the same battery cover, and the space under the battery cover is limited. The positive electrode connecting piece 220 and the negative electrode connecting piece 320 share the same space, resulting in the volume of the positive electrode connecting piece 220 and the negative electrode connecting piece 320 being limited and the structure of the connection part with the battery cell 100 being limited, resulting in poor current flow capacity of the cover and severe heat generation.

[0038] To solve the above problems, refer to Figures 1-5 This embodiment provides a lithium-ion battery, including a battery cell 100, a cover plate structure, and a shell 400. The cover plate structure and the shell 400 form a closed space. The battery cell 100 is arranged in the closed space and is electrically connected to the cover plate structure. The cover plate structure includes a plurality of pole structures of the same polarity arranged at intervals. The pole structures are connected by connecting plate structures of corresponding polarities. The connecting plate structure spans across multiple pole structures. The battery cell 100 is provided with a tab structure corresponding to the polarity of the connecting plate structure. The span of the tab structure corresponds to the span of the connecting plate structure, and the tab structure is connected to the connecting plate structure. The connecting plate structure spans across multiple pole structures and is connected to the pole structures. The length and area of ​​the connecting plate are relatively larger. In addition, the battery cell 100 is also provided with a tab structure of corresponding span. When the tab structure is connected to the connecting plate structure, it has a larger connection area, thereby improving the overcurrent capacity of the cover plate structure and alleviating battery heating. Moreover, the cover structure is provided with poles of the same polarity, which means that the positive cover structure and the negative cover structure are provided separately, providing more space to accommodate the tab structure and the connecting piece structure, greatly improving the current carrying capacity of the cover structure.

[0039] Specifically, such as Figure 1 、 Figure 4 and Figure 5 As shown, the cover plate structure includes a positive cover plate 200 and a negative cover plate 300. The positive cover plate 200 and the negative cover plate 300 are respectively located on both sides of the housing 400, which increases the space under the cover plate structure, which is conducive to increasing the area of ​​the corresponding connecting plate structure, thereby improving the flow capacity of the connecting plate structure. The positive cover plate 200 is provided with a number of positive poles 210 at intervals, and the negative cover plate 300 is provided with a number of negative poles 310 at intervals; the positive poles 210 are connected by positive connecting plates 220, and the negative poles 310 are connected by negative connecting plates 320. The separate arrangement of the positive poles 210 and the negative poles 310 is conducive to increasing the volume of the connecting plate structure, thereby further improving the flow capacity of the cover plate structure.

[0040] It is understandable that ifFigure 2 and Figure 3 As shown, the tab structure includes a positive tab 110 and a negative tab 120. The positive tab 110 and the negative tab 120 are respectively located on both sides of the battery cell 100. The positive tab 110 is connected to the positive electrode connecting tab 220, and the negative tab 120 is connected to the negative electrode connecting tab 320. The positive tab 110 and the negative tab 120 are distributed on both sides of the battery cell 100 to avoid pressure on the space under the cover plate on the same side caused by the two tabs on the same side, which helps to increase the volume of the positive tab 110 and the negative tab 120, thereby improving the current capacity.

[0041] In some embodiments of the present application, the connecting sheet structure is provided with a gap along its length, and the tab structure extends into the gap to connect with the connecting sheet structure. On the one hand, this helps to improve the stability of the connection between the two, and on the other hand, both sides of the tab structure can contact the connecting sheet structure, thereby increasing the flow area and improving the flow efficiency. Figure 2 As shown, the positive electrode tab 110 is connected to the gap of the positive electrode connecting sheet 220 , and the negative electrode tab 120 is connected to the gap of the negative electrode connecting sheet 320 .

[0042] Furthermore, Figure 1 、 Figure 2 and Figure 3 As shown, the positive electrode cover plate 200 and the negative electrode cover plate 300 are respectively located on opposite sides of the shell 400, so that the distance between the positive electrode cover plate 200 and the negative electrode cover plate 300 can be expanded as much as possible, thereby facilitating the arrangement of the connecting piece structure, ensuring the volume of the connecting piece structure, and also facilitating the lead-out of the positive electrode tab 110 and the negative electrode tab 120 of the battery cell 100.

[0043] In some embodiments of the present application, Figure 4 and Figure 5 As shown, the positive electrode cover plate 200 is provided with a first liquid injection port 230, and the negative electrode cover plate 300 is provided with a second liquid injection port 330. The first liquid injection port 230 is used for liquid injection while the second liquid injection port 330 is used for vacuuming; or, the first liquid injection port 230 is used for vacuuming while the second liquid injection port 330 is used for liquid injection. The first liquid injection port 230 and the second liquid injection port 330 exist at the same time. During liquid injection, one liquid injection port can be used to inject liquid while the other liquid injection port is used for vacuuming, which can improve liquid injection efficiency. It can be understood that the structure of the first liquid injection port 230 and the second liquid injection port 330 is the same as the liquid injection port structure in the prior art.

[0044] In some embodiments of the present application, Figure 4 and Figure 5As shown, the positive electrode cover plate 200 is equipped with two first explosion-proof valves 240, one at each end of the positive electrode cover plate 200's lengthwise direction; the negative electrode cover plate 300 is equipped with two second explosion-proof valves 340, one at each end of the negative electrode cover plate 300's lengthwise direction. Both the first explosion-proof valve 240 and the second explosion-proof valve 340 instantly release the gas inside the lithium battery, preventing the battery from exploding and improving the explosion-proof performance of the cover plate structure. Moreover, compared to the prior art, the number of first explosion-proof valves 240 and second explosion-proof valves 340 is greater, resulting in a better explosion-proof effect.

[0045] In some embodiments of the present application, a plastic washer is provided at the bottom of the cover structure, corresponding to the position of the pole structure. The plastic washer can enhance the insulation performance of the cover structure at the position of the pole structure, thereby increasing the safety of the lithium battery. Furthermore, the plastic washer is a rectangular structure with rounded chamfers, which facilitates the assembly of the cover structure. The rounded chamfers also help to improve the structural strength of the plastic washer corners.

[0046] It should be noted that in the above-described lithium battery structure, the positive electrode posts 210 are made of aluminum, and the negative electrode posts 310 are made of copper with a nickel surface. The positive electrode connector 220 is made of aluminum, and the negative electrode connector 320 is made of copper. The battery cell 100 has a wound core structure.

[0047] In another aspect of the present application, a cover plate structure is provided, which is the above-mentioned cover plate structure and includes a positive electrode cover plate 200 and a negative electrode cover plate 300 .

[0048] In the description of this utility model, it should be noted that the terms "front," "back," "left," "right," "up," "down," "top," "bottom," "inside," and "outside" and the like, indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0050] The scope of protection of the utility model is only limited by the claims. Thanks to the teaching of the utility model, the person skilled in the art can easily recognize that the alternative structure of the disclosed structure of the utility model can be used as a feasible alternative implementation mode, and the disclosed implementation mode of the utility model can be combined to produce a new implementation mode, which also falls within the scope of the appended claims.

Claims

1. A lithium-ion battery comprising a battery cell (100), a cover plate structure and a housing (400), wherein the cover plate structure and the housing (400) form a closed space, and the battery cell (100) is arranged in the closed space and electrically connected to the cover plate structure; It is characterized in that The cover plate structure comprises a plurality of pole structures of the same polarity arranged at intervals, the pole structures being connected via connecting piece structures of corresponding polarities, the connecting piece structures being arranged across the plurality of pole structures; the battery cell (100) is provided with a tab structure corresponding to the polarity of the connecting piece structure, the span of the tab structure corresponding to the span of the connecting piece structure, and the tab structure being connected to the connecting piece structure.

2. A lithium-ion battery according to claim 1, characterized in that: The cover plate structure comprises a positive cover plate (200) and a negative cover plate (300), wherein the positive cover plate (200) and the negative cover plate (300) are respectively located on both sides of a housing (400); the positive cover plate (200) is provided with a plurality of positive poles (210) at intervals, and the negative cover plate (300) is provided with a plurality of negative poles (310) at intervals; the plurality of positive poles (210) are connected via a positive connecting piece (220), and the plurality of negative poles (310) are connected via a negative connecting piece (320).

3. A lithium-ion battery according to claim 2, characterized in that: The tab structure comprises a positive tab (110) and a negative tab (120), wherein the positive tab (110) and the negative tab (120) are respectively located on both sides of the battery cell (100), the positive tab (110) is connected to the positive electrode connecting piece (220), and the negative tab (120) is connected to the negative electrode connecting piece (320).

4. A lithium-ion battery according to claim 1, characterized in that: The connecting piece structure is provided with a gap along its length direction, and the tab structure extends into the gap and is connected to the connecting piece structure.

5. A lithium-ion battery according to claim 2, characterized in that: The positive electrode cover plate (200) and the negative electrode cover plate (300) are respectively located on opposite sides of the housing (400).

6. A lithium-ion battery according to claim 2, characterized in that: The positive electrode cover plate (200) is provided with a first liquid injection port (230), and the negative electrode cover plate (300) is provided with a second liquid injection port (330). When the first liquid injection port (230) is used for liquid injection, the second liquid injection port (330) is used for vacuuming; or, when the first liquid injection port (230) is used for vacuuming, the second liquid injection port (330) is used for liquid injection.

7. A lithium-ion battery according to claim 2, characterized in that: The positive electrode cover plate (200) is provided with two first explosion-proof valves (240), and the two first explosion-proof valves (240) are respectively located at both ends of the length direction of the positive electrode cover plate (200); the negative electrode cover plate (300) is provided with two second explosion-proof valves (340), and the two second explosion-proof valves (340) are respectively located at both ends of the length direction of the negative electrode cover plate (300).

8. The lithium-ion battery according to claim 1, characterized in that: A plastic washer is provided at the bottom of the cover structure, and the position of the plastic washer corresponds to the position of the pole structure.

9. A lithium-ion battery according to claim 8, characterized in that: The plastic gasket is a rectangular structure with arc chamfers.

10. A cover plate structure, characterized in that: The cover plate structure according to any one of claims 1 to 9 comprises a positive electrode cover plate (200) and a negative electrode cover plate (300).

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