Secondary battery, battery assembly, and electronic device

Abstract

To provide a secondary battery, a battery assembly, and an electronic apparatus, capable of improving a phenomenon that, when an explosion prevention notch is broken, a construction component such as an electrode terminal and a collector member is deviated from a housing, and a short circuit or a thermal runaway is generated between secondary batteries in a battery module.SOLUTION: A secondary battery contains: a housing 10; an electrode terminal 20; an electrode assembly 40; and a collector member 50. The housing contains an end wall 101 and a side wall 11. The end wall contains a terminal hole 121 and an explosion prevention notch 122. A region surrounded by the explosion prevention notch on the end wall is an explosion prevention region 123. The electrode terminal is tightly fixed so as to be insulated by the end wall. The electrode assembly is arranged into the housing, and the side faced to the end wall of the electrode assembly contains a first electrode tub 41. The collector member contains a main body part 51 connected to the first electrode tub, and a terminal connection part 52 that is connected to the electrode terminal. The main body part contains a deformation variable part 511 that is adopted so as to maintain a connection between the electrode terminal and the main body part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to the field of battery technology, and in particular to secondary batteries, battery assemblies, and electronic devices. [Background technology]

[0002] In the prior art, to ensure normal pressure relief of secondary batteries and reduce the risk of battery explosion, explosion-proof structures typically include explosion-proof notches on the housing. When the pressure inside the housing exceeds a threshold, the explosion-proof notches break, allowing the secondary battery to release pressure. Existing secondary battery structures typically have explosion-proof notches and electrode terminals at both ends of the secondary battery in the height direction, occupying both ends of the secondary battery and rendering them unusable as cooling surfaces. After assembling secondary battery assemblies into battery modules, the only way to cool the battery modules is to place a cooling plate between the side surfaces of adjacent secondary batteries. This cooling method increases the lateral space of the battery module, which is not advantageous for improving the energy density of the battery module.

[0003] However, if the explosion-proof notch and the electrode terminal are arranged on the same side of the secondary battery, there is a risk that the electrode terminal and current collecting member in the explosion-proof area will fly out of the housing when the explosion-proof notch breaks, which could cause serious problems such as short circuits and thermal runaway between other secondary batteries in the battery module, thereby increasing safety risks at the battery module level. Summary of the Invention [Problem to be solved by the invention]

[0004] In consideration of the above-mentioned drawbacks of the prior art, the present invention provides a secondary battery, a battery assembly, and an electronic device that can improve the phenomenon in which structural components such as electrode terminals and current collecting members fly out of the casing when the anti-explosion notch is ruptured, causing technical problems such as short circuits and thermal runaway among other secondary batteries in a battery module. [Means for solving the problem]

[0005] To achieve the above and other related objectives, the present invention provides a secondary battery including a housing, an electrode terminal, an electrode assembly, and a current collecting member. The housing includes an end wall and a side wall surrounding the end wall. The end wall includes a terminal hole and an explosion-proof notch surrounding the terminal hole. The area on the end wall surrounded by the explosion-proof notch is an explosion-proof area. The electrode terminal covers the terminal hole and is fixed to the end wall, and an insulating sealing member is disposed between the electrode terminal and the end wall. The electrode assembly is disposed within the housing, and a side of the electrode assembly facing the end wall includes a first electrode tab. The current collecting member is disposed within the housing and is located between the first electrode tab and the electrode terminal. The current collecting member includes a main body portion and a terminal connection portion, and the main body portion is connected to the first electrode tab. The terminal connection portion is connected to an inner surface of the electrode terminal facing the electrode assembly. The main body portion includes a deformable portion connected to the terminal connection portion. When the internal pressure of the housing exceeds a threshold value, the explosion-proof notch ruptures, the explosion-proof region at least partially separates from the housing, moving away from the electrode assembly with the electrode terminal, and the deformable portion deforms to maintain the connection between the electrode terminal and the main body portion.

[0006] In one example of the secondary battery of the present invention, the terminal connection portion is disposed in the central region of the main body portion, and the deformable portion includes a first curved structure surrounding the terminal connection portion.

[0007] In one example of the secondary battery of the present invention, the first curved structure includes a first recess and a first protrusion, the first recess is recessed from one side of the main body portion toward another side of the main body portion, and the first protrusion is correspondingly formed on the other side of the main body portion, and the first protrusion is arranged in a ring shape and surrounds the outer periphery of the terminal connection portion.

[0008] In one example of the secondary battery of the present invention, the first protrusion is arranged on the side of the main body facing the end wall, and the first recess is arranged on the side of the main body facing the electrode assembly.

[0009] In one example of the secondary battery of the present invention, the width of the primary projections along the radial direction of the secondary battery is 2 mm to 10 mm, and the height of the primary projections along the axial direction of the secondary battery is 1 mm to 5 mm.

[0010] In one example of the secondary battery of the present invention, the primary projections are formed in an annular shape, and the outer diameter of the primary projections is 38 mm or less.

[0011] In one example of the secondary battery of the present invention, the welding connection strength between the electrode terminal and the terminal connection portion is greater than 50N.

[0012] In one example of the secondary battery of the present invention, a thinned area is arranged in the electrode terminal along the thickness direction, and the terminal connection portion and the thinned area abut against each other and are connected by welding.

[0013] In one example of the secondary battery of the present invention, the electrode terminal has a second recess arranged on the side facing the electrode assembly, and the terminal connection portion has a second protrusion arranged on the side facing the electrode terminal, and the second protrusion and the second recess abut against each other and are connected by welding.

[0014] In one example of the secondary battery of the present invention, the terminal connection portion and the main body portion are configured separately, and the thickness of the terminal connection portion is greater than the thickness of the main body portion.

[0015] In one example of the secondary battery of the present invention, the terminal connection portion and the main body portion are connected by welding, and the welding connection strength is greater than 50N.

[0016] In one example of the secondary battery of the present invention, a weld mark is formed between the terminal connection portion and the main body portion, the weld mark has a ring structure, and the weld mark has at least two turns.

[0017] In one example of the secondary battery of the present invention, the main body portion includes a support portion arranged in an annular shape, the terminal connection portion is located within a central region of the support portion, the deformable portion includes a weak portion extending from the support portion toward the terminal connection portion, and the terminal connection portion is connected to the main body portion via the weak portion.

[0018] In one example of the secondary battery of the present invention, the weakened portion includes a bend-guiding portion that guides the weakened portion so that the weakened portion bends.

[0019] In one example of the secondary battery of the present invention, the bending guide portion includes a second curved portion, and the second curved portion is disposed on a side of the weakened portion closer to the support portion.

[0020] In one example of the secondary battery of the present invention, the bending guide portion includes a crease, and the crease is disposed on a side of the weakened portion closer to the support portion.

[0021] In one example of the secondary battery of the present invention, the main body further includes a plurality of electrode tab connection portions, the plurality of electrode tab connection portions extending from the support portion toward the center of the electrode assembly, and the plurality of electrode tab connection portions being spaced apart from the terminal connection portion.

[0022] In one example of the secondary battery of the present invention, the orthogonal projection of the support portion is located outside the orthogonal projection of the explosion-proof area along the height direction of the secondary battery and does not overlap with the orthogonal projection of the explosion-proof area.

[0023] The present invention also provides a battery assembly including a secondary battery.

[0024] The present invention further provides an electronic device including a battery assembly. [Effects of the Invention]

[0025] In the secondary battery according to the present invention, both the explosion-proof notch and the electrode terminal are located on the end wall of the housing. This allows for a same-side arrangement between the explosion-proof notch and the electrode terminal, allowing the electrical connection between battery module levels and the thermal runaway system to be installed on the same side of the battery module. This allows the cooling system to be located on another side of the battery module, reducing the lateral dimension of the battery module, which is advantageous for improving the energy density of the battery module. At the same time, in the secondary battery according to the present invention, the deformable portion is located on the main body of the current collecting member. When the explosion-proof region separates from the housing, the deformable portion deforms to maintain the connection between the electrode terminal and the main body, preventing the explosion-proof region on the end wall and the electrode terminal from jumping out of the housing. This avoids serious problems such as short circuits and thermal runaway between other secondary batteries, improving the safety performance of the battery module. [Brief explanation of the drawings]

[0026] In order to more clearly describe the embodiments of the present invention or the technical solutions of the prior art, the drawings that need to be used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. Those skilled in the art can obtain other drawings based on these drawings without any creative efforts.

[0027] [Figure 1] 1 is a main view of a secondary battery according to one embodiment of the present invention. [Figure 2] 1 is an axial side view of a secondary battery according to an embodiment of the present invention. [Figure 3] FIG. 2 is a partial cross-sectional view taken along the direction AA in FIG. [Figure 4] 1 is a partially enlarged view of attachment positions of electrode terminals and current collecting members of a secondary battery according to one embodiment of the present invention. [Figure 5]FIG. 2 is a schematic exploded view of the attachment positions of the current collecting members and electrode assemblies of a secondary battery according to one embodiment of the present invention. [Figure 6] 1 is an axial side view of the overall structure of a current collecting member of a secondary battery according to one embodiment of the present invention. [Figure 7] 1 is a top view of a current collecting member of a secondary battery according to one embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view taken along the direction BB in FIG. 7. [Figure 9] FIG. 3 is a schematic distribution diagram of primary protrusions on a main body of a secondary battery according to an embodiment of the present invention. [Figure 10] FIG. 2 is a schematic structural diagram of a secondary protrusion of a secondary battery according to an embodiment of the present invention. [Figure 11] FIG. 4 is a partial structural cross-sectional view of a secondary battery according to another embodiment of the present invention. [Figure 12] FIG. 10 is a schematic exploded view of the attachment positions of the current collecting members and electrode assemblies of a secondary battery according to another embodiment of the present invention. [Figure 13] FIG. 4 is an axial side view of the overall structure of a current collecting member of a secondary battery according to another embodiment of the present invention. [Figure 14] FIG. 4 is a top view of a current collecting member of a secondary battery according to another embodiment of the present invention. [Figure 15] FIG. 15 is a cross-sectional view taken along the CC direction in FIG. [Figure 16] FIG. 10 is a top view of a current collecting member of a secondary battery according to still another embodiment of the present invention. [Figure 17] FIG. 17 is a cross-sectional view taken along the DD direction of FIG. [Figure 18] 3 is a schematic diagram of an attachment position of a third insulating member of a secondary battery according to one embodiment of the present invention. FIG. [Figure 19] 2 is a schematic diagram of an insulating tape attachment position of a secondary battery according to one embodiment of the present invention. FIG. [Figure 20] 1 is a schematic exploded view of a first insulating member of a secondary battery according to an embodiment of the present invention; [Figure 21]1 is a cross-sectional view of the overall structure of a first insulating member of a secondary battery according to one embodiment of the present invention. [Figure 22] 1 is a schematic diagram of the overall structure of a battery assembly according to one embodiment of the present invention. [Figure 23] 1 is a schematic structural diagram of a battery assembly installed in a vehicle according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, the embodiments of the present invention will be described through specific examples. Those skilled in the art will understand other advantages and effects of the present invention from the contents disclosed herein. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can be variously modified and changed based on different perspectives and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless there is a contradiction. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments and do not limit the scope of the present invention. In the following examples, for test methods for which specific conditions are not specified, conventional conditions or conditions recommended by each manufacturer are usually adopted.

[0029] When an embodiment provides a numerical range, it should be understood that the two endpoints of each numerical range and any numerical value between the two endpoints can be selected unless otherwise specified in the present invention. Unless otherwise defined, all technical and scientific terms used in the present invention are consistent with the prior art knowledge and the description of the present invention by those skilled in the art. They can also be used with the methods described in the embodiments of the present invention. The devices and materials are similar or equivalent to any methods, devices, and materials in the prior art for implementing the present invention.

[0030] It should be noted that the terms "upper", "lower", "left", "right", "middle", "one" and the like used in this specification are merely for the convenience of description and are not used to limit the scope of the present invention. If there are changes or adjustments in relative relationships but no substantial changes in technical content, they should also be considered to be within the scope of the implementation mode of the present invention.

[0031] 1 to 23, the present invention provides a secondary battery 100, a battery assembly 200, and an electronic device 300. The secondary battery 100 can achieve a same-side arrangement between the explosion-proof notch 122 and the electrode terminal 20, thereby reducing the horizontal dimension occupied by the battery module, which is advantageous for improving the energy density of the battery module. In addition, by providing a deformable portion 511, the connection between the electrode terminal 20 and the main body 51 can be maintained when the explosion-proof region 123 is separated from the housing 10, thereby reducing the probability that the explosion-proof region 123 and the electrode terminal 20 will fly out of the housing 10 and improving safety at the battery module level.

[0032] 1 to 3, the structure of the secondary battery 100 will be further described. The secondary battery 100 includes a housing 10, an electrode terminal 20, an electrode assembly 40, and a current collecting member 50.

[0033] A cavity for accommodating the electrode assembly 40, electrolyte (not shown), and other components is formed within the housing 10. The cavity may be open at one end or both ends. Specifically, the size of the housing 10 can be determined based on the specific size of the electrode assembly 40, e.g., a diameter of 46 mm and a height of 80 mm, 95 mm, or 120 mm. The housing 10 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. A layer of an anti-corrosion material, such as metallic nickel, may be applied to the surface of the housing 10 to prevent the housing 10 from rusting during long-term use. In one embodiment of the secondary battery 100 of the present invention, the housing 10 includes a cylindrical side wall 11 and first and second end walls 101 and 102 that close both ends of the side wall 11. The first end wall 101 is integrally connected to one end of the side wall 11, and the second end wall 102 is hermetically connected to the other end of the side wall 11 by welding or mechanical external force. In another embodiment of the present invention, the first end wall 101 may be sealingly connected to one end of the side wall 11 by welding or external mechanical force, and the second end wall 102 may be integrally connected to the other end of the side wall 11. In other embodiments, the first end wall 101 and the second end wall 102 may each be sealingly connected to both ends of the side wall 11 by welding or external mechanical force.

[0034] The first end wall 101 includes a terminal hole 121 and an explosion-proof notch 122 surrounding the terminal hole 121. The area on the first end wall 101 surrounded by the explosion-proof notch 122 is an explosion-proof area 123. The explosion-proof area 123 may have a rectangular, circular, or other polygonal shape. In this embodiment, the explosion-proof area 123 has a circular shape. The explosion-proof notch 122 is located in a weak area of ​​the first end wall 101. When the air pressure inside the secondary battery 100 exceeds a threshold, the explosion-proof notch 122 ruptures, releasing the pressure inside the housing 10 and completing directional blasting of the secondary battery 100. The electrode terminal 20 covers the terminal hole 121 and is fixed to the first end wall 101. An insulating sealing member 30 is disposed between the electrode terminal 20 and the first end wall 101. The shape of the terminal hole 121 may be a round hole, a square hole, or other polygonal structure, as long as it satisfies the connection requirements of the electrode terminal 20 and secures the connection of the first end wall 101. The terminal hole 121 may be disposed in the central region of the first end wall 101 or in the outer circumferential region of the first end wall 101, as long as it corresponds to the installation position of the electrode terminal 20. In this embodiment, the terminal hole 121 has a round hole structure, and the terminal hole 121 and the explosion-proof region 123 are coaxially disposed on the first end wall 101.

[0035] There are many ways to securely connect the electrode terminal 20 to the first end wall 101. For example, the electrode terminal 20 may be riveted or glued to the first end wall 101, as long as the required strength of the connection between the electrode terminal 20 and the first end wall 101 is met. When securing the electrode terminal 20 to the first end wall 101, the electrode terminal 20 may extend through the terminal hole 121 into the housing 10, or may be positioned completely outside the first end wall 101 without passing through the terminal hole 121, as long as it is ensured that the electrode terminal 20 completely covers the terminal hole 121. In this embodiment, the electrode terminal 20 passes through the terminal hole 121 and is fixedly attached to the first end wall 101, and the insulating sealing member 30 is sandwiched between the electrode terminal 20 and the first end wall 101 to achieve an insulating and sealing connection between the electrode terminal 20 and the first end wall 101. 4 , in one embodiment of the present invention, the electrode terminal 20 includes a conductive portion 203, a first fixing portion 204, and a second fixing portion 205. The conductive portion 203 has a cylindrical structure. The conductive portion 203 passes through the terminal hole 121. The first fixing portion 204 is disposed circumferentially at the outer end (the end away from one side of the electrode assembly 40) of the conductive portion 203 and is clamped to the outer end (away from one side of the electrode assembly 40) of the first end wall 101. The second fixing portion 205 is disposed circumferentially at the inner end (the end facing one side of the electrode assembly 40) of the conductive portion 203 and is clamped to the inner side (facing one side of the electrode assembly 40) of the first end wall 101. The electrode terminal 20 is electrically sealed to the first end wall 101 via an insulating sealing member 30.

[0036] As shown in FIGS. 3 and 4 , an electrode assembly 40 is housed within the housing 10. The electrode assembly 40 is a component that causes an electrochemical reaction within the secondary battery 100. One or more electrode assemblies 40 may be housed within the housing 10. The electrode assembly 40 is typically formed by winding or stacking positive and negative electrode pieces, with a separator typically disposed between the positive and negative electrode pieces. The positive electrode piece includes a positive electrode current collector and a positive electrode active material layer, with the positive electrode active material layer coated on the surface of the positive electrode current collector. The positive electrode current collector includes a positive electrode coating area and a positive electrode tab connected to the positive electrode coating area. The positive electrode coating area is coated with the positive electrode active material layer, and the positive electrode tab is not coated with the positive electrode active material layer. The negative electrode piece includes a negative electrode current collector and a negative electrode active material layer, with the negative electrode active material layer coated on the surface of the negative electrode current collector. The negative electrode current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area. The negative electrode coating area is coated with a negative electrode active material layer, and the negative electrode tab is not coated with a negative electrode active material layer. Taking a lithium-ion battery as an example, the positive electrode current collector may be made of aluminum, the positive electrode active material layer includes a positive electrode active material, which may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode current collector may be made of copper, and the negative electrode active material layer includes a negative electrode active material, which may be carbon or silicon. The separator may be made of polypropylene (PP) or polyethylene (PE), etc. The electrode assembly 40 may be covered with an insulating film to protect and insulate the battery core. The insulating film may be synthesized from PP, PE, PET, PVC, or other polymer materials.

[0037] 3 and 4, in one example of a secondary battery 100 of the present invention, an electrode assembly 40 is hermetically installed within the housing 10. The electrode assembly 40 has a first electrode tab 41 and a second electrode tab disposed at both ends of the secondary battery 100 in the height direction, respectively, and the first electrode tab 41 and the second electrode tab have opposite electrode properties. Here, the first electrode tab 41 faces one side of the first end wall 101 and is a positive electrode tab. It should be noted that in other embodiments, the first electrode tab 41 may be a negative electrode tab, and the second electrode tab 41 may be a positive electrode tab.

[0038] 3 to 6 , the current collecting member 50 is disposed within the housing 10 and is located between the first electrode tab 41 and the electrode terminal 20. The current collecting member 50 includes a main body 51 and a terminal connection portion 52. The main body 51 is disposed to surround the terminal connection portion 52. The main body 51 and the terminal connection portion 52 may be integrally molded and connected, or may be connected by welding or any other connection method that meets the connection requirements. The main body 51 is fixedly connected to the first electrode tab 41, and the terminal connection portion 52 and the electrode terminal 20 are fixedly connected toward one side of the electrode assembly 40. The fixed connection method may be welding, adhesive connection, or any other method that meets the connection requirements. In this embodiment, the main body 51 and the first electrode tab 41, and the terminal connection portion 52 and the electrode terminal 20 are fixedly connected by welding.

[0039] 3, 5, and 6, in an embodiment of the present invention, the main body portion 51 includes a deformable portion 511 connected to the terminal connection portion 52. When the internal pressure of the housing 10 exceeds a threshold value, the explosion-proof notch 122 breaks, causing the explosion-proof region 123 to at least partially separate from the housing 10. When the explosion-proof region 123 separates from the housing 10 due to the effect of the internal pressure of the housing 10, the explosion-proof region 123 moves away from the electrode assembly 40, carrying the electrode terminal 20 with it. At the same time, the electrode terminal 20 drives the terminal connection portion 52 to move relative to the main body portion 51, and at this time, the deformable portion 511 deforms to maintain a connection between at least a portion of the terminal connection portion 52 and the main body portion 51. The deformable portion 511 and the terminal connection portion 52 can be connected in various ways. For example, the deformable portion 511 may be directly connected to the terminal connection portion 52, or the deformable portion 511 may be indirectly connected to the terminal connection portion 52. The deformable portion 511 and the terminal connection portion 52 may be formed separately and then connected by welding, or the deformable portion 511 and the terminal connection portion 52 may be integrally molded and then connected, as long as the connection strength requirements between the deformable portion 511 and the terminal connection portion 52 are met.

[0040] The deformable portion 511 may have various options for the specific structure. For example, the deformable portion 511 may have a curved structure, and when the explosion-proof notch 122 is not broken, the curved structure is in a bent state. When the explosion-proof notch 122 is broken and the explosion-proof region 123 is separated from the housing 10, the curved structure changes to a straight state under the effect of internal pressure. That is, by changing from a curved state to a straight state, the length of the deformable portion 511 in the axial direction is changed, and the axial displacement requirement between the explosion-proof region 123 and the housing 10 is met, thereby ensuring a sufficient pressure release area on the first end wall 101. The deformable structure may be a foldable structure, and when the anti-explosion notch 122 is not broken, the foldable structure is in a flat state, but when the anti-explosion notch 122 is broken and the anti-explosion region 123 is separated from the housing 10, the foldable structure is folded toward the side away from the electrode assembly 40 under the effect of internal pressure, thereby realizing the displacement change of the deformable part 511 in the axial direction, thereby meeting the axial displacement requirement between the anti-explosion region 123 and the housing 10 and ensuring a sufficient pressure release area on the first end wall 101. The deformable structure may be a flexible conductive member. When the anti-explosion notch 122 is not broken, the flexible conductive portion is in a relaxed state, but when the anti-explosion notch 122 is broken and the anti-explosion region 123 is separated from the housing 10, the flexible conductive member moves toward the side away from the electrode assembly 40 under the effect of internal pressure and changes to an elongated state, thereby realizing the displacement of the deformable portion 511 in the axial direction, thereby meeting the axial displacement requirement between the anti-explosion region 123 and the housing 10 and ensuring a sufficient pressure release area on the first end wall 101. The deformable structure may also be an elastic conductive member. When the anti-explosion notch 122 is not broken, the elastic conductive member is in a compressed state, but when the anti-explosion notch 122 is broken and the anti-explosion area 123 is separated from the housing 10, the elastic conductive member bounces up toward the side away from the electrode assembly 40 due to the effect of elastic force and internal pressure, thereby realizing the axial displacement of the deformable portion 511, thereby meeting the axial displacement requirement between the anti-explosion area 123 and the housing 10 and ensuring a sufficient pressure release area on the first end wall 101.

[0041] In the secondary battery 100 according to the present invention, both the explosion-proof notch 122 and the electrode terminal 20 are disposed on the first end wall 101 of the housing 10. This allows for a same-side arrangement between the explosion-proof notch 122 and the electrode terminal 20, allowing the electrical connection between battery module levels and the thermal runaway system to be located on the same side of the battery module. This allows the cooling system to be located on another side of the battery module, reducing the horizontal dimension of the battery module, which is advantageous for improving the energy density of the battery module. At the same time, in the secondary battery 100 according to the present invention, the deformable portion 511 is disposed on the main body 51 of the current collecting member 50. When the explosion-proof region 123 separates from the housing 10, the deformable portion 511 deforms, causing a certain displacement of the terminal connection portion 52 in the axial direction relative to the main body 51. On the one hand, when the explosion-proof region 123 separates from the housing 10, the explosion-proof region 123 can drive the electrode terminal 20 and the terminal connecting portion 52 to generate a certain displacement in the axial direction, thereby providing a sufficient pressure relief area on the first end wall 101 and satisfying the pressure relief requirements of the secondary battery 100. On the other hand, the deformable portion 511 deforms and offsets part of the tensile force by the terminal connecting portion 52 toward the outside of the housing 10, thereby reducing the probability that the terminal connecting portion 52 will separate from the main body portion 51. This reduces the probability that the explosion-proof region 123 and the electrode terminal 20 will fly out of the housing 10, thereby avoiding serious problems such as short circuits between other secondary batteries 100 and thermal runaway, and improving the safety performance of the battery module.

[0042] 5 to 8, in one example of a secondary battery 100 according to the present invention, the terminal connection portion 52 is disposed within a central region of the main body portion 51, and the deformable portion 511 includes a first curved structure 5111 surrounding the terminal connection portion 52. The first curved structure 5111 may be a circular ring structure surrounding the outer periphery of the terminal connection portion 52, or may be any closed structure, such as a rectangular ring structure. The cross-sectional shape of the first curved structure 5111 may be a protruding structure, a wavy structure, or a concave-convex structure, as long as the first curved structure 5111 deforms when the explosion-prevention notch 122 is broken, causing axial displacement of the secondary battery 100 along the axial direction due to the influence of the internal pressure of the housing 10. In this embodiment, referring to FIG. 6, the main body portion 51 includes a first region 515 and a second region 516 surrounding the outer periphery of the first region 515. The terminal connection portion 52 is connected to the first region 515, and a side of the first curved structure 5111 closer to the terminal connection portion 52 is connected to the first region 515, while another side of the first curved structure 5111 away from the terminal connection portion 52 is connected to the second region 516, thereby realizing an indirect connection between the first curved structure 5111 and the terminal connection portion 52. Of course, in other embodiments, the first curved structure 5111 may be directly connected to the terminal connection portion 52. In this embodiment, when the main body portion 51 is connected to the first electrode tab 41 by welding, the first region 515 and the first electrode tab 41 may be connected by welding, or the second region 516 and the first electrode tab 41 may be connected by welding, or both the first region 515 and the second region 516 and the first electrode tab 41 may be connected by welding, as long as the welding connection requirement between the first electrode tab 41 and the main body portion 51 is satisfied. By positioning the first curved structure 5111, when the explosion-proof region 123 separates from the housing 10, the first curved structure 5111 causes axial deformation, and meets the displacement requirements of the explosion-proof region 123 when driving the electrode terminal 20 and the terminal connection portion 52 along the axial direction, thereby forming a sufficient pressure release area on the first end wall 101 and meeting the pressure release requirements of the secondary battery 100.At the same time, because the first curved structure 5111 is connected to the first region 515 and the second region 516, when the explosion-proof region 123 is separated from the housing 10, a tensile force is formed between the terminal connection part 52 and the first region 515 and the second region 516, thereby reducing the probability that the explosion-proof region 123, the electrode terminal 20, and the terminal connection part 52 will fly out of the housing 10, thereby avoiding serious problems such as short circuits between other secondary batteries in the battery module and thermal runaway, and improving the safety performance of the battery module.

[0043] 3 and 8 , in one example of the secondary battery 100 of the present invention, the first curved structure 5111 includes a first recess 51112 and a first protrusion 51111. The first recess 51112 is recessed from one side of the main body portion 51 toward another side of the main body portion 51, and the first protrusion 51111 is correspondingly formed on the other side of the main body portion 51. The protrusion direction of the first protrusion 51111 along the height direction of the secondary battery 100 is not particularly limited, and may be, for example, a protrusion toward the side facing the electrode assembly 40 or a protrusion toward the side away from the electrode assembly 40. With this arrangement, on the one hand, when the explosion-proof region 123 separates from the housing 10, the first curved structure 5111 can quickly generate axial deformation, thereby accelerating the speed at which the explosion-proof region 123 drives the electrode terminal 20 and the terminal connection portion 52 to move along the axial direction, and improving the timeliness of pressure release of the secondary battery 100. On the other hand, this arrangement also facilitates integrated stamping molding of the first curved structure 5111, thereby improving the efficiency of forming the first curved structure 5111. The arrangement of the first protrusions 51111 and the second recesses 202 is also advantageous in improving the rigidity of the main body portion 51 and reducing stress deformation that occurs when the main body portion 51 and the first electrode tab 41 are connected by welding.

[0044] The first protrusion 51111 may be a protrusion facing the side facing the electrode assembly 40 or a protrusion facing the side away from the electrode assembly 40. However, preferably, referring to FIGS. 3 to 8 , in one example of a secondary battery 100 according to the present invention, the first protrusion 51111 is arranged on the side facing the first end wall 101 of the main body 51. That is, the first protrusion 51111 protrudes toward one side of the first end wall 101. The first recess 51112 is arranged on the side of the main body 51 facing the electrode assembly 40. That is, the first recess 51112 is recessed toward the side away from the electrode assembly 40. With this arrangement, the first protrusion 51111 does not abut against the first electrode tab 41 in the height direction of the secondary battery 100, so that the welded connection between the main body 51 and the first electrode tab 41 is not affected and is advantageous for the welded connection between the electrode tab 41 and the current collecting member 50.

[0045] 7 , in one example of a secondary battery 100 according to the present invention, the first protrusions 51111 are arranged in a ring shape and surround the outer periphery of the terminal connection portion 52. The specific position of the first protrusions 51111 relative to the terminal connection portion 52 is not particularly limited. The terminal connection portion 52 may be located at the center of the area surrounded by the first protrusions 51111, or may be located at another position within the area surrounded by the first protrusions 51111, as long as the first protrusions 51111 are arranged in a ring shape and surround the outer periphery of the terminal connection portion 52. This arrangement reduces stress concentration caused by the first protrusions 51111, thereby improving the overall strength consistency of the first protrusions 51111. In addition, in another embodiment of the present invention, by arranging the first protrusion 51111 and the terminal connection portion 52 coaxially, not only is it easier to perform positioning processing between the first protrusion 51111 and the terminal connection portion 52, but it is also possible to ensure that the first protrusion 51111 and the terminal connection portion 52 obtain a uniform connection force in the circumferential direction, thereby ensuring the uniformity of the deformation of the first curved structure when the anti-explosion notch is separated from the housing 10, and thereby ensuring the consistency of the pressure release area and pressure release effect of the secondary battery 100.

[0046] 7 to 9, in one example of the secondary battery 100 according to the present invention, the width of the first protrusion 51111 along the radial direction of the secondary battery 100 is 2 to 10 mm, and preferably 3 to 6 mm. The height of the first protrusion 51111 along the axial direction of the secondary battery 100 is 1 to 5 mm, and preferably 1 to 2 mm. The first protrusion 51111 includes an annular upper wall 517, and an inner annular wall 518 and an outer annular wall 519 connected to the annular upper wall 517. The inner annular wall 518 is connected to the first region 515, and the outer annular wall 519 is connected to the second region 516. The annular top wall 517, the inner annular wall 518, and the outer annular wall 519 all have a flat structure, and the annular top wall 517 is disposed parallel to the first region 515 or the second region 516, while the inner annular wall 518 and the outer annular wall 519 may be disposed perpendicular to or oblique to the annular top wall 517. In this embodiment, to facilitate the molding process of the first protrusions 51111, both the inner annular wall 518 and the outer annular wall 519 are disposed obliquely to the annular top wall 517. If the width W of the annular top wall 517 is the width of the first protrusions 51111, the width W of the annular top wall 517 along the radial direction of the secondary battery 100 is 2 to 10 mm, and preferably 3 to 6 mm. If the height H of the inner annular wall 518 is the height of the first protrusion 51111, the height H of the inner annular wall 518 along the axial direction of the secondary battery 100 is 1 to 5 mm, and preferably 1 to 2 mm, and the height of the first protrusion 51111 does not exceed the height of the terminal connection portion 52 on the same side. By controlling the width W of the annular upper wall 517 and the height H of the inner annular wall 518, it is possible to control the maximum displacement that the first protrusion 51111 can cause in the axial direction, and therefore the maximum distance that the explosion-preventive region 123 can move in the axial direction when the explosion-preventive notch 122 is ruptured, and thereby it is possible to control the size of the pressure release area of ​​the secondary battery 100. In this embodiment, the width W of the annular upper wall 517 is set to 3 to 6 mm, and the height H of the inner annular wall 518 is set to 1 to 2 mm, which not only meets the requirements for the pressure release area of ​​the secondary battery 100, but also prevents the first protrusion 51111 from occupying a large space inside the housing 10, thereby reducing the impact on the energy density of the secondary battery 100.

[0047] 3, 6, 7, and 8, in one example of the secondary battery 100 of the present invention, the first protrusion 51111 is formed in an annular shape, and the outer diameter of the first protrusion 51111 is ≦38 mm. Specifically, the annular upper wall 517 has a circular ring structure, the outer annular wall 519 and the inner annular wall 518 have a generally trapezoidal structure, and the small ends of the outer annular wall 519 and the inner annular wall 518 both point in a direction away from the first region 515. The diameter D of the large end of the outer annular wall 519 is the outer diameter of the first protrusion 51111, and the diameter D of the large end of the outer annular wall 519 is 38 mm or less. The size of the diameter D of the large end of the outer annular wall 519 directly affects the position of the first protrusion 51111 on the main body portion 51, and therefore affects the area sizes of the first region 515 and the second region 516. In this embodiment, by setting the diameter D of the large end of the outer annular wall 519 to 38 mm or less, on the one hand, the minimum area of ​​the second region 516 can be limited, so that the area of ​​the second region 516 can meet the area requirement for connection to the first electrode tab 41 by welding, thereby reducing the influence of the first protrusion 51111 on the welding position of the first electrode tab 41. On the other hand, because the first region 515 is not connected to the first electrode tab 41 by welding, the resistance force of the first region 515 when it extends out of the housing 10 when the explosion-proof region 123 is separated from the housing 10 can be reduced, thereby accelerating the pressure release speed of the secondary battery 100.

[0048] 2 to 4, in one example of secondary battery 100 of the present invention, the welding strength between electrode terminal 20 and terminal connection portion 52 is greater than 50 N. When explosion-proof notch 122 breaks and electrode terminal 20 is driven so that explosion-proof region 123 separates from casing 10, electrode terminal 20 and terminal connection portion 52 are subjected to a large tensile force due to the influence of the internal pressure of casing 10. If this tensile force exceeds the welding strength between electrode terminal 20 and terminal connection portion 52, electrode terminal 20 and terminal connection portion 52 will separate from each other, driving electrode terminal 20 so that explosion-proof region 123 pops out of casing 10, which may risk affecting safety at the battery module level. In this embodiment, by setting the welding connection strength between the electrode terminal 20 and the terminal connection portion 52 to be greater than 50 N, the connection strength between the electrode terminal 20 and the terminal connection portion 52 can be made to match the amount of tensile force generated between the electrode terminal 20 and the terminal connection portion 52 when the anti-explosion notch 122 breaks, thereby effectively reducing the probability that the electrode terminal 20 will separate from the terminal connection portion 52, and thereby reducing the probability that the electrode terminal 20 will fly out of the housing 10 when the anti-explosion notch 122 breaks.

[0049] In this embodiment, there are many options for testing the strength of the welded connection between the electrode terminal 20 and the terminal connection part 52. However, preferably, in this embodiment, a tool is used to clamp the terminal connection part 52 along the height direction of the secondary battery 100, and the terminal connection part 52 is pulled toward the side away from the electrode terminal 20, while gradually increasing the pulling force at a speed of 1 N / S during the movement process until the welded connection between the terminal connection part 52 and the electrode terminal 20 breaks. At this time, the corresponding pulling force after the test is the value of the welded connection strength between the electrode terminal 20 and the terminal connection part 52.

[0050] 2 to 4 , in one example of a secondary battery 100 according to the present invention, a thinned region 201 is disposed in the thickness direction of the electrode terminal 20, and the terminal connection portion 52 and the thinned region 201 abut against each other and are connected by welding. The area and shape of the thinned region 201 are not particularly limited, and may be, for example, square, circular, annular, or a special shape, as long as the size of the welding area of ​​the terminal connection portion 52 is met. The welding method is also not particularly limited, and may be such that the thinned region 201 and the terminal connection portion 52 can be welded from the outside of the casing 10. However, when the thickness of the thinned region 201 exceeds the thickness of the terminal connection portion 52, welding from the outside of the casing 10 requires penetrating the thinned region 201. This requires the use of a high-energy laser, but the amount of laser energy is difficult to control. Direct welding may result in leakage from the electrode terminal 20 or non-wetting defects due to insufficient energy. In this embodiment, the thinned region 201 can be arranged to adjust the thickness relationship between the electrode terminal 20 and the terminal connection portion 52, so that the thickness of the thinned region 201 not only meets the welding requirements, but also prevents excessive heat from being transferred to the electrode assembly 40, and improves the problems of non-wetting defects and welding through caused by the thickness mismatch between the electrode terminal 20 and the terminal connection portion 52 during welding.

[0051] 4 and 8 , in one example of the secondary battery 100 of the present invention, the electrode terminal 20 has a second recess 202 disposed on the side facing the electrode assembly 40, and the terminal connection portion 52 has a second protrusion 521 disposed on the side facing the electrode terminal 20. The second protrusion 521 and the second recess 202 abut against each other and are connected by welding. The shape of the second recess 202 can be set to match the shape of the second protrusion 521. For example, the second recess 202 can be circular, rectangular, or other structure, and the second protrusion 521 can be set to a corresponding circular, rectangular, or other structure. In this way, not only can the positioning connection between the second protrusion 521 and the second recess 202 be achieved, but also the installation space occupied in the height direction of the housing 10 can be reduced, which is advantageous for improving the energy density of the secondary battery 10. Of course, the shape of the second recess 202 does not have to match the shape of the second protrusion 521. For example, the second recess 202 may be set to a circular shape and the second protrusion 521 may be set to a rectangular shape, as long as the second protrusion 521 is reliably accommodated in the second recess 202.

[0052] The method for forming the connection between the terminal connection portion 52 and the main body portion 51 is not particularly limited and may be, for example, welding, adhesive bonding, or integral molding, as long as the connection strength requirements between the terminal connection portion 52 and the main body portion 51 are met. In one example of the secondary battery 100 of the present invention, the terminal connection portion 52 and the main body portion 51 are integrally molded and connected. The integrally molded connection may be integral stamping, integrated casting molding, or additive molding. In this embodiment, by arranging the terminal connection portion 52 and the main body portion 51 as an integrally molded part, the assembly efficiency of the current collecting member 50 can be improved, thereby improving the assembly efficiency of the secondary battery 100.

[0053] 8 to 10 , in one example of a secondary battery 100 according to the present invention, the terminal connection portion 52 and the main body portion 51 are separately configured, and the thickness of the terminal connection portion 52 is greater than the thickness of the main body portion 51. The terminal connection portion 52 can be fixedly connected to the main body portion 51 by welding, adhesive, or other methods. In this embodiment, the terminal connection portion 52 has an approximate protrusion column structure. Along the height direction of the secondary battery 100, one end of the terminal connection portion 52 is connected to the thinned region 201 by welding, and the other end of the terminal connection portion 52 is connected to the surface of one end of the main body portion 51 by welding. By separately configuring the terminal connection portion 52 and the main body portion 51, the thickness of the terminal connection portion 52 can be easily adjusted, and the thickness of the terminal connection portion 52 is greater than the thickness of the main body portion 51. As a result, the welding parameters between the thinned region 201 and the terminal connection portion 52 can be improved, which is advantageous for improving the welding quality between the electrode terminal 20 and the terminal connection portion 52 and ensuring the strength of the welding connection between the electrode terminal 20 and the terminal connection portion 52.

[0054] 10 , in one example of secondary battery 100 of the present invention, terminal connection portion 52 is connected to main body portion 51 by welding, and the welded connection strength is greater than 50 N. By setting the welded connection strength between terminal connection portion 52 and main body portion 51 to be greater than 50 N, the connection strength between terminal connection portion 52 and main body portion 51 can be matched to the amount of tensile force generated between terminal connection portion 52 and main body portion 51 when anti-explosion notch 122 is ruptured, which effectively reduces the probability that terminal connection portion 52 will be separated from main body portion 51 and thereby reduces the probability that terminal connection portion 52 will be driven to cause electrode terminal 20 to jump out of housing 10.

[0055] The welding method between the terminal connection portion 52 and the main body portion 51 is not particularly limited, and may be, for example, seam welding or penetration welding. However, referring to FIG. 10 , in one example of a secondary battery 100 of the present invention, the terminal connection portion 52 and the main body portion 51 are preferably connected by penetration welding. Because the thickness of the terminal connection portion 52 is greater than the thickness of the main body portion 51, when penetration welding is performed on one side of the main body portion 51 to the terminal connection portion 52, the welding quality is good. A weld mark 53 is formed between the main body portion 51 and the terminal connection portion 52. The weld mark 53 has a ring-shaped structure, and the number of revolutions of the weld mark 53 is at least two. For example, the number of revolutions of the weld mark 53 may be two or three. The specific distribution position of the weld mark 53 on the terminal connection portion 52 is not particularly limited. However, in this embodiment, the weld mark 53 and the terminal connection portion 52 are preferably arranged coaxially, and the number of revolutions of the weld mark 53 is two. By limiting the number of weld marks 53 between the terminal connection portion 52 and the main body portion 51 to at least two circumferences, the flow area of ​​the electrical connection between the terminal connection portion 52 and the main body portion 51 can be secured, and the strength of the weld connection between the terminal connection portion 52 and the main body portion 51 can be secured, thereby reducing the probability of disconnection between the terminal connection portion 52 and the main body portion 51 when the anti-explosion notch 122 breaks.

[0056] 11 to 13 , in one example of a secondary battery 100 according to the present invention, a main body portion 51 includes a support portion 512 arranged in an annular shape, a terminal connection portion 52 is located within a central region of the support portion 512, and a deformable portion 511 includes a weakened portion 5112 extending from the support portion 512 to the terminal connection portion 52, and the terminal connection portion 52 is connected to the main body portion 51 via the weakened portion 5112. The shape and area of ​​the support portion 512 are not particularly limited. In this embodiment, the support portion 512 has a circular ring structure, and the terminal connection portion 52 has a protruding column structure, and the terminal connection portion 52 and the support portion 512 are arranged coaxially. Naturally, in other embodiments, the terminal connection portion 52 may have a structure with a different shape. The support portion 512 abuts against and is pressed firmly against the first electrode tab 41. The current collecting member 50 may be connected to the first electrode tab 41 by welding via the support portion 512, or may be connected to the first electrode tab 41 by welding via another arranged part, but the present invention is not limited thereto.

[0057] The weak portion 5112 extends along the radial direction of the support portion 512. One end of the weak portion 5112 is directly connected to the terminal connection portion 52, and the other end of the weak portion 5112 is directly connected to the support portion 512. The specific shape and area of ​​the weak portion 5112 are not particularly limited. The weak portion 5112 may have any shape, such as an arc shape or a strip shape. In this embodiment, the weak portion 5112 has a strip-like structure, and the extension direction of the strip shape coincides with the radial direction of the support portion 512. The connection method between the weak portion 5112 and the support portion 512 and between the weak portion 5112 and the terminal connection portion 52 may be a welded connection or an integrally molded connection, as long as the connection strength requirement is met. In this embodiment, referring to FIGS. 13 to 15, the weakened portion 5112 and the supporting portion 512 are connected by integral stamping, and the weakened portion 5112 and the terminal connecting portion 52 are connected by welding.

[0058] Because the weakened portion 5112 has a cantilevered structure, the weakened portion 5112 has weak strength and rigidity, and when the explosion-proof notch 122 breaks, the explosion-proof region 123 drives the terminal connection portion 52 to move toward the outside of the housing 10. When the main body portion 51 is pulled, the weakened portion 5112 is folded toward the outside of the housing 10. In this way, when the explosion-proof region 123 is separated from the housing 10, the explosion-proof region 123 can drive the electrode terminal 20 and the terminal connection portion 52 to generate a certain displacement relative to the housing 10, thereby ensuring a sufficient pressure release area on the first end wall 101 and meeting the pressure release requirements of the secondary battery 100. Furthermore, the weakened portion 5112 applies a tensile force to the terminal connection portion 52, reducing the probability that the terminal connection portion 52 will separate from the main body portion 51. At the same time, the weak portion 5112 can be designed to have a large size in the radial extension direction, and when the weak portion 5112 is folded, the terminal connection portion 52 can obtain a large axial displacement, which is advantageous for forming a large pressure release area, thereby accelerating the pressure release speed of the secondary battery 100.

[0059] It should be mentioned that the weakened portion 5112 may or may not be connected to the first electrode tab 41 by welding, but the present invention is not limited thereto. In this embodiment, the weakened portion 5112 is not connected to the first electrode tab 41 by welding, and therefore, the welding connection resistance that occurs when the weakened portion 5112 is folded can be reduced.

[0060] 14, 16, and 17, in one example of the secondary battery 100 of the present invention, the weak portion 5112 includes a bending guide portion 513 that guides the weak portion 5112 so that the weak portion 5112 bends. The specific structure of the bending guide portion 513 is not particularly limited, and may be, for example, a curved or folded structure corresponding to the bending direction of the weak portion 5112. The specific position of the bending guide portion 513 on the weak portion 5112 is not particularly limited, but in this embodiment, the bending guide portion 513 is preferably disposed near one side of the support portion 512 so that the weak portion 5112 can achieve a large folding size and the terminal connection portion 52 can generate a large axial displacement. By arranging a bending guide structure within the weak portion 5112, a guide effect can be obtained when the weak portion 5112 is bent, so that not only can the weak portion 5112 bend sharply, but also the consistency of the degree of folding of the weak portion 5112 within the housing 10 can be achieved, thereby ensuring the consistency of the pressure release effect of the secondary battery 100.

[0061] 16 and 17 , in one example of the secondary battery 100 of the present invention, the bending guide portion 513 includes a second curved portion 5131, which is disposed on a side of the weak portion 5112 closer to the support portion 512. The second curved portion 5131 may have any structure, such as a protrusion structure, a recess structure, or a structure combining protrusions and recesses. In this embodiment, the second curved portion 5131 has a protrusion structure facing the electrode terminal 20. The extension direction of the second curved portion 5131 is perpendicular to the extension direction of the weak portion 5112, thereby providing an excellent folding guide effect for the weak portion 5112. Of course, in other embodiments, the extension direction of the second curved portion 5131 may be disposed at a different angle relative to the extension direction of the weak portion 5112, as long as the folding guide effect is obtained. By positioning the second curved portion 5131, the weak portion 5112 forms a stress change area at the position of the second curved portion 5131, and then when the weak portion 5112 is folded, it is first folded and deformed from the stress change area, thereby achieving a guiding effect for the folding operation of the weak portion 5112.

[0062] Referring to FIG. 14 , in one example of the secondary battery 100 of the present invention, the bending guide portion 513 includes a fold 5132, which is disposed on a side of the weak portion 5112 closer to the support portion 512. The direction of the fold 5132 coincides with the folding direction of the weak portion 5112, and the extension direction of the fold 5132 is perpendicular to the extension direction of the weak portion 5112. In other embodiments, the extension direction of the fold 5132 may be set at other angles relative to the extension direction of the weak portion 5112, as long as a folding guide effect is achieved. By disposing the fold 5132 on the weak portion 5112, a predetermined folding position can be formed on the weak portion 5112. When the weak portion 5112 is folded, it can be folded along the predetermined folding position, thereby achieving a guide effect for the folding operation of the weak portion 5112.

[0063] 12 to 14 , in one example of the secondary battery 100 of the present invention, the main body 51 further includes a plurality of electrode tab connection portions 514, which extend from the support portion 512 toward the center of the electrode assembly 40 and are spaced apart from the terminal connection portion 52. The electrode tab connection portions 514 are connected to the first electrode tab 41 by welding. The electrode tab connection portions 514 may be, for example, integrally connected, separated, or have a cavity between adjacent electrode tab connection portions 514. The specific shape and number of the electrode tab connection portions 514 are not particularly limited. In this embodiment, the electrode tab connection portions 514 have a strip-shaped structure. The electrode tab connection portions 514 extend along the radial direction of the support portion 512 and are alternately arranged in the circumferential direction of the support portion 512, with hollow regions 5141 formed between adjacent electrode tab connection portions 514. None of the electrode tab connection portions 514 is connected to the terminal connection portion 52 or the weakened portion 5112. This arrangement, on the one hand, does not affect the position of the electrode tab connection portions 514 to cause the weakened portions 5112 to fold outward from the casing 10, thereby not affecting the pressure release effect of the secondary battery 100. On the other hand, because the hollow regions 5141 are formed between the electrode tab connection portions 514, when the explosion-prevention notch 122 is ruptured, the electrode tab connection portions 514 are more likely to fold and tear outward from the casing 10 under the influence of pressure, which further reduces the shielding of the pressure release area on the surface of one end of the electrode assembly 40, advantageously further improving the pressure release effect of the secondary battery 100.

[0064] 11 and 13 , in one example of the secondary battery 100 of the present invention, the orthogonal projection of the explosion-proof region 123 at least partially overlaps with the orthogonal projection of the electrode tab connection portion 514 along the height direction of the secondary battery 100. This arrangement increases the shielding area of ​​the electrode tab connection portion 514 against the surface of the end of the electrode assembly 40, thereby increasing the impact force that the electrode tab connection portion 514 receives when the explosion-proof notch 122 is ruptured, which is advantageous for the electrode tab connection portion 514 to fold and tear toward the outside of the casing 10, thereby further increasing the pressure release effect of the secondary battery 100.

[0065] 11 and 13, in one example of the secondary battery 100 of the present invention, the orthogonal projection of the support portion 512 along the height direction of the secondary battery 100 is located outside the orthogonal projection of the explosion-proof area 123 and does not overlap with the orthogonal projection of the explosion-proof area 123. This arrangement is advantageous in improving the pressure release effect of the secondary battery 100, as it can further reduce the shielding of the support portion 512 from the pressure release area on the surface of one end of the electrode assembly 40.

[0066] 3 and 4 , in one example of a secondary battery 100 of the present invention, the insulating sealing member 30 includes a first insulating member 31, a second insulating member 32, and a sealing member 33. The first insulating member 31 is positioned between the inner surface of the first end wall 101 and the current collecting member 50. The first insulating member 31 is pressed and fixed to the inner surface of the first end wall 101 via the second fixing portion 205 of the electrode terminal 20, thereby achieving an insulating connection between the inner surface of the first end wall 101 and the electrode terminal 20. The first insulating member 31 is at least partially positioned between the terminal hole 121 and the conductive portion 203, thereby achieving an insulating connection between the conductive portion 203 and the terminal hole 121. The second insulating member 32 is positioned between the first fixing portion 204 and the outer surface of the first end wall 101. The second insulating member 32 is pressed and fixed to the outer surface of the first end wall 101 via the first fixing portion 204, thereby establishing an insulating connection between the first fixing portion 204 and the outer surface of the first end wall 101. The sealing member is pressed and fixed between the outer surface of the first end wall 101 and the first fixing portion 204, thereby establishing a sealed connection between the electrode terminal 20 and the terminal hole 121. Along the height direction of the secondary battery 100, the orthogonal projection of the first insulating member 31 is located within the orthogonal projection of the explosion-proof region 123. In this way, the installation position of the first insulating member 31 on the first end wall 101 does not block the position of the explosion-proof notch 122, thereby not affecting the pressure release effect of the secondary battery 100.

[0067] Referring to FIG. 18 , in one example of a secondary battery 100 according to the present invention, the insulating sealing member 30 further includes a third insulating member 34. The third insulating member 34 is disposed in the area of ​​the inner surface of the first end wall 101 that is not covered by the first insulating member 31. The third insulating member 34 may be an insulating washer. The insulating washer may be fixedly connected to the inner surface of the first end wall 101 or may be directly sandwiched between the first electrode tab 41 and the inner surface of the first end wall 101, as long as it achieves an insulating effect in the area of ​​the inner surface of the first end wall 101 that is not covered by the first insulating member 31. In another embodiment, the third insulating member 34 may be an insulating layer. The insulating layer is applied to the area of ​​the inner surface of the first end wall 101 that is not covered by the first insulating member 31. In this way, an insulating effect is achieved even in the area of ​​the inner surface of the first end wall 101 that is not covered by the first insulating member 31. Of course, in other embodiments, the third insulating member 34 may not be arranged, and the area of ​​the inner surface of the first end wall 101 that is not covered by the first insulating member 31 is insulated from the opposing electrode assemblies 40 by a gap.

[0068] It should be mentioned that in order to reduce the influence of the third insulating member 34 on the explosion-proof notch 122, in the embodiment according to the present invention, the third insulating member 34 does not cover the area of ​​the explosion-proof notch 122 on the first end wall 101.

[0069] 19 , in one example of a secondary battery 100 of the present invention, the side of the electrode assembly 40 facing the electrode terminal 20 is covered with insulating tape 35. The insulating tape 35 covers and fixes the current collecting member 50 on the electrode assembly 40, so that a portion of the surface of the current collecting member 50 facing the first end wall 101 is covered with the insulating tape 35. The area of ​​the current collecting member 50 covered by the insulating tape 35 along the height direction of the secondary battery 100 is the orthogonal projection of the insulating tape 35 on the surface of the end of the current collecting member 50 that covers the region of the inner surface of the first end wall 101 that is not covered by the first insulating member 31. In this way, an insulating effect is achieved even in the region of the inner surface of the first end wall 101 that is not covered by the first insulating member 31.

[0070] 11, 20, and 21, in one example of a secondary battery 100 of the present invention, the first insulating member 31 includes a first annular body 311 and a second annular body 312 located on the outer periphery of the first annular body 311. The first annular body 311 and the second annular body 312 are detachably connected via a snap-in structure 313, which includes a snap-in protrusion 3131 and a snap-in groove 3132. The snap-in protrusion 3131 is disposed in the first annular body 311, and the snap-in groove 3132 is disposed in the second annular body 312, and the snap-in protrusion 3131 snaps into the corresponding snap-in groove 3132. In another embodiment, the snap-in protrusion 3131 may be disposed on the second annular body 312, and the snap-in groove 3132 may be disposed on the first annular body 311. The snap-in structure 313 allows for a detachable connection between the first annular body 311 and the second annular body 312, and enables the first insulating member 31 to be configured as a separate structure rather than an integral structure, thereby alleviating problems such as molding process defects and unstable material properties that arise due to the large overall structure. At the same time, the snap-in structure 313, consisting of the snap-in protrusion 3131 and the snap-in groove 3132, is provided, thereby improving the positioning accuracy and assembly efficiency between the first annular body 311 and the second annular body 312.

[0071] 20 and 21 , in one example of the secondary battery 100 of the present invention, the first annular body 311 is made of a PFA material, and the second annular body 312 is made of a different material. Because the insulation requirements between the electrode terminal 20 and the terminal hole 121 are different from those between the first end wall 101 and the electrode assembly 40, the material performance requirements for the first annular body 311 and the second annular body 312 are typically different. In this embodiment, the first annular body 311 is made of a PFA material. PFA material has excellent insulation properties and is suitable for meeting the insulation requirements between the electrode terminal 20 and the terminal hole 121, but its material cost is high. The second annular body 312 may be made of a common insulating material that meets the performance requirements, such as LCP, PPS, or PP, and has low material cost. Preferably, in this embodiment, the second annular body 312 is made of an LCP material. This arrangement can satisfy the insulation performance requirements of the first insulating member 31 while simultaneously reducing the overall material cost of the first insulating member 31. Of course, if material cost is not a consideration, in other embodiments, the material of the second annular body 312 may be PFA.

[0072] 11, 20, and 21, in one example of the secondary battery 100 of the present invention, the first annular body 311 includes a protruded stage 3111 extending toward the first end wall 101, the protruded stage 3111 extends into the terminal hole 121, the outer diameter of the protruded stage 3111 matches the diameter of the terminal hole 121, and the inner diameter of the protruded stage 3111 matches the outer diameter of the conductive portion 203 of the electrode terminal 20, so that at least a portion of the protruded stage 3111 is sandwiched between the side wall 11 of the terminal hole 121 and the side wall 11 of the electrode terminal 20, thereby realizing an insulated connection between the electrode terminal 20 and the terminal hole 121. The first annular body 311 and the second annular body 312 are coaxially arranged along the height direction of the secondary battery 100, and the outer diameter of the first annular body 311 is larger than the inner diameter of the second annular body 312, so that the orthogonal projection plane of the first annular body 311 partially overlaps the orthogonal projection plane of the second annular body 312. In this way, the gap generated during the abutment connection between the first annular body 311 and the second annular body 312 can be eliminated, thereby improving the insulating effect of the first insulating member 31.

[0073] Referring to FIG. 22 , the present invention also provides a battery assembly 200, which includes any of the above-described secondary batteries 100. The battery assembly 200 may be a battery module or a battery pack, but the present invention is not limited thereto. In one embodiment of the present invention, the battery assembly 200 includes a case 210 and at least one secondary battery 100. The case 210 includes a first case 211 and a second case 212. The first case 211 and the second case 212 cover each other to form a storage space. A plurality of secondary batteries 100 are stored in the storage space, and the plurality of secondary batteries 100 may be connected in series and / or parallel.

[0074] The present invention also provides an electronic device 300. The electronic device 300 may be a vehicle, a mobile phone, a portable device, a laptop computer, a boat, a spacecraft, an electronic toy, a power tool, or the like. The vehicle may be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range-extended vehicle, or the like. The spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, or the like. The electronic toys may include stationary or mobile electronic toys, such as a game console, a toy electric car, a toy electric boat, or a toy electric airplane. The power tools may include metal cutting power tools, grinding power tools, assembly power tools, railway power tools, or the like, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, an electric planer, or the like, but the present invention is not limited thereto.

[0075] In the electronic device 300 of the present invention, the electronic device 300 includes a working unit 310 and a battery assembly 200. The working unit 310 is electrically connected to the battery assembly 200 to obtain power energy support. The working unit 310 may be a unit component that can obtain the electric energy of the battery assembly 200 and perform a corresponding operation, such as a blade rotation unit of a fan, a dust collection unit of a vacuum cleaner, or a wheel drive unit of an electric vehicle. The embodiment of the present invention is not limited to the electronic device 300.

[0076] Referring to FIG. 23, in one embodiment of the electronic device 300 of the present invention, the electronic device 300 is a vehicle, the working unit 310 is the main body of the vehicle, and the battery assembly 200 is fixedly installed in the main body and provides driving force to the vehicle to enable it to operate.

[0077] In the secondary battery according to the present invention, both the explosion-proof notch and the electrode terminal are disposed on the end wall of the housing. This allows the explosion-proof notch and the electrode terminal to be disposed on the same side, allowing the electrical connection between battery module levels and the thermal runaway system to be installed on the same side of the battery module. This allows the cooling system to be disposed on another side of the battery module, reducing the horizontal dimension of the battery module, which is advantageous for improving the energy density of the battery module. At the same time, in the secondary battery according to the present invention, the deformable portion is disposed on the main body of the current collecting member. When the explosion-proof region separates from the housing, the deformable portion deforms, causing the terminal connection portion to undergo a certain axial displacement relative to the main body. On the one hand, when the explosion-proof region separates from the housing, the explosion-proof region can drive the electrode terminal and the terminal connection portion to undergo a certain axial displacement, thereby providing a sufficient pressure relief area on the first end wall and thereby meeting the pressure relief requirements of the secondary battery. On the other hand, the deformable portion deforms and offsets part of the tensile force that the terminal connection portion experiences toward the outside of the housing, thereby reducing the probability of the terminal connection portion separating from the main body. Therefore, the probability of the explosion-proof area and electrode terminals flying out of the housing 10 can be reduced, thereby avoiding serious problems such as short circuits between other secondary batteries and thermal runaway, and improving the safety performance of the battery module. Therefore, the present invention effectively overcomes several practical problems in the prior art and has high utility value and practical significance. The above-described embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Those skilled in the art may modify or change the embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or variations made by those skilled in the art without departing from the spirit and technical ideas described in the present invention are still intended to be encompassed by the appended claims. [Industrial Applicability]

[0078] The secondary battery, battery assembly, and electronic device of the present invention can be applied in the field of battery technology. [Explanation of symbols]

[0079] 10. Cabinet 11 Side wall 20 electrode terminal 30 Insulating sealing material 31 First insulating member 32 Second insulating member 33 Sealing member 34 Third insulating member 35 Electrical tape 40 Electrode Assembly 41 First electrode tab 50 Current collecting member 51 Main part 53 Weld marks 100 Secondary battery 101 First end wall 102 Second end wall 121 Terminal hole 122 Explosion-proof notch 123 Explosion-proof area 200 Battery Assembly 201 Thinning area 202 Second recess 203 Conductive part 204 1st fixed part 205 Second fixed part 210 Box body 211 1st box body 212 Second box 300 Electronic equipment 310 Working Unit 311 First Ring 312 Second ring body 313 Snap-in structure 511 Transformable part 512 Support part 513 Bending guide section 514 Electrode tab connection 515 First area 516 Second area 517 Circular upper wall 518 Inner ring wall 519 Outer ring wall 52l 2nd protrusion 3111 Projection part 3131 Snap-in protrusion 3132 Snap-in groove 5111 First curved structure 5112 Weakened part 5131 Second curved structure 5132 crease 5141 Cavity area 51111 1st protrusion 51112 First recess D diameter H Height W width

Claims

1. a housing including an end wall and a side wall surrounding the end wall, the end wall including a terminal hole and an explosion-proof notch surrounding the terminal hole, and an area on the end wall surrounded by the explosion-proof notch being an explosion-proof area; an electrode terminal that covers the terminal hole and is fixed to the end wall, with an insulating sealing member disposed between the electrode terminal and the end wall; an electrode assembly disposed within the housing, the side facing the end wall including a first electrode tab; a current collecting member disposed within the housing, positioned between the first electrode tab and the electrode terminal, the current collecting member including a main body portion and a terminal connection portion, the main body portion being disposed so as to surround the terminal connection portion, the main body portion being connected to the first electrode tab, and the terminal connection portion being connected to an inner surface of the electrode terminal facing the electrode assembly; the main body portion includes a deformable portion connected to the terminal connection portion, and when an internal pressure of the housing is greater than a threshold value, the explosion-proof notch ruptures, the explosion-proof region at least partially separates from the housing, and moves away from the electrode assembly, taking the electrode terminal with it, and the deformable portion deforms, causing the terminal connection portion to be displaced in an axial direction relative to the main body portion, thereby maintaining the connection between the electrode terminal and the main body portion.

2. The secondary battery according to claim 1 , wherein the terminal connection portion is disposed in a central region of the main body portion, and the deformable portion includes a first curved structure surrounding the terminal connection portion.

3. 3. The secondary battery of claim 2, wherein the first curved structure includes a first recess and a first protrusion, the first recess being recessed from one side of the main body portion toward another side of the main body portion, the first protrusion being correspondingly formed on the other side of the main body portion, and the first protrusion being arranged in a ring shape and surrounding an outer periphery of the terminal connection portion.

4. The secondary battery according to claim 3 , wherein the first protrusion is disposed on a side of the main body portion facing the end wall, and the first recess is disposed on a side of the main body portion facing the electrode assembly.

5. 5. The secondary battery according to claim 4, wherein a width of the first protrusions along the radial direction of the secondary battery is 2 mm to 10 mm, and a height of the first protrusions along the axial direction of the secondary battery is 1 mm to 5 mm.

6. The secondary battery according to claim 4 , wherein the first projection is formed in an annular shape and has an outer diameter of 38 mm or less.

7. 2. The secondary battery according to claim 1, wherein the welding strength between the electrode terminal and the terminal connection portion is greater than 50N.

8. The secondary battery according to claim 7 , wherein the electrode terminal has a thinned region arranged along the thickness direction, and the terminal connection portion and the thinned region are in contact with each other and connected by welding.

9. 2. The secondary battery according to claim 1, wherein the electrode terminal has a second recess disposed on a side facing the electrode assembly, the terminal connection portion has a second protrusion disposed on a side facing the electrode terminal, and the second protrusion and the second recess abut against each other and are connected by welding.

10. 2. The secondary battery according to claim 1, wherein the terminal connection portion and the main body portion are separately formed, and the thickness of the terminal connection portion is greater than the thickness of the main body portion.

11. 11. The secondary battery according to claim 10, wherein the terminal connection portion and the main body portion are connected by welding, and the welding connection strength is greater than 50N.

12. The secondary battery according to claim 11 , wherein a weld mark is formed between the terminal connection portion and the main body portion, the weld mark has a ring structure, and the weld mark has at least two turns.

13. 2. The secondary battery of claim 1, wherein the main body portion includes a support portion arranged in an annular shape, the terminal connection portion is located within a central region of the support portion, the deformable portion includes a weakened portion extending from the support portion toward the terminal connection portion, and the terminal connection portion is connected to the main body portion via the weakened portion.

14. The secondary battery according to claim 13 , wherein the weakened portion includes a bending guide portion that guides the weakened portion so that the weakened portion bends.

15. The secondary battery according to claim 14 , wherein the bending guide portion includes a second curved portion, and the second curved portion is disposed on a side of the weakened portion closer to the support portion.

16. The secondary battery according to claim 14 , wherein the bending guide portion includes a fold line, and the fold line is disposed on a side of the weakened portion closer to the support portion.

17. 14. The secondary battery according to claim 13, wherein the main body portion further includes a plurality of electrode tab connection portions, the plurality of electrode tab connection portions extending from the support portion toward a center of the electrode assembly, and the plurality of electrode tab connection portions being spaced apart from the terminal connection portion.

18. The secondary battery according to claim 13 , wherein an orthogonal projection of the support portion is located outside the orthogonal projection of the explosion-proof area along the height direction of the secondary battery and does not overlap with the orthogonal projection of the explosion-proof area.

19. A battery assembly comprising the secondary battery according to any one of claims 1 to 18.

20. 20. An electronic device comprising the battery assembly of claim 19.

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