End cap assembly, battery, and energy storage device

Abstract

The application provides an end cover assembly, a battery and an energy storage device. The end cover assembly comprises a pole and a first connecting piece. The pole comprises a pole body, a first pole protrusion and a second pole protrusion. The first pole protrusion and the second pole protrusion are arranged on the outer side of the pole body. A first groove is formed between the first pole protrusion and the second pole protrusion. The first groove comprises a first position and a second position along the radial direction of the pole. The first position is located on the side away from the pole of the second position. The cross-sectional width of the first position along the height direction of the pole is smaller than the cross-sectional width of the second position along the height direction of the pole. The first connecting piece is partially arranged in the first groove and fills the first groove. The end cover assembly provided by the application solves the technical problem that the sealing ring is prone to mispositioning and compression amount is difficult to control in the prior art, thereby causing poor assembly strength and sealing performance of the end cover assembly, and affecting the safety performance and use reliability of the battery.

Description

Technical Field

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

[0002] Rechargeable batteries have advantages such as high energy density, high power density, high cycle life and long storage time, and are widely used in electric vehicles, mobile devices and other fields.

[0003] In existing battery end cap assemblies, sealing rings are typically used as a crucial sealing structure. However, after being fitted onto the terminal post, the sealing ring is prone to misalignment or tilting, resulting in poor sealing performance of the end cap assembly. Furthermore, controlling the compression of the sealing ring is difficult; insufficient compression will affect the sealing performance of the end cap assembly, while excessive compression will generate a large rebound force, causing the end cap to warp and deform, affecting the assembly strength and sealing performance of the end cap assembly, thus significantly impacting the battery's safety and reliability. Summary of the Invention

[0004] This application provides an end cap assembly to solve the technical problems in the prior art where the sealing ring is prone to misalignment and the compression amount is difficult to control, resulting in poor assembly strength and sealing performance of the end cap assembly, which affects the safety performance and reliability of the battery.

[0005] This application also provides a battery and an energy storage device.

[0006] To address the above problems, in a first aspect, this application provides an end cap assembly, comprising: a pole post and a first connector. The pole post includes a pole post body, a first pole post protrusion, and a second pole post protrusion. The first pole post protrusion and the second pole post protrusion are disposed on the outer side of the pole post body, and a first groove is formed between the first pole post protrusion and the second pole post protrusion. The first groove includes a first position and a second position along the radial direction of the pole post. The first position is located on the side of the second position away from the pole post. The cross-sectional width of the first position along the height direction of the pole post is smaller than the cross-sectional width of the second position along the height direction of the pole post. The first connector is partially disposed in the first groove and fills the first groove.

[0007] It is understood that the first groove includes a first position and a second position along the radial direction of the electrode post. The first position is located on the side of the second position away from the electrode post, and the cross-sectional width of the first position along the height direction of the electrode post is smaller than the cross-sectional width of the second position along the height direction of the electrode post. In other words, the first groove has at least two positions along the radial direction of the electrode post, such that the cross-sectional width of the outermost position along the height direction of the electrode post is smaller than the cross-sectional width of the innermost position along the height direction of the electrode post. The first connector portion is disposed within and fills the first groove. When the end cap is subjected to external forces or when the first connector expands or contracts due to thermal expansion and contraction during battery use, the structure of the first groove can prevent the electrode post and the first connector from separating, thereby ensuring the sealing performance and reliability of the end cap assembly.

[0008] In one possible implementation, the first position is the bottom wall of the first groove, and the second position is the opening of the first groove, extending outward along the radial direction of the pole post. The cross-sectional width of the first groove gradually increases along the height direction of the pole post. By setting the cross-sectional width of the first groove to gradually increase along the height direction of the pole post,

[0009] Understandably, by designing an inverted conical first groove that is wider at the inside and narrower at the outside, after the first connector is injection molded, the first connector portion is positioned within the first groove and fills the space between the groove opening and the bottom wall. When the end cap is subjected to external forces or when the first connector expands and contracts due to heat during battery use, the structure of the first groove can prevent the electrode and the first connector from separating, thereby ensuring the sealing performance and reliability of the end cap assembly. By designing the cross-sectional width of the first groove to gradually increase along the height direction of the electrode, and the sidewalls of the first and second electrode protrusions changing uniformly relative to the radial direction of the electrode, not only is the molding and processing of the first groove easier and reduces its processing difficulty, but it also facilitates the smooth flow of the first injection molding liquid into the first groove, improving injection molding efficiency and thus increasing the assembly efficiency of the end cap assembly.

[0010] In one possible implementation, the first pole post protrusion includes a first end and a second end, the first end being away from the pole post body, and the second end being connected to the pole post body, wherein the cross-sectional width of the first end along the pole post height direction is greater than the cross-sectional width of the second end along the pole post height direction.

[0011] Understandably, by designing an inverted conical first groove that is wider at the inside and narrower at the outside, after the first connector is injection molded, the first connector portion is positioned within the first groove and fills the space between the groove opening and the bottom wall. When the end cap is subjected to external forces or when the first connector expands and contracts due to heat during battery use, the structure of the first groove can prevent the electrode and the first connector from separating, thereby ensuring the sealing performance and reliability of the end cap assembly. By designing the cross-sectional width of the first groove to gradually increase along the height direction of the electrode, and the sidewalls of the first and second electrode protrusions changing uniformly relative to the radial direction of the electrode, not only is the molding and processing of the first groove easier and reduces its processing difficulty, but it also facilitates the smooth flow of the first injection molding liquid into the first groove, improving injection molding efficiency and thus increasing the assembly efficiency of the end cap assembly.

[0012] In one possible implementation, the extending directions of the first pole post protrusion and the second pole post protrusion intersect.

[0013] Understandably, by setting the extension directions of the first pole post protrusion and the second pole post protrusion to intersect, when the pole post is assembled with the first connector and the second connector, more space can be reserved for the side of the second pole post protrusion facing the third pole post protrusion. This not only makes it easier for the second connector to partially extend into the second groove and reduces the space occupied by the second connector in the height direction of the end cap assembly, but also allows more of the injection molding material of the first connector to fill the space between the second connector and the pole post, ensuring the insulation performance between the second connector and the pole post.

[0014] In one possible implementation, the first groove includes a first groove and a second groove that are connected to each other. The cross-sectional width of the first groove along the height direction of the pole post is smaller than the cross-sectional width of the second groove along the height direction of the pole post. The first position is located in the first groove, and the second position is located in the second groove.

[0015] It is understandable that by setting the first groove and the second groove, the structure of the first groove is approximately a T-shaped groove. After the first connector is injection molded, the first connector is partially set in the first groove and fills the first groove and the second groove. When the end cap is subjected to external force or the first connector expands and contracts due to heat during battery use, the T-shaped structure of the first groove can enhance the force between the first connector and the terminal in the radial direction of the terminal, better preventing the terminal and the first connector from separating from each other, thereby further ensuring the sealing performance and reliability of the end cap assembly.

[0016] In one possible implementation, the first connector is formed by filling a portion of the material of the first connector into the first groove and covering the outer surface of the pole post through an injection molding process.

[0017] Understandably, through the injection molding process, the injection liquid of the first connector can be fully flowed into and sealed into the first groove. Compared with the assembly process in the prior art, this not only eliminates the sealing ring structure in the prior art, increases the number of parts in the end cap assembly and improves assembly efficiency, but also allows the first connector to fit fully into the first groove, effectively improving the tightness of the assembly between the first connector and the terminal post, ensuring the assembly strength and sealing performance of the end cap assembly, and thus ensuring the safety performance and reliability of the battery.

[0018] In one possible implementation, the end cap assembly further includes a second connector, which is embedded in and spaced apart from the first connector, and is used to connect to the end cap.

[0019] Understandably, by setting a second connector, the connection stability between the pole and the end cap can be improved, preventing the pole from detaching from the end cap due to insufficient fixing force, which would affect the reliability of the end cap assembly.

[0020] In one possible implementation, the end cap assembly further includes an end cap, and the second connector includes a first connecting portion, a transition portion, and a second connecting portion. The first connecting portion and the second connecting portion are spaced apart. The transition portion is connected between the first connecting portion and the second connecting portion and has a bent structure. The first connecting portion and the transition portion are embedded in the first connector. Along the radial direction of the pole post, the end of the second connecting portion away from the transition portion protrudes relative to the first connector, and the end of the second connecting portion away from the transition portion is connected to the end cap.

[0021] Understandably, by setting up the second connector, on the one hand, the connection stability between the pole and the end cap can be improved, preventing the pole from detaching from the end cap due to insufficient fixing force, thus affecting the reliability of the end cap assembly. On the other hand, the first transition part connects between the first and second connecting parts and has a bent structure. The second connector can significantly lengthen the leakage path within the end cap assembly, ensuring the sealing performance of the end cap assembly.

[0022] In one possible implementation, the electrode post further includes a third electrode post protrusion, which is disposed on the outer side of the electrode post body. The third electrode post protrusion is disposed on the side of the second electrode post protrusion away from the first electrode post protrusion, and a second groove is formed between the third electrode post protrusion and the second electrode post protrusion, with at least a portion of the first connecting portion located in the second groove.

[0023] It is understandable that by setting the first connecting part to be at least partially located in the second groove, displacement of the second connecting member in the radial direction of the electrode post can be prevented, further enhancing the connection strength of the second connecting member, the first connecting member, and the electrode post, ensuring the assembly strength and sealing performance of the end cap assembly, and reducing the space occupied by the second connecting member in the height direction of the end cap assembly, which is beneficial to improving the volumetric energy density of the battery.

[0024] In one possible implementation, the end cap assembly further includes an insulating member, which is stacked with the end cap. The insulating member is sleeved on the pole post and spaced apart from the pole post by a first connector. The insulating member has a slot, and the end of the first connector away from the end cap has a retaining part that abuts against the slot.

[0025] Understandably, this can improve the ease of assembly of the end cap assembly and enhance the assembly strength between the first connector and the insulating component, thereby ensuring the assembly efficiency and reliability of the end cap assembly.

[0026] Secondly, this application provides a battery including at least one of the aforementioned end cap components.

[0027] Thirdly, this application provides an energy storage device including at least one of the aforementioned batteries.

[0028] This application embodiment eliminates the sealing ring structure, provides a groove structure on the electrode post, and tightly connects the first connector, electrode post, and second connector. The second connector is welded to the end cap, which can effectively improve the assembly strength and sealing performance of the end cap assembly, thereby ensuring the safety performance and reliability of the battery. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application or the background art will be described below.

[0030] Figure 1 This is a schematic diagram of the structure of an end cap assembly provided in an embodiment of this application;

[0031] Figure 2 yes Figure 1 An exploded view of the end cap assembly shown.

[0032] Figure 3 yes Figure 1 A schematic cross-sectional view of the end cap assembly shown.

[0033] Figure 4 yes Figure 1 A schematic diagram of the structure of the first connector in the end cap assembly shown;

[0034] Figure 5 yes Figure 1 A schematic diagram of the structure of the second connector in the end cap assembly shown;

[0035] Figure 6 yes Figure 1 A schematic diagram of the pole structure in the end cap assembly shown;

[0036] Figure 7 This is a schematic cross-sectional view of the pole post along the height of the pole post according to an embodiment of this application;

[0037] Figure 8 This is a cross-sectional schematic diagram of the pole post along the height of the pole post according to another embodiment of this application;

[0038] Figure 9 This is a cross-sectional schematic diagram of the pole post along the height of the pole post according to another embodiment of this application;

[0039] Figure 10 This is a schematic cross-sectional view of the pole post along the height of the pole post according to another embodiment of this application;

[0040] Figure 11 This is a schematic diagram of the structure of a battery provided in one embodiment of this application;

[0041] Figure 12 yes Figure 11 An exploded view of the battery shown.

[0042] Figure 13 This is a schematic diagram of the structure of an energy storage device provided in an embodiment of this application.

[0043] Figure label:

[0044] End cap assembly 100, pole post 10,

[0045] The pole body is 11, the first segment is 111, and the second segment is 112.

[0046] The first pole protrusion 12, the first protrusion 121, the first recess 122,

[0047] The second pole post has a protrusion 13, a blind hole 131, a first end 132, a second end 133, a second protrusion 134, and a second recess 135.

[0048] The third pole post protrudes 14, and the welded part is 141.

[0049] First groove 15, first slot 151, second slot 152

[0050] Second groove 16,

[0051] First connector 20, first body 21, extension 22, first through hole 23, retaining part 24.

[0052] Second connector 30, first connecting part 31, transition part 32, second connecting part 33, second through hole 34, notch 35.

[0053] End cap 40, end cap body 41, third through hole 42, fourth through hole 43, fifth through hole 44, first countersunk plate 46, reinforcing rib 47.

[0054] Insulating component 50, insulating component body 51, sixth through hole 52, seventh through hole 53, eighth through hole 54, second countersunk plate 56, slot 57.

[0055] Explosion-proof valve 60, explosion-proof valve body 61, explosion-proof valve protective plate 62,

[0056] Battery 200, cell 110, casing 120, adapter 130, protective film 140.

[0057] Energy storage device 300, casing 310. Detailed Implementation

[0058] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0059] The specific embodiments of this application will now be clearly described in conjunction with the accompanying drawings.

[0060] Embodiments of this application provide an end cap assembly, a battery, and an energy storage device. The battery includes an end cap assembly and a battery cell; the end cap assembly is electrically connected to the battery cell to bring out the battery electrodes. When the battery is a single cell, it can be a prismatic single cell. The battery can also be further applied to an energy storage device, which may include, but is not limited to, battery modules, battery packs, and battery systems.

[0061] Please see Figure 1 , Figure 2 and Figure 3 , Figure 1 This is a schematic diagram of the structure of the end cap assembly 100 provided in the embodiments of this application. Figure 2 yes Figure 1 An exploded view of the end cap assembly 100 shown. Figure 3 yes Figure 1 The diagram shows a cross-sectional view of the end cap assembly 100.

[0062] The end cap assembly 100 provided in this embodiment includes: a terminal post 10, a first connector 20, a second connector 30, an end cap 40, an insulator 50, and an explosion-proof valve 60. The end cap 40 and the insulator 50 are stacked, the terminal post 10 passes through the end cap 40 and the insulator 50 as an electrode lead of the battery, the terminal post 10 and the first connector 20 are spaced apart by the second connector 30, and the explosion-proof valve 60 is mounted on the end cap 40 and used for pressure relief protection of the battery.

[0063] Please see Figure 4 The first connector 20 is manufactured by injection molding. The first connector 20 is generally cylindrical and includes a first body 21 and an extension 22. The first body 21 and the extension 22 are connected and coaxially arranged. The first body 21 has a first through hole 23 and a retaining part 24. The first through hole 23 penetrates the first body 21 and allows the pole post 10 to pass through. The retaining part 24 is located at the end of the first body 21 away from the extension 22. The extension 22 is located on the periphery of the first body 21 and extends radially along the first body 21. The outer diameter of the extension 22 is larger than the outer diameter of the first body 21. The extension 22 has a first protrusion (not shown) on its inner wall surface. Multiple first protrusions are spaced apart along the end of the extension 22 closest to the first body 21. The first protrusions increase the contact area and connection effect between the first connector 20 and the second connector 30.

[0064] Please see Figure 5The second connector 30 is generally a disc-shaped cover structure, including a first connecting portion 31, a transition portion 32, and a second connecting portion 33. Along the axial direction of the second connector 30, the first connecting portion 31, the first transition portion 32, and the second connecting portion 33 are connected sequentially; that is, the first transition portion 32 connects between the first connecting portion 31 and the second connecting portion 33 and has a bent structure. The first connecting portion 31 is a circular plate, and it has a second through hole 34 and a notch 35. The second through hole 34 penetrates the first connecting portion 31 along the axial direction of the second connector 30, and is used for the pole post 10 to pass through. The notch 35 is provided along the inner peripheral wall of the first connecting portion 31, and is used to cooperate with the first protrusion of the first connector 20 to enhance the contact area and connection effect between the second connector 30 and the first connector 20. The first transition portion 32 is connected to the periphery of one surface of the first connecting portion 31 and is set at an angle to the first connecting portion 31. The second connecting portion 33 is an annular plate, located on the outer periphery of the end of the first transition portion 32 furthest from the first connecting portion 31, and its diameter is larger than that of the first connecting portion 31. Understandably, the first transition portion 32 is approximately cylindrical, with its opposite ends connected to the first connecting portion 31 and the second connecting portion 33, respectively. The outer diameter of the first connecting portion 31 is smaller than that of the second connecting portion 33. The second connecting member 30 is made of metal, specifically aluminum.

[0065] The end cap 40 is a plate, and its shape can be square, round, or other shapes. For example, the end cap 40 is a rectangular plate. The end cap 40 is made of metal; specifically, the second connector 30 is made of aluminum. The end cap 40 includes an end cap body 41 and a third through hole 42, a fourth through hole 43, and a fifth through hole 44 provided on the end cap body 41. The third through hole 42, the fourth through hole 43, and the fifth through hole 44 are arranged sequentially along the length of the end cap body 41. The third through hole 42 is used for the electrode post 10 to pass through, and the fourth through hole 43 is used for the battery to inject electrolyte. The fifth through hole 44 is used to connect the explosion-proof valve 60. The end cap body 41 has a first recessed platform 46 and a reinforcing rib 47. The first recessed platform 46 is located on the inner peripheral wall of the third through hole 42 and is used to support the second connector 30. The reinforcing rib 47 is arranged around the periphery of the end cap body 41. By setting the reinforcing rib 47 structure, the end cap 40 can be strengthened while reducing its thickness, thus meeting the requirements for battery lightweighting and improving battery energy density.

[0066] The insulating component 50 is a plate, and its shape can be square, circular, or other shapes, and the shape of the insulating component 50 is the same as that of the end cap 40. For example, the insulating component 50 is a rectangular plate. The insulating component 50 includes an insulating component body 51 and a sixth through hole 52, a seventh through hole 53, and an eighth through hole 54 disposed on the insulating component body 51. The sixth through hole 52, the seventh through hole 53, and the eighth through hole 54 are arranged sequentially along the length of the insulating component body 51. The sixth through hole 52 is used for the pole post 10 to pass through, the seventh through hole 53 is used to connect to the fourth through hole 43, and the eighth through hole 54 is used to connect to the fifth through hole 44. The insulating component body 51 is provided with a second countersunk platform 56 and a notch 35. The second countersunk platform 56 is disposed on the inner peripheral wall of the sixth through hole 52, and the second countersunk platform 56 is used to receive the second connecting component 30. The notch 35 is provided along the inner peripheral wall of the second recessed platform 56, and the through hole is further provided with the notch 35 on the second recessed platform 56, so that the insulating body 51 can have a certain deformation space at the third through hole 42, thereby improving the assembly convenience of the end cap assembly 100.

[0067] The explosion-proof valve 60 includes an explosion-proof valve body 61 and an explosion-proof valve protection plate 62. The explosion-proof valve body 61 and the explosion-proof valve protection plate 62 are stacked together. The explosion-proof valve protection plate 62 is used to prevent the explosion-proof valve body 61 from being disturbed by the external environment.

[0068] Please see Figure 6 The electrode post 10 includes an electrode post body 11, a first electrode post protrusion 12, a second electrode post protrusion 13, and a third electrode post protrusion 14. The electrode post body 11 includes a first segment 111 and a second segment 112, which are sequentially connected and coaxially arranged along the axial direction of the electrode post body 11. The outer diameter of the first segment 111 is larger than the outer diameter of the second segment 112. The first electrode post protrusion 12, the second electrode post protrusion 13, and the third electrode post protrusion 14 are sequentially coaxially arranged and spaced apart along the axial direction of the electrode post body 11. The first electrode post protrusion 12 and the second electrode post protrusion 13 are located on the outer surface of the first segment 111, and the third electrode post protrusion 14 is located on the outer surface of the second segment 112. The outer diameter of the second electrode post protrusion 13 is less than or equal to the outer diameter of the first electrode post protrusion 12, and the outer diameter of the second electrode post protrusion 13 is greater than or equal to the outer diameter of the third electrode post protrusion 14. Specifically, the outer diameter of the second pole post protrusion 13 is smaller than that of the first pole post protrusion 12, and the outer diameter of the second pole post protrusion 13 is larger than that of the third pole post protrusion 14. The second pole post protrusion 13 is also provided with a blind hole 131, which is located on the outer side of the second pole post protrusion 13 and recessed towards the axis of the pole post body 11. The third pole post protrusion 14 is also provided with a welding part 141, which is located at the end of the third pole post protrusion 14 away from the second pole post protrusion 13. By providing the welding part 141, it is convenient for the welding fixture to fix the pole post 10, reducing the impact force on the pole post 10 during welding, thus affecting the structural reliability of the pole post 10 and the assembly strength of the end cap assembly 100.

[0069] A first groove 15 is formed between the first pole post protrusion 12 and the second pole post protrusion 13, and a second groove 16 is formed between the second pole post protrusion 13 and the third pole post protrusion 14. The first groove 15 includes a first position and a second position along the radial direction of the pole post 10. The first position is located on the side of the second position away from the pole post 10, and the cross-sectional width of the first position along the height direction of the pole post 10 is smaller than the cross-sectional width of the second position along the height direction of the pole post 10. That is, the first groove 15 has at least two positions along the radial direction of the pole post 10, such that the cross-sectional width of the outermost position along the height direction of the pole post 10 is smaller than the cross-sectional width of the innermost position along the height direction of the pole post 10. The side closer to the axis of the pole post 10 is called "inner," and the side farther from the axis of the pole post 10 is called "outer." The first groove 15 also has at least two positions along the radial direction of the pole post 10, such that the cross-sectional width of the outermost position along the height direction of the pole post 10 is smaller than the cross-sectional width of the innermost position along the height direction of the pole post 10. The structure of the second groove 16 can be the same as or different from the structure of the second groove 16.

[0070] The maximum cross-sectional height of the second groove 16 along the height direction of the pole post 10 is greater than or equal to the maximum cross-sectional height of the first groove 15 along the height direction of the pole post 10. In the embodiments of this application, the maximum cross-sectional height of the second groove 16 along the height direction of the pole post 10 is greater than the maximum cross-sectional height of the first groove 15 along the height direction of the pole post 10.

[0071] During the assembly of the end cap assembly 100, for example, the pole post 10 and the second connector 30 are placed in the injection mold and fixed, and the first connector 20 is injection molded. The injection liquid can not only flow into and seal the gap between the pole post 10 and the second connector 30, but also, including but not limited to, seal the first groove 15, the second groove 16, the notch 35 on the second connector 30, and the blind hole 131 on the protrusion 13 of the second pole post. After injection molding, one end of the first connector 20 forms a retaining part 24. The first connector 20, the pole post 10, and the second connector 30 simultaneously abut against and cover the outer side of the pole post 10, and the first connector 20, the pole post 10, and the second connector 30 are tightly fitted together. After the first connector 20 is assembled with the pole post 10 and the second connector 30, the second connector 30 is welded to the end cap 40 to achieve assembly with the end cap 40, and the retaining part 24 abuts against the slot 57 on the insulating part 50 to achieve assembly with the insulating part 50, thereby completing the assembly of the end cap assembly 100.

[0072] After the end cap assembly 100 is assembled, the first connector 20 fills the gap between the terminal post 10 and the second connector 30, providing positioning and fixing for the terminal post 10 and the second connector 30, while ensuring the insulation performance between the terminal post 10 and the end cap 40. The first connector 20 is partially disposed within the first groove 15 and the second groove 16, and fills both grooves completely. When the end cap 40 is subjected to external forces or when the first connector 20 expands or contracts due to heat during battery use, the structure of the first groove 15 and the second groove 16 can prevent the terminal post 10 and the first connector 20 from separating, thereby ensuring the sealing performance and reliability of the end cap assembly 100.

[0073] After the end cap assembly 100 is assembled, the material of the first connector 20 seals and fills the notch 35 of the second connector 30. By providing the notch 35 on the second connector 30, the contact area between the first connector 20 and the second connector 30 can be increased, thereby further enhancing the connection strength between the second connector 30 and the first connector 20, ensuring the assembly strength and reliability of the end cap assembly 100. In addition, the notch 35 can also reduce the resistance of the injection molding liquid of the first connector 20 flowing down to the gap between the first connector 20 and the pole post 10, improving the injection molding efficiency of the first connector 20, thereby improving the assembly efficiency of the end cap assembly 100. The material of the first connector 20 seals and fills the blind hole 131 of the second pole post protrusion 13. By providing the blind hole 131 on the outer side of the second pole post protrusion 13, the contact area between the pole post 10 and the first connector 20 can be increased, improving the connection strength between the pole post 10 and the first connector 20.

[0074] After the end cap assembly 100 is assembled, the first connecting portion 31 and the transition portion 32 of the second connecting member 30 are embedded in the first connecting member 20. Along the radial direction of the pole post 10, the end of the second connecting portion 33 away from the transition portion 32 protrudes relative to the first connecting member 20, and the end of the second connecting portion 33 away from the transition portion 32 is connected to the end cap 40. By providing the second connecting member 30, on the one hand, the connection stability between the pole post 10 and the end cap 40 can be improved, preventing the pole post 10 from detaching from the end cap 40 due to insufficient fixing force, thus affecting the reliability of the end cap assembly 100. On the other hand, the first transition portion 32 connects between the first connecting portion 31 and the second connecting portion 33 and has a bent structure. The second connecting member 30 can significantly lengthen the leakage path within the end cap assembly 100, ensuring the sealing performance of the end cap assembly 100. The length of the protrusion of the end of the second connecting portion 33 away from the transition portion 32 relative to the first connecting member 20 is greater than 1 mm. Preferably, the end of the second connecting portion 33 furthest from the transition portion 32 protrudes more than 1.5 mm from the first connecting member 20. By setting the exposed welding length of the second connecting portion 33, it is more convenient to weld the second connecting portion 33 to the end cap 40, ensuring the welding strength between the second connecting portion 33 and the end cap 40, thereby improving the reliability of the end cap assembly 100.

[0075] The gap between the transition portion 32 of the second connector 30 and the terminal post 10 is filled with the material of the first connector 20. Along the radial direction of the terminal post 10, the minimum gap between the transition portion and the second terminal post protrusion 13 is greater than 0.5mm, preventing any impact on the second terminal post protrusion 13 during welding of the second connector 30, thus ensuring the assembly strength and reliability of the end cap assembly 100. The minimum thickness of the first connector 20 covering the outer surface of the second connector 30 is greater than 0.5mm. By setting this minimum thickness, the second connector 30 can be protected from external interference, preventing short circuits caused by the second connector 30 communicating with other components during welding to the end cap 40 or during use of the end cap assembly 100, which would affect the battery's reliability.

[0076] The first connecting portion 31 of the second connector 30 is located in the second groove 16. By setting the first connecting portion 31 to be at least partially located in the second groove 16, displacement of the second connector 30 in the radial direction of the terminal post 10 can be prevented, further enhancing the connection strength of the second connector 30, the first connector 20, and the terminal post 10, ensuring the assembly strength and sealing performance of the end cap assembly 100. At the same time, it can also reduce the space occupied by the second connector 30 in the height direction of the end cap assembly 100, which is beneficial to improving the volumetric energy density of the battery.

[0077] After the end cap assembly 100 is assembled, the retaining portion 24 of the first connector 20 abuts against the retaining groove 57 of the insulating member 50. By providing the mutually cooperating retaining portion 24 and retaining groove 57, the assembly strength of the end cap assembly 100 and the first connector 20 and the insulating member 50 can be improved, thereby ensuring the assembly efficiency and reliability of the end cap assembly 100. The first recess 46 of the end cap 40 receives the second connecting portion 33 of the second connector 30. The depth of the first recess 46 is greater than or equal to the thickness of the second connecting portion 33. Specifically, the depth of the first recess 46 is equal to the thickness of the second connector 30. By providing the first recess 46 on the end cap 40, while ensuring the structural strength of the end cap 40, it is not only beneficial to weld the end cap 40 and the second connecting portion 33 on the same plane, improving the welding convenience and connection strength of the end cap 40 and the second connector 30, but also reducing the space occupied by the second connector 30 on the end cap assembly 100.

[0078] The specific construction of the pole post 10 will be described below through several different embodiments.

[0079] First embodiment

[0080] Please see Figure 7 , Figure 7 This is a cross-sectional view of the pole post 10 along its height direction (CC) according to the first embodiment of this application. A first groove 15 is formed between the first pole post protrusion 12 and the second pole post protrusion 13, and a second groove 16 is formed between the second pole post protrusion 13 and the third pole post protrusion 14. The first groove 15 includes a first position and a second position along the radial direction of the pole post 10. The first position is located on the side of the second position away from the pole post 10, and the cross-sectional width D1 of the first position along the height direction of the pole post 10 is smaller than the cross-sectional width D2 of the second position along the height direction of the pole post 10.

[0081] The first position is the bottom wall of the first groove 15, and the second position is the opening of the first groove 15. That is, the cross-sectional width of the opening along the height direction of the pole post 10 is D1, and the cross-sectional width of the bottom wall along the height direction of the pole post 10 is D2, where D1 is less than D2. Moving outward along the radial direction of the pole post 10, the cross-sectional width of the first groove 15 gradually increases along the height direction of the pole post 10. By setting an inverted conical first groove 15 that is larger inside and smaller outside, after the first connector 20 is injection molded, the first connector 20 is partially disposed within the first groove 15 and fills the space between the opening and the bottom wall. When the end cap 40 is subjected to external forces or when the first connector 20 expands and contracts due to heat during battery use, the structure of the first groove 15 can prevent the pole post 10 and the first connector 20 from separating, thereby ensuring the sealing performance and reliability of the end cap assembly 100. By setting the cross-sectional width of the first groove 15 to gradually increase along the height direction of the pole post 10, and the sidewalls of the first pole post protrusion 12 and the second pole post protrusion 13 to change uniformly in the radial direction relative to the pole post 10, it is not only beneficial to the molding and processing of the first groove 15 and reduces the processing difficulty of the first groove 15, but also beneficial to the smooth flow of the first injection molding liquid into the first groove 15, improving the injection molding efficiency, thereby improving the assembly efficiency of the end cap assembly 100.

[0082] The included angle α between the bottom wall and the side wall of the first groove 15 is in the range of 5 ≤ α ≤ 60°. When the included angle between the bottom wall and the side wall of the first groove 15 is too small, the processing and forming of the first groove 15 is more difficult, and it is more difficult for the injection molding liquid of the first connector 20 to completely fill the position, affecting the assembly efficiency and tightness of the fit. When the included angle between the bottom wall and the side wall of the first groove 15 is too large, the limiting effect of the first groove 15 on the first connector 20 is poor. When the end cap 40 is subjected to external force or the first connector 20 expands and contracts due to heat during battery use, the assembly strength between the terminal post 10 and the first connector 20 cannot be well guaranteed, thereby failing to guarantee the sealing performance and reliability of the end cap assembly 100.

[0083] The first pole post protrusion 12 and the second pole post protrusion 13 are disposed on the outer side of the first section 111 of the pole post body 11. The side wall of the first pole post protrusion 12 is connected to the end face of the pole post body 11 away from the third pole post protrusion 14. The cross-sectional width of the end of the first section 111 away from the third pole post protrusion 14 along the radial direction of the pole post 10 is greater than or equal to the cross-sectional width of the first pole post protrusion 12 along the radial direction of the pole post 10. By connecting the side wall of the first pole post protrusion 12 to the end face of the pole post body 11 away from the third pole post protrusion 14, the cross-sectional width of the first pole post protrusion 12 along the height direction of the pole post 10 can be increased, thereby increasing the structural strength and flow area of ​​the first pole post protrusion 12, thus ensuring the safety performance and reliability of the end cap assembly 100.

[0084] The second pole post protrusion 13 includes a first end 132 and a second end 133. The first end 132 is away from the pole post body 11, and the second end 133 is connected to the pole post body 11. The cross-sectional width of the first end 132 along the height direction of the pole post 10 is D3, and the cross-sectional width of the second end 133 along the height direction of the pole post 10 is D4, where D3 is greater than D4. That is, the surface of the second pole post protrusion 13 facing the first pole post protrusion 12 is inclined relative to the surface of the second pole post protrusion 13 away from the first pole post protrusion 12.

[0085] The second groove 16 has the same structure as the first groove 15. The maximum cross-sectional height of the second groove 16 along the height direction of the electrode post 10 is greater than that of the first groove 15 along the height direction of the electrode post 10. By setting the maximum cross-sectional height of the second groove 16 along the height direction of the electrode post 10 to be greater than that of the first groove 15 along the height direction of the electrode post 10, when the electrode post 10 is assembled with the second connector 30, it is beneficial that the first connecting portion 31 of the second connector 30 is at least partially located in the second groove 16, preventing the second connector 30 from shifting in the radial direction of the electrode post 10, further enhancing the connection strength of the second connector 30, the first connector 20, and the electrode post 10, ensuring the assembly strength and sealing performance of the end cap assembly 100, and also reducing the space occupied by the second connector 30 in the height direction of the end cap assembly 100, which is beneficial to improving the volumetric energy density of the battery.

[0086] Second embodiment

[0087] Please see Figure 8 , Figure 8 This is a cross-sectional view of the pole post 10 along the height direction (CC) of the pole post 10 in the second embodiment of this application.

[0088] In this embodiment, the contents that are the same as those in the first embodiment will not be repeated. The difference between the first embodiment and the first embodiment is that the structure of the first pole post protrusion 12 and the second pole post protrusion 13 are different.

[0089] In this embodiment, the extension directions of the first pole post protrusion 12 and the second pole post protrusion 13 intersect. That is, the first pole post protrusion 12 bends toward the second pole post protrusion 13, and in the radial direction of the pole post 10, the cross-sectional width of the second pole post protrusion 13 along the height direction of the pole post 10 is the same or similar. By setting the extension directions of the first pole post protrusion 12 and the second pole post protrusion 13 to intersect, when the pole post 10 is assembled with the first connector 20 and the second connector 30, more space can be reserved on the side of the second pole post protrusion 13 facing the third pole post protrusion 14. This not only makes it easier for the second connector 30 to partially extend into the second groove 16, reducing the space occupied by the second connector 30 in the height direction of the end cap assembly 100, but also allows more injection molding material of the first connector 20 to fill the space between the second connector 30 and the pole post 10, ensuring the insulation performance between the second connector 30 and the pole post 10.

[0090] The cross-sectional width of the first segment 111 at the end furthest from the third pole post protrusion 14 along the radial direction of the pole post 10 is at least partially smaller than the cross-sectional width of the first pole post protrusion 12 along the radial direction of the pole post 10. That is, the end face of the first segment 111 furthest from the third pole post protrusion 14 is not on the same plane as the end face of the first pole post protrusion 12 furthest from the second pole post protrusion 13. When assembled with the first connector 20, the gap between the first pole post protrusion 12 and the first segment 111 can be further filled with the material of the first connector 20, increasing the contact area between the first connector 20 and the pole post 10, and improving the structural strength and reliability of the end cap assembly 100.

[0091] Third embodiment

[0092] Please see Figure 9 , Figure 9 This is a cross-sectional view of the pole post 10 along the height direction (CC) of the pole post 10 in the third embodiment of this application.

[0093] In this embodiment, the contents that are the same as those in the first embodiment will not be repeated. The difference between this embodiment and the first embodiment is that the structure of the first groove 15 is different.

[0094] The first groove 15 includes a first groove 151 and a second groove 152, which are interconnected. The opening of the first groove 151 is the opening of the first groove 15, and the bottom wall of the second groove 152 is the bottom wall of the first groove 15. The cross-sectional width of the first groove 151 along the height direction of the pole post 10 is smaller than the cross-sectional width of the second groove 152 along the height direction of the pole post 10. A first position is located in the first groove 151, and a second position is located in the second groove 152. The cross-sectional width D1 of the first position along the height direction of the pole post 10 is smaller than the cross-sectional width D2 of the second position along the height direction of the pole post 10.

[0095] In the radial direction of the pole post 10, the cross-sectional width of the first groove 151 along the height direction of the pole post 10 may be the same or different, and the cross-sectional width of the second groove 152 along the height direction of the pole post 10 may be the same or different, but the cross-sectional width of the first groove 151 along the height direction of the pole post 10 is always smaller than the cross-sectional width of the second groove 152 along the height direction of the pole post 10. For example, in the radial direction of the pole post 10, the cross-sectional width of the first groove 151 along the height direction of the pole post 10 is the same, and the cross-sectional width of the second groove 152 along the height direction of the pole post 10 is the same. By setting the first groove 151 and the second groove 152, the structure of the first groove 15 is approximately a T-shaped groove. After the first connector 20 is injection molded, the first connector 20 is partially set in the first groove 15 and fills the first groove 151 and the second groove 152. When the end cap 40 is subjected to external force or the first connector 20 expands and contracts due to heat during battery use, the T-shaped structure of the first groove 15 can enhance the force between the first connector 20 and the terminal post 10 in the radial direction of the terminal post 10, better preventing the terminal post 10 and the first connector 20 from separating from each other, thereby further ensuring the sealing performance and reliability of the end cap assembly 100.

[0096] Fourth embodiment

[0097] Please see Figure 10 , Figure 10 This is a cross-sectional view of the pole post 10 along the height direction (CC) of the pole post 10 in the fourth embodiment of this application.

[0098] In this embodiment, the contents that are the same as those in the first embodiment will not be repeated. The difference between this embodiment and the first embodiment is that the structure of the first groove 15 is different.

[0099] The first pole post protrusion 12 includes a plurality of first protrusions 121 and a plurality of first recesses 122, with adjacent first protrusions 121 connected by at least one first recess 122. The second pole post protrusion 13 includes a plurality of second protrusions 134 and a plurality of second recesses 135, with adjacent second protrusions 134 connected by at least one second recess 135. Along the height direction of the pole post 10, the first protrusions 121 and second protrusions 134 may be arranged opposite each other, or the first protrusions 121 and second recesses 135 may be arranged opposite each other, or the first protrusions 121 and second recesses 135 and second protrusions 134 may be arranged opposite each other. For example, along the height direction of the pole post 10, the first protrusions 121 and second protrusions 134 are arranged opposite each other.

[0100] The first protrusion 121 and the second protrusion 134 constitute a first position, and the first recess 122 and the second recess 135 constitute a second position. The first position is located on the side of the second position away from the pole post 10, and the cross-sectional width D1 of the first position along the height direction of the pole post 10 is smaller than the cross-sectional width D2 of the second position along the height direction of the pole post 10. Through this convex-concave fit, after the first connector 20 is injection molded, there are more mating parts and a larger contact area between the first connector 20 and the pole post 10, which effectively improves the connection strength between the first connector 20 and the pole post 10, thereby ensuring the sealing performance and reliability of the end cap assembly 100. Through the opposing arrangement of the protrusions, a smaller gap can be formed between the first pole post protrusion 12 and the second pole post protrusion 13, thereby further enhancing the radial force between the first connector 20 and the pole post 10, better preventing the pole post 10 and the first connector 20 from separating, thus further ensuring the sealing performance and reliability of the end cap assembly 100.

[0101] Please see Figure 11 and Figure 12 , Figure 11 This is a schematic diagram of the structure of the battery 200 provided in the embodiment of this application. Figure 12 yes Figure 11 An exploded view of battery 200 is shown.

[0102] The battery 200 provided in this application embodiment includes: end cap assembly 100, battery cell 110, adapter plate 130 and housing 120. A protective film 140 may also be attached to the surface of the housing 120. The battery cell 110 is located inside the housing 120 and can be protected from interference from the external environment under the protection of the housing 120 and the protective film 140. The battery cell 110 and the end cap assembly 100 are connected through the adapter plate 130.

[0103] In this embodiment, battery 200 is a secondary battery. Examples include nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid (or lead-acid) batteries, lithium-ion batteries, and polymer lithium-ion batteries. In other embodiments, battery 200 can also be a primary lithium-ion battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery. Battery 200 can be a cuboid, a cylinder, or other shapes. In this embodiment, battery 200 is a cuboid.

[0104] It is understood that the battery 200 described in the embodiments of this application is merely one form of the battery 200 used in the end cap assembly, and should not be construed as a limitation on the battery 200 provided in this application, nor should it be construed as a limitation on the end cap assembly 100 provided in various embodiments of this application.

[0105] Please see Figure 13 , Figure 13This is a schematic diagram of the structure of the energy storage device 300 provided in this application embodiment. The energy storage device 300 provided in this application embodiment includes: a housing 310 and multiple batteries 200. The multiple batteries 200 are electrically connected and all are located inside the housing 310, which protects them from external environmental interference. In this embodiment, one energy storage device 300 includes multiple batteries 200. The multiple batteries 200 are arranged at intervals. The multiple batteries 200 can be connected in series, in parallel, or in a mixed series and parallel connection to achieve a larger capacity and power.

[0106] It is understood that the energy storage device 300 described in the embodiments of this application is merely one form of the energy storage device 300 used in the battery 200, and should not be construed as a limitation on the energy storage device 300 provided in the embodiments of this application, nor should it be construed as a limitation on the battery 200 provided in the various embodiments of this application.

[0107] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0108] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0109] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0110] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0111] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0112] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. An end cap assembly, characterized in that, include: The device includes an end cap, an electrode post, a first connector, and a second connector. The electrode post includes an electrode post body, a first electrode post protrusion, a second electrode post protrusion, and a third electrode post protrusion. The first electrode post protrusion and the second electrode post protrusion are disposed on the outer side of the electrode post body. A first groove is formed between the first electrode post protrusion and the second electrode post protrusion. The first groove includes a first position and a second position along the radial direction of the electrode post. The first position is located on the side of the second position away from the electrode post. The cross-sectional width of the first position along the height direction of the electrode post is smaller than the cross-sectional width of the second position along the height direction of the electrode post. The first connector is partially disposed in the first groove and fills the first groove. The second connector is embedded in the first connector and spaced apart from the first connector. The second connector includes a first connecting part, a transition part and a second connecting part. The first connecting part and the second connecting part are spaced apart. The transition part is connected between the first connecting part and the second connecting part and has a bent structure. The first connecting part and the transition part are embedded in the first connector. Along the radial direction of the pole post, the end of the second connecting part away from the transition part protrudes relative to the first connector. The end of the second connecting part away from the transition part is connected to the end cap. The third pole post protrusion is disposed on the outer side of the pole post body. The third pole post protrusion is disposed on the side of the second pole post protrusion away from the first pole post protrusion. A second groove is formed between the third pole post protrusion and the second pole post protrusion. At least a portion of the first connecting portion is located in the second groove.

2. The end cap assembly according to claim 1, characterized in that, The first position is the opening of the first groove, and the second position is the bottom wall of the first groove. Along the radial direction of the pole post, the cross-sectional width of the first groove gradually increases along the height direction of the pole post.

3. The end cap assembly according to claim 2, characterized in that, The first pole post protrusion includes a first end and a second end. The first end is away from the pole post body, and the second end is connected to the pole post body. The cross-sectional width of the first end along the pole post height direction is greater than the cross-sectional width of the second end along the pole post height direction.

4. The end cap assembly according to claim 2, characterized in that, The extension directions of the first pole post protrusion and the second pole post protrusion intersect.

5. The end cap assembly according to claim 1, characterized in that, The first groove includes a first groove and a second groove that are connected to each other. The cross-sectional width of the first groove along the height direction of the pole post is smaller than the cross-sectional width of the second groove along the height direction of the pole post. The first position is located in the first groove, and the second position is located in the second groove.

6. The end cap assembly according to claim 1, characterized in that, The first connector is formed by filling a portion of the material of the first connector into the first groove and covering the outer surface of the pole post through an injection molding process.

7. The end cap assembly according to claim 1, characterized in that, The end cap assembly further includes an insulating component, which is stacked with the end cap. The insulating component is sleeved on the pole post and spaced apart from the pole post by the first connector. The insulating component has a slot, and the end of the first connector away from the end cap has a retaining part, which abuts against the slot.

8. A battery, characterized in that, Includes the end cap assembly as described in any one of claims 1-7.

9. An energy storage device, characterized in that, It includes at least one battery as described in claim 8.

Images