Battery cells and batteries

Abstract

This utility model provides a battery cell and a battery, relating to the field of battery technology. The battery cell provided by this utility model, through a fire-extinguishing layer disposed between the large surface of the core and the inner wall of the casing, automatically absorbs heat and cools the large surface of the core when the core is in a state of rapid temperature rise or high temperature. This reduces the temperature rise of the large surface of the core, thereby achieving individual cooling of a single core. This reduces heat transfer between the large surfaces of adjacent cores, avoids temperature transfer and expansion between adjacent cores, and consequently prevents thermal runaway of the battery. It also improves the battery's electrical performance and extends the battery's performance degradation period.

Description

Technical Field

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

[0002] Currently, in order to prevent thermal runaway fires from spreading between different PACKs within the storage compartment and causing uncontrollable consequences, the fire protection solutions adopted by large storage projects in the industry are generally PACK-level fire detection and compartment-level fire detection. After fire linkage, an alarm is triggered and ventilation is exhausted, or PACK-level or compartment-level fire extinguishing and explosion disposal is activated.

[0003] In related technologies, PACKs often use combustible gas and smoke temperature composite detectors for detection. Although such detectors can provide high accuracy and fast response to alarms, they can only detect and alarm after the battery has released a large amount of smoke or combustible gas. At this time, a large amount of smoke or combustible gas has been released from the cell, making it impossible to cool down and extinguish the individual cell in time, which can easily lead to thermal runaway between battery packs. Utility Model Content

[0004] The purpose of this invention is to provide a battery cell and battery that can cool individual battery cells individually, thereby reducing heat transfer between the large surfaces of adjacent battery cells.

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

[0006] In a first aspect, this utility model provides a battery cell, wherein the battery cell has a large surface area on both a first side and a second side opposite to each other, and the battery cell includes:

[0007] A housing and a core, wherein the core is housed inside the housing and the core has two large core surfaces, which are respectively disposed on a first side and a second side opposite to each other.

[0008] A fire extinguishing layer is located between the large surface of the core and the inner wall of the housing. When the battery cell is in a high-temperature state, the fire extinguishing layer is used to automatically absorb heat and cool the battery cell.

[0009] In an optional embodiment, the fire extinguishing layer contains a fire extinguishing agent. When the battery cell is at a high temperature, the fire extinguishing agent automatically vaporizes and absorbs heat to cool the battery cell.

[0010] In an optional embodiment, the extinguishing agent includes perfluorohexanone, and the perfluorohexanone is combined with a polymeric binder to form the extinguishing layer.

[0011] In an optional embodiment, the extinguishing agent is coated onto the large surface of the core and / or the inner wall of the housing to form the extinguishing layer.

[0012] In an optional embodiment, the fire extinguishing layer is bonded to the large surface of the core or the inner wall of the housing.

[0013] In an optional embodiment, the center of the fire extinguishing layer is coaxially arranged with the center of the large surface of the core, and the fire extinguishing layer covers at least 1 / 3 of the area of ​​the large surface of the core.

[0014] In an optional embodiment, the thickness of the fire extinguishing layer is less than the distance between the large surface of the core and the inner wall of the shell;

[0015] The thickness of the fire extinguishing layer is less than 0.5 mm.

[0016] In an optional embodiment, the fire extinguishing layer is provided between the large surface of the core located on the first side and / or the large surface of the core located on the second side and the inner wall of the housing.

[0017] In an optional embodiment, the shape of the fire extinguishing layer includes at least one of the following: rectangular, circular, and arc-shaped.

[0018] Secondly, this utility model provides a battery, including the battery cell described in any of the foregoing embodiments.

[0019] The beneficial effects of the battery cell and battery provided in this embodiment of the present invention include:

[0020] By setting a fire extinguishing layer between the large surface of the core and the inner wall of the casing, when the cell is in a state of rapid temperature rise or high temperature, the fire extinguishing layer automatically absorbs heat and cools the large surface of the cell, reducing the temperature rise of the large surface of the cell. This achieves individual cooling of a single cell, thereby reducing heat transfer between the large surfaces of adjacent cells, avoiding temperature transfer and expansion between adjacent cells, and preventing the occurrence of battery thermal runaway in a timely manner. It can also improve the battery's electrical performance and extend the battery's performance degradation period. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is a side view of the battery cell provided in this embodiment;

[0023] Figure 2 This is a front view of the battery cell provided in this embodiment;

[0024] Figure 3This is a partial cross-sectional view of the battery cell provided in this embodiment;

[0025] Figure 4 This is an exploded view of a battery cell provided in this embodiment;

[0026] Figure 5 An exploded view of another type of battery cell provided in this embodiment;

[0027] Figure 6 This is an exploded view of another type of battery cell provided in this embodiment.

[0028] Icons: 100-Battery cell; 101-First side; 102-Second side; 103-Main surface of battery cell; 110-Casing; 120-Core; 121-Main surface of core; 130-Fire extinguishing layer; 140-Top cover. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] 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.

[0033] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0034] 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.

[0035] The following describes in detail the overall structure, working principle, and technical effects of the battery cell 100 and battery provided by this utility model through embodiments and in conjunction with the accompanying drawings.

[0036] Please refer to Figures 1-2 The battery cell 100 provided by this utility model is used in batteries and can cool down batteries that are in a high-temperature state or an open flame state.

[0037] The battery proposed in this utility model can be a single cell or a battery module; wherein, a single cell includes a cell 100; wherein, a battery module includes multiple electrically connected cells 100 and a housing, and the multiple cells 100 are encapsulated in the housing.

[0038] In this embodiment, the battery cell 100 is a square battery with a flat or cuboid shape. Therefore, there are two opposing planes with the largest area on the first side 101 and the second side 102 of the battery cell 100, namely the large surface 103 of the battery cell.

[0039] It is understandable that these two large cell surfaces 103 play an important role in battery design, thermal management, and system integration. Therefore, this invention targets the two large cell surfaces 103 to absorb heat and cool down the cell 100.

[0040] Please refer to Figures 1-3 The present invention proposes a battery cell 100, wherein the battery cell 100 has a large surface 103 on both the first side 101 and the second side 102 opposite to each other, and the battery cell 100 includes:

[0041] The housing 110 and the core 120 are housed inside the housing 110. The core 120 has two core surfaces 121, which are respectively disposed on the first side 101 and the second side 102 opposite to each other.

[0042] Fire extinguishing layer 130 is located between the large surface 121 of the core and the inner wall of the housing 110. When the battery cell 100 is in a high temperature state, the fire extinguishing layer 130 is used to absorb heat and cool down the automatic battery cell 100.

[0043] It is understood that the battery cell 100 has a large surface 103 on the opposite first side 101 and second side 102, and the winding core 120 also has a large surface 121 on the opposite first side 101 and second side 102 of the battery cell 100. The large surface 121 and the large surface 103 are located on the same side. In the related technology, the temperature transfer and expansion between adjacent battery cells 100 mainly start from the large surface 103. Therefore, this application provides a fire extinguishing layer 130 between the large surface 121 of the core and the inner wall of the casing 110. When the cell 100 is in a state of rapid temperature rise or high temperature, the fire extinguishing layer 130 automatically absorbs heat and cools the large surface 103 of the cell, reducing the temperature rise of the large surface 103 of the cell. This achieves individual cooling of a single cell 100, thereby reducing heat transfer between the large surfaces 103 of adjacent cells 100, avoiding temperature transfer and expansion between adjacent cells 100, and preventing the occurrence of battery thermal runaway in a timely manner. It can also improve the battery's electrical performance and prolong the battery's performance degradation.

[0044] In this embodiment, the battery cell 100 includes a housing 110, a winding core 120, and a top cover 140.

[0045] Please refer to Figures 1-2 The battery cell 100 has a large surface 103 on both the first side 101 and the second side 102.

[0046] In this embodiment, please refer to Figures 3-5 A flat core 120 is formed by stacking the positive electrode, negative electrode, and separator through a winding process. The core 120 has tabs that connect to the electrode posts on the top cover 140. The core 120 and the top cover 140 are connected to form a bare battery cell 100. The bare battery cell 100 is then placed into a housing, with the core 120 housed within the inner wall of the housing 110. The top cover 140 is then sealed to the open end of the housing 110. The core 120 has two large core surfaces 121, which are respectively located on a first side surface 101 and a second side surface 102.

[0047] In this embodiment, the battery cell 100 includes a fire extinguishing layer 130.

[0048] In this embodiment, please refer to Figure 3 The fire extinguishing layer 130 is located between the large surface 121 of the core and the inner wall of the housing 110. When the battery cell 100 is in a high temperature state, the fire extinguishing layer 130 is used to absorb heat and cool down the automatic battery cell 100.

[0049] In this embodiment, a fire extinguishing layer 130 is provided between the core surface 121 on the first side 101 and the core surface 121 on the second side 102 and the inner wall of the housing 110. Of course, in other embodiments, a fire extinguishing layer 130 may be provided separately between the core surface 121 on the first side 101 and the inner wall of the housing 110; or a fire extinguishing layer 130 may be provided separately between the core surface 121 on the second side 102 and the inner wall of the housing 110.

[0050] It is understandable that fire extinguishing layers 130 are provided between the core surface 121 of the first side 101 and the inner wall of the housing 110, which has a better heat absorption and cooling effect on the entire battery cell 100.

[0051] It's worth noting that the current design temperature range for the 100 battery cell is -10℃ to 60℃. However, in actual use, the 100 battery cell's electrical performance is most fully realized when the temperature is between 10℃ and 30℃. Therefore, related technologies typically use heating or liquid cooling to regulate the temperature of the 100 battery cell, keeping the temperature during charging and discharging within this range as close as possible to 10℃ to 30℃. This temperature is not activated during storage. In summer, under direct sunlight, the temperature of the 100 battery cell can reach over 40℃, and sometimes even 60℃. From a macroscopic perspective, this high temperature accelerates battery capacity decay, increases internal resistance, and raises the internal temperature of the 100 battery cell. From a microscopic perspective, this high temperature significantly increases the rate of internal chemical reactions, weakens the protective effect of the electrolyte membrane, reduces electrolyte stability, intensifies decomposition reactions, and accelerates thermal runaway.

[0052] Therefore, in this embodiment, the fire extinguishing layer 130 is provided with a fire extinguishing agent. When the battery cell 100 is in a high temperature state, the fire extinguishing agent automatically vaporizes and absorbs heat to cool the battery cell 100.

[0053] Among them, the condition of the battery cell 100 being in a high temperature state can be understood as the temperature of the battery cell 100 being above 40℃.

[0054] Understandably, when the battery cell 100 is at a high temperature, ambient heat is transferred to the fire extinguishing layer 130, causing the fire extinguishing agent to automatically vaporize. During vaporization, the fire extinguishing agent absorbs a large amount of latent heat, simultaneously lowering the surrounding temperature. This achieves heat absorption and cooling of the inside of the battery cell 100.

[0055] Optionally, the extinguishing agent includes perfluorohexanone. Perfluorohexanone is a colorless, odorless, and transparent liquid at room temperature with a boiling point of 48-49°C. It readily vaporizes and exists in a gaseous state, primarily relying on endothermic reaction to extinguish fires. The extinguishing concentration of perfluorohexanone is typically 4-6%, offering relatively high safety.

[0056] It is understandable that fire extinguishing layer 130 made of perfluorohexanone has the following advantages:

[0057] Firstly, when the battery cell 100 is in a high-temperature or open-flame state, the ambient heat is transferred to the fire extinguishing layer 130, and the perfluorohexanone in the fire extinguishing layer 130 can be released quickly and automatically. During the automatic vaporization process of the perfluorohexanone, it absorbs heat from the battery cell 100 to achieve the effect of cooling and extinguishing the fire.

[0058] Secondly, after the temperature of the battery cell 100 drops, the release of perfluorohexanone stops until the battery cell 100 is at a high temperature again, at which point it will automatically release again until the perfluorohexanone is completely consumed. Therefore, the fire extinguishing layer 130 made of perfluorohexanone can be used multiple times to absorb heat and cool the battery cell 100 multiple times.

[0059] Thirdly, during the automatic vaporization process, the perfluorohexanone-based fire extinguishing layer 130 is partially consumed, resulting in a thinner layer and a smaller space that can be released to buffer the expansion force between adjacent cells 100. This improves the buffer space between adjacent cells 100, reduces the expansion force between them, and allows the cells 100 to perform better, thus improving their overall performance.

[0060] In this embodiment, perfluorohexanone and a polymeric adhesive are used to form the fire extinguishing layer 130.

[0061] Of course, in other embodiments, the extinguishing agent can also be a substance such as heptafluoropropane or hexafluoropropane that absorbs heat and cools down through a vaporization reaction.

[0062] In this embodiment, the fire extinguishing layer 130 can be adhered to the core surface 121 of the core 120. Of course, in other embodiments, the fire extinguishing layer 130 can also be adhered to the inner wall of the housing 110.

[0063] Optionally, the fire extinguishing layer 130 can be fixed to the core surface 121 of the core 120 or the inner wall of the housing 110 by means of double-sided tape, hot melt adhesive, or other adhesives.

[0064] In one alternative embodiment, a fire extinguishing agent is coated on the large surface 121 of the core 120 to form a fire extinguishing layer 130. Alternatively, in other embodiments, the fire extinguishing agent can be coated on the inner wall of the housing 110 to form the fire extinguishing layer 130. The fire extinguishing agent can also be coated on both the large surface 121 of the core 120 and the inner wall of the housing 110 to form the fire extinguishing layer 130.

[0065] In this embodiment, the center of the fire extinguishing layer 130 is coaxially arranged with the center of the core surface 121, and the fire extinguishing layer 130 covers at least 1 / 3 of the area of ​​the core surface 121. It can be understood that the fire extinguishing layer 130 arranged in this way can cool the battery cell 100 to the maximum extent without affecting the internal installation of the battery cell 100.

[0066] In this embodiment, the shape of the fire extinguishing layer 130 includes at least one of the following: rectangular, circular, and arc-shaped. Please refer to... Figure 4 , Figure 4 A schematic diagram showing that the fire extinguishing layer 130 of a battery cell 100 is rectangular in shape; please refer to... Figure 5 , Figure 5 A schematic diagram showing that the fire extinguishing layer 130 of a battery cell 100 is circular in shape; please refer to... Figure 6 , Figure 6 A schematic diagram showing that the fire extinguishing layer 130 of a battery cell 100 is arc-shaped.

[0067] In this embodiment, the thickness of the fire extinguishing layer 130 is less than the distance between the large surface 121 of the core and the inner wall of the shell 110.

[0068] Optionally, the gap between the large surface 121 of the fire core and the inner wall of the shell 110 is normally designed to be 0.5 mm. Therefore, the thickness of the fire extinguishing layer 130 is less than 0.5 mm. The thickness of the fire extinguishing layer 130 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0069] It is understandable that the thickness of the fire extinguishing layer 130 is less than the normal design size of the gap between the core surface 121 and the inner wall of the shell 110, so as to avoid the excessively thick fire extinguishing layer 130 from squeezing the core 120 inside the battery cell 100, causing the core 120 to be squeezed and deformed.

[0070] The manufacturing process and technology of the battery cell 100 and battery provided in this utility model embodiment are as follows: 1. A fire extinguishing layer 130 is made by mixing perfluorohexanone and a polymer adhesive; 2. The fire extinguishing layer 130 is bonded to the core surface 121 of the core 120 and / or the inner wall of the shell 110; 3. The core 120 is welded to the top cover 140 and then inserted into the shell, and the top cover 140 is welded to the open end of the shell 110.

[0071] The working principle and process of the battery cell 100 and battery provided in this embodiment are as follows: When the battery cell 100 is in a high-temperature or open-flame state, the ambient heat is transferred to the fire extinguishing layer 130. The perfluorohexanone in the fire extinguishing layer 130 is rapidly and automatically released. During the automatic vaporization and heat absorption process of the perfluorohexanone, it absorbs heat from the battery cell 100 to achieve the effect of cooling and extinguishing the fire. At the same time, during the automatic vaporization process of the fire extinguishing layer 130, some of the perfluorohexanone is consumed, and the thickness of the fire extinguishing layer 130 becomes thinner, which can release a small amount of space to buffer the expansion force between adjacent battery cells 100.

[0072] Furthermore, after the temperature of cell 100 drops, perfluorohexanone stops being released until the cell 100 is at a high temperature again, at which point it will be released automatically again until the perfluorohexanone is completely consumed.

[0073] In summary, the battery cell 100 and battery provided in this embodiment of the present invention, through the fire extinguishing layer 130 disposed between the large surface 121 of the core and the inner wall of the housing 110, automatically absorb heat and cool the large surface 103 of the battery cell when the battery cell 100 is in a state of rapid temperature rise or high temperature, thereby reducing the temperature rise of the large surface 103 of the battery cell. This achieves individual cooling of a single battery cell 100, thereby reducing heat transfer between the large surfaces 103 of adjacent battery cells 100, avoiding temperature transfer and expansion between adjacent battery cells 100, and preventing the occurrence of battery thermal runaway in a timely manner. It can also improve the battery's electrical performance and prolong the battery's performance degradation.

[0074] Furthermore, by setting up a fire extinguishing layer 130 containing perfluorohexanone, the fire extinguishing layer 130 made of perfluorohexanone has the following advantages: First, when the battery cell 100 is in a high-temperature or open-flame state, ambient heat is transferred to the fire extinguishing layer 130, and the perfluorohexanone in the fire extinguishing layer 130 can be rapidly and automatically released. During the automatic vaporization process of the perfluorohexanone, it absorbs heat from the battery cell 100 to achieve the effect of cooling and extinguishing the fire. Second, after the temperature of the battery cell 100 drops, the release of perfluorohexanone stops until the next time the battery cell 100 is in a high-temperature state, at which point it will be automatically released again until the perfluorohexanone is completely consumed. Therefore, the fire extinguishing layer 130 made of perfluorohexanone can be used multiple times to absorb heat and cool the battery cell 100 multiple times. Thirdly, during the automatic vaporization process, the perfluorohexanone-based fire extinguishing layer 130 is partially consumed, resulting in a thinner layer and a smaller space that can be released to buffer the expansion force between adjacent cells 100. This improves the buffer space between adjacent cells 100, reduces the expansion force between them, and allows the cells 100 to perform better, thus improving their overall performance.

[0075] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations 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. An electric cell, characterized by, The battery cell has a large surface area on both the first and second opposing sides, and the battery cell includes: A housing and a core, the core being housed inside the housing, the core having two large core surfaces, the two large core surfaces being respectively disposed on a first side and a second side opposite to each other; A fire extinguishing layer is located between the large surface of the core and the inner wall of the housing. When the battery cell is in a high-temperature state, the fire extinguishing layer is used to automatically absorb heat and cool the battery cell.

2. The electric cell of claim 1, wherein, The fire extinguishing layer contains a fire extinguishing agent. When the battery cell is at a high temperature, the fire extinguishing agent automatically vaporizes and absorbs heat to cool the battery cell.

3. The electric cell of claim 2, wherein, The extinguishing agent includes perfluorohexanone, and the perfluorohexanone is combined with a polymer adhesive to form the extinguishing layer.

4. The cell of claim 2, wherein, The extinguishing agent is coated onto the large surface of the core and / or the inner wall of the housing to form the extinguishing layer.

5. The battery cell according to claim 1, characterized in that, The fire extinguishing layer is bonded to the large surface of the core or the inner wall of the shell.

6. The battery cell according to claim 1, characterized in that, The center of the fire extinguishing layer is coaxially arranged with the center of the large surface of the core, and the fire extinguishing layer covers at least 1 / 3 of the area of ​​the large surface of the core.

7. The battery cell according to claim 1, characterized in that, The thickness of the fire extinguishing layer is less than the distance between the large surface of the core and the inner wall of the shell. The thickness of the fire extinguishing layer is less than 0.5 mm.

8. The battery cell according to claim 1, characterized in that, The fire extinguishing layer is provided between the large surface of the core located on the first side and / or the large surface of the core located on the second side and the inner wall of the housing.

9. The battery cell according to claim 1, characterized in that, The shape of the fire extinguishing layer includes at least one of the following: rectangular, circular, and arc-shaped.

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

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