End cover assembly, energy storage device and electrical equipment

Abstract

The present application provides an end cap assembly, an energy storage device, and an electrical device. During the welding process between the adapter plate and the pole column, the lower plastic will not be scratched and fall off, preventing a short circuit inside the energy storage device and ensuring the reliability of the energy storage device. The mounting hole of the end cap penetrates the end cap along the thickness direction of the end cap. The lower plastic is mounted on one side in the thickness direction of the end cap. The first surface and the second surface of the lower plastic are arranged opposite to each other. The assembly hole of the lower plastic penetrates the first surface and the second surface along the thickness direction of the lower plastic and is communicated with the mounting hole. The boss of the lower plastic is arranged in the edge area of the second surface and is spaced from the assembly hole. The distance between the surface of the boss facing away from the second surface and the second surface is a first distance; the pole column penetrates the assembly hole and the mounting hole. The pole column includes a first end face, and the first end face is located on the side of the second surface facing away from the first surface, and the distance between the first end face and the second surface is a second distance, and the second distance is less than the first distance.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage, and in particular, to an end cap assembly, an energy storage device, and an electrical device. Background Art

[0002] A secondary battery (Rechargeable battery), also known as a rechargeable battery or a storage battery, refers to a battery that can be reused by activating active substances through charging after discharging. The recyclable characteristics of secondary batteries have gradually made them the main power source of electrical devices. As the demand for secondary batteries increases, people's requirements for various aspects of their performance are also getting higher and higher, especially for the reliability requirements of secondary battery use. In existing secondary batteries, the adapter plate is often assembled with the pole column by welding. However, during the process of butt welding the adapter plate with the pole column, the adapter plate is likely to scrape off the plastic, resulting in the shedding of metal debris. There is a probability that the metal debris will fall into the core of the battery inside, causing a short circuit inside the battery. Therefore, the safety performance of the battery is affected. Summary of the Invention

[0003] The present application provides an end cap assembly, an energy storage device, and an electrical device. During the welding process of the adapter plate with the pole column, the plastic will not be scraped off to cause the shedding of metal debris, preventing the metal debris from falling into the core inside the energy storage device and causing a short circuit inside the energy storage device, and ensuring the installation reliability of the energy storage device.

[0004] In a first aspect, the present application provides an end cap assembly for an energy storage device, including an end cap, a lower plastic, and a pole column. The end cap is provided with a mounting hole that penetrates the end cap along the thickness direction of the end cap. The lower plastic is installed on one side in the thickness direction of the end cap. The lower plastic includes a first surface and a second surface. Along the thickness direction of the end cap assembly, the first surface and the second surface are arranged in opposite directions. The lower plastic is provided with an assembly hole that penetrates the first surface and the second surface along the thickness direction of the lower plastic and is communicated with the mounting hole. The lower plastic is further provided with a boss, and the boss is arranged in the edge area of the second surface and is spaced from the assembly hole. The distance between the surface of the boss facing away from the second surface and the second surface is a first distance;

[0005] The pole column penetrates through the assembly hole and the mounting hole. The pole column includes a first end face facing the same direction as the second surface. The first end face is located on the side of the second surface away from the first surface and the distance between the first end face and the second surface is a second distance, and the second distance is less than the first distance.

[0006] Wherein, the end cap includes a third surface facing away from the lower plastic, the pole also includes a second end surface disposed opposite to the first end surface, the second end surface is located on a side of the third surface facing away from the second surface, and the distance between the second end surface and the first surface is a third distance, and the sum of the second distance and the third distance is less than the first distance.

[0007] Wherein, the end cap assembly further includes a protective film, the protective film is installed on the second surface and covers the first end surface.

[0008] Wherein, the thickness of the protective film is a fourth distance, and the first distance is greater than the sum of the second distance, the third distance and the fourth distance.

[0009] Wherein, the end cap assembly further includes an upper plastic, the upper plastic is connected between the pole and the end cap, and the surface of the upper plastic facing away from the end cap is located on a side of the second end surface facing the first surface.

[0010] Wherein, the pole is provided with a stepped groove, the opening of the stepped groove is located on the second end surface, the stepped groove penetrates the circumferential surface of the pole and is arranged around the pole, and the bottom wall surface of the stepped groove is located on a side of the surface of the upper plastic facing away from the end cap facing away from the second end surface, or the bottom wall surface of the stepped groove is flush with the surface of the upper plastic facing away from the end cap.

[0011] Wherein, the pole is provided with a blind hole, the opening of the blind hole is located on the second end surface, and the central axis of the blind hole coincides with the central axis of the pole.

[0012] Wherein, the pole further includes an annular structure, the annular structure is disposed on the second end surface, arranged around the blind hole, and spaced from the blind hole.

[0013] Wherein, there are a plurality of the annular structures, and along the direction from the central axis of the pole to the edge, the plurality of annular structures are arranged at intervals in sequence.

[0014] Wherein, the lower plastic is further provided with two protrusions, both of the two protrusions are disposed on the second surface and are located on a side of the boss facing the pole, along the width direction of the end cap assembly, the two protrusions are respectively located on opposite sides of the first end surface and are both spaced from the first end surface.

[0015] Wherein, both of the two protrusions abut against the surface of the boss facing the pole, and each protrusion includes a third end surface facing away from the second surface, and the third end surface is located between the surface of the boss facing away from the second surface and the second surface.

[0016] Wherein, each of the protrusions includes an inclined surface facing away from the boss, and the end cap assembly further includes a protective film that covers the first end surface and the inclined surfaces of the two protrusions, and forms a gap with the second surface.

[0017] In a second aspect, the present application provides an energy storage device, including a housing and any one of the above-mentioned end cap assemblies. The housing is provided with an opening, and the end cap assembly is installed on the housing and closes the opening.

[0018] In a third aspect, the present application provides an electrical equipment, including the above-mentioned energy storage device, and the energy storage device supplies power to the electrical equipment.

[0019] In the end cap assembly shown in the present application, the end surface of the pole protrudes from the second surface of the lower plastic, which can ensure that when the pole is welded to a connecting piece (not shown in the figure), the rhombic indentation formed on the end surface by ultrasonic welding of the connecting piece will not scrape the lower plastic and cause it to fall off, preventing internal short circuit of the energy storage device and ensuring the reliability of the energy storage device during use. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the embodiments of the present application will be described below.

[0021] Figure 1 is a schematic structural diagram of a household energy storage system according to an embodiment of the present application;

[0022] Figure 2 is Figure 1 a schematic structural diagram of the energy storage device in the household energy storage system shown;

[0023] Figure 3 is Figure 2 a schematic structural diagram of the end cap assembly in the first embodiment of the energy storage device shown;

[0024] Figure 4 is Figure 3 a schematic cross-sectional structural diagram of the end cap assembly shown after being cut along A-A;

[0025] Figure 5 is Figure 3 a schematic exploded structural diagram of the end cap assembly shown;

[0026] Figure 6 is Figure 5 a schematic structural diagram of the lower plastic in the end cap assembly shown;

[0027] Figure 7 is Figure 6 a schematic structural diagram of the lower plastic shown from another angle;

[0028] Figure 8Yes Figure 5 Schematic structural diagram of the end cover and the explosion-proof valve in the shown end cover assembly;

[0029] Figure 9 Yes Figure 5 Exploded structural diagram of the negative electrode assembly in the shown end cover assembly;

[0030] Figure 10 Yes Figure 9 Schematic structural diagram of the first pole column in the shown negative electrode assembly;

[0031] Figure 11 Yes Figure 10 Schematic cross-sectional structure diagram of the shown first pole column after being cut along B-B;

[0032] Figure 12 Yes Figure 3 Schematic structural diagram of the shown end cover assembly from another angle;

[0033] Figure 13 Yes Figure 4 Exploded structural diagram of the positive electrode assembly in the shown end cover assembly;

[0034] Figure 14 Yes Figure 2 Schematic structural diagram of the end cover assembly in the energy storage device under the second embodiment;

[0035] Figure 15 Yes Figure 14 Schematic partial structural diagram of the shown end cover assembly.

[0036] The names corresponding to the reference numerals in the figure are:

[0037] Power conversion device 2, first user load 3, second user load 4, energy storage device 1, housing 100, end cover assembly 200, lower plastic 10, end cover 20, explosion-proof valve 30, pole assembly 40, negative electrode assembly 50, positive electrode assembly 60, first surface 101, second surface 102, explosion-proof fence 11, assembly hole 103, avoidance groove 104, first assembly hole 103a, second assembly hole 103b, first avoidance groove 104a, second avoidance groove 104b, boss 12, first boss 12a, second boss 12b, third surface 201, fourth surface 202, explosion-proof hole 203, mounting hole 204, first mounting hole 204a, second mounting hole 204b, first pole 51, first sealing ring 52, first upper plastic 53, first end face 511, second end face 512, first column body part 513, first flange part 514, first blind hole 515, first stepped groove 516, first annular groove 517, first annular structure 518, first metal part 51a, second metal part 51b, first identification groove 531, protective film 70, second pole 61, second sealing ring 62, second upper plastic 63, second identification groove 631, protrusion 13, third end face 131, side face 132, gap 133. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application.

[0039] Since the energy required by people has strong temporality and spatiality, in order to rationally utilize energy and improve the energy utilization rate, it is necessary to store one form of energy in the same form or convert it into another form of energy through a medium or device, and then release it in a specific energy form based on future application needs. At present, the main way to generate green electric energy is to develop green energy such as photovoltaic and wind power to replace fossil energy.

[0040] At present, the generation of green electric energy generally depends on photovoltaic, wind power, water potential, etc. Wind energy and solar energy generally have problems of strong intermittency and large volatility, which will cause the power grid to be unstable. There is not enough electricity during peak electricity consumption, and there is too much electricity during low electricity consumption. The unstable voltage will also damage the power. Therefore, due to insufficient electricity demand or insufficient power grid acceptance capacity, the problem of "abandoning wind and light" may be caused. To solve these problems, energy storage is required. That is, the electric energy is converted into other forms of energy through physical or chemical means and stored, and the energy is converted into electric energy and released when needed. Simply put, energy storage is similar to a large "portable power bank". When photovoltaic and wind energy are sufficient, the electric energy is stored, and the stored energy is released when needed.

[0041] Taking electrochemical energy storage as an example, this solution provides an energy storage device. A set of chemical batteries are installed in the energy storage device, which mainly uses the chemical elements in the batteries as the energy storage medium. The charge and discharge process is accompanied by chemical reactions or changes of the energy storage medium. Simply put, the electrical energy generated by wind energy and solar energy is stored in the chemical batteries, and the stored electricity is released for use when the external electricity consumption reaches the peak, or transferred to areas with tight power supply for use again.

[0042] Currently, the application scenarios of energy storage (i.e., energy storage) are relatively extensive, including power generation side energy storage, grid side energy storage, and user side energy storage, etc. The types of corresponding energy storage devices include:

[0043] Large-scale energy storage power stations applied on the side of wind power and photovoltaic power stations can assist renewable energy power generation to meet grid connection requirements, and at the same time improve the utilization rate of renewable energy; as a high-quality active / reactive power regulation power source on the power source side, the energy storage power station realizes the load matching of electric energy in time and space, enhances the consumption capacity of renewable energy, reduces instantaneous power changes, reduces the impact on the power grid, improves the problem of new energy power generation consumption, and is of great significance in power grid system standby, alleviating the power supply pressure during peak loads, and peak shaving and frequency modulation.

[0044] Energy storage containers applied on the grid side are mainly used for peak shaving, frequency modulation, and alleviating grid congestion peak shaving. They can realize the peak shaving and valley filling of the electricity load, that is, charging the energy storage battery during the low valley of the electricity load and releasing the stored electricity during the peak period of the electricity load, so as to achieve the balance between power production and consumption.

[0045] Small energy storage cabinets applied on the user side are mainly used for self-generation and self-use of electricity, peak-valley price difference arbitrage, capacity charge management, and improving power supply reliability. According to different application scenarios, user side energy storage can be divided into industrial and commercial energy storage cabinets, household energy storage devices, energy storage charging piles, etc., which are generally used in combination with distributed photovoltaics. Industrial and commercial users can use energy storage for peak-valley price difference arbitrage and capacity charge management. In the electricity market implementing peak-valley electricity prices, by charging the energy storage system at low electricity prices and discharging the energy storage system at high electricity prices, peak-valley electricity price difference arbitrage is realized, and the electricity consumption cost is reduced. In addition, industrial enterprises applicable to two-part electricity prices can use the energy storage system to store energy during the low valley of electricity consumption and discharge electricity during the peak load, so as to reduce the peak power and the declared maximum demand, and achieve the purpose of reducing capacity electricity charges. Household photovoltaic with energy storage can improve the level of self-generation and self-use of electricity. Due to high electricity prices and poor power supply stability, the demand for household photovoltaic installations is thus driven. Considering that photovoltaics generate electricity during the day while users generally have higher loads at night, by configuring energy storage, photovoltaic power can be better utilized, the level of self-generation and self-use can be improved, and the electricity consumption cost can be reduced at the same time. In addition, energy storage needs to be configured in fields such as communication base stations and data centers for backup power supplies.

[0046] Please refer toFigure 1 , Figure 1 is a schematic structural diagram of a household energy storage system according to an embodiment of the present application, and the embodiment of the present application Figure 1 is described by taking the household energy storage scenario in user-side energy storage as an example. The energy storage device of the present application is not limited to the household energy storage scenario.

[0047] The present application provides a household energy storage system, which includes an electric energy conversion device 2 (photovoltaic panel), a first user load 3 (street lamp), a second user load 4 (such as household appliances like air conditioners), etc., and an energy storage device 1. The energy storage device 1 is a small energy storage box and can be installed on an outdoor wall in a wall-mounted manner. Specifically, the photovoltaic panel can convert solar energy into electric energy during the low electricity price period, and the energy storage device 1 is used to store the electric energy and supply it to the street lamp and household appliances for use during the high electricity price period, or supply power when the power grid is powered off / out of power.

[0048] Please refer to Figure 2 , Figure 2 is Figure 1 a schematic structural diagram of the energy storage device 1 in the household energy storage system shown.

[0049] In this embodiment, the energy storage device 1 is a block battery. The energy storage device 1 includes a housing 100, an electrode assembly (not shown in the figure), and an end cover assembly 200. The housing 100 has an opening (not shown in the figure), the housing 100 is provided with a receiving cavity (not shown in the figure), and an electrolyte is received in the receiving cavity. The electrode assembly is received in the receiving cavity and immersed in the electrolyte. The end cover assembly 200 is installed on one side of the housing 100 and closes the opening.

[0050] Please refer to Figures 3 to 5 , Figure 3 is Figure 2 a schematic structural diagram of the end cover assembly 200 of the energy storage device 1 in the first embodiment shown, Figure 4 is Figure 3 a schematic structural diagram of the end cover assembly 200 after being cut along the A-A line, Figure 5 is Figure 3 a schematic exploded view of the end cover assembly 200 shown. Among them, "being cut along the A-A line" means being cut along the plane where the A-A line is located, and similar descriptions in the following can be understood in the same way.

[0051] The end cover assembly 200 includes a lower plastic 10, an end cover 20, an explosion-proof valve 30, and two pole assemblies 40. The end cover 20 is installed on one side in the thickness direction of the lower plastic 10 (i.e., the thickness direction of the end cover assembly 200). The explosion-proof valve 30 and the two pole assemblies 40 are both installed on the end cover 20. Along the length direction of the end cover assembly 200, the two pole assemblies 40 are respectively located on opposite sides of the explosion-proof valve 30 and are both spaced apart from the explosion-proof valve 30. Among them, the two pole assemblies 40 are respectively a negative pole assembly 50 and a positive pole assembly 60.

[0052] Please refer to Figure 5 、 Figure 6 and Figure 7 , Figure 6 is Figure 5 a schematic structural view of the lower plastic 10 in the end cover assembly 200 shown in Figure 7 is Figure 6 a schematic structural view of the lower plastic 10 from another angle shown in

[0053] The lower plastic 10 includes a first surface 101 and a second surface 102, and the first surface 101 and the second surface 102 are arranged back to back along the thickness direction of the lower plastic 10. Among them, the first surface 101 is the surface of the lower plastic 10 facing the end cover 20, and the second surface 102 is the surface of the lower plastic 10 facing away from the end cover 20.

[0054] In this embodiment, the lower plastic 10 includes an explosion-proof fence 11, and the explosion-proof fence 11 penetrates through the first surface 101 and the second surface 102. Among them, the explosion-proof fence 11 is located in the middle of the lower plastic 10. The lower plastic 10 is provided with an assembly hole 103 and an avoidance groove 104. The assembly hole 103 penetrates through the lower plastic 10 along the thickness direction of the lower plastic 10. Among them, there are two assembly holes 103, and the two assembly holes 103 are respectively a first assembly hole 103a and a second assembly hole 103b. Along the length direction of the lower plastic 10 (i.e., the length direction of the end cover assembly 200), the first assembly hole 103a and the second assembly hole 103b are respectively located on opposite sides of the explosion-proof fence 11, and are both spaced apart from the explosion-proof fence 11.

[0055] The opening of the avoidance groove 104 is located on the second surface 102. The avoidance groove 104 is recessed from the second surface 102 towards the first surface 101, and penetrates through the hole wall surface of the assembly hole 103 to communicate with the assembly hole 103. Among them, there are two avoidance grooves 104, and the two avoidance grooves 104 are respectively a first avoidance groove 104a and a second avoidance groove 104b. The first avoidance groove 104a and the first assembly hole 103a are located on the same side of the explosion-proof fence 11, and surround the first assembly hole 103a and communicate with the first assembly hole 103a. The second avoidance groove 104b and the second assembly hole 103b are located on the same side of the explosion-proof fence 11, and surround the second assembly hole 103b and communicate with the second assembly hole 103b.

[0056] In addition, the lower plastic 10 is further provided with a boss 12. The boss 12 is provided on the second surface 102 and protrudes from the second surface 102 in a direction away from the first surface 101. Specifically, the boss 12 is provided in the edge area of the second surface 102, and is located on the side of the avoidance groove 104 away from the explosion-proof fence 11, and is spaced apart from the avoidance groove 104. Among them, the distance between the surface of the boss 12 facing away from the second surface 102 and the second surface 102 is a first distance H1 Exemplarily, H 1 = 4.65 mm.

[0057] In this embodiment, there are two bosses 12, which are the first boss 12a and the second boss 12b respectively. The first boss 12a is located on the side of the first avoidance groove 104a away from the explosion-proof fence 11 and is arranged at an interval from the first avoidance groove 104a. The second boss 12b is located on the side of the second avoidance groove 104b away from the explosion-proof fence 11 and is arranged at an interval from the second avoidance groove 104b.

[0058] Please refer to Figure 5 、 Figure 6 and Figure 8 , Figure 8 is Figure 5 the schematic structural diagram of the end cap 20 and the explosion-proof valve 30 in the end cap assembly 200 shown in the figure.

[0059] The end cap 20 includes a third surface 201 and a fourth surface 202, and the third surface 201 and the fourth surface 202 are arranged opposite to each other along the thickness direction of the end cap 20 (i.e., the thickness direction of the end cap assembly 200). Among them, the third surface 201 is the surface of the end cap 20 away from the lower plastic 10, and the fourth surface 202 is the surface of the end cap 20 facing the lower plastic 10.

[0060] The end cap 20 is provided with an explosion-proof hole 203 and a mounting hole 204, and both the explosion-proof hole 203 and the mounting hole 204 penetrate the end cap 20 along the thickness direction of the end cap 20 (i.e., the thickness direction of the end cap assembly 200). The explosion-proof hole 203 is located in the middle of the end cap 20 and is arranged opposite to the explosion-proof fence 11. There are two mounting holes 204, which are the first mounting hole 204a and the second mounting hole 204b respectively. Along the length direction of the end cap 20 (i.e., the length direction of the end cap assembly 200), the first mounting hole 204a is located on one side of the explosion-proof hole 203, is arranged at an interval from the explosion-proof hole 203, and is communicated with the first assembly hole 103a. The second mounting hole 204b is located on the other side of the explosion-proof hole 203, is arranged at an interval from the explosion-proof hole 203, and is communicated with the second assembly hole 103b.

[0061] The explosion-proof valve 30 is installed in the explosion-proof hole 203 and is fixedly connected to the hole wall of the explosion-proof hole 203. Exemplarily, the explosion-proof valve 30 is fixedly connected to the hole wall of the explosion-proof hole 203 by welding to be installed in the explosion-proof hole 203. It can be understood that since the explosion-proof hole 203 communicates the inside and the outside of the energy storage device 1, when the air pressure inside the energy storage device 1 is too high, the gas inside the energy storage device 1 can pass through the explosion-proof fence 11 and the explosion-proof hole 203 in sequence and be discharged to the outside of the energy storage device 1 in time. The explosion-proof valve 30 will rupture under the action of the air pressure, avoiding the explosion of the energy storage device 1 and improving the use reliability of the energy storage device 1.

[0062] See also Figure 6 , Figure 8 and Figure 9 , Figure 9 yes Figure 5 A schematic diagram of the exploded structure of the negative electrode assembly 50 in the end cap assembly 200 is shown.

[0063] The negative electrode assembly 50 includes a first pole 51, a first sealing ring 52 and a first upper plastic 53. The first pole 51 is inserted into the first assembly hole 103a of the lower plastic 10 and the first mounting hole 204a of the end cover 20. The first upper plastic 53 and the first sealing ring 52 are both sleeved on the first pole 51 and isolate the first pole 51 from the end cover 20 so that the first pole 51 is insulated from the end cover 20. The first upper plastic 53 is located on the side of the first sealing ring 52 away from the lower plastic 10.

[0064] It should be noted that during the assembly of the end cap assembly 200, the first assembly hole 103a of the lower plastic 10 is first aligned with the first mounting hole 204a of the end cap 20, and then the first pole 51 with the first sealing ring 52 is sequentially passed through the first assembly hole 103a of the lower plastic 10 and the first mounting hole 204a of the end cap 20 from the lower plastic 10 to the end cap 20, and pressure is applied to the flange of the first pole 51 to squeeze the first sealing ring 52, so that the first sealing ring 52 is clamped between the first pole 51 and the hole wall of the first mounting hole 204a, and then placed in the injection mold, and injection molding is performed in the injection mold. During the injection molding process, the plastic will flow between the hole wall of the first mounting hole 204a and the first pole 51. After the injection molding is completed, the plastic is demoulded after cooling to form the first upper plastic 53.

[0065] See also Figure 5 and Figure 10 , Figure 10 yes Figure 9 A schematic structural diagram of the first pole 51 in the negative electrode assembly 50 is shown.

[0066] The first pole 51 includes a first end face 511 and a second end face 512. The first end face 511 and the second end face 512 are arranged opposite to each other in the height direction of the first pole 51 (i.e., the thickness direction of the end cover assembly 200). The first end face 511 is oriented in the same direction as the second surface 102 and the fourth surface 202, and the second end face 512 is oriented in the same direction as the first surface 101 and the third surface 201.

[0067] In this embodiment, the first terminal post 51 includes a first columnar portion 513 and a first flange portion 514. The first flange portion 514 is fixedly connected to one side of the first columnar portion 513 in the height direction (i.e., the thickness direction of the end cap assembly 200). Among them, the surface of the first columnar portion 513 facing away from the first flange portion 514 is the second end face 512, and the surface of the first flange portion 514 facing away from the first columnar portion 513 is the first end face 511. Exemplarily, the first columnar portion 513 and the first flange portion 514 can be integrally formed.

[0068] In this embodiment, the first columnar portion 513 passes through the first assembly hole 103a of the lower plastic 10 and the first mounting hole 204a of the end cap 20. The second end face 512 is located on the side of the third surface 201 facing away from the lower plastic 10, and the distance between the second end face 512 and the third surface 201 is the third distance H 3 , the third distance H 3 is less than the first distance H 1 . Exemplarily, H 3 = 3.6 mm.

[0069] The first columnar portion 513 is provided with a first blind hole 515, a first stepped groove 516 and a first annular groove 517. The openings of the first blind hole 515 and the first stepped groove 516 are both located on the second end face 512. The first blind hole 515 and the first stepped groove 516 are both recessed from the second end face 512 in the direction of the first end face 511. Specifically, the first blind hole 515 is located in the middle of the first columnar portion 513. Among them, the central axis of the first blind hole 515 coincides with the central axis of the first columnar portion 513. Exemplarily, the first blind hole 515 can be a tapered hole.

[0070] It should be noted that during the process of machining and forming the first terminal post 51, for example, during the process of cutting a metal block such as an aluminum block to form the first terminal post 51, the first blind hole 515 can play a role in positioning the rotary cutting. Moreover, when multiple energy storage devices 1 are assembled into a module, the first terminal post 51 needs to be welded to connection pieces such as bus bars. The first blind hole 515 can be used for alignment with the through holes on the bus bar. After being confirmed by machine vision recognition, the precise welding of the first terminal post 51 and the connection piece can be realized, ensuring the welding consistency between multiple energy storage devices 1 and the connection piece.

[0071] The first stepped groove 516 is located at the edge of the first cylindrical portion 513, penetrates through the circumferential surface of the first cylindrical portion 513, and is arranged around the circumference of the first cylindrical portion 513. The first annular groove 517 is located on the side of the first stepped groove 516 facing the first flange portion 514, and is arranged at an interval from the first stepped groove 516. The opening of the first annular groove 517 is provided on the circumferential surface of the first cylindrical portion 513. The first annular groove 517 is recessed from the circumferential surface of the first cylindrical portion 513 towards the center of the first cylindrical portion 513. Among them, the first annular groove 517 is arranged around the circumference of the first cylindrical portion 513. During the injection molding of the first upper plastic 53, the design of the first annular groove 517 can increase the contact area between the plastic and the first cylindrical portion 513, and improve the connection stability between the first upper plastic 53 and the first pole 51.

[0072] In addition, the first cylindrical portion 513 is further provided with a first annular structure 518. The first annular structure 518 is arranged on the second end face 512, located between the first blind hole 515 and the first stepped groove 516, and is arranged at an interval from both the first blind hole 515 and the first stepped groove 516. The first annular structure 518 is arranged around the first blind hole 515. Among them, there are multiple first annular structures 518, and along the direction from the center axis of the first cylindrical portion 513 to the edge (i.e., the direction from the center axis of the first pole 51 to the edge), the multiple first annular structures 518 are arranged at intervals in sequence. Exemplarily, the multiple first annular structures 518 are concentric rings. Among them, the width of each first annular structure 518 is w 1 , and the height of the first annular structure 518 is h 1 , and the distance between two adjacent first annular structures 518 is w 2 . Exemplarily, w 1 = 0.02mm, h 1 = 0.1mm, w 2 = 0.05mm.

[0073] It should be noted that the design of the first annular structure 518 can prevent the second end face 512 of the first pole 51 from being contaminated. Fine debris particles can fall into the gap between two adjacent first annular structures 518. When the first pole 51 and connecting pieces such as the bus bar are welded by laser penetration welding, the laser energy can be better conducted to the second end face 512 of the first pole 51, melting the first annular structure 518. At the same time, the first annular structure 518 can surround the molten metal of the connecting pieces such as the bus bar above it that is melted by laser heating, restrict its outward or inward diffusion and gather in the welding area. The molten metal can fill the gap between two adjacent first annular structures 518, increasing the welding area and making the welding between the bus bar and the second end face 512 of the first pole 51 more firm. In addition, the first annular structure 518 can wrap the molten metal in the welding area, avoiding its outward spread, which may cause uneven stress distribution of the annular welding lines and result in warping of the connecting piece.

[0074] The first flange portion 514 is received in the first avoidance groove 104a of the lower plastic 10. The first end face 511 is located on the side of the second surface 102 away from the first surface 101, and the distance between the first end face 511 and the second surface 102 is the second distance H 2 , the second distance H 2 and the third distance H 3 The sum is less than the first distance H 1 . Exemplarily, H 2 = 0.6 mm.

[0075] It should be noted that the first end face 511 of the first pole column 51 protrudes from the second surface 102 of the lower plastic 10, which can ensure that when the first pole column 51 is welded to the first adapter plate (not shown in the figure), the burrs around the rhombus indentation formed by ultrasonic welding of the first adapter plate on the first end face 511 will not be scraped by the lower plastic 10, causing the metal burrs to fall off, preventing internal short circuit of the energy storage device 1, and ensuring the installation reliability of the energy storage device 1.

[0076] Please refer to Figure 11 , Figure 11 which Figure 10 is the schematic cross-sectional structure diagram of the first pole column 51 shown after being cut along B-B.

[0077] The first pole column 51 includes a first metal portion 51a and a second metal portion 51b. The second metal portion 51b is fixedly connected to one side of the first metal portion 51a in the height direction. The first metal portion 51a and the part of the second metal portion 51b close to the first metal portion 51a form the first column portion 513, and the part of the second metal portion 51b away from the first metal portion 51a forms the first flange portion 514. Among them, the first metal portion 51a can be made of aluminum, and the second metal portion 51b can be made of copper.

[0078] Please refer to Figure 5 and Figure 10 , the first sealing ring 52 is sleeved on the first column portion 513 and abuts against the first flange portion 514. Specifically, the first sealing ring 52 is sleeved on the part of the first column portion 513 close to the first flange portion 514 and is clamped between the first pole column 51 and the end cover 20. The surface of the first sealing ring 52 facing the first flange portion 514 abuts against the surface of the first flange portion 514 facing the first column portion 513. Among them, part of the first sealing ring 52 is clamped between the first column portion 513 and the hole wall of the first mounting hole 204a, and part of the first sealing ring 52 is clamped between the first flange portion 514 and the bottom wall of the first avoidance groove 104a.

[0079] The first upper plastic 53 is sleeved on the first cylindrical portion 513, connected between the first cylindrical portion 513 and the end cap 20, and covers the groove wall surface of the first annular groove 517. The surface of the first upper plastic 53 facing away from the end cap 20 is located on the side of the second end face 512 facing the end cap 20. In other words, the second end face 512 is located on the side of the surface of the first upper plastic 53 facing away from the end cap 20 and facing away from the end cap 20. The distance between the second end face 512 and the surface of the first upper plastic 53 facing away from the end cap 20 is H 5 . Exemplarily, H 5 = 0.8 mm. In addition, the surface of the first upper plastic 53 facing away from the end cap 20 may be flush with the bottom wall surface of the first stepped groove 516, or the surface of the first upper plastic 53 facing away from the end cap 20 is located on the side of the bottom wall surface of the first stepped groove 516 facing the end cap 20.

[0080] It should be noted that the second end face 512 of the first pole column 51 protrudes from the surface of the first upper plastic 53 facing away from the end cap 20. When welding connection pieces such as the bus bar, the second end face 512 is not likely to interfere with the first upper plastic 53 and cause false soldering, which affects the welding reliability. At the same time, when the first upper plastic 53 is formed by injection molding, the mold can be sleeved on the first stepped groove 516 of the first pole column 51 to prevent the molten plastic liquid from overflowing to the second end face 512 of the first pole column 51. In addition, when welding connection pieces such as the bus bar, the heat conduction of the welding causes the joint between the first upper plastic 53 and the first pole column 51 to melt. When it becomes liquid, the plastic liquid will not flow to the second end face 512 of the first pole column 51 to affect the reliable electrical connection between the first pole column 51 and connection pieces such as the bus bar.

[0081] In addition, the first upper plastic 53 is further provided with a first identification groove 531, and the opening of the first identification groove 531 is located on the surface of the first upper plastic 53 facing away from the end cap 20. The first identification groove 531 is recessed in the direction from the surface of the first upper plastic 53 facing away from the end cap 20 towards the end cap 20. Among them, there are two first identification grooves 531, and the two first identification grooves 531 are respectively located on the opposite sides of the first upper plastic 53. Exemplarily, the first identification groove 531 is in the shape of a "one" character. In some other embodiments, the first identification groove 531 may also be in the shape of a "negative" character or other shapes.

[0082] Please refer to Figure 10 and Figure 12 , Figure 12 which Figure 3 is a schematic structural diagram of the end cap assembly 200 shown from another angle.

[0083] In this embodiment, the end cap assembly 200 further includes a protective film 70, and the protective film 70 is installed on the second surface 102 and covers the first end face 511 of the first pole column 51. The thickness of the protective film 70 is the fourth distance H 4 , the fourth distance H4 and the second distance H 2 and the third distance H 3 the sum of which is less than the first distance H 1 . Exemplarily, H 4 = 0.05 mm.

[0084] It should be noted that since the first pole column 51 is made of metal materials such as copper and aluminum, it is prone to oxidation when exposed to air for a long time, and an oxide film layer with poor conductivity will be formed on its surface. After the end cover assembly 200 is manufactured, a protective film 70 will be attached to the first end face 511 to slow down the oxidation rate of the first pole column 51 and prevent the first end face 511 from being soiled.

[0085] It should be understood that when multiple end cover assemblies 200 are transported, they are often stacked. Due to the thickness H of the protective film 70 4 and the second distance H 2 and the third distance H 3 the sum of which is less than the first distance H 1 , the second end face 512 of the first pole column 51 in the end cover assembly 200 will not abut against the first end face 511 of the first pole column 51 in the previous end cover assembly 200, preventing the surface of the second end face 512 of the first pole column 51 from being scratched to generate peeled metal debris or contaminating the second end face 512 of the first pole column 51, thereby affecting the welding effect of the first pole column 51 and connection pieces such as the tabs of the energy storage device module. At the same time, not only can it prevent the second end face 512 of the first pole column 51 from scratching the first end face 511 of the first pole column 51 in the previous end cover assembly 200 to cause surface scratches and generate metal burrs when multiple end cover assemblies 200 are stacked, avoiding the metal burrs falling off into the internal winding electrode assembly of the energy storage device 1 during the subsequent assembly of the end cover assembly 200 to the housing 100 and causing a short circuit, but also can prevent the second end face 512 of the first pole column 51 from scratching the protective film 70 of the previous end cover assembly 200 and causing the protective film 70 to fall off, resulting in the protective film 70 being unable to protect the first end face 511 of the first pole column 51.

[0086] Please refer to Figure 5 and Figure 13 , Figure 13 which is Figure 4 the exploded structural schematic diagram of the positive electrode assembly 60 in the end cover assembly 200 shown.

[0087] The positive electrode assembly 60 includes a second pole column 61, a second sealing ring 62, and a second upper plastic 63. The second pole column 61 passes through the second assembly hole 103b of the lower plastic 10 and the second installation hole 204b of the end cap 20. Both the second upper plastic 63 and the second sealing ring 62 are sleeved on the second pole column 61, and the second pole column 61 and the end cap 20 are isolated to insulate the second pole column 61 from the end cap 20. The second upper plastic 63 is located on the side of the second sealing ring 62 away from the lower plastic 10.

[0088] Among them, the structures of the second pole column 61, the second sealing ring 62, and the second upper plastic 63, as well as the cooperation relationships between any two of them, can all refer to the relevant descriptions of the first pole column 51, the first sealing ring 52, the first upper plastic 53, and the first adapter plate in the above text, and will not be elaborated here. The difference between the positive electrode assembly 60 and the negative electrode assembly 50 is that the second pole column 61 can be made of aluminum material. In the second upper plastic 63, the second identification groove 631 is in a "cross" shape. In some other embodiments, the second identification groove 631 can also be in a "plus" shape or other shapes.

[0089] Please refer to Figure 14 and Figure 15 , Figure 14 is Figure 2 the schematic structural diagram of the end cap assembly 200 in the second embodiment of the energy storage device 1 shown in Figure 15 is Figure 14 the partial structural schematic diagram of the end cap assembly 200 shown in Figure 15 not shown Figure 14 the protective film 70 in

[0090] The difference between the end cap assembly 200 shown in this embodiment and the end cap assembly 200 shown in the above first embodiment is that the lower plastic 10 is further provided with two protrusions 13. The two protrusions 13 are provided on the second surface 102 and are located on the side of the boss 12 facing the first pole column 51. Specifically, both of the two protrusions 13 abut against the boss 12. Along the width direction of the lower plastic 10, the two protrusions 13 are respectively located on opposite sides of the first end face 511 of the first pole column 51 and are both spaced apart from the first end face 511 of the first pole column 51. Exemplarily, the protrusion 13 is trapezoidal.

[0091] Among them, each protrusion 13 includes a third end face 131 and a side face 132. The third end face 131 is the surface of the protrusion 13 away from the second surface 102, and is located on the side of the surface of the boss 12 away from the second surface 102 facing the second surface 102, and the distance from the second surface 102 is H 6 , along the width direction of the lower plastic 10, the distance between the two protrusions 13 is w 3 , the width of the first end face 511 is w 4 . Exemplarily, H 6=4.65mm, w 3 =32mm, w 4 =27mm.

[0092] In addition, the side surface 132 is an inclined surface. The protective film 70 also covers the side surfaces 132 of the two protrusions 13, and a gap 133 is formed between the second surfaces 102. When multiple end cap assemblies 200 are stacked for transportation, in the next layer of end cap assemblies 200, the first pole 51 and the first upper plastic 53 that protrude from the third surface 201 of the end cap 20 can be snapped into the upper layer of end cap assemblies 200, between the boss 12 of the lower plastic 10 and the two protrusions 13, so that the stacked multiple end cap assemblies 200 remain in a columnar shape to prevent them from tipping over. At the same time, it is also convenient for the claws of automated production to clamp the end cap assemblies 200 for transportation to the next process. Furthermore, the protrusion 13 increases the structural strength of the boss 12 in the width direction, preventing the risk of the boss 12 being pulled downward by the mylar sheet and being bent and deformed after the energy storage device 1 is used for a long time. Furthermore, when the first end surface 511 is welded to the adapter sheet, the gap 133 between the protective film 70 and the second surface 102 can facilitate the removal of the protective film 70 , thereby improving the assembly efficiency of the energy storage device 1 .

[0093] The present application also provides an electric device, which includes the energy storage device 1, and the energy storage device 1 supplies power to the electric device. The electric device may be a new energy vehicle, a power storage station, a server, or other equipment that requires electricity.

[0094] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application; in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An end cap assembly for an energy storage device, characterized in that, it includes an end cap, a lower plastic, and a terminal post. The end cap is provided with a mounting hole that penetrates the end cap along the thickness direction of the end cap. The end cap includes a third surface facing away from the lower plastic. The lower plastic is mounted on one side in the thickness direction of the end cap. The lower plastic includes a first surface and a second surface. Along the thickness direction of the end cap assembly, the first surface and the second surface are arranged opposite to each other. The lower plastic is provided with an assembly hole that penetrates the first surface and the second surface along the thickness direction of the lower plastic and is communicated with the mounting hole. The lower plastic is further provided with a boss. The boss is arranged in the edge area of the second surface and is spaced from the assembly hole. The distance between the surface of the boss facing away from the second surface and the second surface is a first distance; the terminal post passes through the assembly hole and the mounting hole. The terminal post includes a first end face facing the same direction as the second surface and a second end face opposite to the first end face. The first end face is located on the side of the second surface facing away from the first surface and the distance between the first end face and the second surface is a second distance. The second end face is located on the side of the third surface facing away from the second surface and the distance between the second end face and the first surface is a third distance. The sum of the second distance and the third distance is less than the first distance.

2. The end cap assembly according to claim 1, characterized in that, the end cap assembly further includes a protective film. The protective film is mounted on the second surface and covers the first end face.

3. The end cap assembly according to claim 2, characterized in that, the thickness of the protective film is a fourth distance, and the first distance is greater than the sum of the second distance, the third distance, and the fourth distance.

4. The end cap assembly according to any one of claims 1 to 3, characterized in that, the end cap assembly further includes an upper plastic. The upper plastic is connected between the terminal post and the end cap. The surface of the upper plastic facing away from the end cap is located on the side of the second end face facing the first surface.

5. The end cap assembly according to claim 4, characterized in that, the terminal post is provided with a stepped groove. The opening of the stepped groove is located on the second end face. The stepped groove penetrates the circumferential surface of the terminal post and surrounds the terminal post. The bottom wall surface of the stepped groove is located on the side of the surface of the upper plastic facing away from the end cap and facing away from the second end face, or the bottom wall surface of the stepped groove is flush with the surface of the upper plastic facing away from the end cap.

6. The end cap assembly according to any one of claims 1 to 3, characterized in that, the terminal post is provided with a blind hole. The opening of the blind hole is located on the second end face. The central axis of the blind hole coincides with the central axis of the terminal post.

7. The end cap assembly according to claim 6, characterized in that, The terminal post is further provided with a plurality of annular structures, each of the annular structures is arranged on the second end face, surrounds the blind hole, and is arranged at an interval from the blind hole, and the plurality of annular structures are arranged at intervals in sequence along the direction from the center axis of the terminal post to the edge.

8. The end cap assembly according to claim 1, wherein, the lower plastic is further provided with two protrusions, both of the protrusions are arranged on the second surface and on one side of the boss facing the terminal post, and along the width direction of the end cap assembly, the two protrusions are respectively located on opposite sides of the first end face and are arranged at an interval from the first end face; both of the protrusions abut against the surface of the boss facing the terminal post, and each of the protrusions includes a third end face facing away from the second surface, and the third end face is located between the surface of the boss facing away from the second surface and the second surface.

9. The end cap assembly according to claim 8, wherein, each of the protrusions includes an inclined surface facing away from the boss, the end cap assembly further includes a protective film, the protective film covers the first end face and the inclined surfaces of the two protrusions, and a gap is formed between the protective film and the second surface.

10. An energy storage device, wherein, comprising a housing and the end cap assembly according to any one of claims 1 to 9, the housing is provided with an opening, and the end cap assembly is installed on the housing and closes the opening.

11. An electrical equipment, wherein, comprising the energy storage device according to claim 10, and the energy storage device supplies power to the electrical equipment.

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