battery

Abstract

The application relates to a battery, which comprises a shell, a battery cell, a cover plate assembly and a pressure relief assembly. The inside of the shell is provided with a containing cavity, at least one end of the shell is open, forming an open end; the cover plate assembly is sealed to the open end; the pressure relief assembly comprises a first heat conducting piece, a first sealing piece and a second heat conducting piece, the first heat conducting piece is provided with a pressure relief hole which is in communication with the outside of the shell, the first sealing piece is sealingly connected between the first heat conducting piece and the second heat conducting piece, the first sealing piece is used for forming a first pressure relief channel which is in communication with the pressure relief hole between the first heat conducting piece and the second heat conducting piece when being heated and melted; at least one of the cover plate assembly and the shell is provided with a first through hole which is in communication with the containing cavity, at least part of the pressure relief assembly is arranged in the first through hole, the first heat conducting piece is sealingly connected with the hole side wall of the first through hole, and the first sealing piece and the second heat conducting piece are both located on the side of the first heat conducting piece which faces the battery cell. The battery can be quickly pressure relieved, and the safety performance is good.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a battery. Background Technology

[0002] Lithium-ion batteries, as core energy storage devices in the new energy field, are widely used in electric vehicles and other areas. In recent years, the rapid development of large-cell technologies such as 4680 cylindrical batteries and blade batteries has significantly increased the capacity of individual battery cells, but it has also led to a doubling of the internal gas pressure of the battery, placing higher demands on the battery's sealing performance and pressure relief capabilities.

[0003] The lithium-ion batteries in the relevant technologies have the following shortcomings: the explosion-proof valve of the battery relies on pressure to trigger the explosion, which leads to a delay in the pressure relief of the battery, resulting in poor battery safety performance. Utility Model Content

[0004] Therefore, it is necessary to provide a battery that can quickly release pressure and has good safety performance to address the above problems.

[0005] A battery is provided, comprising:

[0006] The housing has an internal cavity, and at least one end of the housing has an opening communicating with the cavity, forming an open end;

[0007] The battery cell is disposed in the receiving cavity;

[0008] Cover assembly, the cover assembly sealing the opening end; and

[0009] The pressure relief assembly includes a first heat-conducting element, a first sealing element, and a second heat-conducting element. The first heat-conducting element is provided with a pressure relief hole communicating with the outside of the housing. The first sealing element is sealed between the first heat-conducting element and the second heat-conducting element. The first sealing element is used to form a first pressure relief channel communicating with the pressure relief hole between the first heat-conducting element and the second heat-conducting element when heated and melted.

[0010] In this embodiment, at least one of the cover plate assembly and the housing is provided with a first through hole communicating with the receiving cavity, at least a portion of the pressure relief assembly is disposed in the first through hole, and the first thermal conductive element is sealed to the sidewall of the first through hole, and the first sealing element and the second thermal conductive element are both located on the side of the first thermal conductive element facing the battery cell.

[0011] In one embodiment, the second heat-conducting element includes a substrate and a boss connected to the substrate. The boss protrudes from one side of the substrate. The first sealing element is provided with a second through hole, which communicates with the first through hole. The first sealing element is sealed between the first heat-conducting element and the substrate. The end of the boss away from the substrate passes through the second through hole and the first through hole in sequence.

[0012] In one embodiment, the first through hole includes a first hole and a second hole, the first hole and the second hole being distributed sequentially from the receiving cavity toward the outside of the housing, the radial dimension of the first hole being smaller than the radial dimension of the second hole, a step being formed between the first hole and the second hole, the second heat-conducting element being disposed on the side of the step facing away from the receiving cavity, and the substrate abutting against the step, the first heat-conducting element being sealed to the sidewall of the second hole.

[0013] In one embodiment, the first heat-conducting element is made of metal;

[0014] And / or, the material of the second heat-conducting element is metal.

[0015] In one embodiment, the heat-melting temperature of the first seal is 90°C-125°C.

[0016] In one embodiment, the cover plate assembly includes a substrate, an electrode post, and a second sealing member. The substrate is sealed to the opening end and has a third through hole. The electrode post includes an electrode post body and a protrusion plate surrounding the outer periphery of the electrode post body and connected to the electrode post body. The electrode post body is electrically connected to the negative or positive tab of the battery cell. The protrusion plate is located on the side of the substrate facing the receiving cavity. The second sealing member is sealed between the substrate and the protrusion plate. The second sealing member has a fourth through hole communicating with the third through hole. One end of the electrode post passes through the fourth through hole and the third through hole in sequence and protrudes from the side of the substrate facing away from the receiving cavity. The second sealing member is used to form a second pressure relief channel communicating with the third through hole between the protrusion plate and the substrate when heated and melted. The hot melt temperature of the second sealing member is greater than the hot melt temperature of the first sealing member.

[0017] In one embodiment, the substrate is provided with the first through hole, and the first through hole and the third through hole are distributed at intervals.

[0018] In one embodiment, the heat-melting temperature of the second seal is 160°C-230°C.

[0019] In one embodiment, the cover plate assembly further includes a fixing member disposed on the side of the substrate facing away from the receiving cavity, the fixing member being connected to the substrate and the pole body respectively.

[0020] In one embodiment, the cover plate assembly further includes an insulating frame disposed on the side of the substrate facing the receiving cavity and connected to the substrate. The pole body has a first end and a second end opposite to each other. The first end passes through the fourth through hole and the third through hole in sequence and protrudes from the side of the substrate facing away from the receiving cavity. The second end passes through the insulating frame and is electrically connected to the positive or negative electrode tab.

[0021] In the aforementioned battery, at least one of the cover plate assembly and the housing has a first through hole. During battery manufacturing, electrolyte can be injected into the receiving cavity through the first through hole. After the electrolyte injection is completed, the first through hole is sealed by a pressure relief assembly. Since the first thermally conductive element is sealed to the sidewall of the first through hole, and the first sealing element is sealed between the first thermally conductive element and the second thermally conductive element, the pressure relief assembly blocks the first through hole during normal battery use, preventing electrolyte leakage from the housing through the first through hole. Understandably, when a battery experiences thermal runaway and a large amount of high-temperature gas is generated inside the casing, both the first and second thermal conductive elements have thermal conductivity. The high temperature inside the casing will act on the first seal through the first and second thermal conductive elements, causing the temperature of the first seal to rise. Since the first seal can be melted by heat, when the temperature of the first seal reaches the melting temperature, the first seal melts, causing the first thermal conductive element to separate from the second thermal conductive element at least partially. This forms a first pressure relief channel between the first and second thermal conductive elements, which communicates with the pressure relief hole on the first thermal conductive element. In this way, the high-temperature gas inside the casing can be discharged to the outside of the casing through the first pressure relief channel and the pressure relief hole in sequence, thereby achieving battery pressure relief. Attached Figure Description

[0022] Figure 1 This is a perspective view of the battery described in some embodiments of this application.

[0023] Figure 2 This is a cross-sectional view of a battery (cell not shown) according to some embodiments of this application.

[0024] Figure 3 This is a cross-sectional view of the cover plate assembly and pressure relief assembly described in some embodiments of this application.

[0025] Figure 4 for Figure 3 A magnified view of a portion of point A in the middle.

[0026] Figure 5 for Figure 3 A magnified view of a section at point B in the middle.

[0027] Figure 6 This is an exploded view of the pressure relief assembly described in some embodiments of this application.

[0028] Figure 7 This is an exploded view of the pressure relief assembly and cover plate assembly in some embodiments of this application.

[0029] In the figure: 1. Housing; 2. Cover plate assembly; 21. Base plate; 211. First through hole; 211a. First hole; 211b. Second hole; 212. Step; 213. Third through hole; 22. Pole post; 221. Pole post body; 222. Protrusion plate; 23. Fixing member; 24. Insulating frame; 25. Busbar; 26. Second sealing member; 261. Fourth through hole; 3. Pressure relief assembly; 31. First heat conduction member; 311. Pressure relief hole; 32. Second heat conduction member; 321. Base; 322. Boss; 33. First sealing member; 331. Second through hole; 100. Receiving cavity. Detailed Implementation

[0030] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0031] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0035] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0036] See Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 6 , Figure 1 A perspective view of a battery according to an embodiment of this application is shown; Figure 2 A cross-sectional view of a battery (cell not shown) is shown in some embodiments of this application. Figure 3 Cross-sectional views of the cover plate assembly and pressure relief assembly described in some embodiments of this application are shown; Figure 4 It shows Figure 3 A magnified view of a section at point A in the middle; Figure 6An exploded view of the pressure relief assembly described in some embodiments of this application is shown. One embodiment of this application provides a battery including a housing 1, a battery cell, a cover assembly 2, and a pressure relief assembly 3. The housing 1 has an internal receiving cavity 100, and at least one end of the housing 1 has an opening communicating with the receiving cavity 100, forming an open end. The battery cell is disposed in the receiving cavity 100. The cover assembly 2 seals the open end of the housing 1. The pressure relief assembly 3 includes a first heat-conducting element 31, a first sealing element 33, and a second heat-conducting element 32. The first heat-conducting element 31 has a pressure relief hole 311 communicating with the outside of the housing 1. The first sealing element 33 is sealed between the first heat-conducting element 31 and the second heat-conducting element 32. The first sealing element 33 is used to form a first pressure relief channel communicating with the pressure relief hole 311 between the first heat-conducting element 31 and the second heat-conducting element 32 when heated and melted. In this embodiment, at least one of the cover plate assembly 2 and the housing 1 is provided with a first through hole 211 communicating with the receiving cavity 100, at least a portion of the pressure relief assembly 3 is provided in the first through hole 211, and the first heat-conducting element 31 is sealed to the side wall of the first through hole 211, and the first sealing element 33 and the second heat-conducting element 32 are both located on the side of the first heat-conducting element 31 facing the battery cell.

[0037] At least one of the cover plate assembly 2 and the housing 1 is provided with a first through hole 211. During battery manufacturing, electrolyte can be injected into the receiving cavity 100 through the first through hole 211. After the electrolyte injection is completed, the first through hole 211 is sealed by the pressure relief assembly 3. Since the first heat-conducting element 31 is sealed to the sidewall of the first through hole 211, and the first sealing element 33 is sealed between the first heat-conducting element 31 and the second heat-conducting element 32, the pressure relief assembly 3 blocks the first through hole 211 during normal battery use, preventing electrolyte inside the housing 1 from leaking out through the first through hole 211. It is understood that when the battery experiences thermal runaway and a large amount of high-temperature gas is generated inside the housing 1, both the first heat-conducting element 31 and the second heat-conducting element 32 have thermal conductivity. The high temperature inside the housing 1 will act on the first sealing element 33 through the first heat-conducting element 31 and the second heat-conducting element 32, causing the temperature of the first sealing element 33 to rise. The first sealing element 33 can be heated and melted. When the temperature of the first sealing element 33 reaches the melting temperature, the first sealing element 33 melts and causes the first heat-conducting element 31 to be at least partially separated from the second heat-conducting element 32, thereby forming a first pressure relief channel between the first heat-conducting element 31 and the second heat-conducting element 32, which communicates with the pressure relief hole 311 on the first heat-conducting element 31. In this way, the high-temperature gas inside the housing 1 can be discharged to the outside of the housing 1 through the first pressure relief channel and the pressure relief hole 311 in sequence, thereby realizing the pressure relief of the battery.

[0038] Traditional batteries typically employ a mechanical membrane pressure relief structure formed by grooves on the cover assembly 2. Pressure relief is achieved by the high-pressure gas inside the casing 1 breaking through the grooves on the cover assembly 2. However, in the event of battery thermal runaway, manufacturing precision errors in the grooves can lead to delayed pressure relief, resulting in a higher risk of battery explosion due to the inability to quickly relieve pressure. In the battery of this application, during battery thermal runaway, the high temperature inside the casing 1 acts on the first sealing element 33 through the first heat-conducting element 31 and the second heat-conducting element 32, causing the first sealing element 33 to melt and form a first pressure relief channel between the first heat-conducting element 31 and the second heat-conducting element 32, which communicates with the pressure relief hole 311. The pressure relief response precedes the mechanical membrane pressure relief structure, enabling rapid discharge of high-temperature gas inside the casing 1, increasing the battery's pressure relief speed, thereby improving battery safety performance and reducing the risk of battery explosion due to untimely pressure relief. In addition, since the first sealing element 33 and the second heat-conducting element 32 are both located on the side of the first heat-conducting element 31 facing the battery cell, and the first heat-conducting element 31 is provided with a pressure relief hole 311 communicating with the outside of the housing 1, when the first sealing element 33 is heated and melted, the high-temperature gas inside the housing 1 can be quickly discharged to the outside of the battery through the first pressure relief channel from the pressure relief hole 311, ensuring the pressure relief speed of the battery.

[0039] Combination Figure 6 The second heat-conducting element 32 includes a base 321 and a boss 322 connected to the base 321. The boss 322 protrudes from one side of the base 321. The first sealing element 33 is provided with a second through hole 331, which communicates with the first through hole 211. The first sealing element 33 is sealed between the first heat-conducting element 31 and the base 321. The end of the boss 322 away from the base 321 has the second through hole 331 and the first through hole 211 passing through it in sequence. With this structure, the boss 322 can be used to position the first sealing element 33 and the cover plate assembly 2 when assembling the pressure relief assembly 3 and the cover plate assembly 2, which is beneficial for battery assembly.

[0040] Combination Figure 7The first through hole 211 includes a first hole 211a and a second hole 211b, which are sequentially distributed from the receiving cavity 100 toward the outside of the housing 1. Both the first hole 211a and the second hole 211b are circular holes. The radial dimension of the first hole 211a is smaller than that of the second hole 211b. A step 212 is formed between the first hole 211a and the second hole 211b. The second heat-conducting element 32 is disposed on the side of the step 212 facing away from the receiving cavity 100, and the base 321 abuts against the step 212. The first heat-conducting element 31 is sealed to the sidewall of the second hole 211b. The centerline of the first hole 211a coincides with the centerline of the second hole 211b. Since the radial dimension of the first hole 211a is smaller than that of the second hole 211b, a step 212 is formed between the first hole 211a and the second hole 211b. Thus, when the pressure relief assembly 3 is installed in the first through hole 211, the base 321 of the second heat conductor 32 can be placed on the step 212, so that the base 321 abuts against the step 212. The step 212 supports the pressure relief assembly 3, so as to facilitate the tight connection between the first heat conductor 31 and the sidewall of the second hole 211b, reducing the installation difficulty of the pressure relief assembly 3.

[0041] In one example, the first heat-conducting element 31 is a metallic body, which can be made of aluminum, nickel, or stainless steel alloy, etc. When the first heat-conducting element 31 is metallic, it is laser-welded to the sidewall of the second hole 211b to achieve a sealed connection. Of course, in other examples, the first heat-conducting element 31 can also be a non-metallic body. In this case, it is bonded to the sidewall of the second hole 211b using an adhesive layer to achieve a sealed connection. Therefore, there are no specific limitations on the material of the first heat-conducting element 31.

[0042] As an example, the second heat-conducting element 32 is a metallic body, such as an aluminum, nickel, or stainless steel alloy. Of course, in actual implementation, the material of the second heat-conducting element 32 can be flexibly selected as needed. There are no specific restrictions on the material of the second heat-conducting element 32. For example, the second heat-conducting element 32 can be set as a non-metallic body.

[0043] The thickness of the first heat-conducting element 31 is 0.1mm-0.5mm, and the thickness of the second heat-conducting element 32 is 0.1mm-0.5mm. By setting the thicknesses of the first heat-conducting element 31 and the second heat-conducting element 32 within this range, the manufacturing materials of the battery can be saved as much as possible while ensuring the structural strength of the first heat-conducting element 31 and the second heat-conducting element 32.

[0044] The heat-melting temperature of the first sealing element 33 is 90℃-125℃. The thickness of the first sealing element 33 is 0.05mm-0.2mm. In actual implementation, the heat-melting temperature of the first sealing element 33 can be set to 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, or 125℃, etc. Setting the heat-melting temperature of the first sealing element 33 within the above range ensures that when the internal temperature of the casing 1 rises due to thermal runaway of the battery, the first sealing element 33 can melt in time, allowing the first heat-conducting element 31 to separate from the second heat-conducting element 32 and forming a first pressure relief channel between the first heat-conducting element 31 and the second heat-conducting element 32. This allows for pressure relief before the mechanical membrane pressure relief structure, improving the battery's safety performance and reducing the risk of battery explosion.

[0045] In some embodiments, see Figure 3 , Figure 5 and Figure 7 The cover plate assembly 2 also includes a substrate 21, an electrode post 22, and a second sealing element 26. In this example, a first through hole 211 is provided on the substrate 21. The substrate 21 is sealed at the open end and is provided with a third through hole 213. The substrate 21 is an aluminum alloy plate or a nickel-plated steel plate, and the thickness of the substrate 21 is set to 1mm-2.5mm to ensure the structural strength of the substrate 21. The electrode post 22 is made of conductive materials such as aluminum, copper, aluminum alloy, copper alloy, or stainless steel. When the electrode post 22 is a positive electrode post, the electrode post 22 is an aluminum or stainless steel part; when the electrode post 22 is a negative electrode post, the electrode post 22 is a copper part, a copper-aluminum composite part, or a nickel-plated stainless steel part. The electrode post 22 includes an electrode post body 221 and a protruding plate 222 surrounding the outer periphery of the electrode post body 221 and connected to the electrode post body 221. The electrode body 221 is electrically connected to the negative or positive tab of the battery cell. The protrusion 222 is located on the side of the substrate 21 facing the receiving cavity 100. The second sealing member 26 is sealed between the substrate 21 and the protrusion 222. The second sealing member 26 is provided with a fourth through hole 261 communicating with the third through hole 213. One end of the electrode 22 passes through the fourth through hole 261 and the third through hole 213 in sequence and protrudes from the side of the substrate 21 facing away from the receiving cavity 100. When heated and melted, the second sealing member 26 forms a second pressure relief channel communicating with the third through hole 213 between the protrusion 222 and the substrate 21. The heat melting temperature of the second sealing member 26 is greater than the heat melting temperature of the first sealing member 33.

[0046] The opening of the third through hole 213 provides space for the lead-out of the electrode body 221, so as to facilitate the connection of external electrical equipment with the battery. When the battery is in normal condition, the second seal 26 seals between the protrusion 222 and the substrate 21, and the electrolyte and gas inside the housing 1 cannot leak to the outside of the housing 1 from the third through hole 213 and the fourth through hole 261. Since the melting temperature of the second seal 26 is greater than that of the first seal 33, when the battery experiences thermal runaway, the first seal 33 melts first, forming a first pressure relief channel between the first heat-conducting element 31 and the second heat-conducting element 32, which communicates with the pressure relief hole 311. If the battery thermal runaway cannot be effectively controlled, high-temperature gas continues to be generated inside the casing 1, and the temperature inside the casing 1 continues to rise. The high temperature of the casing 1 is conducted to the second seal 26 through the protrusion 222 and the electrode body 221. When the temperature of the second seal 26 reaches the melting temperature, the second seal 26 melts, causing the protrusion 222 to peel off from the substrate 21. This forms a second pressure relief channel between the protrusion 222 and the substrate 21, which communicates with the third through hole 213. Thus, the high-temperature gas inside the casing 1 can be discharged to the outside of the casing 1 through the second pressure relief channel and the third through hole 213 in sequence, allowing the third through hole 213 to also relieve pressure on the battery, further improving the battery's safety performance. In the event of accidental blockage of the pressure relief hole 311, the high temperature inside the casing 1 can melt the second seal 26, allowing the high-temperature gas inside the casing 1 to be discharged to the outside of the casing 1 through the second pressure relief channel and the third through hole 213, ensuring battery safety. Furthermore, during battery use, both the boss 322 and the terminal body 221 carry current, which heats up. The second seal 26 is designed to have a higher melting temperature than the first seal 33 to prevent it from melting under heat during normal battery use. Unlike conventional batteries, in this application, the second seal 26 is sealed between the substrate 21 and the boss 222, simplifying the sealing structure and improving the sealing reliability between the terminal 22 and the substrate 21.

[0047] In one example, the third through hole 213 is a circular hole with a diameter greater than 4.0 mm to allow sufficient space to pass through the pole body 221.

[0048] In this example, the fourth through hole 261 is provided in the middle of the second seal 26, so that the second seal 26 has an annular structure.

[0049] In one example, the battery is a cylindrical battery. For this type of battery, the opening end of the casing 1 is circular. To make the shape of the substrate 21 match the shape of the opening end, the substrate 21 is a disc. Of course, in other examples, the shape of the substrate 21 can be flexibly adjusted according to the shape of the opening end of the casing 1. Here, no specific limitation is made on the shape of the substrate 21.

[0050] The second sealing element 26 is thermally bonded to the substrate 21 and the protruding plate 222 respectively, so that the second sealing element 26 is sealed between the substrate 21 and the protruding plate 222. In actual implementation, the bonding method between the second sealing element 26 and the substrate 21 and the protruding plate 222 can be flexibly selected as needed, such as high-temperature bonding or bonding with an electrolyte-resistant acrylic adhesive.

[0051] The heat fusion temperature of the second seal 26 is 160℃-230℃. In actual implementation, the temperature of the second seal 26 can be set to 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃ or 230℃, etc.

[0052] The second seal 26 includes, but is not limited to, electrolyte-resistant hot melt adhesive, modified acrylic adhesive, modified epoxy resin adhesive, or modified polyurethane adhesive.

[0053] In one example, the substrate 21 is provided with a first through hole 211, and the first through hole 211 and the third through hole 213 are distributed at intervals. In this way, the first through hole 211 and the second through hole 331 are integrated on the substrate 21, which facilitates the opening of the first through hole 211 and the second through hole 331.

[0054] In other examples, a first through hole 211 may also be provided on the housing 1. Alternatively, if a first through hole 211 is provided on the substrate 21, a first through hole 211 may also be provided on the housing 1. For example, a first through hole 211 may be provided on the side wall or bottom of the housing 1. Each first through hole 211 corresponds to a set of pressure relief components 3. In this way, the battery can be depressurized on both the cover plate assembly 2 and the housing 1 at the same time.

[0055] It is understandable that batteries may be subjected to vibration during transportation or in certain applications. To ensure the battery can function properly in vibrating environments, the cover assembly 2 also includes a fixing member 23. The fixing member 23 is located on the side of the substrate 21 facing away from the receiving cavity 100, and is connected to both the substrate 21 and the electrode body 221. The fixing member 23 includes at least one of the following: ABS plastic (acrylonitrile-butadiene-styrene copolymer), PC plastic (polycarbonate), PA plastic (nylon, polyamide), PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), epoxy resin, UV adhesive, PEEK (polyetheretherketone), LCP (liquid crystal polymer), and PEI (polyetherimide). The connection of the fixing member 23 to the substrate 21 and the electrode body 221 also ensures a stable structure for the battery in high-temperature environments, improving the battery's high-temperature resistance.

[0056] In this example, the fixing member 23 is annular and surrounds the periphery of the terminal body 221. In actual implementation, in order to allow the battery to release pressure at the third through hole 213 during thermal runaway, the fixing member 23 and the terminal body 221 can be connected in a discontinuous manner. This allows for a space to be reserved between the sidewall of the third through hole 213 and the terminal body 221 for pressure release, preventing the fixing member 23 from completely blocking the gap between the terminal body 221 and the sidewall of the third through hole 213 and affecting pressure release. Alternatively, the fixing member 23 can be set as a thermosetting component. In this way, during battery thermal runaway, the heat inside the casing 1 is conducted to the fixing member 23 through the substrate 21 and the terminal body 221. After the temperature of the fixing member 23 reaches the thermosetting temperature, the fixing member 23 melts to prevent the fixing member 23 from blocking the gap between the terminal body 221 and the sidewall of the third through hole 213.

[0057] In some embodiments, see Figure 3 , Figure 4 , Figure 5 and Figure 7 The cover assembly 2 also includes an insulating frame 24, which is located on the side of the substrate 21 facing the receiving cavity 100 and connected to the substrate 21. In this example, the substrate 21, on the side facing the receiving cavity 100, has a recessed portion around the third through hole 213 for accommodating the second seal 26 and the protrusion 222. The pole body 221 has a first end and a second end opposite to each other. The first end passes through the fourth through hole 261 and the third through hole 213 in sequence and protrudes from the side of the substrate 21 facing away from the receiving cavity 100. The second end passes through the insulating frame 24 and is electrically connected to the positive or negative electrode ear. The insulating frame 24, connected to the side of the substrate 21 facing the receiving cavity 100, provides support to the substrate 21 and enhances the overall structural strength of the cover assembly 2.

[0058] In this example, the battery cell is a wound core, and the housing 1 has a structure with an open top and a sealed bottom. The cover assembly 2 also includes a busbar 25, which is welded to the negative electrode tab at the upper end of the battery cell and bent, and installed on the side of the insulating frame 24 facing the receiving cavity 100. The positive electrode tab at the lower end of the battery cell is welded to the bottom of the housing 1. It is not necessary to add a busbar 25 to the bottom of the housing 1, thus saving on battery structural components. The housing 1 is formed by stamping aluminum material, and the substrate 21 is sealed to the open end of the housing 1 by laser welding. The bottom of the housing 1 is stamped with an explosion-proof structure, such as explosion-proof grooves. In this way, the explosion-proof structure can be used as a backup pressure relief valve. If both the first and second pressure relief channels fail, pressure can be relieved through the explosion-proof structure at the bottom of the housing 1, further improving the safety performance of the battery.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery, characterized in that, include: The housing has an internal cavity, and at least one end of the housing has an opening communicating with the cavity, forming an open end; The battery cell is disposed in the receiving cavity; A cover assembly that seals the opening end; and The pressure relief assembly includes a first heat-conducting element, a first sealing element, and a second heat-conducting element. The first heat-conducting element is provided with a pressure relief hole communicating with the outside of the housing. The first sealing element is sealed between the first heat-conducting element and the second heat-conducting element. The first sealing element is used to form a first pressure relief channel communicating with the pressure relief hole between the first heat-conducting element and the second heat-conducting element when heated and melted. In this embodiment, at least one of the cover plate assembly and the housing is provided with a first through hole communicating with the receiving cavity, at least a portion of the pressure relief assembly is disposed in the first through hole, and the first thermal conductive element is sealed to the sidewall of the first through hole, and the first sealing element and the second thermal conductive element are both located on the side of the first thermal conductive element facing the battery cell.

2. The battery according to claim 1, characterized in that, The second heat-conducting component includes a base and a boss connected to the base. The boss protrudes from one side of the base. The first sealing component is provided with a second through hole, which communicates with the first through hole. The first sealing component is sealed between the first heat-conducting component and the base. The end of the boss away from the base passes through the second through hole and the first through hole in sequence.

3. The battery according to claim 2, characterized in that, The first through hole includes a first hole and a second hole, which are distributed sequentially from the receiving cavity toward the outside of the housing. The radial dimension of the first hole is smaller than the radial dimension of the second hole. A step is formed between the first hole and the second hole. The second heat-conducting element is disposed on the side of the step facing away from the receiving cavity, and the substrate abuts against the step. The first heat-conducting element is sealed to the sidewall of the second hole.

4. The battery according to any one of claims 1 to 3, characterized in that, The first heat-conducting component is made of metal; And / or, the material of the second heat-conducting element is metal.

5. The battery according to any one of claims 1 to 3, characterized in that, The heat-melting temperature of the first seal is 90℃-125℃.

6. The battery according to claim 1, characterized in that, The cover plate assembly includes a substrate, an electrode post, and a second sealing member. The substrate is sealed to the opening end and has a third through hole. The electrode post includes an electrode post body and a protrusion plate surrounding the outer periphery of the electrode post body and connected to the electrode post body. The electrode post body is electrically connected to the negative or positive electrode tab of the battery cell. The protrusion plate is located on the side of the substrate facing the receiving cavity. The second sealing member is sealed between the substrate and the protrusion plate. The second sealing member has a fourth through hole communicating with the third through hole. One end of the electrode post passes through the fourth through hole and the third through hole in sequence and protrudes from the side of the substrate facing away from the receiving cavity. The second sealing member is used to form a second pressure relief channel communicating with the third through hole between the protrusion plate and the substrate when heated and melted. The hot melt temperature of the second sealing member is greater than the hot melt temperature of the first sealing member.

7. The battery according to claim 6, characterized in that, The substrate is provided with the first through hole, and the first through hole and the third through hole are distributed at intervals.

8. The battery according to claim 6, characterized in that, The heat-melting temperature of the second seal is 160℃-230℃.

9. The battery according to claim 6, characterized in that, The cover plate assembly further includes a fixing member disposed on the side of the substrate facing away from the receiving cavity, the fixing member being connected to the substrate and the pole body respectively.

10. The battery according to claim 6, characterized in that, The cover plate assembly further includes an insulating frame disposed on the side of the substrate facing the receiving cavity and connected to the substrate. The pole body has a first end and a second end opposite to each other. The first end passes through the fourth through hole and the third through hole in sequence and protrudes from the side of the substrate facing away from the receiving cavity. The second end passes through the insulating frame and is electrically connected to the positive or negative electrode tab.

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