Battery cell, battery and battery pack

Abstract

The utility model discloses a battery cell, a battery and a battery pack, and belongs to the field of lithium batteries. According to the battery cell disclosed by the utility model, the battery cell is provided with two large surfaces which are oppositely arranged, and the surface areas of the large surfaces are larger than the surface areas of other side surfaces of the battery cell; and a heat insulation layer is sprayed on the large surface of at least one battery cell. In the scheme, the heat insulation layer is sprayed on the large surface of the battery cell and is combined with the battery cell more tightly, so that the heat diffusion of the module can be slowed down more effectively, and the heat transfer between the battery cells is isolated. In addition, in the battery pack assembling process, the procedure step of placing a heat insulation layer is reduced, and the battery pack assembling efficiency is improved.

Description

Technical Field

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

[0002] With the surge in global demand for renewable energy and electric vehicles, lithium-ion batteries, as a core energy storage technology, have received unprecedented attention regarding their safety and thermal performance. In the construction of lithium-ion batteries, the battery cell has become the preferred choice for electric vehicles, energy storage systems, and other fields due to its high energy density, good thermal management, and ease of mass production. However, lithium-ion batteries may face the risk of thermal runaway under extreme conditions.

[0003] During thermal runaway, the rapid accumulation of heat inside the battery can cause the cell casing temperature to rise sharply. The softening and melting of the casing may not only lead to rapid failure and cracking of the casing structure, but also cause the high-temperature and high-pressure gas generated inside the battery to escape in a disorderly manner, which seriously affects the overall safety and performance.

[0004] To prevent thermal runaway, thermal insulation layers are typically installed between battery cells, allowing internal heat to be dissipated through a cooling layer or released via an explosion-proof valve. However, existing thermal insulation layers are usually independent structural components, such as aerogel pads. Independently installed thermal insulation layers can affect both battery assembly efficiency and insulation effectiveness. Utility Model Content

[0005] This invention provides a battery cell, a battery, and a battery pack to solve the problem that existing heat insulation layers affect battery assembly efficiency and heat insulation effect.

[0006] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0007] A battery cell has two large surfaces arranged opposite each other, the surface area of ​​which is larger than the surface area of ​​the other sides of the battery cell; at least one of the large surfaces of the battery cell is coated with a heat insulation layer with a thermal conductivity of 0.01 to 0.1 W / (m·K).

[0008] In this design, the heat insulation layer is sprayed onto the large surface of the battery cell, resulting in a tighter bond with the cell and more effectively mitigating heat diffusion within the module and isolating heat transfer between cells. Furthermore, the process of placing the heat insulation layer during battery pack assembly is reduced, improving assembly efficiency.

[0009] As a further improvement, the thickness of the insulation layer is 0.5–3 mm. This ensures that the insulation layer meets both the insulation effect and the energy density requirements of the battery pack.

[0010] As a further improvement, the thickness of the insulation layer is the same at different locations on the large surface of the battery cell. This facilitates the formation of the insulation layer and improves the efficiency of its installation.

[0011] As a further improvement, the thickness of the heat insulation layer varies at different locations on the large surface of the battery cell. The thickness of the heat insulation layer decreases from at least one edge of the large surface of the battery cell to the center of the large surface of the battery cell. During cyclic charging, the battery cell expands, and the expansion is greater closer to the center of the large surface of the battery cell. The heat insulation layer acts as a buffer, absorbing the cyclic expansion force of the battery cell.

[0012] As a further improvement, an insulating layer is also sprayed onto the outer surface of the battery cell, with the heat-insulating layer sprayed onto the side of the insulating layer away from the battery cell. The insulating layer serves an insulating function, improving the safety of the battery cell.

[0013] As a further improvement, the thickness of the insulating layer is ≥80μm.

[0014] As a further improvement, one end of the battery cell has a terminal; the end away from the terminal is the bottom surface of the battery cell, which is used to connect with the heat-conducting layer.

[0015] This utility model also provides a battery, including at least one of the aforementioned cells.

[0016] This utility model also provides a battery pack, including the aforementioned battery. The battery cells are arranged side-by-side with their large surfaces close to each other. A heat insulation layer is located between the large surfaces of adjacent cells, and the heat insulation layer is sprayed onto the large surfaces of the cells, bonding more tightly to them. This improves the heat insulation effect between the cells, allowing heat to be dissipated through the heat-conducting layer within the battery pack, preventing heat accumulation at the cells and improving the overall safety performance of the battery pack.

[0017] Other technical problems that the present invention's cell, battery, and battery pack can solve, other technical features contained in the technical solution, and the advantages brought by these technical features will be further explained in detail with reference to the accompanying drawings. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the battery cell structure;

[0019] Figure 2 In one scenario, when the insulation layer is relatively thin at the center of the large surface area of ​​the battery cell, Figure 1 Cross-sectional view of AA-type battery cell.

[0020] Label Explanation:

[0021] 11. Battery cell; 12. Terminal; 2. Insulation layer; 3. Heat insulation layer; 4. Heat conductive layer. Detailed Implementation

[0022] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0023] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate for the embodiments of this application described herein.

[0025] like Figure 1 As shown, this embodiment provides a battery cell, namely a battery cell 11. The battery cell 11 has two large surfaces arranged opposite each other, and the surface area of ​​the large surface is larger than the surface area of ​​the other side surfaces of the battery cell 11. At least one of the large surfaces of the battery cell 11 is coated with a heat insulation layer 3 with a thermal conductivity of 0.01 to 0.1 W / (m·K).

[0026] In this embodiment, the battery cell 11 is a square battery cell, and therefore has two large faces arranged opposite each other. When multiple battery cells are stacked to form a module or stacked in a box, the large faces of adjacent battery cells are stacked close to each other.

[0027] In this design, a heat insulation layer 3 is sprayed onto the large surface of the battery cell 11. The thermal conductivity of the heat insulation layer 3 is 0.01–0.1 W / (m·K), preferably 0.01–0.02 W / (m·K). For example, the heat insulation layer 3 is aerogel. The aerogel is sprayed onto the large surface of the battery cell. Compared to existing methods that place heat insulation layers independently between battery cells, the heat insulation layer 3 in this design is sprayed onto the large surface of the battery cell 11, resulting in a tighter bond with the battery cell. This effectively slows down heat diffusion within the module and isolates heat transfer between battery cells. Furthermore, the process of placing the heat insulation layer is reduced during battery pack assembly, improving battery pack assembly efficiency.

[0028] In this embodiment, a heat insulation layer 3 is sprayed on both large surfaces of the battery cell 11.

[0029] However, in other embodiments, since multiple cells 11 are stacked in the battery pack, a heat insulation layer 3 can be sprayed onto the large surface of one cell. When adjacent cells are stacked, the large surface of one cell without a heat insulation layer is placed close to the large surface of another cell with a heat insulation layer. This method can improve the efficiency of heat insulation layer application.

[0030] As a further improvement, the thickness of the heat insulation layer 3 is 0.5–3 mm. Preferably, the thickness of the heat insulation layer 3 is 1.5–2 mm, for example, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, or 2 mm. Since the heat insulation layer 3 occupies space within the battery pack, setting the thickness of the heat insulation layer 3 within this range ensures that the heat insulation layer 3 meets the heat insulation effect while also meeting the energy density requirements of the battery pack.

[0031] In one specific implementation, the thickness of the heat insulation layer 3 is the same at different locations on the large surface of the battery cell 11. This method facilitates the formation of the heat insulation layer 3 and improves the efficiency of its installation.

[0032] like Figure 2 As shown, in another embodiment, the thickness of the heat insulation layer 3 varies at different locations on the large surface of the battery cell 11. Forming the heat insulation layer 3 by spraying makes it easier to set the thickness at different locations. More specifically, the thickness of the heat insulation layer 3 decreases from at least one edge of the large surface of the battery cell 11 to the center of the large surface. In this design, the thickness of the heat insulation layer 3 is smaller near the center of the large surface. During battery cell cyclic charging, the heat insulation layer 3 acts as a buffer, absorbing the expansion force of the battery cell during cyclic charging.

[0033] It should be noted that, preferably, the front and rear edges of the large surface of the battery cell 11 ( Figure 1 The thickness of the heat insulation layer 3 is relatively large at the two edges (in the middle view direction), and gradually decreases from the edges to the center of the large surface. In this case, an opening will be formed between adjacent heat insulation layers 3 in the vertical direction or between the heat insulation layer 3 and the side of the battery cell, so as to avoid air resistance when the battery cell expands during cyclic charging.

[0034] Preferably, an insulating layer 2 is further coated on the outer surface of the battery cell 11, and a heat insulation layer 3 is coated on the side of the insulating layer 2 away from the battery cell. The thickness of the insulating layer 2 is ≥80μm. Specifically, the insulating layer 2 is a UV coating, which serves as insulation and improves the safety of the battery cell.

[0035] Additionally, one end of the battery cell 11 has a terminal 12; the end away from the terminal 12 is the bottom surface of the battery cell 11, which is used to connect with the thermal conductive layer 4. For example, when the battery cell 11 is stacked in a housing, the bottom of the housing is provided with the thermal conductive layer 4, and the bottom surface of the battery cell 11 is placed on the thermal conductive layer 4, which can effectively conduct away the heat generated by the battery cell in the event of thermal runaway, thereby cooling down and transferring the heat out of the module. Specifically, the thermal conductive layer 4 can be a heat dissipation structural adhesive or a water-cooling plate, etc.

[0036] This application also provides a battery comprising at least one of the aforementioned cells.

[0037] This application also provides a battery pack including the battery described above.

[0038] The terms "installation," "setup," "equipped with," and "connection" used herein should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0039] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. An electric cell, characterized by: The battery cell (11) has two large surfaces arranged opposite each other, the surface area of ​​which is larger than the surface area of ​​the other sides of the battery cell (11); at least one of the large surfaces of the battery cell (11) is coated with a heat insulation layer (3).

2. The battery cell according to claim 1, characterized in that: The thickness of the heat insulation layer (3) is 0.5 to 3 mm.

3. The battery cell according to claim 2, characterized in that: The thickness of the heat insulation layer (3) is the same at different positions on the large surface of the battery cell (11).

4. The battery cell according to claim 2, characterized in that: The thickness of the heat insulation layer (3) varies at different locations on the large surface of the battery cell (11).

5. The battery cell according to claim 4, characterized in that: The thickness of the insulation layer (3) decreases from at least one edge of the large surface of the battery cell (11) to the center of the large surface of the battery cell (11).

6. The battery cell according to any one of claims 1-5, characterized in that: The outer surface of the battery cell (11) is also coated with an insulating layer (2), and the heat insulation layer (3) is coated on the side of the insulating layer (2) away from the battery cell.

7. The battery cell according to claim 6, characterized in that: The thickness of the insulating layer (2) is ≥80μm.

8. The battery cell according to claim 6, characterized in that: One end of the battery cell (11) has a terminal (12); the end away from the terminal (12) is the bottom surface of the battery cell (11), which is used to connect with the heat-conducting layer (4).

9. A battery, characterized in that: It includes at least one battery cell as described in any one of claims 1-8.

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

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