Energy storage devices and electrical equipment

Abstract

The present application discloses an energy storage device and an electrical device. The energy storage device includes an end cap assembly, which includes an end cap, a lower plastic and an explosion-proof valve. The end cap is provided with an explosion-proof hole, which penetrates the end cap along the thickness direction of the end cap assembly and is offset; the lower plastic includes a lower plastic body, which is provided with a vent hole, which penetrates the lower plastic body along the thickness direction of the end cap assembly and is offset; the lower plastic body is stacked on the end cap, and the vent hole and the explosion-proof hole are opposite and connected. The present application can increase the exhaust speed of the energy storage device.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an energy storage device and electrical equipment. Background Art

[0002] Secondary batteries, also known as rechargeable batteries or storage batteries, refer to batteries that can be recharged to activate the active materials and continue to be used after the battery is discharged. The recyclable nature of secondary batteries has made them gradually become the main power source for electrical equipment. As the demand for secondary batteries gradually increases, people's performance requirements for them in various aspects are also getting higher and higher, especially the requirements for battery life and safety performance. Secondary batteries are usually provided with explosion-proof holes, and explosion-proof valves are provided in the explosion-proof holes. When the secondary battery is thermally runaway, a large amount of gas is generated in the secondary battery. A large amount of gas flows to the explosion-proof hole, and breaks the explosion-proof valve to escape to the outside of the secondary battery to reduce the internal air pressure of the secondary battery and ensure the safety performance of the secondary battery. In the prior art, the explosion-proof hole is usually located in the middle of the length direction of the secondary battery. When a large amount of gas reaches the explosion-proof hole, it will produce a counter-flow of airflow, resulting in a decrease in the airflow velocity, which in turn leads to a decrease in the exhaust speed of the secondary battery. Summary of the invention

[0003] The present application provides an energy storage device and electrical equipment, which can increase the exhaust speed of the energy storage device.

[0004] In a first aspect, the present application provides an energy storage device, including an end cover assembly, the end cover assembly including an end cover, a lower plastic and an explosion-proof valve, the end cover is provided with an explosion-proof hole, along the thickness direction of the end cover assembly, the explosion-proof hole penetrates the end cover, the end cover includes a first end face and a second end face arranged opposite to the first end face, along the length direction of the end cover assembly, the explosion-proof hole is located between the first end face and the second end face, the distance between the hole axis of the explosion-proof hole and the first end face is smaller than the distance between the hole axis of the explosion-proof hole and the second end face, and the explosion-proof valve is installed on the hole wall of the explosion-proof hole;

[0005] The lower plastic comprises a lower plastic body, the lower plastic is provided with a vent hole, and along the thickness direction of the end cover assembly, the vent hole penetrates the lower plastic body, the lower plastic body comprises a first side surface and a second side surface arranged opposite to the first side surface, along the length direction of the end cover assembly, the vent hole is located between the first side surface and the second side surface, and the distance between the hole axis of the vent hole and the first side surface is smaller than the distance between the vent hole and the second side surface;

[0006] The lower plastic body is stacked on the end cover, and along the length direction of the end cover assembly, the first side surface and the first end surface are oriented in the same direction, the second side surface and the second end surface are oriented in the same direction, and the explosion-proof hole is opposite to and connected to the vent hole.

[0007] In a possible implementation, the energy storage device further includes a shell, an electrode assembly, a first adapter plate, and a second adapter plate, the shell is provided with an opening and a receiving cavity, and along the height direction of the energy storage device, the opening is located at one end of the receiving cavity and is communicated with the receiving cavity;

[0008] The electrode assembly comprises a winding core, a first pole lug and a second pole lug, and along the length direction of the energy storage device, the first pole lug and the second pole lug are respectively connected to two surfaces of the winding core that are arranged in opposite directions;

[0009] The electrode assembly is accommodated in the accommodating cavity, the first pole ear and the second pole ear are both facing the side wall of the accommodating cavity, the end cover seals the opening, the lower plastic is accommodated in the accommodating cavity, and along the height direction of the energy storage device, the lower plastic is located between the electrode assembly and the end cover, one end of the first adapter sheet is located between the first pole ear and the side wall of the accommodating cavity and is electrically connected to the first pole ear, the other end of the first adapter sheet is bent and located between the lower plastic and the electrode assembly, one end of the second adapter sheet is located between the second pole ear and the side wall of the accommodating cavity and is electrically connected to the second pole ear, and the other end of the second adapter sheet is bent and located between the lower plastic and the electrode assembly.

[0010] In a possible implementation manner, a ratio of a distance L2 between the hole axis of the explosion-proof hole and the second end surface to a distance L1 between the explosion-proof hole and the first end surface is in the range of 1<L2 / L1≤4.

[0011] In a possible implementation manner, the lower plastic body includes a first surface and a second surface disposed opposite to the first surface, the first surface and the second surface are connected between the first side surface and the second side surface, the lower plastic is further provided with a sink groove, the sink groove is recessed from the second surface to the first surface, along the length direction of the end cover assembly, the sink groove is located between the first side surface and the second side surface, the sink groove includes two groove side walls and a groove bottom wall connected between the two groove side walls, and along the thickness direction of the end cover assembly, the vent hole penetrates the groove bottom wall of the sink groove;

[0012] The lower plastic also includes a first protrusion, which is protruded from the surface of the bottom wall of the sink. Along the length direction of the end cover assembly, the first protrusion is located between the vent hole and the first side surface. Along the width direction of the end cover assembly, the first protrusion is spaced apart from the two side walls of the sink.

[0013] In a possible embodiment, the lower plastic also includes a second protrusion, which is protruding from the surface of the bottom wall of the trough. Along the length direction of the end cover assembly, the second protrusion is located between the vent hole and the second side surface. Along the width direction of the lower plastic, the second protrusion is spaced apart from the two side walls of the trough.

[0014] In a possible implementation manner, a ratio of a width d1 of the first protrusion to a width w of the recess is in the range of 0.7≤d1 / w≤0.9, and a ratio of a width d2 of the second protrusion to a width w of the recess is in the range of 0.6≤d2 / w≤0.8.

[0015] In a possible implementation, along the length direction of the end cover assembly, the distance between the first protrusion and the hole axis of the vent hole is less than or equal to 25 mm, and the distance between the second protrusion and the hole axis of the vent hole is less than or equal to 30 mm.

[0016] In a possible implementation manner, along the thickness direction of the end cover assembly, the first protrusion and the second protrusion both protrude from the sink groove, and the height of the first protrusion is equal to the height of the second protrusion;

[0017] Along the height direction of the energy storage device, the sink groove faces the electrode assembly, and the first protrusion and the second protrusion are both in contact with the winding core.

[0018] In a possible implementation manner, the lower plastic further includes a third protrusion, the third protrusion is protruding from the surface of the bottom wall of the sink, and along the thickness direction of the end cover assembly, the height of the third protrusion is less than the height of the first protrusion;

[0019] Along the length direction of the end cover assembly, the third protrusion is located between the first protrusion and the first side surface, and the distance between the third protrusion and the first protrusion is less than or equal to 25 mm. Along the width direction of the lower plastic, the third protrusion is spaced apart from the two side walls of the groove, and the ratio of the width d3 of the third protrusion to the width w of the groove is in the range of: 0.7≤d3 / w≤0.9.

[0020] In a possible implementation manner, the lower plastic further includes a fourth protrusion, the fourth protrusion is protruding from the surface of the bottom wall of the sink, and along the thickness direction of the end cover assembly, the height of the fourth protrusion is less than the height of the second protrusion;

[0021] Along the length direction of the end cover assembly, the fourth protrusion is located between the second protrusion and the second side surface, and along the width direction of the end cover assembly, the fourth protrusion is spaced apart from the two side walls of the groove, and the ratio range of the width d4 of the fourth protrusion to the width w of the groove is: 0.7≤d4 / w≤0.9.

[0022] In a possible implementation manner, the volume of the first protrusion is equal to the volume of the second protrusion, and the volume of the third protrusion is equal to the volume of the fourth protrusion;

[0023] The lower plastic also includes a fifth protrusion, which is protruded from the surface of the bottom wall of the sink, and is located between the second protrusion and the fourth protrusion along the length direction of the end cover assembly. The fifth protrusion is spaced apart from the second protrusion and the fourth protrusion, and the height of the fifth protrusion is less than the height of the second protrusion along the thickness direction of the end cover assembly;

[0024] Along the width direction of the lower plastic, the fifth protrusion is spaced apart from the two side walls of the sink, and the ratio of the width d5 ​​of the fifth protrusion to the width w of the sink is in the range of 0.7≤d5 / w≤0.9.

[0025] In a possible implementation manner, the end cover is provided with a liquid injection hole, which penetrates the end cover along the thickness direction of the end cover assembly, and the lower plastic further includes a liquid injection through hole, which penetrates the first surface and the second surface along the thickness direction of the lower plastic, and is located between the fourth protrusion and the fifth protrusion along the length direction of the lower plastic;

[0026] Along the thickness direction of the end cover assembly, the injection hole is opposite to and connected with the injection through hole.

[0027] In a possible implementation manner, the lower plastic further includes two convex ribs, both of which are convexly arranged on the second surface, and along the width direction of the end cover assembly, the two convex ribs are respectively connected to opposite sides of the lower plastic body, and along the length direction of the end cover assembly, the lengths of the two convex ribs are equal to the length of the lower plastic body, and along the thickness direction of the end cover assembly, the two convex ribs are protruding from the first protrusion;

[0028] Along the width direction of the energy storage device, the two convex ribs are respectively located on opposite sides of the electrode assembly, and the two convex ribs are spaced apart from the electrode assembly.

[0029] In a possible implementation manner, the lower plastic includes a limiting convex portion, and along the thickness direction of the end cover assembly, the sink groove is convexly provided on the first surface to form the limiting convex portion, and the limiting convex portion includes a concave surface;

[0030] The lower plastic is further provided with a first groove and a second groove, wherein the first groove is concavely provided on the surface of the groove bottom wall of the sink groove facing the concavely provided, and the first protrusion is convexly provided on the surface of the groove bottom wall of the sink groove, and the second groove is concavely provided on the surface of the groove bottom wall of the sink groove facing the concavely provided, and the second protrusion is convexly provided on the surface of the groove bottom wall of the sink groove;

[0031] The end cover further includes a first mounting surface and a second mounting surface arranged opposite to the first mounting surface, the end cover is provided with a mounting groove, along the thickness direction of the end cover, the mounting groove is concavely arranged from the second mounting surface to the first mounting surface, and convexly arranged on the first mounting surface to form a convex bump, the convex bump includes a stamping surface, and the explosion-proof hole penetrates the bottom wall of the mounting groove;

[0032] The end cover is provided with a first recess and a second recess, the first recess is recessed by the punching surface facing the groove bottom wall of the mounting groove, and a first protrusion is convexly provided on the surface of the groove bottom wall of the mounting groove, and the shape of the first protrusion matches the first groove, the second recess is recessed by the punching surface facing the groove bottom wall of the mounting groove, and a second protrusion is convexly provided on the surface of the groove bottom wall of the mounting groove, and the shape of the second protrusion matches the second groove;

[0033] The limiting protrusion is limited in the installation groove, the first protrusion is limited in the first groove, and the second protrusion is limited in the second groove.

[0034] In a possible implementation manner, the first protrusion includes a first sub-protrusion and a second sub-protrusion, the second sub-protrusion is convexly arranged on a surface of the first sub-protrusion facing away from the first mounting surface, and along the thickness direction of the end cover assembly, the orthographic projection of the second sub-protrusion on the first surface is located within the orthographic projection of the first sub-protrusion;

[0035] The second protrusion includes a third sub-protrusion and a fourth sub-protrusion. The fourth sub-protrusion is protruding from the surface of the third sub-protrusion facing away from the first mounting surface. Along the thickness direction of the end cover assembly, the orthographic projection of the fourth sub-protrusion on the first mounting surface is located within the orthographic projection of the third sub-protrusion.

[0036] In a possible implementation, the lower plastic includes a first lower plastic and a second lower plastic, the first side surface is located on the first lower plastic, the second side surface is located on the second lower plastic, and along the length direction of the end cover assembly, the vent hole is located at an end of the second lower plastic away from the second side surface, and the end of the first lower plastic away from the first side surface is opposite to the end of the second lower plastic away from the second side surface.

[0037] In a second aspect, the present application provides an electrical device, comprising the energy storage device as described above, wherein the energy storage device is used to store electrical energy.

[0038] The beneficial effect of the present application is that: along the length direction of the end cap assembly, the vents and the explosion-proof holes are offset, and the vents and the explosion-proof holes are opposite and connected. When the energy storage device is thermally runaway, the gas generated in the electrode assembly diffuses to the surroundings, and finally discharges the energy storage device through the vents and the explosion-proof holes in sequence. The gas flow generated between the first side and the vent is less than the gas flow generated between the second side and the vent. Therefore, along the length direction of the end cap assembly, the gas flow to the vent on both sides of the vent is unbalanced. Compared with the prior art in which the vent is set in the middle position of the energy storage device, the gas flow on both sides of the vent is balanced. In the present application, the turbulent kinetic energy and turbulent dissipation generated by the gas on both sides of the vent at the vent are small, which can reduce the mutual impact of the gas on both sides of the vent, reduce the pressure loss of the gas at the vent, and thus speed up the gas to pass through the vent of the lower plastic and then through the explosion-proof hole of the end cap to discharge the energy storage device. That is to say, in the present application, by offsetting the vent holes and the explosion-proof holes, the exhaust speed of the energy storage device can be increased, thereby improving the safety performance of the energy storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the implementation manner will be briefly introduced below. Obviously, the drawings described below are only some implementation manners of the present application. For ordinary technicians in this field, other drawings can be obtained like these drawings without paying any creative work.

[0040] Figure 1 An application scenario diagram of the energy storage device provided in the embodiment of the present application;

[0041] Figure 2 for Figure 1 A schematic diagram of the structure of the energy storage device shown;

[0042] Figure 3 for Figure 2 A schematic diagram of the exploded structure of the energy storage device shown;

[0043] Figure 4 for Figure 3 A schematic diagram of the assembly structure of the electrode assembly and the adapter assembly shown;

[0044] Figure 5 for Figure 3 A schematic diagram of an exploded structure of an end cover assembly of the energy storage device shown in one angle;

[0045] Figure 6 for Figure 5 A schematic diagram of the exploded structure of the end cover assembly shown in another angle;

[0046] Figure 7 for Figure 5 A schematic diagram of the structure of the first lower plastic at one angle is shown;

[0047] Figure 8 for Figure 7 A schematic structural diagram of the first lower plastic at another angle;

[0048] Fig. 9 for Figure 5 A schematic diagram of the structure of the second lower plastic at one angle is shown;

[0049] Fig.10 for Fig. 9 A schematic diagram of the structure of the second lower plastic at another angle;

[0050] Fig.11a for Figure 5 A cross-sectional schematic diagram of the assembly structure of the end cover, the first lower plastic, and the second lower plastic;

[0051] Fig.11b for Fig.11a An enlarged schematic diagram of part A of the assembly structure of the end cover, the first lower plastic, and the second lower plastic;

[0052] Fig.11c for Fig.11a An enlarged schematic diagram of part B of the assembly structure of the end cover, the first lower plastic, and the second lower plastic;

[0053] Fig.12a for Figure 2 A schematic diagram of the cross-sectional structure of the energy storage device shown;

[0054] Figure 12b for Fig.12a An enlarged schematic diagram of part C of the energy storage device shown;

[0055] Fig.12c for Fig.12a An enlarged schematic diagram of part D of the energy storage device shown.

[0056] Description of reference numerals:

[0057] 5000-energy storage system, 4100-first electric energy conversion device, 4200-second electric energy conversion device, 3000-first electric equipment, 2000-second electric equipment, 1000-energy storage device, 400-shell, 300-electrode assembly, 200-transfer plate assembly, 100-end cover assembly, 210-first transfer plate, 220-second transfer plate, 51-first pole, 52-second pole, 330-winding core, 310-first pole ear, 320-second pole ear, 3301-first immersion Wetting surface, 3302-second wetting surface, 60-end cover, 30-lower plastic, 40-explosion-proof valve, 10-first lower plastic, 20-second lower plastic, 11-first lower plastic body, 111-first top surface, 112-first bottom surface, 118-first side surface, 218-second side surface, 113-first pole through hole, 114-first sink groove, 12-first limiting convex portion, 121-first concave surface, 14-first groove, 15-third groove, 141-first sub-groove, 142-second sub-groove, 161 -first sub-protrusion, 1611-first surface, 162-second sub-protrusion, 16-first protrusion, 17-third protrusion, 18-first rib, 19-second rib, 21-second lower plastic body, 211-second top surface, 212-second bottom surface, 213-second pole through hole, 214-second sink groove, 22-second limiting convex portion, 221-second concave surface, 216-ventilation hole, 23-explosion-proof fence, 231-ventilation hole, 24-second groove, 25-fourth groove, 241-third sub-groove, 242-fourth sub-groove, 261-third sub-protrusion, 2611-second surface, 262-fourth sub-protrusion, 26-second protrusion, 27-fourth protrusion, 201-fifth groove, 202-fifth protrusion, 217-liquid injection through hole, 28-third rib, 29-fourth rib, 33-rib, 611-first mounting surface, 612-second mounting surface, 618-first end surface, 619-second end surface, 613-first through hole, 614-second through hole, 615-mounting groove, 62-convex hull, 621 -stamping surface, 616-explosion-proof hole, 617-liquid injection hole, 641-first recess, 651-second recess, 661-fourth recess, 671-fifth recess, 642-first convex, 652-second convex, 662-fourth convex, 672-fifth convex, 511-first flange, 512-first column, 521-second flange, 522-second column, 31-lower plastic body, 311-first surface, 312-second surface, 314-sunk groove, 32-limiting convex, 321-concave surface. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0059] Since the energy people need is highly temporal and spatial, in order to rationally utilize energy and improve energy utilization, it is necessary to use a medium or device to store one form of energy in the same form or convert it into another form of energy, and then release it in a specific form of energy based on future application needs. At present, the generation of green electricity generally relies on photovoltaics, wind power, water potential, etc., while wind and solar energy generally have problems of strong intermittency and large volatility, which will cause instability of the power grid, insufficient electricity during peak hours, too much electricity during low hours, and unstable voltage will also cause damage to electricity. Therefore, it may cause "wind and light abandonment" problems due to insufficient electricity demand or insufficient grid acceptance capacity. To solve these problems, energy storage must be relied on. That is, electrical energy is converted into other forms of energy by physical or chemical means and stored, and energy is converted into electrical energy and released when needed. In simple terms, energy storage is similar to a large "power bank". When photovoltaic and wind energy are sufficient, electrical energy is stored and the stored electricity is released when needed.

[0060] Taking electrochemical energy storage as an example, the present application provides an energy storage device 1000, which has a group of chemical batteries inside. The energy storage device 1000 mainly uses the chemical elements in the chemical batteries as energy storage media. The charging and discharging process is accompanied by chemical reactions or changes in the energy storage media. Simply put, the electricity generated by wind energy and solar energy is stored in chemical batteries. When the use of external electricity reaches a peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0061] At present, energy storage application scenarios are quite extensive, including power generation side energy storage, grid side energy storage, base station side energy storage and user side energy storage. The corresponding types of energy storage devices 1000 include:

[0062] Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, achieve load matching of electric energy in time and space, enhance the ability to absorb renewable energy, and are of great significance in grid system backup, relieving peak load power supply pressure, and peak and frequency regulation.

[0063] The main operating mode of small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios on the user side is "peak shaving and valley filling". Since there is a large price difference in electricity charges at peak and valley locations according to electricity demand, after users have energy storage equipment, in order to reduce costs, they usually charge the energy storage cabinets / boxes during the low electricity price period; during the peak electricity price period, the electricity in the energy storage equipment is discharged for use to achieve the purpose of saving electricity bills.

[0064] It should be noted that the above-mentioned energy storage containers, small and medium-sized energy storage cabinets, household small energy storage boxes and other equipment containing the energy storage device 1000 can be understood as electrical equipment.

[0065] See also Figure 1 , Figure 1 : is an application scenario diagram of the energy storage device provided in the embodiment of the present application. The energy storage device 1000 provided in the embodiment of the present application is applied to an energy storage system 5000, and the energy storage system 5000 includes a first electric energy conversion device 4100, a second electric energy conversion device 4200, a first electric device 3000, a second electric device 2000 and an energy storage device 1000. The energy storage system 5000 also includes an energy storage cabinet, and the energy storage device 1000 is installed in the energy storage cabinet, and the energy storage cabinet can be installed outdoors. Specifically, the first electric energy conversion device 4100 can convert solar energy into electric energy during the period of low electricity prices, and the energy storage device 1000 is used to store the electric energy and supply the first electric device 3000 or the second electric device 2000 during peak electricity consumption, or to supply power when the first electric device 3000 or the second electric device 2000 is powered off / power outage. The second power conversion device 4200 can convert wind energy into electric energy, and the energy storage device 1000 is used to store the electric energy and supply it to the first power device 3000 or the second power device 2000 during peak power consumption, or to supply power when the first power device 3000 or the second power device 2000 is powered off / out of power. The transmission of electric energy can be carried out using a high-voltage cable.

[0066] It should be noted that the first electric device 3000 , the second electric device 2000 and other devices including the energy storage device 1000 can be understood as electric devices.

[0067] There may be several energy storage devices 1000, which are connected in series or in parallel. In this embodiment, "several" means two or more.

[0068] It is understandable that the energy storage device 1000 may include but is not limited to a single cell, a battery module, a battery pack, a battery system, etc. The actual application form of the energy storage device 1000 provided in the embodiment of the present application may be but is not limited to the listed products, and may also be other application forms. The embodiment of the present application does not strictly limit the application form of the energy storage device 1000. The embodiment of the present application only takes the energy storage device 1000 as a multi-core battery as an example for explanation.

[0069] Please refer to Figure 2 , Figure 3 and Figure 4 , Figure 2 for Figure 1 The schematic diagram of the structure of the energy storage device 1000 is shown in FIG. Figure 3 for Figure 2 The schematic diagram of the exploded structure of the energy storage device 1000 is shown; Figure 4 for Figure 3 Schematic diagram of the assembly structure of the electrode assembly and the adapter assembly.

[0070] The energy storage device 1000 includes a shell 400, an electrode assembly 300, a transfer sheet assembly 200 and an end cap assembly 100. The shell 400 has an opening and is provided with a receiving cavity. The electrode assembly 300 is received in the receiving cavity. The end cap assembly 100 is mounted on one end of the electrode assembly 300 and is sealed at the opening. The transfer sheet assembly 200 includes a first transfer sheet 210 and a second transfer sheet 220. The first transfer sheet 210 electrically connects the electrode assembly 300 and the first pole 51 of the end cap assembly 100, and the second transfer sheet 220 electrically connects the electrode assembly 300 and the second pole 52 of the end cap assembly 100.

[0071] The electrode assembly 300 includes a winding core 330 and a pole ear. The winding core 330 includes a first wetted surface 3301 and a second wetted surface 3302. The first wetted surface 3301 and the second wetted surface 3302 are arranged in opposite directions along the width direction of the electrode assembly 300. The first wetted surface 3301 and the second wetted surface 3302 are both the two surfaces with the largest area of ​​the winding core 330, that is, the large surface of the electrode assembly 300. The pole ear includes a first pole ear 310 and a second pole ear 320. Along the length direction of the electrode assembly 300, the first pole ear 310 and the second pole ear 320 are respectively connected to the two surfaces of the winding core 330 arranged in opposite directions.

[0072] It should be noted that, in this embodiment, the first pole tab 310 is a negative pole tab, and the second pole tab 320 is a positive pole tab. In other embodiments, the first pole tab 310 may be a positive pole tab, and the second pole tab 320 may be a negative pole tab.

[0073] For the convenience of description, we define Figure 2The length direction of the end cap assembly 100 is the X-axis direction, the width direction of the end cap assembly 100 is the Y-axis direction, and the thickness direction of the end cap assembly 100 is the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. The directional terms such as "upper" and "lower" mentioned in the description of the embodiment of the present application are based on the attached specification. Figure 2 The description of the orientation shown in the figure is that the positive direction of the Z axis is "up" and the negative direction of the Z axis is "down", which does not constitute a limitation on the actual application scenario of the energy storage device 1000. A certain tolerance is allowed for the terms "same", "equal" or "parallel" used in the following text.

[0074] Please refer to Figure 3 , Figure 5 and Figure 6 , Figure 5 for Figure 3 A schematic diagram of an exploded structure of an end cover assembly of the energy storage device shown in one angle; Figure 6 for Figure 5 A schematic diagram of the exploded structure of the end cover assembly shown in another angle.

[0075] The end cap assembly 100 includes an end cap 60 and a lower plastic 30, and the lower plastic 30 is mounted on the end cap 60. The end cap 60 in this embodiment is a bare aluminum part, and the lower plastic 30 is made of plastic material and is insulated. The end cap assembly 100 also includes an explosion-proof valve 40. The explosion-proof valve 40 is mounted on the end cap 60. The end cap assembly 100 also includes a first pole 51 and a second pole 52. The first pole 51 is inserted through the lower plastic 30 and the end cap 60. The second pole 52 is inserted through the lower plastic 30 and the end cap 60. In this embodiment, the first pole 51 is a negative pole. The second pole 52 is a positive pole.

[0076] It should be noted that, in other embodiments, the first pole 51 may be a positive pole, and the second pole 52 may be a negative pole.

[0077] The lower plastic 30 includes a first lower plastic 10 and a second lower plastic 20. Along the length direction of the lower plastic 30, the length of the first lower plastic 10 is less than the length of the second lower plastic 20. In this embodiment, the first lower plastic 10 and the second lower plastic 20 are split structures. In other embodiments, the first lower plastic 10 and the second lower plastic 20 can also be an integrally formed structure.

[0078] Please refer to Figure 7 and Figure 8 , Figure 7 for Figure 5 A schematic diagram of the structure of the first lower plastic at one angle is shown; Figure 8 for Figure 7 A schematic structural diagram of the first lower plastic from another angle is shown.

[0079] The first lower plastic 10 is a long thin plate. The first lower plastic 10 includes a first lower plastic body 11. The first lower plastic body 11 includes a first top surface 111, a first bottom surface 112 and a first side surface 118. Along the thickness direction of the first lower plastic 10, the first top surface 111 and the first bottom surface 112 are arranged back to back. Along the length direction of the first lower plastic 10, the first side surface 118 is located at one end of the first lower plastic 10. The first side surface 118 is connected between the first top surface 111 and the first bottom surface 112. The first lower plastic body 11 is provided with a first pole through hole 113. Along the thickness direction of the first lower plastic 10, the first pole through hole 113 penetrates the first top surface 111 and the first bottom surface 112. Along the length direction of the first lower plastic 10, the first pole through hole 113 is located at the end of the first lower plastic body 11. Specifically, the first pole through hole 113 is located at one end of the first lower plastic 10 close to the first side surface 118.

[0080] The first lower plastic 10 is provided with a first recessed groove 114. Along the thickness direction of the first lower plastic 10, the first recessed groove 114 is recessed from the first bottom surface 112 to the first top surface 111, and is convexly provided on the first top surface 111 to form a first limiting convex portion 12. Along the length direction of the first lower plastic 10, the first recessed groove 114 penetrates the end surface of the first lower plastic body 11 away from the first side surface 118. The first recessed groove 114 is spaced apart from the first pole through hole 113. It can be understood that the first lower plastic 10 includes a first limiting convex portion 12. Along the thickness direction of the first lower plastic 10, the first limiting convex portion 12 is convexly provided on the first top surface 111 of the first lower plastic body 11. The orthographic projection of the first limiting convex portion 12 on the first bottom surface 112 completely covers the first recessed groove 114. The first limiting convex portion 12 includes a first concave surface 121. Along the thickness direction of the first lower plastic 10 , the first concave surface 121 and the surface of the bottom wall of the first sink groove 114 are arranged in opposite directions.

[0081] Please continue reading Figure 7 and Figure 8 The first lower plastic 10 is provided with a first groove 14 and a third groove 15. The first groove 14 and the third groove 15 are both located at the first limiting protrusion 12. Along the length direction of the first lower plastic 10, the first groove 14 is located at the end of the first lower plastic 10 away from the first side surface 118. The third groove 15 is located at a side of the first groove 14 close to the first pole through hole 113.

[0082] The first groove 14 includes a first sub-groove 141 and a second sub-groove 142. Along the thickness direction of the first lower plastic 10, the first sub-groove 141 is recessed from the first recessed surface 121 to the surface of the bottom wall of the first sink 114, and a first sub-protrusion 161 is convexly formed on the surface of the bottom wall of the first sink 114. The first sub-protrusion 161 includes a first surface 1611. Along the thickness direction of the first lower plastic 10, the first surface 1611 is disposed opposite to the first top surface 111. Along the thickness direction of the first lower plastic 10, the second sub-groove 142 is recessed from the surface of the bottom wall of the first sub-groove 141 to the first surface 1611, and a second sub-protrusion 162 is convexly formed on the first surface 1611 to form the second sub-protrusion 162. The second sub-groove 142 is connected to the first sub-groove 141. It can be understood that the second sub-protrusion 162 is convexly disposed on the surface of the first sub-protrusion 161 opposite to the first top surface 111. Along the thickness direction of the first lower plastic 10, the orthographic projection of the second sub-protrusion 162 on the first top surface 111 is located within the orthographic projection of the first sub-protrusion 161. The first sub-protrusion 161 and the second sub-protrusion 162 together form the first protrusion 16. Along the width direction of the first lower plastic 10, the first protrusion 16 is spaced from the two side walls of the first sink 114. The ratio of the width d1 of the first protrusion 16 to the width w of the first sink 114 is in the range of: 0.7≤d1 / w≤0.9.

[0083] It should be noted that the width of the first protrusion 16 refers to the distance between two points of the first protrusion 16 that are farthest apart in the width direction of the first lower plastic 10 .

[0084] In this embodiment, the first sub-protrusion 161 and the second sub-protrusion 162 are both rectangular protrusions. The longitudinal axis of the first sub-protrusion 161 is parallel to the X axis. The width of the first protrusion 161 is the width of the first sub-protrusion 161.

[0085] In other embodiments, the first sub-protrusion 161 may also be a circle, an ellipse or other regular or irregular shapes.

[0086] In this embodiment, the thickness of the first sub-protrusion 161 is equal to the depth of the first recessed groove 114. In other embodiments, the thickness of the first sub-protrusion 161 and the depth of the first recessed groove 114 may also be different.

[0087] Along the thickness direction of the first lower plastic 10, the third groove 15 is recessed from the first recessed surface 121 to the surface of the bottom wall of the first sink 114, and a third protrusion 17 is convexly formed on the surface of the bottom wall of the first sink 114. Along the width direction of the first lower plastic 10, the third protrusion 17 is spaced from the two side walls of the first sink 114. The volume of the third protrusion 17 is smaller than the volume of the first protrusion 16. The ratio of the width d3 of the third protrusion 17 to the width w of the first sink 114 is in the range of: 0.7≤d3 / w≤0.9.

[0088] It should be noted that the width of the third protrusion 17 refers to the distance between two points of the third protrusion 17 that are farthest from each other in the width direction of the first lower plastic 10 .

[0089] In this embodiment, the third protrusion 17 is a rectangular protrusion. The axis of the third protrusion 17 in the longitudinal direction is parallel to the X-axis. In other embodiments, the third protrusion 17 may also be a circle, an ellipse or other regular or irregular shapes.

[0090] In this embodiment, the thickness of the third protrusion 17 is equal to the thickness of the first sub-protrusion 161 , and the width of the third protrusion 17 is equal to the width of the second sub-protrusion 162 .

[0091] In other embodiments, the thickness of the third protrusion 17 may not be equal to the thickness of the first sub-protrusion 161. The width of the third protrusion 17 may not be equal to the width of the second sub-protrusion 162.

[0092] In this embodiment, along the length direction of the first lower plastic 10 , the distance between the first protrusion 16 and the third protrusion 17 is less than or equal to 25 mm.

[0093] It should be noted that the distance between the first protrusion 16 and the third protrusion 17 refers to the distance between the two closest points of the first protrusion 16 and the third protrusion 17 along the length direction of the first lower plastic 10 .

[0094] In other embodiments, the first lower plastic 10 may not be provided with the first groove 14 and the third groove 15 , and the first protrusion 16 and the third protrusion 17 are directly protruded from the surface of the bottom wall of the first sink 114 .

[0095] It is understandable that by forming the first protrusion 16 and the third protrusion 17 while forming the first protrusion 16 and the third protrusion 17, the weight of the first lower plastic 10 can be reduced and the structural strength of the first lower plastic body 11 can be enhanced.

[0096] The first lower plastic 10 further includes a first convex rib 18 and a second convex rib 19. The first convex rib 18 and the second convex rib 19 are both convexly disposed on the first bottom surface 112. The first convex rib 18 and the second convex rib 19 both extend along the length direction of the first lower plastic 10, and the lengths of the first convex rib 18 and the second convex rib 19 are both equal to the length of the first lower plastic body 11. Along the width direction of the first lower plastic 10, the first convex rib 18 and the second convex rib 19 are respectively connected to opposite sides of the first lower plastic body 11. Along the thickness direction of the first lower plastic 10, the thicknesses of the first convex rib 18 and the second convex rib 19 both protrude from the first protrusion 16, or are both flush with the first protrusion 16.

[0097] Please refer to Fig. 9 and Fig.10 , Fig. 9 for Figure 5 A schematic diagram of the structure of the second lower plastic at one angle is shown; Fig.10 for Fig. 9 A schematic structural diagram of the second lower plastic from another angle is shown.

[0098] The second lower plastic 20 includes a second lower plastic body 21. The second lower plastic body 21 includes a second top surface 211, a second bottom surface 212, and a second side surface 218. Along the thickness direction of the second lower plastic 20, the second top surface 211 and the second bottom surface 212 are arranged opposite to each other. Along the length direction of the second lower plastic 20, the second side surface 218 is located at one end of the second lower plastic 20. The second side surface 218 is connected between the second top surface 211 and the second bottom surface 212. The second lower plastic body 21 is provided with a second pole through hole 213. Along the thickness direction of the second lower plastic 20, the second pole through hole 213 penetrates the second top surface 211 and the second bottom surface 212. Along the length direction of the second lower plastic 20, the second pole through hole 213 is located at the end of the second lower plastic body 21. Specifically, the second pole through hole 213 is located at one end of the second lower plastic 20 close to the second side surface 218.

[0099] The second lower plastic 20 is provided with a second sink 214. Along the thickness direction of the second lower plastic 20, the second sink 214 is recessed from the second bottom surface 212 to the second top surface 211, and is convexly provided on the second top surface 211 to form a second limiting convex portion 22. Along the length direction of the second lower plastic 20, the second sink 214 penetrates the end surface of the second lower plastic body 21 away from the second pole through hole 213. The depth of the second sink 214 is equal to the depth of the first sink 114. The width of the second sink 214 is equal to the width of the first sink 114. The width of the second sink 214 and the width of the first sink 114 are both w. The second sink 214 is spaced apart from the second pole through hole 213. It can be understood that the second lower plastic 20 includes a second limiting convex portion 22. Along the thickness direction of the second lower plastic 20, the second limiting convex portion 22 is convexly provided on the second top surface 211 of the second lower plastic body 21. The orthographic projection of the second limiting protrusion 22 on the second bottom surface 212 completely covers the second sink groove 214. The second limiting protrusion 22 includes a second concave surface 221. Along the thickness direction of the second lower plastic 20, the second concave surface 221 and the surface of the bottom wall of the second sink groove 214 are arranged in opposite directions.

[0100] The second lower plastic 20 is provided with a vent hole 216. The vent hole 216 is located at the second position-limiting protrusion 22. Along the thickness direction of the second lower plastic 20, the vent hole 216 penetrates the second concave surface 221 of the second position-limiting protrusion 22 and the surface of the bottom wall of the second sink 214. Along the length direction of the second lower plastic 20, the vent hole 216 is located at one end of the second lower plastic 20 away from the second side surface 218.

[0101] The second lower plastic 20 further includes an explosion-proof fence 23. The explosion-proof fence 23 is provided with a plurality of air holes 231. Along the thickness direction of the explosion-proof fence 23, the plurality of air holes 231 all penetrate the two surfaces of the explosion-proof fence 23 that are arranged opposite to each other. The explosion-proof fence 23 is installed on the hole wall of the air hole 216.

[0102] The second lower plastic 20 is provided with a second groove 24 and a fourth groove 25. The second groove 24 and the fourth groove 25 are both located at the second limiting protrusion 22. Along the length direction of the second lower plastic 20, the second groove 24 is located between the vent 216 and the second pole through hole 213, and is arranged adjacent to the vent 216. The fourth groove 25 is located between the second groove 24 and the second pole through hole 213.

[0103] The second groove 24 includes a third sub-groove 241 and a fourth sub-groove 242. Along the thickness direction of the second lower plastic 20, the third sub-groove 241 is recessed from the second recessed surface 221 to the surface of the bottom wall of the second sink 214, and a third sub-protrusion 261 is convexly formed on the surface of the bottom wall of the second sink 214. The third sub-protrusion 261 includes a second surface 2611. Along the thickness direction of the second lower plastic 20, the second surface 2611 is arranged opposite to the second top surface 211. Along the thickness direction of the second lower plastic 20, the fourth sub-groove 242 is recessed from the surface of the bottom wall of the third sub-groove 241 to the second surface 2611, and a fourth sub-protrusion 262 is convexly formed on the second surface 2611 to form the fourth sub-protrusion 262. The fourth sub-groove 242 is connected to the third sub-groove 241. It can be understood that the fourth sub-protrusion 262 is convexly provided on the surface of the third sub-protrusion 261 opposite to the second top surface 211. Along the thickness direction of the second lower plastic 20, the orthographic projection of the fourth sub-protrusion 262 on the second top surface 211 is located within the orthographic projection of the third sub-protrusion 261. The third sub-protrusion 261 and the fourth sub-protrusion 262 together form the second protrusion 26. Along the width direction of the second lower plastic 20, the second protrusion 26 is spaced from the two side walls of the second groove 214. The ratio of the width d2 of the second protrusion 26 to the width w of the second groove 214 is in the range of: 0.6≤d2 / w≤0.8.

[0104] It should be noted that the width of the second protrusion 26 refers to the distance between two points of the second protrusion 26 that are farthest from each other in the width direction of the second lower plastic 20 .

[0105] In this embodiment, the shape of the second protrusion 26 is the same as that of the first protrusion 16. The volume of the second protrusion 26 is equal to that of the first protrusion 16. The height of the second protrusion 26 is equal to that of the first protrusion 16. The width of the second protrusion 26 is the width of the third sub-protrusion 261.

[0106] In other embodiments, the shape of the second protrusion 26 may be different from that of the first protrusion 16. The volume of the second protrusion 26 may also be different from that of the first protrusion 16. The third sub-protrusion 261 may also be a circle, an ellipse or other regular or irregular shapes.

[0107] Along the thickness direction of the second lower plastic 20, the fourth groove 25 is recessed from the second recessed surface 221 to the surface of the bottom wall of the second sink 214, and is convexly formed on the surface of the bottom wall of the second sink 214 to form a fourth protrusion 27. Along the width direction of the second lower plastic 20, the fourth protrusion 27 is spaced from the two side walls of the second sink 214. The volume of the fourth protrusion 27 is smaller than the volume of the second protrusion 26. The ratio of the width d4 of the fourth protrusion 27 to the width w of the second sink 214 is in the range of: 0.7≤d4 / w≤0.9.

[0108] It should be noted that the width of the fourth protrusion 27 refers to the distance between two points of the fourth protrusion 27 that are farthest from each other in the width direction of the second lower plastic 20 .

[0109] In this embodiment, the shape of the fourth protrusion 27 is the same as that of the third protrusion 17. The volume of the fourth protrusion 27 is equal to that of the third protrusion 17.

[0110] In other embodiments, the shape of the fourth protrusion 27 may be different from that of the third protrusion 17. The volume of the fourth protrusion 27 may also be different from that of the third protrusion 17. The fourth protrusion 27 may also be in other regular or irregular shapes such as a circle or an ellipse.

[0111] In this embodiment, the second lower plastic 20 further includes a fifth groove 201. The fifth groove 201 is located between the second groove 24 and the fourth groove 25. Along the thickness direction of the second lower plastic 20, the fifth groove 201 is recessed from the second recessed surface 221 to the surface of the bottom wall of the second sink 214, and is convexly formed on the surface of the bottom wall of the second sink 214 to form a fifth protrusion 202. In this embodiment, the thickness of the fifth protrusion 202 is equal to the thickness of the fourth protrusion 27. The width of the fifth protrusion 202 is equal to the width of the fourth protrusion 27. The ratio of the width d5 ​​of the fifth protrusion 202 to the width w of the second sink 214 is in the range of: 0.7≤d5 / w≤0.9.

[0112] It should be noted that, in other embodiments, the thickness of the fifth protrusion 202 may not be equal to the thickness of the fourth protrusion 27. The width of the fifth protrusion 202 may not be equal to the width of the fourth protrusion 27. The second lower plastic 20 may not be provided with the second groove 24, the fourth groove 25 and the fifth groove 201, and the second protrusion 26, the fourth protrusion 27 and the fifth protrusion 202 may be directly protruded on the surface of the bottom wall of the second sink 214.

[0113] It can be understood that by forming the second protrusion 26, the fourth protrusion 27 and the fifth protrusion 202 at the same time, forming the second groove 24 corresponding to the second protrusion 26, the fourth groove 25 corresponding to the fourth protrusion 27, and the fifth groove 201 corresponding to the fifth protrusion 202, the weight of the second lower plastic 20 can be reduced and the structural strength of the second lower plastic body 21 can be enhanced.

[0114] The second lower plastic body 21 is further provided with a liquid injection hole 217. The liquid injection hole 217 is located on the second position-limiting protrusion 22. Along the thickness direction of the second lower plastic 20, the liquid injection hole 217 penetrates the second concave surface 221 of the second position-limiting protrusion 22 and the surface of the bottom wall of the second sink 214. Along the length direction of the second lower plastic 20, the liquid injection hole 217 is located between the fourth protrusion 27 and the fifth protrusion 202.

[0115] The second lower plastic 20 further includes a third convex rib 28 and a fourth convex rib 29. The third convex rib 28 and the fourth convex rib 29 are both convexly disposed on the second bottom surface 212. The third convex rib 28 and the fourth convex rib 29 extend along the length direction of the second lower plastic 20, and the lengths of the third convex rib 28 and the fourth convex rib 29 are equal to the length of the second lower plastic body 21. Along the width direction of the second lower plastic 20, the third convex rib 28 and the fourth convex rib 29 are respectively connected to opposite sides of the second lower plastic body 21. Along the thickness direction of the second lower plastic 20, the third convex rib 28 and the fourth convex rib 29 are both protruding from the second protrusion 26, or are flush with the second protrusion 26.

[0116] Please continue reading Figure 4 and Figure 5 The end cover 60 is a long thin plate. The end cover 60 includes a first mounting surface 611, a second mounting surface 612, a first end surface 618, and a second end surface 619. Along the thickness direction of the end cover 60, the first mounting surface 611 and the second mounting surface 612 are arranged in opposite directions. Along the length direction of the end cover 60, the first end surface 618 and the second end surface 619 are located at opposite ends of the end cover 60, and the first end surface 618 and the second end surface 619 are arranged in opposite directions.

[0117] The end cover 60 is provided with a first through hole 613 and a second through hole 614. Along the thickness direction of the end cover 60, the first through hole 613 penetrates the first mounting surface 611 and the second mounting surface 612; the second through hole 614 penetrates the first mounting surface 611 and the second mounting surface 612. Along the length direction of the end cover 60, the first through hole 613 and the second through hole 614 are respectively located at opposite ends of the end cover 60. Specifically, the first through hole 613 is located on a side of the end cover 60 close to the first end surface 618. The second through hole 614 is located on a side of the end cover 60 close to the second end surface 619. The first through hole 613 is used for the first pole 51 to pass through. The second through hole 614 is used for the second pole 52 to pass through.

[0118] The end cover 60 is provided with a mounting groove 615. The mounting groove 615 is a long strip-shaped groove. Along the length direction of the end cover 60, the mounting groove 615 is located between the first through hole 613 and the second through hole 614. The mounting groove 615 is formed by the second mounting surface 612 being recessed in the direction of the first mounting surface 611, and a convex hump 62 is formed on the first mounting surface 611. It can be understood that along the thickness direction of the end cover 60, the convex hump 62 is convexly arranged on the first mounting surface 611. The orthographic projection of the convex hump 62 on the second mounting surface 612 completely covers the mounting groove 615. The convex hump 62 includes a stamping surface 621. Along the thickness direction of the end cover 60, the stamping surface 621 and the surface of the bottom wall of the mounting groove 615 are arranged in a back-to-back manner.

[0119] The end cover 60 is provided with an explosion-proof hole 616. The explosion-proof hole 616 is located in the convex bulge 62. Along the thickness direction of the end cover 60, the explosion-proof hole 616 penetrates the stamping surface 621 of the convex bulge 62 and the surface of the bottom wall of the groove of the mounting groove 615. Along the length direction of the end cover 60, the distance between the hole axis of the explosion-proof hole 616 and the first end face 618 is less than the distance between the hole axis of the explosion-proof hole 616 and the second end face 619. Specifically, the ratio of the distance between the hole axis of the explosion-proof hole 616 and the first end face 618 to the distance between the explosion-proof hole 616 and the second end face 619 is in the range of. The explosion-proof valve 40 is mounted on the hole wall of the explosion-proof hole 616. In this embodiment, the end cover 60 is further provided with a first recess 641, a second recess 651, a fourth recess 661 and a fifth recess 671. The first recess 641, the second recess 651, the fourth recess 661 and the fifth recess 671 are all located in the convex bulge 62. Along the length direction of the end cover 60, the first recess 641, the second recess 651, the fourth recess 661 and the fifth recess 671 are arranged at intervals from each other. The first recess 641 is located between the explosion-proof hole 616 and the first through hole 613. The second recess 651 is located between the explosion-proof hole 616 and the second through hole 614. The first recess 641 and the second recess 651 are both arranged adjacent to the explosion-proof hole 616. The fourth recess 661 is located between the second recess 651 and the second through hole 614. The fifth recess 671 is located between the second recess 651 and the fourth recess 661.

[0120] Along the thickness direction of the end cover 60, the first concave portion 641 is concavely provided from the stamping surface 621 to the surface of the bottom wall of the mounting groove 615, and a first convex portion 642 is convexly provided on the surface of the bottom wall of the mounting groove 615. The shape of the first convex portion 642 matches the shape of the first groove 14. The first concave portion 641 is formed by stamping the end cover 60 twice.

[0121] Along the thickness direction of the end cover 60, the second recess 651 is recessed from the stamping surface 621 toward the surface of the bottom wall of the mounting groove 615, and a second convex portion 652 is convexly formed on the surface of the bottom wall of the mounting groove 615. The shape of the second convex portion 652 matches the shape of the second groove 24. The second recess 651 is formed by stamping the end cover 60 twice.

[0122] Along the thickness direction of the end cover 60, the fourth recess 661 is recessed from the stamping surface 621 to the surface of the bottom wall of the mounting groove 615, and a fourth protrusion 662 is protruded on the surface of the bottom wall of the mounting groove 615. The shape of the fourth protrusion 662 matches the shape of the fourth groove 25.

[0123] Along the thickness direction of the end cover 60, the fifth recess 671 is recessed from the stamping surface 621 to the surface of the bottom wall of the mounting groove 615, and a fifth protrusion 672 is convexly formed on the surface of the bottom wall of the mounting groove 615. The shape of the fifth protrusion 672 matches the shape of the fifth groove 201.

[0124] It should be noted that in other embodiments, the first recess 641 , the second recess 651 , the fourth recess 661 and the fifth recess 671 may not be present, and the first protrusion 642 , the second protrusion 652 , the fourth protrusion 662 and the fifth protrusion 672 may be directly protruded from the surface of the bottom wall of the mounting groove 615 .

[0125] It can be understood that by forming the first concave portion 641, the second concave portion 651, the fourth concave portion 661 and the fifth concave portion 671 while forming the first convex portion 642, the second convex portion 652, the fourth convex portion 662 and the fifth convex portion 672, the weight of the end cover 60 can be reduced and the structural strength of the end cover 60 can be enhanced. The end cover 60 is a plain aluminum sheet, and the first concave portion 641 and the second concave portion 651 are formed by stamping the end cover 60 twice, which can prevent the end cover 60 from being stretched too much by stamping, thereby preventing the end cover 60 from being broken.

[0126] The end cap 60 is further provided with a liquid injection hole 617. The liquid injection hole 617 is located in the convex bulge 62. Along the thickness direction of the end cap 60, the liquid injection hole 617 penetrates the stamping surface 621 of the convex bulge 62 and the surface of the bottom wall of the groove 615. Along the length direction of the end cap 60, the liquid injection hole 617 is located between the fourth concave portion 661 and the fifth concave portion 671.

[0127] Please continue reading Figure 4 and Figure 5 The first pole 51 includes a first flange 511 and a first column 512. The first column 512 is protruded from the surface of the first flange 511 in the thickness direction.

[0128] The second pole 52 includes a second flange 521 and a second column 522. The second column 522 is protruded from the surface of the second flange 521 in the thickness direction.

[0129] Please refer to Figure 5 , Figure 6 as well as Fig.11a , Fig.11b and Fig.11c , Fig.11a for Figure 5A cross-sectional schematic diagram of the assembly structure of the end cover, the first lower plastic, and the second lower plastic; Fig.11b for Fig.11a An enlarged schematic diagram of part A of the assembly structure of the end cover, the first lower plastic, and the second lower plastic; Fig.11c for Fig.11a The enlarged schematic diagram of part B of the assembly structure of the end cover and the first lower plastic and the second lower plastic is shown.

[0130] The first lower plastic 10 is stacked on one side of the end cover 60 where the first through hole 613 is provided. The first top surface 111 of the first lower plastic 10 is opposite to and fits with the second mounting surface 612 of the end cover 60. The first limiting protrusion 12 is limited in the mounting groove 615. The first protrusion 642 is limited in the first groove 14. The first protrusion 642 and the first groove 14 can achieve mutual positioning. Along the thickness direction of the end cover assembly 100, the first pole through hole 113 of the first lower plastic 10 is coaxially arranged with the first through hole 613 of the end cover 60 and is connected to each other.

[0131] The second lower plastic 20 is stacked on one side of the end cap 60 where the second through hole 614 is provided. The second top surface 211 of the second lower plastic 20 is opposite to and fits with the second mounting surface 612 of the end cap 60. The second limiting protrusion 22 is limited in the mounting groove 615. The second protrusion 652 is limited in the second groove 24. The second protrusion 652 and the second groove 24 can achieve mutual positioning. The fourth protrusion 662 is limited in the fourth groove 25. The fourth protrusion 662 and the fourth groove 25 can achieve mutual positioning. The fifth protrusion 672 is inserted into the fifth groove 201. The fifth protrusion 672 and the fifth groove 201 can achieve mutual positioning. Along the thickness direction of the end cap assembly 100, the second pole through hole 213 of the second lower plastic 20 is coaxially arranged with the second through hole 614 of the end cap 60 and is connected to each other. The injection through hole 217 of the second lower plastic 20 is opposite to and connected with the injection hole 617 of the end cap 60. The vent hole 216 of the second lower plastic 20 is opposite to and communicates with the explosion-proof hole 616 of the end cover 60 .

[0132] The length direction of the second lower plastic 20 and the length direction of the first lower plastic 10 are the same as the length direction of the end cap 60. The second lower plastic 20 and the first lower plastic 10 are arranged side by side along the length direction of the end cap assembly 100. The end of the second lower plastic body 21 away from the second side surface 218 is opposite to the end of the first lower plastic body 11 away from the first side surface 118. The second lower plastic body 21 and the first lower plastic body 11 together form the lower plastic body 31 of the lower plastic 30. The second top surface 211 of the second lower plastic body 21 and the first top surface 111 of the first lower plastic body 11 are connected to each other to form the first surface 311 of the lower plastic body 31. The second bottom surface 212 of the second lower plastic body 21 and the first bottom surface 112 of the first lower plastic body 11 are connected to each other to form the second surface 312 of the lower plastic 30. Along the length direction of the lower plastic 30, the first side surface 118 of the first lower plastic 10 and the second side surface 218 of the second lower plastic 20 are respectively located at opposite ends of the lower plastic 30. The first side surface 118 and the second side surface 218 are arranged to face away from each other.

[0133] The third rib 28 of the second lower plastic 20 is opposite to the first rib 18 of the first lower plastic 10, and together they form a rib 33 of the lower plastic 30. The fourth rib 29 of the second lower plastic 20 is opposite to the second rib 19 of the first lower plastic 10, and together they form another rib 33 of the lower plastic 30. The second sink 214 of the second lower plastic 20 is opposite to the first sink 114 of the first lower plastic 10, and they are connected to each other. The second sink 214 of the second lower plastic 20 and the first sink 114 of the first lower plastic 10 together form a sink 314 of the lower plastic 30. The width of the sink 314 is equal to the width of the first sink 114 and the second sink 214. The width of the sink 314 is w. The depth of the sink 314 is equal to the depth of the first sink 114 and the second sink 214. The second limiting protrusion 22 of the second lower plastic 20 and the first limiting protrusion 12 of the first lower plastic 10 jointly form the limiting protrusion 32 of the lower plastic 30. The second concave surface 221 of the second limiting protrusion 22 and the first concave surface 121 of the first limiting protrusion 12 jointly form the concave surface 321 of the limiting protrusion 32. Along the thickness direction of the lower plastic 30, the surface of the bottom wall of the first sink 114 is flush with the surface of the bottom wall of the second sink 214, and jointly form the surface of the bottom wall of the sink 314. Along the length direction of the lower plastic 30, the distance between the hole axis of the vent 216 and the first side 118 is less than the distance between the hole axis of the vent 216 and the second side 218. The distance between the first protrusion 16 and the hole axis of the vent 216 is less than or equal to 25 mm. The distance between the second protrusion 26 and the hole axis of the vent 216 is less than or equal to 30 mm. Along the thickness direction of the end cover assembly 100 , the first protrusion 16 and the second protrusion 26 both protrude from the recessed groove 314 .

[0134] It should be noted that the distance between the first protrusion 16 and the hole axis of the vent hole 216 refers to the distance between the point of the first protrusion 16 closest to the vent hole 216 and the hole axis of the vent hole 216 along the length direction of the lower plastic 30. The distance between the second protrusion 26 and the hole axis of the vent hole 216 refers to the distance between the point of the second protrusion 26 closest to the vent hole 216 and the hole axis of the vent hole 216 along the length direction of the lower plastic 30.

[0135] Please refer to Figure 3 , Figure 4 , Fig.11b and Fig.11c , Fig.12a , Figure 12b and Fig.12c , Fig.12a for Figure 2 Schematic diagram of the cross-sectional structure of the energy storage device shown. Figure 12b for Fig.12a An enlarged schematic diagram of part C of the energy storage device shown; Fig.12c for Fig.12a An enlarged schematic diagram of part D of the energy storage device shown.

[0136] The electrode assembly 300 is accommodated in the accommodating cavity of the shell 400. Along the length direction of the energy storage device 1000, the first pole ear 310 and the second pole ear 320 of the electrode assembly 300 are respectively facing the two opposite side walls of the accommodating cavity. Along the width direction of the energy storage device 1000, the first wetted surface 3301 and the second wetted surface 3302 of the electrode assembly 300 are respectively facing the two opposite side walls of the accommodating cavity. One end of the first adapter sheet 210 is located between the first pole ear 310 and the side wall of the accommodating cavity and is electrically connected to the first pole ear 310. The other end of the first adapter sheet 210 is bent and located on the side of the opening of the winding core 330 facing the shell 400. One end of the second adapter sheet 220 is located between the second pole ear 320 and the side wall of the accommodating cavity and is electrically connected to the second pole ear 320. The other end of the second adapter sheet 220 is bent and located on the side of the opening of the winding core 330 facing the shell 400. Along the length direction of the energy storage device 1000, one end of the first adapter plate 210 connected to the first pole ear 310 is spaced apart from the side wall of the accommodating cavity. One end of the second adapter plate 220 connected to the second pole ear 320 is spaced apart from the side wall of the accommodating cavity. It can be understood that along the length direction of the energy storage device 1000, a large space needs to be reserved between the opposite sides of the electrode assembly 300 and the cavity wall of the accommodating cavity to accommodate the first adapter plate 210 and the second adapter plate 220.

[0137] The end cap assembly 100 is mounted on one end of the electrode assembly 300 and is sealed at the opening. Specifically, the periphery of the end cap 60 is connected to the edge of the opening of the shell 400. The lower plastic 30 is located in the accommodating cavity of the shell 400. Along the height direction of the energy storage device 1000, the lower plastic 30 is located between the end cap 60 and the electrode assembly 300. The sink 314 of the lower plastic 30 faces the electrode assembly 300. The first protrusion 16 and the second protrusion 26 of the lower plastic 30 are both in contact with the electrode assembly 300. It can be understood that the first protrusion 16 and the second protrusion 26 can prevent the electrode assembly 300 from moving in the height direction of the energy storage device 1000.

[0138] The third protrusion 17, the fourth protrusion 27 and the fifth protrusion 202 of the lower plastic 30 are spaced apart from the electrode assembly 300. Along the width direction of the energy storage device 1000, the two ribs 33 of the lower plastic 30 are respectively located on opposite sides of the electrode assembly 300, and the two ribs 33 are spaced apart from the electrode assembly 300.

[0139] The first flange 511 of the first pole 51 is crimped to the first top surface 111 of the first lower plastic 10. The first column 512 of the first pole 51 is inserted through the first through hole 613 of the end cover 60 and the first pole through hole 113 of the first lower plastic 10. The first column 512 is electrically connected to the first adapter 210. The second flange 521 of the second pole 52 is crimped to the second top surface 211 of the second lower plastic 20. The second column 522 of the second pole 52 is inserted through the second through hole 614 of the end cover 60 and the second pole through hole 213 of the second lower plastic 20. The second flange 521 is electrically connected to the second adapter 220. It can be understood that along the height direction of the energy storage device 1000, one end of the first adapter 210 is connected to the first pole ear 310, and the other end of the first adapter 210 is bent and located between the lower plastic 30 and the electrode assembly 300. One end of the second adapter plate 220 is connected to the second electrode tab 320 , and the other end of the second adapter plate 220 is bent and located between the lower plastic 30 and the electrode assembly 300 .

[0140] It can be understood that in the present application, along the length direction of the end cap assembly 100, the distance between the hole axis of the explosion-proof hole 616 and the first end face 618 of the end cap 60 is less than the distance between the hole axis of the explosion-proof hole 616 and the second end face 619 of the end cap 60. The distance between the hole axis of the vent 216 and the first side 118 of the lower plastic 30 is less than the distance between the hole axis of the vent 216 and the second side 218 of the lower plastic 30. The explosion-proof hole 616 and the vent 216 are opposite and connected. That is to say, the vent 216 and the explosion-proof hole 616 are not located in the middle of the energy storage device 1000, and the vent 216 and the explosion-proof hole 616 are offset. When the energy storage device 1000 is thermally runaway, the gas generated in the electrode assembly 300 diffuses to the surroundings, and finally discharges the energy storage device 1000 through the vent 216 and the explosion-proof hole 616 in sequence. The gas flow generated between the first side surface 118 and the vent hole 216 is smaller than the gas flow generated between the second side surface 218 and the vent hole 216. Therefore, along the length direction of the end cap assembly 100, the gas flow flowing to the vent hole 216 on both sides of the vent hole 216 is not balanced. Compared with the prior art that sets the vent hole 216 in the middle of the lower plastic 30, the gas flow flowing to the vent hole 216 on both sides of the vent hole 216 is balanced. In the present application, the turbulent kinetic energy and turbulent dissipation generated by the gas on both sides of the vent hole 216 at the vent hole 216 are relatively small, which can reduce the mutual impact of the gas on both sides of the vent hole 216, reduce the pressure loss of the gas at the vent hole 216, and thus speed up the gas passing through the vent hole 216 of the lower plastic 30 and then passing through the explosion-proof hole 616 of the end cap 60 to discharge the energy storage device 1000. That is to say, in the present application, by offsetting the vent hole 216 and the explosion-proof hole 616 , the exhaust speed of the energy storage device 1000 can be increased, thereby improving the safety performance of the energy storage device 1000 .

[0141] By providing the sink 314 in the lower plastic 30, the space between the electrode assembly 300 and the lower plastic 30 can be increased, that is, the flow space of the gas between the electrode assembly 300 and the lower plastic 30 is increased, so that the gas flow between the electrode assembly 300 and the lower plastic 30 can be smoother, the gas flow rate can be increased, and the speed of gas discharge from the energy storage device 1000 can be accelerated. The lower plastic 30 is provided with two convex ribs 33, and along the width direction of the energy storage device 1000, the two convex ribs 33 are spaced from the electrode assembly 300, and the two convex ribs 33 and the lower plastic body 31 and the electrode assembly 300 form a gas flow channel. The gas generated in the energy storage device 1000 can flow directly from the gas flow channel to the vent 216, and escape to the outside of the energy storage device 1000 through the vent 216 and the explosion-proof hole 616 in turn, thereby increasing the gas discharge speed.

[0142] Along the length direction of the end cap assembly 100, a first protrusion 16 is provided on the side of the vent hole 216 close to the first side surface 118. The first protrusion 16 is located between the vent hole 216 and the first side surface 118. The first protrusion 16 is spaced apart from the two groove side walls of the sink 314. When the gas reaches the first protrusion 16, the flow space of the gas is reduced. According to the shrinking effect, the flow rate of the gas increases after the gas enters the small space from the large space. Therefore, in the present application, when the gas reaches the first protrusion 16, the flow rate of the gas increases, and the gas can accelerate through the first protrusion 16 and continue to flow to the vent hole 216. Along the length direction of the end cap assembly 100, the distance between the first protrusion 16 and the hole axis of the vent hole 216 is less than or equal to 25 mm. After the gas accelerates through the first protrusion 16, it can still escape to the outside of the energy storage device 1000 through the vent hole 216 and the explosion-proof hole 616 at a relatively fast speed. Along the width direction of the end cover assembly 100, the first protrusion 16 is spaced apart from the two groove side walls of the groove 314, and the ratio range of the width of the first protrusion 16 to the width of the groove 314 is: 0.7≤d1 / w≤0.9, which ensures that the gas can be accelerated through the first protrusion 16 while ensuring the gas flux through the first protrusion 16.

[0143] Similarly, along the length direction of the lower plastic 30, a second protrusion 26 is provided on one side of the vent hole 216 close to the second side surface 218, and the second protrusion 26 is located between the vent hole 216 and the second side surface 218. The second protrusion 26 is spaced apart from the two groove side walls of the sink 314. Therefore, in the present application, when the gas reaches the second protrusion 26, the flow rate of the gas increases, and the gas can accelerate through the second protrusion 26 and continue to flow to the vent hole 216. Along the length direction of the end cap assembly 100, the distance between the second protrusion 26 and the hole axis of the vent hole 216 is less than or equal to 30 mm. After the gas accelerates through the second protrusion 26, it can still escape to the outside of the energy storage device 1000 through the vent hole 216 and the explosion-proof hole 616 at a relatively fast speed. Along the width direction of the end cover assembly 100, the second protrusion 26 is spaced apart from the two groove side walls of the groove 314, and the ratio range of the width of the second protrusion 26 to the width of the groove 314 is: 0.6≤d2 / w≤0.8, which ensures that the gas can be accelerated through the second protrusion 26 while ensuring the gas flux through the second protrusion 26.

[0144] In addition, along the length direction of the end cap assembly 100, a third protrusion 17 is arranged between the first protrusion 16 and the first pole through hole 113, and the third protrusion 17 is arranged to be spaced apart from the two groove side walls of the sink 314. According to the shrinking effect, the flow rate of the gas will also increase when the gas passes through the third protrusion 17. Therefore, when the gas passes through the third protrusion 17 and the first protrusion 16 in sequence, the gas will be accelerated twice in succession. Along the width direction of the end cap assembly 100, the third protrusion 17 is spaced apart from the two groove side walls of the sink 314, and the ratio of the width of the third protrusion 17 to the width of the sink 314 is in the range of: 0.7≤d3 / w≤0.9, which ensures that the gas can be accelerated through the third protrusion 17 while ensuring the gas flux through the third protrusion 17. Along the length direction of the end cap assembly 100, the distance between the third protrusion 17 and the first protrusion 16 is less than or equal to 25 mm, so that after the gas is accelerated for the first time through the third protrusion 17, the gas can reach the first protrusion 16 at a faster speed, and the speed of the gas is further accelerated. The volume of the third protrusion 17 is smaller than the volume of the first protrusion 16, and the gas flux through the third protrusion 17 is larger than the gas flux through the first protrusion 16, so the gas can pass through the third protrusion 17 and the first protrusion 16 in sequence.

[0145] Along the length direction of the end cap assembly 100, the fourth protrusion 27 is arranged between the second protrusion 26 and the second pole through hole 213, and the fourth protrusion 27 is arranged to be spaced apart from the two groove side walls of the sink 314. According to the shrinking effect, the flow rate of the gas will also increase when the gas passes through the fourth protrusion 27. Therefore, when the gas passes through the fourth protrusion 27 and the second protrusion 26 in sequence, the gas will be accelerated twice in succession. Along the width direction of the end cap assembly 100, the fourth protrusion 27 is spaced apart from the two groove side walls of the sink 314, and the ratio of the width of the fourth protrusion 27 to the width of the sink 314 is in the range of: 0.7≤d4 / w≤0.9, which ensures that the gas can be accelerated through the fourth protrusion 27 while ensuring the gas flux through the fourth protrusion 27.

[0146] In the present application, since the vent hole 216 is close to the first side surface 118, the gas flow passage space between the vent hole 216 and the first side surface 118 is smaller than the gas flow passage space between the vent hole 216 and the second side surface 218. The volume of the first protrusion 16 is equal to the volume of the second protrusion 26, and the volume of the third protrusion 17 is equal to the volume of the fourth protrusion 27. By additionally arranging the fifth protrusion 202 between the vent hole 216 and the second side surface 218, the gas flow passage space between the vent hole 216 and the first side surface 118 and the gas flow passage space between the vent hole 216 and the second side surface 218 can be made substantially equal. Therefore, it is possible to prevent the gas produced between the vent hole 216 and the first side surface 118 from drifting over the explosion-proof valve 40, resulting in a collision with the gas from the vent hole 216 and the second side surface 218, thereby reducing the exhaust efficiency.

[0147] In the present application, the vent hole 216 and the explosion-proof fence 23 are located at one end of the second lower plastic 20 away from the second side surface 218. When the energy storage device 1000 is in thermal runaway, the gas inside the energy storage device 1000 can impact the explosion-proof fence 23 to support the end of the second lower plastic 20 provided with the explosion-proof fence 23, thereby preventing the end of the second lower plastic 20 provided with the explosion-proof fence 23 from sinking and contacting the electrode assembly 300, thereby damaging the electrode assembly 300.

[0148] In addition, the injection hole 217 is located between the fourth protrusion 27 and the fifth protrusion 202. When the electrolyte flows to the electrode assembly 300 through the injection hole 217, a large amount of electrolyte will avoid the fourth protrusion 27 and the fifth protrusion 202, flow along the width direction of the end cover assembly 100, and flow from both sides of the width direction of the lower plastic 30 to the first wetting surface 3301 and the second wetting surface 3302 of the electrode assembly 300, that is, the large surface of the electrode assembly 300, thereby improving the wetting effect of the electrode assembly 300.

[0149] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. An energy storage device, characterized in that: The end cover assembly comprises an end cover, a lower plastic and an explosion-proof valve, the end cover is provided with an explosion-proof hole, and the explosion-proof hole penetrates the end cover along the thickness direction of the end cover assembly, the end cover comprises a first end face and a second end face arranged opposite to the first end face, along the length direction of the end cover assembly, the explosion-proof hole is located between the first end face and the second end face, the distance between the hole axis of the explosion-proof hole and the first end face is smaller than the distance between the hole axis of the explosion-proof hole and the second end face, and the explosion-proof valve is installed on the hole wall of the explosion-proof hole; The lower plastic comprises a lower plastic body, the lower plastic is provided with a vent hole, and along the thickness direction of the end cover assembly, the vent hole penetrates the lower plastic body, the lower plastic body comprises a first side surface and a second side surface arranged opposite to the first side surface, along the length direction of the end cover assembly, the vent hole is located between the first side surface and the second side surface, and the distance between the hole axis of the vent hole and the first side surface is smaller than the distance between the vent hole and the second side surface; The lower plastic body includes a first surface and a second surface disposed opposite to the first surface, the first surface and the second surface are connected between the first side surface and the second side surface, the lower plastic is further provided with a sink groove, the sink groove is recessed from the second surface to the first surface, along the length direction of the end cover assembly, the sink groove is located between the first side surface and the second side surface, the sink groove includes two groove side walls and a groove bottom wall connected between the two groove side walls, and along the thickness direction of the end cover assembly, the vent hole penetrates the groove bottom wall of the sink groove; The lower plastic also includes a first protrusion, which is protruding from the surface of the bottom wall of the sink. Along the length direction of the end cover assembly, the first protrusion is located between the vent hole and the first side surface. Along the width direction of the end cover assembly, the first protrusion is spaced from the two side walls of the sink. The lower plastic body is stacked on the end cover, and along the length direction of the end cover assembly, the first side surface and the first end surface are oriented in the same direction, the second side surface and the second end surface are oriented in the same direction, and the explosion-proof hole is opposite to and connected to the vent hole.

2. The energy storage device according to claim 1, characterized in that: The energy storage device further comprises a shell, an electrode assembly, a first adapter plate and a second adapter plate, the shell is provided with an opening and a receiving cavity, and along the height direction of the energy storage device, the opening is located at one end of the receiving cavity and is in communication with the receiving cavity; The electrode assembly comprises a winding core, a first pole lug and a second pole lug, and along the length direction of the energy storage device, the first pole lug and the second pole lug are respectively connected to two surfaces of the winding core that are arranged in opposite directions; The electrode assembly is accommodated in the accommodating cavity, the first pole ear and the second pole ear are both facing the side wall of the accommodating cavity, the end cover seals the opening, the lower plastic is accommodated in the accommodating cavity, and along the height direction of the energy storage device, the lower plastic is located between the electrode assembly and the end cover, one end of the first adapter sheet is located between the first pole ear and the side wall of the accommodating cavity and is electrically connected to the first pole ear, the other end of the first adapter sheet is bent and located between the lower plastic and the electrode assembly, one end of the second adapter sheet is located between the second pole ear and the side wall of the accommodating cavity and is electrically connected to the second pole ear, and the other end of the second adapter sheet is bent and located between the lower plastic and the electrode assembly.

3. The energy storage device according to claim 2, characterized in that: The ratio of the distance L2 between the hole axis of the explosion-proof hole and the second end surface to the distance L1 between the explosion-proof hole and the first end surface is in the range of 1<L2 / L1≤4.

4. The energy storage device according to claim 3, characterized in that: The lower plastic also includes a second protrusion, which is protruding from the surface of the bottom wall of the trough. Along the length direction of the end cover assembly, the second protrusion is located between the vent hole and the second side surface. Along the width direction of the lower plastic, the second protrusion is spaced apart from the two side walls of the trough.

5. The energy storage device according to claim 4, characterized in that: The ratio of the width d1 of the first protrusion to the width w of the recess is in the range of 0.7≤d1 / w≤0.9, and the ratio of the width d2 of the second protrusion to the width w of the recess is in the range of 0.6≤d2 / w≤0.

8.

6. The energy storage device according to claim 5, characterized in that: Along the length direction of the end cover assembly, the distance between the first protrusion and the hole axis of the vent hole is less than or equal to 25 mm, and the distance between the second protrusion and the hole axis of the vent hole is less than or equal to 30 mm.

7. The energy storage device according to claim 4, characterized in that: Along the thickness direction of the end cover assembly, the first protrusion and the second protrusion both protrude from the sink groove, and the height of the first protrusion is equal to the height of the second protrusion; Along the height direction of the energy storage device, the sink groove faces the electrode assembly, and the first protrusion and the second protrusion are both in contact with the winding core.

8. The energy storage device according to claim 7, characterized in that: The lower plastic also includes a third protrusion, which is protruding from the surface of the bottom wall of the sink, and along the thickness direction of the end cover assembly, the height of the third protrusion is less than the height of the first protrusion; Along the length direction of the end cover assembly, the third protrusion is located between the first protrusion and the first side surface, and the distance between the third protrusion and the first protrusion is less than or equal to 25 mm. Along the width direction of the lower plastic, the third protrusion is spaced apart from the two side walls of the groove, and the ratio of the width d3 of the third protrusion to the width w of the groove is in the range of: 0.7≤d3 / w≤0.

9.

9. The energy storage device according to claim 8, characterized in that: The lower plastic also includes a fourth protrusion, which is protruding from the surface of the bottom wall of the sink, and along the thickness direction of the end cover assembly, the height of the fourth protrusion is less than the height of the second protrusion; Along the length direction of the end cover assembly, the fourth protrusion is located between the second protrusion and the second side surface, and along the width direction of the end cover assembly, the fourth protrusion is spaced apart from the two side walls of the groove, and the ratio range of the width d4 of the fourth protrusion to the width w of the groove is: 0.7≤d4 / w≤0.

9.

10. The energy storage device according to claim 9, characterized in that: The volume of the first protrusion is equal to the volume of the second protrusion, and the volume of the third protrusion is equal to the volume of the fourth protrusion; The lower plastic also includes a fifth protrusion, which is protruded from the surface of the bottom wall of the sink, and is located between the second protrusion and the fourth protrusion along the length direction of the end cover assembly. The fifth protrusion is spaced apart from the second protrusion and the fourth protrusion, and the height of the fifth protrusion is less than the height of the second protrusion along the thickness direction of the end cover assembly; Along the width direction of the lower plastic, the fifth protrusion is spaced apart from the two side walls of the sink, and the ratio of the width d5 ​​of the fifth protrusion to the width w of the sink is in the range of 0.7≤d5 / w≤0.

9.

11. The energy storage device according to claim 10, characterized in that: The end cap is provided with a liquid injection hole, which penetrates the end cap along the thickness direction of the end cap assembly, and the lower plastic also includes a liquid injection through hole, which penetrates the first surface and the second surface along the thickness direction of the lower plastic, and is located between the fourth protrusion and the fifth protrusion along the length direction of the lower plastic; Along the thickness direction of the end cover assembly, the injection hole is opposite to and connected with the injection through hole.

12. The energy storage device according to claim 7, characterized in that: The lower plastic also includes two convex ribs, both of which are convexly arranged on the second surface. Along the width direction of the end cover assembly, the two convex ribs are respectively connected to the opposite sides of the lower plastic body. Along the length direction of the end cover assembly, the lengths of the two convex ribs are equal to the length of the lower plastic body. Along the thickness direction of the end cover assembly, the two convex ribs are protruding from the first protrusion. Along the width direction of the energy storage device, the two convex ribs are respectively located on opposite sides of the electrode assembly, and the two convex ribs are spaced apart from the electrode assembly.

13. The energy storage device according to claim 7, characterized in that: The lower plastic includes a limiting convex portion, and along the thickness direction of the end cover assembly, the sink groove is convexly provided on the first surface to form the limiting convex portion, and the limiting convex portion includes a concave surface; The lower plastic is further provided with a first groove and a second groove, wherein the first groove is concavely provided on the surface of the groove bottom wall of the sink groove facing the concavely provided, and the first protrusion is convexly provided on the surface of the groove bottom wall of the sink groove, and the second groove is concavely provided on the surface of the groove bottom wall of the sink groove facing the concavely provided, and the second protrusion is convexly provided on the surface of the groove bottom wall of the sink groove; The end cover further includes a first mounting surface and a second mounting surface arranged opposite to the first mounting surface, the end cover is provided with a mounting groove, along the thickness direction of the end cover, the mounting groove is concavely arranged from the second mounting surface to the first mounting surface, and convexly arranged on the first mounting surface to form a convex bump, the convex bump includes a stamping surface, and the explosion-proof hole penetrates the bottom wall of the mounting groove; The end cover is provided with a first recess and a second recess, the first recess is recessed by the punching surface facing the groove bottom wall of the mounting groove, and a first protrusion is convexly provided on the surface of the groove bottom wall of the mounting groove, and the shape of the first protrusion matches the first groove, the second recess is recessed by the punching surface facing the groove bottom wall of the mounting groove, and a second protrusion is convexly provided on the surface of the groove bottom wall of the mounting groove, and the shape of the second protrusion matches the second groove; The limiting protrusion is limited in the installation groove, the first protrusion is limited in the first groove, and the second protrusion is limited in the second groove.

14. The energy storage device according to claim 13, characterized in that: The first convex portion includes a first sub-convex portion and a second sub-convex portion, the second sub-convex portion is convexly arranged on a surface of the first sub-convex portion facing away from the first mounting surface, and along the thickness direction of the end cover assembly, the orthographic projection of the second sub-convex portion on the first surface is located within the orthographic projection of the first sub-convex portion; The second protrusion includes a third sub-protrusion and a fourth sub-protrusion. The fourth sub-protrusion is protruding from the surface of the third sub-protrusion facing away from the first mounting surface. Along the thickness direction of the end cover assembly, the orthographic projection of the fourth sub-protrusion on the first mounting surface is located within the orthographic projection of the third sub-protrusion.

15. The energy storage device according to any one of claims 1 to 14, characterized in that: The lower plastic includes a first lower plastic and a second lower plastic, the first side surface is located on the first lower plastic, the second side surface is located on the second lower plastic, and along the length direction of the end cover assembly, the vent hole is located at an end of the second lower plastic away from the second side surface, and the end of the first lower plastic away from the first side surface is opposite to an end of the second lower plastic away from the second side surface.

16. An electrical equipment, characterized in that: It comprises an energy storage device as described in any one of claims 1 to 15, wherein the energy storage device is used to store electrical energy.

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