Mylar film and top cover integrated structure and battery cell

Abstract

The utility model relates to the technical field of power battery cells, and provides a mylar film and top cover integrated structure and a battery cell, the mylar film and top cover integrated structure comprises a top cover sheet, a mylar film body, a lower plastic cement and a pole column assembly, the top cover sheet is provided with a pole column hole; the Mylar film body comprises a connecting part, the connecting part is attached to one side of the top cover piece, and a positioning hole is formed in the connecting part; and the lower plastic is arranged on one side, far away from the top cover sheet, of the connecting part, and an insertion hole is formed in the lower plastic. According to the mylar film and top cover integrated structure and the battery cell, the mylar film is integrally arranged on the top cover sheet and the lower plastic, the top cover sheet, the connecting part and the lower plastic are fixed through the pole assembly, and the battery cell top cover and the mylar film are integrally integrated, so that the occupation of the space of the battery cell is further reduced on the basis of the prior art; meanwhile, compared with the mode that a plurality of plastic sheets are arranged on the lower plastic, the production steps are fewer, and the production line cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of power cells, in particular to a structure integrating a mylar film and a top cover and a cell. Background Art

[0002] The mylar film is a polyester film. Coating the cell with the mylar film is a safety process in the battery manufacturing process of the new energy lithium battery industry. The mylar film wrapped on the cell can not only prevent the cell from being scratched when it is installed in the battery case, but also play an insulating role to prevent the cell from directly contacting the metal case of the battery and causing a safety accident. For example, the Mylar film and battery with the publication number CN116247381A set an inner film and an outer film and opened holes in the film to improve the protection of the core package and avoid hindering the flow of liquids such as electrolyte.

[0003] In addition, a top cover assembly and a secondary battery which are convenient for hot melting and adhering to the mylar film with the publication number CN220106700U propose to set a plurality of plastic sheets around the lower plastic, and the plastic sheets can be folded around the connection with the lower plastic, and the plastic sheets are used for hot melting and adhering to the mylar film, which does not occupy the internal space of the cell, and the lower plastic can be made very thin, so as to achieve the effect of weight reduction. However, connecting the lower plastic and the mylar film requires installing and folding the lower plastic first, which increases the production process of the cell, prolongs the production line, and setting plastic sheets on the periphery of the lower plastic also occupies a certain space of the cell, affecting the overall energy density of the cell. Summary of the Utility Model

[0004] In view of this, the utility model provides a structure integrating a mylar film and a top cover and a cell. By integrally arranging the mylar film on the top cover sheet and the lower plastic, and then fixing the top cover sheet, the connecting part and the lower plastic by the pole column assembly, the integral integration of the cell top cover and the mylar film is realized, so as to further reduce the occupation of the cell space on the basis of the existing technology, improve the energy density of the cell, and at the same time, compared with setting a plurality of plastic sheets on the lower plastic, the production steps are less, and the production line cost is reduced.

[0005] The technical solution of the utility model is realized as follows:

[0006] On the one hand, the utility model provides a structure integrating a mylar film and a top cover, including a top cover sheet, a mylar film body, a lower plastic and a pole column assembly. Among them,

[0007] A pole column hole is opened on the top cover sheet;

[0008] The mylar film body includes a connecting part, the connecting part is attached to one side of the top cover sheet, and a positioning hole is opened on the connecting part;

[0009] The lower plastic is disposed on a side of the connecting portion away from the top cover sheet. A jack is defined in the lower plastic. The positioning hole, the pole hole and the jack are located on the same straight line.

[0010] The pole assembly sequentially passes through the positioning hole, the pole hole and the jack, and abuts against opposite sides of the top cover sheet and the lower plastic, so as to relatively fix the top cover sheet, the connecting portion and the lower plastic.

[0011] Based on the above technical solution, preferably, the mylar film body further includes two covering films, which are respectively disposed on two sides in the width direction of the connecting portion, and the covering films are used for fitting the largest surface of the core package.

[0012] Further preferably, the mylar film body further includes a side wing film, which is disposed outside in the length direction of the covering film, so as to be bent and fitted onto the core package through the covering film.

[0013] Further preferably, the mylar film body further includes a bottom film, which is disposed on one of the two covering films and on a side of the covering film away from the connecting portion, and the bottom film is used for fitting to the bottom of the core package.

[0014] Based on the above technical solution, preferably, the pole assembly includes a pole body and a riveting block. Among them,

[0015] The pole body sequentially passes through the positioning hole, the pole hole and the jack, and abuts against a side of the lower plastic away from the top cover sheet. A positioning groove is defined in the pole body.

[0016] The riveting block is disposed on the top cover sheet and is snapped into the positioning groove to fix the pole body and the top cover sheet.

[0017] Further preferably, the pole assembly further includes an upper plastic, which is disposed between the riveting block and the top cover sheet, and the riveting block is inserted into the upper plastic.

[0018] Further preferably, the pole assembly further includes a sealing member, which is sleeved outside the pole body to seal a gap between the pole body and the lower plastic.

[0019] Based on the above technical solution, preferably, an explosion-proof valve is further included. The explosion-proof valve is disposed on the top cover sheet, and a square hole matching the explosion-proof valve is defined in the connecting portion.

[0020] On the other hand, the present utility model provides an electric core, including the above-mentioned mylar film and top cover integrated structure.

[0021] Based on the above technical solutions, preferably, the mylar film body completely wraps around the outside of the core package.

[0022] The mylar film and top cover integrated structure and the battery cell of the present utility model have the following beneficial effects compared with the prior art:

[0023] (1) By integrally arranging the mylar film on the top cover sheet and the lower plastic, and then fixing the top cover sheet, the connecting part and the lower plastic by the pole column assembly, the integrated one-piece of the battery cell top cover and the mylar film is realized, thereby further reducing the occupation of the battery cell space on the basis of the prior art, improving the energy density of the battery cell. At the same time, compared with arranging multiple plastic sheets on the lower plastic, the production steps are fewer, and the production line cost is reduced;

[0024] (2) Two side wing films are arranged in the length direction of the coating film. The side wing films, the coating film and the connecting part are perpendicular to each other pairwise. The side wing films are folded on the outside of the coating film to fit to the winding bending part of the core package to protect this side of the core package. In order to avoid that the side wing films cannot be completely covered, the side wing films on the same side can partially overlap to achieve more effective protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is an exploded view of the mylar film and top cover integrated structure of the present utility model;

[0027] Figure 2 It is an exploded view of the mylar film body of the mylar film and top cover integrated structure of the present utility model;

[0028] Figure 3 It is a connection diagram of the top cover sheet and the pole column assembly of the mylar film and top cover integrated structure of the present utility model;

[0029] Figure 4 It is a partial structure cross-sectional view of the mylar film and top cover integrated structure of the present utility model;

[0030] Figure 5 It is a three-dimensional view of the battery cell of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Next, in combination with the embodiments of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0032] As Figures 1-4 shown, the mylar film and top cover integrated structure of the present utility model includes a top cover sheet 1, a mylar film body 2, a lower plastic 3 and a terminal assembly 4.

[0033] The top cover sheet 1 is provided with terminal holes. The top cover sheet 1 is a square bar-shaped aluminum part, which is the main component of the battery cell top cover, used for sealing the end of the battery cell square shell to achieve the assembly of the whole cell.

[0034] The mylar film body 2 includes a connecting portion 21. The connecting portion 21 is attached to one side of the top cover sheet 1. The connecting portion 21 is provided with positioning holes. The size of the connecting portion 21 is basically the same as that of the connecting portion 21. At the same time, it is closely attached to the bottom of the top cover sheet 1, and the length and width are aligned. When the mylar film body 2 is fully unfolded, the sum of the areas of each surface on one side is greater than the total area outside the core package. Therefore, during the assembly process, the mylar film body 2 can completely cover the outside of the core package to isolate the core package from the square shell.

[0035] The lower plastic 3 is arranged on the side of the connecting portion 21 away from the top cover sheet 1. The lower plastic 3 is provided with insertion holes. The positioning holes, the terminal holes and the insertion holes are all located on the same straight line. The length and width of the lower plastic 3 are basically the same as those of the top cover sheet 1. It cooperates with the connecting portion 21 and the top cover sheet 1 to form a three-layer overlapping structure, pressing the connecting portion 21 tightly between the lower plastic 3 and the top cover sheet 1 to realize the positioning and fixing of the mylar film body 2. On the lower plastic 3, plastic limiting columns are arranged on both sides in the length direction, and the assembly is realized by the plastic limiting columns contacting the inner wall of the square shell.

[0036] The terminal assembly 4 sequentially passes through the positioning holes, the terminal holes and the insertion holes, and abuts against the opposite sides of the top cover sheet 1 and the lower plastic 3 to relatively fix the top cover sheet 1, the connecting portion 21 and the lower plastic 3. The arranged terminal assembly 4 is used to connect the tabs on the core package in addition to that. The number of the terminal assemblies 4 is two, corresponding to the positive and negative terminals respectively. The two terminal assemblies 4 are used to position the top cover sheet 1, the connecting portion 21 and the lower plastic 3 and squeeze from both sides to realize the relative fixation of the three parts. This process does not require gluing and can be realized simultaneously when installing the terminals during the processing, effectively reducing the processing procedures. At the same time, it has good connection stability and avoids the problems existing in gluing.

[0037] As a preferred embodiment, in order to further improve the connection effect, a plurality of hot melt columns distributed in an equidistant array are further provided on the lower plastic 3. At the same time, through holes corresponding to the hot melt columns are provided on the connecting portion 21, and the top cover sheet 1 can be directly connected by ultrasonic hot melting, and the connecting portion 21 can be more effectively fixed during the connection process.

[0038] In this embodiment, the mylar film body 2 further includes two covering films 22, and the two covering films 22 are respectively arranged on both sides in the width direction of the connecting portion 21, and the covering films 22 are used to fit the largest surfaces of the core package.

[0039] When the battery cell core package is put into the shell, the number of the core packages is one or more. However, regardless of the number of the core packages, the largest surfaces are the two side surfaces in the thickness direction when the core package is wound. The two covering films 22 of the mylar film body 2 are bent downward on both sides of the connecting portion 21 and cover the two largest side surfaces of the core package to protect the largest surfaces.

[0040] In addition, the mylar film body 2 further includes side wing films 23, and the side wing films 23 are arranged on the outer sides in the length direction of the covering films 22 so as to be bent and attached to the core package through the covering films 22.

[0041] The number of the side wing films 23 is four, and they are distributed in pairs on both sides of a single covering film 22, that is, two side wing films 23 are arranged on the length direction of a covering film 22. The side wing films 23, the covering films 22 and the connecting portion 21 are perpendicular to each other in pairs. The side wing films 23 are folded on the outer sides of the covering films 22 to be attached to the winding bending portions of the core package to protect this side of the core package. In order to avoid incomplete covering of the side wing films 23, the side wing films 23 on the same side can partially overlap to achieve more effective protection. It should be noted that relief grooves are provided on the side wing films 23, and the positions of the relief grooves correspond to the plastic limit posts to avoid interference between the side wing films 23 and the plastic limit posts after folding.

[0042] Correspondingly, the mylar film body 2 further includes a bottom film 24, and the bottom film 24 is arranged on one of the two covering films 22 and is located on the side of the covering film 22 away from the connecting portion 21, and the bottom film 24 is used to fit to the bottom of the core package.

[0043] During the assembly process, the bottom film 24 is attached to the bottom of the core package. On the bottom film 24, two extended portions are correspondingly provided. The two extended portions are not directly connected to the covering film 22, but are attached to the side wing films 23 during the folding process. Specifically, the bottom film 24 is first folded to the bottom of the core package, and then the extended portions are bent upward, and finally the side wing films 23 are folded to the outside of the core package and the extended portions.

[0044] In this embodiment, the terminal assembly 4 includes a terminal body 41 and a riveting block 42. The terminal body 41 sequentially passes through the positioning hole, the terminal hole, and the jack, and abuts against the side of the lower plastic 3 away from the top cover plate 1. A positioning groove is formed on the terminal body 41. The riveting block 42 is arranged on the top cover plate 1 and is snapped into the positioning groove to fix the terminal body 41 and the top cover plate 1.

[0045] The main body of the terminal body 41 is of a column structure, and its bottom is in a sheet shape. After the sheet-shaped bottom is inserted into the positioning hole, the terminal hole, and the jack, it will be pressed against the lower plastic 3. The provided riveting block 42 is deformed and embedded into the positioning groove of the terminal body 41. The positioning groove is annularly arranged. At the same time, a corresponding installation opening is formed on the riveting block 42, and the inner diameter of the installation opening is smaller than the outer diameter of the positioning groove. When the riveting block 42 is fixed to the terminal body 41, it can cooperate to fix the top cover plate 1, the connecting part 21, and the lower plastic 3.

[0046] In addition, the terminal assembly 4 further includes an upper plastic 43. The upper plastic 43 is arranged between the riveting block 42 and the top cover plate 1, and the riveting block 42 is inserted into the upper plastic 43.

[0047] The upper plastic 43 is used to isolate the top cover plate 1 and the riveting block 42. Through its insulation ability, the upper plastic 43 electrically isolates the top cover plate 1 and the riveting block 42 to prevent a path from being formed between the terminal and the top cover plate 1.

[0048] To prevent the terminal body 41 from contacting the top cover plate 1, the terminal assembly 4 further includes a seal 44. The seal 44 is sleeved on the outside of the terminal body 41 to seal the gap between the terminal body 41 and the lower plastic 3. The seal 44 is similar in structure to the terminal body 41. It is sleeved on the outside of the terminal body 41. By the elastic deformation of the seal 44, the top cover plate 1, the connecting part 21, and the lower plastic 3 are pressed tightly. At the same time, the end of the seal 44 extends into the upper plastic 43 to isolate the terminal body 41 and the top cover plate 1.

[0049] In this embodiment, an explosion-proof valve 5 is further included. The explosion-proof valve 5 is arranged on the top cover plate 1, and a square hole matching the explosion-proof valve 5 is formed on the connecting part 21.

[0050] Corresponding patches are provided on the top cover plate 1 to seal the explosion-proof valve 5. At the same time, on the lower plastic 3, a mesh structure for accommodating the explosion-proof valve 5 and connecting the inside of the battery cell to the explosion-proof valve 5 is also provided.

[0051] Such as Figures 1-5As shown in the figure, the battery cell of the present utility model includes the above-mentioned mylar film and top cover integrated structure, and specifically further includes a square shell, a connecting piece and a battery cell. The connecting piece is arranged between the pole column assembly 4 and the core package, so as to electrically connect the pole column body 41 and the pole ear on the core package in a welding manner. The mylar film body 2 completely wraps the outside of the core package to form an integral body, and is inserted into the square shell, and then the top cover piece 1 is welded to the square shell to seal the edge, forming a complete battery cell.

[0052] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A Mylar film and top cover integrated structure, characterized in that: It comprises a top cover sheet (1), a Mylar membrane body (2), a lower plastic (3) and a pole assembly (4), wherein: The top cover sheet (1) is provided with a pole hole; The Mylar film body (2) comprises a connecting portion (21), the connecting portion (21) is attached to one side of the top cover sheet (1), and a positioning hole is provided on the connecting portion (21); The lower plastic (3) is arranged on a side of the connecting portion (21) away from the top cover sheet (1), and a plug hole is provided on the lower plastic (3), and the positioning hole, the pole hole and the plug hole are all located on the same straight line; The pole assembly (4) passes through the positioning hole, the pole hole and the insertion hole in sequence, and abuts against the opposite sides of the top cover sheet (1) and the lower plastic (3) to relatively fix the top cover sheet (1), the connecting portion (21) and the lower plastic (3).

2. The Mylar film and top cover integrated structure according to claim 1, characterized in that: The Mylar film body (2) further comprises two covering films (22), the two covering films (22) being respectively arranged on both sides of the connecting portion (21) in the width direction, and the covering films (22) being used to fit the largest surface of the core package.

3. The Mylar film and top cover integrated structure as claimed in claim 2, characterized in that: The Mylar film body (2) further comprises a wing film (23), wherein the wing film (23) is arranged on the outside of the covering film (22) in the length direction so as to be bent and adhered to the core package through the covering film (22).

4. The Mylar film and top cover integrated structure as claimed in claim 2, characterized in that: The Mylar film body (2) further comprises a bottom film (24), wherein the bottom film (24) is arranged on one of the two covering films (22) and is located on a side of the covering film (22) away from the connecting portion (21), and the bottom film (24) is used to be attached to the bottom of the core package.

5. The Mylar film and top cover integrated structure according to claim 1, characterized in that: The pole assembly (4) comprises a pole body (41) and a riveting block (42), wherein: The pole body (41) passes through the positioning hole, the pole hole and the insertion hole in sequence, and abuts against the side of the lower plastic (3) away from the top cover sheet (1), and a positioning groove is provided on the pole body (41); The riveting block (42) is arranged on the top cover sheet (1) and is inserted into the positioning groove to fix the pole body (41) and the top cover sheet (1).

6. The Mylar film and top cover integrated structure according to claim 5, characterized in that: The pole assembly (4) further comprises an upper plastic (43), wherein the upper plastic (43) is arranged between the riveting block (42) and the top cover sheet (1), and the riveting block (42) is inserted into the upper plastic (43).

7. The Mylar film and top cover integrated structure according to claim 5, characterized in that: The pole assembly (4) further comprises a sealing member (44), wherein the sealing member (44) is sleeved on the outside of the pole body (41) to seal the gap between the pole body (41) and the lower plastic (3).

8. The Mylar film and top cover integrated structure according to claim 1, characterized in that: It also comprises an explosion-proof valve (5), wherein the explosion-proof valve (5) is arranged on the top cover sheet (1), and the connecting portion (21) is provided with a square hole matching the explosion-proof valve (5).

9. A battery cell, characterized in that: The invention comprises the Mylar film and top cover integrated structure as described in any one of claims 1 to 8.

10. The battery cell according to claim 9, characterized in that: The Mylar membrane body (2) is completely coated on the outside of the core package.

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