Battery cell structure, battery cell module and battery pack

Abstract

The utility model provides a kind of electric core structure, electric core module and battery pack, electric core structure includes at least one electric core monomer and uniform heating plate, electric core monomer includes tab and connecting piece, the connecting piece is electrically connected with the tab;Uniform heating plate is attached to the connecting piece installation.By part for the electric core radiating uniform heating plate extends to the connecting piece position of electric core monomer, and is attached to connecting piece, to be radiated to connecting piece by uniform heating plate, to solve the technical problem of large current connecting piece radiating, improve the service life and reliability of electric core.

Description

Technical Field

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

[0002] When a battery is charging or discharging, if the cell current is too high, the current in the connecting pieces between the positive and negative terminals of the cell will also be too high, generating a lot of heat. If this heat cannot be effectively dissipated, it will affect the lifespan of the cell.

[0003] Therefore, a new technical solution needs to be proposed. Utility Model Content

[0004] The present invention provides a cell structure, a cell module and a battery pack. The cell can effectively dissipate heat from the connecting pieces of the positive and negative electrodes to improve the cell's service life.

[0005] In a first aspect, embodiments of the present invention provide a battery cell structure, comprising:

[0006] At least one battery cell, including a tab and a connecting piece, the connecting piece being electrically connected to the tab; and

[0007] A heat spreader plate is attached to the connecting piece for installation.

[0008] Among these features, by installing a heat spreader on the connecting piece of the battery cell, the heat generated by the connecting piece when the current is too high can be absorbed by the heat spreader, thereby quickly removing the heat emitted by the connecting piece, improving the stability of the battery cell performance, and preventing the connecting piece temperature from being too high and limiting the charging speed, thus improving the user experience.

[0009] In some embodiments, the heat spreader includes a first plate and a second plate that are interconnected. The first plate is mounted to the connecting piece, and the second plate is mounted to the outer wall of the individual battery cell. The first plate is mounted to the connecting piece to absorb heat from it, while the second plate is mounted to the outer wall of the individual battery cell to even out the heat generated locally on the outer wall of the cell, preventing localized overheating and improving temperature uniformity.

[0010] In some embodiments, the heat spreader further includes a third plate, which communicates with the second plate and is disposed on the side opposite to the first plate. The third plate is mounted in contact with the outer wall of the battery cell. The third plate increases the heat dissipation area of ​​the battery cell, further improving its temperature uniformity. The third plate is mounted away from the first plate, which is attached to the connecting piece, and serves as a condensation end, while the first plate can at least be part of the evaporation end.

[0011] In some embodiments, the first plate, the second plate, and the third plate form a C-shaped heat spreader, which surrounds the outer periphery of the battery cell. The C-shape of the heat spreader increases the heat exchange area of ​​the battery cell, allowing for timely removal of heat from excessively hot areas.

[0012] In some embodiments, the battery cell includes a first sidewall and a second sidewall, the area of ​​the first sidewall being smaller than the area of ​​the second sidewall. The second plate is attached to the first sidewall, which has a smaller outer wall area, of the battery cell. Because the relatively larger surface areas on both sides of the battery cell tend to expand after prolonged use, this expansion can cause the heat spreader attached to it to expand as well, leading to deformation and potentially causing thermal management failure of the battery cell, thus affecting the lifespan of the heat spreader. Conversely, the smaller surface areas on both sides of the battery cell expand less, making it less likely for the heat spreader to deform, or ensuring that the deformation is within a controllable range. This improves the lifespan of the heat spreader, enhances battery reliability, and reduces material usage compared to attaching the heat spreader to the second sidewall.

[0013] In some embodiments, the electrode tabs include a positive electrode tab and a negative electrode tab, which are respectively disposed on opposite sides of the same surface of the battery cell. The battery cell is equipped with an explosion-proof valve, which is located between the positive and negative electrode tabs. The positive and negative electrode tabs are provided to accommodate the installation position of the explosion-proof valve.

[0014] In some embodiments, a clearance zone is provided between the heat spreader and the explosion-proof valve to avoid obstructing it. This clearance zone is an area where the heat spreader does not cover the explosion-proof valve; the heat spreader and the explosion-proof valve are at a certain distance. The clearance zone ensures the effective open area of ​​the explosion-proof valve without affecting the original design of the battery cell, allowing the heat spreader to avoid the explosion-proof valve.

[0015] Secondly, a battery module is provided, including the aforementioned cell structure.

[0016] In some embodiments, there are at least two battery cells arranged sequentially, and at least one heat spreader extends along the arrangement direction of the battery cells, covering the outer walls of at least two battery cells and their connecting pieces. By using a heat spreader to attach at least two battery cells together, the gaps between the battery cells can also be utilized as heat transfer directions and heat transfer components, thereby improving heat transfer efficiency, reducing temperature differences between battery cells, and enhancing temperature uniformity among the battery cells.

[0017] In some embodiments, a liquid cooling plate is also included, which is at least partially attached to the outer wall of the heat spreader. The liquid cooling plate is attached to the outer wall of the heat spreader to dissipate heat from the heat spreader, thereby improving the heat dissipation efficiency of the battery module.

[0018] In some embodiments, the liquid cooling plate is mounted against the side of the heat spreader away from the connecting piece. This mounting arrangement facilitates the formation of a condensation end and an evaporation end on the heat spreader, improving heat dissipation efficiency.

[0019] Thirdly, a battery pack is provided, including the aforementioned cell structure or the aforementioned battery module.

[0020] The beneficial effects of the embodiments of the utility model are as follows:

[0021] In an embodiment of this utility model, by extending a portion of the heat dissipation plate used for heat dissipation of the battery cell to the connecting piece position of the battery cell and attaching it to the connecting piece, heat dissipation of the connecting piece is achieved through the heat dissipation plate, thereby solving the technical problem of heat dissipation of the high-current connecting piece and improving the service life and reliability of the battery cell. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments 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.

[0023] Figure 1 This is a three-dimensional structural diagram of the battery module provided in an embodiment of this utility model;

[0024] Figure 2 This is an exploded structural diagram of the battery module provided in an embodiment of this utility model;

[0025] Figure 3 This is a schematic diagram of the heat spreader provided in an embodiment of the present invention;

[0026] Figure 4 This is an exploded structural diagram of another battery module provided in an embodiment of this utility model.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1-Battery cell, 101-Connecting piece, 102-First sidewall, 103-Second sidewall;

[0029] 2-Heat spreader, 201-First plate, 202-Second plate, 203-Third plate;

[0030] 3-Explosion-proof valve;

[0031] 4-Avoidance Zone;

[0032] 5-Liquid cooling plate. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0034] In this application, a battery cell refers to a single battery cell capable of charging and discharging. A battery cell includes a positive electrode, a negative electrode, a separator, an electrolyte, and a casing for encapsulating the positive and negative electrode, separator, and electrolyte. The positive and negative electrode are connected to tabs, and the tabs are connected to conductive connecting pieces 101, which are typically made of aluminum, copper, or a copper-aluminum composite material. The battery cell can be a lithium-ion cell, potassium-ion cell, sodium-ion cell, lithium-sulfur cell, etc., with lithium-ion cells being particularly preferred. During the charging and discharging process of the battery cell, active ions repeatedly insert and extract between the positive and negative electrode. The electrolyte acts as a conductor of ions between the positive and negative electrode.

[0035] Firstly, this utility model provides a battery cell structure, please refer to [link / reference]. Figures 1-2 .in, Figure 1 This is a three-dimensional structural diagram of the battery module provided in an embodiment of this utility model. Figure 2This is an exploded structural diagram of a battery module provided in an embodiment of this utility model. The battery cell includes at least one battery cell 1 and a heat spreader 2. The battery cell 1 includes a tab and a connecting piece 101. The connecting piece 101 is electrically connected to the tab, and the heat spreader 2 is mounted on the connecting piece 101. It can be understood that the connecting piece 101 is connected to the tab, and the battery cell transmits electrical energy to the outside or charges internally through the tab and the connecting piece 101. When the current reaches a certain level, due to the resistance of the connecting piece 101 itself, the current flowing through the connecting piece 101 generates Joule heat due to the resistance. By mounting the heat spreader 2 on the connecting piece 101, the heat spreader 2 can quickly dissipate heat from the connecting piece 101, preventing the temperature of the connecting piece 101 from becoming too high and causing excessively long charging times. In addition, it can improve the temperature uniformity of the battery cell, enhance the high-current performance of the battery cell, reduce the probability of battery cell expansion, and improve the reliability of the battery cell.

[0036] The vapor chamber 2 possesses superior planar heat diffusion capabilities, addressing hotspot heat dissipation issues in individual battery cells 1 or battery modules. The vapor chamber 2 is constructed from two welded metal plates, forming a flat, sealed cavity with an internal vacuum. A small amount of volatile working fluid is injected into the sealed cavity. Capillary structures are located on the inner wall of the sealed cavity, using capillary force to draw the condensed liquid working fluid from the lower-temperature area (condensation end) back to the higher-temperature area (evaporation end). In practice, multiple vapor chambers 2 can be used. One portion of the vapor chamber 2 is attached to the connecting piece 101 to absorb heat from the connecting piece 101 (hot end), while another portion (cold end) extends to other parts of the battery cell.

[0037] In some implementations, please refer to Figures 2-4The heat spreader 2 includes a first plate 201 and a second plate 202 that are interconnected. The first plate 201 is mounted to the connecting piece 101, and the second plate 202 is mounted to the outer wall of the battery cell 1. It can be understood that the first plate 201 and the second plate 202 are connected and form a connected sealed cavity. A working fluid is injected into the sealed cavity, and the inner wall of the sealed cavity has a capillary structure, allowing the working fluid to circulate between the first plate 201 and the second plate 202 to complete heat exchange. Specifically, the first plate 201 is mounted to the connecting piece 101 to absorb heat from the connecting piece 101, and the second plate 202 is mounted to the outer wall of the battery cell 1 to even out the heat generated locally on the outer wall of the battery cell, preventing localized overheating, managing the temperature of the battery cell, and dissipating the generated heat, thereby improving the temperature uniformity of the battery cell. The heat dissipation of the heat dissipation plate 2 can be achieved through its own outer surface, or by attaching a liquid cooling plate 5 to the heat dissipation plate 2. The liquid cooling plate 5 can carry away the heat from the heat dissipation plate 2 to reduce the temperature of the battery cell. The former method, which does not use the liquid cooling plate 5, is suitable for air cooling to remove the heat from the heat dissipation plate 2. The latter method, which uses the liquid cooling plate 5 to remove the heat from the heat dissipation plate 2, is suitable for battery packs with better sealing requirements. In addition, liquid cooling is usually faster than air cooling, and the installation of the liquid cooling plate 5 can more effectively cope with the rapid increase in the temperature of the battery cell.

[0038] In some implementations, please refer to Figure 2 and Figure 4 In a square battery cell 1, the battery cell 1 includes a first sidewall 102 and a second sidewall 103. The area of ​​the first sidewall 102 is smaller than the area of ​​the second sidewall. A second plate 202 is attached to the first sidewall 102 of the battery cell 1. It is understood that after prolonged use, the relatively larger surface areas on both sides of the battery cell are prone to expansion. This expansion causes the heat spreader 2 attached to it to also expand, leading to deformation of the heat spreader 2. This can cause thermal management failure of the battery cell, thus affecting the service life of the heat spreader 2. Conversely, the smaller surface areas on both sides of the battery cell expand less, making it less likely for the heat spreader 2 to deform, or the deformation of the heat spreader 2 is within a controllable range, thereby improving the service life of the heat spreader 2 and increasing battery reliability. Furthermore, compared to attaching the heat spreader 2 to the larger surface area of ​​the battery cell, attaching the heat spreader 2 to the smaller surface areas on both sides of the battery cell reduces material usage. Figure 2 and Figure 4In the middle, the connecting piece 101 is installed on the top of the battery cell 1, and has four sides: two relatively large second sidewalls 103 and two relatively small first sidewalls 102. The first plate 201 and the second plate 202 are two sets. The first plate 201 is mostly or entirely installed on the top surface of the battery cell 1 or its assembly, and the second plate 202 is installed on the smaller first sidewall 102. The first plate 201 and the second plate 202 are connected at a certain angle.

[0039] In some implementations, please refer to Figures 1-3 The heat spreader 2 further includes a third plate 203, which communicates with the second plate 202 and is located on the side opposite to the first plate 201. The third plate 203 is attached to the outer wall of the battery cell 1. It can be understood that the third plate 203 is sequentially connected to the second plate 202 and the first plate 201, wherein the first plate 201 is attached to the connecting piece 101, and the second plate 202 and the third plate 203 are respectively attached to the outer wall of the battery cell. The second plate 202 and the third plate 203 are typically attached to the outer walls of different battery cells. For example, the battery cell has a top surface, on which the connecting piece 101 is provided. The battery cell also has four sides and a bottom surface. A second plate 202 is attached to one side of the battery cell (first sidewall 102), and a third plate 203 is attached to the bottom surface. The second and third plates 202 can completely cover the surfaces they are attached to, or they can cover only a portion of them. The specific size of the covered area and the surfaces to be attached are determined according to design requirements. Specifically, the second plate 202 can be attached to a relatively small area of ​​the battery cell's side surface, or it can be attached to a relatively large area of ​​the battery cell's side surface. When the second plate 202 is attached to a smaller area of ​​the side surface, it can reduce the possibility of deformation of the second plate 202 due to expansion of the larger surface area of ​​the battery cell during long-term use, and it can also reduce the usable area of ​​the heat spreader 2.

[0040] The first plate 201, the second plate 202, and the third plate 203 can be arranged in various shapes, such as a Z-shape or a C-shape. Typically, the first plate 201, the second plate 202, and the third plate 203 form a C-shaped heat exchange plate 2, which surrounds the outer periphery of the battery cell 1. The first plate 201 is located on the top surface of the battery cell, the second plate 202 is located on the side surface, and the third plate 203 is located on the bottom surface. The third plate 203 serves as the condensation end of the heat exchange plate 2, the first plate 201 serves as the evaporation end, and the second plate 202 can serve as either a condensation end or an evaporation end. The C-shaped heat exchange plate 2 increases the heat exchange area of ​​the battery cell 1, effectively removing heat from excessively hot areas.

[0041] In some embodiments, the electrode tabs include a positive electrode tab and a negative electrode tab, which are respectively disposed on opposite sides of the same surface of the battery cell 1. An explosion-proof valve 3 is provided on the battery cell 1, and the explosion-proof valve 3 is disposed between the positive electrode tab and the negative electrode tab. Specifically, the battery cell 1 has a positive electrode tab and a negative electrode tab, located on the same surface of the battery cell 1. Typically, the positive electrode tab and the negative electrode tab are disposed on the top surface of the battery cell 1, and respectively located on opposite sides of the top surface of the battery cell 1. In other words, the positive electrode tab and the negative electrode tab are disposed on the top surface of the battery cell 1 and are spaced a certain distance apart. The explosion-proof valve 3 is disposed between the positive electrode tab and the negative electrode tab of the battery cell 1 to prevent interference between the placement of the positive electrode tab, the negative electrode tab, and the explosion-proof valve 3. It is understandable that the explosion-proof valve 3 is a key safety component of a rechargeable battery. Its core function is to rapidly and directionally release the internal pressure of the battery when a violent chemical reaction occurs due to overcharging, overheating, internal short circuit, external compression, or puncture, resulting in a large amount of gas being generated. This prevents a violent explosion. Therefore, the positive and negative electrodes and the explosion-proof valve 3 should be positioned at a certain distance and should not interfere with each other. Typically, the explosion-proof valve 3 is centrally located between the positive and negative electrodes, each with a connecting piece 101 installed. Therefore, the explosion-proof valve 3 is centrally located between the connecting pieces 101 of the positive and negative electrodes.

[0042] In some embodiments, a clearance area 4 is provided between the heat spreader 2 and the heat spreader 3 to avoid obstructing the explosion-proof valve 3. It is understood that when the explosion-proof valve 3 activates, it needs to quickly release the internal pressure of the battery to prevent battery explosion. The heat spreader 2 on the battery cell needs to be positioned to avoid directly applying the pressure released by the explosion-proof valve 3 to the heat spreader 2, thus preventing a secondary accident. Therefore, the heat spreader 2 needs to provide a clearance area 4 for the explosion-proof valve 3. This clearance area 4 is the area where the heat spreader 2 does not cover the explosion-proof valve 3; the heat spreader 2 and the explosion-proof valve 3 form a certain distance, and the clearance area 4 ensures the effective open area of ​​the explosion-proof valve 3. For example, the positive electrode connecting piece 101 and the negative electrode connecting piece 101 are disposed on the top surface of the battery cell 1, and are respectively located on both sides of the top surface of the battery cell 1. The size of the heat spreader 2 on the top surface of the battery cell matches the size of the connecting piece 101, or the width of the heat spreader 2 on the top surface of the battery cell is approximately the same as the width of the connecting piece 101. This width is the distance from the side of the connecting piece 101 on the top surface of the battery cell away from the explosion-proof valve 3 to the side of the connecting piece 101 close to the explosion-proof valve 3, that is... Figure 2The distance is shown as d in the figure. Therefore, the heat spreader 2 is provided with a connecting piece 101 covering the top surface of the battery cell. This can not only dissipate heat from the connecting piece 101 and prevent the temperature of the connecting piece 101 from becoming too high, thereby quickly adjusting the temperature of the top and side walls of the battery cell and improving the temperature uniformity of the battery cell, but also avoid affecting the original design of the battery cell, so that the heat spreader 2 can avoid the explosion-proof valve 3.

[0043] Secondly, this utility model provides a battery module. The battery module is a key intermediate layer structure in a battery system, integrating basic cell units into a medium-sized unit with stronger functionality, easier management, and basic thermal management and monitoring capabilities. Modular design is crucial for improving the production efficiency, reliability, maintenance convenience, and optimizing thermal management and energy density of the battery system. This battery module includes the aforementioned cell structure, and because it possesses all the technical features of the aforementioned cell structure, it also possesses all its technical effects.

[0044] In some implementations, please refer to Figure 1 , Figure 2 and Figure 4 The battery cell 1 consists of at least two cells arranged sequentially. At least one heat spreader 2 extends along the arrangement direction of the battery cell 1 and covers the outer walls of at least two battery cell 1 cells and their connecting pieces 101. It is understood that at least two battery cell 1 cells are used to form a battery module. Typically, multiple battery cell 1 cells are arranged sequentially. The number of battery cell 1 cells does not limit the scope of protection of this application. For example, 10 battery cell 1 cells are arranged sequentially in one direction to form a battery module. The battery cell 1 cells are flat, square cells. The larger sidewalls of the battery cell 1 cells are installed adjacent to each other, while the two smaller sidewalls of the battery cell 1 cells are located on either side of their arrangement direction and exposed to facilitate installation with the heat spreader 2. The heat spreader 2 is L-shaped and extends along the arrangement direction of the battery cells 1, affixing the connecting pieces 101 on at least two battery cells 1 and the sides of at least two battery cells 1; or the heat spreader 2 is C-shaped and extends along the arrangement direction of the battery cells 1, affixing the connecting pieces 101 on at least two battery cells 1, the sides of at least two battery cells 1, and the bottom surfaces of at least two battery cells 1, so that heat exchange is achieved between at least two battery cells 1 through one heat spreader 2, thereby achieving temperature uniformity among multiple battery cells 1. In a battery module, one heat spreader 2 can be used with all battery cells 1, or multiple heat spreaders 2 can be used with battery cells 1. By affixing at least two battery cells 1 through one heat spreader 2, the gaps between the battery cells 1 can also be utilized as heat transfer directions and heat transfer components, thereby improving heat transfer efficiency, reducing the temperature difference between each battery cell 1, and improving temperature uniformity among the battery cells 1.

[0045] In some implementations, please refer to Figure 1 , Figure 2 and Figure 4 The system also includes a liquid cooling plate 5, which is at least partially attached to the outer wall of the heat spreader 2. It is understood that the heat spreader 2 and the liquid cooling plate 5 are two efficient thermal management technologies that work together to achieve heat dissipation and temperature uniformity control of the battery. The liquid cooling plate 5 utilizes flowing coolant (such as a water-glycol solution) through metal channels to directly absorb heat from the heat spreader 2, forming the cold end of the heat spreader 2. The liquid cooling plate 5 can be attached to the top, side, or bottom surface of the heat spreader 2 to dissipate heat. Typically, the liquid cooling plate 5 is attached to the end away from the heat source. For example, the liquid cooling plate 5 is attached to the side of the heat spreader 2 away from the connecting piece 101, such as attaching the liquid cooling plate 5 to the second plate 202 or the third plate 203 of the heat spreader 2, to improve the heat dissipation efficiency of the battery module.

[0046] Thirdly, this utility model provides a battery pack, including the aforementioned cell structure or the aforementioned battery module. Since the battery pack includes the aforementioned cell structure or battery module, it also possesses all the technical features of the aforementioned cell structure or battery module, and therefore also has all their technical effects.

[0047] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A battery cell structure, characterized in that, include: At least one battery cell (1) includes a tab and a connecting piece (101), wherein the connecting piece (101) is electrically connected to the tab; and The heat spreader (2) is attached to the connecting piece (101) for installation.

2. The cell structure according to claim 1, characterized in that, The heat spreader (2) includes a first plate (201) and a second plate (202) that are connected to each other. The first plate (201) is attached to the connecting piece (101) and the second plate (202) is attached to the outer wall of the battery cell (1).

3. The cell structure according to claim 2, characterized in that, The heat spreader (2) further includes a third plate (203), which is connected to the second plate (202) and is located on the side opposite to the first plate (201). The third plate (203) is attached to the outer wall of the battery cell (1).

4. The cell structure according to claim 3, characterized in that, The first plate (201), the second plate (202) and the third plate (203) are C-shaped and surround the outer periphery of the battery cell (1).

5. The cell structure according to claim 2, characterized in that, The battery cell (1) includes a first sidewall (102) and a second sidewall (103), the area of ​​the first sidewall is smaller than the area of ​​the second sidewall, and the second plate (202) is attached to the first sidewall of the battery cell (1).

6. The cell structure according to claim 1, characterized in that, The electrode tabs include a positive electrode tab and a negative electrode tab. The positive electrode tab and the negative electrode tab are respectively disposed on both sides of the same surface of the battery cell (1). The battery cell (1) is provided with an explosion-proof valve (3), which is disposed between the positive electrode tab and the negative electrode tab.

7. The cell structure according to claim 6, characterized in that, A clearance zone (4) is provided between the heat spreader (2) and the heat spreader (2) to avoid obscuring the explosion-proof valve (3).

8. A battery cell module, characterized in that, Includes the cell structure described in any one of claims 1-7.

9. The cell module according to claim 8, characterized in that, The battery cell (1) consists of at least two cells arranged in sequence, and at least one heat spreader (2) extends along the arrangement direction of the battery cell (1) and covers the outer walls of at least two battery cell (1) and their connecting pieces (101).

10. The cell module according to claim 9, characterized in that, It also includes a liquid cooling plate (5), which is at least partially attached to the outer wall of the heat spreader (2).

11. The cell module according to claim 10, characterized in that, The liquid cooling plate (5) is mounted on the side of the heat spreader (2) away from the connecting piece (101).

12. A battery pack, characterized in that, It includes the cell structure according to any one of claims 1-7 or the cell module according to any one of claims 8-11.

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