Top cover assembly, energy storage apparatus, and energy storage system

Abstract

A top cover assembly (100), an energy storage apparatus, and an electrical device. The top cover assembly (100) comprises a welding ring (6), a connecting member (8), and a lower insulating member (5). The welding ring (6) is provided with an opposite first surface (61) and second surface (62) in the thickness direction of the welding ring, the connecting member (8) is provided with an opposite third surface (811) and fourth surface (812) in the thickness direction of the connecting member, and the fourth surface (812) protrudes relative to the second surface (62) in the direction away from the third surface (811).

Description

Top cover assembly, energy storage device and energy storage system

[0001] Priority information

[0002] This application claims priority and benefits of patent application No. 202311515865.7 filed with the State Intellectual Property Office of China on November 14, 2023, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the field of energy storage technology, and in particular to a top cover assembly, an energy storage device, and an energy storage system. Background Art

[0004] When the temperature inside the energy storage device is too high or the pressure is too high, a chemical reaction occurs inside it, generating gas, which causes the pressure inside the energy storage device to continue to increase, easily causing damage to the energy storage device, and in severe cases, causing the energy storage device to explode.

[0005] Summary of the Invention

[0006] Based on this, it is necessary to provide a top cover assembly to address the problem that chemical reactions occur inside the current energy storage device, generating gas, causing the pressure inside the energy storage device to continuously increase, which can easily cause damage to the energy storage device and even cause the energy storage device to explode.

[0007] In a first aspect, a top cover assembly comprises:

[0008] The welding ring has a first surface and a second surface opposite to each other along its thickness direction;

[0009] a connecting member connected to at least a portion of the outer circumference of the welding ring, wherein the connecting member has a third surface and a fourth surface opposite to each other along its own thickness direction, the third surface and the first surface are arranged on the same side, and the fourth surface is connected to the second surface;

[0010] a lower insulating member connected to the outer peripheral surface of the welding ring and connected to the first surface and the third surface;

[0011] The fourth surface is protruded relative to the second surface in a direction away from the third surface.

[0012] In a second aspect, an embodiment of the present application provides an energy storage device, which includes a top cover assembly as described in the first aspect.

[0013] In a third aspect, an embodiment of the present application provides an energy storage system, which includes the energy storage device as described in the second aspect, and the energy storage device is used to supply power to the energy storage system.

[0014] Compared with the prior art, the present application has the following beneficial effects: the fourth side of the connector is arranged to protrude relative to the second side, facing away from the third side, so that after the energy storage device is assembled with the top cover assembly, the fourth side of the connector faces the side of the battery cell, and the second side of the solder ring faces the side of the battery cell. In the height direction of the battery, the fourth side is lower than the third side, thereby creating a height difference between the connector and the solder ring, thereby creating a space for gas discharge between the solder ring and the battery cell inside the energy storage device. After gas is generated within the energy storage device, it can be temporarily stored in this space, thereby balancing the internal air pressure of the energy storage device and preventing excessive pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a perspective view of a top cover assembly according to an embodiment.

[0016] FIG. 2 is a perspective view of a top cover assembly according to an embodiment from another perspective.

[0017] FIG. 3 is a top view of a top cover assembly according to an embodiment.

[0018] FIG4 is a partial cross-sectional view along the AA direction in FIG3 .

[0019] FIG5 is an enlarged view of point B in FIG4.

[0020] FIG6 is another partial cross-sectional view along the AA direction in FIG3 .

[0021] FIG. 7 is a perspective view of a partial structure of an upper insulating member in an embodiment of the present application.

[0022] Explanation of the accompanying drawings: 100, top cover assembly; 1, cover plate; 11, first surface; 12, second surface; 21, first upper insulating member; 211, first pole mounting hole; 212, first step portion; 213, first limiting portion; 22, second upper insulating member; 221, second pole mounting hole; 222, second step portion; 223, second limiting portion; 31, positive pole; 311, first body; 312, second body; 313, fourth body; 32, negative pole; 321, third body; 322, fifth body; 4, groove; 5, lower insulating member; 6, welding ring; 61, first surface; 62, second surface; 7, sealing member; 8, connecting member; 81, extension portion; 82, transition portion; 83, welding portion; 811, third surface; 812, fourth surface. DETAILED DESCRIPTION

[0023] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0024] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0025] The embodiment of the present application provides an energy storage system, which may include a large-scale electric energy storage system, which plays a role in adjusting the load curve, shaving peaks and filling valleys, improving the utilization efficiency of distribution network equipment and lines, and participating in grid frequency regulation. The large-scale mobile energy storage system adopts an integrated container design scheme, which can be conveniently used for grid support and regional temporary power supply support. The energy storage system also includes medium-sized electric energy storage systems, such as mobile charging equipment, that is, electrical equipment that temporarily needs to be charged in buildings, large conferences, charging stations (charging piles), etc. The energy storage system also includes small mobile energy storage systems, which mainly refer to small energy storage systems installed in residential houses or corporate parks. Its operating modes include independent operation, supporting operation with renewable energy power generation equipment such as small wind turbines and rooftop photovoltaics, and household heat storage equipment.

[0026] The energy storage system includes an energy storage device, which is used to supply power to electrical equipment to meet the operating requirements of the energy storage system. The number of energy storage devices can be one or more. When the number of energy storage devices is multiple, the multiple energy storage devices can be connected in series, in parallel, or in a mixed manner of series and parallel to achieve a larger capacity and power. The energy storage device may include but is not limited to single cells, battery modules, battery packs, battery systems, etc. For example, the energy storage device may be a secondary battery such as a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid (or lead-acid) battery, a lithium-ion battery, a polymer lithium-ion battery, or a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery. When the energy storage device is a single cell, it may be a square battery.

[0027] The energy storage device generally includes a battery cell, a shell for accommodating the battery cell, and a top cover assembly. A positive electrode ear and a negative electrode ear are provided on the top of the battery cell, and the top cover assembly includes a positive electrode post and a negative electrode post. The electrode post is a component in the battery that connects the inside and outside of the battery. One end of the electrode post is in contact with the electrode ear inside the shell, and the other end is connected to other equipment outside the energy storage device to enable the energy storage device to realize the charging and discharging function. The positive electrode post is matched with the positive electrode ear with a higher potential and usually uses an aluminum electrode post. The negative electrode post is matched with the negative electrode ear with a lower potential and usually uses a copper-aluminum composite electrode post, in which the copper part of the copper-aluminum composite electrode is connected to the negative electrode ear. During the assembly of the top cover assembly, the positive and negative electrode posts need to be assembled to the correct position of the cover plate so that the positive electrode post is connected to the positive electrode ear and the copper part of the negative electrode post is connected to the negative electrode ear to ensure that the circuit is correctly connected and current conduction is achieved. At present, the positive and negative poles are similar in shape and size, and are easily reversed during assembly. When the copper part of the negative pole contacts the positive ear, the potential mismatch will cause oxidation corrosion of the energy storage device, reducing the service life of the energy storage device.

[0028] Please refer to Figures 1 and 2 together. Based on the above-mentioned problem, the embodiment of the present application provides a top cover assembly 100, which includes a cover plate 1, a pole, and an upper insulating member. Specifically, the cover plate 1 is a plate-shaped structure as a whole, and has a first surface 11 and a second surface 12 arranged opposite to each other. The cover plate 1 has two mounting holes that pass through the first surface 11 and the second surface 12. When the top cover assembly 100 is assembled on an energy storage device, the first surface 11 is a side surface facing away from the battery cell of the energy storage device, and the second surface 12 is a side surface close to the battery cell of the energy storage device.

[0029] Referring to Figures 1 and 2 , the positive electrode column 31 and the negative electrode column 32 are spaced apart along the length of the cover plate 1 . Referring to Figure 3 , the positive electrode column 31 includes a coaxially arranged first body 311 and a second body 312 . The first body 311 is located on the side of the second body 312 facing away from the first surface 11 . In other words, the first body 311 is located on the top surface of the second body 312 along its own height direction. The radial dimension of the second body 312 is greater than the radial dimension of the first body 311 , so that the second body 312 protrudes radially outward relative to the first body 311 . Referring to Figure 3 , the negative electrode column 32 includes a third body 321 . The radial dimension of the third body 321 is greater than the radial dimension of the first body 311 and smaller than the radial dimension of the second body 312 . In the embodiment of the present application, the first body 311 , the second body 312 , and the third body 321 are all cylindrical. The positive electrode post 31 and the negative electrode post 32 are both inserted into the cover plate 1 from top to bottom (i.e., from the side of the cover plate 1 away from the battery cell to the side close to the battery cell). During the assembly process of the top cover assembly 100, the top surfaces of the first body 311 and the third body 321 are directly identified and compared. In order to facilitate intuitive distinction between the positive and negative electrode posts, the radial diameter d2 of the second body 312 is made larger than the radial diameter d3 of the third body 321, and the radial diameter d3 of the third body 321 is larger than the radial diameter d1 of the first body 311. The top surfaces of the first body 311 and the third body 321 have the same shape, both being complete dome surfaces, with only the radial dimensions of the dome surfaces being different. The radial dimensions of at least part of the first pole mounting hole 211 are larger than the radial dimensions of the second pole mounting hole 221 to accommodate positive pole posts 31 and negative pole posts 32 of different diameters. The radial dimension of the first pole mounting hole 211 refers to the radial dimension of the inner circumference of the first limiting portion 213, and the radial dimension of the second pole mounting hole 221 is the radial dimension of the inner circumference of the second limiting portion 223. The radial dimension of the inner circumference of the first limiting portion 213 is greater than the radial dimension of the inner circumference of the second limiting portion 223, so that the first limiting portion 213 can only be assembled with the second main body 312, and thus can only correspond to the positive pole 31, and the second limiting portion 223 can only be assembled with the third main body 321, and thus can only correspond to the positive pole 31.

[0030] Referring to Figures 4 and 6 , the upper insulators include a first upper insulator 21 and a second upper insulator 22. These upper insulators ensure an insulated connection between the positive and negative electrode posts 31 and 32 and the cover plate 1, preventing creepage. The first upper insulator 21 is inserted into one mounting hole, and the second upper insulator 22 is inserted into the other mounting hole. Both the first and second upper insulators 21 and 22 abut against the walls of the mounting holes and also against the first surface 11 of the cover plate 1.

[0031] Please refer to Figure 4. The first upper insulating member 21 is provided with a first pole mounting hole 211. The positive pole 31 is inserted into the first pole mounting hole 211 so that the outer peripheral surface of the second body 312 abuts against the hole wall of the first pole mounting hole 211. The bottom surface of the second body 312 and the first surface 11 of the cover plate 1 are indirectly connected via the first upper insulating member 21, thereby playing a limiting role, preventing the positive pole 31 from being displaced relative to the cover plate 1 along its own height direction, causing the positive pole 31 to sink, and preventing the energy storage device from short-circuiting due to the sinking of the positive pole 31.

[0032] Referring to Figure 6 , the second upper insulating member 22 defines a second electrode mounting hole 221. The negative electrode 32 is inserted into the first electrode mounting hole 211 so that the outer circumference of the third body 321 abuts against the wall of the second electrode mounting hole 221. The bottom surface of the third body 321 and the first surface 11 of the cover plate 1 are indirectly connected via the second upper insulating member 22.

[0033] The embodiment of the present application can avoid the reverse installation of the positive and negative poles 32 by simultaneously adjusting the radial dimensions of the positive and negative poles 32, the first pole mounting hole 211, and the second pole mounting hole 221. Specifically, by limiting the size relationship between the radial dimensions of the first pole mounting hole 211 and the radial dimensions of the second pole mounting hole 221, the radial dimensions of the first pole mounting hole 211 correspond to the radial dimensions of the second body 312 to complete the assembly abutment, and the radial dimensions of the second pole mounting hole 221 correspond to the radial dimensions of the third body 321 to complete the assembly abutment. In order to better identify the positive pole 31 and the negative pole 32, a first body 311 with a smaller radial dimension is provided on the top surface of the second body 312, so that the first body 311 can serve as an identification structure to identify the positive pole 31, so that it can be assembled to the first pole mounting hole 211 with a larger radial dimension through the first body 311 and the second body 312. In other words, the first body 311 with a smaller radial dimension directly corresponds to the first pole mounting hole 211 with a larger radial dimension, and the third body 321 with a larger radial dimension directly corresponds to the second pole mounting hole 221 with a smaller radial dimension. When the positive pole 31 and the negative pole 32 are reversed, due to the mismatch in radial dimensions, neither the first body 311 nor the second body 312 of the positive pole 31 can match the second pole mounting hole 221, and the third body 321 of the negative pole 32 cannot match the first pole mounting hole 211. As a result, the positive pole 31 can only match the first pole mounting hole 211, and the negative pole 32 can only match the second pole mounting hole 221, which prevents reverse polarity use of the energy storage device and protects the energy storage device.

[0034] Referring to Figure 4 , the positive electrode column 31 also includes a fourth body 313, which is coaxially connected to the second body 312 and is located on the side of the second body 312 facing away from the first body 311. In other words, the second body 312 is located between the first body 311 and the fourth body 313, wherein the first body 311 is located on the top surface of the second body 312, and the fourth body 313 is located on the bottom surface of the second body 312. The outer peripheral surface of the fourth body 313 abuts the hole wall of the first pole mounting hole 211. The fourth body 313 is indirectly connected to the hole wall of the mounting hole of the cover plate 1 through the first upper insulating member 21 to achieve insulation between the fourth body 313 and the cover plate 1. The first body 311, the second body 312, and the fourth body 313 are all made of aluminum, and the fourth body 313 is connected to the positive electrode ear in the energy storage device.

[0035] Referring to Figure 4 , the radial dimension of the fourth body 313 is smaller than that of the second body 312, so that the second body 312 protrudes radially outward relative to the first body 311 and the fourth body 313. This gives the positive electrode post 31 a spindle shape, with a larger center and smaller ends. This facilitates identification of the positive electrode post 31 and facilitates insertion from top to bottom into the first electrode post mounting hole 211. It will be understood that the outer circumferential surfaces of the second body 312 and the fourth body 313 simultaneously abut against the wall of the first electrode post mounting hole 211, and the first upper insulator 21 is configured as a stepped shape to match the shape of the positive electrode post 31.

[0036] Referring to Figure 6 , in some embodiments, the negative electrode post 32 further includes a fifth body 322 , which is coaxially abutted against the third body 321 . The bottom surface of the third body 321 is connected to the first surface 11 of the cover plate 1 via the fifth body 322 and the second upper insulating member 22 . In the negative electrode post 32 of the present embodiment, the third body 321 is made of aluminum, and the fifth body 322 is made of a copper-aluminum composite material. The third main body 321 is in the shape of a cylinder, and the fifth main body 322 includes a copper part and a trapezoidal aluminum part. The copper part is provided with a placement groove, and the aluminum part can abut against the placement groove. The opposite ends of the copper part along its own width direction extend away from the aluminum part to form a boss. The top surface of the boss is connected to the bottom surface of the aluminum part. The outer peripheral surface of the boss abuts against the hole wall of the second pole mounting hole 221 and is flush with the outer peripheral surface of the third main body 321. The bottom surface of the boss of the third main body 321 is connected to the first surface 11 of the cover plate 1 through the second upper insulating member 22.

[0037] Referring to Figure 6 , the radial dimension of the fifth body 322 gradually decreases along its height, giving the negative electrode post 32 a T-shape with a larger top and a smaller bottom, facilitating downward insertion into the first electrode mounting hole 211. The outer circumferences of the third body 321 and the fifth body 322 simultaneously abut against the wall of the second electrode mounting hole 221, and the second upper insulator 22 is also stepped to match the shape of the negative electrode post 32.

[0038] At present, the structure of the positive and negative poles is affected by the processing technology, and it restricts the performance of the energy storage device. The diameters of the two ends of the current positive and negative poles are larger, while the middle diameter is smaller, that is, the two ends of the poles are convex relative to the middle, and the cross-section of the poles along the axial direction is in the shape of an "I". This structure usually needs to be formed by combining stamping and CNC turning processes. The production process is relatively complicated, and it is difficult to control the processing dimensional accuracy of the poles. There are certain errors in the processing process. In addition, the tops of the positive and negative poles are both provided with steps that extend continuously around their own central axes, which also requires additional processing steps, affecting the processing accuracy. In addition, the different shapes and sizes of the positive and negative poles may lead to different current densities (that is, the current intensity per unit area), and the overcurrent protection capabilities of the positive and negative poles will fail, which will affect the charging and discharging rates and reduce the life and stability of the energy storage device. In the embodiment of the present application, the positive electrode column 31 and the negative electrode column 32 have a simple structure and can be directly formed by stamping, which reduces the processing steps and improves the processing accuracy, thereby better controlling the radial dimensions of the first body 311, the second body 312 and the third body 321. On this basis, by adjusting the radial dimension relationship of the first body 311, the second body 312 and the third body 321, overcurrent protection can be met and the life of the energy storage device can be extended.

[0039] In some embodiments, the difference between the radial dimension of the second body 312 and the radial dimension of the third body 321 is T1, and the difference between the radial dimension of the third body 321 and the radial dimension of the first body 311 is T2, satisfying T2≥T1, so that the conductivity and stability of the first body 311 and the second body 312 are similar to those of the third body 321, thereby balancing the current intensity between the positive electrode column 31 and the negative electrode column 32, and improving the overcurrent protection capability of the positive and negative electrode columns 32.

[0040] Referring to Figure 4 , in some embodiments, the first upper insulating member 21 includes a first step 212 and a first stopper 213 that abut against each other. The first step 212 abuts the wall of the mounting hole and the first surface 11, while the first stopper 213 extends toward a side facing away from the first surface 11. The outer circumference of the second body 312 abuts the inner circumference of the first stopper 213. The bottom surface of the second body 312 abuts the top surface of the first step 212. It is understood that the first step 212 includes a first portion and a second portion connected at right angles. The outer circumference of the fourth body 313 is indirectly connected to the wall of the mounting hole via the first portion. The bottom surface of the second body 312 is connected to the top surface of the second portion and is indirectly connected to the first surface 11 of the cover plate 1 via the second portion. The curved connection between the first step 212 and the first stopper 213 increases the insulating contact area between the positive electrode 31 and the cover plate 1, improving the effectiveness of preventing creepage.

[0041] Referring to Figure 6 , in some embodiments, the second upper insulating member 22 includes a second step portion 222 and a second stop portion 223 connected to each other. The second step portion 222 abuts the wall of the mounting hole and the first surface 11 of the cover plate 1. The second stop portion 223 extends toward a side facing away from the first surface 11. The outer circumference of the third body 321 abuts the inner circumference of the second stop portion 223. In other words, the second step portion 222 includes a third portion and a fourth portion connected at right angles. The outer circumference of the copper portion of the fifth body 322 abuts the inner circumference of the third portion, indirectly connecting to the wall of the mounting hole of the cover plate 1 through the third portion. The bottom surface of the boss of the copper portion abuts the top surface of the fourth portion, indirectly connecting to the first surface 11 of the cover plate 1 through the fourth portion. The outer circumference of the third body 321 and the outer circumference of the boss simultaneously abut the inner circumference of the second stop portion 223. The bent second step portion 222 and the second limiting portion 223 can increase the insulating contact area between the negative electrode column 32 and the cover plate 1, further improving the effect of preventing creepage.

[0042] Referring to FIG. 7 , in some embodiments, the inner circumferences of the first and second limiting portions 213 and 223 are provided with grooves 4. The grooves 4 may extend continuously around the positive electrode post 31 or the negative electrode post 32, or may be multiple grooves spaced apart to surround the positive electrode post 31 or the negative electrode post 32. The provision of grooves 4 prevents the upper insulator from sticking to the front mold during the injection molding process, facilitating mold removal.

[0043] In some embodiments, the groove 4 has a groove depth along the radial direction of the upper insulator, which is 0.02 mm to 0.2 mm. The groove 4 has a groove width along the axial direction of the upper insulator, which is 0.1 mm to 3 mm. For example, the groove depth can be any value within the above range, such as 0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm, 0.2 mm, etc. The groove width can be any value within the above range, such as 0.1 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, or 3.0 mm. If the groove depth and width of the groove 4 are below the above lower limits, the upper insulator may still partially adhere to the front mold. If they are above the above upper limits, the thickness of the upper insulator is insufficient, the insulation is reduced, and creepage occurs between the pole and the cover plate 1.

[0044] Please refer to Figures 4 and 6. During the charging and discharging process of the energy storage device, the temperature of the battery cell will gradually increase, and the internal pressure of the battery will also gradually increase. When the internal temperature of the energy storage device is too high or the pressure is too high, it is easy to cause damage or explosion. Based on this problem, the top cover assembly 100 of the embodiment of the present application also includes a welding ring 6, a connector 8 and a lower insulating member 5. Please refer to Figure 5. The welding ring 6 has a first surface 61 and a second surface 62 relative to each other along its own thickness direction. The connector 8 is connected to at least part of the outer peripheral surface of the welding ring 6. The connecting member 8 has a third surface 811 and a fourth surface 812 relative to each other along its own thickness direction. The third surface 811 is arranged on the same side as the first surface 61, and the fourth surface 812 is connected to the second surface 62. The lower insulating member 5 is connected to the outer peripheral surface of the welding ring 6 and is also connected to the first surface 61 and the third surface 811. Please refer to Figure 5. The fourth surface 812 is arranged to protrude relative to the second surface 62 in a direction away from the third surface 811. Therefore, when the top cover assembly 100 is assembled to the energy storage device, along the height direction of the energy storage device, the fourth surface 812 of the connector 8 is lower than the second surface 62 of the welding ring 6, so that there is a height difference between the connector 8 and the welding ring 6, so that there is a pressure relief space between the welding ring 6 and the battery cell to accommodate part of the gas, thereby balancing the air pressure inside the energy storage device and reducing damage or explosion of the energy storage device.

[0045] The lower insulator 5 is connected to the second surface 12 of the cover plate 1. The welding ring 6 is mounted on the outer circumference of the terminal, and the upper insulator abuts the first surface 61 of the welding ring 6. The welding ring 6 enables the terminal to withstand greater vibration, current, and pressure. Made of the same material as the terminal to which it is directly connected, the welding ring 6 reduces welding difficulty and the risk of weld defects. Specifically, the welding ring 6 on the positive terminal 31 side is mounted on the outer circumference of the fourth body 313, which is made of aluminum. The welding ring 6 on the negative terminal 32 side is mounted on the outer circumference of the copper portion of the fifth body 322, which is also made of copper. Typically, the bottom surface of the welding ring 6 is flush with the bottom surface of the terminal to improve welding stability. However, when the fourth surface 812 of the connector 8 is flush with the bottom surface of the lower insulator 5 and there is a height difference between the welding ring 6 and the connector 8, the height of the welding ring 6 and the terminal can be reduced to reduce costs.

[0046] Referring to FIG. 2 , in some embodiments, the connector 8 includes an extension portion 81 and a transition portion 82. Referring to FIG. 4 and FIG. 6 , one side of the transition portion 81 is connected to at least a portion of the outer circumference of the welding ring 6, and the other side thereof is connected to the extension portion 81. Along the direction from the welding ring 6 to the extension portion 81, the transition portion 82 gradually bends in the direction from the third surface 811 to the fourth surface 812. The gradually curved transition portion 82 can relieve stress and improve welding stability.

[0047] Referring to FIG. 2 , in some embodiments, the connector 8 further includes a welding portion 83 , an extension portion 81 connected between the welding portion 83 and the transition portion 82 , and the length direction of the lower insulating member 5 is set at an angle to the extension portion 81 . The extension portion 81 can be symmetrically connected to both sides of the welding ring 6 along the center of the welding ring 6 to form a wing-shaped structure. During the assembly process of the top cover assembly 100 , the positive electrode column 31 is connected to the positive electrode welding ring, and the negative electrode column 32 is connected to the negative electrode welding ring on the side where the second surface 12 is located, and then the connector 8 is connected to the welding ring 6 . The welding portion 83 is set at an angle to the extension portion 81 , so that there is an inclined seam between the extension portion 81 and the lower insulating member 5 , which can play a guiding role, can reduce the deformation between the welding ring 6 and the pole, and between the connector 8 and the welding ring 6, and is conducive to controlling the penetration depth and reducing the connection defect rate. It should be noted that the top cover assembly 100 can be assembled by a welding process, such as ultrasonic welding, resistance welding, arc welding, laser welding, friction welding, etc., or by an assembly process such as stamping and riveting.

[0048] Please refer to Figures 4 and 6. The top cover assembly 100 also includes a seal 7. The outer peripheral surface of the upper insulating member, the first surface 61 of the welding ring 6, the side surface of the lower insulating member 5 and the second surface 12 of the cover plate 1 together constitute an accommodating cavity, and the seal 7 is embedded in the accommodating cavity. The seal 7 can be made of a flexible material or an elastic material, and has a certain elastic deformation ability. The seal 7 is tightly compressed between the welding ring 6 and the second surface 12 of the cover plate 1, filling the gap between the pole and the cover plate 1 to prevent leakage of the electrolyte inside the energy storage device. Optionally, the material of the upper insulating member and the lower insulating member 5 in the embodiment of the present application can be a material that can achieve insulation, such as plastic or rubber.

[0049] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A top cover assembly, wherein: The top cover assembly comprises: A welding ring having a first surface and a second surface opposite to each other along a thickness direction thereof; A connecting member connected to at least a portion of the outer peripheral surface of the welding ring, wherein the connecting member has a third surface and a fourth surface opposite to each other along its own thickness direction, the third surface and the first surface are arranged on the same side, and the fourth surface is connected to the second surface; A lower insulating member connected to the outer peripheral surface of the welding ring and connected to the first surface and the third surface at the same time; The fourth surface is disposed protruding relative to the second surface in a direction away from the third surface.

2. The top cover assembly according to claim 1, wherein: The connecting member includes an extension portion and a transition portion, one side of the transition portion is connected to at least a portion of the outer peripheral surface of the welding ring, and the other opposite side is connected to the extension portion, and along the direction from the welding ring to the extension portion, the transition portion gradually bends in the direction from the third surface to the fourth surface.

3. The top cover assembly according to claim 2, wherein: The connecting member further includes a welding portion, the extending portion is connected between the welding portion and the transition portion, and the extending portion is arranged at an angle with the length direction of the lower insulating member.

4. The top cover assembly according to claim 1, wherein: The top cover assembly also includes: A cover plate, comprising a first surface and a second surface disposed opposite to each other, the cover plate being provided with a mounting hole penetrating the first surface and the second surface, and the lower insulating member being connected to the second surface; An upper insulating member, inserted into the mounting hole and abutting against the first surface, the upper insulating member is provided with a pole mounting hole, and the upper insulating member abuts against the first surface of the welding ring; The pole is inserted into the pole mounting hole, the outer peripheral surface of the pole abuts against the hole wall of the pole mounting hole, and the outer peripheral surface of the pole abuts against the inner peripheral surface of the welding ring.

5. The top cover assembly according to claim 4, wherein: The upper insulating member includes a first upper insulating member and a second upper insulating member, the pole mounting hole includes a first pole mounting hole and a second pole mounting hole, the first upper insulating member is provided with the first pole mounting hole, the second upper insulating member is provided with the second pole mounting hole, and the radial size of at least part of the first pole mounting hole is greater than the radial size of the second pole mounting hole; The pole includes a positive pole and a negative pole, the positive pole includes a first main body and a second main body arranged coaxially, the negative pole includes a third main body, the radial dimension of the third main body is larger than the radial dimension of the first main body and smaller than the radial dimension of the second main body, the positive pole is inserted into the first pole mounting hole so that the outer peripheral surface of the second main body abuts against the hole wall of the first pole mounting hole, the first main body is located on the side of the second main body away from the first surface, and the negative pole is inserted into the second pole mounting hole so that the outer peripheral surface of the third main body abuts against the hole wall of the second pole mounting hole.

6. The top cover assembly according to claim 5, wherein: The first upper insulating member includes a first step portion and a first limiting portion connected to each other, and the second upper insulating member includes a second step portion and a second limiting portion connected to each other, the first step portion and the second step portion abut against the hole wall of the mounting hole and the first surface, the bottom surfaces of the first step portion and the second step portion abut against the first surface of the welding ring, and the first limiting portion and the second limiting portion extend toward a side away from the first surface; The bottom surface of the second body abuts against the top surface of the first step portion, the outer circumference of the second body abuts against the inner circumference of the first limiting portion, and the outer circumference of the third body abuts against the inner circumference of the second limiting portion.

7. The top cover assembly according to claim 6, wherein: The inner circumferences of the first limiting portion and the second limiting portion are provided with grooves.

8. The top cover assembly according to claim 7, wherein: The groove has a groove depth along the radial direction of the upper insulating member, and the groove depth is 0.02 mm to 0.2 mm, and / or the groove has a groove width along the axial direction of the upper insulating member, and the groove width is 0.1 mm to 3 mm.

9. An energy storage device, wherein: A top cover assembly comprising any one of claims 1 to 8.

10. An energy storage system, wherein: The energy storage device comprises the energy storage device as claimed in claim 9, wherein the energy storage device is used to supply power to the energy storage system.

Images