Battery and battery pack

Abstract

A battery and a battery pack. The battery comprises a housing (1) and at least one explosion-proof valve assembly (2) provided on the housing (1); a mounting hole (101) is formed on the housing (1); the explosion-proof valve assembly (2) comprises an explosion-proof valve (201) and a protective layer (202); the explosion-proof valve (201) is arranged in the mounting hole (101); an exposure area exposed outside the mounting hole (101) is present at the end surface of the explosion-proof valve (201) close to the inner cavity of the housing (1); the protective layer (202) is arranged on the explosion-proof valve and covers the exposure area of the explosion-proof valve (201), so as to isolate the explosion-proof valve (201) from the inner cavity of the housing (1); the protective layer (202) is adapted to be softened when a temperature exceeds a set temperature, so that the explosion-proof valve (201) can be opened when air pressure exceeds set pressure. According to the battery and the battery pack, the protective layer (202) can isolate the explosion-proof valve (201) from an electrolyte in the housing (1), thereby effectively preventing the valve opening stability of the explosion-proof valve (201) from being affected by corrosion of the explosion-proof valve (201) due to being in contact with the electrolyte, and improving the safety performance of the battery; when the temperature rises and exceeds the set temperature, the protective layer (202) is softened, and the explosion-proof valve (201) is allowed to smoothly burst when the air pressure in the battery is increased.

Description

Batteries and battery packs

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application number 202321678922.9, entitled “Batteries and Battery Packs,” filed with the Chinese Patent Office on June 29, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to batteries and battery packs. Background Art

[0004] With the continuous development of technology, users' requirements for new energy batteries are getting higher and higher.

[0005] When a battery cell operates abnormally and gas is generated inside, it is necessary to release the pressure through an explosion-proof valve and discharge the gas in time to avoid major safety accidents and improve the safety performance of the battery.

[0006] When the battery cell is manufactured, the residual electrolyte inside will cause the explosion-proof valve to be immersed in the electrolyte for a long time. The electrolyte will corrode the explosion-proof valve, thereby affecting the stable opening of the explosion-proof valve and even causing the explosion-proof valve to fail, thereby posing a huge safety hazard to the battery cell.

[0007] Application Contents

[0008] In view of this, the present application provides a battery and a battery pack to solve the problem that the explosion-proof valve is easily corroded when in contact with the electrolyte and the battery has low safety.

[0009] In a first aspect, the present application provides a battery, comprising a shell and at least one explosion-proof valve assembly provided on the shell, wherein the shell is provided with a mounting hole; the explosion-proof valve assembly comprises an explosion-proof valve and a protective layer, the explosion-proof valve is provided in the mounting hole, and an end face of the explosion-proof valve close to the inner cavity of the shell has an exposed area exposed to the mounting hole, the protective layer is provided on and covers the exposed area of ​​the explosion-proof valve to isolate the explosion-proof valve from the inner cavity of the shell, and the protective layer is suitable for softening when the temperature exceeds a set temperature so that the explosion-proof valve can open when the air pressure exceeds a set pressure.

[0010] Beneficial effects: By setting a protective layer, since the protective layer is arranged on the explosion-proof valve and covers the exposed area, the explosion-proof valve and the inner cavity of the shell are isolated, that is, the explosion-proof valve is isolated from the electrolyte in the shell, effectively preventing the explosion-proof valve from being corroded due to contact with the electrolyte, thereby affecting the valve opening stability of the explosion-proof valve, and improving the safety performance of the battery; since the protective layer will only soften when the set temperature is exceeded, the protective layer can play a good isolation role at room temperature; in addition, before the explosion-proof valve is opened, an abnormality usually occurs inside the battery and the temperature rises. When the temperature rises above the set temperature, the protective layer softens, allowing the explosion-proof valve to open smoothly when the air pressure inside the battery increases.

[0011] In an optional embodiment, the protective layer includes a protective layer body and extensions located on both sides of the protective layer body. The protective layer body is arranged on the end face of the explosion-proof valve close to the shell cavity, and the extensions are at least attached to the inner wall of the mounting hole.

[0012] Beneficial effect: With this arrangement, the extension portion of the protective layer is connected to the shell, which can improve the connection stability between the protective layer and the explosion-proof valve and the shell.

[0013] In an optional embodiment, a groove is provided at one end of the mounting hole away from the inner cavity of the shell, the explosion-proof valve is arranged in the groove, a step structure is formed between the exposed area and the end face of the mounting hole, and the extension portion is attached to the inner wall of the mounting hole and extends toward the inner wall of the shell.

[0014] Beneficial Effects: By providing a groove and positioning the explosion-proof valve within it, the valve is positioned to limit its position, improving the stability of the connection between the valve and the mounting hole. Due to the groove, a stepped structure is formed between the exposed area and the end face of the mounting hole, while the extension adheres to the inner wall of the mounting hole and extends toward the inner wall of the housing, further improving the stability of the connection between the protective layer, the explosion-proof valve, and the housing.

[0015] In an optional embodiment, multiple explosion-proof valve assemblies are provided and are arranged on the same side wall of the shell, and the protective layers of the multiple explosion-proof valve assemblies are interconnected or integrally formed.

[0016] Beneficial effect: This arrangement can further improve the structural strength of the protective layer and the connection strength between the protective layer and the shell and explosion-proof valve.

[0017] In an optional embodiment, the thickness of the protective layer is 0.01 mm to 0.5 mm.

[0018] Beneficial effect: The thickness of the protective layer is controlled within this range, the protective layer is easy to form and the waterproof performance of the protective layer can be guaranteed, while saving costs.

[0019] In an optional embodiment, the explosion-proof valve includes an explosion-proof valve body and a weak area, the thickness of the weak area is smaller than the explosion-proof valve body, the weak area is arranged in the mounting hole, and the size of the mounting hole is larger than the size of the weak area.

[0020] Beneficial effect: With this arrangement, when the temperature rises and exceeds the set temperature and the protective layer softens, the weak area becomes the effective pressure relief area of ​​the explosion-proof valve and can fully contact the gas. The size of the installation hole is larger than the size of the weak area and will not limit the pressure relief area of ​​the weak area.

[0021] In an optional embodiment, the shell includes two oppositely arranged first walls and a second wall connecting the two first walls with a long side, the area of ​​the second wall is smaller than the area of ​​the first wall, and the explosion-proof valve assembly is arranged on the second wall.

[0022] Beneficial effect: With this arrangement, when abnormal heat occurs inside the battery and a large amount of gas is generated, the gas moves along the width direction of the shell to the explosion-proof valve assembly. Compared with the technical solution in which the explosion-proof valve assembly is arranged on the two end covers along the length direction of the shell, this arrangement has a shorter gas movement path, which is conducive to timely and rapid discharge of gas and explosive pressure relief.

[0023] In an optional embodiment, the set temperature is in the range of 50°C to 200°C.

[0024] Beneficial Effects: This temperature is significantly higher than room temperature, preventing the protective layer from softening within the battery's normal operating temperature range, ensuring that the protective layer effectively isolates the explosion-proof valve from the electrolyte. Furthermore, when the temperature exceeds the set temperature, it is highly likely that an internal battery short circuit or other abnormality has occurred, causing the battery to heat up. The softening of the protective layer at this temperature does not affect the normal opening and pressure relief of the explosion-proof valve, thus ensuring the safety of the battery.

[0025] In an optional embodiment, the set pressure is 0.2 MPa.

[0026] Beneficial effect: The set pressure is set to 0.2Mpa, and when abnormal gas is generated inside the battery, the pressure will be significantly greater than 0.2Mpa, thereby ensuring that the protective layer will not affect the normal opening and pressure relief of the explosion-proof valve.

[0027] In an optional embodiment, the material of the protective layer includes PE, PP, PET or glue.

[0028] Beneficial effect: The protective layer is made of this material, which can meet the above requirements, that is, it has sufficient strength at room temperature to prevent the explosion-proof valve from contacting the electrolyte, and can soften when the temperature is greater than 150°, so that even an air pressure of 0.2Mpa can break through the protective layer, ensuring the normal opening and pressure relief of the explosion-proof valve.

[0029] In a second aspect, the present application also provides a battery pack comprising multiple batteries described in any one of the above technical solutions.

[0030] Since the battery pack includes batteries and has the same effect as the batteries, it will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] FIG1 is an isometric view of a battery according to an embodiment of the present application;

[0033] FIG2 is an isometric view of the battery housing and explosion-proof valve assembly shown in FIG1 ;

[0034] FIG3 is a schematic diagram of the exploded structure of FIG2 ;

[0035] FIG4 is a top view of FIG2 ;

[0036] FIG5 is a cross-sectional view along AA in FIG4 ;

[0037] FIG6 is a partial enlarged view of the explosion-proof valve assembly in FIG5 ;

[0038] FIG7 is a schematic diagram of the exploded structure of an explosion-proof valve assembly and a housing in another embodiment of the present application;

[0039] FIG8 is a top view of FIG7;

[0040] FIG9 is a cross-sectional view along line BB in FIG8 ;

[0041] FIG10 is a partial enlarged view of the explosion-proof valve assembly in FIG9;

[0042] FIG11 is a schematic diagram of the exploded structure of a battery according to an embodiment of the present application.

[0043] Explanation of the accompanying drawings: 1. Shell; 101. Mounting hole; 1011. Groove; 102. First wall; 103. Second wall; 2. Explosion-proof valve assembly; 201. Explosion-proof valve; 2011. Explosion-proof valve body; 2012. Weak area; 202. Protective layer; 2021. Protective layer body; 2022. Extension; 3. Cover plate; 4. Pole group; 5. Side plate; 501. Heat dissipation channel; 6. Insulation film. DETAILED DESCRIPTION

[0044] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0045] The following describes an embodiment of the present application with reference to FIG1 to FIG11.

[0046] According to an embodiment of the present application, on the one hand, a battery is provided, referring to Figures 1 to 3, comprising a shell 1 and at least one explosion-proof valve assembly 2 provided on the shell 1, the shell 1 being provided with a mounting hole 101; the explosion-proof valve assembly 2 comprising an explosion-proof valve 201 and a protective layer 202, the explosion-proof valve 201 being provided in the mounting hole 101, and an exposed area exposed to the mounting hole 101 is present on the end face of the explosion-proof valve 201 close to the inner cavity of the shell 1, the protective layer 202 being provided on and covering the exposed area of ​​the explosion-proof valve 201 to isolate the explosion-proof valve 201 from the inner cavity of the shell 1, the protective layer 202 being adapted to soften when the temperature exceeds a set temperature so that the explosion-proof valve 201 explodes when the air pressure exceeds a set pressure.

[0047] By providing the protective layer 202, since the protective layer 202 is provided on the explosion-proof valve 201 and covers the exposed area, the explosion-proof valve 201 and the inner cavity of the shell 1 are isolated, that is, the explosion-proof valve 201 is isolated from the electrolyte in the shell 1, effectively preventing the explosion-proof valve 201 from being corroded due to contact with the electrolyte, affecting the valve opening stability of the explosion-proof valve 201, and improving the safety performance of the battery; since the protective layer 202 will only soften when the set temperature is exceeded, the protective layer 202 can play a good isolation role at room temperature; in addition, before the explosion-proof valve 201 is opened, an abnormality usually occurs inside the battery and the temperature rises. When the temperature rises above the set temperature, the protective layer 202 softens, allowing the explosion-proof valve 201 to open smoothly when the air pressure inside the battery increases.

[0048] In one embodiment, referring to FIG. 4 to FIG. 6 , the shape of the protective layer 202 matches the shape of the mounting hole 101 , and the protective layer 202 only covers the exposed area of ​​the explosion-proof valve 201 .

[0049] In one embodiment, referring to Figures 7 to 10, the protective layer 202 includes a protective layer body 2021 and extensions 2022 located on both sides of the protective layer body 2021. The protective layer body 2021 is arranged on the end surface of the explosion-proof valve 201 close to the inner cavity of the shell 1, and the extensions 2022 are attached to the inner wall of the mounting hole 101 and extend toward the inner wall of the shell 1.

[0050] With this arrangement, the extension portion 2022 of the protective layer 202 is connected to the housing 1 , which can improve the connection stability between the protective layer 202 and the explosion-proof valve 201 and the housing 1 .

[0051] Specifically, referring to Figure 10 , the protective layer body 2021 extends to connect with the inner wall of the mounting hole 101. That is, the inner wall of the housing 1, the inner wall of the mounting hole 101, and the exposed area of ​​the explosion-proof valve 201 are all provided with the protective layer 202. Because the thickness of the explosion-proof valve body 2011 is less than the depth of the mounting hole 101, a stepped structure is formed between the bottom of the explosion-proof valve body 2011 and the mounting hole 101. The stepped structure is tightly fitted with the protective layer 202, which increases the strength and stability of the connection between the protective layer 202, the explosion-proof valve 201, and the housing 1.

[0052] In one embodiment, a groove 1011 is provided at one end of the mounting hole 101 away from the inner cavity of the shell 1, and the explosion-proof valve 201 is arranged in the groove 1011. A step structure is formed between the exposed area and the end face of the mounting hole 101, and the extension portion 2022 is attached to the inner wall of the mounting hole 101 and extends toward the inner wall of the shell 1.

[0053] By providing groove 1011 and positioning explosion-proof valve 201 within groove 1011, explosion-proof valve 201 is restrained, thereby improving the stability of the connection between explosion-proof valve 201 and mounting hole 101. Due to the provision of groove 1011, a stepped structure is formed between the exposed area and the end surface of mounting hole 101. The extension 2022 adheres to the inner wall of mounting hole 101 and extends toward the inner wall of housing 1, further improving the stability of the connection between protective layer 202, explosion-proof valve 201, and housing 1.

[0054] In one embodiment, referring to FIG. 7 , a plurality of explosion-proof valve assemblies 2 are provided and are disposed on the same side wall of the housing 1 , and the protective layers 202 of the plurality of explosion-proof valve assemblies 2 are interconnected or integrally formed.

[0055] Such an arrangement can further improve the structural strength of the protective layer 202 and the connection strength between the protective layer 202 and the housing 1 and the explosion-proof valve 201 .

[0056] Specifically, when two or more explosion-proof valve assemblies 2 are provided, the protective layers 202 of adjacent explosion-proof valve assemblies 2 may be discontinuous or continuous. When the protective layers 202 of two or more adjacent explosion-proof valve assemblies 2 are continuous, the protective layers 202 may be integrally formed for ease of processing.

[0057] In one embodiment, the thickness of the protective layer 202 is 0.01 mm to 0.5 mm.

[0058] By controlling the thickness of the protective layer 202 within this range, the protective layer 202 can be easily formed and the waterproof performance of the protective layer 202 can be ensured while saving costs.

[0059] In one embodiment, referring to Figure 6, the explosion-proof valve 201 includes an explosion-proof valve body 2011 and a weak area 2012, the thickness of the weak area 2012 is smaller than the explosion-proof valve body 2011, the weak area 2012 is provided in the mounting hole 101, and the size of the mounting hole 101 is larger than the size of the weak area 2012.

[0060] With this arrangement, when the temperature rises and exceeds the set temperature and the protective layer 202 softens, the weak area 2012 becomes an effective pressure relief area of ​​the explosion-proof valve 201 and can fully contact the gas. The size of the mounting hole 101 is larger than the size of the weak area 2012 and will not limit the pressure relief area of ​​the weak area 2012.

[0061] In one embodiment, the weak area 2012 of the explosion-proof valve 201 is provided with notches, and the strength of the notches is significantly lower than that of the surrounding areas, which further facilitates the explosion and pressure relief of the explosion-proof valve 201 .

[0062] In one embodiment, the housing 1 includes two oppositely disposed first walls 102 and a second wall 103 connecting the two first walls 102 with a long side. The area of ​​the second wall 103 is smaller than that of the first wall 102 , and the explosion-proof valve assembly 2 is disposed on the second wall 103 .

[0063] Specifically, in this embodiment, the shell 1 is a rectangular parallelepiped structure with a cavity. Along the length direction of the shell 1, the two ends of the shell 1 are open and are respectively used to connect to the cover plate 3. The first wall 102 of the shell 1 is a large surface, consisting of a long side and a wide side. The second wall 103 is a side wall, and the second wall 103 and the first wall 102 are connected by the long side. The explosion-proof valve assembly 2 is arranged on the second wall 103. When an abnormality occurs inside the battery, causing heat and generating a large amount of gas, the gas moves along the width direction of the shell 1 to the explosion-proof valve assembly 2. Compared with the technical solution in which the explosion-proof valve assembly 2 is arranged on the cover plates 3 at both ends along the length direction of the shell 1, this arrangement has a shorter gas movement path, which is conducive to timely and rapid gas discharge and explosive pressure relief.

[0064] Specifically, referring to FIG. 3 , two second walls 103 are provided. When multiple explosion-proof valve assemblies 2 are provided, the multiple explosion-proof valve assemblies 2 may be provided on the same second wall 103 or may be separately provided on two second walls 103 .

[0065] In one embodiment, the set temperature is in the range of 50° C. to 200° C. Specifically, appropriate materials can be selected to make the protective layer 202 according to different set temperatures.

[0066] Specifically, in one embodiment, the set temperature is 50°C. When the battery temperature exceeds 50°C, protective layer 202 softens. At this point, even a small air pressure can rupture protective layer 202 without affecting the normal opening of explosion-proof valve 201. At room temperature, i.e., the normal operating temperature of the battery, protective layer 202 does not soften and can isolate the electrolyte from explosion-proof valve 201, protecting explosion-proof valve 201 from corrosion by the electrolyte.

[0067] In one embodiment, the set pressure is 0.2 MPa.

[0068] That is, when the temperature in the battery cavity is higher than the set temperature, the adhesion between the protective layer 202 and the explosion-proof valve 201 or the shell 1 almost disappears, and the protective layer 202 softens and its strength decreases. When the air pressure in the battery cavity is higher than 0.2 MPa, the protective layer 202 can be broken through, ensuring that the explosion-proof valve 201 can explode normally.

[0069] In one embodiment, the material of the protective layer 202 includes PE, PP, PET or glue. Optionally, the glue includes light-curing glue or thermosetting glue.

[0070] Specifically, the set temperature is determined according to the heat dissipation performance of different batteries and the temperature distribution when heat spreads from the batteries, and a suitable material is selected according to the set temperature to form the protective layer 202 .

[0071] The protective layer 202 can be formed by spraying, UV curing, or coating curing. Specifically, the protective layer 202 can be cured on the explosion-proof valve 201, and then welded to the housing 1. Alternatively, after the explosion-proof valve 201 is fixedly connected to the housing 1, the protective layer 202 can be applied to the inner wall of the explosion-proof valve 201, i.e., the end surface adjacent to the inner cavity of the housing 1. The protective layer 202 is required to completely cover at least the exposed area of ​​the explosion-proof valve 201.

[0072] In one embodiment, referring to FIG11 , an electrode group 4 is disposed within the housing 1 . The structure of the electrode group 4 matches that of the housing 1 . For a housing 1 having a rectangular parallelepiped structure, the electrode group 4 also has a rectangular parallelepiped structure. A side panel 5 is disposed between the side wall corresponding to the second wall 103 of the housing 1 and the side wall of the housing 1 . A heat dissipation channel 501 is provided on the side panel 5 at a position corresponding to the explosion-proof valve assembly 2 . The heat dissipation channel 501 is a through hole. The provision of the side panel 5 maintains a gap between the electrode group 4 and the second wall 103 of the housing 1 , facilitating the timely and rapid discharge of generated gas to the explosion-proof valve assembly 2 , thereby providing timely pressure relief and improving the safety performance of the battery.

[0073] In one embodiment, referring to FIG. 11 , the outer walls of the electrode group 4 and the side plate 5 are covered with an insulating film 6 to insulate the electrode group 4 from the housing 1 , and the side plate 5 from the housing 1 .

[0074] According to an embodiment of the present application, on the other hand, a battery pack is provided, comprising a plurality of batteries according to any one of the above technical solutions.

[0075] Since the battery pack includes batteries and has the same effect as the batteries, it will not be described in detail here.

[0076] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: A housing, wherein a mounting hole is provided on the housing; At least one explosion-proof valve assembly, the explosion-proof valve assembly comprising an explosion-proof valve and a protective layer, the explosion-proof valve is arranged in the mounting hole, and an end face of the explosion-proof valve close to the inner cavity of the shell has an exposed area exposed to the mounting hole, the protective layer is arranged on and covers the exposed area of ​​the explosion-proof valve to isolate the explosion-proof valve from the inner cavity of the shell, and the protective layer is suitable for softening when the temperature exceeds a set temperature so that the explosion-proof valve can open when the air pressure exceeds a set pressure.

2. The battery according to claim 1, characterized in that The protective layer comprises a protective layer body and extensions located on both sides of the protective layer body. The protective layer body is arranged on the end surface of the explosion-proof valve close to the inner cavity of the shell, and the extensions are at least attached to the inner wall of the mounting hole.

3. The battery according to claim 2, characterized in that A groove is provided at one end of the mounting hole away from the inner cavity of the shell, the explosion-proof valve is arranged in the groove, a step structure is formed between the exposed area and the end surface of the mounting hole, and the extension portion is attached to the inner wall of the mounting hole and extends toward the inner wall of the shell.

4. The battery according to any one of claims 1 to 3, characterized in that The explosion-proof valve components are provided in plurality and are arranged on the same side wall of the shell, and the protective layers of the plurality of explosion-proof valve components are interconnected or integrally formed.

5. The battery according to any one of claims 1 to 3, characterized in that The thickness of the protective layer is 0.01 mm to 0.5 mm.

6. The battery according to any one of claims 1 to 3, characterized in that The explosion-proof valve comprises an explosion-proof valve body and a weak area, the thickness of the weak area is smaller than that of the explosion-proof valve body, the weak area is arranged in the mounting hole, and the size of the mounting hole is larger than that of the weak area.

7. The battery according to any one of claims 1 to 3, characterized in that The shell includes two first walls arranged opposite to each other and a second wall connecting the two first walls with a long side, the area of ​​the second wall is smaller than that of the first wall, and the explosion-proof valve assembly is arranged on the second wall.

8. The battery according to any one of claims 1 to 3, characterized in that The set temperature is in the range of 50°C to 200°C; and / or the set pressure is 0.2Mpa.

9. The battery according to any one of claims 1 to 3, characterized in that The material of the protective layer includes PE, PP, PET or glue.

10. A battery pack, characterized in that: A battery comprising a plurality of batteries according to any one of claims 1 to 9.

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