Battery cell and battery pack
By designing a combination of pressure relief holes and protrusions on the battery casing, the problems of increased casing thickness and core blockage were solved, enabling the smooth discharge of high-temperature gases and the maintenance of cell energy density.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SUNWODA MOBILITY ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-11-13
- Publication Date
- 2026-07-09
Smart Images
Figure CN2025134556_09072026_PF_FP_ABST
Abstract
Description
A battery cell and a battery pack
[0001] Cross-references to related applications
[0002] This application claims the benefit of Chinese Patent Application No. 202520015933.1, filed on January 2, 2025, the entire contents of which are incorporated herein by reference. Technical Field
[0003] This application relates to the field of battery technology, and in particular to a battery cell and a battery pack. Background Technology
[0004] Currently, batteries typically have a positive terminal, a negative terminal, and an explosion-proof valve designed into the top cover. However, in the event of cell abuse or extreme conditions, the battery is prone to double failure of electrical insulation and thermal runaway, making it difficult to guarantee the battery's safety performance.
[0005] To mitigate the risk of dual battery failure, a thermoelectric separation design is gradually being adopted. This design eliminates the top cover's explosion-proof valve, instead placing it at the bottom of the casing. This ensures that electrical connections and thermal runaway propagation do not interfere with each other in extreme situations. However, because the explosion-proof valve is welded to the bottom of the casing, the bottom layer needs sufficient thickness to withstand the welding requirements. Increasing the thickness of the bottom layer can lead to excessive casing weight, reducing the cell's energy density. Furthermore, with the explosion-proof valve located at the bottom, the battery core, due to its own weight, will press tightly against the bottom of the casing. The core may block the explosion-proof valve opening, preventing the proper escape of high-temperature gases during thermal runaway and potentially causing a battery explosion.
[0006] Therefore, the existing battery casings have an explosion-proof valve at the bottom, which requires increasing the bottom thickness and may result in excessive casing weight; moreover, the core may easily clog the explosion-proof valve port, making it impossible to ensure the smooth discharge of high-temperature gases caused by thermal runaway.
[0007] Application content
[0008] The technical problem this application aims to solve is that when the existing battery casing is designed with an explosion-proof valve at the bottom, the increased thickness can easily lead to excessive casing weight, and the core can easily clog the explosion-proof valve port, making it impossible to ensure the smooth discharge of high-temperature gases caused by thermal runaway.
[0009] To address the aforementioned technical problems, this application provides a technical solution for a single battery cell:
[0010] The battery cell has intersecting height, length, and width directions, including:
[0011] A housing having a receiving cavity inside, and an opening on one side of the housing along the height direction, the opening communicating with the receiving cavity;
[0012] A first cover plate, which seals the opening;
[0013] The housing has a second cover plate located on the side of the housing away from the opening along the height direction; the second cover plate has a pressure relief hole that penetrates the second cover plate along the height direction, and the second cover plate also has a protrusion around the pressure relief hole that protrudes toward the opening relative to the second cover plate;
[0014] An explosion-proof valve is installed enclosedly in the pressure relief port;
[0015] An insulating gasket is disposed within the accommodating cavity and located between the first cover plate and the second cover plate. The insulating gasket has an air guide groove and a clearance hole, both of which penetrate the insulating gasket along the height direction. The clearance hole and the pressure relief hole are arranged opposite each other along the height direction. The protrusion passes through the clearance hole and is clearance-fitted with the clearance hole. The air guide groove, the clearance hole, and the pressure relief hole are connected.
[0016] In one embodiment, along the height direction, the protrusion height of the protrusion relative to the second cover plate toward the opening is H1, the thickness of the insulating gasket is H2, and H1 ≤ H2.
[0017] In one embodiment, the protrusion includes a plurality of bosses, which are arranged around the pressure relief hole and spaced apart from each other.
[0018] Preferably, an air guide channel is formed between two adjacent protrusions, the air guide channel is located inside the clearance hole, and the air guide channel connects the pressure relief hole and the air guide groove.
[0019] More preferably, the air guide groove and the air guide channel are arranged to extend along the length direction.
[0020] In one embodiment, along the width direction, the width of the air guide channel is D1, the width of the air guide groove is D2, and D1≤D2.
[0021] In one embodiment, the pressure relief hole is located at the middle of the second cover plate in the length direction, and the clearance hole is located at the middle of the insulating gasket in the length direction; there are two air guide grooves, which are respectively located on opposite sides of the clearance hole along the length direction.
[0022] In one embodiment, the explosion-proof valve is integrally formed with the housing.
[0023] In one embodiment, the protrusion is integrally formed with the second cover plate.
[0024] In one embodiment, the second cover plate has a weak area surrounding the protrusion.
[0025] Furthermore, in the height direction, the thickness of the weak area is less than the thickness of the second cover plate.
[0026] In one implementation, the weak area is a notch.
[0027] In one embodiment, the battery cell further includes an electrode assembly, and the insulating pad is disposed between the electrode assembly and the second cover plate.
[0028] In one embodiment, a protective plate is also provided on the side of the explosion-proof valve away from the opening.
[0029] To address the aforementioned technical problems, this application provides a technical solution for a battery pack:
[0030] Battery pack, including individual battery cells;
[0031] The battery cell has intersecting height, length, and width directions, including:
[0032] A housing having a receiving cavity inside, and an opening on one side of the housing along the height direction, the opening communicating with the receiving cavity;
[0033] A first cover plate, which seals the opening;
[0034] The housing has a second cover plate located on the side of the housing away from the opening along the height direction; the second cover plate has a pressure relief hole that penetrates the second cover plate along the height direction, and the second cover plate also has a protrusion around the pressure relief hole that protrudes toward the opening relative to the second cover plate;
[0035] An explosion-proof valve is installed enclosedly in the pressure relief port;
[0036] An insulating gasket is disposed within the accommodating cavity and located between the first cover plate and the second cover plate. The insulating gasket has an air guide groove and a clearance hole, both of which penetrate the insulating gasket along the height direction. The clearance hole and the pressure relief hole are arranged opposite each other along the height direction. The protrusion passes through the clearance hole and is clearance-fitted with the clearance hole. The air guide groove, the clearance hole, and the pressure relief hole are connected.
[0037] In one embodiment, along the height direction, the protrusion height of the protrusion relative to the second cover plate toward the opening is H1, the thickness of the insulating gasket is H2, and H1 ≤ H2.
[0038] In one embodiment, the protrusion includes a plurality of bosses, which surround the pressure relief hole and are spaced apart from each other.
[0039] Preferably, an air guide channel is formed between two adjacent protrusions, the air guide channel is located within the clearance hole, and the air guide channel connects the pressure relief hole and the air guide groove.
[0040] More preferably, the air guide groove and the air guide channel are arranged to extend along the length direction.
[0041] In one embodiment, along the width direction, the width of the air guide channel is D1, the width of the air guide groove is D2, and D1≤D2.
[0042] In one embodiment, the pressure relief hole is located at the middle of the second cover plate in the length direction, and the clearance hole is located at the middle of the insulating gasket in the length direction; there are two air guide grooves, which are respectively located on opposite sides of the clearance hole along the length direction.
[0043] In one embodiment, the explosion-proof valve is integrally formed with the housing.
[0044] In one embodiment, the protrusion is integrally formed with the second cover plate.
[0045] In one embodiment, the second cover plate has a weak area surrounding the protrusion.
[0046] Furthermore, in the height direction, the thickness of the weak area is less than the thickness of the second cover plate.
[0047] In one implementation, the weak area is a notch.
[0048] In one embodiment, the battery cell further includes an electrode assembly, and the insulating pad is disposed between the electrode assembly and the second cover plate.
[0049] In one embodiment, a protective plate is also provided on the side of the explosion-proof valve away from the opening.
[0050] Compared with the prior art, the advantages of the battery cell and battery pack disclosed in this application are as follows: The battery cell adopts a design consisting of a housing, a first cover plate, a second cover plate, an explosion-proof valve, and an insulating gasket. The housing has a cavity and an opening for inserting electrode assemblies. The first cover plate is installed at the opening, sealing the cavity. The first cover plate has an electrical connection portion as an electrical terminal. The second cover plate is located on the side of the housing away from the opening along its height direction. The second cover plate has a pressure relief hole and a protrusion. The explosion-proof valve is installed at the pressure relief hole and seals it, opening to release high-temperature gas when the internal pressure of the housing is too high.
[0051] The protrusion protrudes from the surface of the second cover plate towards the opening. The second cover plate has a large local thickness only at the protrusion, avoiding excessive weight due to increased overall thickness and ensuring the energy density of the battery cell. Additionally, an insulating gasket is placed within the accommodating cavity between the first and second cover plates. This gasket provides support for the electrode assembly along its height, preventing potential blockage of the pressure relief hole. Furthermore, the insulating gasket has a venting groove and a clearance hole, which are positioned opposite the pressure relief hole along its height. The protrusion passes through the clearance hole and fits with it with a clearance. The venting groove, clearance hole, and pressure relief hole are interconnected, forming an effective gas channel to ensure the smooth discharge of high-temperature gases generated during thermal runaway. Attached Figure Description
[0052] Figure 1 is an exploded schematic diagram of a single battery cell in an embodiment of this application;
[0053] Figure 2 is a perspective view of the second cover plate and the insulating gasket in an embodiment of this application;
[0054] Figure 3 is a cross-sectional schematic diagram of a single battery cell along the width direction in an embodiment of this application;
[0055] Figure 4 is a partial enlarged view of the second cover plate and insulating gasket in Figure 3;
[0056] In the figure: 1-shell, 10-accommodating cavity, 2-first cover plate, 3-second cover plate, 30-pressure relief hole, 31-protrusion, 310-bore, 32-air guide channel, 33-weak area, 4-explosion-proof valve, 40-protective plate, 5-insulating gasket, 50-air guide groove, 51-avoidance hole, 6-electrode assembly, X-height direction, Y-length direction, Z-width direction. Detailed Implementation
[0057] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.
[0058] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" used to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the equipment or components 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 application.
[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0060] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0061] As shown in Figures 1 to 4, a battery cell according to an embodiment of this application has intersecting height direction X, length direction Y, and width direction Z, including a housing 1, a first cover plate 2, an explosion-proof valve 4, and an insulating gasket 5. The housing 1 has a receiving cavity 10, and the housing 1 has an opening 11 on one side along the height direction X, which communicates with the receiving cavity 10. The first cover plate 2 covers the opening 11. The housing 1 has a second cover plate 3, which is located on the side of the housing 1 along the height direction X away from the opening 11.
[0062] The second cover plate 3 has a pressure relief hole 30, which penetrates the second cover plate 3 along the height direction X. The second cover plate 3 also has a protrusion 31 around the pressure relief hole 30, which protrudes towards the opening 11 relative to the second cover plate 3. The explosion-proof valve 4 is installed in the pressure relief hole 30. The insulating gasket 5 is placed in the accommodating cavity 10 and located between the first cover plate 2 and the second cover plate 3. The insulating gasket 5 has a venting groove 50 and a clearance hole 51, which both penetrate the insulating gasket 5 along the height direction X. The clearance hole 51 is opposite to the pressure relief hole 30 along the height direction X. The protrusion 31 passes through the clearance hole 51 and is clearance-fitted with the clearance hole 51. The venting groove 50, the clearance hole 51 and the pressure relief hole 30 are connected.
[0063] The battery cell adopts a design consisting of a housing 1, a first cover plate 2, a second cover plate 3, an explosion-proof valve 4, and an insulating gasket 5. The housing 1 has a receiving cavity 10 and an opening 11, allowing the electrode assembly 6 to be installed inside the housing 1. The first cover plate 2 is installed at the opening 11, forming a seal around the receiving cavity 10. The first cover plate 2 is provided with an electrical connection portion as an electrical terminal. The second cover plate 3 is located on the side of the housing 1 away from the opening 11 along the height direction X. The second cover plate 3 is provided with a pressure relief hole 30 and a protrusion 31. The explosion-proof valve 4 is installed in the pressure relief hole 30 and seals the pressure relief hole 30, and opens to release high-temperature gas when the internal pressure of the housing 1 is too high.
[0064] The protrusion 31 protrudes from the surface of the second cover plate 3 toward the opening 11. The second cover plate 3 has a large local thickness only in the protrusion 31, which avoids increasing the overall thickness of the second cover plate 31 and causing the weight of the housing 1 to be too large, thus ensuring the energy density of the battery cell. In addition, the insulating gasket 5 is disposed in the accommodating cavity 10 and located between the first cover plate 2 and the second cover plate 3, specifically between the electrode assembly 6 and the second cover plate 3. The insulating gasket 5 provides support for the electrode assembly 6 in the height direction X, preventing the electrode assembly 6 from blocking the pressure relief hole 30. Moreover, the insulating gasket 5 has a venting groove 50 and a clearance hole 51. The clearance hole 51 is arranged opposite to the pressure relief hole 30 in the height direction X. The protrusion 31 passes through the clearance hole 51 and is clearance-fitted with the clearance hole 51. The venting groove 50, the clearance hole 51 and the pressure relief hole 30 are connected, forming an effective gas channel from the venting groove 50, the clearance hole 51 to the pressure relief hole 30, ensuring that the high-temperature gas generated during thermal runaway can be discharged smoothly.
[0065] In this embodiment, along the height direction X, the protrusion height of the protrusion 31 relative to the surface of the second cover plate 3 facing the opening 11 is H1, and the thickness of the insulating gasket 5 is H2, where H1 ≤ H2. Specifically, 0.2mm ≤ H1 ≤ 2.2mm, and 0.25mm ≤ H2 ≤ 3mm. For example, H1 can be 0.2mm, 0.3mm, 0.5mm, 1mm, 2mm, or any other size between 0.2mm and 2.2mm; correspondingly, H2 can be 0.25mm, 0.4mm, 0.7mm, 1.5mm, 3mm, or any other size between 0.25mm and 3mm, and not less than H1. The greater thickness of the insulating gasket 5 provides stable support for the electrode assembly 6 in the height direction X, and maximizes the gap between the electrode assembly 6 and the protrusion 31 to ensure the smooth flow of high-temperature gas into the pressure relief hole 30. In addition, a protective plate 40 is installed on the pressure relief hole 30. The protective plate 40 is located on the side of the explosion-proof valve 4 away from the opening 11. The protective plate 40 can protect the explosion-proof valve 4 to prevent damage caused by external forces.
[0066] As a further preferred embodiment, the protrusion 31 includes multiple bosses 310, which surround the pressure relief hole 30 and are arranged at intervals. The protrusion 31 adopts a split design with multiple bosses 310, which can ensure stable support of the explosion-proof valve 4 and reduce the area of the area where the protrusion 31 is located. Moreover, an air guide channel 32 is formed between two adjacent bosses 310, which connects the pressure relief hole 30 and the air guide groove 50, ensuring a smoother exhaust path from the air guide groove 50 to the pressure relief hole 30.
[0067] Within the housing 1, the air guide groove 50 and the air guide channel 32 extend along the length direction Y, effectively connecting the electrode assembly 6 and the pressure relief hole 30. Furthermore, along the width direction Z, the width of the air guide channel 32 is D1, and the width of the air guide groove 50 is D2, with D1 ≤ D2, thus avoiding the formation of an exhaust bottleneck at the protrusion 31. Specifically, D1 can be any size between 2mm and 60mm; correspondingly, D2 can be any size between 2mm and 70mm, with D2 ≥ D1.
[0068] In this embodiment, the pressure relief hole 30 is located in the middle of the second cover plate 3 in the length direction Y, and the clearance hole 51 is located in the middle of the insulating gasket 5 in the length direction Y. There are two air guide grooves 50, which are respectively located on opposite sides of the clearance hole 51 along the length direction Y. In the housing 1, an exhaust path converging from both sides to the middle is formed along the length direction Y, which ensures the smoothness of the exhaust path.
[0069] Furthermore, the explosion-proof valve 4 is integrally formed with the housing 1, and the protrusion 31 is integrally formed with the second cover plate 3. The protrusion 31 and the second cover plate 3 are integrally stamped, which simplifies the assembly method of the protrusion 31 and the second cover plate 3. Moreover, the second cover plate 3 is provided with a weak area 33, which surrounds the protrusion 31. Specifically, the weak area 33 is a groove, and the thickness of the weak area 33 is less than the thickness of the second cover plate 3. The area surrounded by the weak area 33 is larger. When thermal failure occurs, the weak area 33 can form a larger vent hole, which improves the venting effect and provides supplementary pressure relief for the explosion-proof valve 4.
[0070] One embodiment of this application provides a battery pack, which includes individual battery cells. The specific embodiments of the individual battery cells in the specific implementations of this application are the same, and will not be repeated here.
[0071] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.
Claims
1. A battery cell having intersecting height (X), length (Y), and width (Z) directions, wherein, The battery cell includes: A housing (1) having a cavity (10) inside, and an opening (11) on one side along the height direction (X) of the housing (1) communicating with the cavity (10); A first cover plate (2) is used to seal the opening (11); The housing (1) has a second cover plate (3), which is located on the side of the housing (1) away from the opening (11) along the height direction (X); the second cover plate (3) has a pressure relief hole (30), which penetrates the second cover plate (3) along the height direction (X), and the second cover plate (3) also has a protrusion (31) around the pressure relief hole (30), which protrudes toward the opening (11) relative to the second cover plate (3); An explosion-proof valve (4) is installed in a closed manner in the pressure relief hole (30); An insulating gasket (5) is disposed in the accommodating cavity (10) and located between the first cover plate (2) and the second cover plate (3). The insulating gasket (5) has an air guide groove (50) and a clearance hole (51). The air guide groove (50) and the clearance hole (51) both penetrate the insulating gasket (5) along the height direction (X). The clearance hole (51) and the pressure relief hole (30) are arranged opposite to each other along the height direction (X). The protrusion (31) passes through the clearance hole (51) and is clearance-fitted with the clearance hole (51). The air guide groove (50), the clearance hole (51) and the pressure relief hole (30) are connected.
2. The battery cell according to claim 1, wherein, Along the height direction (X), the protrusion height of the protrusion (31) relative to the second cover plate (3) toward the opening (11) is H1, the thickness of the insulating pad (5) is H2, and H1≤H2.
3. The battery cell according to claim 1, wherein, The protrusion (31) includes a plurality of bosses (310), which surround the pressure relief hole (30) and are arranged at intervals to each other.
4. The battery cell according to claim 3, wherein, An air guide channel (32) is formed between two adjacent bosses (310). The air guide channel (32) is located inside the clearance hole (51) and the air guide channel (32) connects the pressure relief hole (30) and the air guide groove (50).
5. The battery cell according to claim 4, wherein, The air guide groove (50) and the air guide channel (32) are arranged to extend along the length direction (Y).
6. The battery cell according to claim 4, wherein, Along the width direction (Z), the width of the air guide channel (32) is D1, the width of the air guide groove (50) is D2, and D1≤D2.
7. The battery cell according to claim 1, wherein, The pressure relief hole (30) is located in the middle of the second cover plate (3) in the length direction (Y), and the clearance hole (51) is located in the middle of the insulating gasket (5) in the length direction (Y). The air guide grooves (50) are two in number and are respectively located on opposite sides of the clearance hole (51) along the length direction (Y).
8. The battery cell according to claim 1, wherein, The explosion-proof valve (4) is integrally formed with the housing (1).
9. The battery cell according to claim 1, wherein, The protrusion (31) is integrally formed with the second cover plate (3).
10. The battery cell according to claim 9, wherein, The second cover plate (3) is provided with a weak area (33), which is arranged around the protrusion (31).
11. The battery cell according to claim 10, wherein, In the height direction (X), the thickness of the weak area (33) is less than the thickness of the second cover plate (3).
12. The battery cell according to claim 11, wherein, The weak area (33) is a scratch.
13. The battery cell according to claim 1, wherein, The battery cell also includes an electrode assembly (6), and the insulating pad (5) is disposed between the electrode assembly (6) and the second cover plate (3).
14. The battery cell according to claim 1, wherein, A protective plate (40) is also provided on the side of the explosion-proof valve (4) away from the opening (11).
15. A battery pack, wherein, Includes the battery cell as described in any one of claims 1 to 13.