End cover assembly, energy storage device and household energy storage system

Abstract

The present application provides an end cover assembly, an energy storage device and a household energy storage system, including an end cover, a lower plastic, a current collector and a terminal post. The lower plastic includes a plastic body, a first stop strip portion and a second stop strip portion. The plastic body includes a first surface facing away from the end cover. The first stop strip portion and the second stop strip portion are provided on the first surface. Both the first stop strip portion and the second stop strip portion include at least one stop strip. The width of the end of the stop strip connected to the plastic body is greater than the width of the end of the stop strip away from the plastic body. The current collector includes a first connection portion, a second connection portion and a bending portion. The bending portion is connected between the first connection portion and the second connection portion. The first connection portion is connected to the first surface. The first connection portion is located in the middle region. The orthographic projection of the second connection portion on the plastic body at least partially covers the first stop strip portion and the second stop strip portion. The technical solution of the present application can avoid excessive bending of the current collector, thereby avoiding the failure of the energy storage device due to the fracture of the current collector.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage, and particularly relates to an end cover assembly, an energy storage device, and a household energy storage system. Background Art

[0002] Generally, a metal part is provided in the end cover assembly of an energy storage device, and the metal part can play a role in electrically connecting the electrode assembly and the end cover assembly. During the assembly process of the energy storage device, the metal part can be first connected to the electrode assembly, and then by bending the metal part, the electrode assembly and the end cover assembly are aligned. Then, the electrode assembly is placed in the housing, so that the end cover assembly is connected to the housing to complete the assembly of the energy storage device. After the metal part is bent at a large angle, it approaches the metal fatigue limit and is extremely easy to break due to vibration during use, resulting in the failure of the energy storage device. Summary of the Invention

[0003] Embodiments of the present application provide an end cover assembly, an energy storage device, and a household energy storage system, which can avoid excessive bending of the metal part, thereby avoiding the failure of the energy storage device due to the fracture of the metal part.

[0004] In a first aspect, the present application provides an end cover assembly, including:

[0005] An end cover;

[0006] A lower plastic, the lower plastic includes a plastic body, a first stop portion, and a second stop portion. The plastic body is stacked with the end cover. The plastic body includes a first surface facing away from the end cover. The first stop portion and the second stop portion are provided on the first surface. An intermediate region is formed between the first stop portion and the second stop portion. Both the first stop portion and the second stop portion include at least one stop strip. The width of the end of the stop strip connected to the plastic body is greater than the width of the end of the stop strip away from the plastic body; and

[0007] A current collector, the current collector includes a first connection portion, a second connection portion, and a bending portion. The bending portion is connected between the first connection portion and the second connection portion. The first connection portion and the second connection portion are stacked and spaced apart. The first connection portion is connected to the first surface. The first connection portion is located in the intermediate region. The orthographic projection of the second connection portion on the plastic body at least partially covers the first stop portion and the second stop portion;

[0008] A pole column, the pole column sequentially penetrates through the first connection portion, the lower plastic, and the end cover.

[0009] It can be understood that the first stop strip portion and the second stop strip portion are disposed between the second connecting portion and the plastic body. Therefore, the first stop strip portion and the second stop strip portion can keep a certain gap between the first connecting portion and the second connecting portion all the time. The existence of the gap can prevent the second connecting portion from directly contacting the first connecting portion, so that the bending angle of the bending portion will not be too large, avoiding the bending portion reaching the metal fatigue limit. Furthermore, it ensures that the current collector is not easily broken during use and prevents the energy storage device from failing.

[0010] In a possible implementation manner, the first stop strip portion includes a first stop strip and a second stop strip. The first stop strip is located on a side of the second stop strip away from the middle region. A first flow channel is formed between the first stop strip and the second stop strip;

[0011] The second stop strip portion includes a third stop strip and a fourth stop strip. The third stop strip is located on a side of the fourth stop strip away from the middle region. A second flow channel is formed between the third stop strip and the fourth stop strip.

[0012] It can be understood that the first flow channel and the second flow channel can allow gas to pass through, so as to provide a flow path for the gas generated by the energy storage device during use, enabling the gas to flow along the path instead of directly flowing to the explosion-proof grid holes of the lower plastic. This avoids the instantaneous increase in local air pressure at the explosion-proof grid holes, which may cause the explosion-proof valve to be accidentally triggered.

[0013] In a possible implementation manner, the first stop strip includes a first end and a second end which are oppositely arranged. The second stop strip includes a third end and a fourth end which are oppositely arranged. The first end and the third end are arranged on the same side, and the second end and the fourth end are arranged on the same side. The projection of the first end on the plastic body has a first distance from the edge of the plastic body. The projection of the second end on the plastic body coincides with the edge of the plastic body. The projection of the third end on the plastic body coincides with the edge of the plastic body. The projection of the fourth end on the plastic body has a second distance from the edge of the plastic body;

[0014] The third stop strip includes a fifth end and a sixth end which are oppositely arranged. The fourth stop strip includes a seventh end and an eighth end which are oppositely arranged. The fifth end and the seventh end are arranged on the same side, and the sixth end and the eighth end are arranged on the same side. The projection of the fifth end on the plastic body has a third distance from the edge of the plastic body. The projection of the sixth end on the plastic body coincides with the edge of the plastic body. The projection of the seventh end on the plastic body coincides with the edge of the plastic body. The projection of the eighth end on the plastic body has a fourth distance from the edge of the plastic body.

[0015] It can be understood that since there is a first distance between the first end and the edge of the plastic body, there is a gap between the first end and the housing after the end cap assembly is connected to the housing. The flow channels on both sides of the first baffle can communicate through this gap. Thus, the gas can pass through the flow channels on both sides of the first baffle in sequence. Since there is a second distance between the fourth end and the edge of the plastic body, there is a gap between the fourth end and the housing after the end cap assembly is connected to the housing. This gap can allow the airflow in the first flow channel to flow towards the middle area of the plastic body and can flow to the position where the explosion-proof grid holes are located. When the internal pressure of the energy storage device is too high, the explosion-proof valve of the energy storage device will be pushed open by the internal air pressure, and the gas can pass through the explosion-proof grid holes on the plastic body to complete pressure relief. The function of the second baffle part is the same as that of the first baffle part, and will not be elaborated here.

[0016] In a possible implementation manner, the first baffle part further includes a first edge strip, the first edge strip is arranged on the first surface along the circumferential direction of the plastic body, the first edge strip is located on the side of the first baffle away from the second baffle, and a third flow channel is formed between the first edge strip and the first baffle;

[0017] The second baffle part includes a second edge strip, the second edge strip is arranged on the first surface along the circumferential direction of the plastic body, the second edge strip is located on the side of the third baffle away from the fourth baffle, and a fourth flow channel is formed between the second edge strip and the third baffle.

[0018] It can be understood that the first edge strip and the first baffle can form a third flow channel, and a fourth flow channel can be formed between the second edge strip and the third baffle. The third flow channel and the first flow channel communicate through the gap between the first end and the housing, and the fourth flow channel and the second flow channel communicate through the gap between the fourth end and the housing, so that the length of the gas flow channel is longer, and further delays the time for the gas to gather around the explosion-proof grid holes of the plastic body. Further avoid the sudden increase in local air pressure at the explosion-proof grid holes, so as to avoid the accidental triggering of the explosion-proof valve of the energy storage device.

[0019] In a possible implementation manner, in the direction away from the first surface on the first surface, the widths of the first baffle, the second baffle, the third baffle and the fourth baffle gradually become smaller; or,

[0020] In the direction away from the first surface on the first surface, the width gradients of the first baffle, the second baffle, the third baffle and the fourth baffle become smaller.

[0021] It can be understood that since the widths of the first stop bar, the second stop bar, the third stop bar, and the fourth stop bar at the ends far from the plastic body are relatively small, their plastic structures are relatively soft. Therefore, the first stop bar, the second stop bar, the third stop bar, and the fourth stop bar can play a buffering role between the plastic body and the second connecting portion of the current collector. When the end cap assembly is subjected to an external force impact, due to inertia, the second connecting portion of the current collector may move closer to the first connecting portion. Since the structures of the ends of the first stop bar, the second stop bar, the third stop bar, and the fourth stop bar far from the plastic body are relatively soft, they will play a buffering and supporting role for the second connecting portion and will not cause damage to the second connecting portion.

[0022] In a possible implementation manner, the width range of the end of the first stop bar connected to the first surface is between 1.5 mm and 3.5 mm.

[0023] It can be understood that when the width of the end of the first stop bar close to the first surface is too small, the connection strength between the first stop bar and the plastic body is too low, which will cause the first stop bar to easily collapse under an external force. When the width of the end of the first stop bar close to the first surface is too large, the first stop bar will occupy too much space in the first channel, so that the gas cannot pass smoothly through the first flow channel, resulting in too high local air pressure in the first flow channel, and there may be a risk of explosion of the energy storage device.

[0024] In a possible implementation manner, the width range of the end of the first stop bar far from the first surface is between 0.8 mm and 1.2 mm.

[0025] It can be understood that when the width of the end of the first stop bar far from the plastic body is too small, the hardness of this end of the first stop bar is too low to effectively support the current collector. When the width of the end of the first stop bar far from the plastic body is too large, the hardness of this end of the first stop bar is too high to undergo elastic deformation. Therefore, when the current collector is impacted, the first stop bar cannot buffer the second connecting portion of the current collector through elastic deformation.

[0026] In a possible implementation manner, it further includes a first enclosure and a second enclosure. The first enclosure and the second enclosure are connected to the first surface. One end of the first enclosure is connected to one end of the first edge bar, and the other end of the first enclosure is connected to the second end of the first stop bar. One end of the second enclosure is connected to the other end of the first edge bar, and the other end of the second enclosure is connected to the third end of the second stop bar. There is a gap between the second enclosure and the first end, and the third flow channel and the first flow channel communicate through the gap between the second enclosure and the first end.

[0027] It can be understood that the first baffle can block one end of the third flow channel, enabling the air flow to flow out from the other end of the third flow channel. The second baffle can help deflect the air flow in the third flow channel, and the air flow can flow from the third flow channel to the first flow channel along the curvature of the second baffle.

[0028] In a possible implementation, it further includes an explosion-proof grid hole, a pole column through hole, and a third baffle portion. The explosion-proof grid hole penetrates through the plastic body along the thickness direction of the plastic body. Both the explosion-proof grid hole and the pole column through hole are located in the middle region, and the explosion-proof grid hole and the pole column through hole are spaced apart.

[0029] The third baffle portion is connected to the first surface, is located in the middle region, and is disposed between the explosion-proof grid hole and the pole column through hole.

[0030] It can be understood that when the air pressure inside the energy storage device is too high, causing the tab or insulating film of the electrode assembly to break, the third baffle portion arranged around the anti-through hole can block the broken tab or insulating film, allowing only the air flow to pass through. Thus, it can prevent the broken tab or insulating film from blocking the explosion-proof grid hole, resulting in the failure of the explosion-proof valve.

[0031] In a possible implementation, the extending direction of the third baffle portion intersects with the extending direction of the first baffle portion, and the extending direction of the third baffle portion also intersects with the extending direction of the second baffle portion.

[0032] In a possible implementation, the third baffle portion includes a fifth baffle, a sixth baffle, and a seventh baffle. The fifth baffle is located between the explosion-proof grid hole and the first baffle portion. The sixth baffle is located between the explosion-proof grid hole and the second baffle portion. The seventh baffle is located on the side of the explosion-proof grid hole facing the center of the plastic body. A fluid channel is formed between the fifth baffle and the seventh baffle, and another fluid channel is formed between the sixth baffle and the seventh baffle.

[0033] It can be understood that by arranging the fifth baffle on one side of the explosion-proof grid hole and forming a fifth flow channel in cooperation with the seventh baffle, the fifth flow channel can allow the gas on the side of the explosion-proof grid hole facing the first baffle portion to pass through. By arranging the sixth baffle on the other side of the explosion-proof grid hole and forming a sixth flow channel in cooperation with the seventh baffle, the sixth flow channel can allow the gas on the side of the explosion-proof grid hole facing the second baffle portion to pass through. That is to say, by sequentially arranging the fifth baffle, the seventh baffle, and the sixth baffle around the explosion-proof grid hole, the fifth baffle, the seventh baffle, and the sixth baffle can cooperate to surround the explosion-proof grid hole, playing a role in integrating the air flow around the explosion-proof grid hole. In addition, since the fifth flow channel and the sixth flow channel are relatively long and narrow, broken tab or insulating sheet splashing can be blocked by the fifth baffle, the sixth baffle, and the seventh baffle in the aforementioned flow channels, avoiding broken tab or insulating sheet on the side of the explosion-proof grid hole facing the second pole column through hole from passing through, which is beneficial to preventing the explosion-proof grid hole from being blocked by foreign objects and causing the explosion-proof valve to fail.

[0034] In a possible implementation manner, the extending direction of the first baffle portion is linear extension or curved extension, the extending direction of the second baffle portion is linear extension or curved extension, and the extending direction of the third baffle portion is linear extension or curved extension.

[0035] It can be understood that when the first baffle portion and the second baffle portion extend linearly on the first surface, the first flow channel of the first baffle portion and the second flow channel of the second baffle portion can be linear flow channels. The linear flow channels can form a long and narrow air passage, so that the gas generated when the energy storage device is in use can flow along the flow channels to the explosion-proof grid hole, avoiding the gas from directly instantaneously gathering and then passing through the explosion-proof grid hole to impact the explosion-proof valve, resulting in false triggering of the explosion-proof valve.

[0036] In addition, when the first baffle portion and the second baffle portion extend curvilinearly on the first surface, the first flow channel and the second flow channel can be arranged in a serpentine shape, and the length of the curved flow channels is greater than the length of the linear flow channels. Therefore, the curved first flow channel and the second flow channel can make the flow path of the air flow generated during the use of the energy storage device longer, so that the process of gas gathering at the explosion-proof grid hole is slower. Extending the gas gathering time can better avoid the gas from instantaneously converging and falsely triggering the explosion-proof valve.

[0037] In a possible implementation manner, the height range of the third baffle portion is between 1.2 mm and 2.5 mm.

[0038] It can be understood that the third baffle portion is arranged between the first connecting portion of the current collector and the plastic body. When the height of the third baffle portion is too low, it cannot play a role in intercepting debris. When the height of the third baffle portion is too high, the distance between the first connecting portion and the plastic body will be too large, affecting the connection stability between the first connecting portion and the plastic body.

[0039] In a possible implementation, the height range of the first retaining strip portion and the second retaining strip portion is between 3.5 mm and 5.5 mm.

[0040] It can be understood that the first retaining strip portion and the second retaining strip portion are located between components such as the plastic body and the electrode assembly. Since the space between the plastic body and the electrode assembly is limited, the height of the first retaining strip portion and the second retaining strip portion does not exceed 6.5 mm. And when the first retaining strip portion and the second retaining strip portion are less than 3.5 mm, the formed gas flow channel is too shallow to play a role in guiding the gas. Therefore, the height range of the first retaining strip portion and the second retaining strip portion provided in this application is between 3.5 mm and 6.5 mm.

[0041] In a possible implementation, the lower plastic further includes a limiting rib, the limiting rib is connected to the first surface of the plastic body, and the limiting rib is located in the middle region, and one side of the limiting rib abuts against the first connecting portion of the current collector.

[0042] It can be understood that the limiting rib can limit the current collector. Thus, when the end cap assembly is subjected to an external force impact or vibrates during use, the relative displacement between the current collector and the lower plastic is reduced, thereby preventing the current collector from falling off the lower plastic due to insufficient connection strength with the lower plastic.

[0043] In a second aspect, this application provides an energy storage device, including an electrode assembly and the end cap assembly as described above, and the second connecting portion of the current collector is electrically connected to the electrode assembly.

[0044] In a third aspect, a household energy storage device of this application includes a load and the energy storage device as described above, and the energy storage device is used to supply power to the load. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of this application, the drawings required for implementation will be briefly introduced below. Obviously, the drawings in the following description are only some implementations of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained from these drawings.

[0046] Figure 1 is a household energy storage system provided by an embodiment of this application;

[0047] Figure 2 is Figure 1 a schematic structural diagram of the energy storage device shown;

[0048] Figure 3 is Figure 2 a schematic structural diagram of an end cap assembly of the energy storage device shown, where the current collector is not bent;

[0049] Figure 4 is Figure 3 a schematic exploded view of the end cap assembly shown, wherein the current collector is not bent;

[0050] Figure 5 is Figure 4 a schematic structural view of the end cap shown;

[0051] Figure 6 is Figure 3 a schematic structural view of the lower plastic in the first embodiment shown;

[0052] Figure 7 is Figure 3 a schematic structural view of the current collector after being bent shown;

[0053] Figure 8 is Figure 3 a schematic structural view of an end cap assembly shown, wherein the current collector is not bent;

[0054] Figure 9 is Figure 3 a schematic partial structural view of another end cap assembly shown;

[0055] Figure 10 is Figure 3 a schematic structural view of another lower plastic in the first embodiment shown;

[0056] Figure 11 is Figure 10 a schematic sectional view of the lower plastic shown;

[0057] Figure 12 is Figure 3 a schematic structural view of the lower plastic in the second embodiment shown;

[0058] Figure 13 is Figure 3 a schematic structural view of the lower plastic in the third embodiment shown.

[0059] Reference numerals: residential energy storage system 1001, power conversion device 300, load 400, energy storage device 1000, housing 100, end cover assembly 200, end cover 210, explosion-proof valve 220, lower plastic 230, current collector 240, terminal post 250, upper plastic 260, voltage-conducting block 270, explosion-proof valve through-hole 211, first terminal post through-hole 212, plastic body 231, first bar portion 232, second bar portion 233, first surface 2311, second surface 2312, first edge region 2313, second edge region 2314, middle region 2315, explosion-proof grid hole 2316, second terminal post through-hole 2317, limiting rib 2318, first connection portion 241, second connection portion 242, bending portion 243, first bar 2321, second bar 2322, first edge strip 2323, first flow channel 2324, third flow channel 2325, first end 2326, second end 2327, third end 2328, fourth end 2329, first distance D1, second distance D2, third bar 2331, fourth bar 2332, second edge strip 2333, second flow channel 2334, fourth flow channel 2335, fifth end 2336, sixth end 2337, seventh end 2338, eighth end 2339, third distance D3, fourth distance D4, arc-shaped enclosure 234, first enclosure 2341, second enclosure 2342, third enclosure 2343, fourth enclosure 2344, third bar portion 235, fifth bar 2351, sixth bar 2352, seventh bar 2353, eighth bar 2354, width D5 of the end of the first bar 2321 connected to the first surface 2311, width D6 of the end of the first bar 2321 away from the first surface 2311, height D7 of the second bar portion 233, height D8 of the third bar portion 235, fifth flow channel 2355, sixth flow channel 2356. Detailed implementation manners

[0060] For the convenience of understanding, first, the terms involved in the embodiments of the present application are explained.

[0061] And / or: It is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone.

[0062] Multiple: It means two or more than two.

[0063] Connection: It should be understood in a broad sense. For example, the connection between A and B may be that A is directly connected to B, or A is indirectly connected to B through an intermediate medium.

[0064] Next, the specific implementation manners of the present application will be clearly described in conjunction with the accompanying drawings.

[0065] Since the energy required by people has strong temporality and spatiality, in order to rationally utilize energy and improve the energy utilization rate, it is necessary to store one form of energy in the same or converted into another form of energy through a medium or device, and then release it in a specific energy form based on future application needs. As is well known, to achieve the major goal of carbon neutrality, the current main way to generate green electricity is to develop green energy such as photovoltaic and wind power to replace fossil energy.

[0066] Currently, the generation of green electricity generally depends on photovoltaic, wind power, water potential, etc. However, wind energy and solar energy generally have problems such as strong intermittency and large volatility, which will cause the power grid to be unstable, there is not enough electricity during peak electricity consumption, and too much electricity during low electricity consumption. The unstable voltage will also damage the power, so the problems of "abandoning wind and light" may be caused due to insufficient electricity demand or insufficient grid acceptance capacity. To solve these problems, energy storage is required. That is, the electric energy is converted into other forms of energy and stored through physical or chemical means, and the energy is converted into electric energy and released when needed. Simply put, energy storage is similar to a large "power bank". When photovoltaic and wind energy are sufficient, the electric energy is stored, and the stored electric energy is released when needed.

[0067] Taking electrochemical energy storage as an example, this solution provides an energy storage device. The energy storage device includes a chemical battery, which mainly uses the chemical elements in the chemical battery as the energy storage medium. The charge and discharge process is accompanied by chemical reactions or changes of the energy storage medium. Simply put, the electric energy generated by wind energy and solar energy is stored in the chemical battery, and the stored electricity is released when the external electricity usage reaches the peak, or transferred to places with a shortage of electricity for further use.

[0068] Currently, the application scenarios of energy storage (i.e., energy storage) are relatively extensive, including power generation side energy storage, grid side energy storage, renewable energy grid connection energy storage, and user side energy storage, etc. The types of corresponding energy storage devices include:

[0069] (1) The large energy storage container applied in the grid side energy storage scenario can be used as a high-quality active and reactive power regulation power source in the grid, realizing the load matching of electric energy in time and space, enhancing the consumption capacity of renewable energy, and being of great significance in grid system standby, relieving the power supply pressure during peak loads, and peak shaving and frequency modulation.

[0070] (2) Small and medium-sized energy storage cabinets applied to industrial and commercial energy storage scenarios (banks, shopping malls, etc.) on the user side and household small energy storage boxes applied to household energy storage scenarios on the user side mainly operate in the mode of "peak shaving and valley filling". Due to the large price difference in electricity charges at peak and valley positions according to electricity consumption demand, after users have energy storage devices, in order to reduce costs, they usually charge the energy storage cabinet / box during the low electricity price period and release the electricity in the energy storage device for use during the high electricity price period to achieve the purpose of saving electricity charges. In addition, in remote areas and areas with high incidence of natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices is equivalent to users providing backup power for themselves and the power grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0071] The embodiments of this application will be described by taking the household energy storage scenario in user-side energy storage as an example. Please refer to Figure 1 , Figure 1 which is the household energy storage system 1001 provided by the embodiments of this application.

[0072] The household energy storage system 1001 includes an electric energy conversion device 300 (solar panel), a user load 400 (household appliances), etc. and an energy storage device 1000. The energy storage device 1000 can be a battery or an energy storage box and can be installed on an outdoor wall in a wall-mounted manner. Specifically, the solar panel can convert solar energy into electric energy during the low electricity price period, and the energy storage device 1000 is used to store the electric energy and supply it to street lights and household appliances for use during the high electricity price period, or supply power when the power grid is powered off / out of power. It should be noted that the energy storage device 1000 of this application is not limited to the household energy storage scenario.

[0073] Please refer to Figure 2 , Figure 2 which is Figure 1 the structural schematic diagram of the energy storage device 1000 shown. Among them, the Z direction is the height direction of the energy storage device 1000.

[0074] In the embodiments of this application, the energy storage device 1000 takes a cylindrical lithium-ion battery as an example. The energy storage device 1000 includes a housing 100, an electrode assembly (not shown in the figure), and an end cap assembly 200. The housing 100 can be a cylindrical housing, and one end of the housing 100 is provided with an opening. The electrode assembly is installed inside the housing 100. Along the Z-axis direction, the end cap assembly 200 is connected to the opening of the housing 100 and is electrically connected to the electrode assembly.

[0075] The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate and the negative electrode plate are spaced apart and oppositely arranged, and the separator is located between the positive electrode plate and the negative electrode plate. Exemplarily, after the positive electrode plate, the separator, and the negative electrode plate are stacked in sequence, they are wound to form an electrode assembly. Among them, the tab of the negative electrode plate is the negative electrode tab. The negative electrode plate is electrically connected to the end cap assembly 200 through the negative electrode tab.

[0076] In the end cap assembly of an energy storage device, a metal part is generally provided, which can play the role of electrically connecting the electrode assembly and the end cap assembly. During the assembly process of the energy storage device, the metal part can be first connected to the electrode assembly, and then by bending the metal part, the electrode assembly and the end cap assembly are aligned. Then, the electrode assembly is placed in the housing, so that the end cap assembly is connected to the housing to complete the assembly of the energy storage device. However, after the metal part is bent at a large angle, it is close to the metal fatigue limit and is extremely likely to vibrate and break during use, resulting in the failure of the energy storage device.

[0077] Based on this, the present application provides an end cap assembly 200, which can avoid excessive bending of the current collector (not shown in the figure), thereby avoiding the failure of the energy storage device 1000 due to the fracture of the current collector.

[0078] Refer to Figure 3 and Figure 4 , Figure 3 is Figure 2 a schematic structural diagram of the end cap assembly 200 of the energy storage device 1000 shown in the figure, where the current collector 240 is not bent. Figure 4 is Figure 3 a schematic exploded structural diagram of the end cap assembly 200 shown in the figure. Among them, the current collector 240 is not bent.

[0079] The end cap assembly 200 includes an end cap 210, an explosion-proof valve 220, a lower plastic 230, a current collector 240, a terminal post 250, an upper plastic 260, and a voltage-conducting block 270. In the embodiment provided by the present application, the end cap assembly 200 is a negative end cap assembly, the end cap 210 in the end cap assembly 200 is a negative end cap, the terminal post 250 in the end cap assembly 200 is a negative terminal post, and the current collector 240 in the end cap assembly 200 is a negative current collector.

[0080] It should be noted that Figure 3 the purpose of Figure 3 is only to schematically describe the connection relationship of the end cap 210, the explosion-proof valve 220, the lower plastic 230, the current collector 240, the terminal post 250, the upper plastic 260, and the voltage-conducting block 270, and does not specifically limit the connection positions, specific structures, and quantities of each device. The structure schematically shown in the embodiment of the present application does not constitute a specific limitation on the end cap assembly 200. In other embodiments of the present application, the end cap assembly 200 includes more or fewer components than Figure 3 shown in the figure, or combines certain components, or splits certain components, or has different component arrangements. Figure 3 The components shown in the figure can be implemented in hardware, software, or a combination of software and hardware.

[0081] Please refer to Figure 5 , Figure 5 is Figure 4Schematic structural diagram of the end cap 210 shown. The end cap 210 can be made of a conductive material. The end cap 210 includes an explosion-proof valve through hole 211 and a first pole column through hole 212. The first pole column through hole 212 can be located at the middle position of the end cap 210. The explosion-proof valve through hole 211 and the first pole column through hole 212 are arranged at intervals.

[0082] The explosion-proof valve 220 seals the explosion-proof valve through hole 211. The explosion-proof valve 220 can be partially or completely separated from the end cap 210 when the pressure inside the housing 100 is too high. Thereby forming a gas channel, so that the air pressure inside the housing 100 can be quickly reduced, and further avoiding the explosion of the energy storage device 1000.

[0083] Please refer to Figure 6 , Figure 6 is Figure 3 Schematic structural diagram of the lower plastic 230 in the first embodiment shown. The lower plastic 230 includes a plastic body 231, a first bar portion 232 and a second bar portion 233. The plastic body 231 and the end cap 210 are stacked. The shape of the plastic body 231 can be circular. The plastic body 231 includes a first surface 2311 and a second surface 2312 that are oppositely arranged in the thickness direction. The first surface 2311 includes a first edge region 2313, a second edge region 2314 and a middle region 2315. The first edge region 2313 and the second edge region 2314 are respectively located on opposite sides of the middle region 2315.

[0084] The first bar portion 232 and the second bar portion 233 are arranged on the first surface 2311. The first bar portion 232 is located in the first edge region 2313, and the second bar portion 233 is located in the second edge region 2314. An intermediate region 2315 is formed between the first bar portion 232 and the second bar portion 233. Exemplarily, the height of the first bar portion 232 and the height of the second bar portion 233 are D7, and 3.5mm ≤ D7 ≤ 6.5mm. The height D7 of the first bar portion 232 and the second bar portion 233 is the distance they extend from the first surface 2311 in a direction away from the first surface 2311.

[0085] It can be understood that the first bar portion 232 and the second bar portion 233 are located between components such as the plastic body 231 and the electrode assembly. Since the space between the plastic body 231 and the electrode assembly is limited, the height of the first bar portion 232 and the second bar portion 233 does not exceed 6.5mm. And when the first bar portion 232 and the second bar portion 233 are less than 3.5mm, the formed gas flow channel is too shallow to play a role in guiding the gas. Therefore, the height range of the first bar portion 232 and the second bar portion 233 provided in this application is between 3.5mm - 6.5mm.

[0086] The plastic body 231 is also provided with explosion-proof grid holes 2316 and pole post through holes. Among them, the pole post through hole is also the second pole post through hole 2317 described below. Both the explosion-proof grid holes 2316 and the second pole post through hole 2317 penetrate through the first surface 2311 and the second surface 2312, and are both located in the middle area 2315. The second pole post through hole 2317 is located at the center of the plastic body 231. The explosion-proof grid holes 2316 and the second pole post through hole 2317 are arranged at intervals. Exemplarily, the explosion-proof grid holes 2316 and the second pole post through hole 2317 can be arranged at intervals in the extending direction of the first retaining strip portion 232 and the second retaining strip portion 233. The position of the explosion-proof grid holes 2316 of the plastic body 231 is correspondingly arranged with the position of the explosion-proof valve through hole 211 of the end cover 210, and the position of the second pole post through hole 2317 of the plastic body 231 is correspondingly arranged with the position of the first pole post through hole 212 of the end cover 210.

[0087] The lower plastic 230 further includes a limiting rib 2318. The limiting rib 2318 is connected to the first surface 2311 of the plastic body 231, and the limiting rib 2318 is located in the middle area 2315. The limiting rib 2318 is used for abutting against the current collector 240.

[0088] It can be understood that the limiting rib 2318 can limit the current collector 240. Thus, when the energy storage device 1000 is subjected to an external impact or vibrates during use, the relative displacement between the current collector 240 and the lower plastic 230 is reduced, thereby preventing the current collector 240 from falling off the lower plastic 230 due to insufficient connection strength with the lower plastic 230.

[0089] Please refer to Figure 7 and Figure 8 , Figure 7 is Figure 3 the schematic structural diagram of the bent current collector 240 shown in Figure 8 is Figure 3 the schematic structural diagram of a kind of end cover assembly 200 shown in Figure 8 , where the current collector 240 is not bent. The current collector 240 includes a first connecting portion 241, a second connecting portion 242, and a bending portion 243. The bending portion 243 is connected between the first connecting portion 241 and the second connecting portion 242. In Figure 7In the bent state of the current collector member 240 shown, the first connection portion 241 and the second connection portion 242 are stacked and spaced apart. The first connection portion 241 is connected to the first surface 2311 of the plastic body 231, and the first connection portion 241 is located in the middle region 2315. The positive projection of the second connection portion 242 on the plastic body 231 at least partially covers the first stop portion 232 and the second stop portion 233. The second connection portion 242 is used to connect to the negative electrode tab of the electrode assembly.

[0090] It can be understood that when the energy storage device 1000 is subjected to an external impact or vibrates during use, the electrode assembly may move back and forth relative to the end cover assembly 200. The movement of the electrode assembly drives the movement of the second connection portion 242 of the current collector member 240, resulting in repeated bending of the bending portion 243. Since the first stop portion 232 and the second stop portion 233 are provided between the second connection portion 242 and the plastic body 231, the first stop portion 232 and the second stop portion 233 can keep a certain gap between the first connection portion 241 and the second connection portion 242 all the time. The existence of the gap can prevent the second connection portion 242 from directly contacting the first connection portion 241, so that the bending angle of the bending portion 243 will not be too large, avoiding the bending portion 243 reaching the metal fatigue limit. Furthermore, it is ensured that the current collector member 240 is not easily broken during use, and the energy storage device 1000 is prevented from failing. Exemplarily, the size of the gap between the first connection portion 241 and the second connection portion 242 can be at least the height of the first stop portion 232 and the second stop portion 233.

[0091] Exemplarily, please refer to Figure 8 and Figure 9 , Figure 9 is Figure 3 Another partial structural schematic diagram of the end cover assembly 200 shown. Both the first stop portion 232 and the second stop portion 233 include at least one stop. The extending direction of the stop is also the extending direction of the first stop portion 232 and the second stop portion 233. The stops included in the first stop portion 232 are the first stop 2321 and the second stop 2322 described below. The stops included in the second stop portion 233 are the third stop 2331 and the fourth stop 2332 described below. The extending direction of the first stop portion 232 along the first surface 2311 can be linear extension or curved extension. The extending direction of the second stop portion 233 along the first surface 2311 is linear extension or curved extension. Exemplarily, as Figure 10 shown, the curved extension can be wavy extension.

[0092] In the first possible implementation manner, please refer to Figure 8, the first bar portion 232 may include a first bar 2321, a second bar 2322, and a first edge bar 2323. The first bar 2321, the second bar 2322, and the first edge bar 2323 extend in the same direction on the first surface 2311. The first bar 2321 is farther from the middle area 2315 of the plastic body 231 than the second bar 2322. That is, the first bar 2321 is located on the side of the second bar 2322 away from the middle area 2315 of the plastic body 231. The first edge bar 2323 is disposed along the circumference of the plastic body 231 on the first surface 2311, and the first edge bar 2323 is located on the side of the first bar 2321 away from the second bar 2322. A first flow channel 2324 is formed between the first bar 2321 and the second bar 2322. A third flow channel 2325 is formed between the first edge bar 2323 and the first bar 2321.

[0093] Please refer to Figure 10 , Figure 10 is Figure 3 Another structural schematic diagram of the lower plastic 230 shown in the first embodiment. The first bar 2321 may include a first end 2326 and a second end 2327 which are oppositely arranged, and the second bar 2322 may include a third end 2328 and a fourth end 2329 which are oppositely arranged. The first end 2326 and the third end 2328 are arranged on the same side, and the second end 2327 and the fourth end 2329 are arranged on the same side. The projection of the first end 2326 on the plastic body 231 has a first distance D1 from the edge of the plastic body 231. The projection of the second end 2327 on the plastic body 231 coincides with the edge of the plastic body 231, and the projection of the third end 2328 on the plastic body 231 coincides with the edge of the plastic body 231. The projection of the fourth end 2329 on the plastic body 231 has a second distance D2 from the edge of the plastic body 231. Wherein, the first distance D1 and the second distance D2 may be the same or different.

[0094] It can be understood that, since there is a first distance D1 between the first end 2326 and the edge of the plastic body 231, there is a gap between the first end 2326 and the housing 100 after the end cap assembly 200 is connected to the housing 100. The first flow channel 2324 and the third flow channel 2325 can communicate through this gap, so that gas can flow from the first flow channel 2324 through this gap to the third flow channel 2325. Since there is a second distance D2 between the fourth end 2329 and the edge of the plastic body 231, there is a gap between the fourth end 2329 and the housing 100 after the end cap assembly 200 is connected to the housing 100. This gap can allow the air flow in the first flow channel 2324 to flow towards the middle area 2315 of the plastic body 231 and can flow to the position where the explosion-proof grid holes 2316 are located. When the internal pressure of the energy storage device 1000 is too high, the explosion-proof valve 220 will be pushed open by the internal air pressure of the energy storage device 1000, and the gas can sequentially pass through the explosion-proof grid holes 2316 on the plastic body 231 and the explosion-proof valve through holes 211 on the end cap 210, thereby completing pressure relief.

[0095] Since the first stop strip portion 232 of the lower plastic 230 can form the first flow channel 2324 and the third flow channel 2325, the gas generated during the use of the energy storage device 1000 can smoothly converge to the explosion-proof grid holes 2316 along the third flow channel 2325 and the first flow channel 2324 in sequence, avoiding the gas from converging to areas other than the explosion-proof grid holes 2316 and being unable to relieve pressure.

[0096] Please refer to Figure 8 and Figure 9 , the first stop strip portion 232 described above extends linearly or curvilinearly on the first surface 2311, that is, the first stop strip 2321 and the second stop strip 2322 extend linearly or curvilinearly on the first surface 2311.

[0097] It can be understood that when the first stop strip 2321 and the second stop strip 2322 extend linearly on the first surface 2311, the first flow channel 2324 between the first stop strip 2321 and the second stop strip 2322 is a linear flow channel. The linear first flow channel 2324 can form a narrow airway, so that the gas generated when the energy storage device 1000 is in use can flow along the first flow channel 2324 to the explosion-proof grid holes 2316, avoiding the gas from directly instantaneously converging and then passing through the explosion-proof grid holes 2316 to impact the explosion-proof valve 220, resulting in misoperation of the explosion-proof valve 220.

[0098] In addition, when the first stop strip 2321 and the second stop strip 2322 extend along a curve on the first surface 2311, the first flow channel 2324 can be arranged in a serpentine shape, and the length of the bent first flow channel 2324 is greater than that of the straight first flow channel 2324. Therefore, the bent first flow channel 2324 can make the flow path of the airflow generated during the use of the energy storage device 1000 longer, so that the process of gas gathering at the explosion-proof grid holes 2316 is slower. Extending the gas gathering time can better avoid the accidental triggering of the explosion-proof valve 220 due to the instantaneous convergence of gas.

[0099] Please refer to Figure 8 , the second stop strip portion 233 can include a third stop strip 2331, a fourth stop strip 2332, and a second edge strip 2333. The third stop strip 2331, the fourth stop strip 2332, and the second edge strip 2333 extend in the same direction on the first surface 2311. The third stop strip 2331 is farther from the middle area 2315 of the plastic body 231 than the fourth stop strip 2332. That is, the third stop strip 2331 is located on the side of the fourth stop strip 2332 away from the middle area 2315 of the plastic body 231. The second edge strip 2333 is arranged along the circumference of the plastic body 231 on the first surface 2311, and the second edge strip 2333 is located on the side of the third stop strip 2331 away from the fourth stop strip 2332. A second flow channel 2334 is formed between the third stop strip 2331 and the fourth stop strip 2332. A fourth flow channel 2335 is formed between the second edge strip 2333 and the third edge strip.

[0100] Please refer to Figure 10 , the third stop strip 2331 can include a fifth end 2336 and a sixth end 2337 arranged oppositely, and the fourth stop strip 2332 can include a seventh end 2338 and an eighth end 2339 arranged oppositely. The fifth end 2336 and the seventh end 2338 are arranged on the same side, and the sixth end 2337 and the eighth end 2339 are arranged on the same side. The projection of the fifth end 2336 on the plastic body 231 has a third distance D3 from the edge of the plastic body 231. The projection of the sixth end 2337 on the plastic body 231 coincides with the edge of the plastic body 231, and the projection of the seventh end 2338 on the plastic body 231 coincides with the edge of the plastic body 231. The projection of the eighth end 2339 on the plastic body 231 has a fourth distance D4 from the edge of the plastic body 231. Among them, the third distance D3 and the fourth distance D4 can be the same or different.

[0101] It can be understood that, since there is a third distance D3 between the fifth end 2336 and the edge of the plastic body 231, there is a gap between the fifth end 2336 and the housing 100 after the end cap assembly 200 is connected to the housing 100. The second flow channel 2334 and the fourth flow channel 2335 can communicate through this gap, so that gas can flow from the second flow channel 2334 through this gap to the fourth flow channel 2335. Since there is a fourth distance D4 between the eighth end 2339 and the edge of the plastic body 231, there is a gap between the eighth end 2339 and the housing 100 after the end cap assembly 200 is connected to the housing 100. This gap can make the airflow in the second flow channel 2334 flow towards the middle area 2315 of the plastic body 231 and can flow to the position where the explosion-proof grid holes 2316 are located. When the internal pressure of the energy storage device 1000 is too high, the explosion-proof valve 220 will be pushed open by the internal air pressure of the energy storage device 1000, and the gas can sequentially pass through the explosion-proof grid holes 2316 on the plastic body 231 and the explosion-proof valve through holes 211 on the end cap 210, thereby completing pressure relief.

[0102] Since the second stop strip portion 233 of the lower plastic 230 can form the second flow channel 2334 and the fourth flow channel 2335, the gas generated during the use of the energy storage device 1000 can smoothly converge to the explosion-proof grid holes 2316 along the fourth flow channel 2335 and the second flow channel 2334 in sequence, avoiding the gas from converging to areas other than the explosion-proof grid holes 2316 and being unable to relieve pressure.

[0103] Please refer to Figure 8 and Figure 9 , the fourth stop strip 2332 portion described above extends linearly or curvilinearly on the first surface 2311, that is, the third stop strip 2331 and the fourth stop strip 2332 extend linearly or curvilinearly on the first surface 2311.

[0104] It can be understood that when the third stop strip 2331 and the fourth stop strip 2332 extend linearly on the first surface 2311, the second flow channel 2334 between the third stop strip 2331 and the fourth stop strip 2332 is a linear flow channel. The linear second flow channel 2334 can form a narrow airway, so that the gas generated during the use of the energy storage device 1000 can flow along the second flow channel 2334 to the explosion-proof grid holes 2316. Avoid the gas from directly and instantaneously converging and then passing through the explosion-proof grid holes 2316 to impact the explosion-proof valve 220, resulting in misoperation of the explosion-proof valve 220.

[0105] In addition, when the third retaining strip 2331 and the fourth retaining strip 2332 extend along a curve on the first surface 2311, the second flow channel 2334 can be arranged in a serpentine shape, and the length of the bent second flow channel 2334 is greater than that of the straight second flow channel 2334. Therefore, the bent second flow channel 2334 can make the flow path of the airflow generated during the use of the energy storage device 1000 longer, so that the process of gas gathering at the explosion-proof grid holes 2316 is slower. Extending the gas gathering time can better avoid the accidental triggering of the explosion-proof valve 220 due to the instantaneous convergence of gas.

[0106] Please refer to Figure 11 , Figure 11 is Figure 10 the schematic cross-sectional view of the lower plastic 230 shown in the figure. In the direction away from the first surface 2311 on the first surface 2311, the widths of the first retaining strip 2321, the second retaining strip 2322, the third retaining strip 2331 and the fourth retaining strip 2332 can gradually become smaller. Alternatively, the widths of the first retaining strip 2321, the second retaining strip 2322, the third retaining strip 2331 and the fourth retaining strip 2332 can become smaller in a gradient manner. The width of the end of the first retaining strip 2321 connected to the first surface 2311 is D5, where 1.5 mm ≥ D5 ≥ 3.5 mm. The width of the end of the first retaining strip 2321 away from the first surface 2311 is D6, where 0.8 mm ≥ D6 ≥ 1.2 mm.

[0107] It can be understood that since the widths of the first retaining strip 2321, the second retaining strip 2322, the third retaining strip 2331 and the fourth retaining strip 2332 at the ends away from the plastic body 231 are smaller, their plastic structures are softer. Therefore, the first retaining strip 2321, the second retaining strip 2322, the third retaining strip 2331 and the fourth retaining strip 2332 can play a buffering role between the plastic body 231 and the second connecting portion 242 of the current collector 240. When the energy storage device 1000 is subjected to an external impact, under the action of inertia, the electrode assembly may approach the lower plastic 230, so that the second connecting portion 242 of the current collector 240 approaches the first connecting portion 241. Since the structures of the ends of the first retaining strip 2321, the second retaining strip 2322, the third retaining strip 2331 and the fourth retaining strip 2332 away from the plastic body 231 are softer, they will play a buffering and supporting role for the second connecting portion 242 and will not cause damage to the second connecting portion 242.

[0108] In addition, since the ends of the first stop strip 2321, the second stop strip 2322, the third stop strip 2331, and the fourth stop strip 2332 that are away from the plastic body 231 can buffer the second connecting portion 242, the external force on the electrode assembly connected to the second connecting portion 242 will also be indirectly relieved, thus preventing the negative electrode tab of the electrode assembly from being deformed due to excessive external force, and further preventing the negative electrode tab from deforming and contacting the positive electrode plate of the electrode assembly after deformation, resulting in a short circuit of the energy storage device 1000 and further causing an explosion.

[0109] Furthermore, since the ends of the first stop strip 2321, the second stop strip 2322, the third stop strip 2331, and the fourth stop strip 2332 that are close to the plastic body 231 are wider, the connection strength between the first stop strip 2321, the second stop strip 2322, the third stop strip 2331, and the fourth stop strip 2332 and the plastic body 231 is relatively high. As a result, the first stop strip 2321, the second stop strip 2322, the third stop strip 2331, and the fourth stop strip 2332 are not easily collapsed under external force, avoiding the failure of the first stop strip 2321, the second stop strip 2322, the third stop strip 2331, and the fourth stop strip 2332 from collapsing after being subjected to external force. And the first stop strip 2321, the second stop strip 2322, the third stop strip 2331, and the fourth stop strip 2332 can provide sufficient buffering force to the second connecting portion 242 of the current collector 240.

[0110] The width of the end of the first stop strip 2321 connected to the first surface 2311 in this application is D5, and 1.5 mm ≥ D5 ≥ 3.5 mm. When the width of the end of the first stop strip 2321 close to the first surface 2311 is too small, the connection strength between the first stop strip 2321 and the plastic body 231 is too low, which will cause the first stop strip 2321 to be easily collapsed under external force. When the width of the end of the first stop strip 2321 close to the first surface 2311 is too large, the first stop strip 2321 will occupy too much space in the first flow channel 2324, so that the gas cannot pass through the first flow channel 2324 smoothly, and then cause the local air pressure in the first flow channel 2324 to be too high, making the energy storage device 1000 have a risk of explosion.

[0111] The width of the end of the first stop strip 2321 away from the first surface 2311 in this application is D6, and 0.8 mm ≥ D6 ≥ 1.2 mm. When the width of the end of the first stop strip 2321 away from the plastic body 231 is too small, the hardness of this end of the first stop strip 2321 is too low to effectively support the current collector 240. When the width of the end of the first stop strip 2321 away from the plastic body 231 is too large, the hardness of this end of the first stop strip 2321 is too high to undergo elastic deformation. Therefore, when the current collector 240 is impacted, the first stop strip 2321 cannot buffer the second connecting portion 242 of the current collector 240 through elastic deformation.

[0112] In the second possible implementation, please refer to Figure 12 , Figure 12 which Figure 3 is a schematic structural view of the lower plastic part 230 in the second implementation. The content identical to that in the first possible implementation will not be elaborated again. Different from the first implementation, the lower plastic part 230 further includes an arc-shaped enclosure 234. Specifically, the arc-shaped enclosure 234 may have four parts, namely the first enclosure 2341, the second enclosure 2342, the third enclosure 2343, and the fourth enclosure 2344.

[0113] The first enclosure 2341 is connected to the first surface 2311 of the plastic body 231 and is arranged along the circumferential direction of the plastic body 231. The first enclosure 2341 may connect one end of the first edge strip 2323 and the second end 2327 of the first stop strip 2321. The second enclosure 2342 is connected to the first surface 2311 of the plastic body 231 and is arranged along the circumferential direction of the plastic body 231. The second enclosure 2342 may connect the other end of the first edge strip 2323 and the third end 2328 of the second stop strip 2322. There is a gap between the second enclosure 2342 and the first end 2326 of the first stop strip 2321.

[0114] It can be understood that the first enclosure 2341 can block one end of the third flow channel 2325, enabling the air flow to flow out from the other end of the third flow channel 2325. The second enclosure 2342 can help the air flow in the third flow channel 2325 to change direction, and the air flow can flow from the third flow channel 2325 to the first flow channel 2324 along the arc of the second enclosure 2342.

[0115] The third enclosure 2343 is connected to the first surface 2311 of the plastic body 231 and is arranged along the circumferential direction of the plastic body 231. The third enclosure 2343 may connect one end of the second edge strip 2333 and the sixth end 2337 of the third stop strip 2331. The fourth enclosure 2344 is connected to the first surface 2311 of the plastic body 231 and is arranged along the circumferential direction of the plastic body 231. The fourth enclosure 2344 may connect the other end of the second edge strip 2333 and the seventh end 2338 of the fourth stop strip 2332. There is a gap between the fourth enclosure 2344 and the fifth end 2336 of the third stop strip 2331.

[0116] It can be understood that the third enclosure 2343 can block one end of the fourth flow channel 2335, enabling the air flow to flow out from the other end of the fourth flow channel 2335. The fourth enclosure 2344 can help the air flow in the fourth flow channel 2335 to change direction, and the air flow can flow from the fourth flow channel 2335 to the second flow channel 2334 along the arc of the fourth enclosure 2344.

[0117] In the third possible implementation, please refer to Figure 13 , Figure 13 whichFigure 3 The structure diagram of the lower plastic 230 in the third embodiment is shown. The same contents as the first possible embodiment are not repeated here. The difference from the first embodiment is that the lower plastic 230 also includes a third bar portion 235. The third bar portion 235 is connected to the first surface 2311, and the third bar portion 235 is located in the middle area 2315. The third bar portion 235 is arranged around the explosion-proof grid hole 2316. The third bar portion 235 can be located between the second pole through hole 2317 and the explosion-proof grid hole 2316. The extension direction of the third bar portion 235 intersects with the extension direction of the first bar portion 232. And the extension direction of the third bar portion 235 intersects with the extension direction of the second bar portion 233. Exemplarily, the direction in which the third bar portion 235 extends is a straight line extension or a curved line extension. The height D8 of the third bar portion 235 ranges from 1.2 mm to 2.5 mm. A height D8 of the third blocking portion 235 is a distance that the third blocking portion 235 extends from the first surface 2311 to a distance away from the first surface 2311 .

[0118] It is understandable that when the internal gas pressure of the energy storage device 1000 is too high and the electrode tabs or insulating films of the electrode assembly are broken, the third blocking bar portion 235 arranged around the anti-through hole can block the broken electrode tabs or insulating films and only allow the airflow to pass through, thereby preventing the broken electrode tabs or insulating films from blocking the explosion-proof grid hole 2316 and causing the explosion-proof valve 220 to fail.

[0119] In addition, the third stop bar 235 is disposed between the first connection portion 241 of the current collector 240 and the plastic body 231. When the height of the third stop bar 235 is too low, it cannot intercept debris. When the height of the third stop bar 235 is too high, the distance between the first connection portion 241 and the plastic body 231 is too large, affecting the connection stability between the first connection portion 241 and the plastic body 231.

[0120] Specifically, the third stop bar portion 235 may include a fifth stop bar 2351, a sixth stop bar 2352, a seventh stop bar 2353 and an eighth stop bar 2354. The fifth stop bar 2351 may be located between the explosion-proof grid hole 2316 and the first stop bar portion 232. The sixth stop bar 2352 is located between the explosion-proof grid hole 2316 and the second stop bar portion 233. The seventh stop bar 2353 and the eighth stop bar 2354 are both located on the side of the explosion-proof grid hole 2316 toward the center of the plastic body 231. The eighth stop bar 2354 is located on the side of the seventh stop bar 2353 away from the explosion-proof grid hole 2316. A fifth flow channel 2355 is formed between the fifth stop bar 2351 and the seventh stop bar 2353. A sixth flow channel 2356 is formed between the sixth stop bar 2352 and the seventh stop bar 2353.

[0121] It can be understood that by arranging the fifth retaining strip 2351 on one side of the explosion-proof grid hole 2316 and forming a fifth flow channel 2355 through the cooperation between the fifth retaining strip 2351 and the seventh retaining strip 2353, the fifth flow channel 2355 can supply the gas on the side of the explosion-proof grid hole 2316 facing the first retaining strip portion 232 to pass through. By arranging the sixth retaining strip 2352 on the other side of the explosion-proof grid hole 2316 and forming a sixth flow channel 2356 through the cooperation between the sixth retaining strip 2352 and the seventh retaining strip 2353, the sixth flow channel 2356 can supply the gas on the side of the explosion-proof grid hole 2316 facing the second retaining strip portion 233 to pass through. That is to say, by sequentially arranging the fifth retaining strip 2351, the seventh retaining strip 2353, and the sixth retaining strip 2352 on the periphery of the explosion-proof grid hole 2316, the fifth retaining strip 2351, the seventh retaining strip 2353, and the sixth retaining strip 2352 can cooperate to surround the explosion-proof grid hole 2316, playing a role in integrating the airflow around the explosion-proof grid hole 2316. In addition, since the fifth flow channel 2355 and the sixth flow channel 2356 are relatively narrow and long, when the broken tab or insulating sheet splashes, it can be blocked by the fifth retaining strip 2351, the sixth retaining strip 2352, and the seventh retaining strip 2353 in the aforementioned flow channels, avoiding the broken tab or insulating sheet on the side of the explosion-proof grid hole 2316 facing the second pole column through hole 2317 from passing through, which is beneficial to avoiding the explosion-proof grid hole 2316 from being blocked by foreign objects and causing the explosion-proof valve 220 to fail.

[0122] Please refer to again Figure 3 and Figure 4 , the pole column 250 is sequentially passed through the first connecting portion 241 of the current collector 240, the second pole column through hole 2317 of the lower plastic 230, and the first pole column through hole 212 of the end cap 210, and protrudes relative to the end cap 210. Specifically, the pole column 250 can pass through the central position of the end cap 210. And the pole column 250 is arranged at an interval from the explosion-proof valve 220.

[0123] The upper plastic 260 is installed between the end cap 210 and the pole column 250, and is located on the side of the end cap 210 facing away from the lower plastic 230. The upper plastic 260 can insulate and isolate the end cap 210 and the pole column 250, and the upper plastic 260 can have a cavity.

[0124] The conductive block is located on the side of the end cap 210 facing away from the lower plastic 230. The voltage-conducting block 270 is sleeved on the circumferential side of the pole column 250 for pressing and fixing the pole column 250. And the voltage-conducting block 270 can be located in the cavity of the upper plastic 260. The circumferential surface of the voltage-conducting block 270 can be in contact with the wall surface of the cavity of the upper plastic 260.

[0125] When assembling the energy storage device 1000, the second connection portion 242 of the current collector 240 in the end cap assembly 200 is welded and fixed to the negative electrode tab in the electrode assembly to achieve electrical connection between the end cap assembly 200 and the electrode assembly. The assembled electrode assembly is placed inside the housing 100. The end cap 210 in the end cap assembly 200 covers the opening of the housing 100, and the lower plastic 230 is also located inside the housing 100. The end cap 210 is welded and sealed to the housing 100 to assemble the energy storage device 1000.

[0126] The embodiments of the present application have been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A end cap assembly (200), characterized in that, Comprising: An end cap (210); A lower plastic part (230), the lower plastic part (230) comprising a plastic body (231), a first bar portion (232) and a second bar portion (233), the plastic body (231) being stacked with the end cap (210), the plastic body (231) comprising a first surface (2311) facing away from the end cap (210), the first bar portion (232) and the second bar portion (233) being provided on the first surface (2311), an intermediate region (2315) being formed between the first bar portion (232) and the second bar portion (233), both the first bar portion (232) and the second bar portion (233) comprising at least one bar, and the width of the end of the bar connected to the plastic body (231) being greater than the width of the end of the bar away from the plastic body (231); and A current collector (240), the current collector (240) comprising a first connection portion (241), a second connection portion (242) and a bending portion (243), the bending portion (243) being connected between the first connection portion (241) and the second connection portion (242), the first connection portion (241) and the second connection portion (242) being stacked and spaced apart, the first connection portion (241) being connected to the first surface (2311), the first connection portion (241) being located in the intermediate region (2315), and the orthographic projection of the second connection portion (242) on the plastic body (231) at least partially covering the first bar portion (232) and the second bar portion (233); A terminal post (250), the terminal post (250) sequentially passing through the first connection portion (241), the lower plastic part (230) and the end cap (210).

2. The end cap assembly (200) according to claim 1, characterized in that, The first bar portion (232) comprises a first bar (2321) and a second bar (2322), the first bar (2321) being located on a side of the second bar (2322) facing away from the intermediate region (2315), and a first flow channel (2324) being formed between the first bar (2321) and the second bar (2322); The second bar portion (233) comprises a third bar (2331) and a fourth bar (2332), the third bar (2331) being located on a side of the fourth bar (2332) facing away from the intermediate region (2315), and a second flow channel (2334) being formed between the third bar (2331) and the fourth bar (2332).

3. The end cap assembly (200) according to claim 2, wherein, The first blocking bar (2321) includes a first end (2326) and a second end (2327) which are arranged opposite to each other, and the second blocking bar (2322) includes a third end (2328) and a fourth end (2329) which are arranged opposite to each other, the first end (2326) and the third end (2328) are arranged on the same side, the second end (2327) and the fourth end (2329) are arranged on the same side, and the projection of the first end (2326) on the plastic body (231) is parallel to the projection of the plastic body (231). The edge of the plastic body (231) has a first distance (D1), the projection of the second end (2327) on the plastic body (231) coincides with the edge of the plastic body (231), the projection of the third end (2328) on the plastic body (231) coincides with the edge of the plastic body (231), and the projection of the fourth end (2329) on the plastic body (231) has a second distance (D2) from the edge of the plastic body (231); The third stop bar (2331) includes a fifth end (2336) and a sixth end (2337) which are arranged opposite to each other. The fourth stop bar (2332) includes a seventh end (2338) and an eighth end (2339) which are arranged opposite to each other. The fifth end (2336) and the seventh end (2338) are arranged on the same side. The sixth end (2337) and the eighth end (2339) are arranged on the same side. The projection of the fifth end (2336) on the plastic body (231) is parallel to the projection of the plastic body (231). The edge of the plastic body (231) has a third distance (D3), the projection of the sixth end (2337) on the plastic body (231) coincides with the edge of the plastic body (231), the projection of the seventh end (2338) on the plastic body (231) coincides with the edge of the plastic body (231), and the projection of the eighth end (2339) on the plastic body (231) has a fourth distance (D4) from the edge of the plastic body (231).

4. The end cap assembly (200) according to claim 3, characterized in that, The first baffle portion (232) further comprises a first edge strip (2323), the first edge strip (2323) being arranged on the first surface (2311) along the circumference of the plastic body (231), the first edge strip (2323) being located on a side of the first baffle (2321) away from the second baffle (2322), and a third flow channel (2325) being formed between the first edge strip (2323) and the first baffle (2321); The second baffle portion (233) includes a second edge strip (2333), the second edge strip (2333) is arranged on the first surface (2311) along the circumference of the plastic body (231), the second edge strip (2333) is located on the side of the third baffle (2331) away from the fourth baffle (2332), and a fourth flow channel (2335) is formed between the second edge strip (2333) and the third baffle (2331).

5. The end cap assembly (200) according to claim 3 or 4, characterized in that, In a direction away from the first surface (2311), the widths of the first stop bar (2321), the second stop bar (2322), the third stop bar (2331), and the fourth stop bar (2332) gradually decrease; or, In a direction away from the first surface (2311), the width gradients of the first stop bar (2321), the second stop bar (2322), the third stop bar (2331), and the fourth stop bar (2332) become smaller.

6. The end cap assembly (200) according to claim 5, characterized in that, The width range (D5) of the end of the first stop bar (2321) connected to the first surface (2311) is between 1.5 mm and 3.5 mm.

7. The end cap assembly (200) according to claim 6, characterized in that, The width range (D6) of the end of the first stop bar (2321) away from the first surface (2311) is between 0.8 mm and 1.2 mm.

8. The end cap assembly (200) according to claim 4, characterized in that, The lower plastic (230) further includes a first enclosing wall (2341) and a second enclosing wall (2342). The first enclosing wall (2341) and the second enclosing wall (2342) are connected to the first surface (2311). One end of the first enclosing wall (2341) is connected to one end of the first edge bar (2323), and the other end of the first enclosing wall (2341) is connected to the second end (2327) of the first stop bar (2321). One end of the second enclosing wall (2342) is connected to the other end of the first edge bar (2323), and the other end of the second enclosing wall (2342) is connected to the third end (2328) of the second stop bar (2322). There is a gap between the second enclosing wall (2342) and the first end (2326). The third flow channel (2325) and the first flow channel (2324) communicate through the gap between the second enclosing wall (2342) and the first end (2326).

9. The end cap assembly (200) according to any one of claims 3, 4, 6, 7, and 8, characterized in that, The lower plastic (230) further includes an explosion-proof grid hole (2316), a pole post through hole, and a third stop bar portion (235). The explosion-proof grid hole (2316) penetrates through the plastic body (231) along the thickness direction of the plastic body (231). Both the explosion-proof grid hole (2316) and the pole post through hole are located in the middle region (2315), and the explosion-proof grid hole (2316) and the pole post through hole are arranged at intervals. The third stop bar portion (235) is connected to the first surface (2311), is located in the middle region (2315), and is provided between the explosion-proof grid hole (2316) and the pole post through hole.

10. The end cap assembly (200) according to claim 9, characterized in that, The extending direction of the third stop bar portion (235) intersects with the extending direction of the first stop bar portion (232), and the extending direction of the third stop bar portion (235) intersects with the extending direction of the second stop bar portion (233).

11. The end cap assembly (200) according to claim 10, wherein, The extending direction of the first stop bar portion (232) is a straight-line extension or a curved extension, the extending direction of the second stop bar portion (233) is a straight-line extension or a curved extension, and the extending direction of the third stop bar portion (235) is a straight-line extension or a curved extension.

12. The end cap assembly (200) according to claim 11, wherein The height (D8) of the third bar portion (235) ranges between 1.2 mm and 2.5 mm.

13. The end cap assembly (200) according to claim 12, wherein, The height (D7) of the first bar portion (232) and the second bar portion (233) ranges between 3.5 mm and 6.5 mm.

14. The end cap assembly (200) according to claim 1, wherein, The lower plastic (230) further includes a limiting rib (2318), the limiting rib (2318) is connected to the first surface (2311) of the plastic body (231), and the limiting rib (2318) is located in the middle area (2315), and the limiting rib (2318) abuts against one side of the first connecting portion (241) of the current collector (240).

15. An energy storage device (1000), characterized in that, Comprising an electrode assembly and an end cap assembly (200) as claimed in any one of claims 1-14, the second connecting portion (242) of the current collector (240) is electrically connected to the electrode assembly.

16. A household energy storage system (1001), characterized in that, Comprising a load (400) and an energy storage device (1000) as claimed in claim 15, the energy storage device (1000) is used to supply power to the load (400).

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