Cover plate structure and battery cell

Abstract

This utility model relates to the field of energy storage equipment technology, and in particular to a cover plate structure and a battery cell. The cover plate structure includes a lower plastic sheet, with protrusions at both ends along its length. Each protrusion abuts against the end face of an electrode assembly. The apex of each protrusion is designed with a notched corner structure, corresponding to the corner of the electrode assembly. The edges of the protrusions facing the electrode assembly are chamfered, corresponding to the edges of the electrode assembly facing the lower plastic sheet. By providing chamfered and notched corner structures at the edges and corners of the lower plastic sheet corresponding to the electrode assembly's end face, damage to the edges and corners of the electrode assembly can be avoided, improving the battery cell's manufacturing yield and safety performance. The battery cell includes an electrode assembly, a housing body, and the aforementioned cover plate structure. The cover plate structure is sealed at an opening at one end of the housing body along its length, with the electrode assembly located within the housing body.

Description

Technical Field

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

[0002] In existing technologies, blade batteries are generally designed with positive and negative tabs on both sides, and the tabs are welded to the output end of the cover plate to ensure current conduction. The lower plastic of the cover plate is attached to the inside of the cover plate. The protrusions of the lower plastic facing the electrode assembly are planar structures that fit completely with the electrode assembly. During the process of the cover plate being installed in the casing, the lower plastic presses against the electrode assembly. When the finished battery cell is subjected to vibration, impact, or other environments, and the electrode assembly moves inside the casing, the interaction force between the lower plastic of the cover plate and the electrode assembly will also increase. Under these circumstances, the edges and corners of the electrode assembly are often damaged by the lower plastic, which in turn affects the process yield and safety performance of the battery cell. Utility Model Content

[0003] One objective of this invention is to provide a cover structure that can prevent the edges and corners of the electrode assembly from being damaged by the lower plastic, thereby improving the process yield and safety performance of the battery cell.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A cover plate structure is provided, including a lower plastic, with protrusions at both ends along its length. Both protrusions are used to abut against the end face of an electrode assembly. The apex corners of the two protrusions are provided with notched corner structures, which correspond to the corners of the electrode assembly. The edges of the two protrusions facing the end face of the electrode assembly are provided with chamfered structures, which correspond to the edges of the end face of the electrode assembly facing the lower plastic.

[0006] Optionally, the maximum dimension 'a' of the notched structure along the length of the lower plastic material ranges from 3mm to 6mm.

[0007] And / or, the maximum dimension b of the notched structure along the width direction of the lower plastic is in the range of 3mm-6mm.

[0008] Optionally, the ratio of the dimension of the notched structure along the thickness direction of the lower plastic to the maximum thickness of the lower plastic ranges from 30% to 60%.

[0009] Optionally, the notched structure is a triangular prism.

[0010] Optionally, the end faces of the two protrusions facing the pole group each have two bevels, the two bevels respectively correspond to the two corners of the pole group, and the bevels have the chamfered structure.

[0011] Optionally, the maximum dimension c of the chamfer structure along the protrusion direction of the protrusion is in the range of 0.5mm-1.5mm.

[0012] Optionally, the lower plastic part is provided with a notched corner structure at each of the four corners corresponding to the electrode assembly;

[0013] And / or, the lower plastic has chamfered structures at all four edges corresponding to one end of the electrode assembly.

[0014] Optionally, the sides of the protrusions corresponding to the four corners of the pole group are all configured as curved surfaces.

[0015] Another objective of this invention is to provide a battery cell that can prevent the edges and corners of the electrode assembly from being damaged by the lower plastic, resulting in higher process yield and safety performance.

[0016] To achieve this objective, the present invention adopts the following technical solution:

[0017] A battery cell is provided, comprising an electrode assembly, a housing body, and the aforementioned cover plate structure, wherein the cover plate structure is sealed over an opening at one end of the housing body along its length, and the electrode assembly is located within the housing body.

[0018] Optionally, the compression of the pole group along the length of the shell body ranges from 3mm to 5mm.

[0019] The beneficial effects of this utility model are:

[0020] This utility model provides a cover plate structure, including a lower plastic sheet. Both ends of the lower plastic sheet along its length have protrusions, each protruding portion abutting against the end face of the electrode assembly. The apex of each protrusion is designed with a notched corner structure, corresponding to the corner of the electrode assembly. The edges of the two protrusions facing the end face of the electrode assembly are chamfered, corresponding to the edge of the electrode assembly facing the lower plastic sheet. By providing chamfered and notched corner structures at the edges and corners of the lower plastic sheet corresponding to the end face of the electrode assembly, damage to the edges and corners of the electrode assembly by the lower plastic sheet can be avoided. This ensures the structural integrity of the electrode assembly after casing, improves the cell manufacturing yield, and helps prevent damage to the edges and corners of the electrode assembly by the lower plastic sheet during use, thereby improving the safety performance of the cell.

[0021] This utility model also provides a battery cell, including an electrode assembly, a housing body, and the aforementioned cover plate structure. The cover plate structure is sealed over an opening at one end of the housing body along its length, and the electrode assembly is located inside the housing body. This battery cell can prevent the edges and corners of the electrode assembly from being damaged by the lower plastic, resulting in higher process yield and safety performance. Attached Figure Description

[0022] Figure 1 This is a partial structural schematic diagram of the battery cell provided in an embodiment of the present invention;

[0023] Figure 2 This is a first-view structural schematic diagram of the cover plate structure provided in this embodiment of the utility model;

[0024] Figure 3 This is a second-view structural schematic diagram of the cover plate structure provided in this embodiment of the utility model;

[0025] Figure 4 This is a third-view structural schematic diagram of the cover plate structure provided in this embodiment of the utility model;

[0026] Figure 5 This is a fourth-view structural schematic diagram of the cover plate structure provided in this embodiment of the utility model.

[0027] In the picture:

[0028] 1. Bottom plastic; 11. Protrusion; 111. Notched corner structure; 112. Chamfered structure; 113. Curved transition; 2. Top cover;

[0029] 100, Cover plate structure; 200, Electrode group; 201, Electrode tab; 300, Second cover plate; 400, End plate; 500, Negative output terminal; 600, Positive output terminal. Detailed Implementation

[0030] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this utility model are shown in the drawings, not all of them.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] In existing technologies, blade batteries are generally designed with positive and negative tabs on both sides, and the tabs are welded to the output end of the cover plate to ensure current conduction. The lower plastic of the cover plate is attached to the inside of the cover plate. The protrusions of the lower plastic facing the electrode assembly are planar structures that fit completely with the electrode assembly. During the process of the cover plate being installed in the casing, the lower plastic presses against the electrode assembly. When the finished battery cell is subjected to vibration, impact, or other environments, and the electrode assembly moves inside the casing, the interaction force between the lower plastic of the cover plate and the electrode assembly will also increase. Under these circumstances, the edges and corners of the electrode assembly are often damaged by the lower plastic, which in turn affects the process yield and safety performance of the battery cell.

[0034] Therefore, this embodiment provides a cover plate structure 100 to solve the above problems. The cover plate structure 100 can prevent the edges and corners of the electrode group 200 from being damaged by the lower plastic 1, thereby improving the process yield and safety performance of the battery cell.

[0035] like Figures 1-5 As shown, the cover plate structure 100 of this embodiment includes a lower plastic 1. Both ends of the lower plastic 1 along its own length direction are provided with protrusions 11. Both protrusions 11 are used to abut against the end face of the electrode group 200. The top corners of the two protrusions 11 are provided with notched corner structures 111, which correspond to the corners of the electrode group 200. The edges of the two protrusions 11 facing the end face of the electrode group 200 are provided with chamfered structures 112, which correspond to the edges of the electrode group 200 facing the end face of the lower plastic 1.

[0036] The cover structure 100 avoids damage to the edges and corners of the electrode group 200 by setting chamfered structures 112 and notched corner structures 111 at the edges and corners of the end face of the lower plastic 1 corresponding to the electrode group 200. This ensures the structural integrity of the electrode group 200 after it is installed in the casing, improves the process yield of the battery cell, and helps to ensure that the edges and corners of the electrode group 200 are not damaged by the lower plastic 1 during the use of the battery cell, thereby improving the safety performance of the battery cell.

[0037] Optionally, the space between the two protrusions 11 of the lower plastic 1 is used to accommodate the tabs 201 of the electrode assembly 200. A through hole is provided here so that the tabs 201 can pass through the through hole and connect to the output terminal on the top cover 2.

[0038] Optionally, the lower plastic 1 has corner-cut structures 111 at each of the four corners corresponding to the electrode group 200. In this embodiment, the lower plastic 1 is generally rectangular, and the width of the two protrusions 11 is the same as the width of the lower plastic 1, and the two protrusions 11 are located at both ends of the lower plastic 1 along its own length direction. One protrusion 11 has corner-cut structures 111 at its two apex corners, and these two apex corners are located at one end of the length direction of the lower plastic 1 and at both ends of the width direction of the lower plastic 1. The other protrusion 11 also has corner-cut structures 111 at its two apex corners, and these two apex corners are located at the other end of the length direction of the lower plastic 1 and at both ends of the width direction of the lower plastic 1. This allows the four notched corner structures 111 of the lower plastic 1 to correspond to the four corners of the end face of the electrode group 200 facing the lower plastic 1, thus allowing the lower plastic 1 to avoid the four corners of the end face of the electrode group 200 facing the lower plastic 1 and preventing the lower plastic 1 from damaging the four corners of the electrode group 200.

[0039] Optionally, the protrusion direction of the protrusion 11 is consistent with the thickness direction of the lower plastic 1, and the end face of the protrusion 11 that abuts against the electrode assembly 200 is flat to ensure that the abutment force is relatively balanced.

[0040] Optionally, the notched structure 111 is triangular prism-shaped, that is, the notched structure 111 can be conceived as being formed by cutting off part of the material along the protruding direction of the protrusion 11, and the notched structure 111 does not extend to the position of the lower plastic 1 near the top cover 2.

[0041] like Figure 4As shown, optionally, the maximum dimension 'a' of the notched structure 111 along the length of the lower plastic 1 ranges from 3mm to 6mm. The maximum dimension 'a' of the notched structure 111 along the length of the lower plastic 1 is the dimension of the right-angled side of the notched structure 111 along the length of the lower plastic 1. When this dimension 'a' is less than 3mm, due to processing and assembly errors, the protrusion 11 may still press against the corner of the electrode assembly 200, meaning the notched structure 111 may fail. When this dimension 'a' is greater than 6mm, the size of the protrusion 11 is limited along the length of the lower plastic 1. The protrusion 11 cannot be too long; otherwise, the accommodating space of the electrode tabs 201 of the electrode assembly 200 will be too narrow, easily causing quality problems such as tearing of the electrode tabs 201 under pressure. Therefore, the size of the protrusion 11 is limited. If the dimension 'a' is too large, the two oppositely arranged sides of the protrusion 11 along the width of the lower plastic 1 will have too small an area, affecting the structural strength of the protrusion 11 and making it prone to deformation under stress. Therefore, when the maximum dimension a of the missing corner structure 111 along the length direction of the lower plastic 1 is in the range of 3mm-6mm, the avoidance effectiveness of the missing corner structure 111 and the structural strength of the protrusion 11 can be balanced.

[0042] like Figure 5 As shown, optionally, the maximum dimension b of the notched structure 111 along the width direction of the lower plastic 1 ranges from 3mm to 6mm. The maximum dimension b of the notched structure 111 along the width direction of the lower plastic 1 is the dimension of the right-angle side of the notched structure 111 along the width direction of the lower plastic 1. When this dimension b is less than 3mm, due to processing errors and assembly errors, the protrusion 11 may still press against the corner of the electrode assembly 200, that is, the notched structure 111 may fail. When this dimension b is greater than 6mm, because the thickness of the blade battery is small, that is, the dimension of the protrusion 11 along the width direction of the lower plastic 1 is small. If the dimension b is too large, the two sides of the protrusion 11 that are opposite each other along the length direction of the lower plastic 1 will have too small an area, which will affect the structural strength of the protrusion 11. The protrusion 11 is easy to deform under force, which will cause the end of the electrode assembly 200 near the length direction of the lower plastic 1 to receive too little resistance from the protrusion 11, resulting in more concentrated force on the electrode assembly 200 and easy deformation. Therefore, when the maximum dimension b of the missing corner structure 111 along the width direction of the lower plastic 1 is in the range of 3mm-6mm, the avoidance effectiveness of the missing corner structure 111 and the structural strength of the protrusion 11 can be balanced.

[0043] Optionally, in this embodiment, the notched structure 111 is a right-angled prism, that is, the maximum dimension a of the notched structure 111 along the length direction of the lower plastic 1 is equal to the maximum dimension b of the notched structure 111 along the width direction of the lower plastic 1.

[0044] Optionally, the ratio of the dimension of the notched structure 111 along the thickness direction of the lower plastic 1 to the maximum thickness of the lower plastic 1 ranges from 30% to 60%. When the ratio of the dimension of the notched structure 111 along the thickness direction of the lower plastic 1 to the maximum thickness of the lower plastic 1 is less than 30%, due to processing errors and assembly errors, the protrusion 11 may still press against the corner of the electrode assembly 200, meaning the notched structure 111 may fail. When the ratio of the dimension of the notched structure 111 along the thickness direction of the lower plastic 1 to the maximum thickness of the lower plastic 1 is greater than 60%, the notched structure 111 is too deep, which can easily lead to weak end structure strength of the protrusion 11 along the length direction of the lower plastic 1, causing problems such as easy deformation under stress.

[0045] Optionally, the two protrusions 11 have two bevels on their end faces facing the pole group 200. That is, the protrusions 11 have bevels at the positions where the notched corner structure 111 is opened. The bevels are located on the end faces of the protrusions 11 facing the pole group 200. The two bevels correspond to the two corners of the pole group 200 respectively. The bevels have chamfered structures 112 to prevent the relatively sharp bevels from damaging the corners of the pole group 200, which can further protect the corners of the pole group 200.

[0046] like Figure 2 As shown, optionally, chamfered structures 112 are provided at all four edges of the lower plastic 1 corresponding to one end of the electrode assembly 200, so as to ensure that the edges of the electrode assembly 200 are not damaged by the protrusions 11, where the two protrusions 11 may come into contact with the edges of the electrode assembly 200. In addition, as mentioned above, chamfered structures 112 are also provided at the notched corner structure 111.

[0047] like Figure 4 As shown, optionally, the maximum dimension c of the chamfer structure 112 along the protrusion direction of the protrusion 11 can range from 0.5mm to 1.5mm. If the maximum dimension c of the chamfer structure 112 along the protrusion direction of the protrusion 11 is less than 0.5mm, due to processing and assembly errors, the protrusion 11 may still press against the edge of the electrode assembly 200, meaning the chamfer structure 112 may fail. If the maximum dimension c of the chamfer structure 112 along the protrusion direction of the protrusion 11 is greater than 1.5mm, it will affect the various sides of the protrusion 11 that adhere to the shell body, reducing the area of ​​these sides too much, which will also affect the structural strength of the protrusion 11. In addition, if the maximum dimension c of the chamfer structure 112 along the protrusion direction of the protrusion 11 is greater than 1.5mm, the area of ​​the protrusion 11 that adheres to the end face of the electrode assembly 200 will also be reduced too much, resulting in excessive pressure from the protrusion 11 against the electrode assembly 200, which may easily damage the end face of the electrode assembly 200.

[0048] Optionally, the sides of the four corners of the protrusion 11 corresponding to the pole group 200 are all set as curved transitions 113. That is, the two sides of the side of the protrusion 11 that is attached to the shell body among the two sides that are arranged opposite to each other along the length direction of the lower plastic 1 are set as curved transitions 113, and the two sides of the side of the protrusion 11 that is attached to the shell body among the two sides that are arranged opposite to each other along the length direction of the lower plastic 1 are also set as curved transitions 113, so as to prevent sharp sides from scratching other components.

[0049] like Figure 1 As shown, this embodiment also provides a battery cell, including an electrode assembly 200, a housing body (not shown in the figure) and the aforementioned cover plate structure 100. The cover plate structure 100 is sealed at the opening at one end of the housing body along its own length direction, and the electrode assembly 200 is located inside the housing body.

[0050] Optionally, in this embodiment, the positive and negative outputs are respectively located at both ends along the length of the shell body. Optionally, the cover plate structure 100 is located at the negative terminal, and a second cover plate 300 and an end plate 400 are located at the positive terminal. The end plate 400 is used to contact the end face of the electrode assembly 200 and to provide bending space for the positive electrode tab. That is, the negative output end 500 is located on the cover plate structure 100, and the positive output end 600 is located on the second cover plate 300. Of course, in other embodiments, both ends of the cover plate can be set to the cover plate structure 100 described above, without the end plate 400, or the cover plate structure 100 can be set at the positive terminal, and the end plate 400 can be set at the negative terminal. Adjustments can be made according to actual needs.

[0051] Optionally, the compression of the electrode assembly 200 along the length of the casing body is in the range of 3mm-5mm to prevent the electrode assembly 200 from shaking within the casing body of the battery cell.

[0052] The assembly process of this battery cell includes: first, welding the negative electrode tab to the negative output terminal 500 of the cover plate structure 100; then, wrapping the electrode assembly 200 with an insulating film, heat-sealing one end of the insulating film to the lower plastic 1 of the cover plate structure 100 at the negative end, and heat-sealing the other end of the insulating film to the end plate 400 at the positive end. Next, pushing the electrode assembly 200 into the casing body completes the casing installation; then, welding the cover plate structure 100 to the casing body; welding the positive electrode tab to the positive output terminal 600 on the second cover plate 300; and finally, welding the second cover plate 300 to the casing body.

[0053] By incorporating a notched corner structure 111 and a chamfered corner structure 112, this battery cell can prevent the edges and corners of the electrode assembly 200 from being damaged by the lower plastic 1, resulting in higher process yield and safety performance.

[0054] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A cover plate structure, characterized in that, The device includes a lower plastic (1), which has protrusions (11) at both ends along its length. Both protrusions (11) are used to abut against the end face of the electrode assembly (200). The top corners of the two protrusions (11) are provided with a notched corner structure (111), which corresponds to the corner of the electrode assembly (200). The edges of the two protrusions (11) facing the end face of the electrode assembly (200) are provided with a chamfered structure (112), which corresponds to the edge of the end face of the electrode assembly (200) facing the lower plastic (1).

2. The cover plate structure according to claim 1, characterized in that, The maximum dimension a of the notched structure (111) along the length direction of the lower plastic (1) ranges from 3mm to 6mm. And / or, the maximum dimension b of the notched structure (111) along the width direction of the lower plastic (1) ranges from 3mm to 6mm.

3. The cover plate structure according to claim 1, characterized in that, The ratio of the dimension of the notched structure (111) along the thickness direction of the lower plastic (1) to the maximum thickness of the lower plastic (1) ranges from 30% to 60%.

4. The cover plate structure according to claim 1, characterized in that, The missing corner structure (111) is triangular prism.

5. The cover plate structure according to claim 1, characterized in that, The two protrusions (11) have two bevels on their end faces facing the pole group (200), and the two bevels correspond to the two corners of the pole group (200), and the bevels have the chamfer structure (112).

6. The cover plate structure according to any one of claims 1-5, characterized in that, The maximum dimension c of the chamfered structure (112) along the protrusion direction of the protrusion (11) ranges from 0.5mm to 1.5mm.

7. The cover plate structure according to any one of claims 1-5, characterized in that, The lower plastic (1) is provided with the corner-cut structure (111) at each of the four corners corresponding to the pole group (200); And / or, the lower plastic (1) is provided with the chamfered structure (112) at each of the four edges corresponding to one end of the electrode group (200).

8. The cover plate structure according to any one of claims 1-5, characterized in that, The sides of the protrusion (11) corresponding to the four corners of the pole group (200) are all provided with curved transitions (113).

9. A battery cell, characterized in that, It includes an electrode assembly (200), a shell body, and a cover plate structure as described in any one of claims 1-8, wherein the cover plate structure (100) is sealed to an opening at one end of the shell body along its own length direction, and the electrode assembly (200) is located within the shell body.

10. The battery cell according to claim 9, characterized in that, The compression of the pole group (200) along the length of the shell body ranges from 3mm to 5mm.

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