Pole group protection structure, battery cell and battery pack

Abstract

The utility model relates to battery technical field discloses a kind of pole group protection structure, battery cell and battery pack, the pole group protection structure includes protection film main body and bottom support plate.Protection film main body is used to be cladded on the lateral wall of battery cell, protection film main body is in box body structure, both ends of box body structure are with opening;Bottom support plate is oppositely arranged with the bottom wall of battery cell, and bottom support plate is set in the position of opening, and cover and seal opening.The pole group protection structure of the utility model can directly surround protection film main body on pole group lateral wall, realize the one-step forming of cladding operation, then bottom support plate and the pole group after winding film are sequentially placed into shell, so that bottom support plate cooperates with protection film main body, the cladding of pole group is completed, to greatly reduce operation step, simplify assembly processing technology, avoid the quality defects of not cladded in place caused by multiple folding procedures and the problems such as scratch damage caused when pole group enters shell, improve product yield, improve processing efficiency, help to enhance product competitiveness.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to an electrode group protection structure, a battery cell, and a battery pack. Background Technology

[0002] During battery manufacturing, a film is typically wrapped around the electrode assembly to provide physical protection and prevent damage during subsequent transportation and use, thus affecting the battery's lifespan.

[0003] Currently, the membrane body includes a bottom wall covering membrane and a pair of side wall covering membranes disposed on both sides of the bottom wall covering membrane. Specifically, the operation steps for wrapping the electrode assembly membrane body are as follows: First, the bottom support sheet is fixedly connected to the bottom wall covering membrane; then, one of the side wall covering membranes covers the large surface A of the electrode assembly and is fixedly connected to the large surface A of the electrode assembly; next, the membrane body is folded over until the other side wall covering membrane covers the large surface B of the electrode assembly and is fixedly connected to the large surface B of the electrode assembly; then, the side wall covering membranes on both sides of the narrow side of the electrode assembly are folded inward and fixedly connected to the narrow side of the electrode assembly; finally, the bottom wall covering membrane at the bottom of the narrow side of the electrode assembly is folded upward and fixedly connected to the narrow side of the electrode assembly.

[0004] However, this method involves complex operating steps and cumbersome processing techniques. The multiple folding processes can lead to quality defects such as incomplete folding of the membrane, causing the electrode assembly to be scratched and damaged during the shell insertion process, or even failing to be inserted into the shell properly, thus affecting production efficiency and product yield. Utility Model Content

[0005] In view of this, the present invention provides an electrode protection structure, a battery cell, and a battery pack to solve the problems in the related technologies where the operation steps for wrapping the electrode assembly are complicated, the processing technology is cumbersome, and there are quality defects such as incomplete folding, which lead to the electrode assembly being scratched and damaged when it is inserted into the casing, or even unable to be inserted into the casing normally, thus affecting production efficiency and product yield.

[0006] Firstly, this utility model provides an electrode group protection structure, including a protective film body and a base plate.

[0007] The protective film body is used to cover the side wall of the electrode assembly. The protective film body has a box structure with openings at both ends.

[0008] The bottom support plate is positioned opposite the bottom wall of the electrode assembly, and the bottom support plate is located at the opening and covers the opening.

[0009] Beneficial Effects: The electrode assembly protection structure provided by this utility model allows the protective film to be directly wrapped around the sidewall of the electrode assembly, achieving a one-step coating process. Then, the base plate and the wrapped electrode assembly are sequentially placed into the housing. In this way, the base plate and the protective film work together to construct a complete electrode assembly protection system. Compared to traditional processes, this method effectively reduces operational steps, significantly simplifies the assembly process, and effectively avoids quality problems such as incomplete coating caused by repeated folding of the protective film. It also eliminates the risk of damage or even failure to properly insert the electrode assembly into the housing due to scratches. This not only significantly improves the product yield and accelerates the production pace, but also enhances the product's competitive advantage in the market while increasing production efficiency.

[0010] In one alternative implementation, the protective film body is a Mylar film.

[0011] In one alternative implementation, at least a portion of the base plate is disposed within the opening.

[0012] In one alternative embodiment, the base plate is provided with a plurality of through holes for the electrolyte to pass through, the plurality of through holes being spaced apart along the length of the base plate.

[0013] In one alternative embodiment, a plurality of protrusions are provided on one side surface of the bottom wall of the base plate away from the electrode assembly, and the plurality of protrusions are spaced apart along the length direction of the base plate.

[0014] In one alternative implementation, the sidewalls of the pole group include a pair of opposing first sidewalls and a pair of opposing second sidewalls;

[0015] The protective film body includes:

[0016] A pair of spaced-apart first diaphragms are respectively attached to a pair of first sidewalls of the electrode assembly;

[0017] The second diaphragm is disposed between a pair of first diaphragms and is attached to one of the second sidewalls of the electrode assembly;

[0018] A pair of third membranes are respectively disposed at one end of a pair of first membranes away from the second membranes, and both of the pair of third membranes are attached to the other second sidewall of the electrode assembly.

[0019] In one optional embodiment, the protective film body is a one-piece molded structure, with a first fold line at the connection between the first film and the second film, and a second fold line at the connection between the first film and the third film.

[0020] In one alternative implementation, it further includes:

[0021] The first adhesive element is used to fix the third diaphragm to the second sidewall of the electrode assembly;

[0022] The second adhesive element is used to securely connect the pair of the third diaphragms.

[0023] Secondly, this utility model also provides a battery, including a casing, an electrode assembly, and an electrode assembly protection structure as described in any of the above technical solutions.

[0024] The pole group is housed within the pole group protection structure;

[0025] The housing is located outside the electrode group protection structure, with the bottom support plate placed on the inner bottom surface of the housing.

[0026] Beneficial effects: The battery cell provided by this utility model includes the above-mentioned electrode group protection structure and has all the beneficial effects of the electrode group protection structure, which will not be repeated here.

[0027] Thirdly, this utility model also provides a battery pack, including the battery cells described in the above technical solutions.

[0028] Beneficial effects: The battery pack provided by this utility model includes the above-mentioned battery cells and has all the beneficial effects of battery cells, which will not be repeated here. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is an exploded view of the electrode group protection structure according to an embodiment of the present utility model;

[0031] Figure 2 This is a schematic diagram of the structure of the base plate in an embodiment of the present utility model;

[0032] Figure 3 This is a schematic diagram of the unfolded structure of the protective film body according to an embodiment of the present utility model;

[0033] Figure 4 This is a schematic diagram of the pole assembly according to an embodiment of the present invention;

[0034] Figure 5 This is one of the schematic diagrams illustrating the operation steps of the electrode group protection structure according to an embodiment of this utility model;

[0035] Figure 6 This is the second schematic diagram of the operation steps of the electrode group protection structure according to an embodiment of this utility model.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Protective film body; 101. Opening; 102. First diaphragm; 103. Second diaphragm; 104. Third diaphragm; 105. First fold line; 106. Second fold line; 2. Base plate; 201. Through hole; 202. Protrusion; 3. Electrode assembly; 301. First sidewall; 302. Second sidewall; 303. Bottom wall; 4. First adhesive component; 5. Second adhesive component. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0039] In the field of battery manufacturing, to ensure that the electrode assembly is not physically damaged during transportation and use and to extend the battery's lifespan, a protective film is usually wrapped around the outside of the electrode assembly. In related technical solutions, the film structure consists of a bottom wall coating film and side wall coating films symmetrically arranged on both sides.

[0040] The specific coating process is as follows: First, the bottom support piece is fixedly connected to the bottom wall coating film; then, the side wall coating film is covered and fixed to the large surface A of the electrode assembly; next, the other side wall coating film is attached and fixed to the large surface B of the electrode assembly by folding; then, the side wall coating films on both sides of the narrow side of the electrode assembly are folded inward and fixed in sequence; finally, the bottom wall coating film is folded upward from the bottom of the narrow side of the electrode assembly and fixed.

[0041] However, this traditional process has significant drawbacks. The complex, multi-step folding operation not only results in a lengthy processing flow but also makes it prone to incomplete folding of the membrane during actual production. Such quality issues can cause the electrode assembly to be scratched and damaged during the casing process, and in severe cases, it may even be impossible to install it properly, thus negatively impacting production efficiency and product yield.

[0042] Therefore, this utility model embodiment provides a pole group protection structure to solve or improve the problems existing in related technologies.

[0043] The following is combined Figures 1 to 6 This describes the electrode protection structure, battery cell, and battery pack of embodiments of the present invention.

[0044] According to an embodiment of the present invention, in a first aspect, a pole group protection structure is provided, such as... Figure 1As shown, the electrode assembly protection structure includes a protective film body 1 and a bottom support plate 2. Specifically, the protective film body 1 is used to cover the side wall of the electrode assembly 3. The protective film body 1 has a box structure, and both ends of the box structure have openings 101. The bottom support plate 2 is disposed opposite to the bottom wall 303 of the electrode assembly 3. The bottom support plate 2 is positioned at the opening 101 and covers the opening 101.

[0045] Specifically, in practical applications, a winding wrapping method can be adopted. First, one end of the protective film body 1 is fixed to one side of the electrode assembly 3. Then, it is wound around the side of the electrode assembly 3. Finally, the other end of the protective film body 1 is fixed to the same side, completing the complete wrapping of the side wall of the electrode assembly 3. Then, the bottom support plate 2 can be placed directly on the inner bottom surface of the shell, and the wound and wrapped electrode assembly 3 is then inserted into the shell. Thus, the bottom support plate 2 can isolate the electrode assembly 3 from the shell, preventing damage to the electrode assembly 3 from the bottom of the shell. Moreover, the protective film body 1 eliminates the bottom film, simplifying the overall structure, simplifying the cutting and processing process, saving protective film material, reducing costs, and allowing for direct winding when wrapping the electrode assembly 3. The operation is simple, and different tension effects can be achieved by adjusting the winding tension, making it more flexible and convenient to use.

[0046] This configuration allows the protective film body 1 to be directly wrapped around the side wall of the electrode assembly 3, achieving a one-step coating process. Then, the base plate 2 and the wrapped electrode assembly 3 are sequentially placed into the housing. The base plate 2 and the protective film body 1 work together to form a complete protective system for the electrode assembly 3. Compared to traditional processes, this method effectively reduces operational steps, significantly simplifies the assembly process, and effectively avoids quality problems such as incomplete coating caused by repeated folding of the protective film. It also eliminates the risk of damage or even failure to properly insert the electrode assembly 3 into the housing due to scratches. This not only significantly improves product yield and accelerates production, but also enhances the product's competitive advantage in the market while increasing production efficiency.

[0047] In some embodiments, the protective film body 1 is a Mylar film (polyethylene terephthalate film). As a high-performance insulating material, the Mylar film effectively prevents short circuits between the positive and negative electrodes, especially at the electrode edges and tab areas, resisting the risk of short circuits caused by metal burrs or external pressure, ensuring the safety of the internal circuitry of the battery cell. Secondly, the Mylar film, with its excellent mechanical strength and toughness, provides reliable protection during electrode assembly, preventing diaphragm damage and electrode coating peeling, ensuring the integrity of the electrode structure. Furthermore, the Mylar film has good heat resistance, maintaining a stable physical structure when exposed to the heat generated during battery cell charging and discharging or high-temperature environments, avoiding impact on battery cell performance due to thermal shrinkage or melting. Simultaneously, the Mylar film exhibits excellent chemical inertness to the electrolyte, effectively resisting corrosion, significantly extending the service life of the electrode group 3, and improving the long-term reliability of the battery cell. Finally, by wrapping with the Mylar film, the electrode group shape can be stabilized, preventing displacement or deformation of the electrode sheets and diaphragm during subsequent processing, ensuring the precision of the battery cell manufacturing process. Furthermore, in response to the problem that sharp metal burrs are easily generated on the edges of the electrode sheets after the electrode assembly is cut and processed, the Mylar film can form a physical barrier to tightly isolate the burrs, effectively avoiding the risk of short circuit caused by burrs piercing the separator, and building a solid defense for the safety performance of the battery cell.

[0048] In some embodiments, at least a portion of the base plate 2 is disposed within the opening 101. That is, the side of the protective film body 1 facing the base plate 2 wraps around the outside of the base plate 2, achieving a tight fit between the two. Thus, the base plate 2 is at least partially embedded within the opening 101 of the protective film body 1, forming an embedded connection structure. This construction effectively conceals the connection gap between the base plate 2 and the protective film body 1, preventing it from being exposed to the inner wall of the bottom of the housing. Consequently, even if there are metal burrs on the bottom of the housing, they cannot pierce the electrode assembly 3 through this connection gap, constructing a reliable physical protective barrier and significantly improving the safety and stability of the electrode assembly 3 during assembly.

[0049] In some embodiments, such as Figure 1 As shown, the base plate 2 is provided with multiple through holes 201 for the electrolyte to pass through, and the multiple through holes 201 are spaced apart along the length direction of the base plate 2. Specifically, as shown... Figure 2 As shown, multiple through holes 201 can be arranged in groups, with each group including at least two through holes 201. The through holes 201 are spaced apart along the width direction of the base plate 2. Furthermore, multiple groups of through holes 201 are spaced apart along the length direction of the base plate 2. It should be noted that the aperture size, spacing, and other parameters of the multiple through holes 201 can be precisely adjusted and controlled according to the actual design requirements such as the capacity of the electrode group 3, electrolyte characteristics, and the application scenario of the battery cell, ensuring optimal ion transport efficiency and battery cell performance under different operating conditions.

[0050] With this configuration, the electrolyte can penetrate into the electrode assembly 3 through the through holes 201, and the spaced through holes 201 form an array layout, which not only ensures the uniform penetration of the electrolyte at the bottom of the electrode assembly 3, but also provides an efficient channel for ion transport during the charging and discharging process of the battery cell, effectively improving the electrochemical performance and cycle stability of the battery cell.

[0051] In some embodiments, such as Figure 2 As shown, the bottom support plate 2 has multiple protrusions 202 on one side surface away from the bottom wall 303 of the electrode assembly 3. These protrusions 202 are spaced apart along the length of the bottom support plate 2. Specifically, the protrusions 202 can be dots or ridges, etc. For example, such as... Figure 2 As shown, the protrusion 202 is a ridge, which extends along the length of the base plate 2, and multiple ridges are spaced apart along the length of the base plate 2. Optionally, the multiple ridges are arranged in an array and are evenly distributed on the surface of the base plate 2.

[0052] With this design, when the base plate 2 is placed inside the housing, the multiple protrusions 202 on the surface of the base plate 2 facing the housing increase the roughness of the contact surface between the base plate 2 and the housing, significantly improving the coefficient of friction between them and effectively suppressing relative displacement. This structural design fundamentally avoids the risk of positional displacement of the electrode group 3 caused by the sliding of the base plate 2, eliminating potential safety hazards and providing reliable assurance for the stability and safety of the overall cell structure.

[0053] In some embodiments, such as Figure 4 As shown, the sidewalls of pole group 3 include a pair of opposing first sidewalls 301 and a pair of opposing second sidewalls 302. Specifically, taking a square pole group as an example, the pair of first sidewalls 301 represent two large faces of the pole group, and the pair of second sidewalls 302 represent two narrow faces of the pole group.

[0054] like Figure 3 As shown, the protective film body 1 includes a pair of first diaphragms 102, a second diaphragm 103, and a pair of third diaphragms 104. Specifically, the pair of first diaphragms 102 are spaced apart, and each pair of first diaphragms 102 is respectively attached to a pair of first sidewalls 301 of the electrode group 3. That is, the two first diaphragms 102 are used to cover the large surfaces of the two electrode groups. The second diaphragm 103 is disposed between the pair of first diaphragms 102, and the second diaphragm 103 is attached to one of the second sidewalls 302 of the electrode group 3. That is, the second diaphragm 103 covers one of the narrow sidewalls of the electrode group. The pair of third diaphragms 104 are respectively disposed at the ends of the pair of first diaphragms 102 away from the second diaphragms 103, and each pair of third diaphragms 104 is attached to the other second sidewall 302 of the electrode group 3. That is, the two third diaphragms 104 cooperate to cover the other narrow sidewall of the electrode group.

[0055] Specifically, in practical applications, such as Figure 5 As shown, firstly, the third diaphragm 104 at one end of the protective film body 1 is precisely attached and fixed to the second sidewall 302. Then, each diaphragm is sequentially wrapped around the sidewall of the electrode assembly 3, as follows. Figure 6 As shown, the third membrane 104 at the other end of the protective film body 1 is also fixed on the second side wall 302 on the same side, thereby forming a closed-loop covering structure for the side of the electrode group 3, realizing the precise matching of the protective film body 1 and the electrode group 3, ensuring the coverage fit, and providing all-round protection for the electrode group 3.

[0056] In some embodiments, such as Figure 3 As shown, the protective film body 1 is a one-piece molded structure. A first fold line 105 is provided at the connection between the first diaphragm 102 and the second diaphragm 103, and a second fold line 106 is provided at the connection between the first diaphragm 102 and the third diaphragm 104. That is to say, the first diaphragm 102, the second diaphragm 103, and the third diaphragm 104 are designed as a single piece, and the protective film body 1 has a long strip structure. Furthermore, fold lines are provided at the junctions of the first diaphragm 102 and the second diaphragm 103, as well as at the junctions of the first diaphragm 102 and the third diaphragm 104, to ensure accurate fit with the sidewalls of the electrode assembly 3.

[0057] This integrated molding design, by constructing a continuous and uninterrupted protective structure, significantly enhances the overall protective capability of electrode assembly 3. Furthermore, this design greatly simplifies the cutting process of the protective film body 1, effectively shortening the production cycle and significantly improving production efficiency. In addition, the folded design allows for flexible folding and wrapping of the protective film body 1, greatly reducing the difficulty of operation for workers and significantly enhancing the operability and adaptability of the process, providing strong support for an efficient and convenient production process.

[0058] In some embodiments, such as Figure 5 As shown, the electrode assembly protection structure also includes a first adhesive member 4 and a second adhesive member 5. The first adhesive member 4 is used to fix the third diaphragm 104 to the second sidewall 302 of the electrode assembly 3, and the second adhesive member 5 is used to fix a pair of third diaphragms 104 together. Specifically, the first adhesive member 4 and the second adhesive member 5 can be tape or glue, etc. For example, taking tape as an example, the specific wrapping process is as follows: Figure 5 As shown, the third diaphragm 104 at one end of the protective film body 1 is bonded and fixed to the second sidewall 302 of the electrode assembly 3 by the first adhesive 4, and then the protective film is wrapped around the sidewall of the electrode assembly 3 in sequence, and finally as shown. Figure 6 As shown, two third diaphragms 104 located on the same side wall 302 are bonded and fixed to each other by the second adhesive 5, thereby realizing the fixed connection between the protective film body 1 and the electrode group 3.

[0059] This design ensures that the protective film body 1 and the sidewall of the electrode assembly 3 are tightly fitted and fixed, preventing the film from shifting or loosening due to vibration, compression, etc. Furthermore, the bonding operation is simple and efficient, requiring no complex equipment for quick fixation, significantly shortening assembly time. It should be noted that the number of the first adhesive component 4 and the second adhesive component 5 can be determined according to actual usage requirements.

[0060] According to an embodiment of the present invention, in a second aspect, a battery cell is also provided, including a housing, an electrode group 3, and an electrode group protection structure. Specifically, the electrode group protection structure is the same as that in the above embodiments, and the electrode group 3 is disposed within the electrode group protection structure. The housing is disposed outside the electrode group protection structure, wherein the bottom support plate 2 is placed on the inner bottom surface of the housing.

[0061] The battery cell provided in this embodiment includes the electrode group protection structure in the above embodiments, and has all the beneficial effects of the electrode group protection structure, which will not be repeated here.

[0062] According to an embodiment of the present invention, in a third aspect, a battery pack is also provided, including the battery cells described in the above embodiments.

[0063] The battery pack provided in this embodiment includes the battery cells in the above embodiments and has all the beneficial effects of the battery cells, which will not be repeated here.

[0064] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A pole group protection structure, characterized in that, include: The protective film body (1) is used to cover the side wall of the electrode group (3). The protective film body (1) has a box structure, and both ends of the box structure have openings (101). The bottom support plate (2) is disposed opposite to the bottom wall (303) of the pole group (3), and the bottom support plate (2) is disposed at the position of the opening (101) and covers the opening (101).

2. The electrode group protection structure according to claim 1, characterized in that, The protective film body (1) is a Mylar film.

3. The electrode group protection structure according to claim 1 or 2, characterized in that, At least a portion of the base plate (2) is disposed within the opening (101).

4. The electrode group protection structure according to claim 1 or 2, characterized in that, The base plate (2) is provided with a plurality of through holes (201) for the electrolyte to pass through, and the plurality of through holes (201) are spaced apart along the length direction of the base plate (2).

5. The electrode group protection structure according to claim 1 or 2, characterized in that, The bottom support plate (2) has a plurality of protrusions (202) on one side surface away from the bottom wall (303) of the pole group (3), and the plurality of protrusions (202) are distributed at intervals along the length direction of the bottom support plate (2).

6. The electrode group protection structure according to claim 1 or 2, characterized in that, The sidewalls of the pole group (3) include a pair of opposing first sidewalls (301) and a pair of opposing second sidewalls (302); The protective film body (1) includes: A pair of spaced-apart first diaphragms (102) are respectively attached to a pair of first sidewalls (301) of the electrode assembly (3); A second diaphragm (103) is disposed between a pair of first diaphragms (102), and the second diaphragm (103) is in contact with one of the second sidewalls (302) of the electrode assembly (3); A pair of third diaphragms (104) are respectively disposed at one end of a pair of first diaphragms (102) away from the second diaphragm (103), and both of the third diaphragms (104) are attached to another second sidewall (302) of the electrode assembly (3).

7. The electrode group protection structure according to claim 6, characterized in that, The protective film body (1) is an integrally molded structure. A first fold line (105) is provided at the connection between the first film (102) and the second film (103), and a second fold line (106) is provided at the connection between the first film (102) and the third film (104).

8. The electrode group protection structure according to claim 6, characterized in that, Also includes: The first adhesive element (4) is used to fix the third diaphragm (104) to the second sidewall (302) of the electrode assembly (3); The second adhesive element (5) is used to fix a pair of the third membranes (104) together.

9. A battery cell, characterized in that, include: The pole group protection structure according to any one of claims 1 to 8; The electrode group (3) is disposed within the electrode group protection structure; The housing is disposed outside the electrode group protection structure, wherein the bottom support plate (2) is placed on the inner bottom surface of the housing.

10. A battery pack, characterized in that, Includes the battery cell described in claim 9.

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