End cap assembly, energy storage device, and electric appliance

Abstract

The application provides an end cover assembly, an energy storage device and an electric equipment, guarantees good exhaust performance of the energy storage device, and improves safety performance of the energy storage device. The end cover assembly comprises an end cover, an explosion-proof valve and a lower insulating piece. The end cover is provided with an explosion-proof hole. The explosion-proof valve is installed on the end cover and covers the explosion-proof hole. In the thickness direction of the end cover, the lower insulating piece is located on one side of the end cover and has a first surface and a second surface arranged oppositely. The lower insulating piece is provided with a first boss and a protrusion. The first boss and the protrusion are arranged on the second surface and arranged in the width direction of the lower insulating piece. A first boss surface of the first boss is used for pressing an electric core assembly of the energy storage device. The protrusion is arranged correspondingly with the explosion-proof valve and has a protrusion surface. The lower insulating piece is further provided with a first air hole. The first air hole is arranged on the protrusion. In the thickness direction of the lower insulating piece, the distance between the protrusion surface and the first surface is smaller than the distance between the protrusion surface and the first boss surface.

Description

Technical Field

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

[0002] With the increasingly widespread application of energy storage devices, their safety performance has become a major concern. In the event of thermal runaway, an energy storage device will rapidly generate gas inside. The lower insulation component may come into contact with the explosion-proof valve, damaging it. The gas cannot quickly reach the explosion-proof valve and open it, preventing the timely release of gas from the energy storage device. This can easily lead to an explosion, posing a significant safety hazard and reducing the device's safety and reliability. Utility Model Content

[0003] This application provides an end cap assembly, an energy storage device, and an electrical device to ensure good exhaust performance of the energy storage device and improve its safety performance.

[0004] This application provides an end cap assembly for use in an energy storage device, including an end cap, an explosion-proof valve, and a lower insulating component. The end cap is provided with an explosion-proof hole that penetrates the end cap along its thickness direction. The explosion-proof valve is installed on the end cap and covers the explosion-proof hole; Along the thickness direction of the end cap, the lower insulating member is located on one side of the end cap and has a first surface and a second surface, the first surface facing the end cap and the second surface being disposed opposite to the first surface; The lower insulating member is provided with a first boss and a protrusion. The first boss and the protrusion are both provided on the second surface and are arranged along the width direction of the lower insulating member. The first boss has a first boss surface, which is the surface of the first boss facing away from the second surface, and is used to press against the cell assembly of the energy storage device. The protrusion is disposed opposite to the explosion-proof valve and has a protruding surface. The protruding surface is the surface of the protrusion that faces away from the second surface. Along the thickness direction of the lower insulating member, the distance between the protruding surface and the first surface is D1, and the distance between the protruding surface and the first boss surface is D2, where D1 < D2. The lower insulating member is further provided with a first vent hole, which is located on the protrusion and penetrates the protrusion along the thickness direction of the lower insulating member. The lower insulating member is further provided with a first groove, the opening of the first groove is located on the first surface, the first groove is correspondingly provided with the protrusion, and has a first groove bottom wall surface, the first groove bottom wall surface is opposite to the opening of the first groove, and is opposite to the surface of the protrusion. Along the thickness direction of the lower insulating component, the distance between the bottom wall of the first groove and the explosion-proof valve is D3, where 1mm≤D3≤2mm.

[0005] The first vent hole is multiple, and each first vent hole is arranged around the center of the protrusion. Along the direction from the center of the protrusion to the edge, the multiple first vent holes are arranged at intervals. The multiple first vent holes include edge vent holes. The edge vent holes are the first vent holes with the largest distance from the center of the protrusion among the multiple first vent holes. The edge vent holes include edge hole walls that are away from the center of the protrusion. When the end cap assembly is used in the energy storage device, along the width direction of the end cap assembly, the electrode is located on the side of the edge hole wall facing away from the center of the protrusion and is spaced apart from the edge hole wall, and the electrode has an inner surface facing the edge hole wall. Along the width direction of the lower insulator, the minimum distance between the edge hole wall and the inner surface of the tab in the cell assembly is D4, where 2mm≤D4≤9mm.

[0006] The explosion-proof valve has a first peripheral side that is flush with the wall of the edge hole, or the first peripheral side is located on the side of the wall of the edge hole near the center of the protrusion.

[0007] The lower insulating member is further provided with a side vent hole. The side vent hole is located on the protrusion along the length of the lower insulating member. The side vent hole is located on the side of the first vent hole away from the center of the protrusion and is spaced apart from the first vent hole, and penetrates the protrusion.

[0008] The minimum distance between the wall surface of the side vent and the inner surface of the tab is D5, where D5 ≥ D4.

[0009] There are two first bosses, which are located on opposite sides of the protrusion along the width direction of the lower insulating member.

[0010] The lower insulating member is further provided with a second protrusion, which is located on the second surface. The second protrusion is located on one side of the first protrusion and on one side of the first vent hole, and is used to press against the battery cell assembly.

[0011] The second protrusion has a first side and a second side, the first side being the surface of the second protrusion facing the first vent hole, and the second side being disposed opposite to the first side. The lower insulating member is provided with a second groove, a second vent hole, a third vent hole and a fourth vent hole. The opening of the second groove is located on the first surface. The second groove is correspondingly arranged with the second boss. The second groove has a first groove side wall and a second groove side wall. The first groove side wall is arranged opposite to the first side. Along the length direction of the lower insulating member, the second groove side wall is arranged opposite to the first groove side wall and opposite to the second side. The second vent hole penetrates the first side surface and the first groove side wall. The second vent hole has a first hole wall and a second hole wall. Along the width direction of the lower insulating member, the first hole wall and the second hole wall are arranged opposite to each other. Both the third vent and the fourth vent penetrate the second side surface and the second groove side wall, and are spaced apart along the width direction of the lower insulating member. The third vent has a third hole wall surface away from the fourth vent, and the projection of the third hole wall surface on the first side surface overlaps with the first hole wall surface, or the third hole wall surface is located on the side of the first hole wall surface facing the second hole wall surface. The fourth vent has a fourth hole wall surface away from the third vent, and the projection of the fourth hole wall surface on the first side surface overlaps with the second hole wall surface, or the fourth hole wall surface is located on the side of the second hole wall surface facing the first hole wall surface.

[0012] The second protrusion further has a second protrusion surface, which is the surface of the second protrusion facing away from the second surface, and is connected between the first side and the second side, and is used to press against the battery cell assembly. The second groove also has a second groove bottom wall surface, which is connected between the first groove side wall surface and the second groove side wall surface, and is disposed opposite to the surface of the second boss. The lower insulating component is also provided with a fifth vent hole, which penetrates the surface of the second boss and the bottom wall of the second groove.

[0013] The battery cell assembly includes two cores, which are arranged along the width of the lower insulation member and form a corner area, which is opposite to the fifth vent hole.

[0014] There are two of each of the second protrusion and the second groove. Along the length of the lower insulating member, the two second protrusions are located on opposite sides of the first vent hole and are spaced apart from the first vent hole. Each second groove corresponds to one second protrusion.

[0015] This application also provides an energy storage device, which includes a housing, a battery cell assembly, and an end cap assembly as described above. The housing has a receiving cavity and an opening. The receiving cavity is located inside the housing and contains an electrolyte. The opening is located on the top side of the receiving cavity and communicates with the receiving cavity. The battery cell assembly is housed in the receiving cavity. The end cap assembly is mounted on the housing and closes the opening, and is electrically connected to the battery cell assembly. The first boss abuts against the battery cell assembly.

[0016] This application also provides an electrical device, including the energy storage device as described above, the energy storage device being used to supply power to the electrical device.

[0017] This application provides a protrusion on the lower insulating component, and makes the distance between the protrusion surface and the first surface less than the distance between the protrusion surface and the first boss surface. This ensures that the lower insulating component does not contact the explosion-proof valve in the event of thermal runaway of the energy storage device. It also prevents the protrusion from damaging the explosion-proof valve due to the floating of the battery cell assembly and the rebound of the diaphragm. This ensures the venting of the end cover assembly and helps to improve the venting performance and safety performance of the energy storage device. Attached Figure Description

[0018] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0019] Figure 1 This is a schematic diagram of the structure of an energy storage system according to an embodiment of this application; Figure 2 This is a schematic diagram of the energy storage device structure provided in this application; Figure 3 yes Figure 2 The diagram shows the exploded structure of the energy storage device. Figure 4 yes Figure 3 A schematic diagram of the assembly structure of the housing, Mylar membrane, and battery cell assembly in the energy storage device shown. Figure 5 yes Figure 3 A schematic diagram of the planar structure of the energy storage device shown after being cut along point AA. Figure 6 yes Figure 3 An exploded view of the end cap assembly in the energy storage device shown. Figure 7 yes Figure 3 The diagram shows a cross-sectional view of the end cap assembly after it has been cut open along point BB. Figure 8 yes Figure 7 The diagram below shows the structure of the insulating component; Figure 9 yes Figure 8The diagram shows a cross-section of the lower insulating component along point CC. Figure 10 yes Figure 5 A schematic diagram of the lower insulating component in the end cap assembly shown from another angle; Figure 11 yes Figure 8 The diagram shows a cross-section of the lower insulating component along point DD. Figure 12 yes Figure 3 The diagram shows the assembly of the end cap assembly and the cell assembly in the energy storage device from another angle.

[0020] Reference numerals: 1. Energy storage system; 2. High-voltage cable; 3. First energy conversion device; 4. Second energy conversion device; 5. Energy storage device; 1000. Housing; 2000. Cell assembly; 3000. End cap assembly; 4000. Mylar membrane; 5000. Reception cavity; 2001. Opening; 2002. Core; 3100. Corner area T; 3200. Electrode; 3201. Inner surface; 100. Lower insulation component; 200. End cap; 300. Explosion-proof valve; 400. Protective plate; 500. Electrode post; 600. Connecting piece. 700 upper insulating component, 800 sealing ring, 101 first surface, 102 second surface, 103 second peripheral side, 110 second boss, 120 first boss, 130 protrusion, 111 second boss surface, 112 first boss side, 113 first side, 114 second side, H-melt zone, 121 first boss surface, 122 second boss side, 123 third side, 124 fourth side, 130b venting zone, 131 protruding surface, 134 protruding side 32. Second groove 140, First groove 150, Third groove 160, First vent 170, Side vent 178, First pole hole 180, First injection hole 190, Second vent 10, Third vent 20a, Fourth vent 20b, Fifth vent 31, Sixth vent 35, Seventh vent 40, Second groove bottom wall 141, First groove side wall 142, Second groove side wall 143, Third groove side wall 144, First groove bottom wall 151 First wall surface 152, second wall surface 153, third tank bottom wall surface 161, fourth tank side wall surface 162, fifth tank side wall surface 163, sixth tank side wall surface 164, edge vent hole 175, edge hole wall surface 176, first hole wall surface 11, second hole wall surface 12, third hole wall surface 21, fourth hole wall surface 22, reinforcing rib Q, explosion-proof hole 210, second pole hole 220, second injection hole 230, third surface 301, fourth surface 302, first peripheral side surface 303. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve energy efficiency, it is necessary to store one form of energy in the same way or by converting it into another, and then release it in a specific energy form for future applications. Currently, the main way to generate green electricity is to develop green energy sources such as photovoltaics and wind power to replace fossil fuels. Currently, the generation of green electricity generally relies on solar, wind, and hydropower. However, wind and solar power are generally characterized by strong intermittency and large fluctuations, which can cause grid instability, insufficient power during peak demand periods, and excessive power during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar curtailment." Solving these problems requires energy storage. This involves converting electrical energy into other forms of energy through physical or chemical means and storing it. When needed, this energy can be converted back into electrical energy and released. Simply put, energy storage is like a large "power bank," storing electrical energy when solar and wind power are abundant and releasing the stored electricity when needed.

[0023] Taking electrochemical energy storage as an example, this solution provides an energy storage device 1000, which is applied to an energy storage system 1. The energy storage device 1000 is equipped with a set of chemical batteries, which mainly use the chemical elements in the batteries as energy storage medium. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. Simply put, the electrical energy generated by wind and solar energy is stored in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electrical energy is released for use, or transferred to places with a shortage of electricity for use.

[0024] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, and consumption-side energy storage. The corresponding types of energy storage devices include: (1) Large-scale energy storage power stations applied to wind power and photovoltaic power stations can help renewable energy power generation meet grid connection requirements and improve the utilization rate of renewable energy. As a high-quality active / reactive power regulation power source on the power supply side, energy storage power stations can achieve load matching of power in time and space, enhance the absorption capacity of renewable energy, reduce instantaneous power changes, reduce the impact on the power grid, improve the absorption of new energy power generation, and are of great significance in power grid system backup, alleviating peak load power supply pressure and peak regulation and frequency regulation. (2) Energy storage containers applied on the grid side mainly function as peak shaving, frequency regulation and relief of grid congestion. In terms of peak shaving, they can realize peak shaving and valley filling of electricity load, that is, charging the energy storage battery when the electricity load is low and releasing the stored electricity during the peak electricity load period, thereby achieving a balance between power production and consumption. (3) Small energy storage cabinets applied to the electricity consumption side mainly function as self-consumption of electricity, peak-valley price arbitrage, capacity cost management, and improvement of power supply reliability. Depending on the application scenario, electricity consumption side energy storage can be divided into industrial and commercial energy storage cabinets, household energy storage devices, energy storage charging piles, etc., which are generally used in conjunction with distributed photovoltaics. Industrial and commercial users can use energy storage for peak-valley price arbitrage and capacity cost management. In the electricity market implementing peak-valley pricing, by charging the energy storage system when the electricity price is low and discharging the energy storage system when the electricity price is high, peak-valley price arbitrage can be achieved, reducing electricity costs. In addition, industrial enterprises subject to two-part tariffs can use energy storage systems to store energy during off-peak hours and discharge during peak loads, thereby reducing peak power and the maximum demand declared, achieving the goal of reducing capacity costs. Household photovoltaics with energy storage can improve the level of self-consumption of electricity. Due to high electricity prices and poor power supply stability, the demand for household photovoltaic installations is driven. Given that photovoltaic power generation occurs during the day, while user load is generally higher at night, configuring energy storage can better utilize photovoltaic power, improve self-consumption levels, and reduce electricity costs. Furthermore, energy storage is needed in areas such as communication base stations and data centers for backup power.

[0025] In some embodiments, see Figure 1 , Figure 1 This is a schematic diagram of the structure of an energy storage system 1 according to an embodiment of this application, and this application Figure 1 The embodiments are illustrated using a shared energy storage scenario on the generation / distribution side as an example. The energy storage device 1000 of this application is not limited to its generation / distribution side energy storage scenario.

[0026] This application provides an energy storage system 1, which includes: a high-voltage cable 2, a first power conversion device 3, a second power conversion device 4, and an energy storage device 1000 provided in this application. In some embodiments of the power generation scenario, the second power conversion device 4 can be a wind power conversion device. Since the electricity generated by wind power conversion is volatile, random, and intermittent, the unstable electricity output by the wind power conversion device can be stored in the energy storage device 1000 through grid connection. The energy storage device 1000 is connected to the high-voltage cable 2 and outputs smooth electricity to supply the power consumption side of the distribution network, realizing peak shaving and frequency regulation, and stable grid operation; or, the wind power conversion device... Always connected to high-voltage cable 2, under normal power generation conditions, the power output of the wind power conversion device is supplied to the power consumption side of the distribution network through the high-voltage cable. When the current power load is low and the wind power conversion device generates excess power, the excess power is first stored in energy storage device 1000 to reduce wind and solar curtailment rates and improve the problem of new energy power generation consumption. When the power load is high, the power grid issues an instruction to transmit the power stored in energy storage device 1000 together with high-voltage cable 2 in grid-connected mode to supply power to the power consumption side, providing multiple services such as peak shaving, frequency regulation, and backup for power grid operation, giving full play to the peak shaving role of the power grid, promoting peak shaving and valley filling of the power grid, and alleviating the power supply pressure of the power grid.

[0027] In some embodiments on the distribution network side, the first power conversion device 3 can be a photovoltaic power conversion device. The energy storage device 1000 is connected to the high-voltage cable 2 and installed downstream of the high-voltage cable 2 between the user load and the user load. The power output by the photovoltaic power conversion device is stored in the energy storage device 1000, which can respond in a timely manner to act as a backup power source when the power grid / distribution network fails. Alternatively, it can provide power supply support to alleviate line congestion when the high-voltage cable 2 transmission line is blocked, and to delay the economic pressure caused by the expansion of the power grid / distribution capacity when the power grid is planned to be expanded.

[0028] Optionally, the first power conversion device may include, but is not limited to, a wind power conversion device, and the second power conversion device may include, but is not limited to, a photovoltaic power conversion device. The first power conversion device 3 and the second power conversion device 4 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy, and mechanical energy into electrical energy.

[0029] Optionally, the energy storage device 1000 may include, but is not limited to, energy storage applications such as energy storage power stations, hydropower / thermal / wind power generation systems, solar power generation systems, mobile power systems, smart home systems, or temporary power supply systems, and may also be applied in multiple fields such as data centers, military equipment, aerospace, charging piles, and electric vehicles.

[0030] Please see Figure 2 , Figure 2This is a schematic diagram of the energy storage device 1000 provided in this application.

[0031] This application provides an energy storage device 1000, which may include, but is not limited to, a battery cell, a battery module, a battery pack, or a battery system. Optionally, when the energy storage device 1000 is a battery cell, it may be, but is not limited to, at least one of cylindrical, prismatic, prismatic, or other shaped batteries. Optionally, the battery cell may be a rechargeable battery, which refers to a battery cell that can be recharged after discharge to activate its active materials and continue to be used. The battery cell may be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application does not specifically limit this. The actual application form of the energy storage device provided in this application may be, but is not limited to, the listed products, and may also be other application forms. This application does not strictly limit the application form of the energy storage device 1000. This application uses a prismatic battery as an example for illustration.

[0032] Please refer to the following: Figures 3 to 5 , Figure 3 yes Figure 2 The exploded structural diagram of the energy storage device 1000 shown is as follows. Figure 4 yes Figure 3 The diagram shows the assembly structure of the energy storage device 1000, comprising the housing 2000, the Mylar membrane 5000, and the battery cell assembly 3000. Figure 5 yes Figure 3 A schematic diagram of the planar structure of the energy storage device 1000 after being cut along point AA.

[0033] The energy storage device 1000 includes a housing 2000, a cell assembly 3000, an end cap assembly 4000, and a Mylar membrane 5000. The housing 2000 has a receiving cavity 2001 and an opening 2002. The receiving cavity 2001 is located inside the housing 2000 and contains electrolyte. The opening 2002 is located on the top side of the receiving cavity 2001 and communicates with it. The housing 2000 may be made of aluminum; for example, the housing 2000 may be an aluminum shell. The cell assembly 3000 is housed in the receiving cavity 2001. The cell assembly 3000 can be immersed in the electrolyte. The cell assembly 3000 includes two cores 3100. The two cores 3100 are arranged along the width direction of the lower insulator 100 and form two corner areas T. Along the length of the energy storage device 1000, two corner areas T are located at opposite ends of the cell assembly 3000. Each core 3100 includes two tabs 3200. The two tabs 3200 are spaced apart and arranged along the length of the energy storage device 1000. One tab 3200 is a positive tab, and the other tab 3200 is a negative tab. Along the width of the energy storage device 1000, the positive tabs of the two cores 3100 are arranged opposite each other, and the negative tabs of the two cores 3100 are arranged opposite each other. Each tab 3200 has an inner surface 3201 facing the tab 3200 of the other core 3100. In this embodiment, the two inner surfaces 3201 of the positive tabs of the two cores 3100 are arranged opposite each other. The two inner surfaces 3201 of the negative tabs of the two cores 3100 are arranged opposite each other. The end cap assembly 4000 is mounted on the housing 2000, closes the opening 2002, and is electrically connected to the cell assembly 3000. The Mylar membrane 5000 is housed in the receiving cavity 2001, located between the housing 2000 and the cell assembly 3000, and wraps around the cell assembly 3000; it is also connected to the end cap assembly 4000. The Mylar membrane 5000 can be connected to the end cap assembly 4000 by heat fusion to isolate the housing 2000 and the cell assembly 3000.

[0034] Please see Figure 6 and Figure 7 , Figure 6 yes Figure 3 The diagram shows an exploded view of the end cap assembly 4000 in the energy storage device 1000. Figure 7 yes Figure 3 The diagram shows a cross-sectional view of the end cap assembly 4000 after it has been cut along point BB.

[0035] In this embodiment, the end cap assembly 4000 includes a lower insulating member 100, an end cap 200, an explosion-proof valve 300, a protective plate 400, a pole 500, a connecting piece 600, an upper insulating member 700, and a sealing ring 800. The lower insulating member 100 is thermally fused to the Mylar membrane 5000. Along the thickness direction of the end cap assembly 4000, the end cap 200 is mounted on one side of the lower insulating member 100. The explosion-proof valve 300 and the protective plate 400 are both mounted on the end cap 200. The pole 500 passes through the end cap 200 and the lower insulating member 100. There are two poles 500, arranged at intervals along the length direction of the end cap assembly 4000. One pole 500 serves as the positive pole, and the other pole 500 serves as the negative pole. A connecting piece 600 is located on the side of the lower insulator 100 opposite to the end cap 200 and on the side of the terminal 500, connected to the terminal 500 and electrically connected to the tab 3200 of the cell assembly 3000. There are two connecting pieces 600. The two connecting pieces 600 are spaced apart along the length of the end cap assembly 4000. One connecting piece 600 serves as a positive connecting piece, connected to the positive terminal and electrically connected to the positive tabs of both cell assemblies 3000. The other connecting piece 600 serves as a negative connecting piece, connected to the negative terminal and electrically connected to the negative tabs of both cell assemblies 3000. An upper insulator 700 is installed between the terminal 500 and the end cap 200. There are two upper insulators 700, each installed between one terminal 500 and the end cap 200. One upper insulating component 700 serves as the positive electrode insulating component and is installed between the positive electrode post and the end cap 200. Another upper insulating component 700 serves as the negative electrode insulating component and is installed between the negative electrode post and the end cap 200. A sealing ring 800 is fitted onto the upper insulating component 700 and clamped between the end cap 200 and the electrode post 500. There are two sealing rings 800; each sealing ring 800 is fitted onto one upper insulating component 700 and clamped between the end cap 200 and one electrode post 500. One sealing ring 800 serves as the positive electrode sealing ring, fitted onto the positive electrode insulating component and clamped between the end cap 200 and the positive electrode post. The other sealing ring 800 serves as the negative electrode sealing ring, fitted onto the negative electrode insulating component and clamped between the end cap 200 and the negative electrode post.

[0036] Please continue reading. Figures 7 to 9 , Figure 8 yes Figure 7 The diagram below shows the structure of the lower insulating component 100. Figure 9 yes Figure 8 The diagram shows a cross-section of the lower insulating component 100 along the CC direction.

[0037] The lower insulating member 100 includes a first surface 101, a second surface 102, and two second peripheral side surfaces 103. The first surface 101 faces the end cap 200. Along the thickness direction of the lower insulating member 100, the second surface 102 and the first surface 101 are disposed opposite to each other. Along the width direction of the lower insulating member 100, the two second peripheral side surfaces 103 are disposed opposite to each other and connected between the first surface 101 and the second surface 102.

[0038] The lower insulating member 100 is provided with a second boss 110, a first boss 120, and a protrusion 130. The second boss 110, the first boss 120, and the protrusion 130 are all located on the second surface 102 and protrude from the second surface 102 in a direction away from the first surface 101. Along the length of the lower insulating member 100, the second boss 110 is located at the end of the lower insulating member 100. The second boss 110 includes a second boss surface 111 and a first boss side surface 112. The second boss surface 111 is the surface of the second boss 110 facing away from the second surface 102 and is used to abut against the battery cell assembly 3000. For example, the distance between the second boss surface 111 and the second surface 102 is 5.5 mm, that is, the height of the second boss 110 is 5.5 mm. The first boss side surface 112 is disposed around the second boss surface 111 and connects between the second boss surface 111 and the second surface 102. The first protrusion side 112 includes a first side 113 and a second side 114. The first side 113 is the surface of the second protrusion 110 facing the first vent hole 170. Along the length of the lower insulating member 100, the second side 114 is disposed opposite to the first side 113 and is respectively connected to the opposite ends of the second protrusion surface 111. The second protrusion surface 111 connects the first side 113 and the second side 114. For example, the second protrusion 110 is elongated, and the length direction of the second protrusion 110 is parallel to the width direction of the lower insulating member 100. In this embodiment, there are two second protrusions 110, which are spaced apart. Along the length of the lower insulating member 100, the two second protrusions 110 are respectively located at opposite ends of the lower insulating member 100.

[0039] The first boss 120 and the protrusion 130 are arranged along the width direction of the lower insulating member 100. Specifically, along the length direction of the lower insulating member 100, the first boss 120 is located in the middle of the lower insulating member 100 and is spaced apart from the second boss 110. The first boss 120 is located between the two second bosses 110 and is spaced apart from both second bosses 110, and is used to press against the cell assembly 3000. The first boss 120 has a first boss surface 121 and a second boss side surface 122. The first boss surface 121 is the surface of the first boss 120 facing away from the second surface 102 and is used to abut against the cell assembly 3000. For example, the distance between the first boss surface 121 and the second surface 102 is 5.5 mm, that is, the height of the first boss 120 is 5.5 mm. The second boss side surface 122 is disposed around the first boss surface 121 and connects between the first boss surface 121 and the second surface 102. The second boss side 122 includes a third side 123 and a fourth side 124. Along the width direction of the lower insulating member 100, the fourth side 124 and the third side 123 are arranged opposite to each other and connected to the second peripheral side 103. Exemplarily, the first boss 120 is square. There are two first bosses 120, spaced apart. Along the width direction of the lower insulating member 100, the two first bosses 120 are located at opposite ends of the lower insulating member 100.

[0040] The second protrusion 110 and the first protrusion 120 press against the cell assembly 3000, which can fix the cell assembly 3000 and prevent the tabs 3200 from tearing or the core 3100 from loosening due to shaking of the cell assembly 3000. This reduces the impact of the cell assembly 3000 moving along the thickness direction of the lower insulation member 100 inside the energy storage device 1000, improves the stability of the internal structure of the energy storage device 1000, and enhances the safety performance and reliability of the energy storage device 1000.

[0041] Along the length of the lower insulating member 100, the protrusion 130 is located in the middle of the lower insulating member 100, between and connected to the two first protrusions 120, and is also opposite to the explosion-proof valve 300. Specifically, the protrusion 130 has a venting area 130b. The venting area 130b is arranged around the center of the protrusion 130. The protrusion 130 has a protruding surface 131 and a protruding side surface 132. The protruding surface 131 is the surface of the protrusion 130 that faces away from the second surface 102, and is connected between the third side surface 123 of the two first protrusions 120. Along the thickness direction of the lower insulating member 100, the distance between the protruding surface 131 and the first protrusion surface 121 is D2, and the distance between the first surface 101 and the protruding surface 131 is D1, D1 < D2, ensuring that the venting area 130b is close to the first surface 101 and away from the cell assembly 3000. The raised side 132 is disposed around the raised surface 131 and is connected between the raised surface 131 and the second surface 102.

[0042] The lower insulating member has a heat-fusion zone H. The heat-fusion zone H is located on the second side surface 114. Along the width direction of the lower insulating member 100, the heat-fusion zone H is located at the middle of the second side surface 114. The lower insulating member 100 can be heat-fused to the Mylar film 5000 in the heat-fusion zone H.

[0043] Please refer to the following: Figure 9 and Figure 10 , Figure 10 yes Figure 5 The diagram shows the structure of the lower insulating member 100 in the end cap assembly 4000 from another angle.

[0044] The lower insulating member 100 is further provided with a second groove 140, a first groove 150, a third groove 160, a first vent hole 170, a first pole hole 180, a first injection hole 190, a second vent hole 10, a third vent hole 20a, a fourth vent hole 20b, a fifth vent hole 31, a sixth vent hole 35, and a seventh vent hole 40. Along the length of the lower insulating member 100, the second groove 140 is located at the end of the lower insulating member 100 and is correspondingly disposed to the second boss 110. It should be noted that the second groove 140 corresponding to the second boss 110 means that the projection of the second groove 140 on the second boss 110 will cover a portion of the second boss 110. Specifically, the opening of the second groove 140 is located on the first surface 101. The second groove 140 is recessed from the first surface 101 towards the second boss 110 and is spaced apart from both the second peripheral side surface 103 and the first boss side surface 112.

[0045] The second groove 140 includes a second groove bottom wall 141, a first groove side wall 142, a second groove side wall 143, and two third groove side walls 144. The second groove bottom wall 141 is positioned opposite the opening of the second groove 140 and is located between the second boss surface 111 and the second surface 102, and is positioned opposite to the second boss surface 111. Along the length of the lower insulating member 100, the first groove side wall 142 and the second groove side wall 143 are positioned opposite each other and are respectively connected to the opposite ends of the second groove bottom wall 141, and are both connected between the second groove bottom wall 141 and the first surface 101. The first groove side wall 142 is positioned opposite to the first side surface 113. The second groove side wall 143 is located on the side of the first groove side wall 142 away from the first boss 120 and is positioned opposite to the second side surface 114. The two third groove side walls 144 are both connected between the first groove side wall 142 and the second groove side wall 143. Along the width direction of the lower insulating member 100, two third groove sidewalls 144 are disposed opposite to each other. There are two second grooves 140, spaced apart. Along the length direction of the lower insulating member 100, the two second grooves 140 are located on opposite sides of the first boss 120 and correspond to the two second bosses 110 respectively. For example, the second grooves 140 are elongated, and their length direction is parallel to the width direction of the lower insulating member 100.

[0046] Along the length of the lower insulating member 100, a first groove 150 is located between two second grooves 140, and is spaced apart from both second grooves 140, and is correspondingly positioned to correspond with a protrusion 130. It should be noted that the first groove 150 corresponding to the protrusion 130 means that the projection of the first groove 150 onto the protrusion 130 partially covers the protrusion 130. Along the width of the lower insulating member 100, the first groove 150 is located between two first bosses 120. The opening of the first groove 150 is located on the first surface 101. The first groove 150 is recessed from the first surface 101 towards the second surface 102. The first groove 150 has a first groove bottom wall surface 151, a first wall surface 152, and a second wall surface 153. The first groove bottom wall surface 151 is located between the protruding surface 131 and the first surface 101, and is positioned opposite to the protruding surface 131. When the lower insulating member 100 is used in the end cap assembly 4000 of the energy storage device 1000, the distance between the first tank bottom wall surface 151 and the explosion-proof valve 300 of the end cap assembly 4000 along the thickness direction of the lower insulating member 100 is D3, where 1mm≤D3≤2mm. The first wall surface 152 and the second wall surface 153 are both connected between the first tank bottom wall surface 151 and the first surface 101. Along the length direction of the lower insulating member 100, the second wall surface 153 and the first wall surface 152 are arranged opposite to each other.

[0047] Along the length of the lower insulating member 100, the third groove 160 is located between the two second grooves 140 and is spaced apart from the second grooves 140, and is correspondingly arranged with the first boss 120. It should be noted that the correspondence between the third groove 160 and the first boss 120 means that the projection of the third groove 160 onto the first boss 120 partially covers the first boss 120. Along the width of the lower insulating member 100, the third groove 160 is located on one side of the first groove 150 and communicates with the first groove 150. Specifically, the opening of the third groove 160 is located on the first surface 101. The third groove 160 is recessed from the first surface 101 towards the second surface 102. The third groove 160 has a third groove bottom wall surface 161, a fourth groove side wall surface 162, a fifth groove side wall surface 163, and a sixth groove side wall surface 164. The third groove bottom wall surface 161 is located on the side of the second surface 102 opposite to the first surface 101. The fourth slot sidewall 162 and the fifth slot sidewall 163 are both connected between the third slot bottom wall 161 and the first surface 101. The fourth slot sidewall 162 is connected to the first wall 152. Along the length of the lower insulating member 100, the fifth slot sidewall 163 is opposite to the fourth slot sidewall 162 and connected to the second wall 153. The sixth slot sidewall 164 is connected between the fourth slot sidewall 162 and the fifth slot sidewall 163, and is also connected between the third slot bottom wall 161 and the first slot bottom wall 151.

[0048] Please refer to the following: Figure 5 and Figure 10 The first vent 170, the side vent 178, the first pole hole 180, and the first injection hole 190 all penetrate the first surface 101 and the second surface 102. The first vent 170 is located in the venting area 130b of the protrusion 130, and is spaced apart from the first boss 120, and is located between the two first bosses 120. The first vent 170 penetrates the protrusion 130 along the thickness direction of the lower insulating member 100, that is, the first vent 170 penetrates the protrusion surface 131 and the first groove bottom wall surface 151. It should be noted that, along the width direction of the lower insulating member 100, the first vent 170 is located between the tabs 3200 of the two cores 3100, ensuring that the area of ​​the inner surface 3201 away from the first vent 170 (excluding the first boss 120) is free of holes. When the tabs 3200 are assembled with the end cap assembly 4000, abnormal overlap between the tabs 3200 and the end cap 200 due to misalignment is prevented. In addition, the distance between the raised surface 131 and the first boss surface 121 is greater than the distance between the first surface 101 and the raised surface 131, which keeps the vent area 130b away from the cell assembly 3000. This prevents the vent area 130b from blocking the first vent 170 due to the floating of the cell assembly 3000 and the rebound of the diaphragm, which is beneficial to improving the venting performance and safety performance of the energy storage device 1000.

[0049] In this embodiment, there are multiple first vent holes 170. These multiple first vent holes 170 are spaced apart and of varying sizes. Each first vent hole 170 is arranged around the center of the protrusion 130. Along the direction from the center of the protrusion 130 to the edge, the multiple first vent holes are arranged sequentially at intervals. For example, the multiple first vent holes 170 are arranged in a mesh-like mosquito coil shape. The multiple first vent holes 170 include edge vent holes 175. The edge vent hole 175 is the first vent hole 170 with the largest distance from the center of the protrusion 130 among the multiple first vent holes 170. The edge vent hole 175 includes an edge hole wall surface 176 facing away from the center of the protrusion 130.

[0050] Along the width direction of the lower insulator 100, the edge hole wall 176 is located between the two tabs 3200 and between the inner surfaces 3201 of the two tabs 3200. Along the width direction of the end cap assembly 4000, the tabs 3200 are located on the side of the edge hole wall opposite to the center of the protrusion 130 and are spaced apart from the edge hole wall 176. The inner surface 3201 is the surface of the tab 3200 facing the edge hole wall 176. The minimum distance between the edge hole wall 176 and the inner surface 3201 of the tab 3200 is D4, where 2mm ≤ D4 ≤ 9mm. This ensures that the first vent hole 170 has sufficient cross-sectional area to guarantee good venting performance of the lower insulator 100, while also considering a safety margin for the assembly of the tabs 3200 and the end cap assembly 4000, ensuring that the tabs 3200 will not abnormally overlap with the end cap 200 through the first vent hole 170.

[0051] It should be noted that at the moment the explosion-proof valve 300 is opened, the connection between the multiple first vent holes 170 at the protrusion 130 will rupture under the impact of air pressure and be rushed out to the outside of the energy storage device 1000 by the airflow. At this time, the exhaust channel of the lower insulating component 100 corresponding to the explosion-proof valve 300 is fully opened to ensure that the energy storage device 1000 can be depressurized smoothly.

[0052] A side vent 178 is provided on the protrusion 130, located on the side of the first vent 170 away from the center of the protrusion 130, and extends through the protrusion 130 along its thickness direction. The minimum distance between the wall surface of the side vent 178 and the inner surface 3201 of the tab 3200 in the cell assembly 3000 is D5, where D5 ≥ D4. This increases the ventilation channel of the lower insulator 100 while ensuring that the tab 3200 will not abnormally overlap with the end cap 200 through the side vent 178. Multiple side vents 178 are provided. Along the length of the lower insulator 100, multiple side vents 178 are located on opposite sides of the first vent 170.

[0053] The first electrode post hole 180 is located between the first vent hole 170 and the second protrusion 110. There are two first electrode post holes 180. One first electrode post hole 180 is located between the first vent hole 170 and the second protrusion 110. The other first electrode post hole 180 is located between the first vent hole 170 and the other second protrusion 110. The first injection hole 190 is located between one first electrode post hole 180 and the first vent hole 170, and is spaced apart from both. In this embodiment, the first injection hole 190 is located on the side of the first wall surface 152 away from the second wall surface 153, and is spaced apart from the first wall surface 152.

[0054] Please continue reading. Figure 9 and Figure 11 , Figure 11 yes Figure 8 The diagram shows a cross-section of the lower insulating component 100 along point DD.

[0055] The second vent 10, the third vent 20a, the fourth vent 20b, the fifth vent 31, and the sixth vent 35 are all provided on the second boss 110. The second vent 10 is provided on the groove sidewall of each second groove 140 facing the first vent 170, and penetrates the groove sidewall along the thickness direction of the groove sidewall of the second groove 140. Specifically, the second vent 10 penetrates the first sidewall 113 and the first groove sidewall 142, and communicates with the second groove 140. Along the width direction of the lower insulating member 100, the second vent 10 and the second peripheral sidewall 103 are spaced apart. In this embodiment, the second vent 10 also penetrates the second boss surface 111 and the second groove bottom wall 141 to increase the exhaust channel and improve the exhaust speed of the lower insulating member 100. The second vent 10 has a first hole wall surface 11 and a second hole wall surface 12. Along the width of the lower insulating member 100, the first hole wall surface 11 and the second hole wall surface 12 are arranged opposite to each other and are spaced apart from the second peripheral side surface 103. For example, the second vent hole 10 is a rectangular hole. It should be noted that since the first side surface 113 is not thermally fused to the Mylar membrane 5000, the distance between the first hole wall surface 11 and the second hole wall surface 12 of the second vent hole 10 can be sufficiently large and less than the length of the second boss 110, to ensure that the second vent hole 10 has a large cross-sectional area for airflow, which is beneficial for timely guiding gas to the explosion-proof valve 300.

[0056] The third vent 20a and the fourth vent 20b are provided on the groove sidewall of each second groove 140 away from the first vent 170, and penetrate the groove sidewall along the thickness direction of the groove sidewall of the second groove 140. Specifically, the third vent 20a and the fourth vent 20b both penetrate the second groove sidewall surface 143 and the second side surface 114, and are spaced apart along the width direction of the lower insulating member 100, and are respectively located on opposite sides of the heat fusion zone H. The third vent 20a and the fourth vent 20b are both connected to the second groove 140, and are spaced apart from the heat fusion zone H, and are used for heat fusion connection with the Mylar membrane 5000. It should be noted that the spaced arrangement of the third vent 20a and the fourth vent 20b from the heat fusion zone H can prevent the third vent 20a and the fourth vent 20b from affecting the heat fusion connection between the heat fusion zone H of the lower insulating member 100 and the Mylar membrane 5000, thereby improving the assembly stability of the energy storage device 1000. In addition, the third vent 20a and the fourth vent 20b both penetrate the bottom wall surface 141 of the second groove and the surface 111 of the second boss to increase the exhaust channel and increase the exhaust speed of the lower insulating member 100.

[0057] The third vent 20a has a third hole wall 21 that is away from the fourth vent 20b. The projection of the third hole wall 21 onto the first side surface 113 overlaps with the first hole wall 11, or the third hole wall 21 is located on the side of the first hole wall 11 facing the second hole wall 12. The fourth vent 20b has a fourth hole wall 22 that is away from the third vent 20a. Along the width direction of the lower insulating member 100, the fourth hole wall 22 and the third hole wall 21 are arranged opposite each other and face the same direction as the second hole wall 12. The projection of the fourth hole wall 22 onto the first side surface 113 overlaps with the second hole wall 12, or the fourth hole wall 22 is located on the side of the second hole wall 12 facing the first hole wall 11. This configuration ensures that gas on both sides of the battery cell assembly 3000 can smoothly pass through the second vent 10 from the third vent 20a and the fourth vent 20b, and then reach the position of the first vent 170, guaranteeing the effectiveness of venting of the lower insulating member 100 and improving the venting performance and safety performance of the energy storage device. For example, the third vent 20a and the fourth vent 20b are rectangular holes. Along the width direction of the lower insulating member 100, the length of both the third vent 20a and the fourth vent 20b is 15.5 mm, and along the length direction of the lower insulating member 100, the depth of both the third vent 20a and the fourth vent 20b is 3 mm.

[0058] Please refer to the following: Figure 12 , Figure 12 yes Figure 3 This is a schematic diagram of the assembly of the end cap assembly 4000 and the cell assembly 3000 in the energy storage device 1000 from another angle.

[0059] The fifth vent 31 and the sixth vent 35 are both located on the bottom wall of each second groove 140 and penetrate the bottom wall of the second groove 140 along the thickness direction of the lower insulating member 100. Specifically, the fifth vent 31 and the sixth vent 35 both penetrate the bottom wall surface 141 of the second groove and the surface 111 of the second boss, and both communicate with the second groove 140. The fifth vent 31 is positioned opposite to the corner area T. It should be noted that, due to the heat-fusion connection between the Mylar membrane 5000 and the second side surface 114 of the lower insulating member 100, the Mylar membrane 5000 adheres to the second side surface 114, blocking the airflow from the side of the battery cell assembly 3000 into the third vent 20a and the fourth vent 20b, thus limiting the exhaust effect of the lower insulating member 100. The fifth vent 31 eliminates the problem that gas cannot be exhausted through the third vent 20a and fourth vent 20b after the Mylar membrane 5000 is thermally fused with the second side 114. This ensures that airflow from both sides of the cell assembly 3000 can quickly enter the fifth vent 31, and then flow through the second vent 10 to the first vent 170, improving the exhaust speed of the lower insulation component 100. This ensures good exhaust performance of the energy storage device 1000 and improves its safety performance. For example, the fifth vent 31 is a rectangular hole.

[0060] The sixth vent 35 is located on one side of the fifth vent 31 and is spaced apart from the fifth vent 31. There are multiple sixth vents 35. Along the length of the second boss 110, multiple sixth vents 35 are located on opposite sides of the fifth vent 31 and are spaced apart from the fifth vent 31. The arrangement of the sixth vents 35 increases the exhaust channel of the lower insulating member 100, allowing gas inside the energy storage device 1000 to enter the second groove 140 through the sixth vent 35, and then reach the explosion-proof valve 300 through the second vent 10, ensuring good exhaust performance of the energy storage device 1000 and improving the safety performance of the energy storage device 1000.

[0061] In this embodiment, by providing a second vent 10, a third vent 20a, a fourth vent 20b, a fifth vent 31, and a sixth vent 35, in the event of thermal runaway of the energy storage device 1000, the gas generated inside can quickly enter the second groove 140 through the third vent 20a, the fourth vent 20b, the fifth vent 31, or the sixth vent 35, and then flow through the second vent 10 to the area below the explosion-proof valve 300. This facilitates the timely opening and pressure relief of the explosion-proof valve 300, ensuring good venting performance of the energy storage device 1000 and improving its safety performance. Furthermore, the fifth vent 31 and the sixth vent 35 also serve to guide the electrolyte flow. Specifically, during the manufacturing and transportation of the energy storage device 1000, the electrolyte in the containment cavity will enter the lower insulating component 100. The electrolyte located in the lower insulating component 100 can be returned to the containment cavity through the fifth vent 31 and the sixth vent 35 to ensure that the electrolyte plays its role in the containment cavity.

[0062] Please continue reading. Figure 10 and Figure 11 A seventh vent 40 is provided at each of the first protrusions 120 and penetrates the first protrusion 120 along the thickness direction of the lower insulating member 100. Specifically, the seventh vent 40 penetrates the bottom wall of the third groove and the surface 121 of the first protrusion, and communicates with the third groove 160. The setting of the seventh vent 40 increases the exhaust channel of the lower insulating member 100, allowing the gas inside the energy storage device 1000 to directly enter the third groove 160 through the seventh vent 40, and then enter the gap between the lower insulating member 100 and the end cap 200, thereby reaching the explosion-proof valve 300, ensuring good exhaust performance of the energy storage device 1000 and improving the safety performance of the energy storage device 1000. It should be noted that since the first protrusion 120 has a certain height, it can limit the electrode 3200 during the assembly process. Therefore, misaligned electrode 3200 will not pass through the seventh vent 40 and abnormally overlap with the end cap 200.

[0063] The lower insulating member 100 is also provided with reinforcing ribs Q. The reinforcing ribs Q are disposed on the bottom wall surface 141 of the second groove and connected between the side wall surface 142 of the first groove and the side wall surface 143 of the second groove. In this embodiment, the length direction of the reinforcing ribs Q is parallel to the length direction of the lower insulating member 100. Multiple reinforcing ribs Q are provided. Multiple reinforcing ribs Q are arranged at intervals along the width direction of the lower insulating member 100. For example, multiple reinforcing ribs Q are arranged in parallel. By providing multiple reinforcing ribs Q, the structural strength of the second boss 110 can be enhanced, ensuring that the second boss 110 can better resist and restrict the battery cell assembly 3000, thereby improving the stability of the internal structure of the energy storage device 1000, reducing safety risks, and improving the safety performance and reliability of the energy storage device 1000. For example, each second groove 140 has five reinforcing ribs Q, and the wall thickness of each reinforcing rib Q is 1 mm.

[0064] Please continue reading. Figure 7 The end cap 200 can be a smooth aluminum sheet made of aluminum. The end cap 200 is located on the side of the first surface 101 facing away from the second surface 102. It should be noted that the distance D2 between the raised surface 131 and the first boss surface 121 is greater than the distance D1 between the first surface 101 and the raised surface 131. That is, the distance between the surface of the end cap 200 facing the lower insulating member 100 and the raised surface is less than the distance between the raised surface 131 and the first boss surface 121. This ensures that the venting area 130b is close to the end cap 200, which is beneficial for increasing the gas discharge from the lower insulating member 100 to the end cap 200, and then to the explosion-proof valve 300, thereby improving the exhaust performance and safety performance of the energy storage device 1000.

[0065] The end cap 200 is provided with an explosion-proof hole 210, a second pole hole 220, and a second injection hole 230. The explosion-proof hole 210, the second pole hole 220, and the second injection hole 230 all penetrate the end cap 200 along its thickness direction. Along the length of the end cap 200, the explosion-proof hole 210 is located in the middle of the end cap 200 and is positioned opposite to the first vent hole 170. It should be noted that the opposite positioning of the explosion-proof hole 210 and the first vent hole 170 means that the orthogonal projection of the explosion-proof hole 210 onto the lower insulating member 100 will at least partially cover the first vent hole 170.

[0066] The second electrode post hole 220 is spaced apart from the explosion-proof hole 210 and communicates with the first electrode post hole 180 to allow the electrode post 500 to pass through. There are two second electrode post holes 220. Along the length of the end cap 200, the two second electrode post holes 220 are located on either side of the explosion-proof hole 210 and communicate with the two first electrode post holes 180 respectively. Specifically, one second electrode post hole 220 communicates with one first electrode post hole 180 for the positive electrode post to pass through. The other second electrode post hole 220 communicates with the other first electrode post hole 180 for the negative electrode post to pass through. The second injection hole 230 is located between the explosion-proof hole 210 and one of the second electrode post holes 220, spaced apart from both, and communicates with the first injection hole 190.

[0067] The explosion-proof valve 300 covers the explosion-proof hole 210. The explosion-proof valve 300 has a third surface 301, a fourth surface 302, and a first peripheral side surface 303. The third surface 301 is the surface of the explosion-proof valve 300 facing the lower insulating member 100. The distance between the first tank bottom wall 151 and the explosion-proof valve 300 is greater than or equal to 1 mm and less than or equal to 2 mm. That is, the distance between the third surface 301 and the first tank bottom wall 151 is greater than or equal to 1 mm and less than or equal to 2 mm, which allows for a certain distance between the lower insulating member 100 and the explosion-proof valve 300. This prevents the protrusion 130 from damaging the explosion-proof valve 300 due to the floating of the battery cell assembly 3000 and the diaphragm rebounding and contacting the explosion-proof valve 300. This enhances the structural stability of the end cap assembly 4000 and thus improves the safety performance of the energy storage device 1000. Along the thickness direction of the explosion-proof valve 300, the fourth surface 302 is arranged opposite to the third surface 301. The first peripheral side 303 is connected between the third surface 301 and the fourth surface 302. The first peripheral side 303 is welded to the wall of the explosion-proof hole 210. The first peripheral side 303 is located on the side of the edge hole wall 176 near the center of the protrusion 130, or the first peripheral side 303 is flush with the edge hole wall 176. With this configuration, during the manufacturing process of the end cap assembly 4000, the appearance of the explosion-proof valve 300 can be easily observed through the edge vent hole 175, facilitating the inspection and verification of the explosion-proof valve 300's appearance.

[0068] The protective plate 400 protects the explosion-proof valve 300. Along the thickness direction of the end cap assembly 4000, each pole post 500 passes through a second pole post hole 220 and a first pole post hole 180. Each connecting piece is located on the side of the second surface 102 away from the first surface 101, between a first boss 120 and a second boss 110, and is electrically connected to a pole post. Each upper insulating member 700 is arranged around a pole post 500 and passes through a second pole post hole 220 and a first pole post hole 180. Each sealing ring 800 is fitted onto a pole post and onto an upper insulating member 700, passes through a first pole post hole 180, and is also clamped between the end cap 200 and a pole post 500. This not only seals the gap between the end cap 200 and the pole post 500, ensuring good airtightness of the end cap assembly 4000, but also insulates the end cap 200 from the pole post 500.

[0069] Please continue reading. Figure 3 The Mylar membrane 5000 is thermally fused to the second side 114 of the two second protrusions 110 to isolate the housing 2000 and the cell assembly 3000 and to protect the cell assembly 3000, thereby improving the safety performance of the energy storage device 1000.

[0070] The energy storage device 1000 provided in this embodiment, by providing a protrusion 130 on the lower insulating member 100 and making the distance between the protrusion surface 131 and the first surface 101 smaller than the distance between the protrusion surface 131 and the first boss surface 121, ensures that the lower insulating member 100 does not contact the explosion-proof valve 300 in the event of thermal runaway of the energy storage device 1000. This avoids damage to the explosion-proof valve 300 caused by the protrusion 130 abutting against it due to the floating of the battery cell assembly 3000 and the rebound of the diaphragm, thus ensuring the venting of the end cap assembly 4000 and improving the venting performance and safety performance of the energy storage device 1000. Furthermore, by providing a second vent 10, a third vent 20a, and a fourth vent 20b on the lower insulating member 100, and by making the projection of the third hole wall 21 on the first side 113 overlap with the first hole wall 11, and the projection of the fourth hole wall 22 on the first side 113 overlap with the second hole wall 12, it is ensured that the gas on both sides of the cell assembly 3000 can smoothly pass through the second vent 10 from the third vent 20a and the fourth vent 20b, and then reach the position of the first vent 170, thus ensuring the effectiveness of the venting of the lower insulating member 100, which is conducive to further improving the venting performance and safety performance of the energy storage device 1000.

[0071] This application also provides an electrical device, such as an energy storage cabinet or a new energy vehicle. This electrical device includes the energy storage device 1000 described in the above embodiments, and the energy storage device 1000 supplies power to the electrical device. Since the specific structure and technical effects of the energy storage device 1000 have already been described in detail above, they will not be repeated here. The electrical device provided in this embodiment, by incorporating the aforementioned energy storage device 1000, improves the exhaust performance and operational safety and reliability of the electrical device.

[0072] The above descriptions are merely optional embodiments of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of this application and are not intended to limit the patent scope of this application. At the same time, for those skilled in the art, equivalent structural transformations made based on the concept of this application using the specification and drawings of this application, or direct / indirect applications in other related technical fields, are all included within the patent protection scope of this application.

Claims

1. An end cap assembly for use in an energy storage device, characterized in that, It includes an end cap, an explosion-proof valve, and a lower insulating component. The end cap is provided with an explosion-proof hole that penetrates the end cap along its thickness direction. The explosion-proof valve is installed on the end cap and covers the explosion-proof hole; Along the thickness direction of the end cap, the lower insulating member is located on one side of the end cap and has a first surface and a second surface, the first surface facing the end cap and the second surface being disposed opposite to the first surface; The lower insulating member is provided with a first boss and a protrusion. The first boss and the protrusion are both provided on the second surface and are arranged along the width direction of the lower insulating member. The first boss has a first boss surface, which is the surface of the first boss facing away from the second surface, and is used to press against the cell assembly of the energy storage device. The protrusion is disposed opposite to the explosion-proof valve and has a protruding surface. The protruding surface is the surface of the protrusion that faces away from the second surface. Along the thickness direction of the lower insulating member, the distance between the protruding surface and the first surface is D1, and the distance between the protruding surface and the first boss surface is D2, where D1 < D2. The lower insulating member is further provided with a first vent hole, which is located on the protrusion and extends through the protrusion along the thickness direction of the lower insulating member.

2. The end cap assembly according to claim 1, characterized in that, The lower insulating member is further provided with a first groove, the opening of the first groove is located on the first surface, the first groove is correspondingly provided with the protrusion, and has a first groove bottom wall surface, the first groove bottom wall surface is opposite to the opening of the first groove, and is opposite to the surface of the protrusion. Along the thickness direction of the lower insulating component, the distance between the bottom wall of the first groove and the explosion-proof valve is D3, where 1mm≤D3≤2mm.

3. The end cap assembly according to claim 1 or 2, characterized in that, There are multiple first vent holes, each of which is arranged around the center of the protrusion. Along the direction from the center of the protrusion to the edge, the multiple first vent holes are arranged at intervals. The multiple first vent holes include edge vent holes. The edge vent holes are the first vent holes with the largest distance from the center of the protrusion among the multiple first vent holes. The edge vent holes include edge hole walls that are away from the center of the protrusion. When the end cap assembly is used in the energy storage device, along the width direction of the end cap assembly, the electrode is located on the side of the edge hole wall facing away from the center of the protrusion and is spaced apart from the edge hole wall, and the electrode has an inner surface facing the edge hole wall. Along the width direction of the lower insulator, the minimum distance between the edge hole wall and the inner surface of the tab in the cell assembly is D4, where 2mm≤D4≤9mm.

4. The end cap assembly according to claim 3, characterized in that, The explosion-proof valve has a first peripheral side that is flush with the wall of the edge hole, or the first peripheral side is located on the side of the wall of the edge hole near the center of the protrusion.

5. The end cap assembly according to claim 3, characterized in that, The lower insulating member is also provided with a side vent hole. The side vent hole is located on the protrusion along the length direction of the lower insulating member. The side vent hole is located on the side of the first vent hole away from the center of the protrusion and is spaced apart from the first vent hole, and penetrates the protrusion.

6. The end cap assembly according to claim 5, characterized in that, The minimum distance between the wall surface of the side vent and the inner surface of the tab is D5, where D5 ≥ D4.

7. The end cap assembly according to claim 1 or 2, characterized in that, There are two first bosses, located on opposite sides of the protrusion along the width direction of the lower insulating member.

8. The end cap assembly according to claim 1 or 2, characterized in that, The lower insulating member is further provided with a second protrusion, which is located on the second surface. The second protrusion is located on one side of the first protrusion and on one side of the first vent hole, and is used to press against the battery cell assembly.

9. The end cap assembly according to claim 8, characterized in that, The second protrusion has a first side and a second side, the first side being the surface of the second protrusion facing the first vent hole, and the second side being disposed opposite to the first side; The lower insulating member is provided with a second groove, a second vent hole, a third vent hole and a fourth vent hole. The opening of the second groove is located on the first surface. The second groove is correspondingly arranged with the second boss. The second groove has a first groove side wall and a second groove side wall. The first groove side wall is arranged opposite to the first side. Along the length direction of the lower insulating member, the second groove side wall is arranged opposite to the first groove side wall and opposite to the second side. The second vent hole penetrates the first side surface and the first groove side wall. The second vent hole has a first hole wall and a second hole wall. Along the width direction of the lower insulating member, the first hole wall and the second hole wall are arranged opposite to each other. Both the third vent and the fourth vent penetrate the second side surface and the second groove side wall, and are spaced apart along the width direction of the lower insulating member. The third vent has a third hole wall surface away from the fourth vent, and the projection of the third hole wall surface on the first side surface overlaps with the first hole wall surface, or the third hole wall surface is located on the side of the first hole wall surface facing the second hole wall surface. The fourth vent has a fourth hole wall surface away from the third vent, and the projection of the fourth hole wall surface on the first side surface overlaps with the second hole wall surface, or the fourth hole wall surface is located on the side of the second hole wall surface facing the first hole wall surface.

10. The end cap assembly according to claim 8, characterized in that, The second protrusion also has a second protrusion surface, which is the surface of the second protrusion facing away from the second surface, and is connected between the first side and the second side, and is used to press against the cell assembly; The second groove also has a second groove bottom wall surface, which is connected between the first groove side wall surface and the second groove side wall surface, and is disposed opposite to the surface of the second boss. The lower insulating component is also provided with a fifth vent hole, which penetrates the surface of the second boss and the bottom wall of the second groove.

11. The end cap assembly according to claim 10, characterized in that, The battery cell assembly includes two cores, which are arranged along the width of the lower insulator and form a corner area, which is opposite to the fifth vent hole.

12. The end cap assembly according to claim 8, characterized in that, There are two of each of the second protrusion and the second groove. Along the length of the lower insulating member, the two second protrusions are located on opposite sides of the first vent hole and are spaced apart from the first vent hole. Each second groove corresponds to one of the second protrusions.

13. An energy storage device, characterized in that, The energy storage device includes a housing, a cell assembly, and an end cap assembly as described in any one of claims 1 to 12. The housing has a receiving cavity and an opening. The receiving cavity is located inside the housing and contains an electrolyte. The opening is located on the top side of the receiving cavity and communicates with the receiving cavity. The cell assembly is housed in the receiving cavity. The end cap assembly is mounted on the housing and closes the opening, and is electrically connected to the cell assembly. The first boss abuts against the cell assembly.

14. An electrical appliance, characterized in that, Includes the energy storage device as described in claim 13, wherein the energy storage device is used to supply power to the electrical equipment.

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