An explosion-proof valve, an electric core shell and a battery

Abstract

The utility model relates to battery technology field and provide a kind of explosion-proof valve, battery cell shell and battery, the explosion-proof valve includes plate main body and annular boss being set on the plate main body, the plate main body includes the ring outer plate being located the annular boss outside and being arranged around the annular boss and the ring inner plate being located the annular boss inside, the outer circumferential wall of the annular boss is used to be welded with the hole wall of the mounting hole of battery cell shell, the ring outer plate is used to abut with the inner wall of the battery cell shell, the ring inner plate is equipped with notch. Prevent the undesirable phenomenon of welding process from appearing welding leak, ensure the safety in the process of battery manufacturing, also because the two-layer board structure and the setting of annular boss, the thickness of battery cell shell can be correspondingly moderately reduced, the weight of battery cell shell is reduced, the effective space in battery cell is increased, and the volume energy density of battery is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to an explosion-proof valve, a cell housing, and a battery. Background Technology

[0002] In the battery manufacturing industry, especially for lithium-ion batteries, to improve battery safety, the industry generally designs explosion-proof valves on the cell casing. In the event of a short circuit, overcharge, or overheating, the explosion-proof valve senses changes in internal pressure and opens promptly to release gas and pressure, preventing risks such as cell explosion or fire. Currently, during the installation of the explosion-proof valve on the cell casing, it is generally fixed to a pre-drilled hole in the cell casing by welding. To prevent the cell casing from being welded through during the welding process, leading to gas leakage, the wall thickness of the side of the cell casing where the explosion-proof valve is located must be greater than the weld penetration depth, typically greater than 1 mm.

[0003] However, as the new energy battery industry continues to demand lighter and higher volumetric energy density products, technical solutions with cell casing thicknesses greater than 1 mm are gradually revealing some technical drawbacks. On the one hand, thicker cell casings occupy more effective space inside the cell, directly compressing the volume of active materials and significantly restricting the improvement of volumetric energy density. On the other hand, thicker cell casings also increase the overall weight of the battery, contradicting the current trend of lightweight development in power batteries and portable device batteries. However, if the cell casing thickness is reduced to meet the core requirements of weight reduction and increased volumetric energy density, the wall thickness will be less than the weld penetration depth during the welding of explosion-proof valves, making it easy to be welded through during the welding process, leading to problems such as cell sealing failure and gas leakage. Utility Model Content

[0004] The technical problem to be solved by this invention is: how to improve the volumetric energy density of a battery while ensuring battery safety.

[0005] This utility model provides an explosion-proof valve, including a plate-shaped body and an annular boss disposed on the plate-shaped body. The plate-shaped body includes an outer annular plate located outside the annular boss and surrounding the annular boss, and an inner annular plate located inside the annular boss. The outer peripheral wall of the annular boss is used for welding to the wall of the mounting hole of the battery cell housing. The outer annular plate is used for abutting against the inner wall of the battery cell housing. The inner annular plate is provided with grooves.

[0006] Optionally, a weld is formed at the connection between the outer peripheral wall of the annular boss and the wall of the mounting hole, and the projection of the weld on the plate-shaped body is entirely located within the plate-shaped body.

[0007] Optionally, the outer contour of the outer ring plate and the outer contour of the annular boss are both adapted to match the shape of the mounting hole, the mounting hole is a waist-shaped hole, and the projections of the starting end and the ending end of the weld on the plate-shaped body are both located within the same arc segment of the outer ring plate.

[0008] Optionally, the width of the arc segment of the outer ring plate is greater than the width of the straight segment of the outer ring plate.

[0009] Optionally, the groove is formed along the outer edge of the inner ring plate, and the beginning and end of the groove are spaced apart.

[0010] Optionally, the top surface of the annular boss is configured such that, after welding, the inner ring profile of the weld is located within the range of the top surface of the annular boss.

[0011] Compared with related technologies, the explosion-proof valve provided by this utility model has the following technical advantages: The explosion-proof valve provided by this utility model can be applied to, for example, the casing of a lithium-ion battery cell. By setting a plate-shaped main body, it is easy to weld it to the cell casing to form an integral planar structure, without occupying internal space of the cell casing. Furthermore, by setting the plate-shaped main body into a structure with an outer ring plate, an annular boss, and an inner ring plate arranged in sequence, with the inner ring plate located within the mounting hole and grooved, when problems such as short circuits, overcharging, or overheating occur inside the cell, the internal air pressure increases, and the inner ring plate can break through the groove, thus opening the explosion-proof valve to release air and pressure, ensuring the safety of battery use. Additionally, by welding the annular boss to the wall of the mounting hole in the cell casing, the annular line of the abutment serves as the welding path. The annular boss effectively thickens the explosion-proof valve at this point, providing a more stable and secure weld. The outer ring plate provides support and prevents the weld from penetrating during the welding process. Furthermore, by abutting the inner wall of the cell casing with the outer ring plate continuously connected to the annular boss, the area around the mounting hole—that is, the welding path around the mounting hole—is a two-layer structure consisting of the cell casing and the outer ring plate. Even if the cell casing is thin and welds through it, the outer ring plate underneath continues to serve as a welding medium and support, further preventing weld penetration and leakage during welding, ensuring safety in the battery manufacturing process. Simultaneously, due to this two-layer structure and the annular boss, the thickness of the cell casing can be appropriately reduced, decreasing its weight and increasing the effective space within the cell, thus improving the battery's volumetric energy density.

[0012] In addition, this utility model also provides a battery cell housing, including a housing, a cover plate and the aforementioned explosion-proof valve, wherein the housing has an installation hole and the explosion-proof valve is welded to the installation hole.

[0013] Optionally, the thickness of the shell is 0.2 mm ≤ h < 0.6 mm.

[0014] Optionally, the housing is cuboid, with one narrow wall of the housing protruding outward and forming a receiving groove on the inner side. The mounting hole is opened in the bottom wall of the receiving groove, and the outer ring plate of the explosion-proof valve is located in the receiving groove and abuts against the bottom wall of the receiving groove.

[0015] Compared with related technologies, the battery cell housing provided by this utility model has roughly the same technical effect as the explosion-proof valve mentioned above by setting the explosion-proof valve, which will not be repeated here. At the same time, by setting the housing and the cover plate, a closed and sealed internal space of the battery cell can be formed. Moreover, by welding the explosion-proof valve to the mounting hole of the housing, that is, the explosion-proof valve and the cover plate are on different sides, the housing can be designed to be thinner, reducing weight and increasing the internal space of the battery cell, thereby improving the volumetric energy density.

[0016] In addition, this utility model also provides a battery, including the explosion-proof valve and / or the cell casing mentioned above.

[0017] Compared with related technologies, the battery provided by this utility model, by setting the above-mentioned explosion-proof valve and / or the above-mentioned cell shell, has roughly the same technical effect as the above-mentioned explosion-proof valve and / or the above-mentioned cell shell, and will not be described in detail here. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the explosion-proof valve according to an embodiment of the present utility model; Figure 2 This is a schematic diagram of the planar structure of the explosion-proof valve according to an embodiment of the present invention; Figure 3 This is a cross-sectional view of the explosion-proof valve according to an embodiment of the present invention; Figure 4 This is a three-dimensional structural diagram of the battery cell housing according to an embodiment of the present invention; Figure 5 This is an exploded structural diagram of the battery cell housing according to an embodiment of the present invention; Figure 6 This is a partial cross-sectional view of the battery cell housing according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the planar structure of the weld seam in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 11-Outer ring plate, 111-Arc segment, 112-Straight segment, 12-Annular boss, 13-Inner ring plate, 14-Score, 21-Mounting hole, 22-Shell, 221-Bottom wall of receiving groove, 30-Weld, 31-Starting end, 32-Ending end, L1-Explosion-proof valve length, L2-Weld mark length, W1-Explosion-proof valve width, W2-Weld mark width, D1-Weld mark width, D2-Arc segment width, D3-Straight segment width, D4-Top width of annular boss. Detailed Implementation

[0020] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0021] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this utility model described herein can be implemented in sequences other than those illustrated or described herein.

[0022] In the description of this utility model, the orientation or positional relationship indicated by terms such as "up", "down", "left", "right", "top", "bottom", "front", "back", "inner" and "outer" is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing this utility model and is not intended to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the scope of protection 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 "set," "install," "connect," and "link" 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; 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] In the description of this specification, references to terms such as "embodiment," "one embodiment," and "one implementation" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or illustrative embodiment of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0025] like Figures 1 to 6 As shown, this utility model embodiment provides an explosion-proof valve, including a plate-shaped body and an annular boss 12 disposed on the plate-shaped body. The plate-shaped body includes an outer annular plate 11 located outside the annular boss 12 and an inner annular plate 13 located inside the annular boss 12. The annular boss 12 is used to weld to the wall of the mounting hole 21 of the battery cell shell after abutting. The outer annular plate 11 is used to abut against the inner wall of the battery cell shell. The inner annular plate 13 is provided with a groove 14.

[0026] In related technologies, battery manufacturing commonly uses welding to fix the explosion-proof valve into a pre-drilled hole in the cell casing. To prevent the weld penetration through the casing, the cell casing wall thickness typically needs to be greater than 1 mm. This design results in the casing occupying too much internal space, limiting the volume of battery active materials and hindering the improvement of volumetric energy density. Simultaneously, the excessively thick casing material increases the overall weight, contradicting the lightweight requirements of power batteries and portable device batteries. Attempting to thin the casing wall thickness can easily lead to weld penetration during the welding process, causing cell sealing failure and the risk of gas leakage. This creates a technical contradiction: increasing battery volumetric energy density by reducing casing thickness leads to unsafe battery conditions.

[0027] In this embodiment of the utility model, the battery cell housing includes a shell 22, which has a mounting hole 21. The explosion-proof valve is an integrally formed plate structure, including a plate-shaped main body and an annular boss 12. The annular boss 12 is a protrusion on one side surface of the plate-shaped main body, and the protrusion extends on the surface of the plate-shaped main body to form an annular closed loop. The outer plate 11 refers to the part of the plate-shaped main body located outside the annular boss 12 and surrounding the annular boss 12, and its outer diameter is larger than the diameter of the mounting hole 21. The outer plate 11 forms a pre-contact with the inner wall of the shell 22 before welding. The annular boss 12 is located inside the mounting hole 21, and its outer peripheral wall abuts against the hole wall of the mounting hole 21 to form a limit. The inner plate 13 refers to the plate-shaped main body located inside the annular boss 12. That is, the inner plate 13 and the outer plate 11 are located on the inner and outer sides of the annular boss 12, respectively. The outer plate 11, the annular boss 12, and the inner plate are integrally formed. The outer peripheral wall of the annular boss 12 forms surface contact with the wall of the mounting hole 21, and the two are welded together to form a weld 30. The weld 30 is an annular line formed at the contact point between the annular boss 12 and the wall of the mounting hole 21. The inner ring plate 13 is a plate located in the central area of ​​the explosion-proof valve, which is in the area of ​​the mounting hole 21. The groove 14 can be opened on the edge of the inner ring plate 13 as a preset explosion-proof pressure relief breaking path. This structure forms a preferred breaking path while maintaining the overall strength of the inner ring plate 13.

[0028] Specifically, during the welding process between the explosion-proof valve and the battery cell housing, laser welding can be used to abut the inner wall of the housing 22 around the mounting hole 21 to form an axial limit, and the outer peripheral wall of the annular boss 12 abuts the hole wall of the mounting hole 21 to form a radial limit. At the same time, the heat generated by welding will fuse the annular boss 12 and the hole wall of the mounting hole 21 to achieve the connection between the two. It should be noted that both the housing 22 and the explosion-proof valve can be made of aluminum, which is lightweight and durable. In related technologies, the weld penetration depth during the welding process, i.e., the heat energy, may melt through the thinner shell 22. In this embodiment, since there is a plate-shaped main body on the side of the annular boss 12 facing the inner side of the shell, the plate-shaped main body strengthens the thickness of the annular boss 12 used for welding with the shell 22, and the outer ring plate 11 compensates for the insufficient wall thickness of the shell 22 around the mounting hole 21, thereby preventing and reducing the risk of the surrounding wall of the shell 22 being welded through during welding. As a result, the cell shell can be made relatively thin, for example, with a thickness of 0.2 mm to 0.6 mm. Compared with the shells with a thickness of more than 1 mm in related technologies, it has a significant reduction in thickness. Thus, by reducing the shell thickness, weight reduction and volumetric energy density can be achieved, while ensuring the safety of the battery.

[0029] In this embodiment, the explosion-proof valve provided can be applied to, for example, the casing of a lithium-ion battery cell. By setting a plate-shaped main body, it is easy to weld it to the cell casing to form an integral planar structure, without occupying internal space of the cell casing. Furthermore, by setting the plate-shaped main body into a structure with an outer ring plate 11, an annular boss 12, and an inner ring plate 13 arranged sequentially, with the inner ring plate 13 located within the mounting hole 21 and having a notch 14, when problems such as short circuits, overcharging, or overheating occur inside the cell, the internal air pressure increases, and the inner ring plate 13 can break through the notch 14, thus opening the explosion-proof valve to release air and pressure, ensuring the safety of battery use. Additionally, by welding the annular boss 12 to the wall of the mounting hole 21 of the cell casing, with the abutting annular line serving as the welding path, the annular boss 12 effectively thickens the explosion-proof valve at this point, providing greater stability. The welding supports are firmly secured, preventing burn-through during the welding process. Furthermore, by abutting the outer ring plate 11 against the inner wall of the cell casing, and with the outer ring plate 11 and the annular boss 12 continuously arranged, meaning the inner wall of the cell casing around the mounting hole 21 is abutted against the outer ring plate 11, the area around the mounting hole 21, i.e., the welding path around the mounting hole 21, is a two-layer structure consisting of the cell casing and the outer ring plate 11 superimposed. Even if the cell casing is thin and burns through, the outer ring plate 11 continues to serve as a welding medium and support, further preventing burn-through and gas leakage during welding, ensuring safety during battery manufacturing. Simultaneously, due to this two-layer structure and the annular boss 12, the thickness of the cell casing can be appropriately reduced, the weight of the cell casing can be lightened, the effective space inside the cell can be increased, and the volumetric energy density of the battery can be improved.

[0030] Optionally, such as Figures 1 to 4 and Figure 7 As shown, a weld 30 is formed at the connection between the outer peripheral wall of the annular boss 12 and the hole wall of the mounting hole 21. The projection of the weld 30 on the plate-shaped body is entirely located within the plate-shaped body.

[0031] Specifically, the outer peripheral wall of the annular boss 12 and the wall of the mounting hole 21 are welded together by laser welding, forming a weld 30. The overall shape of the weld 30 matches the shape of the mounting hole 21, and the projection of the weld 30 onto the plate-shaped body is entirely within the plate-shaped body. Figure 7 As shown, weld 30 covers the dimensions of the plate-shaped body along the length of the explosion-proof valve, meaning the weld length L2 is less than the length L1 of the explosion-proof valve. Weld 30 also covers the dimensions of the plate-shaped body along the width of the explosion-proof valve, meaning the weld width W2 is less than the width W1 of the explosion-proof valve. This ensures that the projection of weld 30 on the plate-shaped body falls entirely within the dimensions of the explosion-proof valve, i.e., within the dimensions of the plate-shaped body. In other words, it ensures that the welding path and weld fusion area are entirely within the support and protection range of the explosion-proof valve during the welding process.

[0032] In this embodiment, by forming a weld 30 at the connection between the outer peripheral wall of the annular boss 12 and the hole wall of the mounting hole 21, the continuous welding and fixing of the cell shell and the explosion-proof valve is ensured, thus guaranteeing the structural robustness and the sealing performance of the cell. Furthermore, by ensuring that the projection of the weld 30 on the plate-shaped body is entirely within the plate-shaped body, the welding area can be strictly confined within the structure of the explosion-proof valve, preventing the weld 30 from extending beyond the explosion-proof valve into the thin shell and preventing the welding energy from diffusing into the shell and causing burn-through. At the same time, the integrity of the welding sealing surface can be guaranteed, avoiding local sealing failure due to the offset of the weld 30, thus ensuring the safety of battery manufacturing and use. Additionally, the cell shell can be appropriately thinned based on this structure to improve its volumetric energy density.

[0033] Optionally, such as Figures 1 to 4 and Figure 7 As shown, the outer contour of the outer ring plate 11 and the outer contour of the annular boss 12 are both adapted to fit the shape of the mounting hole 21. The mounting hole 21 is a waist-shaped hole. The projections of the starting end 31 and the ending end 32 of the weld 30 on the plate-shaped body are both located within the same arc segment 111 of the outer ring plate 11.

[0034] Specifically, the mounting hole 21 is an oblong hole. The outer contour of the outer ring plate 11 and the outer contour of the annular boss 12 are both adapted to the shape of the mounting hole 21. Therefore, the inner and outer edges of the outer ring plate 11 are both oblong hole shapes, and the annular boss 12 is also an annular protrusion structure in the shape of an oblong hole. The oblong outer ring plate 11 is composed of two opposing straight segments 112 and two opposing arc segments 111. The weld 30 is formed after welding, for example, by laser welding. It should be noted that during continuous laser welding of an explosion-proof valve, the welding power at the beginning and end of the welding is not stable enough. Therefore, to ensure the stability and firmness of the overall welded structure, it is necessary to perform residual welding at the starting end 31 and the ending end 32 outside the preset welding path, such as... Figure 7 As shown, the starting end 31 and the ending end 32 of the weld 30 both protrude from the circumferential welding path, thereby improving the connection stability and structural strength of the welded structure.

[0035] In this embodiment, by setting the outer contour of the outer ring plate 11 and the outer contour of the annular boss 12 to an oblong shape that matches the shape of the mounting hole 21, it facilitates precise manufacturing and adapts to the battery cell housing. For example, since explosion-proof valves are typically installed on the narrow wall of the housing 22 of the battery cell housing, the oblong shape not only fits the narrow wall but also makes full use of its narrow wall area, providing a relatively large explosion-proof space. Furthermore, by setting the projections of the starting end 31 and the ending end 32 of the weld 30 onto the plate-shaped body to the same point on the outer ring plate 11, the overall design is optimized. Within the arc-shaped segment 111, which is located at one end along the length of the outer ring plate 11, sufficient margin is ensured for the starting end 31 and the ending end 32 of the weld 30. In other words, the arc-shaped segment 111 at the end along the length of the outer ring plate 11 has a relatively sufficient area to compensate for the starting end 31 and the ending end 32 of the weld 30 from welding through the battery cell casing 22, further ensuring the safety of the battery cell. At the same time, the starting end 31 and the ending end 32 of the weld 30 are located at the same end of the outer ring plate 11, which also ensures the continuity and stability of the welding and is more in line with the setting of the welding path, making it easier to process and manufacture.

[0036] Optionally, such as Figures 2 to 6 As shown, the width of the arc segment 111 of the outer ring plate 11 is greater than the width of the straight segment 112 of the outer ring plate 11.

[0037] Specifically, the outer ring plate 11 is an annular plate adapted to the shape of the waist-shaped hole, that is, it has two arc-shaped segments 111 at its two opposite ends in the length direction and two straight segments 112 at its two opposite ends in the width direction, wherein the width of the arc-shaped segments 111 is greater than the width of the straight segments 112, that is, as shown in the figure. Figure 2As shown, the width D2 of the arc segment is greater than the width D3 of the straight segment. More specifically, the width of the arc segment 111 of the outer ring plate 11 refers to the shortest distance from the outer edge of the arc segment 111 to the outer edge of the annular boss 12, and the width of the straight segment 112 refers to the shortest distance from the outer edge of the straight segment 112 to the outer edge of the annular boss 12. This arrangement is more suitable for the battery cell housing and makes the structure more stable and robust.

[0038] In this embodiment, by setting the width of the arc segment 111 of the outer ring plate 11 to be greater than the width of the straight segment 112 of the outer ring plate 11, on the one hand, it is more suitable for the narrow wall installation of the battery cell housing 22 and saves the material of the explosion-proof valve. While adapting to the narrow wall of the housing 22, it saves as much material as possible for the straight segment 112. On the other hand, the starting end 31 and the ending end 32 of the weld 30 are both located within the arc segment 111. The wider arc segment 111 can provide a larger welding space, avoiding the starting end 31 and the ending end 32 of the weld 30 from exceeding the area of ​​the arc segment 111 due to insufficient width of the arc segment 111, thereby further preventing the occurrence of weld burn-through and further improving safety. At the same time, it can enhance the structural strength of the arc segment 111 area, making the overall structure more stable and solid.

[0039] Optionally, such as Figures 1 to 3 As shown, the notch 14 is opened along the outer edge of the inner ring plate 13, and the two ends of the notch 14 are spaced apart.

[0040] Specifically, the notch 14 is located on the upper surface of the inner ring plate 13, that is, the outward surface of the inner ring plate 13, which facilitates processing and makes it more controllable. The notch 14 serves as the path for the cell to break first when the internal pressure is too high. Its specific width and depth can be set according to the specific parameters of the actual cell, and are not specifically limited here.

[0041] In this embodiment, by creating the notch 14 along the outer edge of the inner ring plate 13, the notch 14 serves as a preset path for the first break when the internal pressure of the battery cell becomes too high. This creates an opening with the largest possible area, effectively lifting the entire inner ring plate 13 upon explosion. This allows for timely and effective pressure relief, ensuring overall safety. Furthermore, by setting the beginning and end of the notch 14 at intervals (i.e., not connected), the notch 14 is an open annular structure, preventing it from forming a closed loop. This non-complete annular structure ensures that even when pressure is released from the notch 14, the inner ring plate 13 remains partially connected to the explosion-proof valve body. This prevents the entire inner ring plate 13 from flying out during explosion pressure relief, thus avoiding secondary damage and further enhancing overall safety.

[0042] Optionally, such as Figures 2 to 7 As shown, the top surface of the annular boss 12 is configured such that, after welding, the inner ring profile of the weld 30 is located within the range of the top surface of the annular boss 12.

[0043] Specifically, such as Figure 7 As shown, the weld 30 formed by, for example, laser welding has a weld mark width D1 of approximately 0.6 mm. The weld 30 is formed by welding and fusing the top of the annular boss 12 with the housing 22 surrounding the top of the mounting hole 21. The welding path is a loop where the annular boss 12 and the mounting hole 21 abut. Thus, half of the weld mark width is located at the top of the annular boss 12, and the other half is located within the outer ring plate 11. The width D4 at the top of the annular boss is greater than 0.3 mm, which is greater than half the weld mark width D1, ensuring that the weld 30 does not exceed the annular boss 12. Simultaneously, the widths D2 (arc section) and D3 (straight section) of the outer ring plate 11 are also greater than 0.3 mm, similarly ensuring that the weld 30 does not exceed the area of ​​the outer ring plate 11, further guaranteeing that the weld will not burn through. It should be noted that, in order to accommodate the narrow walls of the battery cell housing 22, the maximum range of straight segment width D3 and annular boss top width D4 is generally no more than 1.5 mm. Of course, the specific structural dimensions need to be designed according to the actual specific parameters.

[0044] In this embodiment, the top surface of the annular boss 12 is configured such that, after welding, the inner ring contour of the weld 30 is located within the range of the top surface of the annular boss 12. That is, the top width of the annular boss 12 is set to be greater than half the width of the weld 30, i.e., the top width D4 of the annular boss is greater than half the width D1 of the weld mark. When welding, the weld 30 is formed by welding and fusing the top of the annular boss 12 with the housing 22 around the top of the mounting hole 21. The welding path is the loop line where the annular boss 12 and the mounting hole 21 abut. Thus, half the width of the weld mark 30 is located within the top surface of the annular boss 12. With the above configuration, the weld 30 located at the top of the annular boss 12 can be effectively prevented from exceeding the area of ​​the annular boss 12, ensuring the firmness and stability of the welded structure. At the same time, the thicker annular boss 12 can effectively prevent the heat generated during welding from melting through the explosion-proof valve, ensuring the overall sealing and safety.

[0045] In addition, such as Figures 4 to 6 As shown, another embodiment of the present invention provides a battery cell housing, including a housing 22, a cover plate and the aforementioned explosion-proof valve. The housing 22 has a mounting hole 21, and the explosion-proof valve is welded to the mounting hole 21.

[0046] Specifically, the housing 22 is a cuboid structure with open ends or one open end. The cover plate can be sealed to the open ends or one open end of the housing 22 to form a sealed cavity for the battery cell. The explosion-proof valve can be laser-welded to the mounting hole 21, and the mounting hole 21 is located on a narrow wall of the housing 22, which reduces the space occupied by the explosion-proof valve and makes it easier to perform explosion-proof pressure relief, as well as facilitate the design of the overall explosion-proof pressure relief and thermal runaway prevention path of the battery. Furthermore, by setting the combination of the cover plate and the housing 22, the electrical connection components and sealing components of the battery cell can be set at the cover plate. The housing 22, as the main structure of the battery cell shell, can be set to be relatively thin to reduce the overall weight as much as possible and increase the internal space of the battery cell to improve the volumetric energy density. More specifically, the explosion-proof valve and the positive and negative terminals of the battery cell are located on different surfaces, forming a thermoelectric separation effect. This prevents the heat generated by the positive and negative terminals during charging and discharging from being transferred to the explosion-proof valve, thus preventing the explosion-proof valve from bursting due to temperature rise. At the same time, it can prevent the gas discharged when the explosion-proof valve is depressurized from contacting the electrodes, preventing the gas from reacting with the electrodes to generate an electric arc or short circuit. This further improves battery safety while ensuring the functional stability of the explosion-proof valve.

[0047] In this embodiment, the battery cell housing provided in this embodiment has the same technical effect as the explosion-proof valve mentioned above, which will not be repeated here. At the same time, by setting the housing 22 and the cover plate, a closed and sealed internal space of the battery cell can be formed. Moreover, by welding the explosion-proof valve to the mounting hole 21 of the housing 22, that is, the explosion-proof valve and the cover plate are on different sides, the housing 22 can be designed to be thinner, reducing weight and increasing the internal space of the battery cell, thereby improving the volumetric energy density.

[0048] Optionally, such as Figures 4 to 6 As shown, the thickness of the shell 22 is 0.2 mm ≤ h < 0.6 mm.

[0049] Specifically, the thickness of the wall on the housing 22 where the explosion-proof valve is installed can be designed to be 0.2 mm ≤ h < 0.6 mm, for example, 0.2 mm, 0.3 mm, 0.4 mm, 0.55 mm, etc., depending on actual needs. The thickness of the remaining walls can be further adjusted according to actual needs, while ensuring the overall structural strength and functional requirements of the housing 22. It should be noted that when the thickness of the housing 22 is less than 0.2 mm, its structural strength may not meet the mechanical requirements of the battery cell casing; while when the thickness of the housing 22 reaches or exceeds 0.6 mm, conventional explosion-proof valve welding methods can effectively control the risk of weld burn-through, and the need to thin the housing to increase energy density is no longer urgent. The technical advantage of preventing weld burn-through through structural compensation in this embodiment is not significant outside this thickness range. Therefore, limiting the thickness of the housing 22 to the range of 0.2 mm ≤ h < 0.6 mm is the preferred and necessary technical means proposed in this embodiment to solve the technical contradiction of "thinning the housing and preventing weld burn-through".

[0050] In this embodiment, by setting the thickness of the shell 22 to 0.2 mm ≤ h < 0.6 mm, compared with the related technical solutions where the shell thickness is greater than 1 mm, the shell 22 is significantly thinner. This thinning of the shell 22 can achieve weight reduction and increase volumetric energy density. At the same time, the structure of welding and installing the explosion-proof valve ensures the safety of the battery.

[0051] Optionally, such as Figures 4 to 6 As shown, the housing 22 is a cuboid, with a narrow wall of the housing 22 protruding outward and forming a receiving groove on the inner side. The mounting hole 21 is opened in the bottom wall 221 of the receiving groove, and the outer ring plate 11 of the explosion-proof valve abuts against the bottom wall 221 of the receiving groove.

[0052] Specifically, the cuboid structure of the casing 22 means that the casing 22 is a regular hexahedral structure and a flat structure as a whole. One side or two opposite sides can be open, such as the cell casing of the blade battery. The narrow wall refers to the smaller wall. The receiving groove can be formed by stamping in the direction from the inside of the cell outward through the narrow wall. That is, the receiving groove and the casing 22 are an integral structure and the thickness is the same as the thickness of the casing 22. Its outward protrusion height is slightly higher than the plane of the casing 22. The protrusion height can be the same as the thickness of the outer ring plate 11, so that the depth of the receiving groove formed inside is also basically the same as the thickness of the outer ring plate 11, ensuring the neatness and integrity of the internal space of the cell after the outer ring plate 11 is installed in the receiving groove.

[0053] In this embodiment, by setting the housing 22 as a cuboid, the structure is more regular, which facilitates stacking or array assembly. By protruding outward on a narrow wall of the housing 22 and forming a receiving groove on the inner side, the mounting hole 21 is opened in the bottom wall 221 of the receiving groove. On the one hand, the receiving groove can form an installation reference for the explosion-proof valve, which facilitates the installation of the explosion-proof valve. On the other hand, the setting of the receiving groove reserves space for the installation of the explosion-proof valve, preventing the structure of the explosion-proof valve located inside the housing 22 from occupying the internal space of the battery cell, which further improves the volumetric energy density of the battery cell. At the same time, by abutting the outer ring plate 11 of the explosion-proof valve against the bottom wall 221 of the receiving groove, the structural strength of this part is enhanced, and a two-layer plate structure is provided for welding to prevent weld penetration and ensure overall safety.

[0054] In addition, another embodiment of the present invention provides a battery, including the explosion-proof valve and / or the cell housing described above.

[0055] For example, the battery is a blade battery, used as a power battery for new energy vehicles.

[0056] In this embodiment, the battery provided by this embodiment, by setting the aforementioned explosion-proof valve and / or the aforementioned cell casing, has roughly the same technical effects as the aforementioned explosion-proof valve and / or the aforementioned cell casing, and will not be described in detail here. Furthermore, assembling the aforementioned explosion-proof valve and / or the aforementioned cell casing into the corresponding battery is a common technical means that should be understood by those skilled in the art, and will not be specifically limited or described here.

[0057] On the other hand, another embodiment of the present invention provides an automobile, including the above-mentioned explosion-proof valve and / or the above-mentioned cell housing and / or the above-mentioned battery.

[0058] For example, the vehicle is a new energy vehicle.

[0059] In this embodiment, the vehicle provided by this embodiment, by incorporating the aforementioned explosion-proof valve and / or the aforementioned cell casing and / or the aforementioned battery, achieves technical effects substantially the same as those of the aforementioned explosion-proof valve and / or the aforementioned cell casing and / or the aforementioned battery, and will not be elaborated upon further here. Furthermore, assembling the aforementioned explosion-proof valve and / or the aforementioned cell casing and / or the aforementioned battery into the corresponding vehicle is a common technical means that should be understood by those skilled in the art, and will not be specifically limited or described here.

[0060] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.

Claims

1. An explosion-proof valve, characterized in that, The device includes a plate-shaped body and an annular boss (12) disposed on the plate-shaped body. The plate-shaped body includes an outer annular plate (11) located outside the annular boss (12) and surrounding the annular boss (12) and an inner annular plate (13) located inside the annular boss (12). The outer peripheral wall of the annular boss (12) is used to weld to the hole wall of the mounting hole (21) of the battery cell housing. The outer annular plate (11) is used to abut against the inner wall of the battery cell housing. The inner annular plate (13) is provided with grooves (14).

2. The explosion-proof valve according to claim 1, characterized in that, A weld (30) is formed at the connection between the outer peripheral wall of the annular boss (12) and the hole wall of the mounting hole (21), and the projection of the weld (30) on the plate-shaped body is entirely located within the plate-shaped body.

3. The explosion-proof valve according to claim 2, characterized in that, The outer contour of the outer ring plate (11) and the outer contour of the annular boss (12) are both adapted to the shape of the mounting hole (21). The mounting hole (21) is a waist-shaped hole. The projections of the starting end (31) and the ending end (32) of the weld (30) on the plate-shaped body are both located within the same arc segment (111) of the outer ring plate (11).

4. The explosion-proof valve according to claim 3, characterized in that, The width of the arc segment (111) of the outer ring plate (11) is greater than the width of the straight segment (112) of the outer ring plate (11).

5. The explosion-proof valve according to any one of claims 1-4, characterized in that, The groove (14) is opened along the outer edge of the inner ring plate (13), and the two ends of the groove (14) are spaced apart.

6. The explosion-proof valve according to any one of claims 2-4, characterized in that, The top surface of the annular boss (12) is configured such that, after welding, the inner ring profile of the weld (30) is located within the range of the top surface of the annular boss (12).

7. A battery cell casing, characterized in that, The device includes a housing (22), a cover plate, and an explosion-proof valve as described in any one of claims 1-6, wherein the housing (22) has a mounting hole (21), and the explosion-proof valve is welded to the mounting hole (21).

8. The battery cell casing according to claim 7, characterized in that, The thickness of the shell (22) is 0.2 mm ≤ h < 0.6 mm.

9. The battery cell casing according to claim 7, characterized in that, The housing (22) is cuboid, and a narrow wall of the housing (22) protrudes outward and forms a receiving groove on the inner side. The mounting hole (21) is opened in the bottom wall (221) of the receiving groove. The outer ring plate (11) of the explosion-proof valve is located in the receiving groove and abuts against the bottom wall (221) of the receiving groove.

10. A battery, characterized in that, Includes the explosion-proof valve as described in any one of claims 1-6 and / or the cell housing as described in any one of claims 7-9.

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