Single battery
By modifying the injection hole into an explosion-proof valve and combining it with the installation groove and weakening groove structure, rapid pressure relief of a single cell during thermal runaway was achieved, solving the problem of insufficient pressure relief capacity in the existing technology, improving safety and reducing costs.
Patent Information
- Application Number
- CN202422582708.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2034-10-24
AI Technical Summary
Existing single-cell batteries are difficult to depressurize quickly during thermal runaway, especially large-capacity or high-energy-density batteries, resulting in high design costs, complex processes, and difficulty in achieving rapid venting of explosion-proof valves.
A first explosion-proof valve and a second explosion-proof valve were designed. The first explosion-proof valve was modified by utilizing the existing injection hole area to ensure that high-temperature gas and liquid can be discharged simultaneously in the event of thermal runaway. The welding stability and pressure relief capacity were improved by installing a groove and weakening the groove structure.
It improves the pressure relief capacity of individual cells, enhances safety performance, and reduces costs and process complexity, while avoiding additional space occupation.
Smart Images
Figure CN223712872U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of batteries, and in particular to a single battery. BACKGROUND
[0002] Power batteries are core energy supply units in the field of new energy technology, and are currently widely used in vehicles and industrial machines. A power battery usually includes multiple single batteries, and the safety performance of a single battery is a problem that needs to be paid attention to in the development of new energy technology.
[0003] The prior art sets an explosion-proof valve on the shell of a single battery, which is used to discharge high-temperature gas and liquid when the single battery is in thermal runaway, so as to reduce the risk of explosion caused by thermal runaway of the single battery.
[0004] However, for some special single batteries, such as large-capacity batteries or high-energy-density batteries, a large amount of gas will be generated in a short period of time when they are in thermal runaway, which makes it difficult for the explosion-proof valve to achieve rapid discharge. The additional design of the explosion-proof valve will increase the cost and complicate the production process.
[0005] SUMMARY
[0006] The present application provides a single battery to improve the pressure relief capacity of the single battery while taking into account the economy.
[0007] A single battery includes a shell, an electric core assembly, and a first explosion-proof valve and a second explosion-proof valve. The shell includes a shell body and a top cover plate, the shell body has an open accommodating cavity, and the top cover plate is arranged on the opening to close the accommodating cavity. The electric core assembly is arranged in the accommodating cavity. The first explosion-proof valve and the second explosion-proof valve are both arranged on the shell. The top cover plate is provided with a liquid injection hole, the first explosion-proof valve is sealingly arranged in the liquid injection hole, and the second explosion-proof valve is arranged on the shell body.
[0008] In the embodiments of the present application, the shell of the single battery is designed with a first explosion-proof valve and a second explosion-proof valve. When the single battery is in thermal runaway, the high-temperature gas and liquid in the accommodating cavity can be discharged from the first explosion-proof valve and the second explosion-proof valve at the same time, which effectively increases the pressure relief capacity of the single battery and improves the safety performance. Moreover, the first explosion-proof valve utilizes the area of the liquid injection hole, which makes the first explosion-proof valve simultaneously serve the functions of sealing the liquid injection hole and relieving pressure and explosion, without occupying additional space. Finally, the first explosion-proof valve is not designed additionally, but is formed by modifying the end cover that originally seals the liquid injection hole, which is conducive to reducing the cost and simplifying the process.
[0009] As one of the optional embodiments of the present application, the top cover plate has a top surface facing away from the accommodating cavity, the top cover plate is recessed from the top surface to form a mounting groove, and the first explosion-proof valve is embedded in the mounting groove.
[0010] As one of the optional embodiments of the present application, the installation groove has a groove bottom surface, and the liquid injection hole penetrates through the top cover plate from the groove bottom surface and communicates with the accommodating cavity.
[0011] In the embodiment of the present application, the installation groove is arranged on the top cover plate to form a counterbore structure, which enables the first explosion-proof valve to be stably placed on the top cover plate when the first explosion-proof valve is installed, thereby ensuring the stability of the first explosion-proof valve when the first explosion-proof valve is welded and fixed, and helping to stably and accurately weld.
[0012] As one of the optional embodiments of the present application, a weakened groove is arranged on the side of the first explosion-proof valve close to the accommodating cavity, and the top surface projection of the weakened groove at least partially overlaps the top surface projection of the liquid injection hole.
[0013] In the embodiment of the present application, the design of the weakened groove can reduce stress concentration when the first explosion-proof valve is welded, which is conducive to the stable implementation of welding and the reliable welding of the welding portion and the installation groove, thereby realizing the function of stably sealing the liquid injection hole. The above design of the weakened groove can ensure that the first explosion-proof valve is thinned in the area that needs to be broken, thereby facilitating the corresponding area to be broken and smooth pressure relief when the single battery is in thermal runaway.
[0014] As one of the optional embodiments of the present application, the first explosion-proof valve comprises a main body portion and a protruding portion connected to each other, the main body portion is embedded in the installation groove, the protruding portion is protruding on the side of the main body portion away from the accommodating cavity, a weak portion is arranged on the protruding portion, and the top surface projection of the protruding portion at least partially overlaps the top surface projection of the liquid injection hole.
[0015] In the embodiment of the present application, the first explosion-proof valve needs to be welded and fixed in the installation groove after the liquid injection is completed. During the process of placing the first explosion-proof valve in the installation groove and the welding operation, the electrolyte in the accommodating cavity or the residual electrolyte in the installation groove may be extruded by the first explosion-proof valve and overflow from the peripheral side of the first explosion-proof valve, which may cause the electrolyte to flow to the weak portion, resulting in corrosion of the weak portion and affecting the structural strength. In the embodiment of the present application, the structure of the first explosion-proof valve is designed as a main body portion and a protruding portion with a height higher than that of the main body portion, which makes the weak portion higher than the main body portion, thereby reducing the pollution of the weak portion by the electrolyte and ensuring the structural reliability of the first explosion-proof valve.
[0016] As one of the optional embodiments of the present application, the top surface projection of the weakened groove covers the top surface projection of the weak portion.
[0017] In the embodiment of the present application, the above design of the weakened groove can ensure that the first explosion-proof valve is thinned in the area corresponding to the weak portion, thereby facilitating the corresponding area to be broken and smooth pressure relief when the single battery is in thermal runaway.
[0018] As one of the optional embodiments of this application, the weak part is set as a recessed groove on the protrusion.
[0019] As one of the optional embodiments of this application, the first explosion-proof valve further includes a welding part, which protrudes from one side of the main body away from the accommodating cavity, surrounds the outer periphery of the protrusion, and is spaced apart from the welding part to form a gap groove.
[0020] In this embodiment, the welding part is used to weld and fix the main body part into the mounting groove. A spacer groove is formed between the welding part and the protrusion, which makes it possible for some electrolyte to preferentially converge into the spacer groove even if some electrolyte overflows from the welding part, thereby reducing the electrolyte from flowing onto the protrusion.
[0021] As one of the optional embodiments of this application, the mounting groove has a peripheral side surface, which together with the bottom surface of the groove forms the mounting groove. Along the direction away from the bottom surface of the groove, the peripheral side surface is inclined in the direction away from the first explosion-proof valve. The main body has an outer peripheral surface facing the peripheral side surface, which is fitted to the peripheral side surface.
[0022] In this embodiment, the peripheral side of the mounting groove is inclined, making it easier for the main body to be placed in the mounting groove. Furthermore, the inclined peripheral side increases the contact area between the main body and the mounting groove, resulting in more stable welding.
[0023] As one of the optional embodiments of this application, the welding part is located on the side of the top surface near the receiving cavity. The welding part has a welding surface facing the peripheral side. The side of the welding surface that is connected to the main body is in contact with the peripheral side. Along the direction away from the main body, the welding surface is gradually inclined away from the peripheral side.
[0024] In this embodiment, one edge of the welded part contacts the peripheral side surface, which allows the portion of the inner wall of the mounting groove corresponding to the welded part to melt during welding, thereby forming a weld mark together with the welded part. This is beneficial for the full formation of the weld mark and makes the welding sealing structure more reliable and stable. Meanwhile, the other side gradually moves away from the peripheral side surface, leaving a welding allowance between the welded surface and the peripheral side surface, which is beneficial for the formation of the weld mark.
[0025] One of the above technical solutions has the following advantages or beneficial effects: the casing of the single battery is designed with a first explosion-proof valve and a second explosion-proof valve. When the single battery experiences thermal runaway, the high-temperature gas and liquid in the containment cavity can be discharged simultaneously from the first and second explosion-proof valves, which effectively increases the pressure relief capacity of the single battery and improves its safety performance; the first explosion-proof valve utilizes the area of the injection hole, which allows the first explosion-proof valve to simultaneously seal the injection hole and relieve pressure for explosion protection without occupying additional space; finally, the first explosion-proof valve is not an additional design, but rather the end cap that originally sealed the injection hole is modified to form the first explosion-proof valve, which helps to reduce costs and process complexity. Attached Figure Description
[0026] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.
[0027] Figure 1 This is an exploded view of the overall structure of a single battery cell provided in the embodiments of this application;
[0028] Figure 2 This is a schematic diagram provided in an embodiment of this application, mainly used to illustrate the structure of the top cover plate;
[0029] Figure 3 This is a cross-sectional view provided in an embodiment of this application to illustrate the installation structure of the first explosion-proof valve and the top cover plate;
[0030] Figure 4 This is provided by the embodiments of this application. Figure 3 A magnified view of part A in the middle;
[0031] Figure 5 This is a cross-sectional view provided in an embodiment of this application, showing the first explosion-proof valve installed in the mounting groove;
[0032] Figure 6 This is a schematic diagram provided in an embodiment of this application to illustrate the overall structure of the first explosion-proof valve.
[0033] Reference numerals: 1. Outer shell; 11. Housing; 111. Frame; 112. Bottom cover plate; 12. Top cover plate; 121. Top surface; 10. Receiving cavity;
[0034] 2. Battery cell assembly; 21. Positive tab; 22. Negative tab;
[0035] 3. First explosion-proof valve; 31. Main body; 311. Outer peripheral surface; 32. Protrusion; 321. Weak part; 33. Welded part; 331. Welded surface;
[0036] 4. Second explosion-proof valve;
[0037] 51. Injection hole; 52. Mounting groove; 521. Bottom surface of the groove; 522. Peripheral side surface;
[0038] 6. Spacing groove; 7. Weakening groove;
[0039] 8. Electrode; 81. Positive electrode; 82. Negative electrode;
[0040] 9. Place the plastic sheet on top. Detailed Implementation
[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0042] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Furthermore, the character " / " in this document, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.
[0043] The following is in conjunction with the appendix Figures 1-6 This application will be further described below.
[0044] Reference Figure 1 and Figure 2 This application discloses a single-cell battery, which includes a housing 1, a cell assembly 2 disposed within the housing 1, and a first explosion-proof valve 3 and a second explosion-proof valve 4 both disposed on the housing 1. The housing 1 includes a shell 11 and a top cover plate 12. The shell 11 has an open receiving cavity 10, and the top cover plate 12 covers the open cavity to close it. The top cover plate 12 has a liquid injection hole 51, the first explosion-proof valve 3 is sealed at the liquid injection hole 51, and the second explosion-proof valve 4 is disposed on the shell 11.
[0045] In this embodiment, the casing 1 of the single battery is designed with a first explosion-proof valve 3 and a second explosion-proof valve 4. When the single battery experiences thermal runaway, the high-temperature gas and liquid in the accommodating cavity 10 can be discharged simultaneously from the first explosion-proof valve 3 and the second explosion-proof valve 4. This effectively increases the pressure relief capacity of the single battery to improve safety performance. Furthermore, the first explosion-proof valve 3 utilizes the area of the injection hole 51, which allows the first explosion-proof valve 3 to simultaneously seal the injection hole 51 and relieve pressure and prevent explosion, without occupying additional space.
[0046] For example, in some high-capacity single-cell batteries, the liquid injection hole 51 and the electrode 8 are usually both located on the top cover plate 12. Due to the high overcurrent intensity of high-capacity single-cell batteries, the electrode 8 is designed to be large, thus occupying a large area of the top cover plate 12. This makes it difficult to design an additional explosion-proof valve on the top cover plate 12. Therefore, the first explosion-proof valve 3 utilizes the area of the liquid injection hole 51, without the need for additional openings or space occupation, effectively improving processing convenience and economy. Finally, the first explosion-proof valve 3 is not an additional design, but rather the end cap that originally sealed the liquid injection hole 51 is modified to form the first explosion-proof valve 3, which helps to reduce costs and process complexity.
[0047] In one example, specifically, the single battery cell is rectangular in shape, and the casing 11 includes a rectangular frame 111 and a bottom cover 112. Both ends of the frame 111 are open. The bottom cover 112 covers and seals one open end of the frame 111 to form a receiving cavity 10, and the top cover 12 covers the other open end of the frame 111 to close the receiving cavity 10. Exemplarily, both the bottom cover 112 and the top cover 12 are welded to the frame 111 to achieve a seal.
[0048] Reference Figure 1 and Figure 2 Electrode 8 is disposed on top cover plate 12. Electrode 8 includes a positive electrode 81 and a negative electrode 82, which penetrate the top cover plate 12 and partially extend into the receiving cavity 10. Cell assembly 2 includes a positive electrode sheet, a separator, and a negative electrode sheet, which are sequentially stacked or wound to form cell assembly 2. Cell assembly 2 has a positive electrode tab 21 and a negative electrode tab 22 facing one end of top cover plate 12. The positive electrode tab 21 is connected to the positive electrode 81 to achieve electrical conduction, and the negative electrode tab 22 is electrically connected to the negative electrode 82 to achieve electrical conduction. For example, the positive electrode tab 21 and the positive electrode 81 are welded together via an adapter piece or directly welded together.
[0049] It should be noted that an upper plastic plate 9 is also provided on the side of the top cover plate 12 facing the receiving cavity 10. The upper plastic plate 9 serves as an insulating support, which is existing technology and will not be described in detail here.
[0050] The second explosion-proof valve 4 is disposed on the bottom cover plate 112. In one example, the bottom cover plate 112 has an explosion-proof hole communicating with the accommodating cavity 10. The second explosion-proof valve 4 is a sheet-like structure with recessed grooves. The peripheral edge of the second explosion-proof valve 4 is welded to the explosion-proof hole. In other alternative embodiments, the second explosion-proof valve 4 can also be integrally formed as part of the bottom cover plate 112. For example, a portion of the bottom cover plate 112 can be stamped with indentations using a stamping machine, and the area enclosed by the indentations can be considered as the second explosion-proof valve 4. It should be noted that the second explosion-proof valve 4 can also be disposed in other parts of the housing 11, such as the wall panel of the frame 111.
[0051] Reference Figures 3-5 As one of the optional embodiments of this application, the top cover plate 12 has a top surface 121 facing away from the accommodating cavity 10, and the top cover plate 12 is recessed from the top surface 121 to provide an installation groove 52, in which the first explosion-proof valve 3 is embedded; wherein, the installation groove 52 has a bottom surface 521, and the injection hole 51 extends from the bottom surface 521 through the top cover plate 12 and communicates with the accommodating cavity 10.
[0052] Specifically, the mounting groove 52 is circular, and the first explosion-proof valve 3 is generally circular in shape. When the first explosion-proof valve 3 is placed in the mounting groove 52, the first explosion-proof valve 3 is located on the side of the top surface 121 near the receiving cavity 10, which facilitates the smooth welding process and makes the first explosion-proof valve 3 look more aesthetically pleasing after welding.
[0053] In this embodiment, the top cover plate 12 is provided with an installation groove 52 to form a countersunk hole structure, which enables the first explosion-proof valve 3 to be stably placed on the top cover plate 12 when installing the first explosion-proof valve 3, thereby ensuring the stability of the first explosion-proof valve 3 when welding and fixing it, which helps to stabilize and accurately weld.
[0054] Reference Figure 4 and Figure 6 As one of the optional embodiments of this application, the first explosion-proof valve 3 includes a main body 31 and a protrusion 32 connected to each other. The main body 31 is embedded in the mounting groove 52, and the protrusion 32 protrudes from the side of the main body 31 away from the receiving cavity 10. A weak part 321 is provided on the protrusion 32, and the orthographic projection of the protrusion 32 on the top surface 121 at least partially overlaps with the orthographic projection of the injection hole 51 on the top surface 121.
[0055] Specifically, the main body 31 and the protrusion 32 are integrally connected, and the main body 31 and the protrusion 32 are arranged along the axial direction of the injection hole 51. Both the main body 31 and the protrusion 32 are provided as circular plates and are arranged coaxially. In one example, the orthographic projection of the protrusion 32 on the top surface 121 covers the orthographic projection of the injection hole 51 on the top surface 121.
[0056] In this embodiment, after the liquid injection is completed, the first explosion-proof valve 3 needs to be welded and fixed in the mounting groove 52. When the first explosion-proof valve 3 is placed in the mounting groove 52 and during the welding operation, the electrolyte in the accommodating cavity 10 or the electrolyte remaining in the mounting groove 52 may be squeezed by the first explosion-proof valve 3 and overflow from the periphery of the first explosion-proof valve 3. This may cause the electrolyte to flow to the weak part 321, causing corrosion of the weak part 321 and thus affecting the structural strength. In this embodiment, the structure of the first explosion-proof valve 3 is designed as a main body 31 and a protrusion 32 that is higher than the main body 31. This makes the weak part 321 higher than the main body 31, thereby reducing electrolyte contamination of the weak part 321 and ensuring the structural reliability of the first explosion-proof valve 3.
[0057] As one optional embodiment of this application, the weak portion 321 is set as a recessed groove on the protrusion 32. Specifically, in one example, the weak portion 321 is generally annular, and the cross-section of the weak portion 321 along the vertical section plane is an inverted triangle. In other optional embodiments, the cross-section of the weak portion 321 can also be an inverted trapezoid, an arc, etc., and the number and form are not limited to rectangles.
[0058] As one optional embodiment of this application, the first explosion-proof valve 3 further includes a welding portion 33, which protrudes from the side of the main body 31 away from the accommodating cavity 10. The welding portion 33 surrounds the outer periphery of the protrusion 32, and a spacer groove 6 is formed between the welding portion 33 and the protrusion 32. Specifically, the welding portion 33 is integrally connected to the main body 31, and the welding portion 33 is generally annularly arranged around the outer periphery of the protrusion 32.
[0059] In this embodiment, the welding part 33 is used to weld and fix the main body part 31 in the mounting groove 52. A spacer groove 6 is formed between the welding part 33 and the protrusion 32. This makes it possible for some electrolyte to overflow from the welding part 33 to preferentially collect in the spacer groove 6, thereby reducing the corrosion damage to the protrusion 32 caused by the electrolyte flowing onto it.
[0060] As one optional embodiment of this application, a weakening groove 7 is recessed on one side of the main body 31 near the receiving cavity 10. The orthographic projection of the weakening groove 7 on the top surface 121 at least partially overlaps with the orthographic projection of the injection hole 51 on the top surface 121. Specifically, the orthographic projection of the weakening groove 7 on the top surface 121 covers the orthographic projection of the weak portion 321 on the top surface 121.
[0061] In this embodiment, the design of the weakening groove 7 reduces stress concentration during welding of the first explosion-proof valve 3, which is beneficial to the stable welding. Furthermore, the above design makes the edge thickness of the main body 31 greater than the thickness of the protrusion 32 region. For the first explosion-proof valve 3, a thicker edge design helps ensure reliable welding between the first explosion-proof valve 3 and the mounting groove 52, thereby achieving a reliable seal of the injection hole 51. Conversely, a thinner protrusion 32 region facilitates the destruction of the corresponding area of the weak point 321 during thermal runaway of a single battery, thus promoting smooth pressure relief.
[0062] It should be noted that in this embodiment, the maximum overall thickness of the first explosion-proof valve 3 is D mm, satisfying D≤4, and the minimum distance between the weak part 321 and the top surface of the weakening groove 7 is h, satisfying h≤0.3 mm. The purpose of the above design is to ensure that the first explosion-proof valve 3 can meet the strength requirements for welding and sealing the injection hole 51 while also meeting the strength requirements for pressure to break through the first explosion-proof valve 3. In other optional examples, D and h can be designed according to actual conditions, such as the pressure inside the single cell during thermal runaway.
[0063] Reference Figure 4 , Figure 5 and Figure 6As one of the optional embodiments of this application, the mounting groove 52 has a peripheral side surface 522, which together with the bottom surface 521 forms the mounting groove 52. Along the direction away from the bottom surface 521, the peripheral side surface 522 is inclined in the direction away from the first explosion-proof valve 3. The main body 31 has an outer peripheral surface 311 facing the peripheral side surface 522, which is fitted to the peripheral side surface 522.
[0064] In this embodiment, the peripheral side 522 of the mounting groove 52 is inclined, making it easier for the main body 31 to be placed in the mounting groove 52. Furthermore, the inclined peripheral side 522 increases the contact area between the main body 31 and the mounting groove 52, resulting in more stable welding.
[0065] As one of the optional embodiments of this application, the welding part 33 is located on the side of the top surface 121 near the receiving cavity 10. The welding part 33 has a welding surface 331 facing the peripheral side surface 522. The side of the welding surface 331 that is connected to the main body part 31 contacts the peripheral side surface 552. Along the direction away from the main body part 31, the welding surface 331 is gradually inclined away from the peripheral side surface 552.
[0066] In this embodiment, one edge of the welding part 33 contacts the peripheral side surface 522, which allows the portion of the inner wall of the mounting groove 52 corresponding to the welding part 33 to melt during welding, thereby forming a weld mark together with the welding part 33. This is beneficial for the full formation of the weld mark and makes the welding sealing structure more reliable and stable. Meanwhile, the other side of the welding surface 331 gradually moves away from the peripheral side surface 522, leaving a welding allowance between the welding surface 331 and the peripheral side surface 522, which is beneficial for the formation of the weld mark and the smooth progress of the welding operation.
[0067] On the other hand, this application also provides a battery pack including the single cell described above.
[0068] The above description is only a partial implementation of the embodiments of this application and is not intended to limit the application in any way. The protection scope of the embodiments of this application is not limited thereto. Any simple modifications, equivalent changes and alterations that can be easily conceived by those skilled in the art within the technical scope disclosed in the embodiments of this application should be included within the protection scope of the embodiments of this application.
Claims
1. A single-cell battery, characterized in that, include: The outer casing (1) includes a housing (11) and a top cover (12), the housing (11) having an open receiving cavity (10), the top cover (12) covering the open to close the receiving cavity (10); the top cover (12) has a top surface (121) facing away from the receiving cavity (10); The battery cell assembly (2) is disposed within the accommodating cavity (10); and, The first explosion-proof valve (3) and the second explosion-proof valve (4) are both disposed on the outer shell (1); a weakening groove (7) is recessed on the side of the first explosion-proof valve (3) near the accommodating cavity (10); The top cover plate (12) is provided with a liquid injection hole (51), the first explosion-proof valve (3) is sealed in the liquid injection hole (51), and the second explosion-proof valve (4) is provided in the housing (11); the orthographic projection of the weakening groove (7) on the top surface (121) and the orthographic projection of the liquid injection hole (51) on the top surface (121) at least partially overlap.
2. The single-cell battery as described in claim 1, characterized in that, The top cover plate (12) has a recessed mounting groove (52) on the top surface (121), and the first explosion-proof valve (3) is embedded in the mounting groove (52).
3. The single-cell battery as described in claim 2, characterized in that, The mounting groove (52) has a bottom surface (521), and the injection hole (51) extends from the bottom surface (521) through the top cover plate (12) and communicates with the accommodating cavity (10).
4. The single-cell battery as described in claim 2, characterized in that, The first explosion-proof valve (3) includes a main body (31) and a protrusion (32) connected to each other. The main body (31) is embedded in the mounting groove (52). The protrusion (32) protrudes from the side of the main body (31) away from the accommodating cavity (10). The protrusion (32) is provided with a weak part (321). The orthographic projection of the protrusion (32) on the top surface (121) at least partially overlaps with the orthographic projection of the injection hole (51) on the top surface (121).
5. The single-cell battery as described in claim 4, characterized in that, The orthographic projection of the weakening groove (7) on the top surface (121) covers the orthographic projection of the weak part (321) on the top surface (121).
6. The single-cell battery as described in claim 4, characterized in that, The weak part (321) is configured as a recessed groove on the protrusion (32).
7. The single-cell battery as described in claim 4, characterized in that, The first explosion-proof valve (3) further includes a welding part (33), which protrudes from the side of the main body (31) away from the accommodating cavity (10). The welding part (33) surrounds the outer periphery of the protrusion (32), and the welding part (33) and the protrusion (32) are spaced apart to form a spacer groove (6).
8. The single-cell battery as described in claim 7, characterized in that, The mounting groove (52) has a bottom surface (521) and a peripheral side surface (522). The peripheral side surface (522) and the bottom surface (521) together form the mounting groove (52). Along the direction away from the bottom surface (521), the peripheral side surface (522) is inclined in the direction away from the first explosion-proof valve (3). The main body (31) has an outer peripheral surface (311) facing the peripheral side surface (522). The outer peripheral surface (311) is fitted to the peripheral side surface (522).
9. The single-cell battery as described in claim 8, characterized in that, The welding part (33) has a welding surface (331) facing the peripheral side surface (522). The side of the welding surface (331) connected to the main body part (31) contacts the peripheral side surface (522). Along the direction away from the main body part (31), the welding surface (331) is gradually inclined away from the peripheral side surface (522).