End cap assembly, energy storage device, and power supply system

Abstract

The application discloses an end cover assembly, an energy storage device and a power supply system, and relates to the technical field of energy storage. The end cover assembly comprises a cover plate, an explosion-proof hole is arranged in the cover plate, and an explosion-proof valve is arranged in the explosion-proof hole; an insulating piece is arranged on the first side of the cover plate in the thickness direction; an electrode terminal is arranged through the cover plate and the insulating piece; an adapter is arranged on the side of the insulating piece away from the cover plate, and the adapter comprises a first connecting part and a second connecting part, and the distance between the surface of the first connecting part away from the insulating piece and the cover plate is smaller than the distance between the surface of the second connecting part away from the insulating piece and the cover plate. In the application, the reliable support of the electrode assembly can be realized based on the second connecting part, so that, after the insulating piece is melted, the gas running gap communicated with the explosion-proof hole is formed between the electrode assembly and the cover plate, and the gas running channel communicated with the gas running gap is formed between the first connecting part and the electrode assembly, so that the reliability of the gas exhaust is ensured, and the safety hidden danger of the energy storage device in the thermal runaway is reduced.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and more specifically, to an end cap assembly, an energy storage device, and a power supply system. Background Technology

[0002] A rechargeable battery, also known as a rechargeable battery or storage battery, is a battery that can be recharged after being discharged to reactivate its active materials and continue to be used. The recyclable nature of rechargeable batteries has made them a primary power source for electrical devices. As the demand for rechargeable batteries increases, people are placing higher demands on their performance in various aspects, especially their lifespan.

[0003] In related technologies, secondary batteries typically consist of an end cap assembly, an electrode assembly, and a housing. The actual production process involves fabricating the end cap assembly, electrode assembly, and housing separately. Then, metal adapters are used to weld the electrode posts of the end cap assembly and the tabs of the electrode assembly together. The electrode assembly is then placed inside the housing, and the end cap assembly is used to close the opening of the housing and welded shut to form the basic structure of the secondary battery. Afterward, electrolyte is manually injected through injection holes located on the end cap assembly, and these injection holes are then welded shut to seal the battery.

[0004] The end cap assembly includes a cover plate and a lower plastic layer, as well as electrode terminals passing through the cover plate and the lower plastic layer. The cover plate has explosion-proof holes. One end of the electrode terminal is electrically connected to the motor assembly, while the other end is exposed on the side of the cover plate away from the lower plastic layer. In the event of thermal runaway in the energy storage device, the lower plastic layer is prone to melting due to high temperatures. At this time, the generated gas from the electrode assembly rises and blocks the explosion-proof holes on the cover plate, affecting the venting of gas from the casing and increasing the safety hazard of an explosion in the energy storage device. Utility Model Content

[0005] A primary objective of this application is to provide an end cap assembly, energy storage device, and power supply system that improve safety during thermal runaway.

[0006] To achieve the above-mentioned objectives, this application adopts the following technical solution: According to one aspect of this application, an end cap assembly is provided, comprising: a cover plate, the cover plate being rectangular and having an explosion-proof hole, wherein an explosion-proof valve is disposed within the explosion-proof hole; an insulating member located on a first side of the cover plate in the thickness direction; an electrode terminal passing through the cover plate and the insulating member, and having a first end and a second end, the first end being located on the first side of the cover plate, and the second end being exposed on the second side of the cover plate in the thickness direction; and an adapter member located on the side of the insulating member facing away from the cover plate, and having a first connecting portion and a second connecting portion distributed along the width direction of the cover plate, the first connecting portion being fixedly connected to the first end, the second connecting portion being used for electrical connection with the electrode assembly, and the distance between the surface of the first connecting portion facing away from the insulating member and the cover plate being less than the distance between the surface of the second connecting portion facing away from the insulating member and the cover plate.

[0007] In this embodiment, the distance between the surface of the first connecting part away from the insulating part and the cover plate on the adapter is smaller than the distance between the surface of the second connecting part away from the insulating part and the cover plate. This allows for reliable support of the electrode assembly based on the second connecting part after the insulating part melts. As a result, after the insulating part melts, a gas venting gap communicating with the explosion-proof hole is formed between the electrode assembly and the cover plate. At the same time, a gas venting channel communicating with the gas venting gap is formed between the first connecting part and the electrode assembly, thereby ensuring the reliability of gas discharge and reducing the safety hazard of the energy storage device exploding during thermal runaway.

[0008] According to one embodiment of this application, the adapter is a flat plate structure, and the thickness of the first connecting portion is less than the thickness of the second connecting portion.

[0009] In this embodiment, the thickened second connecting portion allows for greater welding power when welding the electrode assembly to the second connecting portion, ensuring the welding effect between the electrode assembly and the second connecting portion and improving the welding yield. At the same time, the thickened second connecting portion can provide a larger current-carrying cross section, thereby reducing the temperature rise of the second connecting portion during charging and discharging.

[0010] According to one embodiment of this application, the size of the second connecting portion is larger than the size of the first connecting portion in the length direction of the cover plate.

[0011] In this embodiment, the large-sized second connecting portion increases the support area for the electrode assembly, thereby ensuring the support effect for the electrode assembly and ensuring the air venting gap formed between the electrode assembly and the cover plate after the insulating component melts. In addition, the large-sized second connecting portion facilitates the increase of the electrical connection area between the second connecting portion and the tab, thereby reducing the temperature rise of the second connecting portion during charging and discharging.

[0012] According to one embodiment of this application, the insulating member has a venting area, the venting area has a venting hole communicating with the explosion-proof hole, and the second connecting portion and the venting area are spaced apart in the length direction of the cover plate.

[0013] According to one embodiment of this application, the adapter has two second connecting portions located on both sides of the first connecting portion in the width direction of the cover plate.

[0014] According to one embodiment of this application, the end cap assembly further includes a heat insulation sheet located between the second connecting portion and the insulating member.

[0015] In this embodiment, by setting the heat insulation sheet, the welding heat can be avoided from being conducted to the insulating component during the welding of the second connection part and the electrode tab, causing the insulating component to soften locally or even melt through, thereby ensuring the manufacturing yield of the insulating component and thus ensuring the reliability of the electrical isolation of the cover plate.

[0016] According to one embodiment of this application, the first connecting portion has a through hole, the first end portion extends into the through hole and is fixedly connected to the edge of the opening of the through hole; a protective film is provided on the surface of the first connecting portion facing away from the insulating member, and the protective film covers the edge of the opening of the through hole.

[0017] In this embodiment, the weld marks between the first connection and the first end are covered by a protective film to prevent weld slag from falling off and piercing the diaphragm included in the electrode assembly, thus causing an electrical short circuit.

[0018] According to one embodiment of this application, the insulating member has a positioning protrusion facing away from the cover plate; The adapter has the positioning protrusion on at least one side of the cover plate in the length direction and / or width direction, and the edge of the adapter abuts against the positioning protrusion.

[0019] In this embodiment, the positioning protrusion on the insulating part facing away from the cover plate facilitates the positioning and assembly of the adapter, thereby improving the assembly efficiency of the end cover assembly.

[0020] According to one aspect of this application, an energy storage device is provided, comprising: a housing including a receiving cavity with an opening; an electrode assembly housed within the receiving cavity; and an end cap assembly as described in the preceding aspect, the end cap assembly sealing the opening of the receiving cavity.

[0021] According to one embodiment of this application, the electrode assembly has a tab facing the end cap assembly; the tab is electrically connected to the second connecting portion, and the size of the tab is larger than the size of the second connecting portion in the length direction of the cover plate.

[0022] In this embodiment, the coverage area of ​​the electrode tab over the second connection portion is guaranteed, thereby guaranteeing the electrical connection area between the electrode tab and the second connection portion, and thus ensuring the reliability of the electrical connection between the electrode tab and the second connection portion, while also guaranteeing the overcurrent capability between the electrode assembly and the adapter.

[0023] According to one embodiment of this application, the orthographic projection of the second connecting portion on the cover plate is located within the orthographic projection of the electrode tab on the cover plate.

[0024] In this embodiment, the tabs of the electrode assembly are provided to fully cover the second connection portion, so as to ensure the electrical connection area and the supporting effect of the second connection portion on the electrode assembly after the insulating component melts.

[0025] According to one embodiment of this application, the insulating member has a venting area, and the tabs and the venting area are spaced apart in the length direction of the cover plate.

[0026] In this embodiment, a gap exists between the tab of the electrode assembly and the vent area on the insulating component to prevent the corner of the tab from extending into the vent hole, which would cause the tab to be electrically connected to the cover plate through the explosion-proof valve, thereby ensuring the reliability of the cover plate's insulation.

[0027] According to one aspect of this application, a power supply system is provided, the power supply system including electrical equipment and the energy storage device described in the above aspect, the energy storage device supplying power to the electrical equipment.

[0028] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0029] The above and other features and advantages of this application will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0030] Figure 1 This is a schematic diagram of an energy storage system according to an exemplary embodiment.

[0031] Figure 2 This is a schematic diagram of the axial exploded structure of an energy storage device according to an exemplary embodiment.

[0032] Figure 3 This is a schematic diagram of the axial structure of an end cap assembly according to an exemplary embodiment.

[0033] Figure 4 This is a schematic diagram of the axial exploded structure of an end cap assembly according to an exemplary embodiment.

[0034] Figure 5 This is a schematic diagram of the axial structure of an end cap assembly electrical connection according to an exemplary embodiment.

[0035] Figure 6 yes Figure 5 The diagram shows a partially enlarged structural feature.

[0036] Figure 7 This is a schematic diagram of the axial structure of another end cap assembly according to an exemplary embodiment.

[0037] Figure 8 This is a schematic diagram of a power supply system according to an exemplary embodiment.

[0038] The reference numerals in the attached figures are explained as follows: 1000. Energy storage system; 100. Energy storage device; 200. Power conversion device; 300. First user load; 400. Second user load; 500. Power supply system; 510. Electrical equipment; 10. Housing; 20. Electrode assembly; 30. End cap assembly; 11. Receiving cavity; 31. Cover plate; 32. Insulating component; 33. Electrode terminal; 34. Adapter; 35. Explosion-proof valve; 36. Heat insulation sheet; 311. Explosion-proof hole; 312. Liquid injection hole; 321. Ventilation area; 322. Ventilation holes; 323. Positioning protrusion; 331. First end; 332. Second end; 341. First connecting part; 342. Second connecting part; 343. Protrusion; 344. Protective film; 345. Through hole; 21. Core; 22. Electrode. Detailed Implementation

[0039] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0040] Because the energy people need is highly time- and space-dependent, in order to make rational use of energy and improve energy efficiency, it is necessary to use a medium or device to store one form of energy in the same way or by converting it into another form of energy, and then release it in a specific form of energy based on future application needs.

[0041] Currently, the generation of green electricity generally relies on solar, wind, and hydropower. However, wind and solar power are generally characterized by strong intermittency and large fluctuations, which can cause grid instability, insufficient power during peak demand periods, and excessive power during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar curtailment." Solving these problems requires energy storage. This involves converting electrical energy into other forms of energy through physical or chemical means and storing it. When needed, this energy can be converted back into electrical energy and released. Simply put, energy storage is like a large "power bank," storing electrical energy when solar and wind power are abundant and releasing the stored electricity when needed.

[0042] 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 set of chemical batteries, which mainly use the chemical elements in the chemical batteries as energy storage media. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage media. Simply put, the electrical energy generated by wind and solar energy is stored in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electricity is released for use, or transferred to places with a shortage of electricity for use.

[0043] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, and consumption-side energy storage. The corresponding types of energy storage devices include: (1) Large-scale energy storage power stations (including prefabricated energy storage modules) applied to wind power and photovoltaic power stations can help renewable energy power generation meet grid connection requirements and improve the utilization rate of renewable energy. As a high-quality active / reactive power regulation power source on the power supply side, energy storage power stations can achieve load matching of power in time and space, enhance the absorption capacity of renewable energy, reduce instantaneous power changes, reduce the impact on the power grid, improve the absorption of new energy power generation, and are of great significance in power grid system backup, alleviating peak load power supply pressure and peak regulation and frequency regulation. (2) The energy storage prefabricated cabin applied on the grid side mainly functions as peak regulation, frequency regulation and grid congestion relief. In terms of peak regulation, it can realize peak shaving and valley filling of electricity load, that is, charging the energy storage device when the electricity load is low and releasing the stored electricity during the peak period of electricity load, thereby achieving a balance between power production and consumption. (3) Small energy storage cabinets applied to the electricity consumption side mainly function as self-consumption of electricity, peak-valley price arbitrage, capacity cost management, and improvement of power supply reliability. Depending on the application scenario, electricity consumption side energy storage can be divided into industrial and commercial energy storage cabinets, household energy storage devices, energy storage charging piles, etc., which are generally used in conjunction with distributed photovoltaics. Industrial and commercial users can use energy storage for peak-valley price arbitrage and capacity cost management. In the electricity market implementing peak-valley pricing, by charging the energy storage system when the electricity price is low and discharging the energy storage system when the electricity price is high, peak-valley price arbitrage can be achieved, reducing electricity costs. In addition, industrial enterprises subject to two-part tariffs can use energy storage systems to store energy during off-peak hours and discharge during peak loads, thereby reducing peak power and the maximum demand declared, achieving the goal of reducing capacity costs. Household photovoltaics with energy storage can improve the level of self-consumption of electricity. Due to high electricity prices and poor power supply stability, the demand for household photovoltaic installations is driven. Given that photovoltaic power generation occurs during the day, while user load is generally higher at night, configuring energy storage can better utilize photovoltaic power, improve self-consumption levels, and reduce electricity costs. Furthermore, energy storage is needed in areas such as communication base stations and data centers for backup power.

[0044] Figure 1 This is a schematic diagram of the structure of an energy storage system 1000 provided in this application. The energy storage system 1000 is illustrated using a shared energy storage scenario on the generation / distribution side as an example. Of course, the energy storage device 100 of this application is not limited to the shared energy storage scenario on the generation / distribution side.

[0045] like Figure 1 As shown, the energy storage system 1000 includes: an energy storage device 100, a first power conversion device 200, a second power conversion device 200, and a high-voltage cable.

[0046] In some embodiments of the power generation scenario, the first power conversion device 200 can be a wind power conversion device 200. Since the electricity generated by wind power conversion is volatile, random, and intermittent, the unstable electricity output by the wind power conversion device 200 can be stored in an energy storage device 100 via grid connection. The energy storage device 100 is connected to a high-voltage cable and outputs smooth electricity to the power consumption side, achieving peak shaving and frequency regulation, and ensuring stable grid operation. Alternatively, the wind power conversion device 200 is always connected to the high-voltage cable, and under normal power generation conditions, the electricity is converted through the high-voltage cable... The wind power conversion device 200 outputs electricity to the power consumption side. When the current power load is low and the wind power conversion device 200 generates excess electricity, the excess electricity is first stored in the energy storage device 100 to improve the problem of new energy power generation and consumption. When the power load is high, the power grid issues an instruction to transmit the electricity stored in the energy storage device 100 together with the high-voltage cable in grid-connected mode to supply electricity to the power consumption side. This provides the power grid with various services such as peak shaving, frequency regulation, and backup, giving full play to the peak shaving role of the power grid, promoting peak shaving and valley filling, and alleviating the power supply pressure of the power grid.

[0047] In some embodiments on the distribution network side, the second power conversion device 200 can be a photovoltaic power conversion device 200. The energy storage device 100 is connected to the photovoltaic power conversion device 200 and installed downstream of the high-voltage cable between the user load. The electrical energy output by the photovoltaic power conversion device 200 is stored in the energy storage device 100, which can respond in a timely manner to act as a backup power source when the power grid / distribution network fails. Alternatively, it can provide power supply support to alleviate line congestion when the high-voltage cable transmission line is blocked, and to delay the economic pressure caused by the expansion of the power grid / distribution capacity when the power grid is planned to be expanded.

[0048] Optionally, the first power conversion device 200 may include, but is not limited to, a wind power conversion device, and the second power conversion device 200 may include, but is not limited to, a photovoltaic panel. The first power conversion device 200 and the second power conversion device 200 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy and mechanical energy into electrical energy.

[0049] Optionally, the energy storage device 100 can be used in, but is not limited to, 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 is also applied in multiple fields such as data centers, military equipment, aerospace, charging piles, and electric vehicles.

[0050] Optionally, the energy storage device 100 may include, but is not limited to, individual battery cells, as well as battery modules, battery packs, battery clusters, energy storage cabinets / prefabricated energy storage compartments, and other battery integrated systems composed of individual battery cells. The actual application form of the energy storage device 100 provided in this application embodiment may be, but is not limited to, the listed products, and may also be other application forms. This application embodiment does not strictly limit the application form of the energy storage device 100.

[0051] Optionally, the battery cell is not limited to at least one of square, prismatic, or other shaped batteries. The battery cell can be a rechargeable battery, meaning a battery cell that can be recharged after discharge to activate its active materials and continue to be used. The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application does not specifically limit its type.

[0052] In some implementations, such as Figure 2 As shown, the energy storage device 100 includes: a housing 10, an electrode assembly 20, and an end cap assembly 30. The housing 10 includes a receiving cavity 11 with an opening. The electrode assembly 20 is housed in the receiving cavity 11, and the end cap assembly 30 seals the opening of the receiving cavity 11.

[0053] The housing 10 can be a cylindrical structure with one end open. In this case, the energy storage device 100 includes an end cap assembly 30 to seal one opening of the housing 10. Alternatively, the housing 10 can be a cylindrical structure with both ends open. In this case, the energy storage device 100 includes an end cap assembly 30 and a base plate, or includes two end cap assemblies 30, so that the two openings of the housing 10 can be sealed by one end cap assembly 30 and a base plate, or by two end cap assemblies 30 respectively.

[0054] Among them, such as Figure 2 As shown, the electrode assembly 20 is mainly composed of a core 21, and may include one core 21 or multiple cores 21; the core 21 includes a first electrode sheet, a second electrode sheet, and a separator stacked together, the first electrode sheet and the second electrode sheet having opposite polarities (for example, one is a positive electrode sheet and the other is a negative electrode sheet), and the separator is located between the first electrode sheet and the second electrode sheet; Figure 2 As shown, the end of the core 21 has a tab 22, such as a first tab formed at the edge of the first pole piece and a second tab formed at the edge of the second pole piece. The first tab and the second tab can be located at the same end of the core 21 (e.g., the end facing the end cap assembly 30) or at different ends of the core 21 (e.g., the end facing the end cap assembly 30 and the end away from the end cap assembly 30).

[0055] Among them, such as Figure 2As shown, the end cap assembly 30 includes a cover plate 31 (such as a light aluminum sheet), an insulating component 32 (such as a lower plastic sheet), and electrode terminals 33. The insulating component 32 is fitted to the surface of the cover plate 31 facing the electrode assembly 20. The electrode terminals 33 pass through the insulating component 32 and the cover plate 31 and are connected to the electrode assembly 20. Additionally, as... Figure 2 As shown, an explosion-proof valve 35 can be installed on the cover plate 31. The explosion-proof valve 35 is used to open when the pressure inside the receiving cavity 11 is greater than the valve opening pressure, and to release the gas inside the receiving cavity 11, thereby improving the safety of the energy storage device 100. Furthermore, as Figure 2 As shown, an injection hole 312 can also be provided on the cover plate 31 so that after the energy storage device 100 completes the assembly of the basic structure, electrolyte can be injected along the injection hole 312 to wet the electrode assembly 20.

[0056] Taking the first electrode and the second electrode as an example located at the end of the electrode assembly 20 facing the end cap assembly 30, the end cap assembly 30 includes two electrode terminals 33 passing through the insulating member 32 and the cover plate 31. The two electrode terminals 33 are respectively connected to the first electrode and the second electrode to realize the output of electrical energy of the electrode assembly 20 through the two electrode terminals 33.

[0057] In related technologies, the lower plastic portion of the end cap assembly 30 provides electrical insulation between the electrode assembly 20 and the cover plate 31. However, in the event of thermal runaway in the energy storage device 100, the generated high temperature can easily exceed the melting point of the lower plastic, causing it to melt. At this time, the electrode assembly 20 is prone to floating towards the cover plate 31 due to the gas generated inside it, blocking the explosion-proof hole 311 of the explosion-proof valve 35 on the cover plate 31. This prevents the gas accumulated in the containment cavity 11 from being effectively discharged, thereby increasing the safety hazard of the energy storage device 100 exploding.

[0058] Figure 3 An axial side view of an end cap assembly 30 provided in an embodiment of this application is illustrated. Figure 4 An exploded structural diagram of an end cap assembly 30 provided in an embodiment of this application is illustrated. Figure 2 , Figure 3 and Figure 4As shown, the end cap assembly 30 includes: a cover plate 31, an insulating member 32, an electrode terminal 33, and an adapter 34. The cover plate 31 is rectangular and has an explosion-proof hole 311, in which an explosion-proof valve 35 is disposed. The insulating member 32 is located on the first side of the cover plate 31 in the thickness direction S. The electrode terminal 33 passes through the cover plate 31 and the insulating member 32, and has a first end 331 and a second end 332. The first end 331 is located on the first side of the cover plate 31 (i.e., the side of the cover plate 31 closer to the insulating member 32 in the thickness direction S), and the second end 332 is exposed on the cover plate 31 in the thickness direction S. The second side in the degree direction S (i.e., the side away from the insulating member 32 in the thickness direction S of the cover plate 31); the adapter 34 is located on the side of the insulating member 32 away from the cover plate 31, and has a first connecting portion 341 and a second connecting portion 342 distributed along the width direction Y of the cover plate 31. The first connecting portion 341 is fixedly connected to the first end 331, and the second connecting portion 342 is used for electrical connection with the electrode assembly 20. The distance between the surface of the first connecting portion 341 away from the insulating member 32 and the cover plate 31 is smaller than the distance between the surface of the second connecting portion 342 away from the insulating member 32 and the cover plate 31.

[0059] In this embodiment, the distance between the surface of the first connecting part 341 facing away from the insulating member 32 and the cover plate 31 on the adapter 34 is smaller than the distance between the surface of the second connecting part 342 facing away from the insulating member 32 and the cover plate 31. The electrode assembly 20 can be reliably supported based on the second connecting part 342. After the insulating member 32 melts, a gas venting gap communicating with the explosion-proof hole 311 is formed between the electrode assembly 20 and the cover plate 31. At the same time, a gas venting channel communicating with the gas venting gap is formed between the first connecting part 341 and the electrode assembly 20. This ensures the reliability of gas discharge from the accommodating cavity 11 and reduces the safety hazard of the energy storage device 100 exploding during thermal runaway.

[0060] The surface of the cover plate 31 facing the insulating member 32 is a flat structure, or at least the area of ​​the orthogonal projection of the adapter 34 on the surface of the cover plate 31 facing the insulating member 32 is a flat structure, so as to ensure that after the insulating member 32 melts, the surface of the second connecting part 342 away from the cover plate 31 protrudes from the surface of the first connecting part 341 away from the cover plate 31, thereby ensuring reliable support for the electrode assembly 20 and ensuring the airflow conduction effect of the air passage.

[0061] The adapter 34 includes a first connecting portion 341 and a second connecting portion 342, which can be an integral structure or a welded fixed structure. The first connecting portion 341 of the adapter 34 is fixedly connected to the first end 331 of the electrode terminal 33 to achieve the limiting assembly of the electrode terminal 33 on the cover plate 31 and the insulating member 32 based on the adapter 34. At this time, the electrode terminal 33 and the adapter 34 can be an integral structure to achieve a fixed connection; or the first connecting portion 341 can be attached to the end face of the first end 331, and a through weld can be performed on the surface of the first connecting portion 341 away from the insulating member to achieve a fixed connection between the first connecting portion 341 and the electrode terminal 33; or the first connecting portion 341 can have a notch, and the first end 331 of the electrode terminal 33 can be slot welded to the edge of the notch to achieve a fixed connection between the first connecting portion 341 and the electrode terminal 33.

[0062] Alternatively, the sidewall of the first end 331 of the electrode terminal 33 has a radially arranged flange, which limits the insulating member 32 on the side away from the cover plate 31, thereby achieving the limiting assembly of the electrode terminal 33 on the cover plate 31 and the insulating member 32. At the same time, the end face of the first end 331 of the electrode terminal 33 is fixedly connected to the first connecting portion 341 of the adapter 34. In this case, the fixed connection between the end face of the first end 331 and the first connecting portion 341 on the adapter 34 can refer to the fixed connection between the first end 331 and the adapter 34 described above.

[0063] The second connecting portion 342 of the adapter 34 is used for electrical connection with the electrode assembly 20, and in conjunction with the above description, it can be as follows: Figure 5 and Figure 6 As shown, the electrode assembly 20 has a tab 22 facing the end cap assembly 30, and the tab 22 is welded and fixed to the second connecting portion 342. In addition, the insulating member 32 has a venting area 321, and the venting area 321 has a venting hole 322 communicating with the explosion-proof hole 311. In this way, the venting hole 322 of the venting area 321 on the insulating member 32 can realize the communication between the receiving cavity 11 of the housing 10 and the explosion-proof hole 311, thereby ensuring the exhaust of gas in the receiving cavity 11.

[0064] For example, two electrode terminals 33 are provided on the cover plate 31 and the insulating member 32, distributed along the length direction X of the cover plate 31. The explosion-proof valve 35 is located between the two electrode terminals 33. The electrode assembly 20 has two tabs 22 facing the end cover assembly 30. At this time, both electrode terminals 33 are electrically connected to the two tabs 22 (first tab and second tab) of the electrode assembly 20 respectively through adapters 34. For example, the first electrode terminal 33 is electrically connected to the first tab through the first adapter 34, and the second electrode terminal 33 is electrically connected to the second tab through the second adapter 34. In this way, a venting gap communicating with the explosion-proof hole 311 can be formed in the area between the two adapters 34. At the same time, based on the fact that the two adapters 34 form venting channels on both sides of the venting gap along the length direction X of the cover plate 31, the gas exhaust efficiency in the receiving cavity 11 is guaranteed.

[0065] In some implementations, such as Figure 6 As shown, in the length direction X of the cover plate 31, the size d11 of the tab 22 is greater than the size d12 of the second connecting part 342.

[0066] This ensures that the electrode 22 covers the second connection portion 342, thereby ensuring the electrical connection area between the electrode 22 and the second connection portion 342, and thus ensuring the reliability of the electrical connection between the electrode 22 and the second connection portion 342, while also ensuring the overcurrent capacity between the electrode assembly 20 and the adapter 34.

[0067] Furthermore, the orthographic projection of the second connecting part 342 on the cover plate 31 may be located within the orthographic projection of the tab 22 on the cover plate 31.

[0068] This allows the tab 22 to fully cover the second connecting portion 342, thereby further ensuring the electrical connection area between the tab 22 and the second connecting portion 342. At the same time, after the insulating part 32 melts, the entire area of ​​the second connecting portion 342 can support the electrode assembly 20, thereby ensuring the support effect on the electrode assembly 20.

[0069] In some embodiments, in conjunction with the above description, the insulating member 32 has a venting area 321, and the electrode tabs 22 of the electrode assembly 20 and the venting area 321 are spaced apart in the length direction X of the cover plate 31.

[0070] Thus, a gap exists between the tab 22 of the electrode assembly 20 and the vent 321 on the insulating component 32, so as to prevent the corner of the tab 22 from extending into the vent 322 and causing the tab 22 to be electrically connected to the cover plate 31 through the explosion-proof valve 35, thereby ensuring the reliability of the insulation of the cover plate 31.

[0071] In some implementations, such as Figure 4 As shown, the adapter 34 has a flat plate structure, and the thickness of the first connecting part 341 is less than the thickness of the second connecting part 342.

[0072] Thus, after the insulating component 32 melts, the electrode assembly 20 can be reliably supported by the thickened second connecting portion 342, while an air passage is formed between the first connecting portion 341 and the electrode assembly 20. In addition, the thickened second connecting portion 342 allows for greater welding power when welding the electrode assembly 20 and the second connecting portion 342, ensuring the welding effect between the electrode assembly 20 and the second connecting portion 342 and improving the welding yield. It can also provide a larger current flow cross-section, reducing the temperature rise of the second connecting portion 342 during charging and discharging.

[0073] The orthographic projection of the adapter 34 onto the cover plate 31 (i.e., the projection along the thickness direction S of the cover plate 31) can be rectangular or the like. The adapter 34 has a flat plate structure, with the surface of the adapter 34 facing the cover plate 31 being a completely flat surface; that is, the surface of the first connecting portion 341 facing the cover plate 31 and the surface of the second connecting portion 342 facing the cover plate 31 are coplanar. In this case, a groove can be provided on the surface of the adapter 34 facing away from the cover plate 31, so that the first connecting portion 341 is formed based on the area at the bottom of the groove on the adapter 34, and the second connecting portion 342 is formed based on the area outside the groove on the adapter 34, ensuring that the thickness of the first connecting portion 341 is less than the thickness of the second connecting portion 342.

[0074] In addition to the structure described above, the adapter 34 can also be other structures, such as a Z-shaped structure in which the first connecting part 341 protrudes towards the cover plate 31. Compared to the Z-shaped structure, the flat structure of the adapter 34 simplifies the structure, improves manufacturing efficiency, and facilitates the improvement of the structural strength of the second connecting part 342, thereby ensuring the reliability of the support for the electrode assembly 20.

[0075] In some implementations, such as Figure 4 and Figure 7 As shown, the first end 331 of the electrode terminal 33 abuts against the first connecting portion 341, and the surface of the first connecting portion 341 facing away from the insulating member 32 has a protrusion 343.

[0076] Thus, through-welding can be performed on the surface of the first connecting portion 341 away from the insulating member 32 to achieve a fixed connection between the first end 331 and the first connecting portion 341; at the same time, the setting of the protrusion 343 facilitates the improvement of the surface roughness of the first connecting portion 341 away from the insulating member 32, thereby improving the reliability of through-welding between the first connecting portion 341 and the first end 331 of the electrode terminal 33; in addition, combined with the above-mentioned flat adapter 34, the support area of ​​the electrode assembly 20 can be increased based on the setting of the protrusion 343, while ensuring the formation of the air passage.

[0077] The protrusions 343 on the surface of the first connecting portion 341 facing away from the insulating member 32 can be multiple protrusions distributed in an array, or multiple protrusions extending along the length direction X of the cover plate 31 and spaced apart along the width direction Y of the cover plate 31. This application does not limit this.

[0078] In some embodiments, the second connecting portion 342 is larger than the first connecting portion 341 in the longitudinal direction X of the cover plate 31.

[0079] In this way, the support area of ​​the electrode assembly 20 can be increased by the large-sized second connecting part 342, thereby ensuring the support effect of the electrode assembly 20 and ensuring the air venting gap formed between the electrode assembly 20 and the cover plate 31 after the insulating part 32 melts; in addition, the large-sized second connecting part 342 makes it easier to increase the electrical connection area between the second connecting part 342 and the tab 22, so as to reduce the temperature rise of the second connecting part 342 during charging and discharging.

[0080] The second connecting part 342 may extend from one side of the first connecting part 341 in the length direction X of the cover plate 31, or it may extend from both sides of the first connecting part 341 in the length direction X of the cover plate 31. Accordingly, the orthographic projection of the adapter 34 on the cover plate 31 (i.e., the projection along the thickness direction S of the cover plate 31) may be L-shaped or inverted T-shaped, etc.

[0081] In some embodiments, in conjunction with the above description, the insulating member 32 has a venting area 321, and the second connecting portion 342 is spaced apart from the venting area 321 in the length direction of the cover plate 31.

[0082] Thus, based on the gap between the second connecting part 342 and the venting area 321 on the insulating member 32, while increasing the connection area between the second connecting part and the tab 22, the second connecting part 342 avoids blocking the venting hole 322 in the venting area 321, ensuring the communication area between the receiving cavity 11 of the housing 10 and the venting hole 322, thereby ensuring the gas discharge efficiency in the receiving cavity 11.

[0083] In some implementations, such as Figure 4 or Figure 7 As shown, the adapter 34 has two second connecting portions 342, which are located on both sides of the first connecting portion 341 in the width direction Y of the cover plate 31.

[0084] In this way, electrical connection with the two winding cores 21 can be achieved based on the two second connecting parts 342 of the adapter 34, thereby increasing the electrical capacity of the energy storage device 100 and ensuring the power supply duration of the energy storage device 100 by setting the two winding cores 21.

[0085] The orthographic projection of the adapter 34 on the cover plate 31 (i.e., the projection along the thickness direction S of the cover plate 31) can be rectangular. Of course, in conjunction with the above, the size of the second connecting part 342 is larger than the size of the first connecting part 341 in the length direction X of the cover plate 31. In this case, the orthographic projection of the adapter 34 on the cover plate 31 (i.e., the projection along the thickness direction S of the cover plate 31) can be H-shaped or the like.

[0086] In some implementations, such as Figure 4 or Figure 7 As shown, the end cap assembly 30 also includes a heat insulation sheet 36, which is located between the second connection portion 342 and the insulating member 32.

[0087] Thus, by setting the heat insulation sheet 36, the welding heat can be avoided from being conducted to the insulating part 32 during the welding of the second connecting part 342 and the electrode 22, which would cause the insulating part 32 to soften locally or even melt through. This ensures the manufacturing yield of the insulating part 32 and thus ensures the reliability of the electrical isolation of the cover plate 31.

[0088] The heat insulation pad can be made of insulating material or high-temperature resistant material. In this case, the heat insulation pad can support the second connecting portion 342, increasing the distance between the surface of the second connecting portion 342 facing away from the cover plate 31 and the cover plate 31. This effectively ensures the air venting gap between the electrode assembly 20 and the cover plate 31 after the insulating component 32 melts. Furthermore, the heat insulation sheet 36 can be fixed to the insulating component 32 or to the surface of the second connecting portion 342 facing the insulating component 32. When the heat insulation sheet 36 is fixed to the surface of the second connecting portion 342 facing the insulating component 32, it facilitates the positioning of the heat insulation sheet 36 and the electrode terminal 33 in the width direction Y of the cover plate 31, improving the assembly efficiency of the adapter 34.

[0089] In some implementations, such as Figure 4 and Figure 7 As shown, the first connecting portion 341 has a through hole 345, and the first end portion 331 extends into the through hole 345 and is fixedly connected to the edge of the opening of the through hole 345. At this time, a protective film 344 is provided on the surface of the first connecting portion 341 facing away from the insulating member 32, and the protective film 344 covers the edge of the opening of the through hole 345.

[0090] Thus, by setting the protective film 344, the weld marks of the first connecting part 341 and the first end 331 are covered to prevent the weld slag on the first connecting part 341 from falling off and piercing the diaphragm included in the electrode assembly 20.

[0091] The protective film 344 applied to the surface of the first connecting part 341 can be an insulating film or a conductive film.

[0092] In some embodiments, the insulating member 32 has a positioning protrusion 323 facing away from the cover plate 31; the adapter 34 has a positioning protrusion 323 on at least one side of the cover plate 31 in the length direction X and / or width direction Y, and the edge of the adapter 34 abuts against the positioning protrusion 323.

[0093] Thus, the positioning protrusion 323 on the insulating member 32 facing away from the cover plate 31 facilitates the positioning and assembly of the adapter 34, thereby improving the assembly efficiency of the end cap assembly 30. For example, as... Figure 6 or Figure 7 As shown, the adapter 34 has a positioning protrusion 323 on one side of the cover plate 31 in the length direction X.

[0094] The positioning protrusion 323 can be an integral structure on the insulating component 32, or a structure assembled and fixed on the insulating component 32, etc.

[0095] This application also provides a power supply system 500, such as... Figure 8 As shown, the power supply system 500 includes: electrical equipment 510 and the energy storage device 100 described in the above embodiments, the energy storage device 100 being used to supply power to the electrical equipment 510.

[0096] The electrical device 510 is electrically connected to the energy storage device 100. Thus, in conjunction with the above description, the power supply system of this application ensures the safety of the electrical device 510 during use by considering the safety of the energy storage device 100 in the event of thermal runaway.

[0097] In the embodiments of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium; "fix" can be a non-detachable fixation or a detachable fixation (such as non-destructive or destructive disassembly). Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0098] In the description of the embodiments of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0099] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the implementation of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0100] The above are merely preferred embodiments of the implementation methods of this application and are not intended to limit the implementation methods of this application. For those skilled in the art, various modifications and variations can be made to the implementation methods of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the implementation methods of this application should be included within the protection scope of the implementation methods of this application.

Claims

1. An end cap assembly (30), characterized in that, include: Cover plate (31), the cover plate (31) is rectangular and has an explosion-proof hole (311), and an explosion-proof valve (35) is provided in the explosion-proof hole (311). An insulating element (32) is located on the first side of the cover plate (31) in the thickness direction (S); Electrode terminals (33) are disposed on the cover plate (31) and the insulating member (32), and have a first end (331) and a second end (332). The first end (331) is located on a first side of the cover plate (31), and the second end (332) is exposed on a second side of the cover plate (31) in the thickness direction (S). The adapter (34) is located on the side of the insulating member (32) away from the cover plate (31) and has a first connecting portion (341) and a second connecting portion (342) distributed along the width direction (Y) of the cover plate (31). The first connecting portion (341) is fixedly connected to the first end (331), and the second connecting portion (342) is used for electrical connection with the electrode assembly (20). The distance between the surface of the first connecting portion (341) away from the insulating member (32) and the cover plate (31) is smaller than the distance between the surface of the second connecting portion (342) away from the insulating member (32) and the cover plate (31).

2. The end cap assembly (30) as claimed in claim 1, characterized in that, The adapter (34) has a flat plate structure, and the thickness of the first connecting part (341) is less than the thickness of the second connecting part (342).

3. The end cap assembly (30) as claimed in claim 1, characterized in that, In the length direction (X) of the cover plate (31), the size of the second connecting part (342) is larger than the size of the first connecting part (341).

4. The end cap assembly as claimed in claim 3, characterized in that, The insulating component (32) has a venting area (321), the venting area (321) has a venting hole (322) that communicates with the explosion-proof hole (311), and the second connecting part (342) and the venting area (321) are spaced apart in the length direction of the cover plate (31).

5. The end cap assembly (30) as claimed in claim 1, characterized in that, The adapter (34) has two second connecting parts (342), which are located on both sides of the first connecting part (341) in the width direction (Y) of the cover plate (31).

6. The end cap assembly (30) as described in any one of claims 1-5, characterized in that, The end cap assembly (30) also includes a heat insulation sheet (36) located between the second connection portion (342) and the insulating member (32).

7. The end cap assembly (30) as described in any one of claims 1-5, characterized in that, The first connecting part (341) has a through hole (345), the first end part (331) extends into the through hole (345) and is fixedly connected to the edge of the opening of the through hole (345); The first connecting part (341) has a protective film (344) on its surface facing away from the insulating member (32), and the protective film (344) covers the edge of the opening of the through hole (345).

8. The end cap assembly as described in any one of claims 1-5, characterized in that, The insulating element (32) has a positioning protrusion (323) facing away from the cover plate (31). The adapter (34) has the positioning protrusion (323) on at least one side of the cover plate (31) in the length direction (X) and / or width direction (Y), and the edge of the adapter (34) abuts against the positioning protrusion (323).

9. An energy storage device, characterized in that, include: The housing (10) includes a receiving cavity (11) with an opening. The electrode assembly (20) is housed within the receiving cavity (11); The end cap assembly (30) according to any one of claims 1-8, the end cap assembly (30) sealing the opening of the receiving cavity (11).

10. The energy storage device as described in claim 9, characterized in that, The electrode assembly (20) has tabs (22) facing the end cap assembly (30); The tab (22) is electrically connected to the second connecting part (342), and in the length direction (X) of the cover plate (31), the size of the tab (22) is larger than the size of the second connecting part (342).

11. The energy storage device as described in claim 10, characterized in that, The orthographic projection of the second connecting part (342) on the cover plate (31) is located within the orthographic projection of the tab (22) on the cover plate (31).

12. The energy storage device as described in claim 10, characterized in that, The insulating element (32) has a venting area (321), and the tab (22) and the venting area (321) are spaced apart along the length of the cover plate.

13. A power supply system, characterized in that, The power supply system (500) includes electrical equipment (510) and an energy storage device (100) according to any one of claims 9-12, wherein the energy storage device (100) supplies power to the electrical equipment (510).

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