End cover assembly, energy storage device and electric equipment

Abstract

The invention provides an end cover assembly, an energy storage device and electric equipment. In the end cover assembly, an anti-explosion valve is installed on an end cover and covers an anti-explosion hole of the end cover, a lower insulating part is located on the side, away from the first surface, of the second surface, and a through groove penetrates through the third surface and the fourth 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 groove, and the melting point of the support is larger than that of the lower insulating part. The shielding part is located on the side, away from the third surface, of the fourth surface, is spaced from the fourth surface and is opposite to the through groove, the orthographic projection of the anti-explosion valve on the support covers at least part of the shielding part, the first through hole penetrates through the shielding part in the thickness direction of the shielding part, and the first flow guide part is fixedly connected to the first hole wall face and is opposite to the first through hole; in the first flow guide part, the included angle between the first flow guide face and the shielding part is not equal to 90 degrees, and the plane where the first flow guide face is located intersects with an opening, in the first surface, of the anti-explosion hole.

Description

Technical Field

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

[0002] A rechargeable battery, also known as a rechargeable battery or storage battery, is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. The recyclable nature of secondary batteries has made them a key power source for electrical devices. As demand for secondary batteries increases, so too have the demands for their performance, particularly their reliability. When thermal runaway occurs in existing secondary batteries, the explosion-proof valve opens, allowing gas mixed with flammable particles to rise and be ejected from the valve. This can easily ignite and cause a fire, posing a safety hazard to the use of secondary batteries. Summary of the Invention

[0003] The present application provides an end cap assembly, an energy storage device, and an electrical device, which are used to prevent fire when the energy storage device experiences thermal runaway, reduce potential safety hazards of the energy storage device, and improve the reliability of the energy storage device.

[0004] In a first aspect, the present application provides an end cap assembly for use in an energy storage device. The end cap assembly includes an end cap, an explosion-proof valve, a lower insulating member, and a bracket;

[0005] The end cover has a first surface and a second surface. Along the thickness direction of the end cover, the first surface and the second surface are arranged opposite to each other. The end cover is provided with an explosion-proof hole, which passes through the first surface and the second surface.

[0006] The explosion-proof valve is installed on the end cover and covers the explosion-proof hole;

[0007] The lower insulating member is located on a side of the second surface away from the first surface. The lower insulating member has a third surface and a fourth surface. The third surface is arranged opposite to the second surface, and the fourth surface is arranged opposite to the third surface. The lower insulating member is provided with a through groove, which passes through the third surface and the fourth surface and is arranged opposite to the explosion-proof valve.

[0008] The bracket and the lower insulating member are located on the same side of the end cover and pass through the through slot, and the melting point of the bracket is greater than the melting point of the lower insulating member;

[0009] The bracket includes a shielding portion and a first guide portion, the shielding portion is located on a side of the fourth surface facing away from the third surface, and is spaced apart from the fourth surface and opposite to the through groove, the orthographic projection of the explosion-proof valve on the bracket covers at least a portion of the shielding portion, the shielding portion is provided with a first through hole, the first through hole passes through the shielding portion along the thickness direction of the shielding portion, the first through hole has a first hole wall surface and a second hole wall surface, along the length direction of the end cover assembly, the first hole wall surface and the second hole wall surface are spaced apart and opposite to each other, the first guide portion is fixedly connected to the first hole wall surface, and is opposite to the first through hole, the first guide portion has a first guide surface facing the lower insulating member, the angle between the first guide surface and the shielding portion is not equal to 90 degrees, and the plane where the first guide surface is located intersects with the opening of the explosion-proof hole on the first surface.

[0010] Because the melting point of the bracket is greater than that of the lower insulating member, when the energy storage device experiences thermal runaway and the lower insulating member melts, the bracket does not deform. The high-temperature gas inside the energy storage device impacts the first guide portion from the gap between the shielding portion and the lower insulating member, and the high-temperature gas will be ejected from the explosion-proof hole in the direction of the first guide surface. At this time, the high-temperature gas will be ejected from the explosion-proof hole in a parabolic manner, which can not only eject carbonized debris, molten aluminum beads, and electrolyte carried by the high-temperature gas farther, but also prevent the carbonized debris, molten aluminum beads, and electrolyte from accumulating around the explosion-proof hole. Moreover, since the densities of carbonized debris, molten aluminum beads, and electrolyte vary, the ejection distances of substances with different densities will also be different. Therefore, substances with different densities will be stratified and will not accumulate together, which can further reduce the probability of fire, avoid fire when the energy storage device experiences thermal runaway, reduce safety hazards of the energy storage device, and improve the reliability of the energy storage device.

[0011] In addition, when the energy storage device is inverted or falls, if the electrolyte impacts the explosion-proof valve from the first through hole along the height direction of the energy storage device, the first guide portion will rebound the electrolyte and guide the electrolyte to a position away from the explosion-proof valve, thereby preventing the electrolyte from directly impacting the explosion-proof valve, causing the notch creep burst value of the explosion-proof valve to be unstable or even opening the valve, thereby ensuring the reliability of the energy storage device.

[0012] The angle between the first guide surface and the shielding portion is greater than or equal to 25 degrees and less than or equal to 85 degrees, so as to ensure that the first guide surface can guide the high-temperature gas to be ejected from the explosion-proof hole in a parabolic direction.

[0013] The angle between the first guide surface and the shielding portion is greater than or equal to 35 degrees and less than or equal to 55 degrees, so as to ensure that the first guide surface can guide the high-temperature gas to be ejected from the explosion-proof hole in a parabolic direction.

[0014] The first guide portion further has a second guide surface, which is arranged opposite to the first guide surface and has an angle with the shielding portion that is not equal to 90 degrees. The second guide surface intersects with the opening of the explosion-proof hole on the first surface.

[0015] When the energy storage device experiences thermal runaway and the lower insulating member melts, the bracket does not deform. The high-temperature gas inside the energy storage device impacts the first guide portion from the gap between the shielding portion and the lower insulating member. The high-temperature gas on one side will be ejected from the explosion-proof hole along the direction of the first guide surface, and the high-temperature gas on the other side will be affected by the airflow of the first through hole, and the airflow direction will rotate more than 90 degrees and eject from the explosion-proof hole along the direction of the second guide surface. At this time, the high-temperature gas will be ejected from the explosion-proof hole in a parabolic manner, which can not only remove the high-temperature gas The carbonized debris, molten aluminum beads, electrolyte and other substances carried by the device are sprayed farther, which can prevent the carbonized debris, molten aluminum beads, electrolyte and other substances from accumulating around the explosion-proof hole. Moreover, since the densities of carbonized debris, molten aluminum beads, electrolyte and other substances are different, the spraying distances of substances with different densities will also be different. Therefore, substances with different densities will be stratified and will not accumulate together, which can further reduce the probability of fire, avoid fire when the energy storage device has thermal runaway, reduce the safety hazards of the energy storage device, and improve the reliability of the energy storage device.

[0016] The explosion-proof hole has a center line, and along the length direction of the end cover assembly, the distance between the center line and the hole wall of the explosion-proof hole is W;

[0017] The first guide portion has a first fixed end face and a first free end face, the first fixed end face is fixedly connected to the first hole wall, the first free end face is arranged opposite to the first fixed end face, and is located on the side of the first fixed end face facing the center line, the first guide surface and the second guide surface are symmetrical about the center plane of the first guide portion, the intersection line of the plane where the center plane of the first guide portion is located and the opening of the explosion-proof hole on the first surface is the first intersection line, along the length direction of the end cover assembly, the distance between the first intersection point and the center line is S1, and the ratio of S1 to W is greater than or equal to 0 and less than or equal to 0.8, so as to ensure that when the energy storage device loses control, the gas guided by the first guide portion can be discharged from the explosion-proof hole.

[0018] The ratio of S1 to W is greater than or equal to 0 and less than or equal to 0.3, so as to ensure that when the energy storage device loses control, the gas guided by the first guide portion can be discharged from the explosion-proof hole.

[0019] The bracket includes a first mounting portion and a first connecting portion. Along the thickness direction of the end cap assembly, the first mounting portion is located on one side of the shielding portion and is spaced apart from the shielding portion. The first mounting portion has a first overlapping surface, which overlaps the lower insulating member. The first connecting portion is connected between the shielding portion and the first mounting portion.

[0020] The first guide portion has a first fixed end face and a first free end face, the first fixed end face is fixedly connected to the first hole wall surface, the first free end face is located on the side of the first lap face facing the first fixed end face, and the minimum distance between the first free end face and the first lap face in the thickness direction of the end cover assembly is greater than or equal to 1 mm and less than or equal to 2 mm to avoid interference between the first guide portion and the explosion-proof valve.

[0021] The shielding portion is further provided with a second through hole, the second through hole penetrating the shielding portion along the thickness direction of the shielding portion, the first through hole and the second through hole being spaced apart in the width direction of the end cover assembly, the second through hole having a third hole wall surface and a fourth hole wall surface, and the third hole wall surface and the fourth hole wall surface being spaced apart and opposite to each other in the length direction of the end cover assembly;

[0022] The bracket also includes a second guide portion, which is fixedly connected to the wall of the fourth hole and is arranged opposite to the second through hole. The second guide portion has a third guide surface facing the lower insulating member. The angle between the third guide surface and the shielding portion is not equal to 90 degrees, and the plane where the third guide surface is located intersects with the opening of the explosion-proof hole on the first surface.

[0023] When thermal runaway occurs in the energy storage device, the high-temperature gas inside the energy storage device impacts the second guide portion from the gap between the shielding portion and the lower insulating member. The high-temperature gas will be ejected from the explosion-proof hole in the direction of the third guide surface. At this time, the high-temperature gas will be ejected from the explosion-proof hole in a parabolic manner. This not only allows the carbonized debris, molten aluminum beads, and electrolyte carried by the high-temperature gas to be ejected farther, but also prevents the carbonized debris, molten aluminum beads, and electrolyte from accumulating around the explosion-proof hole. Moreover, since the density of the carbonized debris, molten aluminum beads, and electrolyte varies, the ejection distance of substances with different densities will also vary. Therefore, substances with different densities will be stratified and will not accumulate together, which can further reduce the probability of fire, avoid fire when the energy storage device experiences thermal runaway, reduce safety hazards of the energy storage device, and improve the reliability of the energy storage device.

[0024] In addition, when the energy storage device is inverted or falls, if the electrolyte impacts the explosion-proof valve from the second through hole along the height direction of the energy storage device, the second guide portion will rebound the electrolyte and guide the electrolyte to a position away from the explosion-proof valve, thereby preventing the electrolyte from directly impacting the explosion-proof valve, causing the notch creep burst value of the explosion-proof valve to be unstable or even opening the valve, thereby ensuring the reliability of the energy storage device.

[0025] The angle between the third guide surface and the shielding portion is greater than or equal to 25 degrees and less than or equal to 85 degrees, so as to ensure that the third guide surface can guide the high-temperature gas to be ejected from the explosion-proof hole in a parabolic direction.

[0026] The included angle between the third guide surface and the shielding portion is greater than or equal to 35 degrees and less than or equal to 55 degrees, so as to ensure that the third guide surface can guide the high-temperature gas to be ejected from the explosion-proof hole in a parabolic direction.

[0027] The second guide portion further has a fourth guide surface, which is arranged opposite to the third guide surface and has an angle with the shielding portion that is not equal to 90 degrees. The fourth guide surface intersects with the opening of the explosion-proof hole on the first surface.

[0028] When thermal runaway occurs in the energy storage device, high-temperature gas inside the energy storage device impacts the second guide portion through the gap between the shielding portion and the lower insulating member. The high-temperature gas on one side is affected by the airflow from the second through hole, causing the airflow direction to rotate more than 90 degrees and eject from the explosion-proof hole along the direction of the fourth guide surface. The high-temperature gas on the other side is ejected from the explosion-proof hole along the direction of the third guide surface. At this time, the high-temperature gas is ejected from the explosion-proof hole in a parabolic manner. This not only ejects carbonized debris, molten aluminum beads, and electrolyte carried by the high-temperature gas farther, thus preventing accumulation of carbonized debris, molten aluminum beads, and electrolyte around the explosion-proof hole, but also because the density of carbonized debris, molten aluminum beads, and electrolyte varies, the ejection distance of materials of different densities will also vary. Therefore, materials of different densities will be separated into layers and will not accumulate together. This can further reduce the probability of fire, avoid fire in the event of thermal runaway of the energy storage device, reduce safety hazards of the energy storage device, and improve the reliability of the energy storage device.

[0029] The explosion-proof hole has a center line, the inclination direction of the first guide portion relative to the baffle is a first direction, and the inclination direction of the second guide portion relative to the baffle is a second direction. The first direction and the second direction are symmetrically arranged about the center line to ensure that when thermal runaway occurs in the energy storage device, high-temperature gas can be discharged symmetrically from the explosion-proof hole, ensuring balanced force on the energy storage device, avoiding the energy storage device from tipping over due to uneven force, and ensuring the reliability of the energy storage device.

[0030] The explosion-proof hole has a center line, and along the length direction of the end cover assembly, the distance between the center line and the hole wall of the explosion-proof hole is W;

[0031] The second guide portion has a second fixed end face and a second free end face, the second fixed end face is fixedly connected to the second hole wall, the second free end face is arranged opposite to the second fixed end face, and is located on the side of the second fixed end face facing the center line, the third guide face and the fourth guide face are symmetrical about the center plane of the second guide portion, the intersection line of the plane where the center plane of the second guide portion is located and the opening of the explosion-proof hole on the first surface is the second intersection line, along the length direction of the end cover assembly, the distance between the second intersection line and the center line is S2, and the ratio of S2 to W is greater than or equal to 0 and less than or equal to 0.8, so as to ensure that when the energy storage device loses control, the gas guided by the second guide portion can be discharged from the explosion-proof hole.

[0032] Wherein, along the length direction of the end cover assembly, the first hole wall surface is located on the side of the fourth hole wall surface facing the third hole wall surface, and the fourth hole wall surface is located on the side of the first hole wall surface facing the second hole wall surface.

[0033] When thermal runaway occurs in the energy storage device, the high-temperature gas inside the energy storage device impacts the first guide part and the second guide part from the gap between the shielding part and the lower insulating part. The first guide part and the second guide part can both guide the high-temperature gas to be ejected from the explosion-proof hole. At this time, the high-temperature gas will be ejected from the explosion-proof hole in a parabolic manner, which can not only eject carbonized debris, molten aluminum beads, electrolyte and other substances carried by the high-temperature gas farther, but also prevent the carbonized debris, molten aluminum beads, electrolyte and other substances from accumulating around the explosion-proof hole. In addition, since the densities of carbonized debris, molten aluminum beads, electrolyte and other substances are different, the ejection distances of substances with different densities will also be different. Therefore, substances with different densities will be stratified and will not accumulate together, which can further reduce the probability of fire, avoid fire when the energy storage device suffers from thermal runaway, reduce the safety hazards of the energy storage device, and improve the reliability of the energy storage device.

[0034] Wherein, along the length direction of the end cover assembly, the first hole wall surface is located on the side of the fourth hole wall surface away from the third hole wall surface, and the fourth hole wall surface is located on the side of the first hole wall surface away from the second hole wall surface.

[0035] When thermal runaway occurs in the energy storage device, the high-temperature gas inside the energy storage device impacts the first guide part and the second guide part from the gap between the shielding part and the lower insulating part. The first guide part and the second guide part can both guide the high-temperature gas to be ejected from the explosion-proof hole. At this time, the high-temperature gas will be ejected from the explosion-proof hole in a parabolic manner, which can not only eject carbonized debris, molten aluminum beads, electrolyte and other substances carried by the high-temperature gas farther, but also prevent the carbonized debris, molten aluminum beads, electrolyte and other substances from accumulating around the explosion-proof hole. In addition, since the densities of carbonized debris, molten aluminum beads, electrolyte and other substances are different, the ejection distances of substances with different densities will also be different. Therefore, substances with different densities will be stratified and will not accumulate together, which can further reduce the probability of fire, avoid fire when the energy storage device suffers from thermal runaway, reduce the safety hazards of the energy storage device, and improve the reliability of the energy storage device.

[0036] Wherein, the bracket has a second overlapping surface, and the second overlapping surface is overlapped with the lower insulating member;

[0037] The second guide portion has a second fixed end face and a second free end face, the second fixed end face is fixedly connected to the second hole wall surface, the second free end face is located on the side of the second overlapping surface facing the second fixed end face, and the minimum distance between the second free end face and the second overlapping surface is greater than or equal to 1 mm and less than or equal to 2 mm to avoid interference between the second guide portion and the explosion-proof valve.

[0038] The bracket further includes a first mounting portion, a second mounting portion, a first connecting portion, and a second connecting 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 spaced apart from the shielding portion. 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.

[0039] The first mounting portion and the second mounting portion are fixedly mounted on the second surface to ensure assembly stability between the bracket and the end cover.

[0040] The bracket further includes a first mounting portion, a second mounting portion, a first connecting portion, and a second connecting 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 spaced apart from the shielding portion. 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.

[0041] The bracket is provided with a plurality of fixing holes, a portion of which is provided on the first mounting portion and passes through the first mounting portion along a thickness direction of the first mounting portion and is spaced apart from each other, and another portion of which is provided on the second mounting portion and passes through the second mounting portion along a thickness direction of the second mounting portion and is spaced apart from each other;

[0042] The lower insulating member is provided with a plurality of fixing parts, which are all provided on the side of the lower insulating member facing the end cover, and are passed through the corresponding fixing holes one by one, and are all fixedly connected to the bracket to ensure the assembly stability between the bracket and the lower insulating member.

[0043] In a second aspect, the present application provides an energy storage device, comprising a shell, a battery cell assembly and any one of the end cover assemblies described above, 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.

[0044] 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

[0045] 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.

[0046] Figure 1a is a structural diagram of an energy storage system according to an embodiment of the present application;

[0047] Figure 1b It is a structural schematic diagram of the energy storage device provided by this application;

[0048] Figure 2 yes Figure 1b A schematic structural diagram of the end cover assembly in the energy storage device shown;

[0049] Figure 3 yes Figure 2 The end cap assembly shown is a schematic structural diagram of the first embodiment after being cut along II;

[0050] Figure 4 yes Figure 2 The end cap assembly is shown as a schematic diagram of an exploded structure in a first embodiment;

[0051] Figure 5 yes Figure 4 A schematic structural diagram of the end cap in the end cap assembly shown;

[0052] Figure 6 yes Figure 4A schematic structural diagram of the lower insulating member in the end cap assembly shown;

[0053] Figure 7 yes Figure 4 A schematic diagram of the structure of the bracket in the end cover assembly shown;

[0054] Figure 8 yes Figure 7 A schematic structural diagram of the bracket shown at another angle;

[0055] Figure 9 yes Figure 4 A schematic diagram of the assembly structure of the end cap and the bracket in the end cap assembly shown;

[0056] Figure 10 yes Figure 4 A schematic diagram of the partial assembly structure of the end cap, lower insulating member and bracket in the end cap assembly shown;

[0057] Figure 11 yes Figure 10 The structure shown is a schematic diagram of the structure after being cut along II-II;

[0058] Figure 12 1 is a schematic diagram of the gas flow path when thermal runaway occurs in the energy storage device, wherein the energy storage device adopts the end cap assembly shown in the first embodiment;

[0059] Figure 13 is a schematic diagram of the electrolyte flow path when the energy storage device is inverted;

[0060] Figure 14 yes Figure 2 The schematic structural diagram of the lower insulating member of the end cap assembly in the second embodiment is shown;

[0061] Figure 15 yes Figure 2 The end cap assembly is a schematic structural diagram of a bracket in a second embodiment;

[0062] Figure 16 yes Figure 2 The end cap assembly is shown as a schematic diagram of the assembly structure of the lower insulating member and the bracket in the second embodiment;

[0063] Figure 17 yes Figure 16 The structure shown is a schematic diagram of the structure after being cut along III-III;

[0064] Figure 18 yes Figure 2 A schematic structural diagram of the lower insulating member of the end cap assembly in a third embodiment;

[0065] Figure 19 yes Figure 2A schematic diagram of the assembly structure of the lower insulating member and the bracket of the end cap assembly in the third embodiment is shown;

[0066] Figure 20 yes Figure 19 The structure shown is a schematic diagram of the structure after being cut along IV-IV;

[0067] Figure 21 yes Figure 2 The end cap assembly is a schematic structural diagram of the fourth embodiment after being cut along the lower edge II;

[0068] Figure 22 yes Figure 21 A schematic diagram of the structure of the bracket in the end cover assembly shown;

[0069] Figure 23 Figure 22 A schematic structural diagram of the bracket shown at another angle;

[0070] Figure 24 yes Figure 21 A schematic diagram of the partial assembly structure of the end cap, lower insulating member and bracket in the end cap assembly shown;

[0071] Figure 25 yes Figure 24 The structure shown is a schematic diagram of the structure after being cut along VV;

[0072] Figure 26 1 is a schematic diagram of the gas flow path when thermal runaway occurs in the energy storage device, wherein the energy storage device adopts the end cap assembly shown in the fourth embodiment;

[0073] Figure 27 yes Figure 2 The end cap assembly is a schematic structural diagram of the fifth embodiment after being cut along II;

[0074] Figure 28 yes Figure 27 A schematic diagram of the structure of the bracket in the end cover assembly shown;

[0075] Figure 29 Figure 28 A schematic structural diagram of the bracket shown at another angle;

[0076] Figure 30 yes Figure 27 A schematic diagram of the partial assembly structure of the end cap, lower insulating member and bracket in the end cap assembly shown;

[0077] Figure 31 yes Figure 30 The structure shown is a schematic diagram of the structure after being cut along VI-VI.

[0078] The names corresponding to the reference numerals in the figures are:

[0079] 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, upper insulator 60, pole 70, pressure ring 80, sealing ring 90, connecting piece 121, limiting column 122, first surface 101, second surface 102, explosion-proof hole 103, first mounting hole 104, first limiting hole 105, center line O, third surface 401, fourth surface 402, peripheral side surface 403, sub-peripheral side surface 4031, mounting groove 404, second mounting hole 405, through groove 4041, sub-mounting groove 4042, first groove side wall surface 404a, second groove side wall surface 404b, protrusion 41, protruding surface 411, shielding portion 51, second mounting portion 52, first mounting portion 53, Second connecting portion 54, first connecting portion 55, second air guide portion 56, first air guide portion 57, first side surface 511, second side surface 512, shielding surface 513, fifth surface 514, second through hole 515, first through hole 516, fourth hole wall surface 5151, third hole wall surface 5152, second hole wall surface 5161, first hole wall surface 5162, second overlapping surface 521, second mating surface 522, first overlapping surface 531, first A mating surface 532, a second fixed end surface 561, a second free end surface 562, a fourth guide surface 563, a third guide surface 564, a first fixed end surface 571, a first free end surface 572, a second guide surface 573, a first guide surface 574, a sixth surface 601, a seventh surface 602, a third mounting hole 603, an assembly groove 604, a second limiting hole 605, a third limiting hole 801, a fixing portion 43 and a fixing hole 501. DETAILED DESCRIPTION

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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:

[0085] (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.

[0086] (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;

[0087] (3) Small energy storage cabinets used on the power consumption side, whose main functions are self-generation and self-use of electricity, peak-valley price arbitrage, capacity cost management, and improving power supply reliability. According to different application scenarios, energy storage on the power consumption side 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 power market that implements peak-valley electricity prices, 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 electricity price arbitrage is achieved, reducing electricity costs. In addition, industrial enterprises that are subject to two-part electricity prices can use energy storage systems to store energy during low electricity consumption and discharge it during peak load, thereby reducing peak power and the maximum demand reported, and achieving the purpose of reducing capacity electricity charges. Household photovoltaic storage can improve the level of self-generation and self-use of electricity. Due to high electricity prices and poor power supply stability, the demand for household photovoltaic installation is driven. Considering that photovoltaic power generation occurs during the day, while user loads are generally higher at night, deploying energy storage can better utilize photovoltaic power, increasing self-generation and self-consumption while reducing electricity costs. Furthermore, energy storage is required for backup power in areas such as communication base stations and data centers.

[0088] In some embodiments, see Figure 1a , Figure 1a This is a schematic diagram of the structure of an energy storage system 400 according to an embodiment of the present application. Figure 1a The embodiment is described by taking the shared energy storage scenario on the power generation / distribution side as an example, but the energy storage device 100 of the present application is not limited to the energy storage scenario on the power generation / distribution side.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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. Optionally, when the energy storage device 100 is a single cell, 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. The single cell may be a secondary battery, which refers to a battery that can continue to be used by recharging the active material 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 restrictions 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 products listed, and may also be other application forms. The present application does not impose strict restrictions on the application form of the energy storage device 100. The present application uses the energy storage device 100 as a square battery as an example for explanation.

[0097] 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.

[0098] 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.

[0099] 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, an upper insulator 60, a pole 70, a pressure ring 80, a sealing ring 90, a connecting sheet 121 and a limiting column 122. The explosion-proof valve 20 and the protective sheet 30 are both installed on the end cap 10. Along the thickness direction of the end cap 10, the lower insulator 40 and the bracket 50 are located on the same side of the end cap 10. The upper insulator 60 is installed on the side of the end cap 10 away from the lower insulator 40. There are two upper insulators 60. Along the length direction of the end cap assembly 120, the two upper insulators 60 are arranged at intervals. One upper insulator 60 is used as the positive pole upper insulator, and the other upper insulator 60 is used as the negative pole upper insulator.

[0100] Along the thickness direction of the end cap assembly 120, the pole 70 passes through the end cap 10, the lower insulator 40, and the upper insulator 60. There are two poles 70. One pole 70 serves as the positive pole and passes through the end cap 10, the lower insulator 40, and the positive upper insulator. The other pole 70 serves as the negative pole and passes through the end cap 10, the lower insulator 40, and the negative upper insulator. The pressure ring 80 is mounted on the upper insulator 60, sleeved on the pole 70, and fixedly connected to the pole 70. There are two pressure rings 80. One pressure ring 80 serves as the positive pole pressure ring, which is mounted on the positive upper insulator, sleeved on the positive pole pole, and fixedly connected to the positive pole pole. The other pressure ring 80 serves as the negative pole pressure ring, which is mounted on the negative upper insulator, sleeved on the negative pole pole, and fixedly connected to the negative pole pole.

[0101] A sealing ring 90 is mounted on the electrode post 70 and is clamped between the end cap 10 and the electrode post 70. There are two sealing rings 90. One sealing ring 90 serves as a positive electrode sealing ring and is mounted on the positive electrode post and is clamped between the end cap 10 and the positive electrode post. The other sealing ring 90 serves as a negative electrode sealing ring and is mounted on the negative electrode post and is clamped between the end cap 10 and the negative electrode post.

[0102] The connecting tab 121 is located on the side of the lower insulator 40 facing away from the end cap 10 and is fixedly connected to the electrode post 70 and the tab of the battery cell assembly. There are two connecting tabs 121. One connecting tab 121 serves as the positive electrode connecting tab and is fixedly connected to the positive electrode post and the positive tab of the battery cell assembly. The other connecting tab 121 serves as the negative electrode connecting tab and is fixedly connected to the negative electrode post and the negative tab of the battery cell assembly.

[0103] Along the thickness direction of the end cover assembly 120, the limiting posts 122 pass through the upper insulating member 60 and abut between the end cover 10 and the pressure ring 80. There are multiple limiting posts 122. A portion of the limiting posts 122 pass through the positive upper insulating member and abut between the end cover 10 and the positive pressure ring, and are spaced around the positive pole. Another portion of the limiting posts 122 pass through the negative upper insulating member and abut between the end cover 10 and the negative pressure ring, and are spaced around the negative pole. Exemplarily, there are six limiting posts 122. Three limiting posts 122 pass through the positive insulating member and abut between the end cover 10 and the positive pressure ring, and are spaced around the positive pole. Three limiting posts 122 pass through the negative insulating member and abut between the end cover 10 and the negative pressure ring, and are spaced around the negative pole.

[0104] See also Figure 5 , Figure 5 yes Figure 4 A schematic structural diagram of the end cover 10 in the end cover assembly 120 is shown.

[0105] The end cover 10 has a first surface 101 and a second surface 102. The first surface 101 and the second surface 102 are oppositely arranged along the thickness direction (the Z-axis direction shown in the figure) of the end cover 10. The end cover 10 is provided with an explosion-proof hole 103, a first mounting hole 104, and a first limiting hole 105. The explosion-proof hole 103 and the first mounting hole 104 both penetrate the first surface 101 and the second surface 102. Specifically, along the length direction (the X-axis direction shown in the figure) of the end cover 10, the explosion-proof hole 103 is located in the middle of the end cover 10. The explosion-proof hole 103 has a center line O, and the distance between the center line O and the hole wall surface of the explosion-proof hole 103 along the length direction (the X-axis direction shown in the figure) of the end cover 10 is W.

[0106] The first mounting hole 104 has two. Along the length direction of the end cover 10, the two first mounting holes 104 are respectively located on the opposite sides of the explosion-proof hole 103 and are both arranged at intervals from the explosion-proof hole 103. The first limiting hole 105 has an opening on the first surface 101. The first limiting hole 105 is recessed from the first surface 101 to the second surface 102 (the negative direction of the Z-axis shown in the figure) and is arranged at intervals from the first mounting hole 104. Among them, the first limiting hole 105 has a plurality, a part of the first limiting hole 105 is arranged at intervals around one first mounting hole 104, and another part of the first limiting hole 105 is arranged at intervals around the other first mounting hole 104. For example, the first limiting hole 105 has six, and every three first limiting holes 105 are evenly arranged around one first mounting hole 104.

[0107] Please refer to Figure 3 , the explosion-proof valve 20 covers the opening of the explosion-proof hole 103 on the second surface 102. When the energy storage device 100 occurs thermal runaway, the explosion-proof valve 20 will be opened, and the high-temperature gas inside the energy storage device 100 will be sprayed out from the explosion-proof hole 103, so as to avoid the explosion of the energy storage device 100 and ensure the use reliability of the energy storage device 100. Among them, the length direction of the explosion-proof valve 20 is parallel to the width direction (the Y-axis direction shown in the figure) of the end cover 10. The protective sheet 30 covers the opening of the explosion-proof hole 103 on the first surface 101 to protect the explosion-proof valve 20.

[0108] Please refer to Figure 6 , Figure 6 is Figure 4 the structure diagram of the lower insulating piece 40 in the end cover assembly 120 shown in

[0109] The lower insulating member 40 has a third surface 401, a fourth surface 402, and a peripheral side surface 403. Along the thickness direction of the lower insulating member 40 (the Z-axis direction in the figure), the third surface 401 and the fourth surface 402 are disposed opposite each other. The peripheral side surface 403 is connected between the third surface 401 and the fourth surface 402. The peripheral side surface 403 includes two sub-peripheral side surfaces 4031. Along the width direction of the lower insulating member 40 (the Y-axis direction in the figure), the two sub-peripheral side surfaces 4031 are disposed opposite each other.

[0110] The lower insulator 40 is provided with a mounting slot 404 and a second mounting hole 405. The opening of the mounting slot 404 is located on the third surface 401. The mounting slot 404 is recessed from the third surface 401 toward the fourth 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.

[0111] In this embodiment, the mounting groove 404 includes a through groove 4041 and two sub-mounting grooves 4042. Along the length direction of the mounting groove 404, the through groove 4041 is located in the middle of the mounting groove 404 and passes through the third surface 401 and the fourth surface 402. The through groove 4041 has a first groove side wall surface 404a and a second groove side wall surface 404b. Along the length direction of the end cover assembly 120, the first groove side wall surface 404a and the second groove side wall surface 404b are spaced apart and arranged opposite to each other. Along the length direction of the mounting groove 404, the two sub-mounting grooves 4042 are respectively located on opposite sides of the through groove 4041, and are both connected to the through groove 4041 and pass through the peripheral side surface 403. Each sub-mounting groove 4042 passes through a sub-peripheral side surface 4031.

[0112] The second mounting holes 405 extend through the third surface 401 and the fourth surface 402. There are two first mounting holes. Along the length of the lower insulator 40, the two second mounting holes 405 are located on opposite sides of the mounting slot 404 and are spaced apart from the mounting slot 404.

[0113] The lower insulating member 40 is provided with two protrusions 41. Both protrusions 41 are provided on the fourth surface 402, and both protrude from the fourth surface 402 in a direction away from the third surface 401 (the negative direction of the Z axis in the figure), and are used to abut 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. Along the length direction of the lower insulating member 40, the two protrusions 41 are both located in the middle of the lower insulating member 40. Along the width direction of the lower insulating member 40, the two protrusions 41 are respectively located on opposite sides of the through groove 4041. Each protrusion 41 is provided corresponding to a sub-mounting groove 4042.

[0114] See also Figure 7 and Figure 8 , Figure 7 yes Figure 4 The schematic structural diagram of the bracket 50 in the end cover assembly 120 is shown. Figure 8 yes Figure 7 The structure diagram of the bracket 50 shown in another angle is shown, wherein 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.

[0115] 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, such as metals or inorganic materials such as ceramics. The bracket 50 is shaped like a Chinese character "几". For example, the bracket 50 can be formed by bending a coil.

[0116] The bracket 50 includes a shielding portion 51, a first mounting portion 53, a second mounting portion 52, a first connecting portion 55, a second connecting portion 54, a first air guide portion 57, and a second air guide portion 56. Along the thickness direction of the bracket 50, the first mounting portion 53 and the second mounting portion 52 are located on one side of the shielding portion 51 and are spaced apart from the shielding portion 51. The first connecting portion 55 is fixedly connected between the shielding portion 51 and the first mounting portion 53. The second connecting portion 54 is fixedly connected between the shielding portion 51 and the second mounting portion 52. The first air guide portion 57 and the second air guide portion 56 are both fixedly connected to the shielding portion 51. The shielding portion 51, the first mounting portion 53, the second mounting portion 52, the first connecting portion 55, the second connecting portion 54, the first air guide portion 57, and the second air guide portion 56 can be integrally formed.

[0117] 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 has a first side surface 511, a second side surface 512, a shielding surface 513 and a fifth surface 514. Along the width direction of the bracket 50, the first side surface 511 and the second side surface 512 are arranged back to back. Along the thickness direction of the bracket 50, the shielding surface 513 and the fifth surface 514 are arranged back to back and are both connected between the first side surface 511 and the second side surface 512. An insulating film (not shown) is provided on the shielding surface 513. 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 any specific restrictions on this.

[0118] The shielding portion 51 is provided with a first through hole 516 and a second through hole 515. The first through hole 516 and the second through hole 515 both penetrate the shielding portion 51 along the thickness direction of the shielding portion 51 (Z-axis direction in the figure) and are spaced apart from each other. Along the length direction of the bracket 50, the first through hole 516 and the second through hole 515 are spaced apart. The first through hole 516 has a first hole wall surface 5162 and a second hole wall surface 5161. The second through hole 515 has a third hole wall surface 5152 and a fourth hole wall surface 5151. Along the width direction of the bracket 50, the first hole wall surface 5162 and the second hole wall surface 5161 are spaced apart and arranged opposite to each other, and the third hole wall surface 5152 and the fourth hole wall surface 5151 are spaced apart and arranged opposite to each other. Among them, the first hole wall surface 5162 is located on the side of the second hole wall surface 5161 facing the second side surface 512, and the third hole wall surface 5152 is located on the side of the fourth hole wall surface 5151 facing the second side surface 512.

[0119] In this embodiment, the second through hole 515 and the first through hole 516 partially overlap along the width direction of the bracket 50. Specifically, along the width direction of the bracket 50, the fourth hole wall surface 5151 is located on the side of the first hole wall surface 5162 facing the second hole wall surface 5161 and is spaced apart from the first hole wall surface 5162. The first hole wall surface 5162 is located on the side of the fourth hole wall surface 5151 facing the third hole wall surface 5152 and is spaced apart from the fourth hole wall surface 5151.

[0120] Along the length of the bracket 50, the first mounting portion 53 and the second mounting portion 52 are located on opposite sides of the shielding portion 51. Specifically, the first mounting portion 53 and the second mounting portion 52 are both located on the side of the fifth surface 514 away from the shielding surface 513, and are both spaced apart from the fifth surface 514. Along the length of the bracket 50, the second mounting portion 52 is located on the side of the second through hole 515 away from the first through hole 516, and the first mounting portion 53 is located on the side of the first through hole 516 away from the second through hole 515.

[0121] In this embodiment, the second mounting portion 52 has a second overlapping surface 521 and a second mating surface 522, and the first mounting portion 53 has a first overlapping surface 531 and a first mating surface 532. Along the thickness direction of the bracket 50, the second overlapping surface 521 and the second mating surface 522 are disposed opposite each other, and the first overlapping surface 531 and the first mating surface 532 are disposed opposite each other. The first overlapping surface 531 and the second overlapping surface 521 face the same direction and are flush with the first overlapping surface 531. The first mating surface 532 and the second mating surface 522 face the same direction and are flush with the first mating surface 532.

[0122] The second connecting portion 54 and the second mounting portion 52 are located on the same side of the shielding portion 51 along the length direction of the bracket 50, and the first connecting portion 55 and the first mounting portion 53 are located on the same side of the shielding portion 51 along the length direction of the bracket 50. The second connecting portion 54 is located between the shielding portion 51 and the second mounting portion 52 along the thickness direction of the bracket 50, and the first connecting portion 55 is located between the shielding portion 51 and the first mounting portion 53 along the thickness direction of the bracket 50. The first connecting portion 55 and the second connecting portion 54 are both folded relative to the shielding portion 51, and the included angle between the first connecting portion 55 and the shielding portion 51 is greater than 0 degrees and less than 180 degrees. For example, the included angle between the first connecting portion 55 and the shielding portion 51 is 90 degrees.

[0123] In addition, the second connecting portion 54 is also folded relative to the second mounting portion 52, and the included angle between the second connecting portion 54 and the second mounting portion 52 is greater than 0 degrees and less than 180 degrees. The first connecting portion 55 is also folded relative to the first mounting portion 53, and the included angle between the first connecting portion 55 and the first mounting portion 53 is greater than 0 degrees and less than 180 degrees. For example, the included angle between the second connecting portion 54 and the second mounting portion 52 is 90 degrees, and the included angle between the first connecting portion 55 and the first mounting portion 53 is 90 degrees.

[0124] The second flow guide portion 56 is fixedly connected to the fourth hole wall surface 5151 and inclined relative to the shielding portion 51. The inclination direction of the second flow guide portion 56 relative to the shielding portion 51 is the second direction D2. Specifically, the second flow guide portion 56 has a second fixed end surface 561, a second free end surface 562, a fourth flow guide surface 563, and a third flow guide surface 564. The second fixed end surface 561 is fixedly connected to the fourth hole wall surface 5151. The second free end surface 562 is arranged opposite to the second fixed end surface 561 and opposite to the second through hole 515. The second free end surface 562 is located on the side of the second lap surface 521 facing the second fixed end surface 561 and is spaced apart from the second lap surface 521. The minimum distance between the second free end surface 562 and the second lap surface 521 along the thickness direction of the bracket 50 is greater than or equal to 1 millimeter and less than or equal to 2 millimeters, so as to avoid interference between the second flow guide portion 56 and the lower insulating piece 40. The fourth flow guide surface 563 faces the second through hole 515. The third flow guide surface 564 is arranged opposite to the fourth flow guide surface 563 and connected between the second fixed end surface 561 and the second free end surface 562. The third flow guide surface 564 and the fourth flow guide surface 563 are symmetric about the center surface of the second flow guide portion 56.

[0125] In this embodiment, the angle between the second guide portion 56 and the shielding portion 51 is not equal to 90 degrees. The angles between the fourth guide surface 563 and the third guide surface 564 and the shielding portion 51 are not equal to 90 degrees. Specifically, the angle between the second guide portion 56 and the shielding portion 51 is greater than or equal to 35 degrees and less than or equal to 55 degrees. The angles between the fourth guide surface 563 and the third guide surface 564 and the shielding portion 51 are both greater than or equal to 35 degrees and less than or equal to 55 degrees. In the event of thermal runaway of the energy storage device 100, the fourth guide surface 563 and the third guide surface 564 can guide the high-temperature gas to be ejected in a parabolic trajectory. In other embodiments, the angle between the second guide portion 56 and the shielding portion 51 can also be greater than or equal to 25 degrees and less than or equal to 85 degrees. In this case, the angles between the fourth guide surface 563 and the third guide surface 564 and the shielding portion 51 are both greater than or equal to 25 degrees and less than or equal to 85 degrees.

[0126] The first guide portion 57 is fixedly connected to the first hole wall 5162 and is inclined relative to the shielding portion 51. The inclination direction of the first guide portion 57 relative to the shielding portion 51 is the first direction D1, and the first direction D1 is symmetrically arranged with the second direction D2. Specifically, the first guide portion 57 has a first fixed end face 571, a first free end face 572, a second guide face 573 and a first guide face 574. The first fixed end face 571 is fixedly connected to the first hole wall 5162. The first free end face 572 is arranged opposite to the first fixed end face 571 and is arranged opposite to the first through hole 516. The first free end face 572 is located on the side of the first lap face 531 facing the first fixed end face 571 and is spaced apart from the first lap face 531. The minimum distance between the first free end surface 572 and the first overlapping surface 531 along the thickness direction of the bracket 50 is greater than or equal to 1 mm and less than or equal to 2 mm to prevent interference between the first guide portion 57 and the lower insulating member 40. The second guide surface 573 faces the first through-hole 516. The first guide surface 574 and the second guide surface 573 are disposed opposite each other and are both connected between the first fixed end surface 571 and the first free end surface 572. The first guide surface 574 and the second guide surface 573 are symmetrical about the center plane of the first guide portion 57.

[0127] In this embodiment, the angle between the first guide portion 57 and the shielding portion 51 is not equal to 90 degrees. The angles between the second guide surface 573 and the first guide surface 574 and the shielding portion 51 are not equal to 90 degrees. Specifically, the angle between the first guide portion 57 and the shielding portion 51 is greater than or equal to 35 degrees and less than or equal to 55 degrees. The angles between the second guide surface 573 and the first guide surface 574 and the shielding portion 51 are both greater than or equal to 35 degrees and less than or equal to 55 degrees. In the event of thermal runaway of the energy storage device 100, the second guide surface 573 and the first guide surface 574 can guide the high-temperature gas to be ejected in a parabolic trajectory. In other embodiments, the angle between the first guide portion 57 and the shielding portion 51 can also be greater than or equal to 25 degrees and less than or equal to 85 degrees. In this case, the angles between the second guide surface 573 and the first guide surface 574 and the shielding portion 51 are both greater than or equal to 25 degrees and less than or equal to 85 degrees.

[0128] It should be noted that, in some other embodiments, the shielding portion 51 may also be provided with more than two first through holes 516. In this case, the bracket 50 may also include more than two first guide portions 57, each first guide portion 57 is fixedly connected to the second hole wall 5161 of a first through hole 516, and / or, the shielding portion 51 may also be provided with more than two second through holes 515. In this case, the bracket 50 may also include more than two second guide portions 56, each second guide portion 56 is fixedly connected to the third hole wall 5152 of a second through hole 515. This application does not impose any specific restrictions on this.

[0129] Please also refer to Figure 9 , Figure 9 yes Figure 4 A schematic diagram of the assembly structure of the end cover 10 and the bracket 50 in the end cover assembly 120 is shown.

[0130] The bracket 50 is fixedly mounted on the second surface 102 of the end cap 10. Specifically, the first mounting portion 53 and the second mounting portion 52 are both fixedly mounted on the second surface 102. For example, the first mounting portion 53 and the second mounting portion 52 can be fixed to the second surface 102 by resistance spot welding. In this case, a recessed weld mark may be formed on the first overlapping surface 531 and the second overlapping surface 521. The shielding portion 51, the first air guide portion 57, and the second air guide portion 56 are disposed opposite the explosion-proof hole 103, and are symmetrically arranged in the first direction D1 and the second direction D2 about the centerline O of the explosion-proof hole 103. The plane containing the center plane (C) of the first air guide portion 57 and the plane containing the center plane of the second air guide portion 56 both intersect with the opening of the explosion-proof hole 103 on the first surface 101. Along the width of the end cap assembly 120, the second mounting portion 52 and the second connecting portion 54 are located on one side of the explosion-proof hole 103, while the first mounting portion 53 and the first connecting portion 55 are located on the other side of the explosion-proof hole 103.

[0131] Please refer to Figure 10 and Figure 11 , Figure 10 is Figure 4 the assembled partial structure diagram of the end cover 10, the lower insulating piece 40 and the bracket 50 in the end cover assembly 120 shown in FIG. 1, Figure 11 is Figure 10 the structure diagram of the structure shown in FIG. 1 after being cut along II-II.

[0132] The lower insulating piece 40 is located on the side of the second surface 102 away from the first surface 101. Among them, the third surface 401 is oppositely arranged with the second surface 102. The through slot 4041 of the mounting slot 404 is oppositely arranged with the explosion-proof hole 103. Two second mounting holes 405 are respectively communicated with two first mounting holes 104.

[0133] The bracket 50 is arranged in the through slot 4041. Specifically, the shielding part 51 is located on the side of the fourth surface 402 away from the third surface 401, and is located between the two protrusions 41 and is spaced and oppositely arranged with the through slot 4041. The normal projection of the explosion-proof valve 20 on the bracket 50 covers at least part of the shielding part 51. Among them, the first side surface 511 faces the first slot side wall surface 404a, the second side surface 512 faces the second slot side wall surface 404b, the shielding surface 513 faces away from the fourth surface 402, and has the same direction as the protruding surface 411. Illustratively, the shielding surface 513 is flush with the protruding surface 411, and abuts against the battery cell assembly to avoid the battery cell assembly from shaking inside the energy storage device 100, and ensure the structural stability of the energy storage device 100.

[0134] Since the shielding surface 513 is provided with an insulating film, the insulating film can avoid the shielding part 51 from directly contacting the battery cell assembly to cause short circuit, and ensure the use reliability of the energy storage device 100. Moreover, when the energy storage device 100 occurs thermal runaway, after the separator in the battery cell assembly melts, the gap between the cathode diaphragm and the anode diaphragm in the battery cell assembly and the shielding part 51 is small, which is easy to cause electrical breakdown and produce electric arc. The electric arc can ignite the combustible material. The design of the insulating film can also avoid the electrical breakdown between the shielding part 51 and the cathode diaphragm and the anode diaphragm, and can improve the use safety of the energy storage device 100.

[0135] The first mounting portion 53 and the second mounting portion 52 are both overlapped on the lower insulating member 40. Specifically, the first mounting portion 53 and the second mounting portion 52 are respectively located in the two first sub-mounting grooves 4042 and cover the two protrusions 41 respectively. The first mounting portion 53 and the second mounting portion 52 are respectively overlapped on the bottom wall surfaces of the two first sub-mounting grooves 4042. The first overlapping surface 531 and the second overlapping surface 521 are respectively overlapped on the bottom wall surfaces of the first sub-mounting grooves 4042. The first mating surface 532 and the second mating surface 522 can be flush with the third surface 401, or be located on the side of the third surface 401 facing the fourth surface 402. That is, the bracket 50 does not protrude relative to the third surface 401, which can ensure the assembly stability between the end cover 10 and the lower insulating member 40, and help to improve the structural stability of the end cover assembly 120.

[0136] The first connecting portion 55 and the second connecting portion 54 are both disposed through the through-slot 4041. The first guide portion 57 and the second guide portion 56 are both located on the side of the explosion-proof valve 20 facing the lower insulator 40. Specifically, the first guide portion 57 and the second guide portion 56 are both located on the side of the fourth surface 402 facing away from the third surface 401, and are located between the two protrusions 41, and are spaced apart from and opposite to the through-slot 4041. The second free end surface 562 is located on the side of the second fixed end surface 561 facing the centerline O of the explosion-proof hole 103, the third guide surface 564 faces the lower insulator 40, and the first free end surface 572 is located on the side of the first fixed end surface 571 facing the centerline O of the explosion-proof hole 103, and the first guide surface 574 faces the lower insulator 40. In addition, the planes of the first guide surface 574, the second guide surface 573, the third guide surface 564, and the fourth guide surface 563 all intersect with the opening of the explosion-proof hole 103 on the first surface 101. In other embodiments, at least one of the planes of the first guide surface 574, the second guide surface 573, the third guide surface 564, and the fourth guide surface 563 intersects with the opening of the explosion-proof hole 103 on the first surface 101.

[0137] It can be understood that since the second free end face 562 is located on the side of the second lap surface 521 away from the second mating surface 522 and is spaced apart from the second mating surface 522, the first free end face 572 is located on the side of the first lap surface 531 away from the first mating surface 532 and is spaced apart from the first lap surface 531, neither the first guide portion 57 nor the second guide portion 56 will extend into the explosion-proof hole 103 and interfere with the explosion-proof valve 20, thereby ensuring the reliability of the end cover assembly 120.

[0138] In addition, the intersection line of the plane containing the center plane of the second flow guide 56 and the opening of the explosion-proof hole 103 on the first surface 101 is a second intersection line (not shown), and the intersection line of the plane containing the center plane C of the first flow guide 57 and the opening of the explosion-proof hole 103 on the first surface 101 is a first intersection line D. The first intersection line D and the second intersection line are both parallel to the width direction of the end cap assembly 120. Along the length direction of the end cap assembly 120, the distance between the first intersection line D and the center line O of the explosion-proof hole 103 is S1, and the distance between the second intersection line and the center line O of the explosion-proof hole 103 is S2. The ratio of S1 to W is greater than or equal to 0 and less than or equal to 0.3, and the ratio of S2 to W is greater than or equal to 0 and less than or equal to 0.3. This ensures that when the energy storage device 100 loses control, the gas guided by the first flow guide 57 and the second flow guide 56 can be discharged from the explosion-proof hole 103. In some other embodiments, the ratio of S1 to W may also be greater than or equal to 0 and less than or equal to 0.8, and / or the ratio of S2 to W may also be greater than or equal to 0 and less than or equal to 0.8.

[0139] It should be noted that the center plane of the second air guide portion 56 is the center plane of the second air guide portion 56 in the thickness direction, and the portions of the second air guide portion 56 located on opposite sides of the center plane are symmetrical along the thickness direction. Similarly, the center plane of the first air guide portion 57 is the center plane of the first air guide portion 57 in the thickness direction, and the portions of the first air guide portion 57 located on opposite sides of the center plane are symmetrical along the thickness direction.

[0140] Please also refer to Figure 12 , Figure 12 Schematic diagram of the gas flow path when thermal runaway occurs in the energy storage device 100, wherein the energy storage device 100 adopts the end cap assembly 120 shown in the first embodiment. It should be noted that, Figure 12 The dashed line with an arrow is the flow path of the gas.

[0141] When thermal runaway occurs in the energy storage device 100, the explosion-proof valve 20 opens first. Reactions continue within the battery cell assembly, causing the temperature within the energy storage device 100 to rise continuously. Not only does the lower insulator 40 melt under the high temperature, forming carbonized debris, but the positive electrode foil within the battery cell assembly also melts under the high temperature, forming molten aluminum beads. Both the carbonized debris and the molten aluminum beads are ejected from the explosion-proof hole 103 along with the high-temperature gas. Because the molten aluminum beads reach temperatures as high as 600°C, they are highly susceptible to ignition upon contact with the carbonized debris. At this point, the high-temperature gas within the energy storage device 100 primarily separates into left-hand and right-hand high-temperature gas. The left-hand high-temperature gas flows from the gap between the first side surface 511 and the first slot sidewall 404a toward the through-slot 4041, while the right-hand high-temperature gas flows from the gap between the second side surface 512 and the second slot sidewall 404b toward the through-slot 4041. Both streams of gas then eject from the explosion-proof hole 103.

[0142] In this embodiment, since the melting point of the bracket 50 is greater than the melting point of the lower insulating member 40, the energy storage device 100 undergoes thermal runaway. When the lower insulating member 40 melts, the bracket 50 does not deform. The high-temperature gas on the left side impacts the third guide surface 564 of the second guide portion 56 and the second guide surface 573 of the first guide portion 57 from the gap between the first side surface 511 and the first groove side wall surface 404a. A portion of the high-temperature gas on the left side will be ejected from the explosion-proof hole 103 along the direction of the third guide surface 564. When another portion of the high-temperature gas on the left side impacts the second guide surface 573, it is affected by the airflow of the first through hole 516, and the airflow direction will rotate more than 90 degrees and be ejected from the explosion-proof hole 103 along the direction of the second guide surface 573. The high-temperature gas on the right side impacts the fourth guide surface 563 of the second guide portion 56 and the first guide surface 574 of the first guide portion 57 from the gap between the second side surface 512 and the second groove side wall surface 404b. A portion of the high-temperature gas on the right side impacts the fourth guide surface 563 of the second guide portion 56 and the first guide surface 574 of the first guide portion 57. When the fourth guide surface 563 is affected by the airflow from the second through hole 515, the airflow direction will rotate more than 90 degrees and be ejected from the explosion-proof hole 103 along the direction of the fourth guide surface 563. Another portion of the high-temperature gas on the right side will be ejected from the explosion-proof hole 103 along the direction of the first guide surface 574. At this time, the high-temperature gas will be ejected from the explosion-proof hole 103 in a parabolic manner. This not only can the carbonized debris, molten aluminum beads, and electrolyte carried by the high-temperature gas be ejected farther, thereby preventing the carbonized debris, molten aluminum beads, and electrolyte from accumulating around the explosion-proof hole 103, but also because 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 be separated into layers and will not accumulate together, which can further reduce the probability of fire, avoid fire when the energy storage device 100 suffers from thermal runaway, reduce safety hazards of the energy storage device 100, and improve the reliability of the energy storage device 100.

[0143] In addition, since the first direction D1 and the second direction D2 are symmetrically arranged, when the energy storage device 100 is in thermal runaway, the high-temperature gas is symmetrically sprayed from the explosion-proof hole 103, so that the stress balance of the energy storage device 100 can be ensured, and the energy storage device 100 is prevented from tilting due to unbalanced stress, and the use reliability of the energy storage device 100 is ensured.

[0144] Please refer to Figure 13 , Figure 13 is a schematic diagram of the flow path of the electrolyte when the energy storage device 100 is inverted. Among them, Figure 13 The dashed line with an arrow in the figure is the flow path of the electrolyte.

[0145] Since the shielding part 51 is only provided with the second through hole 515 and the first through hole 516, when the energy storage device 100 is inverted or dropped, if the electrolyte impacts the explosion-proof valve 20 along the height direction of the energy storage device 100 from the second through hole 515 and the first through hole 516, the fourth flow guide surface 563 and the second flow guide surface 573 will bounce the electrolyte to guide the electrolyte to a position away from the explosion-proof valve 20, avoiding the electrolyte directly impacting the explosion-proof valve 20, causing the indentation creep burst value of the explosion-proof valve 20 to be unstable or even open the valve, and ensuring the use reliability of the energy storage device 100.

[0146] Please refer to Figure 3 and Figure 4 Each upper insulating piece 60 is installed on the side of the first surface 101 away from the second surface 102. Each upper insulating piece 60 has a sixth surface 601 and a seventh surface 602. The sixth surface 601 is the surface of the upper insulating piece 60 away from the end cover 10. Along the thickness direction (the direction of the Z axis shown in the figure) of the upper insulating piece 60, the seventh surface 602 is arranged away from the sixth surface 601. That is, the seventh surface 602 is the surface of the upper insulating piece 60 towards the end cover 10.

[0147] Each upper insulating piece 60 is provided with a third mounting hole 603, an assembly groove 604, and a second limiting hole 605. The third mounting hole 603 penetrates the upper insulating piece 60 along the thickness direction of the upper insulating piece 60 and communicates with the first mounting hole 104. That is, the third mounting hole 603 penetrates the sixth surface 601 and the seventh surface 602. The opening of the assembly groove 604 is located on the sixth surface 601. The assembly groove 604 is recessed from the sixth surface 601 to the seventh surface 602 (the negative direction of the Z axis shown in the figure). The assembly groove 604 is arranged around the third mounting hole 603 and communicates with the third mounting hole 603.

[0148] In this embodiment, the second limiting hole 605 is a through hole. The second limiting hole 605 passes through the bottom wall surface (not shown) of the assembly slot 604 and the seventh surface 602, and is spaced apart from the third mounting hole 603 and communicates with the first limiting hole 105. There are multiple second limiting holes 605, and the multiple second limiting holes 605 are spaced apart around the third mounting hole 603 and communicate with the multiple first limiting holes 105 in a one-to-one correspondence. Exemplarily, there are three second limiting holes 605, and the three second limiting holes 605 are evenly spaced apart around the third mounting hole 603.

[0149] Each pole 70 is penetrated by the corresponding first mounting hole 104, the corresponding second mounting hole 405 and the corresponding third mounting hole 603. Each pressure ring 80 is installed in the assembly groove 604 of the corresponding upper insulating member 60. Each pressure ring 80 is provided with a third limiting hole 801. The third limiting hole 801 is a blind hole. The opening of the third limiting hole 801 is located on the surface of the bottom wall of the pressure ring 80 facing the assembly groove 604. Among them, there are multiple third limiting holes 801, and the multiple third limiting holes 801 are arranged at intervals around the pole 70, and are connected to the multiple second limiting holes 605 in a one-to-one correspondence. Exemplarily, there are six third limiting holes 801, and the six third limiting holes 801 are evenly spaced and arranged around the pole 70.

[0150] Each sealing ring 90 is inserted into the corresponding second mounting hole 405 and the corresponding first mounting hole 104, and is clamped between the circumference of the pole 70 and the wall surface of the first mounting hole 104 in the radial direction of the pole 70. This not only prevents the pole 70 from contacting the end cover 10 and causing a short circuit, but also seals the gap between the pole 70 and the end cover 10, thereby ensuring the sealing reliability of the end cover assembly 120.

[0151] The limiting posts 122 are respectively provided in the second limiting holes 605 of the upper insulating member 60 in a one-to-one correspondence, one end of the limiting post 122 is inserted into the corresponding first limiting hole 105, and the other end is inserted into the corresponding third limiting hole 801. For example, the limiting post 122 can be a ceramic post made of ceramic. The design of the limiting post 122 can not only increase the assembly stability of the end cover assembly 120, but also improve the torsional strength of the pole 70 and improve the reliability of the energy storage device 100. It should be understood that the number of limiting posts 122 is not limited to Figure 4 The six limit posts 122 shown may also be less than five or more than seven, and this application does not impose any specific limitation on this.

[0152] See also Figure 14 , Figure 14 yes Figure 2 The end cap assembly 120 is a schematic structural diagram of the lower insulating member 40 in the second embodiment.

[0153] The end cap assembly 120 shown in this embodiment differs from the first end cap assembly 120 described above in that the lower insulating member 40 is provided with a fixing portion 43, which is provided on the side of the lower insulating member 40 facing the end cap 10. Specifically, the fixing portion 43 is located on the bottom wall surface of the sub-mounting groove 4042 (not marked in the figure) and protrudes from the bottom wall surface of the sub-mounting groove 4042 toward the third surface 401. The fixing portion 43 is located on the side of the third surface 401 facing the fourth surface 402. That is, the fixing portion 43 does not protrude relative to the third surface 401 to prevent the fixing portion 43 from affecting the assembly stability between the lower insulating member 40 and the end cap 10. In this embodiment, there are multiple fixing portions 43, and the multiple fixing portions 43 are arranged at intervals. There are four fixing portions 43, and every two fixing portions 43 are provided on the bottom wall surface of a sub-mounting groove 4042, and are arranged at intervals along the length direction of the lower insulating member 40. Exemplarily, the fixing portion 43 can be a hot melt column.

[0154] See also Figure 15 , Figure 15 yes Figure 2 The end cap assembly 120 is a schematic structural diagram of the bracket 50 in the second embodiment.

[0155] The bracket 50 is provided with a fixing hole 501. The fixing hole 501 passes through the bracket 50 along the thickness direction of the bracket 50. In this embodiment, there are multiple fixing holes 501. A part of the fixing holes 501 is provided on the second mounting portion 52, and passes through the second mounting portion 52 along the thickness direction of the second mounting portion 52 (that is, passes through the second overlapping surface 521 and the second mating surface 522), and are spaced apart from each other. Another part of the fixing holes 501 is provided on the first mounting portion 53, and passes through the first mounting portion 53 along the thickness direction of the first mounting portion 53 (that is, passes through the first overlapping surface 531 and the first mating surface 532), and are spaced apart from each other. Among them, there are four fixing holes 501. Two fixing holes 501 are provided on the second mounting portion 52, and are spaced apart along the width direction of the bracket 50. Two fixing holes 501 are provided on the second mounting portion 52, and are spaced apart along the width direction of the bracket 50.

[0156] See also Figure 16 and Figure 17 , Figure 16 yes Figure 2 The schematic diagram of the assembly structure of the lower insulating member 40 and the bracket 50 of the end cap assembly in the second embodiment is shown. Figure 17 yes Figure 16 The structure shown is a schematic diagram of the structure after being cut along III-III.

[0157] The bracket 50 is mounted on the lower insulator 40. Specifically, the bracket 50 is mounted in the mounting slot 404. The first mounting portion 53 and the second mounting portion 52 are respectively mounted in the two sub-mounting slots 4042. The multiple fixing portions 43 of the lower insulator 40 are inserted through the multiple fixing holes 501 of the bracket 50 and are fixedly connected to the bracket 50 to ensure the assembly stability between the bracket 50 and the lower insulator 40. For example, the fixing portions 43 can be fixedly connected to the bracket 50 by melting and collapsing them through heat.

[0158] See also Figures 18 to 20 , Figure 18 yes Figure 2 The schematic structural diagram of the lower insulating member 40 of the end cap assembly 120 in the third embodiment is shown. Figure 19 yes Figure 2 The schematic diagram of the assembly structure of the lower insulating member 40 and the bracket 50 of the end cap assembly 120 in the third embodiment is shown. Figure 20 yes Figure 19 The structure shown is a schematic diagram of the structure after being cut along IV-IV.

[0159] The end cap assembly 120 shown in this embodiment differs from the end cap assembly 120 shown in the second embodiment described above in that the fixing portion 43 is a snap-fit ​​portion, and the fixing hole 501 is a snap-fit ​​hole. The fixing portion 43 snap-fits with the fixing hole 501 to ensure assembly stability between the bracket 50 and the lower insulator 40. In other words, the fixing portion 43 is fixedly connected to the lower insulator 40 through a snap-fit ​​method.

[0160] See also Figures 21 to 23 , Figure 21 yes Figure 2 The end cap assembly 120 is a schematic structural diagram of the fourth embodiment after being cut along the II. Figure 22 yes Figure 21 The schematic structural diagram of the bracket 50 in the end cover assembly 120 is shown. Figure 23 yes Figure 22 The structure of the bracket 50 shown is a schematic diagram at another angle.

[0161] The end cap assembly 120 shown in this embodiment differs from the end cap assemblies 120 shown in the first to third embodiments described above in that, in the bracket 50, the second through hole 515 and the first through hole 516 are staggered along the width direction of the bracket 50. Specifically, along the width direction of the bracket 50, the fourth hole wall 5151 is located on the side of the first hole wall 5162 away from the second hole wall 5161 and is spaced apart from the first hole wall 5162. The first hole wall 5162 is located on the side of the fourth hole wall 5151 away from the third hole wall 5152 and is spaced apart from the fourth hole wall 5151.

[0162] Please also refer to Figures 24 to 26 , Figure 24 yes Figure 21 The schematic diagram of the partial assembly structure of the end cap 10, the lower insulating member 40 and the bracket 50 in the end cap assembly 120 is shown. Figure 25 yes Figure 24 The structure shown is a schematic diagram of the structure after being cut along VV. Figure 26 Schematic diagram of the gas flow path when thermal runaway occurs in the energy storage device 100, wherein the energy storage device 100 adopts the end cap assembly 120 shown in the fourth embodiment. It should be noted that, Figure 26 The dashed line with an arrow is the flow path of the gas.

[0163] In this embodiment, the second free end surface 562 is located on the side of the second fixed end surface 561 away from the center line O of the explosion-proof hole 103, and the first free end surface 572 is located on the side of the first fixed end surface 571 away from the center line of the explosion-proof hole 103. When thermal runaway occurs in the energy storage device 100, the high-temperature gas on the left side hits the third guide surface 564 of the second guide portion 56 from the gap between the first side surface 511 and the first groove side wall surface 404a, and will be ejected from the explosion-proof hole 103 along the direction of the third guide surface 564. The high-temperature gas on the right side hits the first guide surface 574 of the first guide portion 57 from the gap between the second side surface 512 and the second groove side wall surface 404b, and will be ejected from the explosion-proof hole 103 along the direction of the first guide surface 574. At this time, the high-temperature gas will be ejected from the explosion-proof hole 103 in a parabolic manner, not only Carbonized debris, molten aluminum beads, electrolyte and other substances carried by the high-temperature gas can be ejected farther, thereby preventing the carbonized debris, molten aluminum beads, electrolyte and other substances from accumulating around the explosion-proof hole 103. Moreover, since the densities of carbonized debris, molten aluminum beads, electrolyte and other substances vary, the ejection distances of substances with different densities will also vary. Therefore, substances with different densities will be stratified and 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.

[0164] See also Figures 27 to 29 , Figure 27 yes Figure 2 The end cap assembly 120 is a schematic structural diagram of the fifth embodiment after being cut along II. Figure 28 yes Figure 27 The schematic structural diagram of the bracket 50 in the end cover assembly 120 is shown. Figure 29 yes Figure 28 The structure of the bracket 50 shown is a schematic diagram at another angle.

[0165] The end cap assembly 120 shown in this embodiment differs from the end cap assemblies 120 shown in the first to third embodiments described above in that the shielding portion 51 does not have the second through hole 515, and the bracket 50 does not include the second air guide 56. That is, the shielding portion 51 only has the first through hole 516. The bracket 50 includes the first air guide 57.

[0166] Please also refer to Figure 30 and Figure 31 , Figure 30 yes Figure 27 The schematic diagram of the partial assembly structure of the end cap 10, the lower insulating member 40 and the bracket 50 in the end cap assembly 120 is shown. Figure 31 yes Figure 30 The structure shown is a schematic diagram of the structure after being cut along VI-VI. Figure 31 The dashed line with an arrow in the middle is the flow path of the gas when the energy storage device 100 is in thermal runaway.

[0167] When the energy storage device 100 experiences thermal runaway, the high-temperature gas on the left side impacts the second guide surface 573 of the first guide portion 57 from the gap between the first side surface 511 and the first groove side wall surface 404a, and is affected by the airflow of the first through hole 516. The airflow direction rotates more than 90 degrees and is ejected from the explosion-proof hole 103 along the direction of the second guide surface 573. The high-temperature gas on the right side impacts the first guide surface 574 of the first guide portion 57 from the gap between the second side surface 512 and the second groove side wall surface 404b, and is ejected from the explosion-proof hole 103 along the direction of the first guide surface 574. At this time, the high-temperature gas will be in a parabolic direction. The carbonized debris, molten aluminum beads, electrolyte and other substances carried by the high-temperature gas can be ejected farther, thereby preventing the carbonized debris, molten aluminum beads, electrolyte and other substances from accumulating around the explosion-proof hole 103. In addition, since the densities of the carbonized debris, molten aluminum beads, electrolyte and other substances are different, the ejection distances of substances with different densities will also be different. Therefore, substances with different densities will be stratified and 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 the safety risks of the energy storage device 100, and improve the reliability of the energy storage device 100.

[0168] 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.

[0169] The above description is only specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered in the protection scope of the present application; in the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application should be subject to the protection scope 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 has a first surface and a second surface. Along the thickness direction of the end cover, the first surface and the second surface are arranged opposite to each other. The end cover is provided with an explosion-proof hole, and the explosion-proof hole passes through the first surface and the second surface. The explosion-proof valve is installed on the end cover and covers the explosion-proof hole; The lower insulating member is located on a side of the second surface away from the first surface. The lower insulating member has a third surface and a fourth surface. The third surface is arranged opposite to the second surface, and the fourth surface is arranged opposite to the third surface. The lower insulating member is provided with a through groove, which passes through the third surface and the fourth 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 pass through the through slot, and the melting point of the bracket is greater than the melting point of the lower insulating member; The bracket includes a shielding portion and a first guide portion, the shielding portion is located on a side of the fourth surface facing away from the third surface, and is spaced apart from the fourth surface and opposite to the through groove, wherein the orthographic projection of the explosion-proof valve on the bracket covers at least a portion of the shielding portion, the shielding portion is provided with a first through hole, the first through hole penetrates the shielding portion along the thickness direction of the shielding portion, the first through hole has a first hole wall surface and a second hole wall surface, along the length direction of the end cover assembly, the first hole wall surface and the second hole wall surface are spaced apart and opposite to each other, the first guide portion is fixedly connected to the first hole wall surface, and is opposite to the first through hole, the first guide portion has a first guide surface facing the lower insulating member, the angle between the first guide surface and the shielding portion is not equal to 90 degrees, and the plane where the first guide surface is located intersects with the opening of the explosion-proof hole on the first surface.

2. The end cap assembly according to claim 1, wherein: An included angle between the first guide surface and the shielding portion is greater than or equal to 25 degrees and less than or equal to 85 degrees.

3. The end cap assembly according to claim 2, wherein: An included angle between the first guide surface and the shielding portion is greater than or equal to 35 degrees and less than or equal to 55 degrees.

4. The end cap assembly according to any one of claims 1 to 3, characterized in that: The first guide portion further has a second guide surface, which is arranged opposite to the first guide surface and the angle between the second guide surface and the shielding portion is not equal to 90 degrees. The plane where the second guide surface is located intersects with the opening of the explosion-proof hole on the first surface.

5. The end cap assembly according to claim 4, wherein: The explosion-proof hole has a center line, and along the length direction of the end cover assembly, the distance between the center line and the hole wall of the explosion-proof hole is W; The first guide portion has a first fixed end face and a first free end face, the first fixed end face is fixedly connected to the first hole wall, the first free end face is arranged opposite to the first fixed end face, and is located on the side of the first fixed end face facing the center line, the first guide surface and the second guide surface are symmetrical about the center plane of the first guide portion, the intersection line of the plane where the center plane of the first guide portion is located and the opening of the explosion-proof hole on the first surface is the first intersection line, along the length direction of the end cover assembly, the distance between the first intersection line and the center line is S1, and the ratio of S1 to W is greater than or equal to 0 and less than or equal to 0.

8.

6. The end cap assembly according to claim 5, wherein: The ratio of S1 to W is greater than or equal to 0 and less than or equal to 0.

3.

7. The end cap assembly according to claim 1, wherein: The bracket includes a first mounting portion and a first connecting portion. Along the thickness direction of the end cap assembly, the first mounting portion is located on one side of the shielding portion and is spaced apart from the shielding portion. The first mounting portion has a first overlapping surface, which overlaps the lower insulating member. The first connecting portion is connected between the shielding portion and the first mounting portion. The first guide portion has a first fixed end face and a first free end face, the first fixed end face is fixedly connected to the first hole wall surface, the first free end face is located on the first lap surface facing the first fixed end face, and the minimum distance between the first free end face and the first lap surface in the thickness direction of the end cover assembly is greater than or equal to 1 mm and less than or equal to 2 mm.

8. The end cap assembly according to any one of claims 1 to 3, characterized in that: The shielding portion is further provided with a second through hole, the second through hole penetrating the shielding portion along the thickness direction of the shielding portion, the first through hole and the second through hole being spaced apart in the width direction of the end cover assembly, the second through hole having a third hole wall surface and a fourth hole wall surface, the third hole wall surface and the fourth hole wall surface being spaced apart and opposite to each other in the length direction of the end cover assembly; The bracket also includes a second guide portion, which is fixedly connected to the wall of the fourth hole and is arranged opposite to the second through hole. The second guide portion has a third guide surface facing the lower insulating member. The angle between the third guide surface and the shielding portion is not equal to 90 degrees, and the plane where the third guide surface is located intersects with the opening of the explosion-proof hole on the first surface.

9. The end cap assembly according to claim 8, wherein: An included angle between the third guide surface and the shielding portion is greater than or equal to 25 degrees and less than or equal to 85 degrees.

10. The end cap assembly according to claim 8, wherein: The explosion-proof hole has a center line, the first guide portion is inclined in a first direction relative to the shielding plate, the second guide portion is inclined in a second direction relative to the shielding plate, and the first direction and the second direction are symmetrically arranged about the center line.

11. The end cap assembly according to claim 1, wherein: The bracket further includes a first mounting portion, a second mounting portion, a first connecting portion, and a second connecting 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 spaced apart from the shielding portion. 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 mounting portion and the second mounting portion are fixedly mounted on the second surface.

12. The end cap assembly according to claim 1, wherein: The bracket further includes a first mounting portion, a second mounting portion, a first connecting portion, and a second connecting 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 spaced apart from the shielding portion. 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 bracket is provided with a plurality of fixing holes, a portion of which is provided on the first mounting portion and passes through the first mounting portion along a thickness direction of the first mounting portion and is spaced apart from each other, and another portion of which is provided on the second mounting portion and passes through the second mounting portion along a thickness direction of the second mounting portion and is spaced apart from each other; The lower insulating member is provided with a plurality of fixing parts, which are all provided on a side of the lower insulating member facing the end cover, and are respectively passed through the corresponding fixing holes and fixedly connected to the bracket.

13. 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 12, 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.

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

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