End cap assembly, battery cell, energy storage device and electrical equipment

Abstract

This application discloses an end cap assembly, a battery cell, an energy storage device, and an electrical device. The end cap assembly includes an end cap, an upper plastic layer, and a terminal post. The end cap has a through hole for the terminal post. The upper plastic layer has a first mounting through hole on its main body and a second mounting through hole on its protruding portion. The inner wall surface of the second mounting through hole includes a first anti-rotation surface. The outer peripheral surface of the main body includes a positioning surface, which is a plane. The upper plastic layer is disposed on the end cap, the protruding portion passes through the terminal post through hole, and the main body is disposed on the top surface of the end cap. The outer peripheral surface of the first column of the terminal post includes a second anti-rotation surface. The terminal post is mounted on the upper plastic layer, the protrusion of the terminal post passes through the first mounting through hole, and the first column passes through the second mounting through hole. The second anti-rotation surface is in contact with the first anti-rotation surface, and the second anti-rotation surface and the first anti-rotation surface are mutually anti-positioned along the circumferential direction of the terminal post. The protrusion of the terminal post passes through the first mounting through hole. The end cap assembly provided by this application can prevent the terminal post from twisting when subjected to external force, thereby improving the sealing performance of the terminal post.

Description

Technical Field

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

[0002] A secondary battery, also known as a rechargeable battery or accumulator, is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. In a battery module, the terminals of adjacent battery cells are usually electrically connected by a connector, thus achieving series and parallel connection of the battery cells. When the connector is poorly welded to the terminal, it needs to be removed. However, removing the connector can easily cause the terminal to twist, which can affect the sealing of the terminal and the stability of the electrical connection between the terminal and the battery cell. Utility Model Content

[0003] This application provides an end cap assembly, a battery cell, an energy storage device, and an electrical device, which can reduce or even avoid the torsion of the terminal when subjected to external force, prevent terminal seal failure, and improve the electrical connection stability between the terminal and the battery cell.

[0004] In a first aspect, this application provides an end cap assembly. The end cap assembly includes an end cap, an upper plastic part, and an electrode post. The end cap has an electrode post through hole that penetrates the top and bottom surfaces of the end cap. The upper plastic part includes a body and a protrusion. The body has a first mounting through hole, and the protrusion has a second mounting through hole. The protrusion is connected to the body along the thickness direction of the end cap assembly, and the second mounting through hole communicates with the first mounting through hole. The inner wall surface of the second mounting through hole includes a first anti-rotation surface. The outer peripheral surface of the body includes a positioning surface, which is a plane. The upper plastic part is disposed on the end cap, the protrusion passes through the electrode post through hole, and the body is disposed on the top surface of the end cap.

[0005] The electrode post includes a first column and a protrusion, the first column and the protrusion being connected along the thickness direction of the end cap assembly. The outer peripheral surface of the first column includes a second anti-rotation surface. The electrode post is mounted on the upper plastic, the protrusion passing through the first mounting through hole, the first column passing through the second mounting through hole, the second anti-rotation surface contacting the first anti-rotation surface, and the second anti-rotation surface and the first anti-rotation surface mutually stopping each other along the circumferential direction of the electrode post.

[0006] In one possible implementation, there are two positioning surfaces, which are parallel and opposite to each other. The outer peripheral surface of the body also includes two connecting surfaces, both of which are arc surfaces, opposite to each other, and connected between the two positioning surfaces.

[0007] In one possible implementation, both the first anti-rotation surface and the second anti-rotation surface are planar, and the first anti-rotation surface and the second anti-rotation surface are arranged parallel to each other.

[0008] In one possible implementation, there are multiple first anti-rotation surfaces, which are sequentially arranged around the inner wall of the second mounting through hole and connected end-to-end. There are also multiple second anti-rotation surfaces, which are sequentially arranged around the outer periphery of the first column and connected end-to-end. Each second anti-rotation surface corresponds one-to-one with a corresponding first anti-rotation surface, and each second anti-rotation surface is parallel to and in contact with its corresponding first anti-rotation surface.

[0009] In one possible implementation, the inner wall of the second mounting through hole has a regular hexagonal outline, the outer peripheral surface of the first column has a regular hexagonal outline, and the outline of the outer peripheral surface of the first column is consistent with the outline of the inner wall of the second mounting through hole.

[0010] In one possible implementation, the inner wall surface of the through hole of the pole post includes a third anti-rotation surface, which is a plane. The outer peripheral surface of the protrusion includes a fourth anti-rotation surface, which is a plane, and the fourth anti-rotation surface is parallel to and in contact with the third anti-rotation surface.

[0011] In one possible implementation, there are multiple third anti-rotation surfaces, which are sequentially arranged around the inner wall of the through hole of the pole post and connected end to end; there are also multiple fourth anti-rotation surfaces, which are sequentially arranged around the outer periphery of the protrusion and connected end to end. Each of the multiple fourth anti-rotation surfaces corresponds one-to-one with a corresponding third anti-rotation surface, and each fourth anti-rotation surface is parallel to and in contact with its corresponding third anti-rotation surface.

[0012] In one possible implementation, the end cap assembly further includes a lower plastic core, which includes an electrode post hole extending through the lower plastic core along its thickness direction. The inner wall surface of the electrode post hole includes a fifth anti-rotation surface, which is planar. The lower plastic core is disposed at the bottom of the end cap and fixedly connected to it, with the electrode post hole and the electrode post through-hole facing each other. The protrusion passes through the electrode post through-hole and the electrode post hole, and the fourth anti-rotation surface is parallel to and opposite to the fifth anti-rotation surface.

[0013] In one possible implementation, the end cap assembly further includes a sealing ring fitted around the outer periphery of the protrusion and located within the pole hole, and the sealing ring sealing between the protrusion and the lower plastic.

[0014] Secondly, this application provides a battery cell, including a housing, an electrode assembly, a connector, and an end cap assembly. The housing has an opening and a receiving cavity, the receiving cavity communicating with the opening. The electrode assembly is disposed within the receiving cavity, the end cap assembly covers the opening and is fixedly connected to the housing; the connector is electrically connected between the terminal post and the electrode assembly.

[0015] In one possible implementation, the connector includes a first connecting portion and a second connecting portion, which are connected at an angle. The first connecting portion has a first connecting hole that extends through the first connecting portion along its thickness direction. The electrode post also includes a flange connected to the side of the first post facing away from the protrusion. The first connecting portion is located at the bottom of the end cap, the flange passes through the first connecting hole, and the flange contacts the inner wall of the first connecting hole; the second connecting portion is electrically connected to the electrode assembly.

[0016] In one possible implementation, the first connection portion is welded to the flange.

[0017] In one possible implementation, the surface of the first connecting portion facing the end cap is provided with a limiting groove, the limiting groove surrounding the outer periphery of the first connecting hole. The sidewall of the limiting groove includes a sixth anti-rotation surface, the sixth anti-rotation surface being a plane. The protrusion is at least partially located within the limiting groove, and a fourth anti-rotation surface located on the outer periphery of the protrusion is parallel to and in contact with the sixth anti-rotation surface.

[0018] Thirdly, this application provides an energy storage device, including an electrical connector and the battery cells, with at least two battery cells arranged side by side, and the electrical connector electrically connected between the terminals of two adjacent battery cells.

[0019] In one possible implementation, at least one edge of the electrical connector is flush with the positioning surface.

[0020] Fourthly, this application provides an electrical device, including the energy storage device, which is used to supply power to the electrical device.

[0021] In summary, the end cap assembly provided in this application, by providing a second anti-rotation surface on the electrode post and a first anti-rotation surface on the upper plastic that mates with the second anti-rotation surface, enables the second anti-rotation surface to prevent the electrode post from rotating relative to the upper plastic. This improves the connection stability between the electrode post and the upper plastic, increases the torque between them, and reduces or even prevents the electrode post from twisting relative to the upper plastic when subjected to external forces, thereby preventing electrode post seal failure. Furthermore, the end cap assembly provided in this application, by providing a positioning surface on the outer circumferential surface of the upper plastic, can also position the electrical connector, ensuring the connection angle and position of the electrical connector, thereby improving the connection yield between the electrical connector and the electrode post. Attached Figure Description

[0022] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is an application scenario diagram of the electrical equipment provided in the embodiments of this application;

[0024] Figure 2 This is a schematic diagram of the energy storage device provided in the embodiments of this application;

[0025] Figure 3 yes Figure 2 A schematic diagram of the structure of a single battery cell in the energy storage device shown.

[0026] Figure 4 yes Figure 3 The diagram shows the exploded structure of a single battery cell.

[0027] Figure 5 yes Figure 2 A partial structural diagram of a single battery cell is shown.

[0028] Figure 6 yes Figure 5 A partial exploded structural diagram of a single battery cell is shown.

[0029] Figure 7 yes Figure 5 The diagram shows a partial cross-sectional structure of a single battery cell along the AA direction.

[0030] Figure 8 yes Figure 6 A schematic diagram of the structure of the first electrode post in the shown battery cell;

[0031] Figure 9 yes Figure 8 The diagram shows the structure of the first pole at another angle;

[0032] Figure 10 yes Figure 6 The diagram shows the structure of the first upper plastic layer in the battery cell.

[0033] Figure 11 yes Figure 10 The diagram shows the structure of the first upper plastic piece from another angle.

[0034] Figure 12 yes Figure 6 A partial structural diagram of the end cap in the shown battery cell;

[0035] Figure 13 yes Figure 6 The diagram shows the structure of the lower plastic component in the battery cell.

[0036] Figure 14 yes Figure 6 A schematic diagram of the structure of the first connector in the battery cell shown;

[0037] Figure 15 yes Figure 5 The diagram shows a partial structural view of a single battery cell from another angle.

[0038] Reference numerals: Energy storage system 1000; Power conversion device 300; Wind power conversion device 310; First user load 320; Energy storage cabinet 330; Energy storage device 200; Battery cell 100; Electrical connector 210; First electrical connector 210a; Second electrical connector 210b; Third electrical connector 210c; First battery cell 100a; Second battery cell 100b; Third battery cell 100c; Fourth battery cell Single unit 100d; shell 50; receiving cavity 51; opening 52; end cap assembly 1; end cap 10; top surface 11; bottom surface 12; pole post through hole 13; first pole post through hole 13a; second pole post through hole 13b; first explosion-proof hole 14; first injection hole 15; third anti-rotation surface 131; upper plastic 20; first upper plastic 20a; second upper plastic 20b; through hole 201; body 21; first surface 211; second surface 212; second outer peripheral surface 2 13; Second inner circumferential surface 214; First mounting through hole 215; Positioning surface 2131; Connecting surface 2132; Protrusion 22; Second mounting through hole 221; Third inner circumferential surface 222; Third outer circumferential surface 223; First anti-rotation surface 224; Fourth anti-rotation surface 225; Limiting platform 216; Lower plastic 30; Electrode hole 31; First electrode hole 31a; Second electrode hole 31b; Fifth anti-rotation surface 311; Second explosion-proof hole 32; Second injection hole 33; Guide Flow hole 34; pole post 40; first pole post 40a; second pole post 40b; first column 41; protrusion 42; flange 43; first outer peripheral surface 411; second anti-rotation surface 412; limiting part 421; electrode assembly 60; connector 70; first connector 70a; second connector 70b; first connecting part 71; second connecting part 72; first connecting hole 711; limiting groove 712; sixth anti-rotation surface 713; explosion-proof valve 80; sealing ring 90. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0040] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve energy efficiency, it is necessary to store one form of energy in the same way or by converting it into another, and then release it in a specific energy form according to future application needs. As we all know, to achieve the grand goal of carbon neutrality, the main way to generate green electricity is to develop green energy sources such as photovoltaics and wind power to replace fossil fuels. Currently, the generation of green electricity generally relies on photovoltaics, wind power, and hydropower. However, wind and solar energy generally suffer from strong intermittency and large fluctuations, which can cause grid instability, insufficient electricity during peak demand periods, and excessive electricity during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar curtailment." Solving these problems requires energy storage. Energy storage involves converting electrical energy into other forms of energy through physical or chemical means and storing it. When needed, the stored energy is converted back into electrical energy and released. Simply put, energy storage is like a large "power bank". When there is sufficient solar and wind power, electrical energy is stored and the stored power is released when needed.

[0041] Taking electrochemical energy storage as an example, this solution provides an energy storage device. The energy storage device is equipped with a set of chemical batteries. It mainly uses the chemical elements in the chemical batteries as the energy storage medium. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. Simply put, the electrical energy generated by wind and solar energy is stored in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electricity is released for use, or transferred to places with a shortage of electricity for use.

[0042] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side energy storage. The corresponding types of energy storage devices include:

[0043] (1) Large energy storage containers applied in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, realize load matching of electrical energy in time and space, enhance the absorption capacity of renewable energy, and play a significant role in grid system backup, alleviating peak load power supply pressure and peak regulation and frequency regulation.

[0044] (2) Small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios (banks, shopping malls, etc.) and small household energy storage boxes used in home energy storage scenarios mainly operate under the "peak shaving and valley filling" mode. Since there are significant price differences in electricity prices at peak and valley times based on electricity demand, users with energy storage devices usually charge the energy storage cabinets / boxes during periods of low electricity prices and release the electricity from the energy storage devices during periods of high electricity prices to save on electricity costs. In addition, in remote areas and areas prone to natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices is equivalent to providing backup power for users and the power grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0045] Please see Figure 1 , Figure 1 This is an application scenario diagram of the electrical equipment provided in the embodiments of this application. The embodiments of this application take the home energy storage scenario in user-side energy storage as an example for illustration, and the energy storage device of this application is not limited to the home energy storage scenario.

[0046] This application provides a residential energy storage system 1000, which includes a power conversion device 300 (photovoltaic panel), a wind power conversion device 310 (windmill), a first user load 320 (base station), a second user load (not shown) (commercial / industrial side), and an energy storage device. The energy storage system 1000 also includes an energy storage cabinet 330, in which the energy storage device is installed for easy outdoor installation. Specifically, the power conversion device 300 can convert solar energy into electrical energy during periods of low electricity prices. The energy storage device stores this electrical energy and supplies it to the base station and commercial / industrial side during peak electricity prices, or provides power during grid outages / power interruptions. The wind power conversion device 310 (windmill) can convert wind energy into electrical energy. The energy storage device stores this electrical energy and supplies it to the base station and commercial / industrial side during peak electricity prices, or provides power during grid outages / power interruptions. The electrical energy can be transmitted via high-voltage cables.

[0047] Among them, energy storage cabinet 330 can be understood as electrical equipment. Energy storage devices can also be used in the form of energy storage containers, small and medium-sized energy storage cabinets, and small household energy storage boxes, etc., which contain energy storage devices. The aforementioned energy storage containers, small and medium-sized energy storage cabinets, and small household energy storage boxes, etc., which contain energy storage devices, can all be understood as electrical equipment.

[0048] It is understood that energy storage devices may include, but are not limited to, individual batteries, battery modules, battery packs, and battery systems. The actual application forms of the energy storage devices provided in this application embodiment may be, but are not limited to, the listed products, and may also be other application forms. This application embodiment does not strictly limit the application forms of energy storage devices.

[0049] In this embodiment, the energy storage device is a battery module, which includes multiple battery cells.

[0050] Please see Figure 2 , Figure 2 This is a schematic diagram of the structure of the energy storage device 200 provided in the embodiments of this application.

[0051] The energy storage device 200 includes multiple battery cells 100 and multiple electrical connectors 210. Each battery cell 100 includes two terminals 40. The two terminals 40 are designated as a first terminal 40a and a second terminal 40b. In this embodiment, the first terminal 40a is the positive terminal, and the second terminal 40b is the negative terminal. Current flows from the first terminal 40a into the cell of the battery cell 100 and then flows out from the second terminal 40b.

[0052] Multiple battery cells 100 are arranged side by side, and each adjacent pair of battery cells 100 is electrically connected by an electrical connector 210 to achieve a series-parallel connection of the multiple battery cells 100. For example, in this embodiment, the multiple battery cells 100 are connected in series. The first electrical connector 210a is connected between the second terminal 40b of the first battery cell 100a and the first terminal 40a of the second battery cell 100b; the second electrical connector 210b is connected between the second terminal 40b of the second battery cell 100b and the first terminal 40a of the third battery cell 100c; and the third electrical connector 210c is connected between the second terminal 40b of the third battery cell 100c and the first terminal 40a of the fourth battery cell 100d, thereby achieving the following connection: Figure 2 The four battery cells 100 shown are connected in series.

[0053] The electrical connector 210 and the pole post 40 are fixedly connected and electrically connected by welding.

[0054] It should be noted that when the welding between the electrical connector 210 and the terminal 40 is poor, or when the electrical connector 210 needs to be removed from the terminal 40 for other reasons, the electrical connector 210 will cause the terminal 40 to twist, which will affect the sealing of the terminal 40 and the stability of the electrical connection between the terminal 40 and the battery cell.

[0055] The energy storage device 200 provided in this application can reduce or even avoid the torsion of the terminal 40 when it is subjected to external force, thereby avoiding the failure of the terminal 40 seal and improving the electrical connection stability between the terminal 40 and the battery cell.

[0056] Please see Figure 3 and Figure 4 , Figure 3 yes Figure 2A schematic diagram of the structure of the battery cell 100 in the energy storage device 200 is shown. Figure 4 yes Figure 3 The diagram shows the exploded structure of the battery cell 100.

[0057] For ease of description, in this application, the length direction of the battery cell 100 is defined as the first direction, i.e., the X direction; the width direction of the battery cell 100 is defined as the second direction, i.e., the Y direction; and the height direction of the battery cell 100 is defined as the third direction, i.e., the Z direction. The X, Y, and Z directions are all perpendicular to each other.

[0058] The battery cell 100 includes a housing 50, an end cap assembly 1, an electrode assembly 60, an electrolyte, and connectors 70. The housing 50 has a receiving cavity 51 and an opening 52, the receiving cavity 51 communicating with the opening 52, and the opening 52 located on one side of the housing 50 in the height direction. The electrode assembly 60 and the electrolyte are located within the receiving cavity 51, and the electrode assembly 60 is immersed in the electrolyte. The electrode assembly 60 includes multiple electrode cores. The multiple electrode cores are arranged side-by-side along the width direction (Y direction) of the energy storage device 200. Each electrode core includes a positive tab and a negative tab (not shown). The end cap assembly 1 is mounted on the opening 52 side of the housing 50 and is fixedly connected to the housing 50 to close the receiving cavity 51. There are two connectors 70. The two connectors 70 are a first connector 70a and a second connector 70b. The first connector 70a is connected between the positive electrode tab and the first pole post 40a of the end cap assembly 1, and the second connector 70b is connected between the negative electrode tab and the second pole post 40b of the end cap assembly 1.

[0059] In this embodiment, the outer side of the electrode assembly 60 is also covered with an insulating film (not shown) to protect the electrode core and prevent it from being scratched. The insulating film covers the outer surface of the electrode assembly 60, and the sides of the insulating film are thermally bonded to the end cap assembly 1.

[0060] Please see Figure 5 and Figure 6 , Figure 5 yes Figure 2 A partial structural schematic diagram of the battery cell 100 shown. Figure 6 yes Figure 5 A partial exploded view of the battery cell 100 shown.

[0061] The end cap assembly 1 includes an end cap 10, an upper plastic 20, a lower plastic 30, an electrode post 40, and an explosion-proof valve 80. In this embodiment, the end cap 10 is a rectangular thin plate. In other embodiments, the end cap 10 can also be a circular plate, an elliptical plate, or an irregularly shaped plate. In this embodiment, the end cap 10 is a plain aluminum part. The end cap 10 includes a top surface 11 and a bottom surface 12. The top surface 11 and the bottom surface 12 are arranged opposite to each other along the Z direction. The end cap 10 is provided with an electrode post through hole 13, a first explosion-proof hole 14, and a first liquid injection hole 15. There are two electrode post through holes 13. The two electrode post through holes 13 are a first electrode post through hole 13a and a second electrode post through hole 13b. Along the length direction of the end cap 10, that is, along the X direction, the first electrode post through hole 13a, the first liquid injection hole 15, the first explosion-proof hole 14, and the second electrode post through hole 13b are arranged alternately in sequence. Furthermore, the first electrode through hole 13a, the first liquid injection hole 15, the first explosion-proof hole 14, and the second electrode through hole 13b all penetrate the top surface 11 and the bottom surface 12 along the Z direction.

[0062] There are two terminals 40, namely a first terminal 40a and a second terminal 40b. There are also two upper plastic inserts 20, namely a first upper plastic insert 20a and a second upper plastic insert 20b. The first terminal 40a passes through the first terminal through-hole 13a. The first upper plastic insert 20a is fitted around the outer periphery of the first terminal 40a and connects to both the first terminal 40a and the end cap 10. The first terminal 40a is insulated from the end cap 10 via the first upper plastic insert 20a. The second terminal 40b passes through the second terminal through-hole 13b. The second upper plastic insert 20b is fitted around the outer periphery of the second terminal 40b and connects to both the second terminal 40b and the end cap 10. The second terminal 40b is insulated from the end cap 10 via the second upper plastic insert 20b. In this embodiment, the first terminal 40a is the positive terminal 40, and the second terminal 40b is the negative terminal 40. In other embodiments, the first terminal 40a may also be a negative terminal 40, and the second terminal 40b may be a positive terminal 40.

[0063] An explosion-proof valve 80 is installed in the first explosion-proof hole 14 and fixedly connected to the end cap 10. For example, the explosion-proof valve 80 is welded to the inner wall of the first explosion-proof hole 14. When the pressure inside the energy storage device 200 becomes too high, the explosion-proof valve 80 will automatically open to release pressure, preventing the energy storage device 200 from exploding and improving the safety performance of the energy storage device 200.

[0064] The first injection port 15 is located between the explosion-proof valve 80 and the first terminal post 40a. During the electrolyte injection process of the energy storage device 200, electrolyte is injected into the battery cell 100 through the first injection port 15.

[0065] The lower plastic 30 is generally rectangular and thin. The lower plastic 30 is made of an insulating material. For example, the lower plastic 30 is made of plastic or rubber, or it may be made of other insulating materials. The lower plastic 30 is disposed at the bottom of the end cap 10 and is stacked with the end cap 10 along the Z-direction, and the lower plastic 30 is fixedly connected to the end cap 10. The lower plastic 30 serves to achieve insulation between the electrode assembly 60 and the end cap 10.

[0066] The following description uses the partial structure of end cap assembly 1 in the negative X-axis direction as an example.

[0067] Please see Figures 7 to 9 , Figure 7 yes Figure 5 The diagram shows a partial cross-sectional view of the battery cell 100 along the AA direction. Figure 8 yes Figure 6 The diagram shows the structure of the first terminal 40a in the battery cell 100. Figure 9 yes Figure 8 The diagram shows the structure of the first pole post 40a at another angle.

[0068] The first pole post 40a includes a first column 41, a protrusion 42, and a flange 43. The first column 41 is cylindrical in shape, but not circular. That is, the outer contour of the first column 41 is non-circular. The first column 41 includes a first outer peripheral surface 411. The first outer peripheral surface 411 includes a second anti-rotation surface 412. In this embodiment, the second anti-rotation surface 412 is planar. That is, the first outer peripheral surface 411 is at least partially planar. Exemplarily, there are multiple second anti-rotation surfaces 412. These multiple second anti-rotation surfaces 412 are sequentially arranged around the outer periphery of the first column 41 and connected end-to-end. It can be understood that the shape of the first column 41 along a cross-section parallel to the XY plane is polygonal. Exemplarily, there are six second anti-rotation surfaces 412, which are sequentially arranged around the outer periphery of the first column 41 and connected end-to-end. That is, the shape of the first column 41 along a cross-section parallel to the XY plane is hexagonal. Specifically, the first column 41 has a regular hexagonal shape along its cross section parallel to the XY plane, meaning that the first outer peripheral surface 411 is formed by connecting six planes end to end.

[0069] In this embodiment, an arc-shaped chamfer is provided between each two adjacent second anti-rotation surfaces 412 to improve the smoothness of the first outer peripheral surface 411.

[0070] In some embodiments, the shape of the first column 41 along the cross section parallel to the XY plane can also be a quadrilateral, pentagon, heptagon, octagon, etc.

[0071] In some embodiments, the first outer peripheral surface 411 may also be formed by connecting an arc surface and a plane. For example, the first outer peripheral surface 411 includes a connecting arc surface and a second anti-rotation surface 412 that are interconnected. Alternatively, the first outer peripheral surface 411 may also include two connecting arc surfaces and two second anti-rotation surfaces 412, with the two second anti-rotation surfaces 412 facing each other and the two connecting arc surfaces facing each other, and both connecting arc surfaces connecting between the two second anti-rotation surfaces 412. That is, the shape of the first column 41 along a cross-section parallel to the XY plane is approximately racetrack-shaped.

[0072] In some embodiments, the second anti-rotation surface 412 may also be a curved surface. For example, the first outer peripheral surface 411 includes an interconnected connecting arc surface and a second anti-rotation surface 412, the radius of curvature of the second anti-rotation surface 412 being different from the radius of curvature of the connecting arc surface. Alternatively, the outline of the first outer peripheral surface 411 may also be elliptical or irregular.

[0073] It should be noted that in this embodiment, the shape of the first column 41 is not specifically limited, as long as the outer contour of the first outer peripheral surface 411 of the first column 41 is not circular.

[0074] The protrusion 42 and flange 43 are respectively connected to opposite sides of the first column 41 along its height direction. In this embodiment, both the protrusion 42 and flange 43 are cylindrical. The area of ​​the flange 43 along its cross-section parallel to the XY plane is smaller than the area of ​​the first column 41 along its cross-section parallel to the XY plane. Furthermore, the orthographic projection of the flange 43 along the Z direction lies entirely within the orthographic projection of the first column 41 along the Z direction. For example, when the shape of the cross-section of the first column 41 parallel to the XY plane is a regular hexagon, the outline of the orthographic projection of the flange 43 along the Z direction is the inscribed circle of the outline of the orthographic projection of the first column 41 along the Z direction.

[0075] Flange 43 is used for electrical connection with connecting piece. In this embodiment, by setting the orthographic projection of flange 43 along the Z direction to be completely located within the orthographic projection of first column 41 along the Z direction, the installation of first pole post 40a can be facilitated, that is, the first pole post 40a can be easily inserted into the through hole 201 of first upper plastic 20a.

[0076] The area of ​​the cross-section of protrusion 42 parallel to the XY plane is greater than the area of ​​the cross-section of the first column 41 parallel to the XY plane. Furthermore, the orthographic projection of protrusion 42 along the Z direction completely covers the orthographic projection of the first column 41 along the Z direction. Figure 9As shown, the outer peripheral surface of the protrusion 42 protrudes from the outer peripheral surface of the first column 41, and the protrusion 42 forms a limiting portion 421 on the outer peripheral edge of the first column 41. The limiting portion 421 is used to cooperate with the first upper plastic 20a to improve the connection stability between the first pole post 40a and the first upper plastic 20a, and to improve the insulation effect of the first upper plastic 20a on the first pole post 40a.

[0077] Please see Figure 10 and Figure 11 , Figure 10 yes Figure 6 The diagram shows the structure of the first upper plastic 20a in the battery cell 100. Figure 11 yes Figure 10 The diagram shows the structure of the first upper plastic 20a from another angle.

[0078] The first upper plastic 20a is annular. The first upper plastic 20a has a through hole 201. The through hole 201 penetrates the first upper plastic 20a along its height direction, that is, it penetrates the first upper plastic 20a along the Z direction. The through hole 201 is used for the first pole post 40a to pass through.

[0079] The first upper plastic body 20a includes a body 21 and a protrusion 22. The body 21 includes a first surface 211, a second surface 212, a second outer peripheral surface 213, and a second inner peripheral surface 214. The first surface 211 and the second surface 212 are disposed opposite to each other along the thickness direction of the body 21, and the second outer peripheral surface 213 connects the first surface 211 and the second surface 212. The body 21 is provided with a first mounting through hole 215. The opening 52 of the first mounting through hole 215 is located on the first surface 211, and the first mounting through hole 215 at least partially penetrates the second surface 212. The second inner peripheral surface 214 is disposed opposite to the second outer peripheral surface 213. It can be understood that the second inner peripheral surface 214 is the sidewall surface of the first mounting through hole 215.

[0080] The second outer peripheral surface 213 includes a positioning surface 2131 and a connecting surface 2132. The positioning surface 2131 and the connecting surface 2132 are connected. The positioning surface 2131 is a plane. In this embodiment, the connecting surface 2132 is an arc surface, which can save material while ensuring the thickness of the first upper plastic 20a, and can also improve the smoothness of the second outer peripheral surface 213. In other embodiments, the connecting surface 2132 can also be a plane.

[0081] Specifically, in this embodiment, there are two positioning surfaces 2131 and two connecting surfaces 2132. The two positioning surfaces 2131 are arranged opposite to each other and parallel to each other, and the two connecting surfaces 2132 are arranged opposite to each other and are both connected between the two positioning surfaces 2131. The positioning surfaces 2131 are used to position the electrical connector 210 to improve the installation accuracy of the electrical connector 210.

[0082] The protrusion 22 is annular. The protrusion 22 has a second mounting through hole 221. The second mounting through hole 221 penetrates the protrusion 22 along its height direction, that is, along the Z-direction. The protrusion 22 includes a third inner peripheral surface 222 and a third outer peripheral surface 223. The third inner peripheral surface 222 and the third outer peripheral surface 223 are arranged opposite to each other. It can be understood that the third inner peripheral surface 222 is the inner wall surface of the second mounting through hole 221. The structure of the second mounting through hole 221 is adapted to the structure of the first column 41, and the outline of the third inner peripheral surface 222 is consistent with or approximately the same as the outline of the first outer peripheral surface 411.

[0083] The second mounting through hole 221 is non-cylindrical, meaning its cross-section along the XY plane is non-circular. The third inner circumferential surface 222 includes a first anti-rotation surface 224. In this embodiment, the first anti-rotation surface 224 is planar. That is, the third inner circumferential surface 222 is at least partially planar. Exemplarily, there are multiple first anti-rotation surfaces 224. These multiple first anti-rotation surfaces 224 are sequentially arranged around the inner circumference of the second mounting through hole 221 and connected end-to-end. It is understood that the cross-section of the second mounting through hole 221 along the XY plane is polygonal, meaning the outline of the third inner circumferential surface 222 is polygonal. Exemplarily, there are six first anti-rotation surfaces 224, which are sequentially arranged around the inner circumference of the second mounting through hole 221 and connected end-to-end. That is, the cross-section of the second mounting through hole 221 parallel to the XY plane is hexagonal. Specifically, the second mounting through hole 221 has a regular hexagonal shape along its cross-section parallel to the XY plane, and the third inner circumferential surface 222 is formed by connecting six planes end to end.

[0084] In some other embodiments, the shape of the second mounting through hole 221 along the cross section parallel to the XY plane can also be quadrilateral, pentagon, heptagon, octagon, etc. Alternatively, the third inner circumferential surface 222 can also be composed of an arc-shaped connecting arc surface and a planar first anti-rotation surface 224.

[0085] Alternatively, the first anti-rotation surface 224 can also be a curved surface. For example, the third inner circumferential surface 222 includes a connecting arc surface and the first anti-rotation surface 224 that are interconnected, and the radius of curvature of the connecting arc surface is different from the radius of curvature of the first anti-rotation surface 224. Alternatively, the outline of the third inner circumferential surface 222 can also be elliptical or irregular.

[0086] In this embodiment, the shape of the third outer peripheral surface 223 is the same as that of the third inner peripheral surface 222, and the third outer peripheral surface 223 is arranged parallel to the third inner peripheral surface 222 to simplify the manufacturing process of the protrusion 22, that is, to simplify the manufacturing process of the first upper plastic 20a. The outline of the third outer peripheral surface 223 is non-circular, that is, the cross-section of the third outer peripheral surface 223 along the XY plane is non-circular. The third outer peripheral surface 223 includes a fourth anti-rotation surface 225. In this embodiment, the fourth anti-rotation surface 225 is planar. That is, at least part of the third outer peripheral surface 223 is planar. Exemplarily, there are multiple fourth anti-rotation surfaces 225. Multiple fourth anti-rotation surfaces 225 are arranged sequentially around the outer periphery of the protrusion 22, and are connected end-to-end. It can be understood that the outline of the third outer peripheral surface 223 is polygonal, that is, the cross-section of the third outer peripheral surface 223 along the XY plane is polygonal. For example, there are six fourth anti-rotation surfaces 225, which are arranged sequentially around the outer periphery of the protrusion 22 and connected end to end. That is, the outline of the third outer peripheral surface 223 is hexagonal. Specifically, the outline of the third outer peripheral surface 223 is a regular hexagon. At the same time, the outline of the third outer peripheral surface 223 is consistent with or approximately the same as the outline of the first pole post through hole 13a.

[0087] In some embodiments, the outline of the third outer peripheral surface 223 may also be quadrilateral, pentagonal, heptagonal, octagonal, etc.; or, the third outer peripheral surface 223 may also be composed of an arc-shaped connecting arc surface and a planar fourth anti-rotation surface 225.

[0088] In some embodiments, the fourth anti-rotation surface 225 may also be a curved surface. For example, the third outer peripheral surface 223 includes a connecting arc surface and the fourth anti-rotation surface 225 connected by an arc, and the radius of curvature of the connecting arc surface and the radius of curvature of the fourth anti-rotation surface 225 are different; or, the outline of the third outer peripheral surface 223 may also be elliptical or irregular.

[0089] The protrusion 22 is connected to the second surface 212 of the body 21. The second mounting through hole 221 communicates with the first mounting through hole 215 and together form the through hole 201 of the first upper plastic 20a. The cross-sectional area of ​​the second mounting through hole 221 is smaller than that of the first mounting through hole 215. That is, the projection of the first mounting through hole 215 along the Z direction completely covers the projection of the second mounting through hole 221 along the Z direction. The outer periphery of the projection of the first mounting through hole 215 along the Z direction extends beyond the outer periphery of the projection of the second mounting through hole 221 along the Z direction, thereby forming a limiting stage 216 on the bottom wall of the first mounting through hole 215. The limiting stage 216 is used to limit the first pole post 40a.

[0090] Please combine Figure 7The first upper plastic 20a is installed on the end cap 10, the protrusion 22 passes through the first pole post through hole 13a, and the body 21 is located on the top surface 11 of the end cap 10. In this embodiment, the third outer peripheral surface 223 contacts the inner wall of the first pole post through hole 13a, and the body 21 contacts the top surface 11 of the end cap 10. The first pole post 40a passes through the through hole 201 of the first upper plastic 20a. The flange 43 passes through the first upper plastic 20a and extends out of the through hole 201, and is used for electrical connection with the first connector 70a. The first column 41 is located in the second mounting through hole 221, and the first outer peripheral surface 411 and the third inner peripheral surface 222 are opposite to and in contact with each other. The second anti-rotation surface 412 is parallel to and in contact with the first anti-rotation surface 224. Specifically, when there are multiple first anti-rotation surfaces 224 and multiple second anti-rotation surfaces 412, each second anti-rotation surface 412 is correspondingly arranged with a first anti-rotation surface 224, and each second anti-rotation surface 412 is parallel to and in contact with the corresponding first anti-rotation surface 224. Furthermore, the second anti-rotation surfaces 412 and the first anti-rotation surfaces 224 are mutually stopped along the circumferential direction of the first pole post 40a. The protrusion 42 is located within the first mounting through hole 215 of the body 21 and contacts the inner wall of the first mounting through hole 215. Specifically, the outer peripheral surface of the protrusion 42 is arranged opposite to and in contact with the inner peripheral surface of the body 21, and the limiting portion 421 of the protrusion 42 abuts against the limiting platform 216 within the first mounting through hole 215.

[0091] It is understandable that when the first pole post 40a is subjected to an external torsional force, the first post 41 has a tendency to rotate relative to the protrusion 22. The first outer peripheral surface 411 abuts against the third inner peripheral surface 222. Specifically, the second anti-rotation surface 412 abuts against the first anti-rotation surface 224. Since the outer contours between the first outer peripheral surface 411 and the third inner peripheral surface 222 are both non-cylindrical, and the first anti-rotation surface 224 and the second anti-rotation surface 412 are both planar, the first anti-rotation surface 224 can restrict the rotation of the second anti-rotation surface 412, thereby restricting the rotation of the first post 41 around its axis, and thus restricting the rotation of the first pole post 40a.

[0092] In this embodiment, by providing a second anti-rotation surface 412 on the first pole post 40a and a first anti-rotation surface 224 that cooperates with the second anti-rotation surface 412 on the first upper plastic 20a, the second anti-rotation surface 412 can prevent the first pole post 40a from rotating relative to the first upper plastic 20a. This can improve the connection stability between the first pole post 40a and the first upper plastic 20a, and increase the torque between the first pole post 40a and the first upper plastic 20a. It can also reduce or even avoid the first pole post 40a from twisting relative to the first upper plastic 20a when subjected to external force, thereby preventing the welding failure of the first pole post 40a and the first connector 70a from causing the sealing failure of the first pole post 40a. For example, when the electrical connector 210 is poorly welded to the first pole post 40a and needs to be disassembled, the end cap assembly 1 provided in this embodiment can prevent the electrical connector 210 from causing the first pole post 40a to rotate relative to the first upper plastic 20a by providing a second anti-rotation surface 412 on the first pole post 40a and a first anti-rotation surface 224 on the first upper plastic 20a.

[0093] It should be noted that since both the first column 41 and the second mounting through hole 221 are non-cylindrical, when the first upper plastic 20a is assembled with the first terminal post 40a, it will be difficult for the first column 41 to be accurately aligned within the mounting through hole 201, which will affect the assembly efficiency. In this embodiment, by providing a positioning surface 2131 on the second outer peripheral surface 213 of the first upper plastic 20a, the first upper plastic 20a can be positioned, so that when the first upper plastic 20a is installed on the first terminal post 40a, the first upper plastic 20a can be quickly aligned with the first terminal post 40a, and the gripping area can be increased, thereby improving the efficiency of installing the first upper plastic 20a on the first terminal post 40a and improving the assembly efficiency of the end cap assembly 1 and the battery cell 100.

[0094] For example, in this embodiment, the cross-sections of the first column 41 and the second mounting through hole 221 are both regular hexagons, the outline of the third inner circumferential surface 222 is a regular hexagon, and the two positioning surfaces 2131 of the second outer circumferential surface 213 are respectively parallel to the two first anti-rotation surfaces 224 arranged opposite to each other in the third inner circumferential surface 222. During the process of installing the first upper plastic 20a onto the first pole post 40a, the two positioning surfaces 2131 can be paralleled and aligned with the two second anti-rotation surfaces 412 arranged opposite to each other in the first column 41. Then, the first upper plastic 20a is fitted onto the outer circumference of the first pole post 40a, and the first column 41 passes through the second mounting through hole 221. At this time, the second anti-rotation surfaces 412 and the first anti-rotation surfaces 224 correspond one-to-one and are arranged parallel, thus completing the assembly between the first upper plastic 20a and the first pole post 40a.

[0095] Please combine Figure 2In this embodiment, by setting a positioning surface 2131 on the second outer peripheral surface 213 of the first upper plastic 20a, the electrical connector 210 can also be positioned to ensure the connection angle and connection position of the electrical connector 210, thereby improving the connection yield between the electrical connector 210 and the terminal 40. Specifically, when the positioning surface 2131 is parallel to the width direction of the battery cell 100 and the shape of the electrical connector 210 is rectangular, during the process of welding the electrical connector 210 to the first terminal 40a, the edge of the electrical connector 210 along the Y direction can be parallel to and aligned with the positioning surface 2131, or the included angle between the edge of the electrical connector 210 along the Y direction and the positioning surface 2131 can be adjusted to achieve a preset angle, and then the electrical connector 210 is welded to the first terminal 40a to realize the assembly of the electrical connector 210 and the first terminal 40a.

[0096] Furthermore, in this embodiment, by setting the second outer peripheral surface 213 of the first upper plastic 20a to combine a flat surface and an arc surface, the first upper plastic 20a can have a positioning function while also saving material on the first upper plastic 20a while maintaining the thickness of the body 21 of the first upper plastic 20a. That is, in this embodiment, by simultaneously providing a positioning surface 2131 and an arc-shaped connecting surface 2132 on the second outer peripheral surface 213 of the first upper plastic 20a, the assembly efficiency of the energy storage device 200 can be improved while reducing the production cost of the battery cell 100 and the energy storage device 200.

[0097] Meanwhile, in this embodiment, by providing two positioning surfaces 2131 opposite to each other on the second outer peripheral surface 213 of the first upper plastic 20a, the first upper plastic 20a can be easily clamped, making it convenient to move or place the first upper plastic 20a.

[0098] Furthermore, in this embodiment, by setting the cross-sectional area of ​​the protrusion 42 to be larger than the cross-sectional area of ​​the first column 41, and forming a limiting platform 216 on the first upper plastic 20a, the contact area between the first pole post 40a and the first upper plastic 20a can be increased. At the same time, the limiting platform 216 can limit the protrusion 42 in the Z direction, thereby improving the connection stability between the first pole post 40a and the first upper plastic 20a.

[0099] Please combine Figure 7 and Figure 12 , Figure 12 yes Figure 6 A partial structural diagram of the end cap 10 in the battery cell 100 shown.

[0100] The first pole through-hole 13a is non-cylindrical, and its outline is consistent with or substantially the same as the outline of the third outer peripheral surface 223. The inner wall surface of the first pole through-hole 13a includes a third anti-rotation surface 131. In this embodiment, the third anti-rotation surface 131 is planar. That is, at least part of the inner wall surface of the first pole through-hole 13a is planar. There are multiple third anti-rotation surfaces 131. These multiple third anti-rotation surfaces 131 are sequentially arranged around the inner wall surface of the first pole through-hole 13a, and are connected end-to-end. It can be understood that the cross-section of the first pole through-hole 13a along the XY plane is polygonal. That is, the outline of the inner wall surface of the first pole through-hole 13a is polygonal. For example, there are six third anti-rotation surfaces 131, which are sequentially arranged around the inner wall surface of the first pole through-hole 13a, and are connected end-to-end. That is, the cross-sectional shape of the first pole post through hole 13a along the XY plane is hexagonal. Specifically, the cross-sectional shape of the first pole post through hole 13a along the XY plane is a regular hexagon. That is, the outline of the inner wall surface of the first pole post through hole 13a is a regular hexagonal structure.

[0101] In some embodiments, the shape of the first pole through hole 13a along the cross section parallel to the XY plane can also be quadrilateral, pentagon, heptagon, octagon, etc. Alternatively, the inner wall surface of the first pole through hole 13a can also be composed of an arc-shaped connecting arc surface and a planar third anti-rotation surface 131.

[0102] In some embodiments, the third anti-rotation surface 131 may also be a curved surface. For example, the inner wall surface of the first pole through hole 13a includes a connecting arc surface and the third anti-rotation surface 131 that are connected to each other, and the radius of curvature of the connecting arc surface and the radius of curvature of the third anti-rotation surface 131 are different. Alternatively, the outline of the inner wall surface of the first pole through hole 13a may also be elliptical or irregular.

[0103] When the first upper plastic 20a and the first pole post 40a are installed on the end cap 10, the protrusion 22 of the first upper plastic 20a passes through the first pole post through hole 13a. The third outer peripheral surface 223 is opposite to and parallel to the inner wall of the first pole post through hole 13a, and the third outer peripheral surface 223 is in contact with the inner wall of the first pole post through hole 13a. The fourth anti-rotation surface 225 is parallel to and in contact with the third anti-rotation surface 131. Furthermore, the fourth anti-rotation surface 225 and the third anti-rotation surface 131 are mutually stopped along the circumference of the first upper plastic 20a. Specifically, when there are multiple third anti-rotation surfaces 131 and multiple fourth anti-rotation surfaces 225, the multiple fourth anti-rotation surfaces 225 are arranged one-to-one with the multiple third anti-rotation surfaces 131, and each fourth anti-rotation surface 225 is parallel to and in contact with the corresponding third anti-rotation surface 131.

[0104] In this embodiment, by providing a fourth anti-rotation surface 225 on the third outer peripheral surface 223 of the first upper plastic 20a, and providing a third anti-rotation surface 131 that cooperates with the fourth anti-rotation surface 225 on the inner wall surface of the first pole post through hole 13a, the third anti-rotation surface 131 can prevent the first upper plastic 20a from rotating relative to the end cap 10, thereby improving the connection stability between the first upper plastic 20a and the end cap 10, and increasing the torque between the first upper plastic 20a and the end cap 10, reducing or even avoiding the torsion of the first upper plastic 20a relative to the end cap 10 when subjected to external force, and further improving the prevention of sealing failure of the first pole post 40a. Specifically, the end cap assembly 1 provided in this embodiment can reduce or even avoid the torsion of the first upper plastic 20a relative to the end cap 10 when the first upper plastic 20a is subjected to external force by increasing the torque between the first upper plastic 20a and the end cap 10. This can prevent the first upper plastic 20a from causing the first pole post 40a to twist, thereby preventing the first pole post 40a from failing to seal due to welding failure between the first pole post 40a and the first connector 70a.

[0105] For example, in this embodiment, when the electrical connector 210 is poorly welded to the first pole post 40a and needs to be disassembled, the end cap assembly 1 provided in this embodiment can prevent the electrical connector 210 from rotating relative to the end cap 10 by providing a fourth anti-rotation surface 225 on the first upper plastic 20a and a third anti-rotation surface 131 on the inner wall surface of the first pole post through hole 13a.

[0106] It should be noted that, since the outline of the third outer peripheral surface 223 of the first upper plastic 20a is not circular and the first pole post through hole 13a is not cylindrical, when the first upper plastic 20a is installed in the first pole post through hole 13a, it will be difficult for the first upper plastic 20a to be accurately aligned in the first pole post through hole 13a, which will affect the assembly efficiency.

[0107] In this embodiment, by providing a positioning surface 2131 on the second outer peripheral surface 213 of the first upper plastic 20a, the first upper plastic 20a can be positioned when it is installed in the first electrode through hole 13a, so that the first upper plastic 20a can be quickly aligned with the first electrode through hole 13a, ensuring that the positioning surface 2131 and the end cap 10 can be placed at a set angle, thereby enabling the first upper plastic 20a to be smoothly installed in the first electrode through hole 13a of the end cap 10, and further improving the assembly efficiency of the end cap assembly 1 and the battery cell 100.

[0108] Please combine Figure 6 , Figure 7 and Figure 13 , Figure 13 yes Figure 6 A schematic diagram of the structure of the lower plastic 30 in the battery cell 100 shown.

[0109] The lower plastic 30 is provided with an electrode post hole 31, a second explosion-proof hole 32, a second liquid injection hole 33, and a guide hole 34. The second explosion-proof hole 32 penetrates the lower plastic 30 along its thickness direction. The second explosion-proof hole 32 is positioned opposite to the first explosion-proof hole 14 located on the end cap 10 and opposite to the explosion-proof valve 80. When the internal pressure of the battery cell 100 is too high, the pressurized gas located in the receiving cavity 51 will enter between the lower plastic 30 and the explosion-proof valve 80 through the second explosion-proof hole 32, and then impact the explosion-proof valve 80, causing the explosion-proof valve 80 to open and release pressure, thereby preventing the battery cell 100 from exploding and improving the safety performance of the battery cell 100 and the energy storage device 200.

[0110] The second injection hole 33 penetrates the lower plastic 30 along its thickness direction and is spaced apart from the second explosion-proof hole 32. The second injection hole 33 is opposite to and communicates with the first injection hole 15 provided on the end cap 10, and the second injection hole 33 communicates with the receiving cavity 51 of the housing 50. In the electrolyte injection process of the battery cell 100, the electrolyte flows into the receiving cavity 51 of the housing 50 through the first injection hole 15 and the second injection hole 33 to wet the electrode assembly 60.

[0111] The flow guide hole 34 penetrates the lower plastic 30 along its thickness direction, and is spaced apart from the second explosion-proof hole 32 and the second injection hole 33. In this embodiment, there are multiple flow guide holes 34. These multiple flow guide holes 34 are spaced apart on the lower plastic 30. In this embodiment, by providing flow guide holes 34 in the lower plastic 30, the electrolyte flowing between the lower plastic 30 and the end cap 10 during the electrolyte injection process of the battery cell 100 can flow into the receiving cavity 51 through the flow guide holes 34, thereby increasing the injection speed and preventing some electrolyte from remaining on the upper surface of the lower plastic 30, thus avoiding waste of electrolyte.

[0112] In this embodiment, two electrode holes 31 are used. The two electrode holes 31 are a first electrode hole 31a and a second electrode hole 31b. Both the first electrode hole 31a and the second electrode hole 31b penetrate the lower plastic 30 along the thickness direction of the lower plastic 30. The first electrode hole 31a and the second electrode hole 31b are spaced apart along the length direction of the lower plastic 30, that is, spaced apart along the X direction, and the second explosion-proof hole 32, the second injection hole 33, and the guide hole 34 are all located between the first electrode hole 31a and the second electrode hole 31b. The first electrode hole 31a is used for the first upper plastic 20a and the first electrode 40a to pass through, and the second electrode hole 31b is used for the first upper plastic 20a and the first electrode 40a to pass through.

[0113] The first pole hole 31a is non-cylindrical, and its outline is consistent with or substantially the same as the outline of the third outer peripheral surface 223 of the first upper plastic 20a. The inner wall surface of the first pole hole 31a includes a fifth anti-rotation surface 311. The fifth anti-rotation surface 311 is planar. That is, at least part of the inner wall surface of the first pole hole 31a is planar. In this embodiment, there are multiple fifth anti-rotation surfaces 311. Multiple fifth anti-rotation surfaces 311 are sequentially arranged around the inner wall surface of the first pole hole 31a, and are connected end-to-end. It can be understood that the cross-section of the first pole hole 31a along the XY plane is polygonal. That is, the outline of the inner wall surface of the first pole hole 31a is polygonal. For example, there are six fifth anti-rotation surfaces 311, which are sequentially arranged around the inner wall surface of the first pole hole 31a, and are connected end-to-end. That is, the cross-sectional shape of the first pole post hole 31a along the XY plane is hexagonal. Specifically, the cross-sectional shape of the first pole post hole 31a along the XY plane is a regular hexagon. In other words, the outline of the inner wall surface of the first pole post hole 31a is a regular hexagonal structure.

[0114] In some embodiments, the shape of the first pole post hole 31a along the cross section parallel to the XY plane can also be quadrilateral, pentagon, heptagon, octagon, etc. Alternatively, the inner wall surface of the first pole post hole 31a can also be composed of an arc-shaped connecting arc surface and a planar fifth anti-rotation surface 311.

[0115] In some embodiments, the fifth anti-rotation surface 311 may also be a curved surface. For example, the inner wall surface of the first pole hole 31a includes a connecting arc surface and the fifth anti-rotation surface 311 that are connected to each other, and the radius of curvature of the connecting arc surface and the radius of curvature of the fifth anti-rotation surface 311 are different. Alternatively, the outline of the inner wall surface of the first pole hole 31a may also be elliptical or irregular.

[0116] The lower plastic 30 is disposed at the bottom of the end cap 10 and is stacked with the end cap 10 along the Z direction, and the lower plastic 30 is fixedly connected to the end cap 10. For example, the surface of the lower plastic 30 facing the end cap 10 has a heat-fused post, which is heat-fused to the bottom of the end cap 10. The first pole hole 31a and the first pole through hole 13a of the end cap 10 are arranged opposite each other along the Z direction, and the protrusion 22 of the first upper plastic 20a passes through both the first pole through hole 13a and the first pole hole 31a. The third outer peripheral surface 223 is opposite to and parallel to the inner wall of the first pole hole 31a, and contacts the inner wall of the first pole hole 31a. The fourth anti-rotation surface 225 and the fifth anti-rotation surface 311 are parallel and opposite each other. Furthermore, the fifth anti-rotation surface 311 and the fourth anti-rotation surface 225 are mutually stopped along the circumference of the first upper plastic 20a. Specifically, when there are multiple fourth anti-rotation surfaces 225 and multiple fifth anti-rotation surfaces 311, the multiple fourth anti-rotation surfaces 225 are set in a one-to-one correspondence with the multiple fifth anti-rotation surfaces 311, and each fourth anti-rotation surface 225 is set parallel to and opposite to the corresponding fifth anti-rotation surface 311.

[0117] In this embodiment, the end cap assembly 1 further includes a sealing ring 90. The sealing ring 90 has an annular structure, and its shape is adapted to the shape of the first pole post hole 31a. Specifically, the sealing ring 90 has a regular hexagonal structure. The sealing ring 90 is sleeved on the outer periphery of the protrusion 22 and located between the third outer peripheral surface 223 and the inner wall of the first pole post hole 31a, so as to achieve a seal between the third outer peripheral surface 223 and the inner wall of the first pole post hole 31a, thereby achieving a seal for the first pole post 40a.

[0118] In this embodiment, by providing a fourth anti-rotation surface 225 on the first upper plastic 20a and a fifth anti-rotation surface 311 that cooperates with the fourth anti-rotation surface 225 on the inner wall surface of the first pole hole 31a of the lower plastic 30, the fifth anti-rotation surface 311 can prevent the upper plastic 20 from rotating relative to the lower plastic 30, thereby improving the connection stability between the first upper plastic 20a and the lower plastic 30. That is, it can further improve the installation stability of the upper plastic 20 and increase the torque between the first upper plastic 20a and the lower plastic 30, reduce or even avoid the first upper plastic 20a from twisting relative to the lower plastic 30 when subjected to external force, and further prevent the sealing failure of the first pole 40a. Specifically, the end cap assembly 1 provided in this embodiment increases the torque between the first upper plastic 20a and the lower plastic 30, thereby further reducing or even preventing the first upper plastic 20a from twisting relative to the end cap 10 when subjected to external force. This can further prevent the first upper plastic 20a from causing the first pole post 40a to twist, and thus further prevent the welding failure of the first pole post 40a and the first connector 70a from causing the sealing failure of the first pole post 40a.

[0119] For example, in this embodiment, when the electrical connector 210 is poorly welded to the first pole post 40a and needs to be disassembled, the end cap assembly 1 provided in this embodiment can prevent the electrical connector 210 from rotating relative to the lower plastic 30 by providing a fourth anti-rotation surface 225 on the first upper plastic 20a and a fifth anti-rotation surface 311 on the lower plastic 30.

[0120] It is understood that the end cap assembly 1 provided in this embodiment, the first upper plastic 20a, the end cap 10 and the lower plastic 30 can all limit the first pole post 40a. When the first pole post 40a is subjected to torsional force, the first upper plastic 20a, the end cap 10 and the lower plastic 30 can simultaneously prevent the first pole post 40a from rotating around its axial direction.

[0121] Please see Figure 14 , Figure 14 yes Figure 6 A schematic diagram of the structure of the first connector 70a in the battery cell 100 shown.

[0122] The first connector 70a includes a first connecting portion 71 and a second connecting portion 72. The first connecting portion 71 and the second connecting portion 72 are connected at an angle. In this embodiment, the first connecting portion 71 and the second connecting portion 72 are connected perpendicularly. In some other embodiments, the angle between the first connecting portion 71 and the second connecting portion 72 may be slightly greater than 90 degrees or slightly less than 90 degrees. The first connecting portion 71 is provided with a first connecting hole 711. The first connecting hole 711 penetrates the first connecting portion 71 along its thickness direction. In this embodiment, the first connecting hole 711 is a circular hole, and the shape of the first connecting hole 711 is adapted to the shape of the flange 43.

[0123] The surface of the first connecting portion 71 is also provided with a limiting groove 712. The limiting groove 712 is arranged around the outer periphery of the first connecting hole 711. The outer contour of the limiting groove 712 is consistent with or substantially the same as the outer contour of the protrusion 22 of the first upper plastic 20a. The sidewall of the limiting groove 712 includes a sixth anti-rotation surface 713. The sixth anti-rotation surface 713 is planar. That is, at least part of the sidewall of the limiting groove 712 is planar. In this embodiment, there are multiple sixth anti-rotation surfaces 713. Multiple sixth anti-rotation surfaces 713 are arranged sequentially around the sidewall of the limiting groove 712, and are connected end to end. It can be understood that the shape of the outline of the sidewall of the limiting groove 712 is polygonal. Specifically, the shape of the outline of the sidewall of the limiting groove 712 is a regular hexagon.

[0124] Please combine Figure 7 and Figure 15 , Figure 15 yes Figure 5 The diagram shows a partial structural view of the battery cell 100 from another angle.

[0125] The first connector 70a is installed on the side of the lower plastic 30 facing away from the end cap 10. The first connecting part 71 faces the lower plastic 30 and is fixedly and electrically connected to the first pole post 40a. Specifically, the first connecting part 71 and the first pole post 40a are fixedly connected by welding. The limiting groove 712 faces the lower plastic 30, and the protrusion 22 of the upper plastic 20 is at least partially located within the limiting groove 712. Specifically, the end of the protrusion 22 facing away from the body 21 is located within the limiting groove 712. The third outer peripheral surface 223 is opposite to and parallel to the side wall of the limiting groove 712. The sixth anti-rotation surface 713 and the fourth anti-rotation surface 225 are parallel and in contact with each other. Specifically, when there are multiple sixth anti-rotation surfaces 713 and multiple fourth anti-rotation surfaces 225, the multiple sixth anti-rotation surfaces 713 are arranged one-to-one with the multiple fourth anti-rotation surfaces 225, and each sixth anti-rotation surface 713 is parallel and in contact with its corresponding fourth anti-rotation surface 225.

[0126] In this embodiment, by providing a sixth anti-rotation surface 713 on the side wall of the limiting groove 712, the sixth anti-rotation surface 713 can further prevent the first upper plastic 20a from rotating, thereby further improving the installation stability of the first upper plastic 20a, and further preventing the first pole post 40a from driving the first upper plastic 20a to rotate.

[0127] In this design, the flange 43 of the first pole post 40a passes through the first connecting hole 711, and the outer peripheral surface of the flange 43 is electrically connected to the inner wall of the first connecting hole 711. Specifically, the outer peripheral surface of the flange 43 can directly contact the inner wall of the first connecting hole 711, or it can be fixedly connected and electrically connected by welding. This improves the stability of the electrical connection between the first connector 70a and the first pole post 40a.

[0128] The second connecting portion 72 extends into the receiving cavity 51 of the housing 50 and is fixedly and electrically connected to the positive electrode tab of the electrode assembly 60. The current of the electrode assembly 60 flows through the positive electrode tab to the second connecting portion 72, and then to the first connecting portion 71, and from the first connecting portion 71 through the first terminal post 40a to the outside of the battery cell 100.

[0129] It should be noted that in the prior art, when the electrical connector 210 is removed from the first electrode post 40a, the electrical connector 210 will cause the first electrode post 40a to twist, which will cause relative rotation between the first electrode post 40a and the first connector 70a. This will affect the welding effect between the first electrode post 40a and the first connector 70a, as well as the connection stability between the first electrode post 40a and the first connector 70a. Consequently, it will affect the electrical connection stability between the first electrode post 40a and the electrode assembly 60, and cause the seal of the first electrode post 40a to fail.

[0130] The battery cell 100 provided in this embodiment improves the torque between the first electrode post 40a and the first upper plastic 20a by providing a second anti-rotation surface 412 on the first electrode post 40a and a first anti-rotation surface 224 on the first upper plastic 20a. This reduces or even prevents the first electrode post 40a from twisting relative to the first upper plastic 20a when subjected to external force. It can prevent the rotation of the first electrode post 40a from affecting the connection stability between the first electrode post 40a and the first connector 70a, and also prevent the rotation of the first electrode post 40a from affecting the welding effect and connection stability between the first connector 70a and the electrode assembly 60. In this way, it can improve the electrical connection stability between the first electrode post 40a, the first connector 70a, and the electrode assembly 60, and prevent the sealing failure of the first electrode post 40a.

[0131] Please see Figure 5 and Figure 6 The structure and connection relationship of the second pole post 40b, the second upper plastic 20b, the second pole post through hole 13b, the second pole post hole 31b, and the second connector 70b can all be referred to the above description, and will not be repeated here.

[0132] Specifically, the second upper plastic 20b includes a body 21 and a protrusion 22. The body 21 has a first mounting through hole 215, and the protrusion 22 has a second mounting through hole 221. The protrusion 22 is connected to the body 21 along the thickness direction of the end cap assembly 1, and the second mounting through hole 221 communicates with the first mounting through hole 215. The inner wall surface of the second mounting through hole 221 includes a first anti-rotation surface 224, which is a plane. The outer peripheral surface of the body 21 includes a positioning surface 2131, which is a plane. The second pole post 40b includes a first post 41 and a protrusion 42, which are connected along the thickness direction of the end cap assembly 1. The outer peripheral surface of the first post 41 includes a second anti-rotation surface 412, which is a plane.

[0133] The second upper plastic part 20b is disposed on the end cap 10, and the protrusion 22 passes through the second pole post through hole 13b and is connected to the end cap 10. The body 21 is disposed on the top surface 11 of the end cap 10. The second pole post 40b is installed on the second upper plastic part 20b, and the first post 41 passes through the second mounting through hole 221. The second anti-rotation surface 412 is parallel to and in contact with the first anti-rotation surface 224. The protrusion 42 passes through the first mounting through hole 215 and is connected to the body 21.

[0134] In this embodiment, by providing a second anti-rotation surface 412 on the second pole post 40b and a first anti-rotation surface 224 that cooperates with the second anti-rotation surface 412 on the second upper plastic 20b, the second anti-rotation surface 412 of the second upper plastic 20b can prevent the second pole post 40b from rotating relative to the second upper plastic 20b. This improves the connection stability between the second pole post 40b and the second upper plastic 20b, increases the torque between the second pole post 40b and the second upper plastic 20b, reduces or even avoids the second pole post 40b from twisting relative to the second upper plastic 20b when subjected to external force, and thus avoids the second pole post 40b from failing to seal due to welding failure between the second pole post 40b and the second connector 70b.

[0135] Furthermore, in this embodiment, by providing a positioning surface 2131 on the second upper plastic 20b, the electrical connector 210 can also be positioned to ensure the connection angle and connection position between the electrical connector 210 and the second pole post 40b, thereby improving the connection yield between the electrical connector 210 and the second pole post 40b.

[0136] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An end cap assembly, characterized in that, include: An end cap, wherein the end cap is provided with a pole post through hole, the pole post through hole penetrating the top surface and the bottom surface of the end cap; The upper plastic part includes a body and a protrusion. The body has a first mounting through hole, and the protrusion has a second mounting through hole. The protrusion is connected to the body along the thickness direction of the end cap assembly. The second mounting through hole communicates with the first mounting through hole. The inner wall surface of the second mounting through hole includes a first anti-rotation surface. The outer peripheral surface of the body includes a positioning surface, which is a plane. The upper plastic part is disposed on the end cap, the protrusion passes through the pole through hole, and the body is disposed on the top surface of the end cap. The electrode post includes a first column and a protrusion, the first column and the protrusion being connected along the thickness direction of the end cap assembly, the outer peripheral surface of the first column including a second anti-rotation surface; the electrode post is mounted on the upper plastic, the protrusion passing through the first mounting through hole, the first column passing through the second mounting through hole, the second anti-rotation surface contacting the first anti-rotation surface, and the second anti-rotation surface and the first anti-rotation surface mutually stopping each other along the circumference of the electrode post.

2. The end cap assembly according to claim 1, characterized in that, The number of positioning surfaces is two, and the two positioning surfaces are parallel and opposite to each other; The outer peripheral surface of the body also includes two connecting surfaces, both of which are arc surfaces. The two connecting surfaces are arranged opposite to each other and are connected between the two positioning surfaces.

3. The end cap assembly according to claim 1, characterized in that, Both the first anti-rotation surface and the second anti-rotation surface are planar, and the first anti-rotation surface and the second anti-rotation surface are arranged parallel to each other.

4. The end cap assembly according to claim 3, characterized in that, The number of first anti-rotation surfaces is multiple, and multiple first anti-rotation surfaces are arranged sequentially around the inner wall of the second mounting through hole, and connected end to end; the number of second anti-rotation surfaces is multiple, and multiple second anti-rotation surfaces are arranged sequentially around the outer periphery of the first column, and connected end to end. Multiple second anti-rotation surfaces are provided in one-to-one correspondence with multiple first anti-rotation surfaces, and each second anti-rotation surface is arranged parallel to and in contact with the corresponding first anti-rotation surface.

5. The end cap assembly according to claim 4, characterized in that, The inner wall of the second mounting through hole has a regular hexagonal outline, the outer peripheral surface of the first column has a regular hexagonal outline, and the outline of the outer peripheral surface of the first column is consistent with the outline of the inner wall of the second mounting through hole.

6. The end cap assembly according to claim 1, characterized in that, The inner wall surface of the through hole of the pole post includes a third anti-rotation surface, which is a plane; the outer peripheral surface of the protrusion includes a fourth anti-rotation surface, which is a plane, and the fourth anti-rotation surface is parallel to the third anti-rotation surface and in contact with it.

7. The end cap assembly according to claim 6, characterized in that, There are multiple third anti-rotation surfaces, which are arranged sequentially around the inner wall of the pole post through hole and connected end to end; there are multiple fourth anti-rotation surfaces, which are arranged sequentially around the outer periphery of the protrusion and connected end to end. The plurality of fourth anti-rotation surfaces are provided in a one-to-one correspondence with the plurality of third anti-rotation surfaces, and each fourth anti-rotation surface is arranged parallel to and in contact with the corresponding third anti-rotation surface.

8. The end cap assembly according to claim 6 or 7, characterized in that, The end cap assembly further includes a lower plastic, which includes an electrode post hole that penetrates the lower plastic along its thickness direction; the inner wall surface of the electrode post hole includes a fifth anti-rotation surface, which is a plane. The lower plastic is disposed at the bottom of the end cap and is fixedly connected to the end cap. The pole hole and the pole through hole are arranged opposite to each other. The protrusion passes through the pole through hole and the pole hole. The fourth anti-rotation surface and the fifth anti-rotation surface are parallel and opposite to each other.

9. The end cap assembly according to claim 8, characterized in that, The end cap assembly also includes a sealing ring, which is fitted around the outer periphery of the protrusion and located inside the pole hole, and the sealing ring seals between the protrusion and the lower plastic.

10. A single battery cell, characterized in that, The device includes a housing, an electrode assembly, a connector, and an end cap assembly as described in any one of claims 1 to 9; the housing has an opening and a receiving cavity, the receiving cavity communicating with the opening; the electrode assembly is disposed within the receiving cavity, the end cap assembly covers the opening and is fixedly connected to the housing; the connector is electrically connected between the electrode post and the electrode assembly.

11. The battery cell according to claim 10, characterized in that, The connector includes a first connecting part and a second connecting part, which are connected at an angle to each other; the first connecting part is provided with a first connecting hole, which penetrates the first connecting part along the thickness direction of the first connecting part. The electrode post also includes a flange, which is connected to the side of the first post facing away from the protrusion; the first connecting part is located at the bottom of the end cap, the flange passes through the first connecting hole, and the flange contacts the inner wall of the first connecting hole; the second connecting part is electrically connected to the electrode assembly.

12. The battery cell according to claim 11, characterized in that, The first connecting part is welded to the flange.

13. The battery cell according to claim 11 or 12, characterized in that, The first connecting portion has a limiting groove on its surface facing the end cap. The limiting groove surrounds the outer periphery of the first connecting hole. The side wall of the limiting groove includes a sixth anti-rotation surface, which is a plane. The protrusion is at least partially located in the limiting groove, and the fourth anti-rotation surface on the outer periphery of the protrusion is parallel to and in contact with the sixth anti-rotation surface.

14. An energy storage device, characterized in that, It includes an electrical connector and at least two battery cells as described in any one of claims 10 to 13, wherein the at least two battery cells are arranged side by side, and the electrical connector is electrically connected between the terminals of two adjacent battery cells.

15. The energy storage device according to claim 14, characterized in that, At least one edge of the electrical connector is flush with the positioning surface.

16. An electrical appliance, characterized in that, Includes the energy storage device as described in claim 14 or 15, the energy storage device being used to supply power to the electrical equipment.

Images