Battery cell and battery pack

Abstract

The embodiment of the utility model provides a battery cell and a battery pack, and relates to the technical field of batteries. The battery cell of the battery pack comprises a shell and a cover plate, a cavity is formed in the shell. An opening is formed in one end of the shell. And a naked battery cell is accommodated in the cavity. And a temperature equalizing plate is arranged on the side wall of the shell. And a cavity is formed in the uniform temperature plate. A phase change material is contained in the air. The cover plate is arranged at one end of the opening. The cover plate is connected with the shell so as to seal the cavity. The battery cell of the battery pack can absorb heat generated in the use process of the battery cell, the temperature of the battery cell is reduced, the service life of the battery cell is prolonged, and thermal runaway of the battery is avoided.

Description

Technical Field

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

[0002] To ensure normal operation, lithium-ion cells need to be continuously charged and discharged. However, this charging and discharging process generates heat due to electrochemical reactions and other factors, and the accumulation of heat causes the cell temperature to rise.

[0003] Existing battery cells do not have a cooling structure design. Heat accumulation during operation can shorten the life of the battery cells or even cause thermal runaway, posing a safety hazard. Utility Model Content

[0004] The purpose of this utility model is to provide a battery cell and battery pack that can absorb the heat generated by the battery cell during use, reduce the temperature of the battery cell, improve the service life of the battery cell, and prevent battery thermal runaway.

[0005] The embodiments of this utility model can be implemented as follows:

[0006] In a first aspect, this utility model provides a battery cell, comprising:

[0007] The housing has a cavity inside, an opening at one end, a bare battery cell inside the cavity, a heat spreader on the side wall of the housing, a cavity inside the heat spreader, and a phase change material inside the cavity.

[0008] A cover plate is disposed at one end of the opening and is connected to the housing to close the cavity.

[0009] In an optional embodiment, a groove is provided on the outer side wall of the housing, and the heat spreader is embedded in the groove, with the heat spreader fitting against the outer side wall of the housing.

[0010] In an optional embodiment, the depth of the groove is less than or equal to the thickness of the heat spreader.

[0011] In an optional embodiment, an insulating element is provided between the inner wall of the housing and the bare battery cell.

[0012] In an optional embodiment, the housing includes multiple sidewalls and a bottom wall connected to the sidewalls, the sidewalls and the bottom wall surrounding and forming the cavity, and a temperature distribution plate is provided on both the sidewalls and the bottom wall.

[0013] In an optional embodiment, the cover plate is provided with a positive electrode post and a negative electrode post, and the bare cell includes a positive electrode sheet, a negative electrode sheet and a separator. The positive electrode sheet, the separator, and the negative electrode sheet are stacked and wound together. The positive electrode sheet is electrically connected to the positive electrode post, and the negative electrode sheet is electrically connected to the negative electrode post.

[0014] In an optional embodiment, a positive electrode tab is connected to the side of the positive electrode plate near the cover plate, and a negative electrode tab is provided on the side of the negative electrode plate near the cover plate. A positive adapter and a negative adapter are provided on the inner side of the cover plate. The positive adapter is electrically connected to the positive electrode post, the negative adapter is electrically connected to the negative electrode post, the positive electrode tab is electrically connected to the positive adapter, and the negative electrode tab is electrically connected to the negative adapter.

[0015] In an optional embodiment, the cover plate is also provided with an explosion-proof valve.

[0016] In an optional embodiment, the cover plate is further provided with a liquid injection hole, and a sealing element is provided on the liquid injection hole.

[0017] Secondly, this utility model provides a battery pack, including the battery cells described in any of the foregoing embodiments.

[0018] The beneficial effects of the battery cell and battery pack provided in this embodiment of the invention include:

[0019] The battery cell of this invention includes a housing and a cover plate. A cavity is provided inside the housing. An opening is provided at one end of the housing. A bare battery cell is housed within the cavity. A heat spreader is provided on the side wall of the housing. A cavity is provided within the heat spreader. A phase change material is contained within the heat spreader. The cover plate is located at the opening end and is connected to the housing to seal the cavity. By providing a heat spreader on the battery cell housing, and filling the heat spreader with phase change material, when the battery cell is operating, its temperature rises. The phase change material within the heat spreader undergoes a phase change to absorb heat, thereby reducing the temperature of the battery cell during use. This prevents shortened battery cell life due to heat accumulation and prevents thermal runaway caused by excessively high battery temperature. The battery cell in this battery pack can absorb the heat generated during use, reducing the battery cell temperature, increasing battery cell life, and preventing battery thermal runaway. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the battery cell from a first-view perspective provided in this embodiment;

[0022] Figure 2 This is a schematic diagram of the battery cell from a second perspective provided in this embodiment;

[0023] Figure 3 for Figure 2 Enlarged view of part A in the middle;

[0024] Figure 4 for Figure 2 Enlarged view of section B in the middle.

[0025] Icons: 100-cell; 10-casing; 11-cavity; 12-bare cell; 13-heat spreader; 131-cavity; 20-cover plate; 21-positive terminal; 22-negative terminal; 23-explosion-proof valve; 24-filling hole; 241-seal; 25-positive adapter plate; 26-negative adapter plate. Detailed Implementation

[0026] 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, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0029] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0030] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0031] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.

[0032] First Embodiment

[0033] Please refer to Figure 1 and Figure 2 The battery cell 100 provided in this embodiment includes a housing 10 and a cover plate 20. A cavity 11 is provided inside the housing 10. A bare battery cell 12 is housed within the cavity 11. A heat spreader 13 is provided on the side wall of the housing 10. A cavity 131 is provided inside the heat spreader 13. A phase change material is housed within the cavity 131. The cover plate 20 is located at one end of the opening. The cover plate 20 is connected to the housing 10 to seal the cavity 11.

[0034] Understandably, the housing 10 and the cover plate 20 are connected to form a closed cavity 11, which is used to house and protect the bare battery cell 12. By providing a heat spreader 13 on the housing 10, the heat generated by the bare battery cell 12 during operation can be transferred from the housing 10 to the heat spreader 13. The heat spreader 13 is made of a thermally conductive material, such as silicone. The heat spreader 13 can quickly and evenly transfer and disperse the heat from the housing 10, resulting in a uniform temperature for the battery cell 100 and preventing localized overheating. By providing a phase change material within the heat spreader 13, when the battery cell 100 is operating, the phase change material within the heat spreader 13 undergoes a phase change, thereby absorbing the heat generated by the bare battery cell 12 during operation.

[0035] It's easy to understand that phase change materials (PCMs) are substances that change their state of matter and provide heat while maintaining a constant temperature. The process of changing physical properties is called a phase change process, during which the PCM absorbs or releases a large amount of heat. Taking solid-liquid phase change as an example, when a PCM is heated to its melting temperature, it undergoes a solid-to-liquid phase change. During melting, the PCM absorbs and stores a large amount of heat. In this embodiment, the PCM primarily uses a solid-to-liquid or liquid-to-gas phase change. This process absorbs a large amount of heat, preventing the cell 100 from overheating during operation, improving its lifespan, and avoiding battery thermal runaway.

[0036] The phase change material in this embodiment can be an inorganic phase change material, such as crystalline hydrated salts or molten salts. Alternatively, the phase change material can be an organic phase change material, such as paraffin wax, acetic acid, and other organic compounds. As long as the phase change material can absorb the heat generated by the battery cell 100 during operation, this invention does not limit the specific type of phase change material.

[0037] Please refer to Figure 2 and Figure 3 Specifically, a groove is formed on the outer side wall of the housing 10. The heat spreader 13 is embedded in the groove. The heat spreader 13 is in contact with the outer side wall of the housing 10. It can be understood that the groove increases the contact area between the housing 10 and the heat spreader 13, thereby improving the heat transfer efficiency between the housing 10 and the heat spreader 13.

[0038] Furthermore, the depth of the groove is less than or equal to the thickness of the heat spreader 13. It is understood that in this embodiment, the heat spreader 13 has a flat plate structure. When the heat spreader 13 is placed in the groove, one side of the heat spreader 13 is in contact with the bottom surface of the groove; the other side of the heat spreader 13 is flush with or protrudes from the outer side wall of the housing 10. It is understood that the heat spreader 13 is located on the outer side of the housing 10. When multiple battery cells 100 are installed in the battery pack, the battery cells 100 are in contact with each other. That is, on two adjacent battery cells 100, the heat spreader 13 of one battery cell 100 is in contact with the heat spreader 13 of the other battery cell 100. This not only enables uniform temperature transfer of a single battery cell 100, but also enables uniform temperature of multiple battery cells 100 throughout the entire battery pack.

[0039] Optionally, in this embodiment, the groove is provided on the outer side wall of the housing 10. That is, a groove is directly made on the outer side of the housing 10. In other embodiments, a boss can also be provided on the outer side wall of the housing 10, and a groove can be made on the boss, that is, a frame structure is formed on the outer side wall of the housing 10 for fixing the heat spreader 13. As long as it is possible to embed the heat spreader 13 into the housing 10, the present invention does not limit the specific position and structure of the groove.

[0040] Furthermore, the housing 10 includes multiple sidewalls and a bottom wall connected to the sidewalls. It is understood that the housing 10 has a cylindrical structure. The sidewalls and bottom wall surround and form a cavity 11. Temperature distribution plates 13 are provided on both the sidewalls and the bottom wall. Specifically, in this embodiment, the housing 10 has a rectangular cylindrical structure, including four sidewalls and one bottom wall. The four sidewalls and the bottom wall are connected perpendicularly to each other. Correspondingly, in this embodiment, the battery cell 100 includes five temperature distribution plates 13. The five temperature distribution plates 13 are respectively disposed on the sidewalls and the bottom wall, and the area of ​​the temperature distribution plates 13 accounts for more than 90% of the area of ​​the sidewalls and the bottom wall, respectively. It is understood that the temperature distribution plates 13 can cover most of the surface of the housing 10, achieving uniform temperature distribution of the housing 10, and also improving the heat absorption efficiency of the phase change material, preventing the battery cell 100 from overheating during operation.

[0041] Please refer to Figure 2 In this embodiment, an insulating element is provided between the inner wall of the housing 10 and the bare battery cell 12. It can be understood that the insulating element wraps around the bare battery cell 12, so that the bare battery cell 12 is insulated from the housing 10, and avoids the bare battery cell 12 from coming into contact with the external environment and causing a short circuit.

[0042] Please refer to Figure 1 and Figure 2 Specifically, the cover plate 20 is provided with a positive electrode post 21 and a negative electrode post 22. The positive electrode post 21 and the negative electrode post 22 are used for external electrical connection. The bare battery cell 12 includes a positive electrode sheet, a negative electrode sheet, and a separator. In this embodiment, the positive electrode sheet, the separator, and the negative electrode sheet are stacked and wound together. The positive electrode sheet is electrically connected to the positive electrode post 21. The negative electrode sheet is electrically connected to the negative electrode post 22.

[0043] Furthermore, a positive electrode tab is connected to the side of the positive electrode plate near the cover plate 20. A negative electrode tab is provided on the side of the negative electrode plate near the cover plate 20. A positive adapter 25 and a negative adapter 26 are provided on the inner side of the cover plate 20. The positive adapter 25 is electrically connected to the positive terminal 21. The negative adapter 26 is electrically connected to the negative terminal 22. It can be understood that the positive terminal 21 and the negative terminal 22 are located on the outer side of the cover plate 20. The positive adapter 25 and the negative adapter 26 are located on the inner side of the cover plate 20. The positive electrode tab is connected to the positive adapter 25, and thus the positive electrode tab is connected to the positive terminal 21. The negative electrode tab is connected to the negative adapter 26, and thus the negative electrode tab is connected to the negative terminal 22.

[0044] Please refer to Figure 1 and Figure 2 In this embodiment, an explosion-proof valve 23 is also provided on the cover plate 20. It is understood that during battery charging, the electrolyte inside the cell 100 undergoes chemical changes, generating a certain amount of gas. If the charging speed is too fast or the charging voltage is too high, the gas in the electrolyte will increase rapidly, causing a sudden increase in internal pressure of the cell 100. The pressure release mechanism of the explosion-proof valve 23 will automatically activate when the internal pressure of the battery reaches a certain value, opening the valve to release excess gas into the external environment, thereby relieving the internal pressure of the battery and preventing an explosion accident caused by excessive pressure.

[0045] Please refer to Figure 1 , Figure 2 and Figure 4 Furthermore, the cover plate 20 is also provided with an injection hole 24 for injecting electrolyte into the cell 100. A sealing element 241 is provided on the injection hole 24. Specifically, in this embodiment, the sealing element 241 is a sealing pin. It is understood that after injecting electrolyte into the cell 100, the sealing pin is inserted into the injection hole 24 and welded to seal the injection hole 24.

[0046] Second embodiment

[0047] This embodiment provides a battery pack, which includes the battery cell 100, thermal management system, and battery management system described in the first embodiment above. The thermal management system is used to monitor and control the temperature of the battery cell 100. The battery management system is used to monitor and control the operating status of the battery cell 100, such as its charge level. Specifically, the battery pack contains multiple battery cells 100. The multiple battery cells 100 are arranged side by side and are all fixedly connected to the housing 10 of the battery pack.

[0048] The beneficial effects of the battery cell 100 in the battery pack provided by this embodiment of the present invention include:

[0049] The battery cell 100 of this utility model includes a housing 10 and a cover plate 20. A cavity 11 is provided inside the housing 10. An opening is provided at one end of the housing 10. A bare battery cell 12 is housed within the cavity 11. A heat spreader 13 is provided on the side wall of the housing 10. A cavity 131 is provided inside the heat spreader 13. A phase change material is housed within the cavity. The cover plate 20 is located at one end of the opening. The cover plate 20 is connected to the housing 10 to seal the cavity 11. By providing a heat spreader 13 on the housing 10 of the battery cell 100, and filling the heat spreader 13 with phase change material, when the battery cell 100 is working, the temperature of the battery cell 100 rises. The phase change material in the heat spreader 13 undergoes a phase change to absorb heat, which can reduce the temperature of the battery cell 100 during use, avoiding a shortened lifespan due to heat accumulation and preventing thermal runaway caused by excessively high temperatures. The battery cell 100 in this battery pack can absorb the heat generated during use, reduce the temperature of the battery cell 100, improve the service life of the battery cell 100, and prevent battery thermal runaway.

[0050] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.

Claims

1. A battery cell, characterized in that, include: The housing has a cavity inside, an opening at one end, a bare battery cell inside the cavity, a heat spreader on the side wall of the housing, a cavity inside the heat spreader, and a phase change material inside the cavity. A cover plate is disposed at one end of the opening and is connected to the housing to close the cavity.

2. The battery cell according to claim 1, characterized in that, A groove is provided on the outer side wall of the housing, and the heat spreader is embedded in the groove, with the heat spreader fitting against the outer side wall of the housing.

3. The battery cell according to claim 2, characterized in that, The depth of the groove is less than or equal to the thickness of the heat spreader.

4. The battery cell according to claim 1, characterized in that, An insulating element is provided between the inner wall of the housing and the bare battery cell.

5. The battery cell according to claim 1, characterized in that, The housing includes multiple side walls and a bottom wall connected to the side walls. The side walls and the bottom wall surround and form the cavity. A temperature equalization plate is provided on both the side walls and the bottom wall.

6. The battery cell according to claim 1, characterized in that, The cover plate is provided with a positive electrode post and a negative electrode post. The bare cell includes a positive electrode plate, a negative electrode plate and a separator. The positive electrode plate, the separator, and the negative electrode plate are stacked and wound together. The positive electrode plate is electrically connected to the positive electrode post and the negative electrode plate is electrically connected to the negative electrode post.

7. The battery cell according to claim 6, characterized in that, The positive electrode plate is connected to a positive electrode tab on the side near the cover plate, and the negative electrode plate is provided with a negative electrode tab on the side near the cover plate. A positive adapter plate and a negative adapter plate are provided on the inner side of the cover plate. The positive adapter plate is electrically connected to the positive electrode post, the negative adapter plate is electrically connected to the negative electrode post, the positive electrode tab is electrically connected to the positive adapter plate, and the negative electrode tab is electrically connected to the negative adapter plate.

8. The battery cell according to claim 1, characterized in that, An explosion-proof valve is also installed on the cover plate.

9. The battery cell according to claim 1, characterized in that, The cover plate is also provided with a liquid injection hole, and a sealing element is provided on the liquid injection hole.

10. A battery pack, characterized in that, Includes the battery cell described in any one of claims 1-9.

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