End cap assembly, energy storage device, and electrical device

Abstract

The application provides an end cover assembly, an energy storage device and an electric equipment. In the end cover, an explosion-proof hole penetrates a first surface and a second surface, a groove is arranged around the explosion-proof hole, a convex part is arranged on a groove bottom wall surface and around the explosion-proof hole, a convex surface is located on a side of the first surface facing the groove bottom wall surface and is arranged in a thickness direction of the end cover and spaced from the first surface, and a first peripheral surface is arranged around the convex part. An explosion-proof valve is installed on the end cover and covers the explosion-proof hole. A protection sheet is installed on the convex surface and covers the explosion-proof hole, a third surface is located on a side of the first surface facing the second surface, and a second peripheral surface of the protection sheet is spaced from and oppositely arranged with a groove side wall surface.

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 to activate the active materials and continue to be used after being discharged. The recyclable nature of secondary batteries has made them a major power source for electrical equipment. As the demand for secondary batteries increases, people's performance requirements in all aspects are also getting higher and higher, especially the requirements for the reliability of secondary batteries. Secondary batteries are equipped with explosion-proof valves, which can be used to release air and pressure in advance when thermal runaway occurs to prevent the secondary battery from exploding. Due to the weak strength of the explosion-proof valve, a protective plate is required to protect the explosion-proof valve. However, the height of the protective plate often exceeds the end cap. The protective plate is easily bumped, damaged, or detached during manufacturing and transportation, resulting in the protective plate being unable to effectively protect the explosion-proof valve, affecting the valve opening stability of the explosion-proof valve. Summary of the Invention

[0003] The present application provides an end cover assembly, an energy storage device and an electrical device, which are used to prevent the protective sheet from being damaged or falling off due to collisions during the manufacturing and transportation process, ensure that the protective sheet effectively protects the explosion-proof valve, and ensure the opening stability of the explosion-proof valve.

[0004] In a first aspect, the present application provides an end cap assembly for use in an energy storage device, comprising an end cap, an explosion-proof valve, and a protective sheet;

[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 and a groove. The explosion-proof hole passes through the first surface and the second surface. The opening of the groove is located on the first surface. The groove is arranged around the explosion-proof hole. The groove has a groove bottom wall surface and a groove side wall surface. The groove bottom wall surface is arranged opposite to the opening of the groove. The groove side wall surface is arranged around the groove bottom wall surface and is connected to the groove bottom wall surface.

[0006] The end cover is further provided with a raised portion, which is provided on the bottom wall of the groove, surrounds the explosion-proof hole, and is spaced apart from the side wall of the groove. The raised portion has a raised surface and a first peripheral surface. The raised surface is the surface of the raised portion facing away from the bottom wall of the groove, and is located on the side of the first surface facing the bottom wall of the groove, and is spaced apart from the first surface in the thickness direction of the end cover. The first peripheral surface is the surface of the raised portion facing the side wall of the groove, surrounds the raised portion, and is connected between the bottom wall of the groove and the raised surface.

[0007] The explosion-proof valve is installed on the end cover and covers the opening of the explosion-proof hole on the second surface;

[0008] The protective sheet is installed on the raised surface, covers the explosion-proof hole, and is spaced apart from the side wall of the groove. The protective sheet has a third surface and a second circumferential surface. The third surface is the surface of the protective sheet facing away from the raised portion. The third surface is flush with the first surface, or the third surface is located on the side of the first surface facing the second surface. The second circumferential surface is arranged around the third surface and is connected to the third surface, and is spaced apart from and opposite to the side wall of the groove.

[0009] In the end cap assembly described in this application, the protective sheet does not protrude relative to the end cap. This not only prevents the protective sheet from being damaged or falling off due to collisions during the manufacture or transportation of the energy storage device, ensuring that the protective sheet effectively protects the explosion-proof valve and ensures the stability of the explosion-proof valve's opening, but also prevents interference with the top patch when attaching it, ensuring the reliability of the protective sheet. Furthermore, the protective sheet covers the groove, which can reduce the exposed area of ​​the end cap, prevent the end cap from overlapping and conducting with external components, and help improve the reliability of the energy storage device.

[0010] The end cap assembly further includes a top patch mounted on the first surface. The top patch is provided with a first avoidance hole, which extends through the top patch along its thickness and avoids the protective sheet. The orthographic projection of the first avoidance hole wall surface on the plane of the groove bottom wall surface is located between the first circumferential surface and the groove side wall surface. The top patch covers the groove, reducing the exposed area of ​​the end cap and preventing overlap and electrical conduction between the end cap and external components, thereby improving the reliability of the energy storage device.

[0011] Among them, the orthographic projection of the hole wall surface of the first avoidance hole on the plane where the bottom wall surface of the groove is located is located between the orthographic projection of the second circumferential surface on the plane where the bottom wall surface of the groove is located and the side wall surface of the groove, thereby avoiding interference between the top patch and the protective sheet and ensuring the assembly stability of the end cover assembly.

[0012] The end cover is further provided with a liquid injection hole, which is spaced apart from the groove and passes through the first surface and the second surface;

[0013] The protective sheet comprises a protective layer and an adhesive layer, the protective layer is located on the side of the convex surface away from the groove bottom wall surface, the adhesive layer is located between and bonded to the protective layer and the convex surface, the adhesive layer has a third peripheral surface and a fourth peripheral surface, the third peripheral surface is the surface of the adhesive layer facing the groove side wall surface, the fourth peripheral surface is located opposite to the third peripheral surface, the adhesive layer is provided with a through hole, the through hole is located on the side of the adhesive layer away from the liquid injection hole and penetrates through the third peripheral surface and the fourth peripheral surface.

[0014] The through hole not only provides positioning for the attached protective sheet, but also has the same effect as the exhaust groove, can balance the air pressure of the explosion-proof hole and the groove, avoid the gas between the explosion-proof valve and the protective sheet being closed, and the explosion-proof valve and the protective sheet being bulged or recessed due to the internal and external pressure difference caused by the altitude. Moreover, since the through hole is located away from the liquid injection hole, the electrolyte can be prevented from entering the explosion-proof hole from the through hole when the liquid injection hole sprays liquid, thereby preventing the explosion-proof valve from being polluted, and ensuring the use reliability of the explosion-proof valve.

[0015] The convex part further has a fifth peripheral surface located opposite to the first peripheral surface and connected to the convex surface.

[0016] The end cover further has an exhaust groove located on the side of the convex part away from the liquid injection hole, the exhaust groove penetrates through the convex surface, the first peripheral surface and the fifth peripheral surface, and is correspondingly arranged with the through hole.

[0017] The exhaust groove can balance the air pressure of the explosion-proof hole and the groove, avoid the gas between the explosion-proof valve and the protective sheet being closed, and the explosion-proof valve and the protective sheet being bulged or recessed due to the internal and external pressure difference caused by the altitude. Moreover, since the exhaust groove is located away from the liquid injection hole, the electrolyte can be prevented from entering the explosion-proof hole from the exhaust groove when the liquid injection hole sprays liquid, thereby preventing the explosion-proof valve from being polluted, and ensuring the use reliability of the explosion-proof valve.

[0018] The end cover further has a first negative electrode post hole and a first positive electrode post hole, the first negative electrode post hole and the first positive electrode post hole both penetrate through the first surface and the second surface, and are spaced apart from the groove and the liquid injection hole, wherein the distance between the liquid injection hole and the first negative electrode post hole is greater than the distance between the liquid injection hole and the first positive electrode post hole.

[0019] The end cover assembly further comprises a negative electrode upper insulating piece, a positive electrode upper insulating piece, a positive electrode post, a negative electrode post, a negative electrode pressing block and a second riveting pressing block.

[0020] The negative electrode upper insulating member and the positive electrode upper insulating member are both provided on a side of the first surface away from the second surface and are spaced apart from each other. The negative electrode upper insulating member is provided with a second negative electrode post hole, which passes through the negative electrode upper insulating member along the thickness direction of the negative electrode upper insulating member and is communicated with the first negative electrode post hole. The positive electrode upper insulating member is provided with a second positive electrode post hole, which passes through the positive electrode upper insulating member along the thickness direction of the positive electrode upper insulating member and is communicated with the first positive electrode post hole. The resistivity of the positive electrode upper insulating member is within 1×10 3 ohm / sq to 1×10 10 ohm / sq, so that the insulating member on the positive electrode has weak conductivity;

[0021] The negative electrode post is inserted into the first negative electrode post hole and the second negative electrode post hole, and the positive electrode post is inserted into the first positive electrode post hole and the second positive electrode post hole;

[0022] The negative electrode pressing block is installed on the negative electrode upper insulating member, and is sleeved on the negative electrode column and fixedly connected to the negative electrode column. The positive electrode pressing block is installed on the positive electrode upper insulating member, and is sleeved on the positive electrode column and fixedly connected to the positive electrode column.

[0023] Since the insulating part on the positive electrode has weak conductivity and the positive electrode column and the end cover are weakly conductively connected, no short circuit will occur when the injection hole overlaps with the positive electrode column when spraying liquid. The injection hole is designed to be close to the first positive electrode column hole, which can avoid the possibility of short circuit caused by the injection hole overlapping with the negative electrode column when spraying liquid.

[0024] The negative electrode pressing block has a first assembly surface and a second assembly surface, the first assembly surface is the surface of the negative electrode pressing block facing the end cover, and the second assembly surface is arranged opposite to the first assembly surface. The negative electrode pressing block is provided with a rivet hole, and the rivet hole passes through the first assembly surface and the second assembly surface;

[0025] The negative electrode column includes a flange portion, a rivet portion and a connecting portion. The flange portion is located on the side of the second surface facing away from the first surface. The rivet portion is located on one side of the flange portion and is spaced apart from the flange portion and is connected and matched with the rivet hole. The connecting portion is fixedly connected between the flange portion and the rivet portion and is passed through the first positive electrode column hole and the second positive electrode column hole. The connecting portion has a mating surface facing away from the flange portion, and the mating surface is connected to the first assembly surface.

[0026] The negative electrode column and the negative electrode pressing block are fixed together through riveting, which not only simplifies the assembly of the negative electrode column and the negative electrode pressing block, but also improves the assembly stability of the negative electrode column and the negative electrode pressing block. Furthermore, because the mating surface of the connecting portion abuts the first assembly surface of the negative electrode pressing block, the effective flow area of ​​the end cap assembly is increased, reducing the internal resistance of the energy storage device, improving the flow efficiency of the end cap assembly, and thus improving the energy efficiency of the energy storage device.

[0027] The rivet hole includes a first hole portion, a second hole portion, and a third hole portion, wherein the second hole portion is located on a side of the first hole portion away from the end cover and is spaced apart from the first hole portion, and the third hole portion communicates with the first hole portion and the second hole portion, wherein the diameter of the third hole portion is larger than the diameter of the first hole portion and smaller than the diameter of the second hole portion;

[0028] The riveted portion includes a first part, a second part and a third part. The first part is fixedly connected to the connecting portion and riveted to the first hole portion. The circumferential surface of the first part is connected to the hole wall surface of the first hole portion. The second part is located on the side of the first part away from the connecting portion and is connected to the second hole portion. The circumferential surface of the second part is connected to the hole wall surface of the second hole portion. The third part is fixedly connected between the first and third parts and is connected to the third hole portion. The circumferential surface of the third part is connected to the hole wall surface of the third hole portion. The diameter of the third part is larger than the diameter of the first part and smaller than the diameter of the second part.

[0029] The diameter of the negative electrode flange is larger than the diameter of the rivet and connection. This ensures that the rivet expands during riveting and assembly, thereby ensuring the strength of the connection between the negative electrode and the negative electrode block. Furthermore, the larger diameter of the flange improves the negative electrode's pressure resistance, preventing significant expansion and deformation of the flange during the riveting process. This ensures the dimensional stability of the connection and prevents the thickness of the connection from being reduced due to riveting. This ensures that the creepage distance and electrical clearance of the negative electrode are not compressed, thus ensuring the safe use of the energy storage device.

[0030] Among them, the circumferential surface of the third part includes a first abutting part, a first chamfered part and a second chamfered part, the first abutting part is an inclined surface, the first chamfered part is connected between the first abutting part and the circumferential surface of the first part, and the second chamfered part is connected between the first abutting part and the circumferential surface of the second part.

[0031] The inclined surface formed between the negative electrode column and the negative electrode pressing block can improve the flow capacity of the end cover assembly and improve the energy efficiency of the energy storage device.

[0032] Wherein, the diameter of the flange portion is greater than or equal to 1.5 times the diameter of the first portion.

[0033] Since the diameter of the flange portion is greater than or equal to 1.5 times the diameter of the first portion, the diameter of the flange portion can be ensured to be large enough, which can increase the effective flow area of ​​the end cover assembly, reduce the internal resistance of the energy storage device, improve the flow effect of the end cover assembly, and thus improve the energy efficiency of the energy storage device.

[0034] Wherein, the diameter of the first hole portion is greater than or equal to 1.5 times the diameter of the third hole portion.

[0035] The aperture of the second hole portion is greater than or equal to 1.5 times the aperture of the first hole portion, which can ensure that during the riveting process of the negative electrode column and the negative electrode pressure block, the riveted portion can effectively expand and cooperate with the riveted hole to be fixed. This not only ensures the expansion amount and riveting strength of the riveted portion, but also facilitates the formation of an inclined surface between the first abutting portion and the second abutting portion, thereby improving the flow capacity of the end cover assembly and improving the energy efficiency of the energy storage device.

[0036] 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.

[0037] In which, the energy storage device also includes an insulating film, which includes a first insulating film portion and a second insulating film portion. The first insulating film portion covers the outer surface of the shell, the second insulating film portion is connected to the first insulating film portion, and is arranged on the first surface and covers part of the groove, and the top patch covers the second insulating film portion.

[0038] Because the second insulating film partially covers the groove, it improves the attachment of the top patch to the end cap and reduces the overhanging area of ​​the top patch. Furthermore, the protective sheet, second insulating film, and top patch all cover the groove, reducing the exposed area of ​​the end cap and preventing contact and electrical conduction between the end cap and external components, thereby improving the reliability of the energy storage device.

[0039] The second insulating film portion includes two sub-insulating film portions. Along the width direction of the end cover, the two sub-insulating film portions are respectively arranged on opposite sides of the protective sheet, spaced apart from the protective sheet, and cover opposite ends of the groove.

[0040] 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

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used by the embodiments of the present application will be described below.

[0042] Figure 1 is a structural schematic diagram of an energy storage system according to an embodiment of the present application;

[0043] Figure 2 is a structural schematic diagram of an energy storage device provided by the present application;

[0044] Figure 3 is Figure 2 is a structural schematic diagram of an end cover assembly in the energy storage device shown in the figure;

[0045] Figure 4 is Figure 3 is a sectional structural schematic diagram of the end cover assembly shown in the figure after being cut along I-I;

[0046] Figure 5 is Figure 2 is an exploded structural schematic diagram of the end cover assembly shown in the figure;

[0047] Figure 6 is Figure 5 is a structural schematic diagram of an end cover in the end cover assembly shown in the figure;

[0048] Figure 7 is Figure 6 is a sectional structural schematic diagram of the end cover shown in the figure after being cut along II-II;

[0049] Figure 8 is Figure 5 is an assembled structural schematic diagram of the end cover, the explosion-proof valve and the protective sheet in the end cover assembly shown in the figure;

[0050] Figure 9 is Figure 8 is a sectional structural schematic diagram of the assembled structure shown in the figure after being cut along III-III;

[0051] Figure 10 is Figure 5 is a structural schematic diagram of the protective sheet in the end cover assembly shown in the figure from another angle;

[0052] Figure 11 is Figure 5 is an assembled structural schematic diagram of the end cover, the explosion-proof valve and the protective sheet and the second insulating film part of the insulating film in the end cover assembly shown in the figure;

[0053] Figure 12 is Figure 11 is a sectional structural schematic diagram of the assembled structure shown in the figure after being cut along IV-IV;

[0054] Figure 13 is Figure 5A schematic diagram of the assembly structure of the end cap, explosion-proof valve, protection sheet, top patch and the second insulating film portion of the insulating film in the end cap assembly shown;

[0055] Figure 14 yes Figure 13 The schematic cross-sectional view of the assembly structure shown is taken along VV;

[0056] Figure 15 yes Figure 4 An enlarged structural diagram of area A in the end cap assembly shown;

[0057] Figure 16 yes Figure 4 An enlarged structural diagram of area B in the end cap assembly shown;

[0058] Figure 17 yes Figure 16 A schematic diagram of the structure of the negative electrode column in the end cap assembly shown;

[0059] Figure 18 yes Figure 16 Schematic diagram of the structure of the negative electrode block in the end cover assembly shown.

[0060] The names corresponding to the reference numerals in the figures are:

[0061] 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, upper insulator 50, pole 60, riveted pressure ring 70, sealing ring 80, top patch 90, negative pole upper insulator 51, positive pole upper insulator 52, negative pole 61, positive pole 62, negative pole pressing block 71, Positive electrode pressing block 72, first sealing ring 81, second sealing ring 82, first surface 101, second surface 102, explosion-proof hole 103, groove 104, injection hole 105, first negative electrode column hole 106, first positive electrode column hole 107, groove bottom wall 1041, groove side wall 1042, raised portion 11, raised surface 111, first peripheral surface 112, fifth peripheral surface 113, exhaust groove 108, third surface 301, second peripheral surface 302, protective layer 31, Adhesive layer 32, fourth surface 311, sixth circumferential surface 312, third circumferential surface 321, fourth circumferential surface 322, through hole 303, second insulating film portion 132, sub-insulating film portion 133, free end surface 134, first avoidance hole 901, second avoidance hole 902, third avoidance hole 903, explosion-proof fence 41, liquid inlet hole 401, third negative electrode column hole 402, third positive electrode column hole 403, second negative electrode column hole 501, second positive electrode column hole 502, flange portion 63, rivet portion 64, connecting portion 65, mating surface 651, first portion 66, second portion 67, third portion 68, first abutting portion 681, first chamfered portion 682, second chamfered portion 683, first assembly surface 701, second assembly surface 702, rivet hole 703, first hole portion 704, second hole portion 705, third hole portion 706, second abutting portion 7061, third chamfered portion 7062 and fourth chamfered portion 7063. DETAILED DESCRIPTION

[0062] 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.

[0063] 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.

[0064] 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.

[0065] Taking electrochemical energy storage as an example, this solution provides an energy storage device for use in energy storage systems. The energy storage device 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 battery. When the use of external electricity reaches its peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0066] 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 include:

[0067] (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 capacity 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.

[0068] (2) Energy storage containers used on the grid side are mainly used for peak shaving, frequency regulation, and relief of grid congestion. They can realize peak shaving and valley filling of electricity load, that is, charging the energy storage battery when the electricity load is low and releasing the stored electricity during the peak period, thereby achieving a balance between electricity production and consumption;

[0069] (3) Small energy storage cabinet applied to power consumption side, the main functions are power self-generation and self-use, peak-valley price difference arbitrage, capacity cost management and improvement of power supply reliability. According to different application scenarios, the energy storage of power consumption side can be divided into industrial and commercial energy storage cabinet, household energy storage device, energy storage charging pile, etc., which is generally used with distributed photovoltaic. Industrial and commercial users can use energy storage for valley-peak price difference arbitrage and capacity cost management. In the electricity market implementing peak-valley electricity price, through charging the energy storage system at low electricity price and discharging the energy storage system at high electricity price, the peak-valley price difference arbitrage is realized, and the electricity cost is reduced. In addition, for industrial enterprises applying two-part electricity price, the energy storage system can be used to store energy at low electricity consumption and discharge at peak load, so as to reduce the maximum demand amount of sharp peak power and report, and achieve the purpose of reducing capacity electricity cost. Household photovoltaic with storage can improve the level of power self-generation and self-use. Due to high electricity price and poor power supply stability, the demand for household photovoltaic installation is increased. Considering that photovoltaic generates electricity in the daytime and users generally have high load at night, through the configuration of energy storage, photovoltaic power can be better utilized, the level of self-generation and self-use is improved, and the electricity cost is reduced. In addition, communication base stations, data centers and other fields need to configure energy storage for backup power supply.

[0070] In some embodiments, please refer to Figure 1 , Figure 1 is a structural schematic diagram of an energy storage system 400 of an embodiment of the present application, and the present application Figure 1 Embodiments take the shared energy storage scenario of power generation and distribution side as an example for description, and the energy storage device 100 of the present application is not limited to the energy storage scenario of power generation and distribution side.

[0071] The application provides a kind of energy storage system 400, the energy storage system 400 includes: high voltage cable 410, first electric energy conversion device 420, second electric energy conversion device 430 and the energy storage device 100 provided by the application, in some embodiments of power generation side scene, second electric energy conversion device 430 can be wind power electric energy conversion device, due to the fluctuation, randomness and intermittence of wind power electric energy conversion generated electric energy, unstable electric energy output by wind power electric energy conversion device can be stored to energy storage device 100 by grid connection first, energy storage device 100 is connected with high voltage cable 410 and exports smooth electric energy to supply distribution network for power consumption side, realize peak shaving and frequency modulation, grid stable operation;Or, wind power electric energy conversion device is always connected with high voltage cable 410, and the electric energy output by wind power electric energy conversion device is supplied to distribution network for power consumption side by high voltage cable in ordinary power generation, and when current power consumption load is low, wind power electric energy conversion device generates excess, first store the electric quantity of overproduction to energy storage device 100, reduce the rate of abandoned wind and light, improve new energy power generation consumption problem;And when power consumption load is high, grid issues an order, and the electric quantity stored in energy storage device 100 is transmitted to power consumption side by grid connection mode with high voltage cable 410, provides peak shaving, frequency modulation, backup and other services for grid operation, fully plays the role of grid peak shaving, promotes grid peak clipping, and relieves grid power supply pressure.

[0072] In some embodiments of distribution network side, first electric energy conversion device 420 can be photovoltaic electric energy conversion device, energy storage device 100 is connected with high voltage cable 410 and is installed between downstream of high voltage cable 410 and user load, and the electric energy output by photovoltaic electric energy conversion device is stored in energy storage device 100, which can be used as backup power source in time when grid / distribution network fails;Or, when high voltage cable 410 transmission line appears line congestion, it can relieve line congestion and provide power supply support to delay economic pressure generated by grid / distribution expansion.

[0073] Optionally, the first electric energy conversion device can include but is not limited to wind power electric energy conversion device, and the second electric energy conversion device can include but is not limited to photovoltaic electric energy conversion device, and 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, heat energy, tidal energy, biomass energy and mechanical energy into electric energy.

[0074] Optionally, energy storage device 100 can include but is not limited to energy storage application scenarios such as energy storage power station, hydraulic / thermal / wind power generation system, solar power generation system, mobile power system, smart home system or temporary power supply system, and is also applied to data center, military equipment, aerospace, charging pile, electric vehicle and other fields.

[0075] Optionally, the energy storage device 100 can include, but is not limited to, a single battery cell, a battery module composed of single battery cells, a battery pack, a battery cluster, a mobile power supply, a battery integrated system such as a battery cabinet / battery container, etc. The actual application form of the energy storage device 100 provided in the embodiments of the present application can be, but is not limited to, the listed products, and can also be other application forms. The embodiments of the present application do not strictly limit the application form of the energy storage device 100. The embodiments of the present application only take the multi-core battery as an example for description.

[0076] Please refer to Figure 2 , Figure 2 is a structural schematic diagram of the energy storage device 100 provided in the present application.

[0077] The present application provides an energy storage device 100, which can include, but is not limited to, a single battery cell, a battery module, a battery pack, a battery system, etc. Optionally, when the energy storage device 100 is a single battery cell, the energy storage device 100 can be, but is not limited to, at least one of a cylindrical battery, a square battery, a prismatic battery or other shaped batteries. The single battery cell can be a secondary battery, which means that the battery cell can be activated by charging after discharging to continue to be used. The single battery cell can 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. The present application does not make specific limitations. It should be noted that the actual application form of the energy storage device 100 provided in the embodiments of the present application can be, but is not limited to, the listed products, and can also be other application forms. The embodiments of the present application do not strictly limit the application form of the energy storage device 100. The embodiments of the present application take the square battery as an example for description.

[0078] The energy storage device 100 includes a housing 110, a cell assembly (not shown), an end cap assembly 120, and an insulating film (not shown). The housing 110 is provided with a receiving cavity (not shown) and an opening (not shown). The receiving cavity is located inside the housing 110 and contains electrolyte. The opening is located at the top of the receiving cavity and communicates with the receiving cavity. The housing 110 can be made of aluminum, for example, an aluminum shell. The cell assembly is housed in the receiving cavity. The cell assembly can be immersed in the electrolyte. The end cap assembly 120 is mounted on the housing 110, closes the opening, and is electrically connected to the cell assembly. The length of the end cap assembly 120 is parallel to the length of the energy storage device 100, the width of the end cap assembly 120 is parallel to the width of the energy storage device 100, and the thickness of the end cap assembly 120 is parallel to the height of the energy storage device 100. The insulating film includes a first insulating film portion and a second insulating film portion. The first insulating film portion is disposed on the outer surface of the housing 110 and covers the outer surface of the housing 110, which not only protects the housing 110 but also prevents the housing 110 from contacting and conducting with other components. The second insulating film portion is connected to the first insulating film portion and is disposed on the end cap assembly 120.

[0079] See also Figures 3 to 5 , Figure 3 yes Figure 2 The schematic structural diagram of the end cover assembly 120 in the energy storage device 100 is shown. Figure 4 yes Figure 3 The cross-sectional structure diagram of the end cover assembly 120 after being cut along II is shown. Figure 5 yes Figure 2 The exploded structural diagram of the end cap assembly 120 is shown. 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.

[0080] The end cap assembly 120 includes an end cap 10, an explosion-proof valve 20, a protective sheet 30, a lower insulator 40, an upper insulator 50, a pole 60, a riveted pressure ring 70, a sealing ring 80 and a top patch 90. The explosion-proof valve 20 and the protective sheet 30 are both mounted on the end cap 10. Along the thickness direction of the end cap 10, the lower insulator 40 is located on one side of the end cap 10. The upper insulator 50 is mounted on the side of the end cap 10 away from the lower insulator 40. There are two upper insulators 50, namely the negative pole upper insulator 51 and the positive pole upper insulator 52. Along the length direction of the end cap assembly 120, the negative pole upper insulator 51 and the positive pole upper insulator 52 are arranged at intervals. Among them, the negative pole upper insulator 51 is used as the negative pole upper insulator, and the positive pole upper insulator 52 is used as the positive pole upper insulator.

[0081] Along the thickness direction of the end cover assembly 120, the pole 60 passes through the end cover 10, the lower insulating member 40 and the upper insulating member 50. Among them, there are two poles 60, the two poles 60 are respectively the negative pole 61 and the positive pole 62. The negative pole 61 passes through the end cover 10, the lower insulating member 40 and the negative upper insulating member 51. The positive pole 62 passes through the end cover 10, the lower insulating member 40 and the positive upper insulating member 52. The riveted pressure ring 70 is installed on the upper insulating member 50, and is sleeved on the pole 60, and is fixedly connected to the pole 60. There are two riveted pressure rings 70, the two riveted pressure rings 70 are respectively the negative pole pressure block 71 and the positive pole pressure block 72. Among them, the negative pole pressure block 71 is used as the positive pole riveted pressure ring, the negative pole pressure block 71 is installed on the negative upper insulating member 51, and is sleeved on the negative pole 61, and is fixedly connected to the negative pole 61. The positive electrode pressing block 72 is used as a negative electrode riveting pressing ring. The positive electrode pressing block 72 is installed on the positive electrode upper insulating member 52 , and is sleeved on the positive electrode column 62 and fixedly connected to the positive electrode column 62 .

[0082] The sealing ring 80 is mounted on the terminal post 60 and is clamped between the end cap 10 and the terminal post 60. There are two sealing rings 80: a first sealing ring 81 and a second sealing ring 82. The first sealing ring 81 serves as the negative electrode sealing ring and is mounted on the negative terminal post 61 and is clamped between the end cap 10 and the negative terminal post 61. The second sealing ring 82 serves as the positive electrode sealing ring and is mounted on the positive terminal post 62 and is clamped between the end cap 10 and the positive terminal post 62. The top patch 90 is located on the side of the end cap 10 facing away from the lower insulator 40.

[0083] See also Figure 6 and Figure 7 , Figure 6 yes Figure 5 The schematic structural diagram of the end cover 10 in the end cover assembly 120 is shown. Figure 7 yes Figure 6 The cross-sectional structure diagram of the end cover 10 is shown after it is cut along II-II.

[0084] The end cap 10 has a first surface 101 and a second surface 102. Along the thickness direction of the end cap 10 (the Z-axis direction in the figure), the first surface 101 and the second surface 102 are arranged opposite each other. The end cap 10 is provided with an explosion-proof hole 103, a groove 104, an injection hole 105, a first negative electrode column hole 106, and a first positive electrode column hole 107. The explosion-proof hole 103, the injection hole 105, the first negative electrode column hole 106, and the first positive electrode column hole 107 all pass through the first surface 101 and the second surface 102. Specifically, the explosion-proof hole 103 and the groove 104 are both located in the middle of the end cap 10. The opening of the groove 104 is located on the first surface 101. The groove 104 is recessed from the first surface 101 toward the second surface 102, and is arranged around the explosion-proof hole 103 and is connected to the explosion-proof hole 103. The groove 104 has a bottom wall 1041 and a side wall 1042. The groove bottom wall 1041 is disposed opposite to the opening of the groove 104 . The groove side wall 1042 is disposed around the groove bottom wall 1041 and connected between the groove bottom wall 1041 and the first surface 101 .

[0085] The design of the groove 104 can not only prevent the electrolyte and other flowing substances on the end cover 10 from flowing to the protective sheet 30 and contaminating the protective sheet 30 and the explosion-proof valve 20, but also release the welding stress when the explosion-proof valve 20 and the protective sheet 30 are welded to the end cover 10, thereby ensuring the sealing between the explosion-proof valve 20 and the protective sheet 30 and the end cover 10, and ensuring the reliability of the use of the explosion-proof valve 20 and the protective sheet 30.

[0086] The injection hole 105 is located on one side of the explosion-proof hole 103 and the groove 104, and is spaced apart from the explosion-proof hole 103 and the groove 104. The first negative electrode column hole 106 is located on the side of the explosion-proof hole 103 and the groove 104 away from the injection hole 105, and is spaced apart from the explosion-proof hole 103 and the groove 104. The first positive electrode column hole 107 is located on the side of the injection hole 105 away from the explosion-proof hole 103 and the groove 104, and is spaced apart from the injection hole 105. Among them, the distance between the injection hole 105 and the first negative electrode column hole 106 is greater than the distance between the injection hole 105 and the first positive electrode column hole 107. The design of the injection hole 105 close to the first positive electrode column hole 107 can avoid the possibility of the injection hole 105 overlapping with the negative electrode column 61 and causing a short circuit when spraying liquid.

[0087] The end cap 10 is also provided with a raised portion 11, which is provided on the groove bottom wall 1041 and extends from the groove bottom wall 1041 toward the opening of the groove 104, and is spaced apart from the groove side wall 1042, and is also provided around the explosion-proof hole 103. The raised portion 11 has a raised surface 111, a first peripheral surface 112, and a fifth peripheral surface 113. The raised surface 111 is the surface of the raised portion 11 facing away from the groove bottom wall 1041, and is located on the side of the first surface 101 facing the second surface 102, and is spaced apart from the first surface 101 in the thickness direction of the end cap 10. That is, the raised surface 111 is recessed relative to the first surface 101. The distance between the raised surface 111 and the first surface 101 along the thickness direction of the end cap 10 is H. The first circumferential surface 112 is the surface of the protrusion 11 facing the groove side wall 1042, surrounds the protrusion 11, and is connected between the protrusion surface 111 and the groove bottom wall 1041. The fifth circumferential surface 113 is opposite to the first circumferential surface 112 and is flush with the hole wall of the explosion-proof hole 103.

[0088] In addition, the end cap 10 is further provided with an exhaust groove 108, which is located on the side of the raised portion 11 away from the liquid injection hole 105. The opening of the exhaust groove 108 is located on the raised surface 111. The exhaust groove 108 passes through the first circumferential surface 112 and the fifth circumferential surface 113, and is connected to the explosion-proof hole 103 and the groove 104. The exhaust groove 108 not only balances the air pressure in the explosion-proof hole 103 and the groove 104, preventing the air from being trapped between the explosion-proof valve 20 and the protective sheet 30, and preventing the explosion-proof valve 20 and the protective sheet 30 from bulging or sinking due to the internal and external pressure difference caused by altitude, but also, because the exhaust groove 108 is located away from the liquid injection hole 105, it can prevent the electrolyte from entering the explosion-proof hole 103 through the exhaust groove 108 when the liquid injection hole 105 is spraying liquid, thereby preventing the explosion-proof valve 20 from being contaminated by the electrolyte, thereby ensuring the reliability of the explosion-proof valve 20.

[0089] See also Figures 8 to 10 , Figure 8 yes Figure 5 The schematic diagram of the assembly structure of the end cover 10, the explosion-proof valve 20 and the protective sheet 30 in the end cover assembly 120 is shown. Figure 9 yes Figure 8 The schematic diagram of the cross-sectional structure of the assembly structure shown is a diagram after being cut along III-III. Figure 10 yes Figure 5 The protective sheet 30 in the end cover assembly 120 is shown as a schematic structural diagram at another angle.

[0090] 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 experiences thermal runaway, the explosion-proof valve 20 opens, and the high-temperature gas inside the energy storage device 100 is ejected from the explosion-proof hole 103 to prevent the energy storage device 100 from exploding and ensure the reliability of the energy storage device 100.

[0091] The protective sheet 30 is mounted in the groove 104 and covers the explosion-proof hole 103 and the explosion-proof valve 20 to protect the explosion-proof valve 20. Specifically, the protective sheet 30 is mounted on the raised surface 111 and is spaced apart from the groove sidewall surface 1042. The protective sheet 30 has a third surface 301 and a second peripheral surface 302. The third surface 301 is the surface of the protective sheet 30 facing away from the raised surface 111. The third surface 301 is flush with the first surface 101, or is located on the side of the first surface 101 facing the second surface 102. In other words, the third surface 301 does not protrude relative to the first surface 101. This not only prevents the protective sheet 30 from being damaged or falling off due to collisions during the manufacturing or transportation of the energy storage device 100, ensuring that the protective sheet 30 effectively protects the explosion-proof valve 20 and ensures the stability of the explosion-proof valve 20 when opening, but also prevents interference with the top patch 90 when subsequently attached, thereby ensuring the reliability of the protective sheet 30.

[0092] The second circumferential surface 302 is arranged around the third surface 301 and is connected to the third surface 301. Specifically, the second circumferential surface 302 is the surface of the protective sheet 30 facing the groove side wall surface 1042, and is spaced apart from and opposite to the groove side wall surface 1042. The second circumferential surface 302 is flush with the first circumferential surface 112, or the second circumferential surface 302 is located between the first circumferential surface 112 and the groove side wall surface 1042, and is spaced apart from the first circumferential surface 112 and the groove side wall surface 1042. In some other embodiments, the second circumferential surface 302 can also be located on the side of the first circumferential surface 112 away from the groove side wall surface 1042, and is spaced apart from the first circumferential surface 112. In this case, the second circumferential surface 302 can be perpendicular to the raised surface 111.

[0093] In this embodiment, the protective sheet 30 includes a protective layer 31 and an adhesive layer 32. The protective layer 31 is located on the side of the raised surface 111 facing away from the groove bottom wall 1041 and is spaced apart from the raised surface 111. The protective layer 31 has a third surface 301, a fourth surface 311, and a sixth peripheral surface 312. The fourth surface 311 is disposed opposite the third surface 301. The sixth peripheral surface 312 is the surface of the protective layer 31 facing the groove side wall 1042, is spaced apart from the groove side wall 1042, and is connected between the third surface 301 and the fourth surface 311.

[0094] The adhesive layer 32 is located between the protective layer 31 and the raised surface 111, and is bonded between the protective layer 31 and the raised surface 111. Specifically, the adhesive layer 32 is located between the fourth surface 311 and the raised surface 111, and is bonded between the fourth surface 311 and the raised surface 111. The adhesive layer 32 has a third circumferential surface 321 and a fourth circumferential surface 322. The third circumferential surface 321 is the surface of the adhesive layer 32 facing the groove side wall surface 1042, and is spaced apart from the groove side wall surface 1042. The third circumferential surface 321 is flush with the sixth circumferential surface 312, and the second circumferential surface 302 includes the sixth circumferential surface 312 and the third circumferential surface 321. The fourth circumferential surface 322 is disposed opposite to the third circumferential surface 321.

[0095] The protective sheet 30 has a through hole 303 located on the side of the adhesive layer 32 facing away from the liquid injection hole 105. The opening of the through hole 303 is located on the surface of the adhesive layer 32 facing away from the protective layer 31. The through hole 303 extends through the third circumferential surface 321 and the fourth circumferential surface 322, connecting the explosion-proof hole 103 and the groove 104. The through hole 303 is located corresponding to the exhaust groove 108 and is in communication with the exhaust groove 108.

[0096] The through hole 303 not only provides positioning for attaching the protective sheet 30, but also plays the same role as the exhaust groove 108, which can balance the air pressure of the explosion-proof hole 103 and the groove 104, avoid the gas blockage between the explosion-proof valve 20 and the protective sheet 30, and avoid the explosion-proof valve 20 and the protective sheet 30 from bulging or sinking due to the internal and external pressure difference formed by the altitude. Moreover, since the through hole 303 is arranged away from the injection hole 105, it can be avoided that the electrolyte enters the explosion-proof hole 103 from the through hole 303 when the injection hole 105 sprays liquid and contaminates the explosion-proof valve 20, thereby ensuring the reliability of the explosion-proof valve 20.

[0097] See also Figure 11 and Figure 12 , Figure 11 yes Figure 5 The end cap assembly 120 is a schematic diagram of the assembly structure of the end cap 10, the explosion-proof valve 20, the protective sheet 30 and the second insulating film portion 132 of the insulating film. Figure 12 yes Figure 11 The shown assembly structure is a schematic diagram of the cross-sectional structure after being cut along IV-IV.

[0098] The second insulating film portion 132 is provided on the first surface 101 and covers a portion of the groove 104, and is spaced apart from the liquid injection hole 105, the first negative electrode column hole 106, and the first positive electrode column hole 107. The second insulating film portion 132 includes two sub-insulating film portions 133. Along the width direction of the end cap 10, the two sub-insulating film portions 133 are respectively provided on opposite sides of the protective sheet 30, and are spaced apart from the protective sheet 30, and cover opposite ends of the groove 104. Each sub-insulating film portion 133 includes a free end surface 134 facing the protective sheet 30. The orthographic projection of the free end surface 134 on the plane where the groove bottom wall surface 1041 is located is located between the first circumferential surface 112 of the protruding portion 11 and the groove side wall surface 1042, and is spaced apart from the first circumferential surface 112 and the groove side wall surface 1042. The orthographic projection of the free end surface 134 on the plane where the groove bottom wall surface 1041 is located is located between the second circumferential surface 302 of the protection sheet 30 and the groove side wall surface 1042 , and is spaced apart from the second circumferential surface 302 .

[0099] See also Figure 5 、 Figure 13 and Figure 14 , Figure 13 yes Figure 5 The end cap assembly 120 is a schematic diagram of the assembly structure of the end cap 10, the explosion-proof valve 20, the protective sheet 30, the top patch 90 and the second insulating film portion 132 of the insulating film. Figure 14 yes Figure 13 The shown assembly structure is a schematic diagram of the cross-sectional structure after being cut along VV.

[0100] The top patch 90 is provided on the first surface 101 and covers a portion of the groove 104, and covers the injection hole 105 and the second insulating film portion 132. The top patch 90 is provided with a first avoidance hole 901, a second avoidance hole 902, and a third avoidance hole 903. The first avoidance hole 901, the second avoidance hole 902, and the third avoidance hole 903 all penetrate the top patch 90 along the thickness direction of the top patch 90. The first avoidance hole 901 is located in the middle of the top patch 90 and avoids the protective sheet 30. The orthographic projection of the hole wall surface of the first avoidance hole 901 on the plane where the groove bottom wall surface 1041 is located is located between the first circumferential surface 112 of the protrusion 11 and the groove side wall surface 1042, and is spaced apart from both the first circumferential surface 112 and the groove side wall surface 1042. The orthographic projection of the hole wall surface of the first avoidance hole 901 on the plane of the groove bottom wall surface 1041 is located between the second circumferential surface 302 of the protective sheet 30 and the groove side wall surface 1042, and is spaced apart from the second circumferential surface 302 to prevent interference between the top patch 90 and the protective sheet 30 and ensure the assembly stability of the end cap assembly 120. The orthographic projection of the hole wall surface of the first avoidance hole 901 on the plane of the groove bottom wall surface 1041 is located between the orthographic projection of the free end surface 134 on the plane of the groove bottom wall surface 1041 and the groove side wall surface 1042, and is spaced apart from the orthographic projection of the free end surface 134 on the plane of the groove bottom wall surface 1041.

[0101] Because the second insulating film portion 132 partially covers the groove, it improves the adhesion of the top patch 90 to the end cap 10 and reduces the overhanging area of ​​the top patch 90. Furthermore, the protective sheet 30, the second insulating film portion 132, and the top patch 90 all cover the groove 104, reducing the exposed area of ​​the end cap 10 and preventing overlapping contact between the end cap 10 and external components, thereby improving the reliability of the energy storage device 100.

[0102] The second avoidance hole 902 and the third avoidance hole 903 are located on opposite sides of the first avoidance hole 901 and are spaced apart from the first avoidance hole 901. The second avoidance hole 902 is provided in correspondence with the first negative electrode post hole 106 and is used to avoid the negative electrode upper insulating member 51 and the negative electrode pressing block 71. The third avoidance hole 903 is provided in correspondence with the first positive electrode post hole 107 and is used to avoid the positive electrode upper insulating member 52 and the positive electrode pressing block 72.

[0103] Please also refer to Figure 15 , Figure 15 yes Figure 4 An enlarged structural diagram of area A in the end cover assembly 120 is shown.

[0104] The lower insulator 40 is located on the side of the second surface 102 facing away from the first surface 101. The lower insulator 40 includes an explosion-proof fence 41, which is located in the middle of the lower insulator 40 and corresponds to the explosion-proof valve 20. If thermal runaway occurs in the energy storage device 100, high-temperature gases within the energy storage device 100 will pass through the explosion-proof fence 41 and reach the explosion-proof valve 20. After the explosion-proof valve 20 opens, the gases are ejected through the explosion-proof hole 103, ensuring the reliability of the energy storage device 100.

[0105] The lower insulator 40 is provided with a liquid inlet hole 401, a third negative electrode post hole 402, and a third positive electrode post hole 403. The liquid inlet hole 401, the third negative electrode post hole 402, and the third positive electrode post hole 403 all extend through the lower insulator 40 along the thickness direction of the lower insulator 40. The liquid inlet hole 401 is located on one side of the explosion-proof fence 41, spaced apart from the explosion-proof fence 41, and corresponding to the liquid injection hole 105. The third negative electrode post hole 402 is located on the side of the explosion-proof fence 41 facing away from the liquid inlet hole 401, spaced apart from the explosion-proof fence 41, and corresponding to the first negative electrode post hole 106. The third positive electrode post hole 403 is located on the side of the liquid inlet hole 401 facing away from the explosion-proof fence 41, spaced apart from the liquid inlet hole 401, and corresponding to the first positive electrode post hole 107.

[0106] Please also refer to Figure 16 , Figure 16 yes Figure 4 An enlarged structural diagram of area B in the end cover assembly 120 is shown.

[0107] The negative upper insulating member 51 and the positive upper insulating member 52 are arranged on the side of the first surface 101 away from the second surface 102 and are spaced apart from each other. The negative upper insulating member 51 is provided with a second negative post hole 501 which penetrates the negative upper insulating member 51 along the thickness direction of the negative upper insulating member 51 and corresponds to and communicates with the first negative post hole 106. The positive upper insulating member 52 is provided with a second positive post hole 502 which penetrates the positive upper insulating member 52 along the thickness direction of the positive upper insulating member 52 and corresponds to and communicates with the first positive post hole 107. The positive upper insulating member 52 has a resistivity of 1x10 3 ohm / sq to 1x10 10 ohm / sq, so that the positive upper insulating member 52 has weak conductivity. It should be noted that, since the positive upper insulating member 52 has weak conductivity, the positive post 62 is weakly conductively connected between the end cover 10, and therefore, the injection hole 105 will not cause short circuit when it is overlapped with the positive post 62.

[0108] The negative post 61 penetrates the third negative post hole 402, the first negative post hole 106 and the second negative post hole 501. The positive post 62 penetrates the third positive post hole 403, the first positive post hole 107 and the second positive post hole 502. In this embodiment, the negative post 61 and the positive post 62 have the same structure, and next, the structure of the post 60 will be described in detail taking the negative post 61 as an example.

[0109] Please refer to Figure 17 , Figure 17 is Figure 16 the structure diagram of the negative post 61 in the end cover assembly 120 shown in FIG. 12.

[0110] The negative post 61 includes a flange portion 63, a riveting portion 64 and a connecting portion 65. The flange portion 63 is located on the side of the second surface 102 away from the first surface 101. The flange portion 63 is located on the side of the lower insulating member 40 away from the second surface 102. The riveting portion 64 is located on the side of the flange portion 63 facing the end cover 10 and is spaced apart from the flange portion 63 and is used for fixedly connecting the negative pressure block 71. The diameter of the riveting portion 64 is smaller than the diameter of the flange portion 63. The connecting portion 65 is fixedly connected between the flange portion 63 and the riveting portion 64 and penetrates the third negative post hole 402, the first negative post hole 106 and the second negative post hole 501. The diameter of the connecting portion 65 is smaller than the diameter of the flange portion 63 and is larger than the diameter of the riveting portion 64. The connecting portion 65 has a mating surface 651 away from the flange portion 63, the mating surface 651 is arranged around the riveting portion 64 and is connected with the peripheral surface of the riveting portion 64.

[0111] In this embodiment, the riveted portion 64 includes a first portion 66, a second portion 67, and a third portion 68. The first portion 66 is fixedly connected to the connecting portion 65. The diameter of the flange portion 63 is greater than or equal to 1.5 times the diameter of the first portion 66. The second portion 67 is located on the side of the first portion 66 facing away from the connecting portion 65 and is spaced apart from the first portion 66. The diameter of the second portion 67 is greater than the diameter of the first portion 66. The third portion 68 is connected between the first portion 66 and the second portion 67. The diameter of the third portion 68 is greater than the diameter of the first portion 66 and smaller than the diameter of the second portion 67.

[0112] The circumference of the third portion 68 includes a first abutting portion 681, a first chamfered portion 682, and a second chamfered portion 683. The first abutting portion 681 is spaced apart from the circumference of the first portion 66 and the circumference of the second portion 67. The first abutting portion 681 is an inclined surface. The first chamfered portion 682 connects the first abutting portion 681 and the circumference of the first portion 66. The second chamfered portion 683 connects the first abutting portion 681 and the circumference of the second portion 67. Both the first chamfered portion 682 and the second chamfered portion 683 are arcuate surfaces.

[0113] Please also refer to Figure 4 and Figure 5 The negative electrode pressing block 71 is sleeved on the rivet portion 64 of the negative electrode post 61 and fixed by riveting to the rivet portion 64 of the negative electrode post 61. The positive electrode pressing block 72 is sleeved on the rivet portion of the positive electrode post 62 and fixed by riveting to the rivet portion of the positive electrode post 62. It should be noted that in this embodiment, the matching relationship between the negative electrode pressing block 71 and the negative electrode post 61 is the same as the matching relationship between the positive electrode pressing block 72 and the positive electrode post 62. Next, taking the negative electrode pressing block 71 as an example, the matching relationship between the riveted pressing ring 70 and the electrode post 60 will be described in detail.

[0114] Please also refer to Figure 18 , Figure 18 yes Figure 16 Schematic diagram of the structure of the negative electrode pressing block 71 in the end cover assembly 120.

[0115] The negative electrode pressing block 71 has a first mounting surface 701 and a second mounting surface 702. The first mounting surface 701 is the surface of the negative electrode pressing block 71 facing the end cap 10. The second mounting surface 702 is disposed opposite the first mounting surface 701. The negative electrode pressing block 71 is provided with a rivet hole 703, which passes through the first mounting surface 701 and the second mounting surface 702. The structure of the rivet hole 703 is compatible with the structure of the rivet portion 64 of the negative electrode column 61.

[0116] The rivet hole 703 includes a first hole portion 704, a second hole portion 705 and a third hole portion 706. The first hole portion 704 is located on the side of the rivet hole 703 close to the first assembly surface 701. The second hole portion 705 is located on the side of the first hole portion 704 facing the second assembly surface 702, and is spaced apart from the first hole portion 704. The aperture of the second hole portion 705 is larger than the aperture of the first hole portion 704. Exemplarily, the aperture of the second hole portion 705 is greater than or equal to 1.5 times the aperture of the first hole portion 704. The third hole portion 706 is located between the first hole portion 704 and the second hole portion 705, and connects the first hole portion 704 and the second hole portion 705. The aperture of the third hole portion 706 is larger than the aperture of the first hole portion 704 and smaller than the aperture of the second hole portion 705.

[0117] The hole wall surface of the third hole portion 706 includes a second abutting portion 7061, a third chamfered portion 7062, and a fourth chamfered portion 7063. The second abutting portion 7061 is spaced apart from the hole wall surface of the first hole portion 704 and the hole wall surface of the second hole portion 705. The second abutting portion 7061 is an inclined surface. The third chamfered portion 7062 connects the second abutting portion 7061 and the hole wall surface of the first hole portion 704. The fourth chamfered portion 7063 connects the second abutting portion 7061 and the hole wall surface of the second hole portion 705. Both the third chamfered portion 7062 and the fourth chamfered portion 7063 are arcuate surfaces.

[0118] Please also refer to Figure 16 , the rivet portion 64 of the negative electrode column 61 is connected and matched with the rivet hole 703 of the negative electrode pressure block 71. Among them, the rivet portion 64 of the negative electrode column 61 is riveted and matched with the rivet hole 703 of the negative electrode pressure block 71. Specifically, the matching surface 651 of the connecting portion 65 is interconnected with the first assembly surface 701 of the negative electrode pressure block 71, the first portion 66 is connected and matched with the first hole portion 704, the circumference of the first portion 66 is connected with the hole wall surface of the first hole portion 704, the second portion 67 is connected and matched with the second hole portion 705, the circumference of the second portion 67 is connected with the hole wall surface of the second hole portion 705, the third portion 68 is connected and matched with the third hole portion 706, and the circumference of the third portion 68 is connected with the hole wall surface of the third hole portion 706. The first abutting portion 681 is connected to the second abutting portion 7061 , the first chamfered portion 682 is connected to the third chamfered portion 7062 , and the second chamfered portion 683 is connected to the fourth chamfered portion 7063 .

[0119] It should be noted that the diameter of the flange portion 63 of the negative electrode column 61 is larger than the diameters of the rivet portion 64 and the connection portion 65. This can better ensure that the rivet portion 64 expands during the riveting assembly of the negative electrode column 61 and the negative electrode pressing block 71, thereby ensuring the riveting strength between the negative electrode column 61 and the negative electrode pressing block 71. Moreover, the larger diameter of the flange portion 63 can improve the pressure resistance of the negative electrode column 61, preventing the flange portion 63 from significantly expanding and deforming during the riveting process, thereby ensuring the dimensional stability of the connection portion 65 and preventing the thickness of the connection portion 65 from being reduced due to riveting. This ensures that the creepage distance and electrical clearance of the negative electrode column 61 are not compressed, thereby ensuring the safe use of the energy storage device 100. Furthermore, because the diameter of the flange portion 63 is greater than or equal to 1.5 times the diameter of the first portion 66 , the mating surface 651 of the connecting portion 65 abuts the first assembly surface 701 of the negative electrode pressing block 71 , thereby ensuring that the diameter of the flange portion 63 is sufficiently large. This can increase the effective flow area of ​​the end cap assembly 120 , reduce the internal resistance of the energy storage device 100 , improve the flow effect of the end cap assembly 120 , and thereby improve the energy efficiency of the energy storage device 100 .

[0120] In addition, the aperture of the second hole portion 705 is greater than or equal to 1.5 times the aperture of the first hole portion 704, which can ensure that during the riveting process of the negative electrode column 61 and the negative electrode pressure block 71, the rivet portion 64 can effectively expand and cooperate with the rivet hole 703 for fixation. This not only ensures the expansion amount and riveting strength of the rivet portion 64, but also facilitates the formation of an inclined surface between the first abutting portion 681 and the second abutting portion 7061, thereby improving the flow capacity of the end cover assembly 120 and improving the energy efficiency of the energy storage device 100.

[0121] The first sealing ring 81 is disposed through the first negative electrode post hole 106 and is sleeved over the connection portion 65 of the negative electrode post 61. It is clamped between the flange portion 63 of the negative electrode post 61 and the end cap 10. This not only prevents the negative electrode post 61 and the end cap 10 from direct contact and short circuit, but also seals the gap between the negative electrode post 61 and the end cap 10, ensuring the sealing reliability of the end cap assembly 120. The second sealing ring 82 is disposed through the first positive electrode post hole 107 and is sleeved over the connection portion of the positive electrode post 62. It is clamped between the flange portion of the positive electrode post 62 and the end cap 10. This not only prevents the positive electrode post 62 and the end cap 10 from direct contact and short circuit, but also seals the gap between the positive electrode post 62 and the end cap 10, ensuring the sealing reliability of the end cap assembly 120.

[0122] In the end cap assembly 120 shown in this application, the protective sheet 30 does not protrude relative to the first surface 101 of the end cap 10. This not only prevents the protective sheet 30 from being damaged or falling off due to bumps during the manufacturing or transportation of the energy storage device 100, but also prevents interference with the top patch 90 during subsequent attachment, thereby ensuring the reliability of the protective sheet 30. Furthermore, the protective sheet 30 and the top patch 90 cover the groove 104, reducing the exposed area of ​​the end cap 10 and preventing short circuits caused by contact between the end cap 10 and external components, thereby ensuring the reliability of the energy storage device 100.

[0123] 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.

[0124] The above description is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application; the embodiments of this application and the features of the embodiments can be combined with each other unless there is a conflict. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An end cap assembly for an energy storage device, characterized in that: Including end cover, explosion-proof valve, protection sheet and top patch; 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 a groove. The explosion-proof hole passes through the first surface and the second surface. The opening of the groove is located on the first surface. The groove is arranged around the explosion-proof hole. The groove has a groove bottom wall surface and a groove side wall surface. The groove side wall surface is arranged around the groove bottom wall surface and is connected to the groove bottom wall surface. The end cover is further provided with a raised portion, which is provided on the bottom wall of the groove, surrounds the explosion-proof hole, and is spaced apart from the side wall of the groove. The raised portion has a raised surface and a first peripheral surface. The raised surface is the surface of the raised portion facing away from the bottom wall of the groove, and is located on the side of the first surface facing the bottom wall of the groove, and is spaced apart from the first surface in the thickness direction of the end cover. The first peripheral surface is the surface of the raised portion facing the side wall of the groove, surrounds the raised portion, and is connected between the bottom wall of the groove and the raised surface. The explosion-proof valve is installed on the end cover and covers the opening of the explosion-proof hole on the second surface; The protective sheet is mounted on the raised surface and covers the explosion-proof hole. The protective sheet has a third surface and a second peripheral surface. The third surface is the surface of the protective sheet facing away from the raised portion. The third surface is located on the side of the first surface facing the second surface. The second peripheral surface is arranged around the third surface and connected to the third surface. The second peripheral surface is spaced apart from and opposite to the groove side wall. The orthographic projection of the second peripheral surface on the plane where the groove bottom wall is located is located between the first peripheral surface and the groove side wall. The top patch is installed on the first surface, and the top patch is provided with a first avoidance hole. The first avoidance hole penetrates the top patch along the thickness direction of the top patch and avoids the protective sheet. The orthographic projection of the hole wall of the first avoidance hole on the plane where the bottom wall of the groove is located is located between the orthographic projection of the second circumferential surface on the plane where the bottom wall of the groove is located and the side wall of the groove.

2. The end cap assembly according to claim 1, wherein: The end cap is further provided with a liquid injection hole, which is spaced apart from the groove and passes through the first surface and the second surface; The protective sheet includes a protective layer and an adhesive layer, the protective layer is located on the side of the raised surface away from the bottom wall of the groove, the adhesive layer is located between the protective layer and the raised surface, the adhesive layer has a third circumferential surface and a fourth circumferential surface, the third circumferential surface is the surface of the adhesive layer facing the side wall of the groove, the fourth circumferential surface is arranged opposite to the third circumferential surface, the adhesive layer is provided with a through hole, the through hole is located on the side of the adhesive layer away from the injection hole, and passes through the third circumferential surface and the fourth circumferential surface.

3. The end cap assembly according to claim 2, wherein: The raised portion further has a fifth peripheral surface, which is disposed opposite to the first peripheral surface and connected to the raised surface; The end cover is further provided with an exhaust groove, which is located on a side of the raised portion away from the liquid injection hole. The exhaust groove passes through the raised surface, the first peripheral surface and the fifth peripheral surface, and is arranged corresponding to the through hole.

4. The end cap assembly according to claim 2, wherein: The end cap is further provided with a first negative electrode post hole and a first positive electrode post hole, wherein the first negative electrode post hole and the first positive electrode post hole both penetrate the first surface and the second surface and are spaced apart from the groove and the liquid injection hole, wherein the distance between the liquid injection hole and the first negative electrode post hole is greater than the distance between the liquid injection hole and the first positive electrode post hole; The end cap assembly further includes a negative electrode upper insulating member, a positive electrode upper insulating member, a positive electrode column, a negative electrode column, a negative electrode pressing block and a positive electrode pressing block; The negative electrode upper insulating member and the positive electrode upper insulating member are both provided on a side of the first surface away from the second surface and are spaced apart from each other. The negative electrode upper insulating member is provided with a second negative electrode post hole, which passes through the negative electrode upper insulating member along the thickness direction of the negative electrode upper insulating member and is communicated with the first negative electrode post hole. The positive electrode upper insulating member is provided with a second positive electrode post hole, which passes through the positive electrode upper insulating member along the thickness direction of the positive electrode upper insulating member and is communicated with the first positive electrode post hole. The resistivity of the positive electrode upper insulating member is 1×10 3 ohm / sq to 1×10 10 between ohm / sq; The negative electrode post is inserted into the first negative electrode post hole and the second negative electrode post hole, and the positive electrode post is inserted into the first positive electrode post hole and the second positive electrode post hole; The negative electrode pressing block is installed on the negative electrode upper insulating member, and is sleeved on the negative electrode column and fixedly connected to the negative electrode column. The positive electrode pressing block is installed on the positive electrode upper insulating member, and is sleeved on the positive electrode column and fixedly connected to the positive electrode column.

5. The end cap assembly according to claim 4, wherein: The negative electrode pressing block has a first assembly surface and a second assembly surface, the first assembly surface is the surface of the negative electrode pressing block facing the end cover, and the second assembly surface is arranged opposite to the first assembly surface. The negative electrode pressing block is provided with a rivet hole, and the rivet hole passes through the first assembly surface and the second assembly surface; The negative electrode column includes a flange portion, a rivet portion and a connecting portion. The flange portion is located on the side of the second surface facing away from the first surface. The rivet portion is located on one side of the flange portion and is spaced apart from the flange portion and is connected and matched with the rivet hole. The connecting portion is fixedly connected between the flange portion and the rivet portion and is passed through the first positive electrode column hole and the second positive electrode column hole. The connecting portion has a mating surface facing away from the flange portion, and the mating surface is connected to the first assembly surface.

6. The end cap assembly according to claim 5, wherein: The rivet hole includes a first hole portion, a second hole portion, and a third hole portion, wherein the second hole portion is located on a side of the first hole portion away from the end cover and is spaced apart from the first hole portion, and the third hole portion communicates with the first hole portion and the second hole portion, wherein a diameter of the third hole portion is larger than a diameter of the first hole portion and smaller than a diameter of the second hole portion; The riveted portion includes a first part, a second part and a third part. The first part is fixedly connected to the connecting portion and is connected and matched with the first hole portion. The circumferential surface of the first part is connected to the hole wall surface of the first hole portion. The second part is located on the side of the first part away from the connecting portion and is connected and matched with the second hole portion. The circumferential surface of the second part is connected to the hole wall surface of the second hole portion. The third part is fixedly connected between the first and third parts and is connected and matched with the third hole portion. The circumferential surface of the third part is connected to the hole wall surface of the third hole portion. The diameter of the third part is larger than the diameter of the first part and smaller than the diameter of the second part.

7. The end cap assembly according to claim 6, wherein: The diameter of the flange portion is greater than or equal to 1.5 times the diameter of the first portion.

8. The end cap assembly according to claim 6, wherein: The diameter of the first hole portion is greater than or equal to 1.5 times the diameter of the third hole portion.

9. 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 8, 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.

10. The energy storage device according to claim 9, characterized in that: The energy storage device also includes an insulating film, which includes a first insulating film portion and a second insulating film portion. The first insulating film portion covers the outer surface of the shell, and the second insulating film portion is connected to the first insulating film portion and is arranged on the first surface and covers part of the groove. The end cover assembly also includes a top patch, which is installed on the first surface and covers the second insulating film portion.

11. The energy storage device according to claim 10, characterized in that: The second insulating film portion includes two sub-insulating film portions. Along the width direction of the end cover, the two sub-insulating film portions are respectively arranged on opposite sides of the protection sheet, spaced apart from the protection sheet, and cover opposite ends of the groove.

12. An electrical device, characterized in that: It comprises the energy storage device according to any one of claims 9 to 11, wherein the energy storage device supplies power to the electrical equipment.

Images