Energy storage devices, energy storage modules and electrical equipment

Abstract

The present application provides an energy storage device, an energy storage module and an electrical device, which can ensure smooth exhaust of the energy storage device, ensure that the explosion-proof valve cannot open the valve to release pressure in time, and improve the safety of the energy storage device. The energy storage device includes a shell, an electrode assembly and a cover plate, the electrode assembly is accommodated in the accommodating cavity of the shell, the cover plate is installed on the shell and closes the opening of the shell, the cover plate includes a main body and a boss portion, the main body includes a first surface and a second surface arranged opposite to each other, the boss portion is fixedly connected to the main body and protrudes relative to the first surface, the boss portion includes a first surface away from the electrode assembly and a second surface arranged opposite to the first surface, the second surface is convexly provided with at least one first sub-protrusion, at least one first sub-protrusion is spaced apart from the explosion-proof hole of the boss portion, along the height direction of the energy storage device, the surface of at least one first sub-protrusion facing the electrode assembly is located on the side of the second surface away from the first surface, and at least one first sub-protrusion is arranged opposite to the electrode assembly.

Description

Technical Field

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

[0002] Energy storage devices such as secondary batteries are widely used as the main power source for electrical equipment due to their recyclable characteristics. As the demand for energy storage devices gradually increases, people's performance requirements for them in various aspects are also getting higher and higher. When a thermal runaway occurs in an energy storage device, gas will be generated inside the energy storage device. The reel of the energy storage device is easily driven by the gas to move toward the top cover and abut against the top cover, blocking the exhaust channel between the reel and the top cover, making the exhaust of the energy storage device not smooth, resulting in the explosion-proof valve on the top cover unable to open the valve to release pressure in time, reducing the safety of the energy storage device. Summary of the invention

[0003] The present application provides an energy storage device, an energy storage module and electrical equipment, which can ensure smooth exhaust of the energy storage device, ensure that the explosion-proof valve cannot open the valve to release pressure in time, and improve the safety of the energy storage device.

[0004] In a first aspect, the present application provides an energy storage device. The energy storage device includes a shell, an electrode assembly and a cover plate, the shell having an opening and a receiving cavity, the opening communicating with the receiving cavity, the electrode assembly being received in the receiving cavity, the cover plate being mounted on the shell and closing the opening, the cover plate including a main body and a boss portion, the main body including a first surface and a second surface, the first surface and the second surface being disposed opposite to each other along the thickness direction of the main body, the boss portion being fixedly connected to the main body and protruding relative to the first surface, the boss portion including a first surface facing away from the electrode assembly and a second surface being disposed opposite to the first surface, the first surface and the second surface being both located on the side of the first surface facing away from the second surface, the boss portion being provided with an explosion-proof hole, the explosion-proof hole penetrating the first surface and the second surface along the thickness direction of the boss portion, the second surface being provided with at least one first sub-protrusion, to At least one of the first sub-protrusions is spaced from the explosion-proof hole, along the height direction of the energy storage device, the surface of at least one of the first sub-protrusions facing the electrode assembly is located on the side of the second surface away from the first surface, and at least one of the first sub-protrusions is arranged opposite to the electrode assembly, and at least one second sub-protrusion is also convexly provided on the surface of the first sub-protrusion facing the electrode assembly, along the height direction of the energy storage device, at least one of the second sub-protrusions is arranged opposite to the electrode assembly, the cover plate is further provided with at least one recess, and the opening of at least one recess faces the side of the cover plate away from the electrode assembly, along the thickness direction of the cover plate, at least one recess is arranged opposite to the first sub-protrusion and the second sub-protrusion, and along the thickness direction of the cover plate, the distance d2 between the bottom wall of at least one recess and the first surface is within 0.1 The recess comprises a first groove and a second groove, the opening of the first groove faces the side of the cover plate away from the electrode assembly, and along the thickness direction of the cover plate, the first groove is arranged opposite to the first sub-protrusion, the first groove comprises a first groove bottom wall, the opening of the second groove faces the first groove bottom wall, and the second groove is connected to the first groove, along the thickness direction of the cover plate, the second groove is arranged opposite to the second sub-protrusion, the second groove comprises a second groove bottom wall, and the second groove bottom wall is the groove bottom wall of the recess.

[0005] There are a plurality of the first sub-protrusions, and along the length direction of the cover plate, the plurality of the first sub-protrusions are respectively arranged on two opposite sides of the explosion-proof hole and are spaced apart from each other.

[0006] There are a plurality of second sub-protrusions, and each of the second sub-protrusions is protruding from a surface of the first sub-protrusion facing the electrode assembly.

[0007] Wherein, along the thickness direction of the cover plate, a ratio of a distance d1 between a surface of at least one of the first sub-protrusions facing the electrode assembly and the first surface to the thickness of the cover plate is between 2 and 3.

[0008] Among them, along the thickness direction of the cover plate, the ratio of the distance d3 between the first groove bottom wall and the first surface to the thickness of the cover plate is less than or equal to 2, and the ratio of the distance d4 between the second groove bottom wall and the first groove bottom wall to the thickness of the cover plate is less than or equal to 2.

[0009] The boss portion is further provided with a liquid injection hole, which penetrates the first surface and the second surface along the thickness direction of the boss portion, and is spaced apart from the explosion-proof hole and the first sub-protrusion.

[0010] Among them, the energy storage device also includes an explosion-proof valve and a lower plastic, the explosion-proof valve is installed on the boss portion and connected to the explosion-proof hole, the lower plastic is installed on the side of the second surface away from the first surface, the lower plastic is provided with an explosion-proof fence and at least one avoidance groove, the explosion-proof fence penetrates the lower plastic along the thickness direction of the lower plastic, along the height direction of the energy storage device, the explosion-proof fence is arranged opposite to and connected to the explosion-proof hole, the opening of at least one avoidance groove is arranged toward the cover plate, at least one avoidance groove is spaced apart from the explosion-proof fence, and at least one avoidance groove avoids the first sub-protrusion and the second sub-protrusion.

[0011] Wherein, the lower plastic is also provided with reinforcing ribs, and the reinforcing ribs are arranged on a side away from the explosion-proof fence and away from the explosion-proof hole.

[0012] In a second aspect, the present application also provides an energy storage module, comprising an electrical connection plate, a wiring harness isolation plate and an energy storage device as described in any of the above items, wherein the electrical connection plate and the wiring harness isolation plate are both located on one side in the height direction of the energy storage device, wherein the electrical connection plate is electrically connected to the energy storage device.

[0013] Among them, the main body is also provided with an assembly hole, and the assembly hole passes through the main body along the thickness direction of the main body; the energy storage device also includes a pole, and the pole is penetrated by the assembly hole; the wiring harness isolation plate is installed on the side of the boss away from the main body, and the wiring harness isolation plate is provided with a mounting groove, and the opening of the mounting groove faces the side of the wiring harness isolation plate away from the boss, and the bottom wall of the mounting groove is provided with an avoidance hole, and along the thickness direction of the bottom wall of the mounting groove, the avoidance hole passes through the bottom wall of the mounting groove, and the avoidance hole avoids the pole; the electrical connecting piece is installed in the mounting groove and electrically connected to the pole, and the electrical connecting piece includes two first parts and a second part, along the length direction of the electrical connecting piece, the two first parts are spaced apart, the first part is electrically connected to the pole, the second part is fixedly connected between the two first parts, and protrudes relative to the surface of the first part away from the pole, and along the height direction of the energy storage module, the surface of the second part away from the pole is flush with the surface of the wiring harness isolation plate away from the boss.

[0014] In a third aspect, the present application further provides an electrical device, comprising an energy storage module as described in any one of the above items, wherein the energy storage module supplies power to the electrical device.

[0015] In the technical solution provided by the present application, by arranging the first sub-protrusion and the second sub-protrusion on the boss portion, when the energy storage device has thermal runaway, the first sub-protrusion and the second sub-protrusion can abut against the electrode assembly of the energy storage device, so that a certain gap can be left between the electrode assembly and the boss portion, so as to avoid the exhaust passage between the electrode assembly and the cover plate from being blocked, and ensure smooth exhaust of the energy storage device, so as to ensure that the explosion-proof valve on the cover plate opens the valve to release pressure in time, and avoids the explosion of the energy storage device, which is beneficial to improve the safety performance of the energy storage device. At the same time, the explosion-proof hole of the boss portion of the explosion-proof valve installed on the cover plate can increase the distance between the explosion-proof valve and the electrode assembly, prevent the exhaust caused by the explosion-proof valve being too low, and ensure that all the gas inside the energy storage device can be discharged smoothly, so as to avoid safety accidents caused by poor exhaust, so as to further improve the safety performance of the energy storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0017] Figure 1 It is a structural schematic diagram of the energy storage module provided in the embodiment of the present application;

[0018] Figure 2 yes Figure 1 An enlarged schematic diagram of region A is shown;

[0019] Figure 3 yes Figure 2 A schematic diagram of the structure of the energy storage device and the wiring harness isolation plate;

[0020] Figure 4 yes Figure 1 A schematic diagram of the structure of the energy storage device in the energy storage module shown;

[0021] Figure 5 yes Figure 4 A schematic diagram of the exploded structure of the energy storage device shown;

[0022] Figure 6 yes Figure 4 The schematic diagram of the cross-sectional structure of the energy storage device shown is cut along BB;

[0023] Figure 7 yes Figure 4 A schematic diagram of the structure of the end cover assembly in the energy storage device shown;

[0024] Figure 8 yes Figure 7 An exploded structural diagram of the end cap assembly shown;

[0025] Fig. 9 yes Figure 8 A schematic diagram of the structure of the lower plastic in the end cover assembly shown at another angle;

[0026] Fig.10 yes Figure 4 A schematic diagram of the structure of the cover plate in the end cover assembly shown;

[0027] Fig.11 yes Fig.10 The structural schematic diagram of the cover plate shown at another angle;

[0028] Fig.12 yes Fig.10 The cross-sectional structure diagram of the cover plate after being cut along CC;

[0029] Fig.13 yes Figure 8 A schematic diagram of the exploded structure of the pole unit in the end cover assembly shown;

[0030] Fig.14 yes Fig.13 Schematic diagram of the structure of the upper plastic in the pole unit shown.

[0031] The names corresponding to the reference numerals in the figures are:

[0032] Energy storage module 1000, first direction X, second direction Y, third direction Z, energy storage device 100, electrical connection sheet 200, wiring harness isolation plate 300, collection harness 400, installation groove 310, assembly groove 320, avoidance gap 330, avoidance hole 311, first part 210, second part 220, shell 110, electrode assembly 120, end cover assembly 130, opening 111, receiving cavity 112, lower plastic 10, cover plate 20, explosion-proof valve 30, pole unit 40, third surface 11, fourth surface 12, explosion-proof fence 101, liquid inlet hole 102, through hole 103, avoidance groove 104, first sub-groove 1041, second sub-groove 1042, second protrusion 105, The third sub-protrusion 1051, the fourth sub-protrusion 1052, the reinforcing rib 106, the main body 21, the boss portion 22, the first surface 211, the second surface 212, the assembly hole 213, the first surface 221, the second surface 222, the explosion-proof hole 223, the injection hole 224, the recess 225, the first groove 2251, the second groove 2252, the first groove bottom wall 2251a, the second groove bottom wall 2252a, the first protrusion 226, the first sub-protrusion 2261, the second sub-protrusion 2262, the upper plastic 41, the pole 42, the seal 43, the adapter 44, the plastic main body 411, the extension portion 412, the matching groove 413, the mounting hole 414, the flange portion 421, and the column portion 422. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0034] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of the energy storage module 1000 provided in the embodiment of the present application. For the convenience of description, the length direction of the energy storage module 1000 is defined as the first direction X, the width direction of the energy storage module 1000 is defined as the second direction Y, and the height direction of the energy storage module 1000 is defined as the third direction Z. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0035] In this embodiment, the energy storage module 1000 includes a plurality of energy storage devices 100, a plurality of electrical connection sheets 200, a wiring harness isolation plate 300, and a collection harness 400. Specifically, the plurality of electrical connection sheets 200 and the wiring harness isolation plate 300 are installed on the plurality of energy storage devices 100. Among them, the plurality of electrical connection sheets 200 are electrically connected to the plurality of energy storage devices 100. The collection harness 400 is installed on the wiring harness isolation plate 300 and is electrically connected to the plurality of electrical connection sheets 200. The collection harness 400 can be used to collect parameters such as voltage and temperature of the energy storage device 100.

[0036] Specifically, along the first direction X, multiple energy storage devices 100 are arranged in sequence. In this embodiment, multiple energy storage devices 100 can be arranged in series, or multiple energy storage devices 100 can be arranged in parallel, or, among the multiple energy storage devices 100, some energy storage devices 100 can be arranged in series, and some energy storage devices 100 can be arranged in parallel. The embodiment of the present application does not impose specific restrictions on the connection method of multiple energy storage devices 100 in the energy storage device 100. In addition, the capacity of each energy storage device 100 is between 500 Ah and 3000 Ah. The width of each energy storage device 100 is between 50 mm and 150 mm, the height is between 150 mm and 400 mm, and the length is between 300 mm and 1200 mm.

[0037] Please refer to Figure 2 and Figure 3 , Figure 2 yes Figure 1 The enlarged schematic diagram of area A is shown. Figure 3 yes Figure 2 Schematic diagram of the structure of the energy storage device 100 and the wiring harness isolation plate 300.

[0038] In this embodiment, the harness isolation plate 300 and the plurality of electrical connection sheets 200 are all located on the same side in the height direction (the third direction Z shown in the figure) of the plurality of energy storage devices 100. The harness isolation plate 300 exposes part of the energy storage device 100 so as to facilitate electrical connection between the energy storage device 100 and the electrical connection sheet 200. Specifically, the harness isolation plate 300 is provided with a mounting groove 310, an assembly groove 320 and an avoidance gap 330. The openings of the mounting groove 310 and the assembly groove 320 are both arranged toward the side of the harness isolation plate 300 away from the energy storage device 100. The mounting groove 310 and the assembly groove 320 are both recessed from the surface of the harness isolation plate 300 away from the energy storage device 100 toward the direction of the energy storage device 100. The mounting groove 310 is used to install the electrical connection sheet 200. The bottom wall of the mounting groove 310 is provided with an avoidance hole 311, and the avoidance hole 311 penetrates the bottom wall of the mounting groove 310 along the thickness direction of the bottom wall of the mounting groove 310. The avoidance hole 311 is used to avoid the pole 42 of the energy storage device 100, so as to facilitate the electrical connection between the energy storage device 100 and the electrical connection sheet 200. The assembly groove 320 is arranged at a distance from the installation groove 310. The assembly groove 320 is used to install the collection harness 400.

[0039] The avoidance gap 330 is provided between the installation groove 310 and the assembly groove 320. Specifically, the opening of the avoidance gap 330 is located on the surface of the harness isolation plate 300 away from the energy storage device 100. The avoidance gap 330 is recessed from the surface of the harness isolation plate 300 away from the energy storage device 100 toward the energy storage device 100, and penetrates the groove side wall of the installation groove 310 and the groove side wall of the assembly groove 320, so that the subsequent collection harness 400 extends into the installation groove 310 through the avoidance gap 330, so that the collection harness 400 is electrically connected to the electrical connection sheet 200.

[0040] In this embodiment, there are multiple installation grooves 310, assembly grooves 320 and avoidance gaps 330. In particular, along the length direction of the energy storage module 1000 (the first direction X in the figure), multiple installation grooves 310 are arranged at intervals, and multiple assembly grooves 320 are located between multiple installation grooves 310, and are arranged at intervals along the width direction of the energy storage module 1000 (the second direction Y in the figure). Each avoidance gap 330 is located between a installation groove 310 and an assembly groove 320.

[0041] Each electrical connection sheet 200 is installed in a mounting groove 310, and electrically connects two adjacent energy storage devices 100, so that multiple energy storage devices 100 are connected in series or in parallel. In this embodiment, each electrical connection sheet 200 includes two first parts 210 and a second part 220. Along the length direction of the electrical connection sheet 200, the two first parts 210 are arranged at intervals. The second part 220 is fixedly connected between the two first parts 210, and protrudes from the surface of the energy storage device 100 relative to the first part 210. Specifically, the first part 210 is electrically connected to the energy storage device 100, and the second part 220 is electrically connected to the collection harness 400, so that the collection harness 400 can collect parameters such as voltage and temperature of the energy storage device 100.

[0042] The collection harness 400 is arranged on the side of the harness isolation plate 300 away from the multiple energy storage devices 100. Specifically, part of the collection harness 400 is installed in the assembly groove 320. Part of the collection harness 400 is passed through the avoidance gap 330, extends into the installation groove 310, and is electrically connected to the electrical connection piece 200. Under this setting, the collection harness 400 can be separated from the energy storage device 100 by the harness isolation plate 300 made of plastic material, thereby avoiding the short circuit problem caused by the contact between the collection harness 400 and the energy storage device 100. Exemplarily, the collection harness 400 is a harness FPC (Flexible Printed Circuit). It should be noted that the wiring harness FPC in the energy storage module 1000 is a printed circuit board made of a flexible copper-clad laminate as a substrate. It is mainly responsible for information collection and transmission in the energy storage module 1000, and the wiring harness FPC also has an overcurrent protection function, which helps to protect the energy storage device 100 of the energy storage module 1000 from abnormal short circuits.

[0043] See also Figure 4 , Figure 5 and Figure 6 , Figure 4 yes Figure 1 The schematic diagram of the structure of the energy storage device 100 in the energy storage module 1000 is shown. Figure 5 yes Figure 4 The schematic diagram of the exploded structure of the energy storage device 100 is shown in FIG. Figure 6 yes Figure 4 The cross-sectional structure diagram of the energy storage device 100 is shown after being cut along line BB. Herein, “cut along line BB” means cutting along the plane where line BB is located, and similar descriptions in the following text can be understood in the same way.

[0044] In this embodiment, the energy storage device 100 includes a shell 110, an electrode assembly 120 and an end cap assembly 130. The shell 110 has an opening 111 and a receiving cavity 112, and the opening 111 is connected to the receiving cavity 112. The electrode assembly 120 is received in the receiving cavity 112. The receiving cavity 112 is also used to receive the electrolyte, and the electrode assembly 120 is immersed in the electrolyte. The end cap assembly 130 is installed on one side of the shell 110 in the height direction of the energy storage device 100 (the third direction Z shown in the figure), and closes the opening 111. Exemplarily, the energy storage device 100 is a square battery. Among them, the width direction of the energy storage device 100 is parallel to the first direction X, the length direction of the energy storage device 100 is parallel to the second direction Y, and the height direction of the energy storage device 100 is parallel to the third direction Z. In some other embodiments, the energy storage device 100 can also be a cylindrical battery or other batteries.

[0045] Please refer to Figure 6 , Figure 7 and Figure 8 , Figure 7 yes Figure 4 The schematic diagram of the structure of the end cover assembly 130 in the energy storage device 100 is shown. Figure 8 yes Figure 7 A schematic diagram of the exploded structure of the end cap assembly 130 is shown.

[0046] The end cap assembly 130 includes a lower plastic 10, a cover plate 20, an explosion-proof valve 30 and two pole units 40. The lower plastic 10 is installed on one side of the thickness direction of the cover plate 20. The explosion-proof valve 30 and the two pole units 40 are both installed on the cover plate 20. In the length direction of the energy storage device 100, the two pole units 40 are respectively located on opposite sides of the explosion-proof valve 30.

[0047] Please refer to Figure 8 and Fig. 9 , Fig. 9 yes Figure 8 The structure diagram of the lower plastic 10 in the end cover assembly 130 is shown at another angle.

[0048] The lower plastic 10 includes a third surface 11 and a fourth surface 12, and the third surface 11 and the fourth surface 12 are arranged opposite to each other along the thickness direction (the third direction Z shown in the figure) of the lower plastic 10. The lower plastic 10 also includes an explosion-proof fence 101, and the explosion-proof fence 101 penetrates the third surface 11 and the fourth surface 12 of the lower plastic 10. In this embodiment, the explosion-proof fence 101 is located in the middle of the lower plastic 10.

[0049] The lower plastic 10 is also provided with a liquid inlet hole 102, a through hole 103 and at least one avoidance groove 104. Among them, the liquid inlet hole 102 and the through hole 103 both penetrate the third surface 11 and the fourth surface 12 of the lower plastic 10 along the thickness direction of the lower plastic 10 (the third direction Z axis shown in the figure), and are spaced apart from each other and spaced apart from the explosion-proof fence 101. Specifically, along the length direction of the energy storage device 100 (the second direction Y shown in the figure), the liquid inlet hole 102 is located on one side of the explosion-proof fence 101. In this embodiment, along the length direction of the energy storage device 100 (the second direction Y shown in the figure), the through hole 103 is located at the edge of the lower plastic 10. Exemplarily, there are two through holes 103. Specifically, one through hole 103 is located on the side of the explosion-proof fence 101 away from the liquid inlet hole 102, and the other through hole 103 is located on the side of the liquid inlet hole 102 away from the explosion-proof fence 101.

[0050] At least one avoidance groove 104 is spaced apart from the explosion-proof fence 101, the liquid inlet 102 and the through hole 103. In this embodiment, the opening of at least one avoidance groove 104 is disposed toward the cover plate 20, and the avoidance groove 104 is recessed from the third surface 11 toward the fourth surface 12.

[0051] In this embodiment, there are two avoidance grooves 104. Along the length direction of the lower plastic 10 (the second direction Y shown in the figure), the two avoidance grooves 104 are spaced apart on opposite sides of the explosion-proof fence 101. Specifically, one avoidance groove 104 is located between the explosion-proof fence 101 and a through hole 103, and the other avoidance groove 104 is located between the explosion-proof fence 101 and the liquid inlet hole 102. In this embodiment, each avoidance groove 104 includes a first sub-groove 1041 and a second sub-groove 1042, and the second sub-groove 1042 is located on one side of the first sub-groove 1041 and is connected to the first sub-groove 1041. Among them, the opening of the first sub-groove 1041 is located on the third surface 11, and the opening of the second sub-groove 1042 is located on the bottom wall of the first sub-groove 1041.

[0052] In this embodiment, the lower plastic 10 is further provided with a second protrusion 105. The second protrusion 105 can be used to abut the electrode assembly 120 to limit the electrode assembly 120. Specifically, the second protrusion 105 is provided on the fourth surface 12, and protrudes in a direction away from the fourth surface 12 along the thickness direction of the lower plastic 10. Along the thickness direction of the lower plastic 10, the second protrusion 105 is arranged opposite to the avoidance groove 104. That is, along the thickness direction of the lower plastic 10, the projection of the second protrusion 105 on the lower plastic 10 is located in the avoidance groove 104.

[0053] Specifically, the second protrusion 105 includes a third sub-protrusion 1051 and a fourth sub-protrusion 1052 connected to each other. Specifically, the third sub-protrusion 1051 is disposed on the fourth surface 12, and the fourth sub-protrusion 1052 is disposed on the surface of the third sub-protrusion 1051 away from the fourth surface 12. The peripheral surface of the third sub-protrusion 1051 protrudes relative to the peripheral surface of the fourth sub-protrusion 1052. Along the thickness direction of the lower plastic 10, the third sub-protrusion 1051 is disposed opposite to the first sub-groove 1041, and the fourth sub-protrusion 1052 is disposed opposite to the second sub-groove 1042. In addition, in this embodiment, the second protrusion 105 can be formed by stamping the lower plastic 10 from the third surface 11 of the lower plastic 10 toward the fourth surface 12, and the avoidance groove 104 is formed on the third surface 11. That is, the third sub-protrusion 1051 of the second protrusion 105 and the first sub-groove 1041 of the avoidance groove 104 are formed simultaneously during a stamping process, and the fourth sub-protrusion 1052 of the second protrusion 105 and the second sub-groove 1042 of the avoidance groove 104 are formed simultaneously during a stamping process, thereby simplifying the manufacturing process of the lower plastic 10 and reducing the production cost of the lower plastic 10.

[0054] In this embodiment, there can be multiple second protrusions 105, and the multiple second protrusions 105 are arranged at intervals from each other. Exemplarily, there are two second protrusions 105. Along the length direction of the lower plastic 10, the two second protrusions 105 are arranged at intervals on opposite sides of the explosion-proof fence 101. Specifically, one second protrusion 105 is arranged on the side of the explosion-proof fence 101 away from the liquid inlet hole 102, and the other second protrusion 105 is arranged between the explosion-proof fence 101 and the liquid inlet hole 102. In some other embodiments, the number of the second protrusions 105 can also be one, three, or more than three.

[0055] In addition, in this embodiment, the lower plastic 10 is also provided with a reinforcing rib 106. The reinforcing rib 106 is provided on the side of the explosion-proof fence 101 away from the cover plate 20. Exemplarily, there are multiple reinforcing ribs 106. Along the length direction of the lower plastic 10, multiple reinforcing ribs 106 are arranged at intervals. It can be understood that when the energy storage device 100 is thermally runaway, under the action of air pressure, the arching degree of the position where the explosion-proof fence 101 is provided in the lower plastic 10 is severe. By providing the reinforcing rib 106 and making the reinforcing rib 106 relative to the explosion-proof fence 101, the structural strength of the part of the lower plastic 10 where the explosion-proof fence 101 is provided can be increased, and the arching degree of the position where the explosion-proof fence 101 is provided in the lower plastic 10 can be weakened, so that the exhaust channel between the lower plastic 10 and the cover plate 20 can be avoided from being compressed, and the gas inside the energy storage device 100 can be ensured to be discharged smoothly, so as to prevent the energy storage device 100 from exploding, thereby helping to improve the safety and reliability of the energy storage device 100.

[0056] Please refer to Fig.10 , Fig.11 and Fig.12 , Fig.10 yes Figure 4 The structural schematic diagram of the cover plate 20 in the end cover assembly 130 is shown. Fig.11 yes Fig.10 The structural schematic diagram of the cover plate 20 at another angle is shown. Fig.12 yes Fig.10 The cover plate 20 is shown as a schematic cross-sectional structure diagram after being cut along CC.

[0057] In this embodiment, the cover plate 20 includes a main body 21 and a boss portion 22. In this embodiment, the main body 21 and the boss portion 22 are integrally formed. Exemplarily, the main body 21 and the boss portion 22 can be integrally formed by a stamping process. Specifically, the main body 21 includes a first surface 211 and a second surface 212. Along the thickness direction of the main body 21, the first surface 211 and the second surface 212 are arranged opposite to each other. Among them, the first surface 211 is the surface of the main body 21 away from the lower plastic 10, and the second surface 212 is the surface of the main body 21 facing the lower plastic 10. The main body 21 is also provided with an assembly hole 213. The assembly hole 213 passes through the main body 21 along the thickness direction of the main body 21. In this embodiment, there are two assembly holes 213. Along the length direction of the cover plate 20, the two assembly holes 213 are arranged at intervals. Each assembly hole 213 is connected to a through hole 103 of the lower plastic 10 to facilitate the installation of the pole unit 40.

[0058] In this embodiment, the boss portion 22 is located at the center of the cover plate 20. The boss portion 22 is fixedly connected to the main body 21 and protrudes relative to the first surface 211. The boss portion 22 also extends along the length direction of the cover plate 20 (the second direction Y shown in the figure). Specifically, the boss portion 22 includes a first surface 221 away from the electrode assembly 120 and a second surface 222 disposed opposite to the first surface 221. In this embodiment, the first surface 221 and the second surface 222 are both located on the side of the first surface 211 away from the second surface 212.

[0059] The boss portion 22 is provided with an explosion-proof hole 223, an injection hole 224 and at least one recess 225. Among them, the explosion-proof hole 223 and the injection hole 224 both penetrate the first surface 221 and the second surface 222 of the boss portion 22 along the thickness direction of the boss portion 22, and are arranged at intervals from each other. In this embodiment, the explosion-proof hole 223 is located in the middle of the boss portion 22. That is, the explosion-proof hole 223 is located between the two assembly holes 213. In this embodiment, the explosion-proof hole 223 is arranged opposite to and connected to the explosion-proof fence 101 of the lower plastic 10. The explosion-proof hole 223 can be connected to the interior of the energy storage device 100 through the explosion-proof fence 101. Among them, a reinforcing rib 106 is provided on the side of the explosion-proof fence 101 away from the explosion-proof hole 223. In addition, the area where the explosion-proof hole 223 is provided on the boss portion 22 of the cover plate 20 is a stress-weakened area, which can play a stress isolation effect and avoid excessive stress concentration on the cover plate 20, thereby preventing the cover plate 20 from rupturing due to excessive stress concentration when impacted by the gas inside the energy storage device 100, thereby helping to ensure that the cover plate 20 has good reliability in use.

[0060] Along the length direction of the cover plate 20 (the second direction Y in the figure), the injection hole 224 is located between the explosion-proof hole 223 and an assembly hole 213. The injection hole 224 is connected to the liquid inlet hole 102 of the lower plastic 10. The electrolyte can be injected into the receiving cavity 112 (such as the liquid inlet hole 102) of the shell 110 through the injection hole 224 of the cover plate 20 and the liquid inlet hole 102 of the lower plastic 10 in sequence. Figure 5 ) to achieve the perfusion of the electrolyte of the energy storage device 100. At the same time, by arranging the injection hole 224 on the boss portion 22 of the cover plate 20, it is possible to prevent the electrolyte from directly impacting the electrode assembly 120 when it is injected into the receiving cavity of the shell through the injection hole 224, thereby preventing the active material on the electrode assembly 120 from falling due to being washed by the electrolyte, and also provide a larger injection space for injecting the electrolyte, so as to facilitate the flow of the electrolyte, thereby facilitating the electrolyte to completely infiltrate the electrode assembly 120.

[0061] In this embodiment, at least one recess 225 is arranged near the explosion-proof hole 223, and is spaced from the explosion-proof hole 223 and the injection hole 224. Specifically, the opening of the recess 225 is toward the side of the cover plate 20 away from the electrode assembly 120, and the recess 225 is recessed from the first surface 221 to the main body 21. In the thickness direction of the cover plate 20, the distance d2 between the bottom wall of the recess 225 and the first surface 221 is between 0.1 mm and 30 mm, so as to prevent the cover plate 20 from being broken during the formation of the recess 225, thereby ensuring that the overall structural strength of the cover plate 20 is relatively large, and ensuring that the cover plate 20 has good reliability in use.

[0062] Specifically, the recess 225 includes a first groove 2251 and a second groove 2252, and the first groove 2251 and the second groove 2252 are connected. Specifically, the opening of the first groove 2251 is toward the side of the cover plate 20 away from the electrode assembly 120, and the first groove 2251 is recessed from the first surface 221 to the main body 21. Among them, the first groove 2251 includes a first groove bottom wall 2251a. Along the thickness direction of the cover plate 20, the ratio of the distance d3 between the first groove bottom wall 2251a and the first surface 221 to the thickness of the cover plate 20 is less than or equal to 2. The opening of the second groove 2252 is toward the first groove bottom wall 2251a, and the second groove 2252 is recessed from the first groove bottom wall 2251a to the direction away from the first surface 221. Among them, the second groove 2252 includes a second groove bottom wall 2252a. Along the thickness direction of the cover plate 20, the distance d2 between the second groove bottom wall 2252a and the first surface 221 is between 0.1 mm and 30 mm, and the ratio of the distance d4 between the second groove bottom wall 2252a and the first groove bottom wall 2251a to the thickness of the cover plate 20 is less than or equal to 2. Under this arrangement, the cover plate 20 can be prevented from being broken during the process of forming the first groove 2251 and the second groove 2252, thereby ensuring that the overall structural strength of the cover plate 20 is relatively large and the reliability of the cover plate 20 is relatively good.

[0063] In this embodiment, there are at least two first grooves 2251 and at least two second grooves 2252. Among them, along the length direction of the cover plate 20, at least two first grooves 2251 are respectively arranged on opposite sides of the explosion-proof hole 223, and are arranged at intervals from each other. Exemplarily, there are two recesses 225. Specifically, one first groove 2251 is arranged on the side of the explosion-proof hole 223 away from the injection hole 224, and the other first groove 2251 is arranged between the explosion-proof hole 223 and the injection hole 224. In some other embodiments, the number of first grooves 2251 can also be one, three or more, and the embodiments of the present application do not impose any restrictions on this. In this embodiment, the opening of each second groove 2252 is located on the first groove bottom wall 2251a of a first groove 2251. Exemplarily, there are two second grooves 2252. In some other embodiments, the number of second grooves 2252 can also be one, three or more, and the embodiments of the present application do not impose any restrictions on this.

[0064] The second surface 222 of the boss portion 22 is also provided with at least one first protrusion 226, and the first protrusion 226 is spaced apart from the explosion-proof hole 223 and the injection hole 224. It is understandable that when the electrode assembly 120 of the energy storage device 100 expands or the energy storage device 100 performs negative pressure injection, the first sunken protrusion 226 is provided on the boss portion 22, which can effectively absorb and disperse the stress generated in the energy storage device 100 due to the expansion of the electrode assembly 120 or the negative pressure injection, thereby significantly reducing the local deformation or damage of the cover plate 20 and improving the structural stability and service life of the cover plate 20.

[0065] Specifically, at least one first protrusion 226 includes a first sub-protrusion 2261 and a second sub-protrusion 2262 connected to each other. That is, at least one first sub-protrusion 2261 is convexly provided on the second surface of the cover plate 20, and at least one second sub-protrusion 2262 is convexly provided on the surface of at least one first sub-protrusion 2261 facing the electrode assembly 120. In this embodiment, at least one first sub-protrusion 2261 and at least one second sub-protrusion 2262 are arranged at intervals from the explosion-proof hole 223 and the injection hole 224. Among them, the peripheral surface of the first sub-protrusion 2261 protrudes relative to the peripheral surface of the second sub-protrusion 2262. Along the height direction of the energy storage device 100, at least one second sub-protrusion 2262 is arranged opposite to the electrode assembly 120.

[0066] In addition, the ratio of the distance d1 between the surface of at least one first sub-protrusion 2261 facing the electrode assembly 120 and the first surface 221 to the thickness l of the cover plate 20 is between 2 and 3. Under this setting, a height difference can be created between the surface of the first sub-protrusion 2261 facing the electrode assembly 120 and the first surface 221 of the boss portion 22, thereby providing a space for the gathering of gas inside the energy storage device 100, so that the gas inside the energy storage device 100 can gather in this space. At the same time, this space is arranged close to the explosion-proof hole 223, which is also conducive to the discharge of gas inside the energy storage device 100 from the explosion-proof hole 223.

[0067] In this embodiment, along the thickness direction of the cover plate 20, the first sub-protrusion 2261 and the second sub-protrusion 2262 of the first protrusion 226 are arranged opposite to the recess 225. That is, along the thickness direction of the cover plate 20, the projections of the first sub-protrusion 2261 and the second sub-protrusion 2262 of the first protrusion 226 on the boss portion 22 are both located in the recess 225. Specifically, along the thickness direction of the cover plate 20, the first sub-protrusion 2261 of the first protrusion 226 is arranged opposite to the first groove 2251 of the recess 225, and the second sub-protrusion 2262 of the first protrusion 226 is arranged opposite to the second groove 2252 of the recess 225. Exemplarily, the first protrusion 226 can be formed by stamping the cover plate 20 from the surface of the boss portion 22 away from the main body 21 to the main body 21, and the recess 225 is formed on the surface of the boss portion 22 away from the main body 21. Specifically, the first sub-protrusion 2261 of the first protrusion 226 and the first groove 2251 of the recess 225 are formed simultaneously during a stamping process, and the second sub-protrusion 2262 of the first protrusion 226 and the second groove 2252 of the recess 225 are formed simultaneously during a stamping process, thereby simplifying the manufacturing process of the cover plate 20 and reducing the production cost of the cover plate 20.

[0068] In addition, in the process of forming the first protrusion 226 on the cover plate 20, the cover plate 20 can be first punched to form the first groove 2251 and the first sub-protrusion 2261, and then the bottom wall of the first groove 2251 can be punched to form the second groove 2252 and the second sub-protrusion 2262, so as to avoid excessive stretching of the cover plate 20 during stamping due to the large distance between the second bottom wall 2252a of the second groove 2252 and the first surface 221 of the boss portion 22, thereby preventing the cover plate 20 from breaking during the stamping process, which in turn helps to reduce the production loss of the cover plate 20 and save the production cost of the cover plate 20.

[0069] In this embodiment, there are multiple first sub-protrusions 2261 and multiple second sub-protrusions 2262. Among them, along the length direction of the cover plate 20 (the second direction Y shown in the figure), multiple first sub-protrusions 2261 are respectively arranged on opposite sides of the explosion-proof hole 223, and are arranged at intervals from each other. Along the thickness direction of the cover plate 20, each first sub-protrusion 2261 is arranged opposite to the first groove 2251 of a recess 225. Exemplarily, there are two first sub-protrusions 2261. Specifically, one first sub-protrusion 2261 is located on the side of the explosion-proof hole 223 away from the injection hole 224, and the other first sub-protrusion 2261 is located between the explosion-proof hole 223 and the injection hole 224. In some other embodiments, the number of first sub-protrusions 2261 can also be one, three or more than three, and the embodiments of the present application are not strictly limited to this. In this embodiment, each second sub-protrusion 2262 is convexly arranged on the surface of a first sub-protrusion 2261 facing the electrode assembly 120. Along the thickness direction of the cover plate 20, each second sub-protrusion 2262 is disposed opposite to a second groove 2252. Exemplarily, there are two second sub-protrusions 2262. In some other embodiments, the number of second sub-protrusions 2262 may be one, three, or more than three, and the embodiments of the present application are not strictly limited to this.

[0070] When the cover plate 20 is assembled with the lower plastic 10, each first protrusion 226 of the cover plate 20 is installed in an avoidance groove 104 of the lower plastic 10. Among them, each avoidance groove 104 avoids a first protrusion 226. Specifically, the first sub-protrusion 2261 of each first protrusion 226 is located in the first sub-groove 1041 of a avoidance groove 104, and is in contact with the bottom wall surface of the first sub-groove 1041. The second sub-protrusion 2262 of each first protrusion 226 is located in the second sub-groove 1042 of a avoidance groove 104, and is in contact with the bottom wall surface of the second sub-groove 1042. At this time, the first protrusion 226 of the cover plate 20 and the second protrusion 105 of the lower plastic 10 together constitute a rib structure. When the end cover assembly 130 is installed to the shell 110, the first sub-protrusion 2261 and the second sub-protrusion 2262 of the first protrusion 226 in the cover plate 20 are arranged opposite to the pole ear of the electrode assembly 120 in the shell 110, so that the rib structure formed by the first protrusion 226 of the cover plate 20 and the second protrusion 105 of the lower plastic 10 can limit the electrode assembly 120 to ensure that the exhaust channel between the electrode assembly 120 and the end cover assembly 130 is not blocked.

[0071] Please refer again Figure 7. The explosion-proof valve 30 is installed on the boss portion 22 and connected to the explosion-proof hole 223. In the present embodiment, the explosion-proof valve 30 is fixedly connected to the hole wall of the explosion-proof hole 223. Exemplarily, the explosion-proof valve 30 can be fixedly connected to the hole wall of the explosion-proof hole 223 by welding so as to be installed in the explosion-proof hole 223. It is understandable that since the explosion-proof hole 223 connects the inside and outside of the energy storage device 100, when the air pressure inside the energy storage device 100 is too high, the explosion-proof valve 30 will rupture under the action of the air pressure, and the gas inside the energy storage device 100 can be discharged to the outside of the energy storage device 100 in time through the explosion-proof fence 101 of the lower plastic 10 and the explosion-proof hole 223 in turn, thereby avoiding the explosion of the energy storage device 100 and improving the reliability of the use of the energy storage device 100.

[0072] In this embodiment, when the energy storage device 100 has thermal runaway, the electrode assembly 120 will be moved and arched toward the end cap assembly 130 driven by the airflow. At this time, the convex rib structure formed by the first protrusion 226 of the cover plate 20 and the second protrusion 105 of the lower plastic 10 can abut the electrode assembly 120, so that a certain gap can be left between the electrode assembly 120 and the boss portion 22 of the cover plate 20, so as to avoid the exhaust passage between the electrode assembly 120 and the end cap assembly 130 from being blocked, and ensure the smooth exhaust of the energy storage device 100, so as to ensure that the explosion-proof valve 30 is opened in time to release the pressure, and avoid the explosion of the energy storage device 100, which is conducive to improving the safety performance of the energy storage device 100. At the same time, the explosion-proof valve 30 is installed in the explosion-proof hole 223 of the boss portion 22 in the cover plate 20, which can increase the distance between the explosion-proof valve 30 and the electrode assembly 120, prevent exhaust obstruction caused by the explosion-proof valve 30 being positioned too low, and ensure that all gases inside the energy storage device 100 can be discharged smoothly, thereby avoiding safety accidents caused by poor exhaust, and further improving the safety performance of the energy storage device 100.

[0073] See also Figure 6 , Fig.13 and Fig.14 , Fig.13 yes Figure 8 The schematic diagram of the exploded structure of the pole unit 40 in the end cover assembly 130 is shown. Fig.14 yes Fig.13 The structure diagram of the upper plastic 41 in the pole unit 40 is shown.

[0074] In this embodiment, two pole units 40 are respectively penetrated in two assembly holes 213. Among them, one pole unit 40 is a positive pole unit, and is electrically connected to the positive pole tab of the electrode assembly 120, and the other pole unit 40 is a negative pole unit, and is electrically connected to the negative pole tab of the electrode assembly 120. In this embodiment, the structure of each component in each pole unit 40, the assembly relationship between the components, and the assembly relationship between the components and the lower plastic 10 and the cover plate 20 are the same or similar. The structure of each component in a pole unit 40, the assembly relationship between the components, and the assembly relationship between the components and the lower plastic 10 and the cover plate 20 will be described below.

[0075] Specifically, each pole unit 40 includes an upper plastic 41, a pole 42, a seal 43 and an adapter 44. The upper plastic 41 is inserted into an assembly hole 213 of the cover plate 20. Specifically, the upper plastic 41 includes a plastic body 411 and an extension 412. The extension 412 is fixedly connected to one end of the plastic body 411. The plastic body 411 is mounted on the first surface 211 of the main body 21, and the extension 412 is inserted into the assembly hole 213.

[0076] The upper plastic 41 is also provided with a matching groove 413 and a mounting hole 414. Specifically, the opening of the matching groove 413 is located on the surface of the plastic body 411 away from the main body 21. The matching groove 413 is recessed from the surface of the plastic body 411 away from the main body 21 toward the main body 21. The mounting hole 414 penetrates the upper plastic 41 along the thickness direction of the upper plastic 41. Specifically, the opening of the mounting hole 414 is located on the bottom surface of the upper plastic 41. The mounting hole 414 is recessed from the bottom surface of the upper plastic 41 toward the matching groove 413, and penetrates the groove bottom wall surface of the matching groove 413 to communicate with the matching groove 413. Among them, the mounting hole 414 is coaxial with the assembly hole 213 and is connected.

[0077] In this embodiment, the pole 42 is inserted through the mounting hole 414 of the upper plastic 41 and a through hole 103 of the lower plastic 10. The pole 42 includes a flange portion 421 and a column portion 422. The flange portion 421 is fixedly connected to one side of the column portion 422. Specifically, the column portion 422 is inserted through the mounting hole 414 of the upper plastic 41, and the flange portion 421 is located in the matching groove 413 of the upper plastic 41. Among them, the plastic body of the upper plastic 41 is located between the flange portion 421 and the main body 21 of the cover plate 20, and the extension portion 412 of the upper plastic 41 is located between the circumferential surface of the column portion 422 and the hole wall surface of the assembly hole 213, so as to avoid the end cover assembly 130 from being short-circuited due to direct contact between the pole 42 and the cover plate 20. The pole 42 is used to be electrically connected to the electrical connecting sheet 200, so that the energy storage device 100 is electrically connected to the electrical connecting sheet 200.

[0078] The adapter 44 is installed on the inner side of the lower plastic 10, and is sleeved on the column 422 of the pole 42, and is spaced apart from the cover plate 20. Specifically, one end of the adapter 44 is electrically connected to the column 422 of the pole 42, and the other end is electrically connected to the pole ear of the electrode assembly 120. Exemplarily, the adapter 44 can be electrically connected to the column 422 of the pole 42 and / or the pole ear of the electrode assembly 120 by welding.

[0079] The seal 43 is located in a through hole 103 of the lower plastic 10, and is sleeved on the extension 412 of the upper plastic 41, and is clamped between the cover plate 20 and the adapter 44. It is understood that the seal 43 can ensure the assembly stability between the upper plastic 41, the lower plastic 10, and the cover plate 20. It is understood that the seal 43 can not only ensure the assembly stability between the adapter 44, the cover plate 20, and the lower plastic 10, but also prevent the adapter 44 from directly contacting the cover plate 20 for electrical conduction, thereby achieving insulation between the adapter 44 and the cover plate 20.

[0080] Please refer to Figure 2 and Figure 3 . When the above-mentioned end cover assembly 130 is assembled, the end cover assembly 130 is assembled with structural parts such as the shell 110 and the electrode assembly 120 to obtain an energy storage device 100. Then arrange multiple energy storage devices 100 along the first direction X. Then install the wiring harness isolation plate 300 to one side of the height direction of the energy storage device 100. Specifically, the wiring harness isolation plate 300 is installed on the side of the boss portion 22 of the cover plate 20 away from the main body 21. At this time, the opening of the mounting groove 310 of the wiring harness isolation plate 300 faces the side of the wiring harness isolation plate 300 away from the boss portion 22. The avoidance hole 311 of the wiring harness isolation plate 300 avoids the pole 42 of the energy storage device 100, so that the pole 42 is exposed relative to the bottom wall of the groove of the mounting groove 310 of the wiring harness isolation plate 300, so as to facilitate the subsequent electrical connection between the electrical connection plate 200 and the pole 42, thereby realizing electrical connection between the electrical connection plate 200 and the energy storage device 100. Then the electrical connection piece 200 is installed in the installation groove 310. Specifically, the first portion 210 of the electrical connection piece 200 is electrically connected to the flange portion 421 of the pole 42, and the second portion 220 of the electrical connection piece 200 is spaced apart from the bottom wall of the installation groove 310. At this time, along the height direction of the energy storage module 1000, the surface of the second portion 220 away from the flange portion 421 of the pole 42 is flush with the surface of the boss portion 22 of the wiring harness isolation plate 300 away from the cover plate 20.

[0081] It can be understood that by making the surface of the second part 220 of the electrical connecting piece 200 facing away from the pole 42 flush with the surface of the wiring harness isolation plate 300 facing away from the boss portion 22, the flatness of the top surface of the energy storage module 1000 can be ensured to be good, and the boss portion 22 set on the cover plate 20 can be avoided from causing obstacles to the installation of the wiring harness isolation plate 300 and the collection harness 400 on the energy storage device 100, thereby ensuring the connection reliability between the collection harness 400 and the electrical connecting piece 200 and helping to improve the overall space utilization of the energy storage module 1000.

[0082] The present application also provides an electric device, which includes the energy storage module 1000, and the energy storage module 1000 supplies power to the electric device, wherein the electric device may be a new energy vehicle, a power storage station, a server, or other equipment that requires electricity.

[0083] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application; in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An energy storage device, characterized in that: The invention comprises a shell, an electrode assembly and a cover plate, wherein the shell has an opening and a receiving cavity, the opening is connected to the receiving cavity, the electrode assembly is received in the receiving cavity, the cover plate is installed on the shell and closes the opening, the cover plate comprises a main body and a boss portion, the main body comprises a first surface and a second surface, along the thickness direction of the main body, the first surface and the second surface are arranged opposite to each other, the boss portion is fixedly connected to the main body and protrudes relative to the first surface, the boss portion comprises a first surface away from the electrode assembly and a second surface arranged opposite to the first surface, the first surface and the second surface are both located on the side of the first surface away from the second surface, the boss portion is provided with an explosion-proof hole, the explosion-proof hole passes through the first surface and the second surface along the thickness direction of the boss portion, the second surface is convexly provided with at least one first sub-protrusion, at least one The first sub-protrusions are spaced apart from the explosion-proof hole. Along the height direction of the energy storage device, a surface of at least one of the first sub-protrusions facing the electrode assembly is located on the side of the second surface away from the first surface, and at least one of the first sub-protrusions is arranged opposite to the electrode assembly. The surface of the first sub-protrusion facing the electrode assembly is also provided with at least one second sub-protrusion. Along the height direction of the energy storage device, at least one of the second sub-protrusions is arranged opposite to the electrode assembly. The cover plate is also provided with at least one recess, and the opening of at least one recess faces the side of the cover plate away from the electrode assembly. Along the thickness direction of the cover plate, at least one recess is arranged opposite to the first sub-protrusion and the second sub-protrusion. Along the thickness direction of the cover plate, the distance d2 between the bottom wall of at least one recess and the first surface is within 0.1 The recess comprises a first groove and a second groove, the opening of the first groove faces the side of the cover plate away from the electrode assembly, and along the thickness direction of the cover plate, the first groove is arranged opposite to the first sub-protrusion, the first groove comprises a first groove bottom wall, the opening of the second groove faces the first groove bottom wall, and the second groove is connected to the first groove, along the thickness direction of the cover plate, the second groove is arranged opposite to the second sub-protrusion, the second groove comprises a second groove bottom wall, and the second groove bottom wall is the groove bottom wall of the recess.

2. The energy storage device according to claim 1, characterized in that: There are a plurality of the first sub-protrusions, and along the length direction of the cover plate, the plurality of the first sub-protrusions are respectively arranged on two opposite sides of the explosion-proof hole and are spaced apart from each other.

3. The energy storage device according to claim 2, characterized in that: There are a plurality of the second sub-protrusions, and each of the second sub-protrusions is protruding from a surface of the first sub-protrusion facing the electrode assembly.

4. The energy storage device according to any one of claims 1 to 3, characterized in that: Along the thickness direction of the cover plate, a ratio of a distance d1 between a surface of at least one of the first sub-protrusions facing the electrode assembly and the first surface to the thickness of the cover plate is between 2 and 3.

5. The energy storage device according to claim 1, characterized in that: Along the thickness direction of the cover plate, the ratio of the distance d3 between the first groove bottom wall and the first surface to the thickness of the cover plate is less than or equal to 2, and the ratio of the distance d4 between the second groove bottom wall and the first groove bottom wall to the thickness of the cover plate is less than or equal to 2.

6. The energy storage device according to claim 1, characterized in that: The boss portion is further provided with a liquid injection hole, which penetrates the first surface and the second surface along the thickness direction of the boss portion and is spaced apart from the explosion-proof hole and the first sub-protrusion.

7. The energy storage device according to claim 1, characterized in that: The energy storage device also includes an explosion-proof valve and a lower plastic. The explosion-proof valve is installed on the boss portion and connected to the explosion-proof hole. The lower plastic is installed on the side of the second surface away from the first surface. The lower plastic is provided with an explosion-proof fence and at least one avoidance groove. The explosion-proof fence penetrates the lower plastic along the thickness direction of the lower plastic. Along the height direction of the energy storage device, the explosion-proof fence is arranged opposite to and connected to the explosion-proof hole. The opening of at least one avoidance groove is arranged toward the cover plate. At least one avoidance groove is spaced apart from the explosion-proof fence. At least one avoidance groove avoids the first sub-protrusion and the second sub-protrusion.

8. The energy storage device according to claim 7, characterized in that: The lower plastic is also provided with reinforcing ribs, and the reinforcing ribs are arranged on a side away from the explosion-proof fence and away from the explosion-proof hole.

9. An energy storage module, characterized in that: It comprises an electrical connection piece, a wiring harness isolation plate and an energy storage device as described in any one of claims 1 to 8, wherein the electrical connection piece and the wiring harness isolation plate are both located on one side in the height direction of the energy storage device, wherein the electrical connection piece is electrically connected to the energy storage device.

10. The energy storage module according to claim 9, characterized in that: The main body is also provided with an assembly hole, and the assembly hole penetrates the main body along the thickness direction of the main body; The energy storage device further includes a pole, and the pole is passed through the assembly hole; The harness isolating plate is installed on the side of the boss away from the main body, the harness isolating plate is provided with a mounting groove, the opening of the mounting groove is toward the side of the harness isolating plate away from the boss, the bottom wall of the mounting groove is provided with an avoidance hole, along the thickness direction of the bottom wall of the mounting groove, the avoidance hole penetrates the bottom wall of the mounting groove, and the avoidance hole avoids the pole; The electrical connecting piece is installed in the installation groove and is electrically connected to the pole. The electrical connecting piece includes two first parts and a second part. Along the length direction of the electrical connecting piece, the two first parts are arranged at intervals, the first part is electrically connected to the pole, and the second part is fixedly connected between the two first parts and protrudes relative to the surface of the first part away from the pole. Along the height direction of the energy storage module, the surface of the second part away from the pole is flush with the surface of the wiring harness isolation plate away from the boss portion.

11. An electrical device, characterized in that: It comprises the energy storage module as claimed in claim 9 or 10, wherein the energy storage module supplies power to the electrical equipment.

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