Battery cell and electric device

Abstract

The utility model provides a kind of battery monomer and electric device, battery monomer includes: shell, the shell includes shell main body and cover, the shell main body forms the accommodation cavity with opening, and the cover is covered in the opening;Electrode assembly, the electrode assembly is located in the accommodation cavity;Thermal management function layer, the thermal management function layer is between the electrode assembly and the inner surface of shell main body, at 25 DEG C temperature, the thermal conductivity of the thermal management function layer is 0.015W / (mK)-0.035W / (mK). Single battery in the application can release heat well in the cycle process, so that the battery does not appear heat accumulation phenomenon in the cycle process, and when single battery is used in group, when single battery thermal runaway, it can play a blocking role, so that the battery module does not appear heat spread phenomenon.

Description

Technical Field

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

[0002] In the new energy vehicle industry, battery systems have become a key component of the vehicle's power source, undertaking all or part of the driving function; in terms of energy storage applications, battery cells are integrated into energy storage boxes or directly deployed on the user side to achieve efficient power dispatch and stable power supply.

[0003] However, due to the characteristics of the electrochemical system and limitations of operating conditions, new energy batteries are prone to localized heat accumulation during charge-discharge cycles, leading to a rapid increase in temperature and, in severe cases, thermal runaway. This problem not only significantly reduces the battery's energy efficiency, cycle life, and safety performance, but also poses a potential threat to the overall reliability of the system and the safety of people and property. Therefore, how to improve battery safety and stability through battery thermal management is a technical problem that urgently needs to be solved in battery technology. Utility Model Content

[0004] One objective of this invention is to provide a battery cell that improves the heat dissipation capacity of the battery cell, prevents thermal runaway, and enhances the stability and safety performance of the battery.

[0005] In a first aspect, this application provides a battery cell, comprising: a casing, the casing including a casing body and a cover, the casing body forming an accommodating cavity with an opening, the cover covering the opening; an electrode assembly disposed in the accommodating cavity; and a thermal management functional layer located between the electrode assembly and the inner surface of the casing body, wherein the thermal conductivity of the thermal management functional layer is 0.015 W / (m²) at a temperature of 25°C. K)-0.035W / (m K).

[0006] In this application, a thermal management functional layer is set in the single cell, and the thermal conductivity is controlled at 0.015 W / (m²). K)- 0.035W / (m When K), the individual battery cells can effectively release heat during cycling, preventing heat accumulation. Furthermore, when individual battery cells are used in a group, they can act as a barrier in the event of thermal runaway in a single cell, preventing heat propagation from the battery module.

[0007] Optionally, the thermal management functional layer is a thermally conductive layer disposed on the inner surface, and the thermally conductive layer is bonded to the inner surface of the housing body by an adhesive layer; or, the thermal management functional layer is a coating applied to the inner surface of the housing body.

[0008] Optionally, the thickness of the thermally conductive layer is 0.5mm-4mm.

[0009] Optionally, the thickness of the coating is 0.5mm-4mm.

[0010] Optionally, the coating comprises at least one of hollow microspheres, inorganic porous fillers, and nano-silica aerogel.

[0011] Optionally, the battery cell further includes a Mylar membrane for wrapping the electrode assembly, and the thermal management functional layer is disposed on the Mylar membrane.

[0012] Optionally, the Mylar membrane includes: two first insulating members, each first insulating member corresponding to a large surface of the electrode assembly, the first insulating member including a stacked insulating layer and the thermal management functional layer; a second insulating member, the second insulating member being connected to the two first insulating members respectively and corresponding to the bottom surface of the electrode assembly; and a third insulating member, the third insulating member being connected to the first insulating members and corresponding to the side surface of the electrode assembly.

[0013] Optionally, the thickness of the thermal management functional layer is 0.5mm-2mm, and the thickness of the insulating layer is 0.05mm-2mm.

[0014] Optionally, the thermal management functional layer is a functional layer formed by any one or more of aerogel, vacuum insulation board or polyurethane foam; the insulation layer is a polypropylene layer.

[0015] Secondly, this application also provides an electrical device comprising any of the battery cells described above.

[0016] Other features and advantages of the present invention will become clear from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present invention and, together with their description, serve to explain the principles of the present invention.

[0018] Figure 1 This is an exploded view of a single cell battery according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the cross-section of a single battery cell according to an embodiment of the present invention; Figure 3 This is a schematic cross-sectional view of a battery cell housing according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the unfolded Mylar membrane according to one embodiment of the present invention; Figure 5 This is a cross-sectional schematic diagram of a Mylar membrane according to an embodiment of the present invention.

[0019] Attached icon number Casing 100; Outer shell body 10; opening 11; first inner wall surface 12; second inner wall surface 13; Cover body 20; Top cover patch 30; Electrode assembly 200; core 201; positive electrode tab 202; positive electrode connecting piece 203; base plate 204; Mylar film adhesive 205; negative electrode connecting piece 206; negative electrode tab 207; tab adhesive 208; blue film 209; Thermal management functional layer 300; Mylar film 400; first insulating element 401; second insulating element 402; third insulating element 403; insulating layer 404. Detailed Implementation

[0020] The embodiments of this utility model will now be described in detail. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0021] The terms "first" and "second" in the specification and claims of this utility model may explicitly or implicitly include one or more of the features. In the description of this utility model, unless otherwise stated, "multiple" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0022] In the description of this utility model, it should be understood that the terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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.

[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] like Figures 1 to 5 As shown, the battery cell according to an embodiment of the present invention includes: a housing 100, an electrode assembly 200, and a thermal management functional layer 300.

[0025] Specifically, the outer casing 100 includes a main casing 10 and a cover. The main casing 10 forms a receiving cavity with an opening 11, and the cover closes to the opening 11. The electrode assembly 200 is disposed in the receiving cavity, and the thermal management functional layer 300 is located between the electrode assembly 200 and the inner surface of the main casing 10. At a temperature of 25°C, the thermal conductivity of the thermal management functional layer 300 is 0.015 W / (m²). K)-0.035W / (m K).

[0026] In other words, the outer casing 10 is a semi-closed cuboid aluminum shell with an opening 11. When the outer casing 100 is used in a battery, the electrode assembly 200 can be installed in the receiving space through the opening 11. After the electrode assembly 200 is installed inside the outer casing 10, a cover can be placed over the opening 11 of the outer casing 10 to seal the battery.

[0027] The thermal management functional layer 300 is located between the electrode assembly 200 and the inner surface of the housing body 10. For example, the inner surface of the housing body 10 includes two opposing first inner wall surfaces 12 and two opposing second inner wall surfaces 13. For example, the bottom of the housing body 10 is closed and the top is open. The two first inner wall surfaces 12 and the two second inner wall surfaces 13 together form an open hollow cavity. The area of ​​the first inner wall surface 12 is larger than the area of ​​the second inner wall surface 13. The cross-sectional shape of the housing body 10 can be rectangular. For another example, the two first inner wall surfaces 12 are spaced apart in the front-back direction, and the two second inner wall surfaces 13 are spaced apart in the left-right direction. The thermal management functional layer 300 can be disposed on the inner side of at least one first inner wall surface 12 near the receiving space, that is, the thermal management functional layer 300 can be located between the first inner wall surface 12 and the electrode assembly 200; similarly, the thermal management functional layer 300 can also be disposed on the inner side of at least one second inner wall surface 13 near the receiving space. By designing the position of the thermal management functional layer 300, the optimal location for balancing heat insulation and heat dissipation can be selected. For example, by simultaneously setting the thermal management functional layer 300 on the inner surfaces of each first inner wall surface 12 and each second inner wall surface 13, multi-directional heat insulation and heat dissipation balance can be achieved for the circumference of the electrode assembly 200 after it is installed in the housing. The bottom of the outer casing 10 can be opposite to the opening 11, and the bottom surface can be connected to the first inner wall surface 12 and the second inner wall surface 13 respectively. Figure 2 As shown, in the cross-section along the direction perpendicular to the height of the battery, the outermost layer is the outer casing 10, the inner side of the outer casing 10 is provided with a thermal management functional layer 300, and the inner side of the thermal management functional layer 300 is provided with an electrode assembly 200.

[0028] In addition, at a temperature of 25°C, the thermal conductivity of the thermal management functional layer 300 is 0.015 W / (m²). K)- 0.035W / (m K), which enables the thermal management functional layer 300 to have both thermal insulation and thermal conductivity, thus achieving synergistic optimization of thermal insulation and heat dissipation performance.

[0029] Therefore, according to the embodiment of the present invention, the housing 100 has a thermal management functional layer 300 disposed between the housing body 10 and the electrode assembly 200, and the thermal conductivity of the thermal management functional layer 300 is 0.015 W / (m²). K)- 0.035W / (m K) can meet the requirements of heat insulation, improve battery safety, prevent battery thermal runaway, and meet the battery heat dissipation requirements.

[0030] Optionally, the orthographic projection of the thermal management functional layer 300 corresponding to the first inner wall surface 12 onto the first inner wall surface 12 is located inside the first inner wall surface 12; or, the orthographic projection of the thermal management functional layer 300 corresponding to the second inner wall surface 13 onto the second inner wall surface 13 is located inside the second inner wall surface 13. That is, in this embodiment, the area of ​​the thermal management functional layer 300 disposed on the inner side of the first inner wall surface 12 can be slightly smaller than the first inner wall surface 12, and the area of ​​the thermal management functional layer 300 disposed on the inner side of the second inner wall surface 13 can be slightly smaller than the second inner wall surface 13. For example, the shapes of the first inner wall surface 12 and the second inner wall surface 13 are both rectangular, and the thermal management functional layer 300 is a rectangular single layer. In this embodiment, by using a thermal management functional layer 300 with a smaller area and an outer edge that does not exceed the outer edge of the outer shell body 10, it is not only convenient to set up the thermal management functional layer 300, for example, easy to paste, but also avoids occupying too much internal space of the outer shell body 10 due to an excessively large area.

[0031] According to one embodiment of this utility model, the thermal management functional layer 300 is a thermally conductive layer disposed on the inner surface, and the thermally conductive layer is bonded to the inner surface of the outer casing 10 by an adhesive layer. That is, the thermal management functional layer 300 is bonded to the inner surface of the outer casing 10, for example, by adhesive bonding to the first inner wall surface 12. In use, the thermal management functional layer 300 can be bonded to the inner wall of the outer casing 10 before the electrode assembly 200 is installed into the outer casing 10, and then the electrode assembly 200 is installed into the outer casing 10. Subsequently, the thermal management functional layer 300 can be located between the inner wall of the outer casing 10 and the electrode assembly 200. In this embodiment, the use of adhesive bonding has the advantage of ease of operation.

[0032] In some specific embodiments of this utility model, the thermal management functional layer 300 is a coating applied to the inner surface of the outer casing 10. That is, the thermal management functional layer 300 is coated on the inner surface of the outer casing 10, for example, on the first inner wall surface 12. In this embodiment, the thermal management functional layer 300 can be applied to the inner surface of the outer casing 10 as a coating to form the thermal management functional layer 300. Utilizing this coating method improves the convenience of battery manufacturing. Furthermore, by applying a functional coating to the inner surface of the outer casing 10, the energy density of the battery can be increased while meeting the battery's thermal management requirements, and it is also easy to implement, reducing manufacturing costs.

[0033] According to one embodiment of this utility model, the thickness of the thermally conductive layer is 0.5mm-4mm. That is, when the thermal management functional layer 300 is attached to the inner side of the outer casing 10, for example, to the inner surface of the first inner wall 12, the thickness of the thermal management functional layer 300 can be 0.5mm-4mm, such as 0.5mm, 1.5mm, 2mm, 3mm, or 4mm. This avoids excessive thickness that would occupy too much internal space of the outer casing 10. Furthermore, it ensures that the temperature control component has both heat insulation and thermal conductivity capabilities. In this application, by attaching the thermally conductive layer to the inner surface of the outer casing and controlling the thickness of the thermally conductive layer to 0.5mm-4mm, the thermal management requirements of the battery are met without affecting the battery's energy density.

[0034] In some specific embodiments of this utility model, the thickness of the coating is 0.5mm-4mm. That is to say, when the coating method is adopted, the thickness of the thermal management functional layer 300 is 0.5mm-2mm, for example, the thickness of the thermal management functional layer 300 is 0.5mm, 1.5mm, 1.8mm or 2mm, etc., which not only facilitates coating, but also ensures that the temperature control component has both heat insulation capability and a certain thermal conductivity capability.

[0035] According to one embodiment of this utility model, the coating includes at least one of hollow microspheres, inorganic porous fillers, and nano-silica aerogel. That is, the thermal management functional layer 300 includes at least one of hollow microspheres, inorganic porous fillers, and nano-silica aerogel. In this embodiment, the coating material can be hollow microspheres, inorganic porous fillers, and nano-silica aerogel, which can ensure that the temperature control component has both thermal insulation and a certain degree of thermal conductivity.

[0036] In some specific embodiments of this utility model, such as Figure 5 As shown, the battery cell also includes a Mylar membrane 400, which is used to wrap the electrode assembly 200, and a thermal management functional layer 300 is disposed on the Mylar membrane 400. In this application, by combining the thermal management functional layer 300 and the Mylar membrane 400 into one piece, mass production can be facilitated, and the production efficiency can be improved.

[0037] Optionally, the Mylar membrane 400 includes a thermal management functional layer 300 and an insulating layer 404 stacked together. At a temperature of 25°C, the thermal management functional layer 300 has a thermal conductivity of 0.015 W / (m²). K)- 0.035W / (m In other words, the Mylar membrane 400 includes a thermal management functional layer 300 and an insulating layer 404. The thermal management functional layer 300 and the insulating layer 404 can be stacked. For example, the thermal management functional layer 300 and the insulating layer 404 can each adopt a layered structure. After assembling the various structures into a single cell, the thermal management functional layer 300 is close to the outer shell 10, and the insulating layer 404 is close to the electrode assembly 200. It can be understood that in the Mylar membrane 400, by combining the thermal management functional layer 300 and the insulating layer 404, the prepared Mylar membrane 400 has both insulation and heat insulation and heat conduction functions, which can provide heat insulation and heat conduction functions for the electrode assembly 200, and can significantly improve the production efficiency and manufacturing efficiency during the manufacturing of single cells.

[0038] According to one embodiment of this utility model, the Mylar membrane 400 includes: two first insulating members 401, a second insulating member 402, and a third insulating member 403. Each first insulating member 401 corresponds to a large surface of the electrode assembly 200. The first insulating member 401 includes a stacked insulating layer 404 and a thermal management functional layer 300. The second insulating member 402 is connected to both first insulating members 401 and corresponds to the bottom surface of the electrode assembly 200. The third insulating member 403 is connected to the first insulating member 401 and corresponds to the side surface of the electrode assembly 200. That is, a thermal management functional layer 300 can be provided on one side of the large surface of the single cell, while no thermal management functional layer 300 is provided on the bottom, top, and narrow surfaces of the single cell, which can provide local heat insulation and heat conduction functions for the single cell.

[0039] According to one embodiment of this utility model, the thickness of the thermal management functional layer 300 is 0.5mm-2mm, and the thickness of the insulating layer 404 is 0.05mm-2mm. That is, the thickness of the thermal management functional layer 300 in the Mylar film 400 is 0.5mm-2mm, for example, the thickness of the thermal management functional layer 300 is 0.5mm, 0.8mm, 1.0mm, 1.5mm, or 2mm, etc.; the thickness of the insulating layer 404 in the Mylar film 400 is 0.05mm-2mm, for example, the thickness of the insulating layer 404 is 0.05mm, 0.08mm, 0.1mm, 0.3mm, 0.5mm, 0.8mm, 1.0mm, 1.5mm, or 2mm, etc. In this embodiment, by adopting the thickness within the above-mentioned numerical range, it is possible to ensure heat insulation, heat conduction, and insulation effects while avoiding affecting the internal space of the battery and thus the energy density of the battery.

[0040] In some specific embodiments of this utility model, the thermal management functional layer 300 is a functional layer formed by any one or more of aerogel, vacuum insulation board, or polyurethane foam; the insulation layer 404 is a polypropylene layer. That is, the thermal management functional layer 300 in the Mylar membrane 400 can be made of materials such as aerogel, vacuum insulation board, and polyurethane foam, possessing good thermal insulation and certain thermal conductivity. The insulation layer 404 in the Mylar membrane 400 can be made of conventional polypropylene material, which not only provides insulation but can also be composited with the thermal management functional layer 300.

[0041] Optionally, based on the heat-fusion properties, insulation and mechanical protection of Mylar membrane 400, its surface can be supplemented with structural innovations (such as porous, concave-convex interlocking, double-layer through holes) and process optimization to continuously improve battery safety and energy efficiency.

[0042] Optionally, such as Figure 1 As shown, the electrode assembly 200 of a single cell may include a core 201, a positive electrode tab 202, a positive electrode connecting piece 203, a cover 20, a top cover patch 30, a negative electrode connecting piece 206, a negative electrode tab 207, and a tab adhesive 208. The electrode assembly 200 may be provided with a Mylar film 400, a blue film 209, a bottom support plate 204, and a Mylar film coating adhesive 205, etc.

[0043] This utility model also provides an electrical device, including a battery cell of any of the above embodiments. Since the battery cell of this utility model has advantages such as high assembly efficiency and high safety, the electrical device of this utility model also has the same advantages, which will not be elaborated here.

[0044] In summary, in this embodiment of the present invention, the assembly efficiency of the thermal management functional layer 300 during the manufacturing process can be improved by using a variety of methods, such as a separately set thermal management functional layer 300, a pasted thermal management functional layer 300, a coated thermal management functional layer 300, or a Mylar film 400 formed by combining it with the insulating layer 404.

[0045] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A battery cell, characterized in that, include: The outer casing (100) includes an outer casing body (10) and a cover (20), the outer casing body (10) forming an accommodating cavity with an opening (11), and the cover (20) covering the opening (11). Electrode assembly (200), the electrode assembly (200) being disposed in the accommodating cavity; A thermal management functional layer (300) is located between the electrode assembly (200) and the inner surface of the outer casing (10). At a temperature of 25°C, the thermal conductivity of the thermal management functional layer (300) is 0.015 W / (m²). K)-0.035W / (m K).

2. The battery cell according to claim 1, characterized in that, The thermal management functional layer (300) is a thermally conductive layer disposed on the inner surface, and the thermally conductive layer is bonded to the inner surface of the outer shell body (10) by an adhesive layer; or, the thermal management functional layer (300) is a coating applied to the inner surface of the outer shell body (10).

3. The battery cell according to claim 2, characterized in that, The thickness of the thermally conductive layer is 0.5mm-4mm.

4. The battery cell according to claim 2, characterized in that, The thickness of the coating is 0.5mm-4mm.

5. The battery cell according to claim 3, characterized in that, The coating comprises one of hollow microspheres, inorganic porous fillers, and nano-silica aerogel.

6. The battery cell according to claim 1, characterized in that, Also includes: Mylar membrane (400) is used to encapsulate the electrode assembly (200), and the thermal management functional layer (300) is disposed on the Mylar membrane (400).

7. The battery cell according to claim 6, characterized in that, The Mylar membrane (400) comprises: Two first insulating elements (401), each first insulating element (401) corresponding to one large surface of the electrode assembly (200), the first insulating element (401) including a stacked insulating layer (404) and the thermal management functional layer (300). The second insulating element (402) is connected to the two first insulating elements (401) respectively and corresponds to the bottom surface of the electrode assembly (200); A third insulating element (403) is connected to the first insulating element (401) and corresponds to the side of the electrode assembly (200).

8. The battery cell according to claim 7, characterized in that, The thickness of the thermal management functional layer (300) is 0.5mm-2mm, and the thickness of the insulating layer (404) is 0.05mm-2mm.

9. The battery cell according to claim 8, characterized in that, The thermal management functional layer (300) is a functional layer formed of aerogel, vacuum insulation board or polyurethane foam; the insulation layer (404) is a polypropylene layer.

10. An electrical appliance, characterized in that, Includes the battery cell described in any one of claims 1-9.

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