End cover assembly, energy storage device and electric equipment

Abstract

The invention provides an end cover assembly, an energy storage device and electric equipment. The end cover assembly comprises an end cover, an anti-explosion valve, a lower insulating part and a support. The end cover is provided with an anti-explosion hole, and the anti-explosion hole penetrates through the end cover in the thickness direction of the end cover. The anti-explosion valve is installed on the end cover and covers the anti-explosion hole. The upper insulating part and the lower insulating part are located on one side of the end cover in the thickness direction of the end cover. The lower insulating part is provided with a first surface and a second surface, the first surface faces the end cover, and the second surface is opposite to the first surface. The lower insulating part is provided with a through hole, and the through hole penetrates through the first surface and the second surface and is opposite to the anti-explosion valve. The support and the lower insulating part are located on the same side of the end cover and penetrate through the through hole. The melting point of the support is larger than that of the lower insulator. The support comprises a shielding part, the shielding part is located on the side, away from the first surface, of the second surface, the shielding part and the second surface are arranged in a spaced mode, and the shielding part is opposite to the through hole. And the orthographic projection of the anti-explosion valve on the bracket covers at least part of the shielding part.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to an end cover assembly, an energy storage device and an electric equipment. BACKGROUND

[0002] A secondary battery, also known as a rechargeable battery or a storage battery, refers to a battery that can be activated by charging after discharging to continue to be used. The recyclable feature of the secondary battery makes it gradually become the main power source of electric equipment. With the increasing demand for secondary batteries, people's requirements for their performance are also getting higher and higher, especially for the reliability of secondary batteries. When the existing secondary battery overheats, the explosion-proof valve opens first, and the gas mixed with flammable particles rises and sprays out from the position of the explosion-proof valve, which is extremely easy to be ignited and cause a fire at the position of the explosion-proof valve, resulting in safety hazards in the use of the secondary battery. SUMMARY

[0003] The present application provides an end cover assembly, an energy storage device and an electric equipment, which can avoid the secondary battery from catching fire when it overheats, reduce the safety hazards of the secondary battery, and improve the reliability of the secondary battery.

[0004] In a first aspect, the present application provides an end cover assembly for use in an energy storage device. The end cover assembly includes an end cover, an explosion-proof valve, a lower insulating piece and a bracket. The end cover is provided with an explosion-proof hole, and the explosion-proof hole penetrates the end cover along the thickness direction of the end cover. The explosion-proof valve is installed on the end cover and covers the explosion-proof hole. The lower insulating piece is located on one side of the end cover along the thickness direction of the end cover. The lower insulating piece has a first surface and a second surface, the first surface faces the end cover, and the second surface is arranged opposite to the first surface. The lower insulating piece is provided with a through hole, the through hole penetrates the first surface and the second surface, and is arranged opposite to the explosion-proof valve. The bracket is located on the same side of the end cover as the lower insulating piece, and is arranged through the through hole. The melting point of the bracket is greater than the melting point of the lower insulating piece. The bracket includes a shielding portion, the shielding portion is located on the side of the second surface away from the first surface, and is arranged spaced apart from the second surface in the thickness direction of the lower insulating piece and opposite to the through hole, and the orthographic projection of the explosion-proof valve on the bracket covers at least part of the shielding portion.

[0005] Since the shielding portion is arranged opposite to the through hole, when the energy storage device has thermal runaway, the high-temperature gas cannot be directly ejected from the through hole through the explosion-proof hole along the thickness direction of the end cover assembly, and can only enter the through hole from the gap between the shielding portion and the lower insulating member and then be ejected through the explosion-proof hole. The shielding portion can block the molten aluminum beads, thereby preventing the molten aluminum beads from being ignited and burning after being directly ejected from the through hole through the explosion-proof hole and coming into contact with carbonized debris, thereby preventing the energy storage device from catching fire when thermal runaway occurs, reducing the safety risks of the energy storage device, and improving the reliability of the energy storage device.

[0006] The through hole has a first hole wall surface and a second hole wall surface. Along the length direction of the lower insulating member, the first hole wall surface and the second hole wall surface are spaced apart and arranged opposite to each other.

[0007] The shielding portion has a first side surface and a second side surface, the first side surface faces the plane where the first hole wall surface is located, and the second side surface is arranged opposite to the first side surface and faces the plane where the second hole wall surface is located.

[0008] The bracket also includes a first baffle portion and a second baffle portion, the first baffle portion is fixedly connected to the first side surface, extends from the shielding portion toward the lower insulating member, and is arranged opposite to the first hole wall surface, the second baffle portion is fixedly connected to the second side surface, extends from the shielding portion toward the lower insulating member, and is arranged opposite to the second hole wall surface, and the first baffle portion and the second baffle portion are staggered along the width direction of the lower insulating member.

[0009] It should be noted that, along the width direction of the lower insulating member, the staggered arrangement of the first baffle portion and the second baffle portion means that the orthographic projection of the first baffle portion on the projection plane and the orthographic projection of the second baffle portion on the projection plane at least partially do not overlap, wherein the projection plane is parallel to the width direction of the lower insulating member and the thickness direction of the lower insulating member.

[0010] When thermal runaway occurs in the energy storage device, high-temperature gas can only enter the through-hole from the portion of the gap between the shielding portion and the lower insulating member that is not blocked by the first baffle portion and the second baffle portion, and then be ejected through the explosion-proof hole. Since the first baffle portion and the second baffle portion are staggered, along the length direction of the end cover assembly, the two airflows entering the through-hole from the left and right sides of the through-hole will not collide and cause energy loss. The two airflows can be ejected farther from the explosion-proof hole, which can avoid the accumulation of substances such as carbonized debris, molten aluminum beads and electrolyte at the explosion-proof hole. Moreover, since the densities of substances such as carbonized debris, molten aluminum beads and electrolyte are different, the ejection distances of substances with different densities will also be different. Therefore, substances with different densities will not accumulate together, which can further reduce the probability of fire, avoid fire when thermal runaway occurs in the energy storage device, reduce the safety hazards of the energy storage device, and improve the reliability of the energy storage device.

[0011] Among them, along the length direction of the lower insulating member, the first baffle portion and the second baffle portion are completely staggered to reduce the shielding of the high-temperature gas by the first baffle portion and the second baffle portion, ensuring that when thermal runaway occurs in the energy storage device, most of the high-temperature gas can be ejected from the explosion-proof hole, thereby ensuring the reliability of the energy storage device.

[0012] It should be noted that, along the width direction of the lower insulating member, the first baffle portion and the second baffle portion are completely staggered, which means that the orthographic projection of the first baffle portion on the projection plane and the orthographic projection of the second baffle portion on the projection plane do not overlap at all, wherein the projection plane is parallel to the width direction of the lower insulating member and the thickness direction of the lower insulating member.

[0013] In which, along the width direction of the lower insulating member, the sum of the length of the first baffle portion and the length of the second baffle portion is less than or equal to the length of the shielding portion to reduce the shielding of the high-temperature gas by the first baffle portion and the second baffle portion, ensuring that when thermal runaway occurs in the energy storage device, most of the high-temperature gas can be ejected from the explosion-proof hole, thereby ensuring the reliability of the energy storage device.

[0014] The first baffle portion and the second baffle portion are both located on the side of the first surface facing the second surface, so as to avoid the first baffle portion and the second baffle portion protruding relative to the first surface and interfering with the end cover, thereby ensuring the structural stability of the end cover assembly.

[0015] The bracket is provided with a first notch and a second notch, the first notch and the second notch both pass through the bracket along the thickness direction of the shielding portion, and are respectively located on opposite sides of the bracket along the length direction of the lower insulating member and are spaced apart from each other;

[0016] There are two first notches, which are respectively located on opposite sides of the first baffle portion and adjacent to the first baffle portion. At least one first notch passes through the first side surface, and the first baffle portion is folded relative to the shielding plate. Wherein, the first notch is adjacent to the first baffle portion, which means that the first notch is adjacent to and connected to the first baffle portion, that is, there is no distance between the first notch and the first baffle portion.

[0017] There are two second notches, one located on opposite sides of the second baffle portion and adjacent to the second baffle portion. At least one second notch extends through the second side surface, formed by folding the second baffle portion relative to the shielding portion. The second notch being adjacent to the second baffle portion means that the second notch is adjacent to and connected to the second baffle portion, i.e., there is no distance between the second notch and the second baffle portion.

[0018] The design of the first notch and the second notch not only facilitates the formation of the first baffle portion and the second baffle portion, but also avoids the generation of sharp points at the connection positions of the first baffle portion and the second baffle portion with the shielding portion when the first baffle portion and the second baffle portion are folded to form the first baffle portion and the second baffle portion, thereby avoiding the sharp points from scratching operators or other components, and also avoiding the generation of easily falling metal chips that affect the reliability of the energy storage device.

[0019] In which, the bracket also includes a first mounting portion, a second mounting portion, a first connecting portion, a second connecting portion, a first anti-rotation protrusion and a second anti-rotation protrusion. Along the width direction of the lower insulating part, the first mounting portion and the second mounting portion are respectively located on opposite sides of the shielding portion. Along the thickness direction of the end cover assembly, the first mounting portion and the second mounting portion are both located on one side of the shielding portion and are both spaced apart from the shielding portion. The first mounting portion has a third side and a fourth side, and the third side and the fourth side are arranged back to back. The second mounting portion has a fifth side and a sixth side, and the fifth side and the third side are located on the same side of the bracket, and the sixth side is arranged back to back with the fifth side, and is located on the same side of the bracket as the fourth side.

[0020] The first connecting portion is connected between the shielding portion and the first mounting portion, and the second connecting portion is connected between the shielding portion and the second mounting portion.

[0021] The first anti-rotation protrusion is fixedly connected to one end of the first mounting portion away from the shielding portion and is provided on the third side surface. The second anti-rotation protrusion is fixedly connected to one end of the second mounting portion away from the shielding portion and is provided on the sixth side surface.

[0022] The design of the first anti-rotation protrusion and the second anti-rotation protrusion can increase the end width of the bracket. It should be understood that there is a gap between the end cover assembly and the shell in the energy storage device, and when the energy storage device is in thermal runaway, the gas inside the energy storage device will impact the bracket to cause the bracket to rotate. Since the end width of the bracket is large, the bracket cannot rotate further after contacting the shell. The design of the first anti-rotation protrusion and the second anti-rotation protrusion can maintain the position of the bracket in the end cover assembly, thereby improving the safety and stability of the energy storage device.

[0023] The shielding portion has a shielding surface facing away from the second surface, and the shielding surface is provided with an insulating film to avoid short circuit between the shielding portion and the cell assembly of the energy storage device, thereby ensuring the use reliability of the energy storage device.

[0024] When the energy storage device is in thermal runaway, if the gap between the cathode diaphragm and the anode diaphragm in the cell assembly and the shielding portion is small, electrical breakdown and arc may occur, which may ignite combustible substances. The design of the insulating film can avoid electrical breakdown between the shielding portion and the cathode diaphragm and the anode diaphragm, thereby improving the use safety of the energy storage device.

[0025] The lower insulating piece is provided with a mounting groove, and the opening of the mounting groove is located on the first surface. The mounting groove includes the through hole, and the bracket is mounted in the mounting groove to reduce the space occupation of the bracket in the thickness direction of the end cover assembly, thereby reducing the thickness of the end cover assembly and the space occupation of the end cover assembly in the height direction, reserving more space for the cell assembly, and helping to improve the capacity of the energy storage device.

[0026] The bracket is located on the side of the first surface facing the second surface. In other words, the bracket does not protrude relative to the first surface to avoid affecting the assembly stability between the lower insulating piece and the end cover, thereby ensuring the structural stability of the end cover assembly.

[0027] The lower insulating piece is provided with a first protrusion and a second protrusion, and the first protrusion and the second protrusion are located on the second surface. Along the width direction of the lower insulating piece, the first protrusion and the second protrusion are respectively located on the opposite sides of the shielding portion and abut against the cell assembly of the energy storage device to avoid shaking of the cell assembly inside the energy storage device, thereby ensuring the structural stability of the energy storage device.

[0028] In a second aspect, the present application provides an energy storage device, comprising a shell, a battery cell assembly and any of the above-mentioned end cover assemblies, the shell being provided with a receiving cavity and an opening, the receiving cavity being provided on the inner side of the shell, the opening being located on the top side of the receiving cavity and being connected to the receiving cavity, the battery cell assembly being received in the receiving cavity, the end cover assembly being installed on the shell and closing the opening.

[0029] In a third aspect, the present application provides an electrical device, comprising the energy storage device described above, wherein the energy storage device supplies power to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0031] Figure 1a This is a schematic structural diagram of an energy storage system according to an embodiment of the present application;

[0032] Figure 1b It is a structural schematic diagram of the energy storage device provided by this application;

[0033] Figure 2 yes Figure 1b A schematic structural diagram of the end cover assembly in the energy storage device shown;

[0034] Figure 3 yes Figure 2 The end cap assembly shown is a schematic structural diagram of the first embodiment after being cut along II;

[0035] Figure 4 yes Figure 2 The end cap assembly is shown as a schematic diagram of an exploded structure in a first embodiment;

[0036] Figure 5 yes Figure 4 A schematic structural diagram of the end cap in the end cap assembly shown;

[0037] Figure 6 yes Figure 4 A schematic structural diagram of the lower insulating member in the end cap assembly shown;

[0038] Figure 7 yes Figure 6 A schematic structural diagram of the lower insulating member shown at another angle;

[0039] Figure 8 yes Figure 4 A schematic diagram of the structure of the bracket in the end cover assembly shown;

[0040] Figure 9 yes Figure 4 A schematic diagram of the assembly structure of the lower insulating member and the bracket in the end cap assembly shown;

[0041] Figure 10 yes Figure 9 A schematic structural diagram of the assembly structure shown at another angle;

[0042] Figure 11 yes Figure 9 The schematic diagram of the structure of the assembly structure after being cut along II-II;

[0043] Figure 12 yes Figure 4 A schematic diagram of the assembly structure of the lower insulating member, bracket and end cover in the end cover assembly shown;

[0044] Figure 13 yes Figure 2 The end cap assembly shown is a schematic structural diagram of the second embodiment after being cut along II;

[0045] Figure 14 yes Figure 13 A schematic diagram of the structure of the bracket in the end cover assembly shown;

[0046] Figure 15 yes Figure 13 A schematic diagram of the assembly structure of the lower insulating member and the bracket in the end cap assembly shown;

[0047] Figure 16 yes Figure 15 A schematic structural diagram of the assembly structure shown at another angle;

[0048] Figure 17 yes Figure 15 The schematic diagram of the structure of the assembly structure after being cut along III-III;

[0049] Figure 18 yes Figure 13 Schematic diagram of the assembly structure of the lower insulation, bracket and end cover in the end cover assembly shown.

[0050] The names corresponding to the reference numerals in the figures are:

[0051] Energy storage system 400, high-voltage cable 410, first power conversion device 420, second power conversion device 430, energy storage device 100, housing 110, end cover assembly 120, end cover 10, explosion-proof valve 20, protective sheet 30, lower insulator 40, bracket 50, pole 60, upper insulator 70, welding ring 80, sealing ring 90, explosion-proof hole 101, second mounting hole 102, first surface 401, second surface 402, peripheral side surface 403, first sub-peripheral side surface 4031, second sub-peripheral side surface 4032, mounting groove 404, first mounting hole 405, through hole 4041, first sub-mounting groove 4042, second sub-mounting groove 4043, third sub-mounting groove 4044, fourth sub-mounting groove 4045, first hole wall surface 404a, second hole wall surface 404b, first groove side wall surface 404c, Second groove side wall surface 404d, third groove side wall surface 404e, fourth groove side wall surface 404f, first protrusion 41, second protrusion 42, first protrusion surface 411, second protrusion surface 421, first groove 406, second groove 407, first air vent 408, second air vent 409, shielding portion 51, first mounting portion 52, second mounting portion 53, first connecting portion 54, second connecting portion 55, first anti-rotation protrusion 56, second anti-rotation protrusion 57, first side surface 511, second side surface 512, shielding surface 513, third side surface 521, fourth side surface 522, fifth side surface 531, sixth side surface 532, seventh side surface 541, eighth side surface 542, ninth side surface 551, tenth side surface 552, first baffle portion 58, second baffle portion 59, first notch 514 and second notch 515. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application.

[0053] Since the energy people need is highly time- and space-dependent, in order to rationally utilize energy and improve energy utilization, it is necessary to use a medium or device to store one form of energy in the same form or convert it into another form of energy, and then release it in a specific form based on future application needs. Currently, the main way to generate green electricity is to develop green energy such as photovoltaics and wind power to replace fossil energy.

[0054] Currently, the generation of green electricity generally relies on photovoltaics, wind power, and hydropower. However, wind and solar energy are generally intermittent and highly volatile, which can cause grid instability, insufficient electricity during peak hours, and excessive electricity during off-peak hours. Unstable voltage can also damage electricity. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar power curtailment". To solve these problems, we must rely on energy storage. This means converting electrical energy into other forms of energy through physical or chemical means and storing them. When needed, this energy is converted into electrical energy and released. Simply put, energy storage is like a large "power bank", storing electricity when photovoltaic and wind energy are sufficient and releasing the stored electricity when needed.

[0055] Taking electrochemical energy storage as an example, this solution provides an energy storage device 100 for use in energy storage systems. The energy storage device 100 is equipped with a group of chemical batteries, which mainly use the chemical elements in the batteries as energy storage media. The charging and discharging process is accompanied by chemical reactions or changes in the energy storage medium. Simply put, the electricity generated by wind and solar energy is stored in the chemical batteries. When the use of external electricity reaches a peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0056] Currently, energy storage (i.e., energy storage) has a wide range of application scenarios, including power generation side energy storage, grid side energy storage, and power consumption side energy storage. The corresponding types of energy storage devices 100 include:

[0057] (1) Large-scale energy storage power stations applied to wind power and photovoltaic power stations can help renewable energy generation meet grid connection requirements and improve the utilization rate of renewable energy. As a high-quality active / reactive power supply on the power supply side, energy storage power stations can achieve load matching of electricity in time and space, enhance the ability to absorb renewable energy, reduce instantaneous power changes, reduce the impact on the power grid, improve the absorption of new energy generation, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation.

[0058] (2) Energy storage containers used on the grid side are mainly used for peak load regulation, frequency regulation, and relief of grid congestion. They can realize peak load 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 load period, thereby achieving a balance between electricity production and consumption;

[0059] (3) Small energy storage cabinet applied to power consumption side, the main functions are power self-generation and self-use, peak-valley price difference arbitrage, capacity cost management and improvement of power supply reliability. According to different application scenarios, the energy storage of power consumption side can be divided into industrial and commercial energy storage cabinet, household energy storage device, energy storage charging pile, etc., which is generally used with distributed photovoltaic. Industrial and commercial users can use energy storage for valley-peak price difference arbitrage and capacity cost management. In the electricity market implementing peak-valley electricity price, through charging the energy storage system at low electricity price and discharging the energy storage system at high electricity price, the peak-valley price difference arbitrage is realized, and the electricity cost is reduced. In addition, for industrial enterprises applying two-part electricity price, the energy storage system can be used to store energy at low electricity consumption and discharge at peak load, so as to reduce the maximum demand amount of sharp peak power and report, and achieve the purpose of reducing capacity electricity cost. Household photovoltaic with storage can improve the level of power self-generation and self-use. Due to high electricity price and poor power supply stability, the demand for household photovoltaic installation is increased. Considering that photovoltaic generates electricity in the daytime and users generally have high load at night, through the configuration of energy storage, photovoltaic power can be better utilized, the level of self-generation and self-use is improved, and the electricity cost is reduced. In addition, communication base stations, data centers and other fields need to configure energy storage for backup power supply.

[0060] In some embodiments, referring to Figure 1a , Figure 1a FIG. 4 is a structural schematic diagram of an energy storage system 400 according to an embodiment of the present application, and the present application Figure 1a The present application energy storage device 100 is not limited to the power generation / distribution side energy storage scenario.

[0061] The present application provides an energy storage system 400, which includes: a high-voltage cable 410, a first power conversion device 420, a second power conversion device 430 and the energy storage device 100 provided in the present application. In some embodiments of the power generation side scenario, the second power conversion device 430 can be a wind power conversion device. Since the power generated by wind power conversion is volatile, random and intermittent, the unstable power output by the wind power conversion device can be stored in the energy storage device 100 by connecting to the grid. The energy storage device 100 is connected to the high-voltage cable 410 and outputs smooth power to the power distribution network side for use, thereby realizing peak and frequency regulation and stable operation of the power grid; or, wind power The conversion device is always connected to the high-voltage cable 410. Under normal power generation conditions, the electric energy output by the wind power conversion device is supplied to the power 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 the energy storage device 100, reducing the wind and solar power abandonment rates and improving the problem of new energy power generation and consumption. When the power load is high, the power grid issues an instruction to use the power stored in the energy storage device 100 in conjunction with the high-voltage cable 410 in a grid-connected mode to transmit the power to the power distribution network for use, providing peak-shaving, frequency regulation, standby and other services for the 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.

[0062] In some embodiments on the distribution network side, the first power conversion device 420 can be a photovoltaic power conversion device, and the energy storage device 100 is connected to the high-voltage cable 410 and installed between the downstream of the high-voltage cable 410 and the user load. The electric energy output by the photovoltaic power conversion device is stored in the energy storage device 100, which responds promptly to act as a backup power supply when a fault occurs in the power grid / distribution network; or, it can alleviate line congestion when a line congestion occurs in the high-voltage cable 410 transmission line, and provide power supply support when the power grid is planned to be expanded to delay the economic pressure caused by the expansion of the power grid / distribution network.

[0063] Optionally, the first electric energy conversion device may include but is not limited to a wind power conversion device, and the second electric energy conversion device may include but is not limited to a photovoltaic power conversion device. The first electric energy conversion device 420 and the second electric energy conversion device 430 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy and mechanical energy into electric energy.

[0064] Optionally, the energy storage device 100 may include but is not limited to energy storage application scenarios 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 used in data centers, military equipment, aerospace, charging piles, electric vehicles and other fields.

[0065] Optionally, the energy storage device 100 may include, but is not limited to, a single cell, or a battery module, battery pack, battery cluster, mobile power supply, energy storage cabinet / container, or other integrated battery system composed of single cells. The energy storage device 100 provided in the embodiments of this application may be applied in, but is not limited to, the products listed above. Other application forms are also possible. The embodiments of this application do not impose strict limitations on the application form of the energy storage device 100. The embodiments of this application illustrate the energy storage device 100 as a multi-cell battery.

[0066] Optionally, when the energy storage device 100 is a single battery, the energy storage device 100 may be, but is not limited to, at least one of a cylindrical battery, a square battery, a prismatic battery, or batteries of other shapes.

[0067] See also Figure 1b , Figure 1b 1 is a schematic diagram of the structure of the energy storage device 100 provided in this application. For ease of description, the width direction of the energy storage device 100 is defined as the X-axis direction, the length direction of the energy storage device 100 is defined as the Y-axis direction, and the height direction of the energy storage device 100 is defined as the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are mutually perpendicular.

[0068] The present application provides an energy storage device 100, which may include but is not limited to single cells, battery modules, battery packs, battery systems, etc. Among them, the single cell may be a secondary battery, which refers to a battery that can continue to be used by activating the active material by charging after the battery cell is discharged. The single cell may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery or a lead-acid battery, etc., and the present application does not make specific limitations on this. It should be noted that the actual application form of the energy storage device 100 provided in the present application may be, but is not limited to, the listed products, and may also be other application forms. The present application does not strictly limit the application form of the energy storage device 100. The present application takes the energy storage device 100 as a square battery as an example for explanation.

[0069] The energy storage device 100 includes a shell 110, a battery cell assembly (not shown) and an end cover assembly 120. The shell 110 is provided with a receiving cavity (not shown) and an opening (not shown). The receiving cavity is provided on the inner side of the shell 110 and contains an electrolyte. The opening is located on the top side of the receiving cavity and is connected to the receiving cavity. The shell 110 can be made of aluminum, for example, the shell 110 can be an aluminum shell. The battery cell assembly is accommodated in the receiving cavity. The battery cell assembly can be immersed in the electrolyte. The end cover assembly 120 is installed on the shell 110, closes the opening, and is electrically connected to the battery cell assembly. The length direction of the end cover assembly 120 is parallel to the X-axis direction, the width direction of the end cover assembly 120 is parallel to the Y-axis direction, and the thickness direction of the end cover assembly 120 is parallel to the Z-axis direction.

[0070] See also Figures 2 to 4 , Figure 2 yes Figure 1b The schematic structural diagram of the end cover assembly 120 in the energy storage device 100 is shown. Figure 3 yes Figure 2 The end cap assembly 120 is a schematic structural diagram of the first embodiment after being cut along II. Figure 4 yes Figure 2 The end cap assembly 120 is shown as a schematic diagram of the exploded structure in the first embodiment. Here, "cutting along position II" means cutting along the plane where line II is located, and similar descriptions in the following text can be understood in the same way.

[0071] The end cap assembly 120 includes an end cap 10, an explosion-proof valve 20, a protective sheet 30, a lower insulator 40, a bracket 50, a pole 60, an upper insulator 70, a welding ring 80, and a sealing ring 90. The explosion-proof valve 20 and the protective sheet 30 are both mounted on the end cap 10. Along the thickness of the end cap 10, the lower insulator 40 and the bracket 50 are located on the same side of the end cap 10. Along the thickness of the end cap assembly 120, the pole 60 passes through the end cap 10 and the lower insulator 40. There are two poles 60. One pole 60 serves as the positive pole, and the other pole 60 serves as the negative pole.

[0072] The upper insulator 70 is mounted on the side of the end cap 10 facing away from the lower insulator 40 and surrounds the electrode 60. Two upper insulators 70 are provided. They are spaced apart along the length of the end cap assembly 120. One upper insulator 70 serves as the positive electrode upper insulator and surrounds the positive electrode. The other upper insulator 70 serves as the negative electrode upper insulator and surrounds the negative electrode.

[0073] The welding ring 80 is located on the side of the lower insulator 40 facing away from the end cap 10, and is sleeved on the pole 60 and fixedly connected to the pole 60. There are two welding rings 80. One welding ring 80 serves as a positive electrode welding ring and is sleeved on the positive pole and fixedly connected to the positive pole. The other welding ring 80 serves as a negative pole pin and is sleeved on the negative pole and fixedly connected to the negative pole. The sealing ring 90 sleeves on the pole 60 and the upper insulator 70 and is clamped between the end cap 10 and the welding ring 80. There are two sealing rings 90. One sealing ring 90 serves as a positive electrode sealing ring and is sleeved on the positive pole and the positive upper insulator and is clamped between the end cap 10 and the positive welding ring. The other sealing ring 90 serves as a negative electrode sealing ring and is sleeved on the negative pole and the negative upper insulator and is clamped between the end cap 10 and the negative welding ring.

[0074] See also Figure 5 , Figure 5 yes Figure 4A schematic structural diagram of the end cover 10 in the end cover assembly 120 is shown.

[0075] The end cap 10 is provided with an explosion-proof hole 101 and a second mounting hole 102. Both explosion-proof hole 101 and second mounting hole 102 extend through the end cap 10 along its thickness. Specifically, along the length of the end cap 10 (the X-axis in the figure), the explosion-proof hole 101 is located in the middle of the end cap 10. There are two second mounting holes 102. Along the length of the end cap 10, the two second mounting holes 102 are located on opposite sides of the explosion-proof hole 101 and are spaced apart from the explosion-proof hole 101.

[0076] Please also refer to Figure 3 , the explosion-proof valve 20 covers the opening of the explosion-proof hole 101 toward the lower insulating member 40. When the energy storage device 100 experiences thermal runaway, the explosion-proof valve 20 will open, and the high-temperature gas inside the energy storage device 100 will be ejected from the explosion-proof hole 101 to prevent the energy storage device 100 from exploding and ensure the reliability of the energy storage device 100. Among them, the length direction of the explosion-proof valve 20 is parallel to the width direction of the end cap 10 (the Y-axis direction in the figure). The protective sheet 30 covers the opening of the explosion-proof hole 101 away from the lower insulating member 40 to protect the explosion-proof valve 20.

[0077] See also Figure 6 and Figure 7 , Figure 6 yes Figure 4 The schematic structural diagram of the lower insulating member 40 in the end cap assembly 120 is shown. Figure 7 yes Figure 6 A schematic structural diagram of the lower insulating member 40 at another angle.

[0078] The lower insulating member 40 has a first surface 401, a second surface 402, and a peripheral side surface 403. The first surface 401 faces the end cap 10. Along the thickness direction of the lower insulating member 40 (the Z-axis direction in the figure), the second surface 402 is arranged opposite to the first surface 401. The peripheral side surface 403 is connected between the first surface 401 and the second surface 402. The peripheral side surface 403 includes a first sub-circumferential side surface 4031 and a second sub-circumferential side surface 4032. Along the width direction of the lower insulating member 40 (the Y-axis direction in the figure), the first sub-circumferential side surface 4031 and the second sub-circumferential side surface 4032 are arranged opposite to each other.

[0079] The lower insulator 40 is provided with a mounting slot 404 and a first mounting hole 405. The opening of the mounting slot 404 is located on the first surface 401. The mounting slot 404 is recessed from the first surface 401 toward the second surface 402 (the negative Z-axis direction in the figure). Along the length of the lower insulator 40 (the X-axis direction in the figure), the mounting slot 404 is located in the middle of the lower insulator 40. The length of the mounting slot 404 is parallel to the width of the lower insulator 40, and the width of the mounting slot 404 is parallel to the length of the lower insulator 40.

[0080] In this embodiment, the mounting slot 404 includes a through hole 4041, a first sub-mounting slot 4042, a second sub-mounting slot 4043, a third sub-mounting slot 4044, and a fourth sub-mounting slot 4045. Along the length of the mounting slot 404, the through hole 4041 is located in the middle of the mounting slot 404 and extends through the first surface 401 and the second surface 402. The through hole 4041 has a first hole wall 404a and a second hole wall 404b. Along the length of the mounting slot 404, the first hole wall 404a and the second hole wall 404b are spaced apart and arranged opposite each other.

[0081] Along the length of the mounting groove 404, the first sub-mounting groove 4042 and the second sub-mounting groove 4043 are located on opposite sides of the through-hole 4041, are connected to the through-hole 4041, and both extend through the peripheral side surface 403. Specifically, the first sub-mounting groove 4042 extends through the first sub-peripheral side surface 4031, and the second sub-mounting groove 4043 extends through the second sub-peripheral side surface 4032. The first sub-mounting groove 4042 has a first groove sidewall surface 404c and a second groove sidewall surface 404d. The second sub-mounting groove 4043 has a third groove sidewall surface 404e and a fourth groove sidewall surface 404f. Along the length of the lower insulator 40, the first groove sidewall surface 404c and the second groove sidewall surface 404d are spaced apart and arranged opposite each other, while the third groove sidewall surface 404e and the fourth groove sidewall surface 404f are spaced apart and arranged opposite each other. The first hole wall surface 404a is connected between the first groove sidewall surface 404c and the third groove sidewall surface 404e. The second hole wall surface 404b is connected between the second groove side wall surface 404d and the fourth groove side wall surface 404f.

[0082] The third sub-mounting groove 4044 is located at the end of the first sub-mounting groove 4042 away from the through-hole 4041 and is in communication with the first sub-mounting groove 4042. Along the width direction of the mounting groove 404, the third sub-mounting groove 4044 is located on one side of the first sub-mounting groove 4042 and extends through the second surface 402, the first sub-peripheral side surface 4031, and the first groove sidewall surface 404c. The fourth sub-mounting groove 4045 is located at the end of the second sub-mounting groove 4043 away from the through-hole 4041 and is in communication with the through-hole 4041. Along the width direction of the mounting groove 404, the fourth sub-mounting groove 4045 is located on one side of the second sub-mounting groove 4043 and extends through the second surface 402, the second sub-peripheral side surface 4032, and the fourth groove sidewall surface 404f.

[0083] The first mounting holes 405 extend through the first surface 401 and the second surface 402. There are two first mounting holes 405. Along the length of the lower insulator 40, the two first mounting holes 405 are located on opposite sides of the mounting groove 404 and are spaced apart from the mounting groove 404.

[0084] The lower insulating member 40 is provided with a first protrusion 41 and a second protrusion 42. The first protrusion 41 and the second protrusion 42 are both provided on the second surface 402 and protrude from the second surface 402 in a direction away from the first surface 401 (in the negative direction of the Z axis as shown). They are used to abut the battery cell assembly to prevent the battery cell assembly from shaking inside the energy storage device 100 and ensure the structural stability of the energy storage device 100. Along the length direction of the lower insulating member 40, the first protrusion 41 and the second protrusion 42 are both located in the middle of the lower insulating member 40. Along the width direction of the lower insulating member 40, the first protrusion 41 and the second protrusion 42 are respectively located on opposite sides of the through hole 4041. Specifically, the first protrusion 41 is located on the side of the through hole 4041 facing the first sub-circumferential side surface 4031 and is arranged corresponding to the first sub-mounting groove 4042. The second protrusion 42 is located on the side of the through hole 4041 facing the second sub-circumferential side surface 4032 and is arranged corresponding to the second sub-mounting groove 4043. The first protrusion 41 has a first protrusion surface 411 facing away from the second surface 402, and the first protrusion surface 411 is used to abut against the battery cell assembly. The second protrusion 42 has a second protrusion surface 421 facing away from the second surface 402, and the second protrusion surface 421 is used to abut against the battery cell assembly.

[0085] The lower insulating member 40 is further provided with a first recess 406, a second recess 407, a first air vent 408, and a second air vent 409. The first recess 406 has an opening on the bottom wall surface (not labeled in the figure) of the first sub-mounting groove 4042. The first recess 406 is recessed from the bottom wall surface of the first sub-mounting groove 4042 towards the direction of the first protruding surface 411 (the negative direction of the Z-axis shown in the figure) and is in communication with the first sub-mounting groove 4042. The first recess 406 is arranged in correspondence with the first protrusion 41. The second recess 407 has an opening on the bottom wall surface (not labeled in the figure) of the second sub-mounting groove 4043. The second recess 407 is recessed from the bottom wall surface of the second sub-mounting groove 4043 towards the direction of the second protruding surface 421 (the negative direction of the Z-axis shown in the figure) and is in communication with the second sub-mounting groove 4043. The second recess 407 is arranged in correspondence with the second protrusion 42.

[0086] The first air vent 408 penetrates the bottom wall surface (not labeled in the figure) of the first recess 406 and the first protruding surface 411. The first air vent 408 has a plurality of air vents, and the plurality of air vents are arranged at intervals. The second air vent 409 penetrates the bottom wall surface (not labeled in the figure) of the second recess 407 and the second protruding surface 421. The second air vent 409 has a plurality of air vents, and the plurality of air vents are arranged at intervals.

[0087] Please refer to Figure 8 , Figure 8 is Figure 4 the structural diagram of the bracket 50 in the end cover assembly 120 shown in the figure. The length direction of the bracket 50 is parallel to the Y-axis direction, the width direction of the bracket 50 is parallel to the X-axis direction, and the thickness direction of the bracket 50 is parallel to the Z-axis direction.

[0088] In this embodiment, the bracket 50 can be made of aluminum. In other embodiments, the bracket 50 can also be made of other heat-resistant materials. The heat-resistant material can be a metal material, or the heat-resistant material can be an inorganic material such as ceramic. The bracket 50 includes a shielding portion 51, a first mounting portion 52, a second mounting portion 53, a first connecting portion 54, a second connecting portion 55, a first anti-rotation protrusion 56, and a second anti-rotation protrusion 57. The first connecting portion 54 is fixedly connected between the shielding portion 51 and the first mounting portion 52. The second connecting portion 55 is fixedly connected between the shielding portion 51 and the second mounting portion 53. The first anti-rotation protrusion 56 is fixedly connected to one end of the first mounting portion 52 away from the shielding portion 51. The second anti-rotation protrusion 57 is fixedly connected to one end of the second mounting portion 53 away from the shielding portion 51. The shielding portion 51, the first mounting portion 52, the second mounting portion 53, the first connecting portion 54, the second connecting portion 55, the first anti-rotation protrusion 56, and the second anti-rotation protrusion 57 can be integrally formed.

[0089] Along the length direction of the bracket 50, the shielding portion 51 is located in the middle of the bracket 50. The shielding portion 51 includes a first side surface 511, a second side surface 512 and a shielding surface 513. Along the width direction of the bracket 50, the first side surface 511 and the second side surface 512 are arranged back to back. The shielding surface 513 is connected between the first side surface 511 and the second side surface 512. Among them, an insulating film is provided on the shielding surface 513 (not shown). It should be noted that the insulating film can be formed by performing an insulating treatment such as anodizing on the bracket 50, and this application does not impose specific restrictions on this.

[0090] The first mounting portion 52 and the second mounting portion 53 are both located on the side of the shielding portion 51 facing away from the shielding surface 513. Along the length of the bracket 50, the first mounting portion 52 and the second mounting portion 53 are located on opposite sides of the shielding portion 51. The first mounting portion 52 has a third side 521 and a fourth side 522. The second mounting portion 53 has a fifth side 531 and a sixth side 532. Along the width of the bracket 50, the third side 521 and the fourth side 522 are opposite each other, while the fifth side 531 and the sixth side 532 are opposite each other. Along the width of the bracket 50, the first side 511, the third side 521, and the fifth side 531 are located on the same side of the bracket 50, while the second side 512, the fourth side 522, and the sixth side 532 are located on the same side of the bracket 50. Along the length of the bracket 50, the third side 521 and the fifth side 531 are located on opposite sides of the first side 511, and the fourth side 522 and the sixth side 532 are located on opposite sides of the second side 512.

[0091] Along the length of the bracket 50, the first connecting portion 54 and the first mounting portion 52 are located on the same side of the shielding portion 51, while the second connecting portion 55 and the second mounting portion 53 are located on the same side of the shielding portion 51. Along the thickness of the bracket 50, the first connecting portion 54 is located between the shielding portion 51 and the first mounting portion 52, while the second connecting portion 55 is located between the shielding portion 51 and the second mounting portion 53. The first connecting portion 54 has a seventh side surface 541 and an eighth side surface 542. The seventh side surface 541 is connected between the first side surface 511 and the third side surface 521. The eighth side surface 542 is connected between the second side surface 512 and the fourth side surface 522, and is opposite to the seventh side surface 541. The second connecting portion 55 has a ninth side surface 551 and a tenth side surface 552. The ninth side surface 551 is connected between the first side surface 511 and the fifth side surface 531. The tenth side surface 552 is connected between the second side surface 512 and the sixth side surface 532, and is opposite to the ninth side surface 551.

[0092] In addition, both the first connecting portion 54 and the second connecting portion 55 are folded relative to the shielding portion 51, and the angle between them and the shielding portion 51 is greater than 0 degrees and less than 180 degrees. Exemplarily, the angle between the first connecting portion 54 and the second connecting portion 55 and the shielding portion 51 is 90 degrees. The first connecting portion 54 is also folded relative to the first mounting portion 52, and the angle between them and the first mounting portion 52 is greater than 0 degrees and less than 180 degrees. The second connecting portion 55 is also folded relative to the second mounting portion 53, and the angle between them and the second mounting portion 53 is greater than 0 degrees and less than 180 degrees. Exemplarily, the angle between the first connecting portion 54 and the first mounting portion 52 is 90 degrees, and the angle between the second connecting portion 55 and the second mounting portion 53 is 90 degrees.

[0093] The first anti-rotation protrusion 56 is provided on the third side surface 521 and protrudes from the third side surface 521 away from the fourth side surface 522. The second anti-rotation protrusion 57 is fixedly connected to the sixth side surface 532 and protrudes from the sixth side surface 532 away from the fifth side surface 531. The first anti-rotation protrusion 56 and the second anti-rotation protrusion 57 are provided on opposite sides of the bracket 50 along the width direction of the bracket 50 to increase the width of the bracket 50 at its distal end.

[0094] It should be understood that in the energy storage device 100, a gap exists between the bracket 50 and the housing 110. If thermal runaway occurs in the energy storage device 100, the gas within the device 100 will impact the bracket 50, causing it to rotate. Due to the wide end width of the bracket 50, once the bracket 50 rotates to the point of contact with the housing 110, it cannot rotate further. The design of the first anti-rotation protrusion 56 and the second anti-rotation protrusion 57 maintains the position of the bracket 50 within the end cap assembly 120, thereby improving the safety and stability of the energy storage device 100. In other embodiments, the bracket 50 may further include a third anti-rotation protrusion and a fourth anti-rotation protrusion, with the third anti-rotation protrusion being located on the fourth side surface 522 and the fourth anti-rotation protrusion being located on the fifth side surface 531. This is not specifically limited in this application.

[0095] Please also refer to Figures 9 to 11 , Figure 9 yes Figure 4 The schematic diagram of the assembly structure of the lower insulating member 40 and the bracket 50 in the end cover assembly 120 is shown. Figure 10 yes Figure 9 The schematic diagram of the assembly structure shown is from another angle. Figure 11 yes Figure 9 The schematic diagram of the structure of the assembly structure after being cut apart along II-II is shown.

[0096] The bracket 50 is installed in the mounting groove 404 and is passed through the through hole 4041. It should be noted that the bracket 50 can be installed in the mounting groove 404 by hot melting, snapping or bonding, or the bracket 50 can also be fixedly installed on the end cover 10. This application does not impose any specific restrictions on this. The bracket 50 can reuse at least part of the thickness space of the lower insulating member 40 to reduce the space occupied by the bracket 50 in the thickness direction of the end cover assembly 120, thereby reducing the thickness dimension of the end cover assembly 120, and further reducing the space occupied by the end cover assembly 120 in the height direction of the energy storage device 100, which can reserve more space for the battery cell assembly, and help to increase the capacity of the energy storage device 100.

[0097] In this embodiment, the bracket 50 is located on the side of the first surface 401 facing the second surface 402. In other words, the bracket 50 does not protrude relative to the first surface 401, thereby preventing the bracket 50 from protruding relative to the first surface 401 and affecting the assembly stability between the lower insulator 40 and the end cap 10, thereby ensuring the structural stability of the end cap assembly 120. The melting point of the bracket 50 is greater than the melting point of the lower insulator 40.

[0098] Specifically, the shielding portion 51 is located on the side of the second surface 402 away from the first surface 401, and is spaced apart from the second surface 402 in the thickness direction of the lower insulating member 40, and is arranged opposite to the through hole 4041. Along the width direction of the lower insulating member 40, the shielding portion 51 is located between the first protrusion 41 and the second protrusion 42. Among them, the first side surface 511 faces the plane where the first hole wall surface 404a is located, and the second side surface 512 faces the plane where the second hole wall surface 404b is located. The shielding surface 513 faces away from the second surface 402 and has the same orientation as the first raised surface 411 and the second raised surface 421. Exemplarily, the shielding surface 513 is flush with the first raised surface 411 and the second raised surface 421, and abuts the battery cell assembly to prevent the battery cell assembly from shaking inside the energy storage device 100, thereby ensuring the structural stability of the energy storage device 100.

[0099] Because shielding surface 513 is provided with an insulating film, it prevents direct contact between shielding portion 51 and the cell assembly, which could cause a short circuit, thereby ensuring the reliability of energy storage device 100. Furthermore, if thermal runaway of energy storage device 100 occurs, the separators in the cell assembly melt, and the gaps between the cathode and anode diaphragms in the cell assembly and shielding portion 51 are relatively small, which can easily lead to electrical breakdown and arcing. Arcing can ignite combustible materials. The design of the insulating film also prevents electrical breakdown between shielding portion 51 and the cathode and anode diaphragms, thereby improving the safety of energy storage device 100.

[0100] The first mounting portion 52 is mounted in the first sub-mounting groove 4042 and covers the first protrusion 41 and the first groove 406. The third side surface 521 is located on the same side of the bracket 50 as the first side surface 511, facing the first groove sidewall surface 404c and opposite to the first groove sidewall surface 404c. The fourth side surface 522 is located on the same side of the bracket 50 as the second side surface 512, facing the second groove sidewall surface 404d and opposite to the second groove sidewall surface 404d. The second mounting portion 53 is mounted in the second sub-mounting groove 4043 and covers the second protrusion 42 and the second groove 407. The fifth side surface 531 is located on the same side of the bracket 50 as the third side surface 521, facing the third groove sidewall surface 404e and opposite to the third groove sidewall surface 404e. The sixth side surface 532 is located on the same side of the bracket 50 as the fourth side surface 522, facing the fourth groove sidewall surface 404f and opposite to the fourth groove sidewall surface 404f.

[0101] The first connecting portion 54 and the second connecting portion 55 are both inserted into the through hole 4041. The first anti-rotation protrusion 56 is mounted in the third sub-mounting groove 4044. The second anti-rotation protrusion 57 is mounted in the fourth sub-mounting groove 4045. The structure of the first anti-rotation protrusion 56 matches that of the third sub-mounting groove 4044, and the structure of the second anti-rotation protrusion 57 matches that of the fourth sub-mounting groove 4045.

[0102] See also Figure 3 and Figure 12 , Figure 12 yes Figure 4 The schematic diagram of the assembly structure of the lower insulating member 40, the bracket 50 and the end cap 10 in the end cap assembly 120 is shown. Figure 3 and Figure 12 The dashed line with an arrow in the middle represents the flow path of the high-temperature gas when thermal runaway occurs in the energy storage device 100 .

[0103] The end cap 10 is located on the side of the first surface 401 away from the second surface 402. The explosion-proof hole 101 is arranged opposite to the shielding portion 51 of the bracket 50, and each second mounting hole 102 is connected to the corresponding first mounting hole 405. The orthographic projection of the explosion-proof valve 20 on the bracket 50 covers at least a portion of the shielding portion 51. Each pole 60 is inserted through the corresponding second mounting hole 102 and the corresponding first mounting hole 405. Each upper insulating member 70 is inserted through the corresponding second mounting hole 102 and the corresponding first mounting hole 405, and is arranged around the corresponding pole 60. Each welding ring 80 is located on the side of the second surface 402 away from the first surface 401. Each sealing ring 90 is inserted through the corresponding first mounting hole 405 and is clamped between the surface of the end cap 10 facing the lower insulating member 40 and the surface of the corresponding welding ring 80 facing the lower insulating member 40.

[0104] It should be noted that when thermal runaway occurs in the energy storage device 100, the explosion-proof valve 20 will open first, the reaction inside the battery cell assembly will continue, and the temperature inside the energy storage device 100 will continue to rise. Not only will the lower insulating member 40 melt at high temperature to form carbonized debris, but the positive electrode foil in the battery cell assembly will also melt at high temperature to form molten aluminum beads. Both the carbonized debris and the molten aluminum beads will be ejected from the explosion-proof hole 101 along with the high-temperature gas. Since the temperature of the molten aluminum beads is as high as 600°C, the molten aluminum beads are easily ignited and caught fire after coming into contact with the carbonized debris.

[0105] In this embodiment, because the melting point of the bracket 50 is greater than that of the lower insulating member 40, when thermal runaway occurs in the energy storage device 100 and the lower insulating member 40 melts, the bracket 50 does not deform. The shielding portion 51 of the bracket 50 is always disposed opposite the through-hole 4041. Therefore, the high-temperature gas inside the energy storage device 100 cannot be ejected directly from the through-hole 4041 through the explosion-proof hole 101 along the thickness direction of the end cap assembly 120. Instead, the high-temperature gas can only enter the through-hole 4041 through the gap between the first side surface 511 and the first hole wall 404a and the gap between the second side surface 512 and the second hole wall 404b and then be ejected through the explosion-proof hole 101. The shielding portion 51 can block the molten aluminum beads, preventing the molten aluminum beads from being ejected directly from the through-hole 4041 and then through the explosion-proof hole 101, contacting carbonized debris and igniting a fire. This can thereby prevent the energy storage device 100 from igniting a fire when thermal runaway occurs, reduce the safety risks of the energy storage device 100, and improve the reliability of the energy storage device 100.

[0106] See also Figure 13 and Figure 14 , Figure 13 yes Figure 2 The end cap assembly 120 is a schematic structural diagram of the second embodiment after being cut along II. Figure 14 yes Figure 13 A schematic structural diagram of the bracket 50 in the end cover assembly 120 is shown.

[0107] The end cover assembly 120 shown in the embodiment is different from the first end cover assembly 120 described above in that the bracket 50 further comprises a first baffle portion 58 and a second baffle portion 59. The first baffle portion 58 and the second baffle portion 59 are fixedly connected to opposite sides of the shielding portion 51 along the width direction of the bracket 50, and extend from the shielding portion 51 to the direction of the first mounting portion 52 to the second mounting portion 53. Specifically, the first baffle portion 58 is fixedly connected to the first side surface 511. The second baffle portion 59 is fixedly connected to the second side surface 512. The first baffle portion 58 and the second baffle portion 59 are completely staggered along the width direction of the lower insulating piece 40 to reduce the shielding of the high-temperature gas by the first baffle portion 58 and the second baffle portion 59. It should be noted that the first baffle portion 58 and the second baffle portion 59 are completely staggered along the width direction of the lower insulating piece 40, which means that the orthographic projection of the first baffle portion 58 on the projection plane does not coincide with the orthographic projection of the second baffle portion 59 on the projection plane, wherein the projection plane is parallel to the width direction of the lower insulating piece 40 and the thickness direction of the lower insulating piece 40.

[0108] In other embodiments, the first baffle portion 58 and the second baffle portion 59 can also be staggered along the length direction of the lower insulating piece 40, which is not limited in the present application. It should be noted that the first baffle portion 58 and the second baffle portion 59 are staggered along the width direction of the lower insulating piece 40, which means that the orthographic projection of the first baffle portion 58 on the projection plane at least partially coincides with the orthographic projection of the second baffle portion 59 on the projection plane, wherein the projection plane is parallel to the width direction of the lower insulating piece 40 and the thickness direction of the lower insulating piece 40.

[0109] In other embodiments, the first baffle portion 58 and the second baffle portion 59 can also be staggered along the length direction of the lower insulating piece 40, which is not limited in the present application. It should be noted that the first baffle portion 58 and the second baffle portion 59 are staggered along the width direction of the lower insulating piece 40, which means that the orthographic projection of the first baffle portion 58 on the projection plane at least partially coincides with the orthographic projection of the second baffle portion 59 on the projection plane, wherein the projection plane is parallel to the width direction of the lower insulating piece 40 and the thickness direction of the lower insulating piece 40.

[0110] In the embodiment, the first baffle portion 58 and the second baffle portion 59 are folded relative to the shielding portion 51, and the included angle between the first baffle portion 58 and the second baffle portion 59 and the shielding portion 51 is greater than 0 degrees and less than 180 degrees. For example, the included angle between the first baffle portion 58 and the second baffle portion 59 and the shielding portion 51 is 90 degrees.

[0111] The bracket 50 also has a first notch 514 and a second notch 515. Both the first notch 514 and the second notch 515 extend through the thickness of the bracket 50 and are located on opposite sides of the bracket 50 along the length of the lower insulator 40, spaced apart from each other. In this embodiment, there are two first notches 514 and two second notches 515. Along the width of the lower insulator 40, the two first notches 514 are spaced apart, and the two second notches 515 are spaced apart.

[0112] Along the length direction of the first baffle portion 58, two first notches 514 are respectively located on opposite sides of the first baffle portion 58 and are adjacent to the first baffle portion 58, and at least one first notch 514 passes through the first side surface 511. It should be noted that the first notch 514 being adjacent to the first baffle portion 58 means that the first notch 514 is adjacent to and connected to the first baffle portion 58, that is, there is no distance between the first notch 514 and the first baffle portion 58. Specifically, one first notch 514 is provided in the shielding portion 51 and passes through the first side surface 511, and the other first notch 514 is provided in the first mounting portion 52 and the first connecting portion 54 and passes through the third side surface 521 and the seventh side surface (not marked in the figure). The first baffle portion 58 is formed by folding relative to the shielding portion 51.

[0113] Along the length direction of the second baffle portion 59, the two second notches 515 are respectively located on opposite sides of the second baffle portion 59 and are adjacent to the second baffle portion 59. It should be noted that the second notch 515 is adjacent to the second baffle portion 59 means that the second notch 515 is adjacent to and connected to the second baffle portion 59, that is, there is no distance between the second notch 515 and the second baffle portion 59. At least one second notch 515 passes through the second side surface 512. Specifically, one second notch 515 is provided in the shielding portion 51 and passes through the second side surface 512, and the other second notch 515 is provided in the second mounting portion 53 and the second connecting portion 55 and passes through the sixth side surface 532 and the tenth side surface (not marked in the figure). Along the width direction of the bracket 50, each first notch 514 and a second notch 515 are correspondingly provided. Among them, the second baffle portion 59 is formed by folding relative to the shielding portion 51.

[0114] The design of the first notch 514 and the second notch 515 not only facilitates the formation of the first baffle portion 58 and the second baffle portion 59, but also avoids the generation of sharp points at the connection positions of the first baffle portion 58 and the second baffle portion 59 and the shielding portion 51 when the first baffle portion 58 and the second baffle portion 59 are folded to form the first baffle portion 58 and the second baffle portion 59. This can prevent the sharp points from scratching operators or other components, and can also prevent the generation of easily falling metal chips that affect the reliability of the energy storage device 100.

[0115] See also Figures 15 to 17 , Figure 15 yes Figure 13The schematic diagram of the assembly structure of the lower insulating member 40 and the bracket 50 in the end cover assembly 120 is shown. Figure 16 yes Figure 15 The schematic diagram of the assembly structure shown is from another angle. Figure 17 yes Figure 15 The schematic diagram of the structure of the assembly structure after being cut apart along III-III is shown.

[0116] In this embodiment, the first baffle portion 58 extends from the shielding portion 51 toward the lower insulating member 40 and is disposed opposite the first hole wall 404a. The first baffle portion 58 partially blocks the gap between the first side surface 511 and the first hole wall 404a. The second baffle portion 59 extends from the shielding portion 51 toward the lower insulating member 40 and is disposed opposite the second hole wall 404b. The second baffle portion 59 partially blocks the gap between the second side surface 512 and the second hole wall 404b.

[0117] See also Figure 13 and Figure 18 , Figure 18 yes Figure 13 The schematic diagram of the assembly structure of the lower insulating member 40, the bracket 50 and the end cap 10 in the end cap assembly 120 is shown. Figure 13 and Figure 18 The dashed line with an arrow in the middle represents the flow path of the high-temperature gas when thermal runaway occurs in the energy storage device 100 .

[0118] It should be noted that when thermal runaway occurs in the energy storage device 100, the high-temperature gas inside the energy storage device 100 is mainly divided into two parts. One part flows from the gap between the first side surface 511 and the first hole wall surface 404a to the through hole 4041, and the other part flows from the gap between the second side surface 512 and the second hole wall surface 404b to the through hole 4041. The two parts of gas will collide in the through hole 4041 and then be ejected from the explosion-proof hole 101.

[0119] In this embodiment, since the bracket 50 is provided with the first baffle portion 58 and the second baffle portion 59 which are staggered, when the energy storage device 100 experiences thermal runaway, a portion of the gas enters the through hole 4041 from the portion of the gap between the first side surface 511 and the first hole wall surface 404a which is not blocked by the first baffle portion 58, and the other portion of the gas flows into the through hole 4041 from the portion of the gap between the second side surface 512 and the second hole wall surface 404b which is not blocked by the second baffle portion 59. The two portions of gas will not collide with each other in the through hole 4041 and cause energy loss. Instead, the two portions of gas form a cross flow, which can effectively The inclined ejection of substances such as carbonized debris, molten aluminum beads, and electrolyte can not only eject the carbonized debris, molten aluminum beads, and electrolyte further, but also prevent the carbonized debris, molten aluminum beads, and electrolyte from accumulating around the explosion-proof hole 101. In addition, since the carbonized debris, molten aluminum beads, and electrolyte have different densities, the ejection distances of substances with different densities will also be different. Therefore, substances with different densities will not accumulate together, which can further reduce the probability of fire, avoid fire when thermal runaway occurs in the energy storage device 100, reduce safety hazards of the energy storage device 100, and improve the reliability of the energy storage device 100.

[0120] The present application also provides an electric device, which includes the energy storage device 100, and the energy storage device 100 supplies power to the electric device. The electric device may be a new energy vehicle, a power storage station, a server, or other equipment requiring electricity.

[0121] The above description is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application; the embodiments of this application and the features of the embodiments can be combined with each other unless there is a conflict. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An end cap assembly for an energy storage device, characterized in that: Includes end cover, explosion-proof valve, lower insulation and bracket; The end cover is provided with an explosion-proof hole, which penetrates the end cover along the thickness direction of the end cover; the explosion-proof valve is installed on the end cover and covers the explosion-proof hole; Along the thickness direction of the end cover, the lower insulating member is located on one side of the end cover, the lower insulating member has a first surface and a second surface, the first surface faces the end cover, and the second surface is arranged opposite to the first surface. The lower insulating member is provided with a through hole, which passes through the first surface and the second surface and is arranged opposite to the explosion-proof valve; The bracket and the lower insulating member are located on the same side of the end cover and are passed through the through hole. The melting point of the bracket is greater than the melting point of the lower insulating member. The bracket includes a shielding portion, which is located on the side of the second surface away from the first surface, and is spaced apart from the second surface in the thickness direction of the lower insulating member and is arranged opposite to the through hole. The orthographic projection of the explosion-proof valve on the bracket covers at least a portion of the shielding portion.

2. The end cap assembly according to claim 1, wherein: The through hole has a first hole wall surface and a second hole wall surface, and along the length direction of the lower insulating member, the first hole wall surface and the second hole wall surface are spaced apart and arranged opposite to each other; The shielding portion has a first side surface and a second side surface, the first side surface faces the plane where the first hole wall surface is located, and the second side surface is arranged opposite to the first side surface and faces the plane where the second hole wall surface is located; The bracket also includes a first baffle portion and a second baffle portion, the first baffle portion is fixedly connected to the first side surface, extends from the shielding portion toward the lower insulating member, and is arranged opposite to the first hole wall surface, the second baffle portion is fixedly connected to the second side surface, extends from the shielding portion toward the lower insulating member, and is arranged opposite to the second hole wall surface, and the first baffle portion and the second baffle portion are staggered along the width direction of the lower insulating member.

3. The end cap assembly according to claim 2, wherein: Along the width direction of the lower insulating member, the first baffle portion and the second baffle portion are completely staggered.

4. The end cap assembly according to claim 3, wherein: Along a width direction of the lower insulator, a sum of a length of the first baffle portion and a length of the second baffle portion is less than or equal to a length of the shielding portion.

5. The end cap assembly according to claim 2, wherein: The first baffle portion and the second baffle portion are both located on a side of the first surface facing the second surface.

6. The end cap assembly according to claim 2, wherein: The bracket is provided with a first notch and a second notch, the first notch and the second notch both pass through the bracket along the thickness direction of the bracket, and are respectively located on opposite sides of the bracket along the length direction of the lower insulating member and are spaced apart from each other; There are two first notches, which are located on opposite sides of the first baffle portion and are adjacent to the first baffle portion. At least one first notch passes through the first side surface, and is formed by folding the first baffle portion relative to the shielding portion. There are two second notches, which are respectively located on opposite sides of the second baffle portion and adjacent to the second baffle portion. At least one second notch passes through the second side surface, and the second baffle portion is folded relative to the shielding portion to form.

7. The end cap assembly according to any one of claims 1 to 6, characterized in that: The bracket further includes a first mounting portion, a second mounting portion, a first connecting portion, a second connecting portion, a first anti-rotation protrusion, and a second anti-rotation protrusion. Along the width direction of the lower insulating member, the first mounting portion and the second mounting portion are respectively located on opposite sides of the shielding portion. Along the thickness direction of the end cover assembly, the first mounting portion and the second mounting portion are both located on one side of the shielding portion and are spaced apart from the shielding portion. The first mounting portion has a third side surface and a fourth side surface, and the third side surface and the fourth side surface are disposed opposite each other. The second mounting portion has a fifth side surface and a sixth side surface, and the fifth side surface and the third side surface are located on the same side of the bracket. The sixth side surface is disposed opposite to the fifth side surface and is located on the same side of the bracket as the fourth side surface. The first connecting portion is connected between the shielding portion and the first mounting portion, and the second connecting portion is connected between the shielding portion and the second mounting portion; The first anti-rotation protrusion is fixedly connected to one end of the first mounting portion away from the shielding portion and is provided on the third side surface. The second anti-rotation protrusion is fixedly connected to one end of the second mounting portion away from the shielding portion and is provided on the sixth side surface.

8. The end cap assembly according to any one of claims 1 to 6, wherein: The shielding portion has a shielding surface facing away from the second surface, and the shielding surface is provided with an insulating film.

9. The end cap assembly according to any one of claims 1 to 6, characterized in that: The lower insulating member is provided with a mounting groove, the opening of the mounting groove is located on the first surface, the mounting groove includes the through hole, and the bracket is mounted in the mounting groove.

10. The end cap assembly according to claim 9, wherein: The bracket is located on a side of the first surface facing the second surface.

11. The end cap assembly according to any one of claims 1 to 6, characterized in that: The lower insulating member is provided with a first protrusion and a second protrusion, and the first protrusion and the second protrusion are both provided on the second surface. Along the width direction of the lower insulating member, the first protrusion and the second protrusion are respectively located on opposite sides of the shielding portion and are used to abut the battery cell assembly of the energy storage device.

12. An energy storage device, characterized in that: It includes a shell, a battery cell assembly and an end cover assembly as described in any one of claims 1 to 11, the shell is provided with a receiving cavity and an opening, the receiving cavity is provided on the inner side of the shell, the opening is located on the top side of the receiving cavity and is connected to the receiving cavity, the battery cell assembly is received in the receiving cavity, and the end cover assembly is installed on the shell and closes the opening.

13. An electrical device, characterized in that: The energy storage device according to claim 12 is included, and the energy storage device supplies power to the electrical equipment.

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