Battery cell structure

Abstract

The utility model relates to the technical field of batteries, in particular to a battery cell structure, which comprises a top cover, a battery cell package and a flexible insulating part, a tab protection area, a battery cell package connecting area and a laser welding protection area are arranged on the flexible insulating part, the tab protection area is arranged on the laser welding protection area, and the battery cell package connecting area is arranged on the battery cell package connecting area. The tab protection area is of a groove-shaped structure, and the inner side of the groove is used for accommodating a tab of the battery cell package; one end of the battery cell cladding connection area is arranged on the tab protection area, and the other end of the battery cell cladding connection area is fixed on the battery cell cladding; the laser welding protection area is fixed on the top cover and is used for covering an adapter plate of the top cover; according to the battery cell structure provided by the utility model, the flexible insulating part is only used for covering the tabs, so that the tabs cannot be damaged by pulling, and the problem that the tabs are easy to tear due to the insulating protection structure of the existing tabs is solved.

Description

Technical Field

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

[0002] In the production of square batteries, to enable current conduction between the battery cells inside the battery casing and the external environment, the cell tabs are typically welded to the terminals via adapter plates or directly. The welded points and tabs are then insulated using an adhesive bonding process. For example, the utility model disclosed in publication number CN213905439U describes a square lithium-ion battery core structure, in which the tabs are insulated using the aforementioned adhesive bonding method.

[0003] During the welding process, because the tabs are multi-layered stacked structures, the outermost tab, in the direction perpendicular to the adapter plate or terminal post, will have a certain radius (R-angle) when folded. Due to stress concentration at this folded R-angle, during the 90° folding of the cell after adhesive application, the tape pulls on the outermost tab with the most concentrated stress, easily causing it to tear. This affects the yield rate in the production process and the safety of the battery. Utility Model Content

[0004] In view of this, the present invention proposes a cell structure in which the flexible insulating component is only used to cover the tabs, so it will not cause pulling damage to the tabs. This solves the problem that the existing tab insulation protection structure is prone to causing the tabs to tear, which is conducive to improving the yield in the production process of square batteries and the subsequent battery safety.

[0005] The technical solution of this utility model is implemented as follows:

[0006] This utility model provides a battery cell structure, including a top cover and a battery cell pack, wherein the electrode tabs of the battery cell pack are fixed on the adapter plate of the top cover;

[0007] It also includes flexible insulation components, among which,

[0008] The flexible insulating component is provided with a tab protection zone, a cell-packing connection zone, and a laser welding protection zone, wherein...

[0009] The electrode protection zone is located on the laser welding protection zone. The electrode protection zone is a groove-shaped structure, and the inner side of the groove is used to accommodate the electrode of the battery cell package.

[0010] One end of the cell core pack connection area is located on the tab protection zone, and the other end is fixed on the cell core pack;

[0011] The laser welding protection zone is fixed to the top cover and is used to cover the adapter plate of the top cover.

[0012] Based on the above technical solutions, preferably, the cell core pack connection area is fixed on the large surface of the cell core pack.

[0013] Based on the above technical solutions, preferably, the electrode protection zone and the cell core packing connection zone are respectively mirror-imaged on the flexible insulating component.

[0014] Based on the above technical solutions, preferably, the laser welding protection zone is fixed to the top cover by a fixing adhesive column.

[0015] Based on the above technical solutions, preferably, a fixed point is provided on the laser welding protection zone, wherein,

[0016] The fixing point is attached and fixed to the fixing adhesive column.

[0017] Based on the above technical solutions, preferably, both the fixing point and the fixing adhesive column are elliptical.

[0018] Based on the above technical solutions, preferably, the top cover includes a top cover plate and a lower plastic layer, wherein,

[0019] The lower plastic is disposed on the top cover plate, and the lower plastic has two U-shaped insulating positioning grooves with opposite openings;

[0020] The inner side of the insulating component positioning groove is used to set the flexible insulating component and the fixing adhesive column.

[0021] Based on the above technical solutions, preferably, the top cover further includes a positive lower electrode post and a negative lower electrode post, wherein,

[0022] Both the positive lower electrode post and the negative lower electrode post are fixed to the top cover plate;

[0023] One end of the positive lower electrode post penetrates the lower plastic and extends to the inside of one of the insulating component positioning grooves;

[0024] One end of the negative electrode lower post penetrates the lower plastic and extends to the inside of another insulating component positioning groove.

[0025] Based on the above technical solutions, preferably, the adapter plate of the top cover includes a negative adapter plate and a positive adapter plate, and the electrode tabs of the battery cell package include positive electrode tabs and negative electrode tabs, wherein,

[0026] The positive electrode adapter piece is fixed on one end of the lower positive electrode post that extends into the positioning groove of the insulating component, and the positive electrode tab is fixed on one end of the positive electrode adapter piece that is away from the lower positive electrode post.

[0027] The negative electrode adapter piece is fixed on one end of the negative electrode lower post that extends into the positioning groove of the insulating component, and the negative electrode tab is fixed on the end of the negative electrode adapter piece that is away from the negative electrode lower post.

[0028] Based on the above technical solutions, preferably, an explosion-proof valve is provided in the middle of the lower plastic section, and an injection hole is provided on one side of the lower plastic section.

[0029] The insulating component positioning grooves are symmetrically arranged on both sides of the plastic under the explosion-proof valve;

[0030] The injection hole is located between the lower plastic part of the explosion-proof valve and the lower negative electrode post.

[0031] The battery cell structure of this utility model has the following advantages over the prior art:

[0032] (1) By setting the tab protection zone as a groove structure, the flexible insulating part can be used only to cover the tab, so it will not pull the tab and thus it is not easy to cause the tab to tear, which is conducive to improving the yield of the square battery production process and the subsequent battery safety.

[0033] (2) By setting up the positioning groove of the insulating component, the flexible insulating component can be accurately positioned during assembly, and the fixed glue column can be accurately positioned during assembly.

[0034] (3) By setting fixed points, the hot melt points on the flexible insulation parts are marked, which effectively ensures the accurate positioning of the fixed glue pillars during assembly. At the same time, by setting fixed glue pillars, the hot melt fixing of the flexible insulation parts is facilitated, and the assembly efficiency is improved. Attached Figure Description

[0035] 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.

[0036] Figure 1 This is a perspective view of a battery cell structure according to the present invention;

[0037] Figure 2 This is an exploded view of a battery cell structure according to the present invention;

[0038] Figure 3 This is a three-dimensional view of a flexible insulating component;

[0039] Figure 4 This is a 3D view of the top cover;

[0040] Figure 5 This is a comparative diagram of a square battery cell assembly structure;

[0041] Figure 6 An exploded view of a symmetrical square battery cell assembly;

[0042] In the diagram: 1. Top cover; 2. Negative electrode adapter; 3. Positive electrode adapter; 4. Battery cell core pack; 5. Positive electrode tab; 6. Negative electrode tab; 7. Flexible insulation component; 8. Adhesive tape; 9. Lower layer adapter tape; 10. Tab tape; 11. Welding area tape; 101. Top cover plate; 102. Lower plastic; 103. Fixing post; 104. Lower positive electrode post; 105. Lower plastic of explosion-proof valve; 106. Injection hole; 107. Lower negative electrode post; 401. Large surface; 701. Fixing point; 702. Tab protection zone; 703. Battery cell core pack connection area; 704. Laser welding protection zone; 1021. Insulation component positioning groove. Detailed Implementation

[0043] The technical solutions of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0044] like Figure 1-4 As shown, a battery cell structure of this utility model includes a top cover 1, a battery cell core package 4, and a flexible insulating component 7.

[0045] In this structure, the tabs of the battery cell pack 4 are fixed to the adapter plate of the top cover 1. The flexible insulating component 7 is provided with a tab protection zone 702, a battery cell pack connection area 703, and a laser welding protection zone 704. The tab protection zone 702 is located on the laser welding protection zone 704 and has a groove-shaped structure, with its inner side used to accommodate the tabs of the battery cell pack 4. One end of the battery cell pack connection area 703 is located on the tab protection zone 702, and the other end is fixed to the battery cell pack 4. The laser welding protection zone 704 is fixed to the top cover 1 and is used to cover the adapter plate of the top cover 1. In this structure, the groove-shaped tab protection zone 702 is only used to cover the tabs, so it will not cause pulling on the tabs, thus reducing the risk of tab tearing. This is beneficial to improving the yield rate in the production process of square batteries and the subsequent battery safety.

[0046] In the above-mentioned insulating protection structure, the top cover 1 includes a top cover plate 101, a lower plastic 102, a fixing post 103, a positive lower electrode post 104, a plastic 105 under the explosion-proof valve, an injection hole 106, and a negative lower electrode post 107.

[0047] The lower plastic 102 is mounted on the top cover plate 101. The lower plastic 102 has two U-shaped insulating positioning grooves 1021 with opposite openings. The positive lower electrode post 104 and the negative lower electrode post 107 are both fixed to the top cover plate 101. One end of the positive lower electrode post 104 penetrates the lower plastic 102 and extends to the inside of one of the insulating positioning grooves 1021. One end of the negative lower electrode post 107 penetrates the lower plastic 102 and extends to the inside of the other insulating positioning groove 1021. A positive adapter piece 3 is also included. The positive electrode tab 5 is fixed on the end of the positive electrode lower post 104 that extends into the inner side of the insulating component positioning groove 1021; the negative electrode tab 2 is fixed on the end of the negative electrode adapter 3 that is away from the positive electrode lower post 104; the negative electrode adapter 2 is fixed on the end of the negative electrode lower post 107 that extends into the inner side of the insulating component positioning groove 1021; and the negative electrode tab 6 is fixed on the end of the negative electrode adapter 2 that is away from the negative electrode lower post 107. A flexible insulating component 7 is provided in each insulating component positioning groove 1021 to cover the components inside the insulating component positioning groove 1021.

[0048] The lower plastic part 105 of the explosion-proof valve is located in the middle of the lower plastic part 102, and the positive lower electrode post 104 and the negative lower electrode post 107 are separated by the lower plastic part 105. A liquid injection hole 106 is provided on one side of the lower plastic part 102, and the liquid injection hole 106 is located between the lower plastic part 105 and the negative lower electrode post 107.

[0049] Fixing posts 103 are respectively provided on the shoulder of the insulating component positioning groove 1021, the lower positive electrode post 104, the lower plastic part 105 of the explosion-proof valve, and the injection hole 106. The fixing posts 103 are integrally injection molded with the insulating component positioning groove 1021, the lower plastic part 102, and the lower plastic part 105 of the explosion-proof valve. The fixing posts 103 are set close to the shoulder of the insulating component positioning groove 1021, which can ensure a more secure connection between the fixing posts 103 and the insulating component positioning groove 1021.

[0050] Furthermore, the length of the fixing column 103 is 4-7mm and the width is 2-4mm. The length and width of the fixing column 103 placed in different positions are exactly the same. The material of the entire lower plastic 102 is one or more of polypropylene PP, polycarbonate PC, polystyrene PS, polyphenylene ether PPE, and polyphenylene sulfide PPS.

[0051] Furthermore, the number of fixing posts 103 near the shoulder of the insulating component positioning groove 1021 is 2 to 4, preferably 3.

[0052] In a specific embodiment, a flexible insulating element 7 is provided at both the positive and negative tabs. The two flexible insulating elements 7 are symmetrically arranged on both sides of the plastic 105 under the explosion-proof valve and are consistent in size. The flexible insulating element 7 is formed by stretching a polymer film material and has the characteristics of being soft and insulating. It can achieve complete coverage and insulation protection for different welding heights and connection parts, such as the laser welding area of ​​the adapter plate, the ultrasonic welding area of ​​the tab, and the root of the tab.

[0053] When the flexible insulating component 7 is stretched, its main body consists of a fixed point 701, a laser welding protection zone 704, a tab protection zone 702, and a cell-packing connection zone 703. Due to the structure of the flexible insulating component 7, after laser welding is completed during the assembly process, the laser welding protection zone 704 and the cell-packing connection zone 703 can be directly grasped by a robotic arm for assembly. This results in a high degree of compatibility with the production line and effectively improves the efficiency of the production process.

[0054] Two to four fixing points 701 are provided on the flexible insulating component 7 at positions away from the tab and corresponding to the fixing posts 103, with three being preferred. Additionally, two fixing points 701 are also provided near the tab. Correspondingly, two fixing posts 103 are also provided at corresponding positions on the lower plastic component 102. The fixing points 701 and the fixing posts 103 are positioned and shaped to match, and the length and width of the fixing points 701 are consistent with the length and width of the fixing posts 103. During assembly, the two are fixed by heat fusion bonding.

[0055] Furthermore, the laser welding protection zone 704 is a planar structure, which is used to protect the welding area between the lower positive electrode post 104 and the positive electrode adapter 3. In terms of spatial position, the laser welding protection zone 704 is parallel to the lower positive electrode post 104 and the positive electrode adapter 3.

[0056] Furthermore, the positive electrode tab 5 has a multi-layered, gathered structure and has a certain thickness during welding. Therefore, the tab protection zone 702 has a groove-shaped structure, the shape of which matches the shape of the stacked positive electrode tab 5. During welding, the positive electrode tab 5 is hidden in the groove to achieve tab protection.

[0057] Furthermore, the core-pack connection area 703 is fixed to the large surface 401 of the core-pack 4 using adhesive tape 8, or an adhesive layer is applied to the core-pack connection area 703 directly opposite the large surface 401 of the core-pack 4, allowing for direct and secure connection between the adhesive layer and the large surface 401 of the core-pack 4, thus improving the stability of the flexible insulation component 7 after installation. The core-pack 4 is a rectangular core-pack, such as... Figure 1 As shown, the square face in the thickness direction is the large face 401.

[0058] In a specific implementation, the positive electrode tab 5 and negative electrode tab 6 on the battery cell core package 4 are connected to the positive electrode adapter 3 and negative electrode adapter 2 corresponding to the polarity, respectively. The positive electrode adapter 3 and negative electrode adapter 2 are connected to the positive electrode lower post 104 and negative electrode lower post 107 corresponding to the polarity on the top cover 1, respectively, thereby realizing the conduction of positive and negative electrodes on the core package with external current. The flexible insulating member 7 is connected and fixed to the top cover 1 through the fixing post 103, and is connected and fixed to the battery cell core package 4 through the battery cell core package connection area 703.

[0059] Furthermore, the positive electrode tab 5 and the positive electrode adapter 3 are made of aluminum, while the negative electrode tab 6 and the negative electrode adapter 2 are made of copper. The positive electrode tab 5 is made of multiple layers of aluminum foil that are gathered together and then connected to the positive electrode adapter 3 by ultrasonic welding. The negative electrode tab 6 is made of multiple layers of copper foil that are gathered together and then connected to the negative electrode adapter 2 by ultrasonic welding.

[0060] Furthermore, the positive electrode adapter 3 and the negative electrode adapter 2 are connected to the positive electrode lower terminal 104 and the negative electrode lower terminal 107 respectively by laser welding.

[0061] Furthermore, the flexible insulating component 7 is made of one or more of polyethylene terephthalate (PET), polypropylene (PP), and polycarbonate (PC). After the flexible insulating component 7 is formed, two electrode protection zones 702 and two cell core package connection zones 703 are mirror-imagely arranged on the flexible insulating component 7. The two electrode protection zones 702 are used for insulation protection of two electrodes of the same polarity, and each electrode protection zone 702 is provided with a corresponding cell core package connection zone 703. The two cell core package connection zones 703 are used to connect one cell core package 4.

[0062] Furthermore, fixing point 701 is a heat-melt marking point with an elliptical shape. When installing the flexible insulating component 7, fixing point 701 is placed corresponding to the fixing adhesive post 103. Through this heat-melt marking point, the flexible insulating component 7 can be accurately marked and positioned, enabling rapid heat-melt fixing and improving the fixing effect of the flexible insulating component 7.

[0063] To highlight the technical effects of this utility model, such as Figure 5-6 As shown, this utility model provides a comparative structure, which is a conventional battery structure. It uses adhesive bonding to achieve insulation and protection of the tabs. The assembly process is as follows:

[0064] After the battery cell core pack 4 is paired, the positive electrode tab 5 and the negative electrode tab 6 are ultrasonically welded to the positive electrode adapter 3 and the negative electrode adapter 2, respectively.

[0065] After ultrasonic welding, the tab tape 10 is pasted by a mechanical adhesive applicator. Further, the lower adapter tape 9 is pasted to insulate the part of the adapter area and the tab area near the lower pole post. One end of the lower adapter tape 9 is fixed on the adapter and the other end is fixed on the battery cell core package 4.

[0066] After the adhesive is applied, the positive electrode adapter 3 or the negative electrode adapter 2 is laser welded to the positive electrode lower post 104 and the negative electrode lower post 107 on the top cover 1, respectively, to ensure that the battery cell core package 4 forms a current conduction path with the outside of the battery cell through the tabs and adapters at the post. After welding, the welding area tape 11 is pasted to provide insulation protection for the laser welding area. Then, the battery cell assembly is completed by the following processes: core bonding, Mylar film wrapping, casing insertion, and top cover welding.

[0067] Because the tabs will form a certain radius (R-angle) during the welding process, and there will be a certain stress concentration at the R-angle, the downward pressing action of the adhesive applicator can easily cause the tabs in the stress concentration area of ​​the R-angle to tear. At the same time, after the battery cells are paired and welded, they need to be folded 90° during the core assembly process. During the folding process, the adhesive layer of the tape will pull on the outermost R-angle area where the stress is more concentrated, which can also easily cause the tabs to tear.

[0068] In comparison, this utility model optimizes the insulation protection structure and uses flexible insulating parts 7 to achieve insulation protection. This eliminates the need for mechanical pressing and adhesive application, avoids damage to the stress concentration area at the R-corner that could cause tab tearing, improves the tab tearing situation at the R-corner, increases the battery yield during production, and enhances the overall quality and safety of the battery.

[0069] The assembly sequence of a battery cell structure according to this utility model is as follows:

[0070] First, ultrasonic welding is performed between the tab and the adapter plate. Then, adhesive insulation is applied between the adapter plate and the battery cell core pack 4 on the other side of the battery cell core pack 4, near the lower electrode post. Next, laser welding is performed between the adapter plate and the lower electrode post. After welding, the flexible insulating part 7 is heat-fused onto the top cover 1 for fixation. During the assembly process, the flexible insulating part 7 can be placed on the top cover 1 and the tab by using a robotic arm to grasp the laser welding protection zone 704 and the battery cell core pack connection area 703.

[0071] The above are merely preferred embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A battery cell structure, comprising a top cover (1) and a battery cell package (4), wherein, The electrode tabs of the battery cell core package (4) are fixed on the adapter plate of the top cover (1); Its characteristic is that it further includes a flexible insulating element (7), wherein, The flexible insulating component (7) is provided with a tab protection zone (702), a cell core-pack connection zone (703), and a laser welding protection zone (704), wherein, The electrode protection zone (702) is located on the laser welding protection zone (704). The electrode protection zone (702) is a groove-shaped structure, and the inner side of the groove is used to accommodate the electrode of the battery cell core package (4). One end of the battery cell core pack connection area (703) is located on the electrode protection zone (702), and the other end is fixed on the battery cell core pack (4); The laser welding protection zone (704) is fixed on the top cover (1) and is used to cover the adapter plate of the top cover (1).

2. The cell structure as described in claim 1, characterized in that: The cell core pack connection area (703) is fixed on the large surface (401) of the cell core pack (4).

3. The cell structure as described in claim 1, characterized in that: The electrode protection zone (702) and the cell core packing connection area (703) are respectively mirrored on the flexible insulating member (7).

4. The cell structure as described in claim 1, characterized in that: The laser welding protection zone (704) is fixed to the top cover (1) by a fixing adhesive column (103).

5. A cell structure as described in claim 4, characterized in that: Fixed points (701) are provided on the laser welding protection zone (704), wherein, The fixing point (701) is bonded and fixed to the fixing adhesive column (103).

6. A cell structure as described in claim 5, characterized in that: Both the fixing point (701) and the fixing column (103) are elliptical.

7. A cell structure as described in claim 5, characterized in that: The top cover (1) includes a top cover plate (101) and a lower plastic part (102), wherein, The lower plastic (102) is disposed on the top cover plate (101), and the lower plastic (102) has two U-shaped insulating positioning grooves (1021) with opposite openings; The inner side of the insulating component positioning groove (1021) is used to set the flexible insulating component (7) and the fixing adhesive column (103).

8. A cell structure as described in claim 7, characterized in that: The top cover (1) further includes a positive lower electrode post (104) and a negative lower electrode post (107), wherein, Both the positive lower electrode post (104) and the negative lower electrode post (107) are fixed on the top cover plate (101); One end of the positive electrode lower post (104) passes through the lower plastic (102) and extends to the inside of one of the insulating component positioning grooves (1021); One end of the negative electrode lower post (107) passes through the lower plastic (102) and extends to the inside of another insulating element positioning groove (1021).

9. A cell structure as described in claim 8, characterized in that: The top cover (1) has a connecting piece including a negative connecting piece (2) and a positive connecting piece (3), and the battery cell core package (4) has a tab including a positive tab (5) and a negative tab (6), wherein, The positive electrode adapter (3) is fixed on one end of the positive electrode lower pole (104) that extends into the inner side of the insulating positioning groove (1021), and the positive electrode tab (5) is fixed on one end of the positive electrode adapter (3) away from the positive electrode lower pole (104); The negative electrode adapter (2) is fixed on one end of the negative electrode lower pole (107) that extends into the inner side of the insulating positioning groove (1021), and the negative electrode tab (6) is fixed on one end of the negative electrode adapter (2) away from the negative electrode lower pole (107).

10. A cell structure as described in claim 8, characterized in that: An explosion-proof valve lower plastic (105) is provided in the middle of the lower plastic (102), and an injection hole (106) is provided on one side of the lower plastic (102). The insulating component positioning groove (1021) is symmetrically arranged on both sides of the plastic (105) under the explosion-proof valve; The injection hole (106) is located between the lower plastic part (105) of the explosion-proof valve and the lower negative electrode post (107).

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