End cover assembly, energy storage device and end cover assembly positioning method

Abstract

An end cap assembly, an energy storage device, and a method for installing and positioning the end cap assembly. The end cap assembly includes an end cap and a current collector plate. The end cap has an explosion-proof valve and a liquid injection hole, and the liquid injection hole and the explosion-proof valve are spaced apart. The current collector plate is coaxially arranged with the end cap. The current collector plate includes a main body portion, and a groove is formed on the surface of the main body portion facing the end cap. A surface identification portion is provided on the main body portion. The surface identification portion has a surface identification feature different from the area other than the surface identification portion on the upper surface of the main body portion. The surface identification feature is used to characterize the surface undulation degree and can be at least recognized or measured by a contact detection device. The liquid injection hole is used to align the end cap and the current collector plate through the surface identification portion. In the end cap assembly, the energy storage device, and the method for installing and positioning the end cap assembly provided by the embodiments of the present application, when the energy storage device is impacted, struck, or dropped, through the shielding and counterattack of the groove, the electrolyte is not easily directly impacted on the explosion-proof valve, reducing the probability that the explosion-proof valve is accidentally triggered due to the impact of the electrolyte.

Description

Technical Field

[0001] This application relates to the technical field of energy storage, and particularly relates to an end cap assembly, an energy storage device, and a positioning method for the end cap assembly. Background Art

[0002] Energy storage devices mainly use chemical elements in batteries as energy storage media. The charge and discharge processes are accompanied by chemical reactions or changes of the energy storage media. Simply put, the electrical energy generated by wind energy and solar energy is stored in chemical batteries, and when the use of external electrical energy reaches a peak, the stored electrical energy is released for use, or transferred to places with a shortage of electrical energy for further use.

[0003] Taking the cylindrical battery in the energy storage device as an example, the cylindrical battery includes a housing, an end cap, and an electrode assembly. Current collectors are welded to both ends of the electrode assembly. The end cap is fixedly connected to the open end of the housing to enclose a sealed cavity. The electrode assembly is located in the sealed cavity. The current collector located at the bottom is welded to the bottom of the housing, and the current collector located at the top is electrically connected to the pole post on the end cap. Among them, an explosion-proof valve is installed on the end cap to play a role in exhausting gas and relieving pressure in time when the air pressure in the sealed cavity increases sharply.

[0004] In the prior art, when the battery is subjected to impact, collision, or drop, the electrolyte in the battery is likely to impact the explosion-proof valve, causing mis-triggering of the explosion-proof valve. During the production and manufacturing process of the battery, it is difficult to accurately align the current collector and the end cap to ensure that the current collector can block the electrolyte impacting the explosion-proof valve, which affects the safety performance and service life of the battery. Summary of the Invention

[0005] The purpose of this application is to provide an end cap assembly, an energy storage device, and a positioning method for the end cap assembly, so as to solve the technical problem in the prior art that it is difficult to accurately align the current collector and the end cap and ensure that the current collector can block the electrolyte impacting the explosion-proof valve.

[0006] To achieve the purpose of this application, the following technical solutions are provided in this application:

[0007] In the first aspect, this application provides an end cap assembly, including:

[0008] An end cap having an explosion-proof valve and a liquid injection hole, and the liquid injection hole is spaced apart from the explosion-proof valve;

[0009] A current collector plate, coaxially arranged with the end cover, the current collector plate includes a main body portion, a groove is formed on the surface of the main body portion facing the end cover, the groove extends from the center of the main body portion to the edge of the main body portion, a surface identification portion is provided on the main body portion, and the surface identification portion has a surface identification feature different from the area other than the surface identification portion on the main body portion. The surface identification feature is used to characterize the surface undulation degree, and the surface identification feature can be at least recognized or measured by a contact detection device;

[0010] Wherein, the liquid injection hole is used to align the end cover and the current collector plate through the surface identification portion, so that the explosion-proof valve and the groove are arranged axially opposite along the current collector plate, and the overlapping area of the positive projection of the explosion-proof valve on the current collector plate and the groove is greater than or equal to 30% of the positive projection area of the explosion-proof valve.

[0011] This embodiment facilitates accurate alignment of the current collector plate and the end cover during the production and manufacturing process of the energy storage device, so that the explosion-proof valve and the groove are axially opposite along the current collector plate, and at least part of the positive projection of the explosion-proof valve on the current collector plate is located in the groove; when the energy storage device is subjected to impact, collision or drop, the electrolyte inside the energy storage device housing will impact the side where the current collector plate and the end cover are located. After being blocked and reflected by the groove, the flow direction of the electrolyte deflects, so that the electrolyte is not easy to directly impact the explosion-proof valve, reducing the pressure on the explosion-proof valve and reducing the probability of the explosion-proof valve being accidentally triggered due to the impact of the electrolyte, which is beneficial to improving the safety performance of the energy storage device and extending the service life of the energy storage device.

[0012] In one embodiment, the surface identification feature of the surface identification portion includes at least one of roughness, texture, and waviness.

[0013] In one embodiment, the roughness of the surface identification portion is greater than the roughness of the area other than the surface identification portion on the main body portion, and the ratio of the roughness of the surface identification portion to the roughness of the area other than the surface identification portion on the main body portion is 1.9 to 3.5.

[0014] This embodiment is beneficial to quickly identify and distinguish the surface identification portion and the area other than the surface identification portion on the main body portion, and improve the detection accuracy.

[0015] In one embodiment, the liquid injection hole is located between the explosion-proof valve and the central axis of the main body portion, and the surface identification portion is located on the bottom wall of the groove. By arranging the surface identification portion on the bottom wall of the groove and aligning the liquid injection hole with the groove, the explosion-proof valve and the groove can be arranged axially opposite to each other along the current collector plate; moreover, when laser welding the electrode assembly and the current collector plate, laser reflection can be avoided, and at the same time, false soldering and wrong soldering can be prevented; since the roughness of the groove is greater than that of the area outside the groove on the main body portion, the friction force of the groove increases, which is also beneficial to improving the welding reliability of the electrode assembly and the current collector plate.

[0016] In one embodiment, the deflection angle of the groove relative to the surface identification portion is the same as the deflection angle of the explosion-proof valve relative to the liquid injection hole;

[0017] When the liquid injection hole and the surface identification portion are arranged axially opposite to each other relative to the current collector plate, the explosion-proof valve and the groove are arranged axially opposite to each other along the current collector plate, and the overlapping area of the orthographic projection of the explosion-proof valve on the current collector plate and the groove is greater than 30% of the orthographic projection area of the explosion-proof valve.

[0018] During the process of aligning the end cap assembly through the liquid injection hole, only by aligning the liquid injection hole with the surface identification portion and making the liquid injection hole and the surface identification portion arranged axially opposite to each other along the current collector plate, the positions of the explosion-proof valve and the groove can be aligned, so that the explosion-proof valve and the groove are arranged axially opposite to each other along the current collector plate, reducing the installation and positioning difficulty of the end cap assembly and being beneficial to quickly completing the alignment of the end cap and the current collector plate.

[0019] In one embodiment, the number of the surface identification portions and the number of the grooves are both multiple, and the multiple surface identification portions and the multiple grooves are alternately distributed one by one on the main body portion.

[0020] By arranging multiple grooves, multiple welding positions are defined, which is convenient for the laser head to align and weld, ensuring the stability and reliability of the connection between the current collector plate and the electrode assembly; by arranging multiple surface identification portions on the main body portion, during the installation process of the end cap assembly, the alignment of the end cap and the current collector plate can be completed by using one of the surface identification portions, reducing the difficulty of aligning the end cap and the current collector plate through the surface identification portion and being beneficial to improving the alignment and installation efficiency of the end cap assembly.

[0021] In one embodiment, the surface identification features of at least two of the surface identification portions are different, which is beneficial to distinguishing the multiple surface identification portions, facilitating the targeted adjustment of the position of the explosion-proof valve relative to the current collector plate according to different surface identification portions, realizing the positioning of the end cap and the current collector plate, and preventing the explosion-proof valve from being accidentally triggered by the impact of the electrolyte.

[0022] In one embodiment, the liquid injection hole and the explosion-proof valve are distributed radially along the end cap, and any one of the grooves is disposed opposite to one of the surface identification portions radially along the current collector plate. Aligning the liquid injection hole with any one of the surface identification portions can make the explosion-proof valve disposed opposite to one of the grooves axially along the current collector plate, reducing the installation and positioning difficulty of the end cap assembly and facilitating the quick alignment of the end cap and the current collector plate.

[0023] In one embodiment, the shape of the surface identification portion is adapted to the shape of the liquid injection hole, which is beneficial to distinguishing the surface identification portion from other regions on the main body portion during the alignment process and quickly identifying the surface identification portion, thereby improving the alignment efficiency of the end cap and the current collector plate.

[0024] In one embodiment, the area of the orthographic projection of the liquid injection hole on the current collector plate is smaller than the area of the surface identification portion, and the ratio of the area of the orthographic projection of the liquid injection hole on the current collector plate to the area of the surface identification portion is 1.41 - 2.22, so that the surface identification portion can be quickly and effectively identified when the current collector plate is identified through the liquid injection hole, which is beneficial to quickly completing the alignment of the end cap and the current collector plate.

[0025] In one embodiment, the main body portion is further provided with a ventilation hole area, the ventilation hole area includes a plurality of through holes arranged at intervals, and the surface identification portion is located in the ventilation hole area. This embodiment increases the gas pressure relief channel, which is beneficial to discharging the gas when the electrode assembly gets out of control, ensuring the gas volume required for the normal opening of the explosion-proof valve, thereby timely relieving the gas pressure through the explosion-proof valve, preventing the internal air pressure of the energy storage device from being too high, and being beneficial to improving the safety and reliability of the energy storage device.

[0026] In one embodiment, the through holes are located on the side of the surface identification portion close to the central axis of the current collector plate, so that the orthographic projection of the liquid injection hole on the current collector plate does not overlap with the through holes, preventing the through holes from affecting the identification effect of the surface identification portion during the positioning process through the liquid injection hole.

[0027] In one embodiment, the overlapping area of the orthographic projection of the explosion-proof valve on the current collector plate and the groove is greater than 80% of the orthographic projection area of the explosion-proof valve, which is beneficial to ensuring the shielding and counterattack effects of the groove on the electrolyte from the electrode assembly and preventing the explosion-proof valve from being accidentally triggered and broken under the impact of the electrolyte.

[0028] In a second aspect, the present application provides an energy storage device, including the end cap assembly provided in any one of the embodiments of the first aspect.

[0029] In a third aspect, the present application provides a method for positioning an end cap assembly, which is applied to the end cap assembly provided in any one of the embodiments of the first aspect. The method for positioning the end cap assembly includes:

[0030] Adjust the position of the explosion-proof valve relative to the current collector plate according to the surface recognition features of the surface recognition part, and determine that the explosion-proof valve and the groove are arranged axially opposite to each other along the current collector plate.

[0031] In one embodiment, the deflection angle of the groove relative to the surface recognition part is the same as the deflection angle of the explosion-proof valve relative to the liquid injection hole;

[0032] The determination that the explosion-proof valve and the groove are arranged axially opposite to each other along the current collector plate specifically includes:

[0033] Determine that the liquid injection hole is aligned with the surface recognition part.

[0034] In one embodiment, the surface recognition features include at least one of roughness, texture, and waviness;

[0035] The determination that the liquid injection hole is aligned with the surface recognition part specifically includes:

[0036] Determine that the surface recognition features of the area aligned with the liquid injection hole are the surface recognition features of the surface recognition part.

[0037] In one embodiment, the roughness of the surface recognition part is greater than or equal to a preset roughness, and the roughness of the area other than the surface recognition part on the main body part is less than the preset roughness;

[0038] The determination that the surface recognition features of the area aligned with the liquid injection hole are the surface recognition features of the surface recognition part includes:

[0039] Determine that the roughness of the area aligned with the liquid injection hole is greater than the preset roughness.

[0040] The end cap assembly, energy storage device, and end cap assembly installation and positioning method provided by the present application use the surface recognition part to align the end cap and the current collector plate by setting the liquid injection hole, which is convenient for accurately aligning the current collector plate and the end cap during the production and manufacturing process of the energy storage device, so that the explosion-proof valve and the groove are arranged axially opposite to each other along the current collector plate, and at least part of the orthographic projection of the explosion-proof valve on the current collector plate is located in the groove; when the energy storage device is subjected to impact, collision or drop, the electrolyte inside the energy storage device housing will impact towards the side where the current collector plate and the end cap are located. After being blocked and reflected by the groove, the flow direction of the electrolyte deflects, making it difficult for the electrolyte to directly impact the explosion-proof valve, reducing the pressure on the explosion-proof valve, and reducing the probability of the explosion-proof valve being accidentally triggered due to the impact of the electrolyte, which is beneficial to improving the safety performance of the energy storage device and extending the service life of the energy storage device. Description of the Drawings

[0041] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0042] Figure 1 is a schematic structural diagram of a household energy storage system of an embodiment;

[0043] Figure 2 is a schematic structural diagram of an end cap assembly of an embodiment;

[0044] Figure 3 is a schematic structural diagram of an end cap of an embodiment;

[0045] Figure 4 is a schematic structural diagram of an end cap of another embodiment;

[0046] Figure 5 is a schematic structural diagram of a current collector plate of an embodiment;

[0047] Figure 6 is a schematic diagram of the relative position of a current collector plate and an explosion-proof valve of an embodiment;

[0048] Figure 7 is a schematic flow diagram of a method for installing and positioning an end cap assembly of an embodiment.

[0049] Explanation of reference numerals:

[0050] 100 - energy storage device; 200 - power conversion device; 300 - user load; 1 - end cap; 11 - explosion-proof valve; 12 - liquid injection hole; 13 - mounting hole; 2 - current collector plate; 21 - main body part; 22 - groove; 23 - ventilation hole area; 231 - through hole; 24 - boss; 25 - surface identification part. Specific embodiments

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0052] It should be noted that when a component is referred to as "fixed to" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time.

[0053] In this application, unless otherwise clearly defined and limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or capable of communicating with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0054] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of this application in the specification are only for the purpose of describing specific embodiments, and are not intended to limit this application. The term "and / or" used in this application includes any and all combinations of one or more of the related listed items.

[0055] In the description of the embodiments of this application, it should be noted that the orientation or positional relationship indicated by terms such as "center", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0056] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0057] The following will describe in detail some embodiments of this application with reference to the drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0058] 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 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.

[0059] 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 grid instability, insufficient electricity during peak demand, and too much electricity during off-peak demand. The unstable voltage will also damage the electricity. Therefore, the problem of "abandoning wind and light" may be caused by insufficient electricity demand or insufficient grid acceptance capacity. To solve these problems, energy storage is required, that is, converting electrical energy into other forms of energy through physical or chemical means and storing it, and converting the energy into electrical energy and releasing it when needed. Simply put, energy storage is similar to a large "power bank", which stores electrical energy when photovoltaic and wind energy are sufficient and releases the stored electricity when needed.

[0060] Taking electrochemical energy storage as an example, the embodiment of the present application provides an energy storage device 100. A chemical battery is provided in the energy storage device 100, 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 electrical 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 tight electricity for further use.

[0061] Currently, the application scenarios of energy storage (i.e., energy storage) are relatively wide, 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 100 include:

[0062] (1) A large energy storage container applied to the grid side energy storage scenario, which can be used as a high-quality active and reactive power regulation power source in the grid, achieve load matching of electrical energy in time and space, enhance the consumption capacity of renewable energy, and is of great significance in grid system standby, alleviating the power supply pressure during peak loads, and peak shaving and frequency modulation.

[0063] (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; during the peak electricity price period, they release the electricity in the energy storage device for use 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.

[0064] The embodiments of the present application are described by taking the household energy storage scenario in user-side energy storage as an example. The energy storage device 100 provided by the embodiments of the present application is not limited to the household energy storage scenario.

[0065] The embodiments of the present application provide a household energy storage system, as Figure 1 shown. The household energy storage system includes an electric energy conversion device 200, a user load 300, etc., and an energy storage device 100. The energy storage device 100 is a small energy storage box and can be installed on an outdoor wall by wall mounting. The user load 300 can be a street lamp or household appliances, etc. Specifically, the electric energy conversion device 200 can be a photovoltaic panel, and the photovoltaic panel can convert solar energy into electric energy during the low electricity price period. The energy storage device 100 is used to store the electric energy and supply it to the street lamp and household appliances for use during the peak electricity price period, or supply power when the power grid is powered off / out of power.

[0066] It can be understood that the energy storage device 100 may include but is not limited to single cells, battery modules, battery packs, battery systems, etc. When the energy storage device 100 is a single cell, it can be a cylindrical battery or a square battery.

[0067] The present application provides an electrical device including an energy storage device 100, and the energy storage device 100 is used to supply power to the electrical device. The electrical device can include a user load 300 or a vehicle, an electronic device, a household appliance, etc.

[0068] Specifically, the energy storage device 100 includes an end cover assembly, an electrode assembly, and a housing. The electrode assembly is located in the space surrounded by the housing. The end cover 1 of the end cover assembly is connected to the housing and is used to close one opening of the housing.

[0069] Specifically, as Figure 2As shown in the figure, the end cap assembly provided by the present application includes an end cap 1 and a current collector plate 2. The end cap 1 has an explosion-proof valve 11 and a liquid injection hole 12, and the liquid injection hole 12 and the explosion-proof valve 11 are distributed at intervals. The current collector plate 2 is coaxially arranged with the end cap 1. The current collector plate 2 includes a main body portion 21. A groove 22 is formed on the surface of the main body portion 21 facing the end cap 1, and the groove 22 extends from the center of the main body portion 21 to the edge of the main body portion 21. A surface identification portion 25 is provided on the main body portion 21. The surface identification portion 25 has surface identification features different from the regions other than the surface identification portion 25 on the upper surface of the main body portion 21. The surface identification features are used to characterize the surface undulation degree, and the surface identification features can be at least recognized or measured by a contact detection device.

[0070] By setting the surface identification features of the surface identification portion 25 to be different from those of the regions other than the surface identification portion 25 on the main body portion 21, the surface undulation degrees of the surface identification portion 25 and the regions other than the surface identification portion 25 on the main body portion 21 are different. The current collector plate 2 can be detected by a contact detection device to identify or measure the surface identification features of different regions, or the surface identification features can be identified or measured by a non-contact detection device, or can also be identified manually. Exemplarily, the contact detection device can be an instrument that detects according to the principle of needle tracing method, and a stylus is used to gently slide on the measured surface for identification or measurement; the non-contact detection device uses principles such as interference method and optical section method for detection and does not need to contact the measured surface; it can also be identified manually by using the vision and touch of the human body.

[0071] Among them, the liquid injection hole 12 is used to align the end cap 1 and the current collector plate 2 through the surface identification portion 25, so that the explosion-proof valve 11 and the groove 22 are arranged opposite to each other along the axial direction of the current collector plate 2, and the overlapping area of the orthographic projection of the explosion-proof valve 11 on the current collector plate 2 and the groove 22 is greater than or equal to 30% of the orthographic projection area of the explosion-proof valve 11.

[0072] Exemplarily, the end cap assembly provided by the embodiments of the present application is used for a cylindrical battery. The cylindrical battery includes a housing and an electrode assembly. Both ends of the electrode assembly are respectively welded to a current collector plate 2. The end cap 1 is fixedly connected to the open end of the housing to enclose a sealed cavity. The electrode assembly is located in the sealed cavity. One current collector plate is welded to the bottom of the housing, and the other current collector plate is electrically connected to the pole post on the end cap 1. The groove 22 on the current collector plate can directly and tightly abut against the toppled tab on the electrode assembly, avoiding poor contact between the tab and the current collector plate 2 during laser welding, which may cause false soldering. The groove 22 also defines the welding position, facilitating the alignment and welding of the laser head. The groove 22 provides a physical space cavity for accommodating the fine metal particles generated during welding, preventing them from splashing around and falling into the electrode assembly, which may cause internal short circuit of the battery. The current collector plate 2 provided by the embodiments of the present application can be a positive current collector plate or a negative current collector plate, which can be flexibly selected according to actual needs. For example, when the current collector plate 2 is made of aluminum, it can be used as a positive current collector plate and welded to the aluminum end cap 1.

[0073] As Figure 5 shown, the main body 21 of the current collector plate 2 can be in the shape of a circular flat plate, so that the current collector plate 2 can be adapted to the cross-sectional shape of the housing of the cylindrical battery, and thus can be widely used in cylindrical batteries, which is conducive to realizing the attachment between the wound electrode assembly and the current collector plate 2, and between the end cap 1 and the current collector plate 2, ensuring the sealed connection between the current collector plate 2 and the housing of the cylindrical battery.

[0074] When the energy storage device 100 malfunctions, a large amount of gas will be generated in the sealed cavity of the energy storage device 100, causing the air pressure in the sealed cavity of the energy storage device 100 to increase sharply. If the large amount of gas in the sealed cavity of the energy storage device 100 is not discharged in time, the energy storage device 100 is likely to explode, resulting in a safety accident. By providing an explosion-proof valve 11 on the end cap 1, the gas in the sealed cavity of the energy storage device 100 can be discharged in time, reducing the safety risk. Exemplarily, the explosion-proof valve 11 is in the shape of a sheet, and a stress-weakened area is provided on the explosion-proof valve 11. When the pressure exerted by the air pressure in the sealed cavity of the energy storage device 100 on the explosion-proof valve 11 reaches the maximum pressure that the stress-weakened area can withstand, the stress-weakened area of the explosion-proof valve 11 will rupture, thereby discharging the large amount of gas in the sealed cavity and relieving the pressure of the sealed cavity in time.

[0075] The main body portion 21 has a first surface and a second surface that face away from each other. Specifically, in the case where the end cap assembly is assembled to the energy storage device 100, the first surface is the surface on the side facing away from the electrode assembly, and the second surface of the main body portion 21 is the surface on the side facing the electrode assembly. The groove 22 is recessed in the main body portion 21. The groove 22 is strip-shaped and extends from the central axis of the main body portion 21 towards the edge of the main body portion 21. Among them, the groove 22 is used to provide a welding space for the current collector plate 2 and the electrode assembly. The groove 22 is recessed relative to the first surface. The groove 22 extends in the radial direction of the main body portion 21. The groove 22 can be obtained by stamping the first surface of the main body portion 21, and a protrusion is formed on the second surface accordingly.

[0076] The liquid injection hole 12 is used to align the end cap 1 and the current collector plate 2 through the surface recognition portion 25 during the installation process of the end cap assembly. Since the surface recognition portion 25 is provided on the main body portion 21, and the surface recognition portion 25 has surface recognition features different from the regions other than the surface recognition portion 25 on the upper surface of the main body portion 21, the end cap 1 and the current collector plate 2 can be aligned based on the recognition, distinction, or judgment of the surface recognition portion 25. Exemplarily, the surface features of the current collector plate 2 can be recognized, distinguished, or judged through the liquid injection hole 12, and the position of the explosion-proof valve 11 relative to the current collector member can be adjusted to ensure that the explosion-proof valve 11 and the groove 22 are arranged axially opposite to each other along the current collector plate 2, and at least part of the orthographic projection of the explosion-proof valve 11 on the current collector plate 2 is located in the groove 22. It can be understood that the orthographic projection of the explosion-proof valve 11 on the current collector plate 2 is the projection of the explosion-proof valve 11 along the direction parallel to the central axis of the current collector plate 2 and pointing from the end cap 1 to the current collector plate 2. As Figure 6 shown, when observed along the axial direction of the current collector plate 2, the explosion-proof valve 11 and the groove 22 at least partially overlap. When the energy storage device 100 is subjected to impacts such as impacts and drops, if the electrolyte infiltrating the electrode assembly generates a moving impact from the position where the electrode assembly is located towards the position where the explosion-proof valve 11 is located, the electrolyte will be blocked by the groove 22. The groove 22 bears part of the impact caused by the electrolyte, plays a buffering role for the explosion-proof valve 11, reduces the impact pressure on the explosion-proof valve 11 from the electrolyte, prevents the explosion-proof valve 11 from being accidentally triggered and broken under the impact of the electrolyte, is beneficial to improving the safety performance of the energy storage device 100, and extends the service life of the energy storage device 100.

[0077] As Figure 4 and Figure 5 shown, an installation hole 13 is opened at the central axis position of the end cap 1, and a boss 24 protruding outward relative to the first surface is provided at the central axis position of the current collector plate 2. The boss 24 is inserted into the installation hole 13 to realize the connection between the end cap 1 and the current collector plate 2. Optionally, the boss 24 is rotatably inserted into the installation hole 13, so that the end cap 1 and the current collector plate 2 can rotate relative to each other, which is convenient for adjusting the relative position of the explosion-proof valve 11 relative to the current collector plate 2.

[0078] The end - cover assembly provided by this application uses the liquid injection hole 12 and the surface recognition part 25 to align the end - cover 1 and the current - collecting plate 2. This facilitates the accurate alignment of the current - collecting plate 2 and the end - cover 1 during the production and manufacturing process of the energy - storage device 100, so that the explosion - proof valve 11 and the groove 22 are arranged opposite to each other along the axial direction of the current - collecting plate 2, and at least part of the orthographic projection of the explosion - proof valve 11 on the current - collecting plate 2 is located in the groove 22. When the energy - storage device 100 is subjected to impact, collision or drop, the electrolyte inside the housing of the energy - storage device 100 will impact towards the side where the current - collecting plate 2 and the end - cover 1 are located. After being blocked and reflected by the groove 22, the flow direction of the electrolyte deflects, making it difficult for the electrolyte to directly impact the explosion - proof valve 11, reducing the pressure on the explosion - proof valve 11, and decreasing the probability of the explosion - proof valve 11 being accidentally triggered due to the impact of the electrolyte. This is beneficial to improving the safety performance of the energy - storage device 100 and extending the service life of the energy - storage device 100.

[0079] In a further embodiment, the overlapping area of the orthographic projection of the explosion - proof valve 11 on the current - collecting plate 2 and the groove 22 is greater than 80% of the orthographic projection area of the explosion - proof valve 11. In this embodiment, by setting the overlapping area of the orthographic projection of the explosion - proof valve 11 and the groove 22 to be greater than 80% of the orthographic projection area of the explosion - proof valve 11, it is beneficial to ensure the blocking and reflecting effect of the groove 22 on the electrolyte from the electrode assembly, and prevent the explosion - proof valve 11 from being accidentally triggered and broken under the impact of the electrolyte.

[0080] In a specific embodiment, the surface recognition features of the surface recognition part 25 include at least one of roughness, texture, and waviness. It should be noted that roughness refers to the unevenness of the processed surface with smaller spacing and minute peaks and valleys; texture refers to the uneven grooves, patterns, etc. on the surface of an object; waviness refers to the unevenness of the processed surface with a spacing larger than the surface roughness but smaller than the surface geometric shape error. The surface recognition features of the surface recognition part 25 and the area outside the surface recognition part 25 on the upper surface of the main body part 21 can be distinguished by a contact - type detection device and can also be distinguished by human touch. Optionally, they can also be distinguished by a non - contact - type detection device to distinguish the two areas.

[0081] Exemplarily, the texture of the surface recognition part 25 is different from the texture of the area outside the surface recognition part 25 on the upper surface of the main body part 21. For example, the surface recognition part 25 is provided with a plurality of outward - protruding ridges to form a strip - shaped texture, and the area outside the surface recognition part 25 on the upper surface of the main body part 21 is a smooth plane. When the detection device determines that the area where the liquid injection hole 12 is aligned has a strip - shaped texture, it can be determined that the area where the liquid injection hole 12 is aligned is the surface recognition part 25, and then the relative position of the explosion - proof valve 11 with respect to the current - collecting plate 2 can be determined, which is convenient for further adjusting the relative setting of the explosion - proof valve 11 and the groove 22 along the axial direction of the current - collecting plate 2 to complete the positioning of the end - cover 1 and the current - collecting plate 2.

[0082] Exemplarily, the waviness of the surface recognition portion 25 is different from that of the area other than the surface recognition portion 25 on the upper surface of the main body portion 21. For example, the surface recognition portion 25 has a continuous surface with a wavy undulation, and the area other than the surface recognition portion 25 on the upper surface of the main body portion 21 is a smooth plane. The waviness of the surface recognition portion 25 is greater than that of the area other than the surface recognition portion 25 on the upper surface of the main body portion 21. When the detection device determines that the waviness of the area aligned with the liquid injection hole 12 is large, it can be determined that the area aligned with the liquid injection hole 12 is the surface recognition portion 25, and then the relative position of the explosion-proof valve 11 relative to the current collector plate 2 can be determined, which is convenient for further adjusting the relative arrangement of the explosion-proof valve 11 and the groove 22 along the axial direction of the current collector plate 2 to complete the positioning of the end cap 1 and the current collector plate 2.

[0083] Exemplarily, the roughness of the surface recognition portion 25 is different from that of the area other than the surface recognition portion 25 on the upper surface of the main body portion 21. For example, the surface recognition portion 25 is provided with particles, and the area other than the surface recognition portion 25 on the upper surface of the main body portion 21 is a smooth plane. The roughness of the surface recognition portion 25 is greater than that of the area other than the surface recognition portion 25 on the upper surface of the main body portion 21. When the detection device determines that the roughness of the area aligned with the liquid injection hole 12 is large, it can be determined that the area aligned with the liquid injection hole 12 is the surface recognition portion 25, and then the relative position of the explosion-proof valve 11 relative to the current collector plate 2 can be determined, which is convenient for further adjusting the relative arrangement of the explosion-proof valve 11 and the groove 22 along the axial direction of the current collector plate 2 to complete the positioning of the end cap 1 and the current collector plate 2.

[0084] In a further embodiment, when the roughness of the surface recognition portion 25 is greater than that of the area other than the surface recognition portion 25 on the upper surface of the main body portion 21, the ratio of the roughness of the surface recognition portion 25 to that of the area other than the surface recognition portion 25 on the upper surface of the main body portion 21 is 1.9 to 3.5. For example, the roughness of the surface recognition portion 25 can be 6.4 μm, 12 μm, or any value between 6.4 μm and 12 μm. By setting the ratio of the roughness of the surface recognition portion 25 to that of the area other than the surface recognition portion 25 on the upper surface of the main body portion 21 to be 1.9 to 3.5, it is beneficial to quickly identify and distinguish the surface recognition portion 25 and the area other than the surface recognition portion 25 on the upper surface of the main body portion 21, and improve the detection accuracy.

[0085] Based on the above embodiments, the liquid injection hole 12 is located between the central axis of the explosion-proof valve 11 and the main body portion 21, and the surface recognition portion 25 is located on the bottom wall of the groove 22. As Figure 3As shown, the liquid injection hole 12 and the explosion-proof valve 11 are located on the same side of the central axis of the main body portion 21. When the surface identification portion 25 is located on the bottom wall of the groove 22, as long as the liquid injection hole 12 is aligned with the groove 22, it can be ensured that the explosion-proof valve 11 and the groove 22 are arranged axially opposite to each other along the current collector plate 2, which is convenient for positioning the end cover 1 and the current collector plate 2. It can be understood that at least part of the bottom wall of the groove 22 includes the surface identification portion 25. For example, the roughness of the bottom wall of the groove 22 is greater than the roughness of the area outside the groove 22 on the main body portion of the groove 22, and the surface identification portion 25 is the entire area of the bottom wall of the groove 22. It should be noted that there is an appropriate gap between the liquid injection hole 12 and the explosion-proof valve 11 to avoid interference between the liquid injection device and the explosion-proof valve 11 during the liquid injection process.

[0086] By setting the surface identification portion 25 on the bottom wall of the groove 22 and aligning the liquid injection hole 12 with the groove 22, the explosion-proof valve 11 and the groove 22 can be arranged axially opposite to each other along the current collector plate 2; moreover, when laser welding the electrode assembly and the current collector plate 2, laser reflection can be avoided, and at the same time, false soldering and wrong soldering can be prevented; since the roughness of the groove 22 is greater than the roughness of the area outside the groove 22 on the main body portion 21, the friction force of the groove 22 increases, which is also beneficial to improving the welding reliability of the electrode assembly and the current collector plate 2.

[0087] In another embodiment, the liquid injection hole 12 is located at a position outside the area between the explosion-proof valve 11 and the central axis of the main body portion 21, and the deflection angle of the groove 22 relative to the surface identification portion 25 is the same as the deflection angle of the explosion-proof valve 11 relative to the liquid injection hole 12. When the liquid injection hole 12 and the surface identification portion 25 are arranged axially opposite to each other along the current collector plate 2, the explosion-proof valve 11 and the groove 22 are arranged axially opposite to each other along the current collector plate 2, and the overlapping area of the positive projection of the explosion-proof valve 11 on the current collector plate 2 and the groove 22 is greater than 30% of the positive projection area of the explosion-proof valve 11.

[0088] It can be understood that the deflection angle of the groove 22 relative to the surface identification portion 25 is the angle between the line connecting the geometric center of the groove 22 and the central axis of the current collector plate 2 and the line connecting the geometric center of the surface identification portion 25 and the central axis of the current collector plate 2. The deflection angle of the explosion-proof valve 11 relative to the liquid injection hole 12 is the angle between the line connecting the geometric center of the explosion-proof valve 11 and the central axis of the end cap 1 and the line connecting the central axis of the liquid injection hole 12 and the central axis of the end cap 1. It should be noted that the deflection angle is a vector with both magnitude and direction. The deflection angle of the groove 22 relative to the surface identification portion 25 is the same as the deflection angle of the explosion-proof valve 11 relative to the liquid injection hole 12, that is, the deflection direction of the groove 22 relative to the surface identification portion 25 is the same as the deflection direction of the explosion-proof valve 11 relative to the liquid injection hole 12, and the deflection angle of the groove 22 relative to the surface identification portion 25 is the same as the deflection angle of the explosion-proof valve 11 relative to the liquid injection hole 12. Among them, both the groove 22 and the surface identification portion 25 can be one or more. In the case where both the groove 22 and the surface identification portion 25 are multiple, aligning the liquid injection hole 12 with any one of the surface identification portions 25 can complete the alignment of the end cap 1 and the current collector plate 2, reducing the installation and positioning difficulty of the end cap assembly and facilitating improving the production efficiency of the end cap assembly.

[0089] By setting the deflection angle of the groove 22 relative to the surface identification portion 25 to be the same as the deflection angle of the explosion-proof valve 11 relative to the liquid injection hole 12, during the process of aligning the end cap assembly through the liquid injection hole 12, only by aligning the liquid injection hole 12 with the surface identification portion 25 and making the liquid injection hole 12 and the surface identification portion 25 be axially opposite to each other along the current collector plate 2 can the positions of the explosion-proof valve 11 and the groove 22 be aligned, making the explosion-proof valve 11 and the groove 22 be axially opposite to each other along the current collector plate 2, reducing the installation and positioning difficulty of the end cap assembly and facilitating quickly completing the alignment of the end cap 1 and the current collector plate 2.

[0090] In one embodiment, the numbers of both the surface identification portion 25 and the groove 22 are multiple, and the multiple surface identification portions 25 and the multiple grooves 22 are alternately distributed one by one on the main body portion 21. Specifically, the multiple grooves 22 are circumferentially spaced apart on the main body portion 21, and one surface identification portion 25 is provided between any two adjacent grooves 22. For example Figure 6 As shown, both the groove 22 and the surface identification portion 25 are three, and the three grooves 22 and the three surface identification portions 25 are alternately distributed one by one on the main body portion 21. By providing multiple grooves 22, multiple welding positions are defined, facilitating the laser head to align and weld, ensuring the stability and reliability of the connection between the current collector plate 2 and the electrode assembly; by providing multiple surface identification portions 25 on the main body portion 21, during the installation process of the end cap assembly, the alignment of the end cap 1 and the current collector plate 2 can be completed by using one of the surface identification portions 25, reducing the difficulty of aligning the end cap 1 and the current collector plate 2 through the surface identification portion 25 and facilitating improving the alignment and installation efficiency of the end cap assembly.

[0091] Further, among the multiple surface recognition parts 25, the surface recognition features of at least two surface recognition parts 25 are different. Among them, the difference in visual recognition features can be manifested as different forms of the same type of visual recognition feature. For example, some of the surface recognition parts 25 have larger-diameter particles, and other surface recognition parts 25 have smaller-diameter particles to present different roughnesses; the difference in surface recognition features can also be manifested as having different types of surface recognition features. For example, some of the surface recognition parts 25 are provided with particles, and other surface recognition parts 25 have a wavy surface.

[0092] By setting the surface recognition features of at least two surface recognition parts 25 to be different, it is beneficial to distinguish the multiple surface recognition parts 25, facilitate the targeted adjustment of the position of the explosion-proof valve 11 relative to the manifold 2 according to different surface recognition parts 25, realize the positioning of the end cap 1 and the manifold 2, and prevent the explosion-proof valve 11 from being accidentally triggered by the impact of the electrolyte.

[0093] In a specific embodiment, the liquid injection hole 12 and the explosion-proof valve 11 are distributed along the radial direction of the end cap 1. The liquid injection hole 12 and the explosion-proof valve 11 are respectively located on both sides of the central axis of the main body part 21. Any groove 22 is arranged opposite to a surface recognition part 25 along the radial direction of the manifold 2, and the groove 22 and the surface recognition part 25 are located on both sides of the central axis of the main body part 21. As Figure 4 shown, the connection line between the liquid injection hole 12 and the central axis of the end cap 1 and the connection line between the explosion-proof valve 11 and the central axis of the end cap 1 are on the same straight line, and the included angle between the liquid injection hole 12 and the explosion-proof valve 11 is 180°. As Figure 5 shown, there are three grooves 22 and three surface recognition parts 25. The three grooves 22 and the three surface recognition parts 25 are evenly distributed on the main body part 21, and the three grooves 22 and the three surface recognition parts 25 are alternately distributed one by one on the main body part 21. Any groove 22 is arranged opposite to one of the surface recognition parts 25 along the radial direction of the manifold 2. In this embodiment, when the liquid injection hole 12 is aligned with any one of the surface recognition parts 25, the explosion-proof valve 11 can be arranged opposite to one of the grooves 22 along the axial direction of the manifold 2, reducing the installation and positioning difficulty of the end cap assembly and facilitating the quick alignment of the end cap 1 and the manifold 2.

[0094] In an embodiment, the shape of the surface recognition part 25 is adapted to the shape of the liquid injection hole 12. For example, when the liquid injection hole 12 is a circular hole, the surface recognition part 25 is also circular. By setting the shape of the surface recognition part 25 to be adapted to the shape of the liquid injection hole 12, it is beneficial to distinguish the surface recognition part 25 from other areas on the main body part 21 during the alignment process and quickly identify the surface recognition part 25, improving the alignment efficiency of the end cap 1 and the manifold 2.

[0095] Furthermore, the orthographic projection area of the injection hole 12 on the collecting plate 2 is smaller than the area of the surface identification portion 25, and the ratio of the orthographic projection area of the injection hole 12 on the collecting plate 2 to the area of the surface identification portion 25 is 1.41 to 2.22, so that the surface identification portion 25 can be quickly and effectively identified when the collecting plate 2 is identified through the injection hole 12, which is conducive to quickly completing the alignment of the end cover 1 and the collecting plate 2.

[0096] The main body 21 is also provided with a vent area 23, which includes a plurality of through holes 231 arranged at intervals, and the surface identification part 25 is located in the vent area 23. The through holes 231 run through the thickness direction of the main body 21. By providing the vent area 23, a gas pressure relief channel is added, which is conducive to the gas being discharged when the electrode assembly is out of control, and the amount of gas required for the normal opening of the explosion-proof valve 11 is ensured, so that the gas pressure is relieved in time through the explosion-proof valve 11, and the internal gas pressure of the energy storage device 100 is prevented from being too high, which is conducive to improving the safety and reliability of the energy storage device 100.

[0097] The plurality of through holes 231 may be distributed in an array on the main body 21 to improve the uniformity and timeliness of the pressure relief of the gas pressure relief channel. For example, the plurality of through holes 231 may be distributed in an annular shape on the main body 21; or, for another example, the plurality of through holes 231 may be distributed in a row along the radial direction of the main body on the main body 21. In a specific embodiment, Figure 5 As shown, the air hole area 23 includes eight through holes 231, and the eight through holes 231 are distributed in a rectangular array.

[0098] Optionally, the inner diameter of the through hole 231 is larger than the inner diameter of the injection hole 12. During the process of injecting liquid into the electrode assembly through the injection hole 12, the injection hole 12 can be coaxially aligned with one of the through holes 231, and the electrolyte can be directly injected into the electrode assembly through the collecting plate 2 to improve the injection efficiency.

[0099] In a further embodiment, the through hole 231 is located on one side of the surface identification portion 25 close to the central axis of the collecting plate 2, so that the orthographic projection of the injection hole 12 on the collecting plate 2 does not overlap with the through hole 231, thereby preventing the through hole 231 from affecting the recognition effect of the surface identification portion 25 during the positioning process through the injection hole 12.

[0100] Optionally, the shape of the surface identification portion 25 is different from the shape of the through hole 231. For example, when the through hole 231 is a circular hole, the surface identification portion 25 is in an elliptical, rectangular or other shape different from a circular shape. By setting the shape of the surface identification portion 25 to be different from the shape of the through hole 231, it is helpful to distinguish the surface identification portion 25 from the through hole 231 during the alignment process, and quickly identify the surface identification portion 25, thereby improving the alignment efficiency of the end cover 1 and the current collecting plate 2.

[0101] The present application further provides a method for installing and positioning an end cover assembly, which is applied to the end cover assembly provided in any of the above embodiments. As Figure 7 shown, the method includes:

[0102] S10: Adjust the position of the explosion-proof valve 11 relative to the current collector plate 2 according to the surface recognition feature of the surface recognition part 25, and determine that the explosion-proof valve 11 and the groove 22 are arranged opposite to each other along the axial direction of the current collector plate 2.

[0103] The end cover assembly includes an end cover 1 and a current collector plate 2. The end cover 1 has an explosion-proof valve 11 and a liquid injection hole 12, and the liquid injection hole 12 and the explosion-proof valve 11 are distributed at intervals. The current collector plate 2 is coaxially arranged with the end cover 1. The current collector plate 2 includes a main body portion 21. A groove 22 is formed on the surface of the main body portion 21 facing the end cover 1, and the groove 22 extends from the center of the main body portion 21 to the edge of the main body portion 21. A surface recognition part 25 is provided on the main body portion 21. The surface recognition part 25 has a surface recognition feature different from the area other than the surface recognition part 25 on the upper surface of the main body portion 21. The surface recognition feature is used to characterize the surface undulation degree, and the surface recognition feature can be at least recognized or measured by a contact detection device.

[0104] In step S10, at least a contact detection device is used to recognize or measure the surface recognition feature. Based on the recognition or measurement of the surface recognition feature, the position of the explosion-proof valve 11 relative to the current collector plate 2 is adjusted manually or by a driving device. Specifically, the position of the explosion-proof valve 11 relative to the groove 22 on the current collector plate 2 is adjusted until the explosion-proof valve 11 and the groove 22 are arranged opposite to each other along the axial direction of the current collector plate 2. At this time, at least part of the orthographic projection of the explosion-proof valve 11 on the current collector plate 2 is located on the groove 22. When the energy storage device 100 is impacted due to reasons such as impact and drop, if the electrolyte infiltrating the electrode assembly generates a moving impact from the position where the electrode assembly is located to the position where the explosion-proof valve 11 is located, the electrolyte will be blocked by the groove 22. The groove 22 bears part of the impact caused by the electrolyte, plays a buffering role for the explosion-proof valve 11, reduces the impact pressure on the explosion-proof valve 11 from the electrolyte, prevents the explosion-proof valve 11 from being accidentally triggered and broken under the impact of the electrolyte, is beneficial to improving the safety performance of the energy storage device 100, and prolongs the service life of the energy storage device 100.

[0105] Among them, the surface recognition features of different regions can be recognized or measured by a contact detection device, or the surface recognition features can be recognized or measured by a non-contact detection device, or can also be recognized manually. Exemplarily, the contact detection device can be an instrument that detects according to the principle of needle tracing method, and a stylus is used to gently slide directly on the measured surface for recognition or measurement; the non-contact detection device uses principles such as interference method and optical section method for detection and does not need to contact the measured surface; it can also be recognized manually by using the vision and touch of the human body.

[0106] Exemplarily, the driving device is in transmission connection with the end cover 1 and the identification device. The driving device drives the end cover 1 to rotate around its central axis to adjust the position of the explosion-proof valve 11 relative to the current collector plate 2. It can be understood that the detection device moves synchronously with the end cover 1 so that the detection device always identifies or measures the current collector plate 2 through the liquid injection hole 12.

[0107] The method for installing and positioning the end cover assembly provided in this application adjusts the position of the explosion-proof valve 11 relative to the current collector plate 2 according to the surface recognition feature of the surface recognition part 25, which is convenient for accurately aligning the current collector plate 2 and the end cover 1 during the production and manufacturing process of the energy storage device 100, so that the explosion-proof valve 11 and the groove 22 are arranged opposite to each other along the axial direction of the current collector plate 2, and at least part of the orthographic projection of the explosion-proof valve 11 on the current collector plate 2 is located in the groove 22; when the energy storage device 100 is subjected to impact, collision or drop, the electrolyte inside the housing of the energy storage device 100 will impact towards the side where the current collector plate 2 and the end cover 1 are located. After being blocked and counterattacked by the groove 22, the flow direction of the electrolyte deflects, making it difficult for the electrolyte to directly impact the explosion-proof valve 11, reducing the pressure on the explosion-proof valve 11, and reducing the probability of the explosion-proof valve 11 being accidentally triggered due to the impact of the electrolyte, which is beneficial to improving the safety performance of the energy storage device 100 and prolonging the service life of the energy storage device 100.

[0108] In a further embodiment, the deflection angle of the groove 22 relative to the surface recognition part 25 is the same as the deflection angle of the explosion-proof valve 11 relative to the liquid injection hole 12. The determination in step S10 that the explosion-proof valve 11 and the groove 22 are arranged opposite to each other along the axial direction of the current collector plate 2 specifically includes:

[0109] Determine that the liquid injection hole 12 is aligned with the surface recognition part 25.

[0110] Since the deflection angle of the groove 22 relative to the surface recognition part 25 is the same as the deflection angle of the explosion-proof valve 11 relative to the liquid injection hole 12, during the process of aligning the end cover assembly through the liquid injection hole 12, it is only necessary to align the liquid injection hole 12 with the surface recognition part 25 so that the liquid injection hole 12 and the surface recognition part 25 are arranged opposite to each other along the axial direction of the current collector plate 2, then the positions of the explosion-proof valve 11 and the groove 22 can be aligned, making the explosion-proof valve 11 and the groove 22 arranged opposite to each other along the axial direction of the current collector plate 2, reducing the installation and positioning difficulty of the end cover assembly, and being beneficial to quickly completing the alignment of the end cover 1 and the current collector plate 2.

[0111] Further, the surface recognition feature includes at least one of roughness, texture, and waviness. The determination that the liquid injection hole 12 is aligned with the surface recognition part 25 specifically includes:

[0112] Determine that the surface recognition feature of the area where the liquid injection hole 12 is aligned is the surface recognition feature of the surface recognition part 25.

[0113] Since the surface recognition features of the surface recognition part 25 are different from those of the area other than the surface recognition part 25 on the upper surface of the main body part 21, when using a detection device to recognize or measure each area of the main body part 21, the surface recognition part 25 can be distinguished from the area other than the surface recognition part 25 on the upper surface of the main body part 21, and the position of the explosion-proof valve 11 relative to the current collector can be adjusted based on the position of the surface recognition part 25 to ensure that the explosion-proof valve 11 and the groove 22 are arranged opposite to each other along the axial direction of the current collector plate 2, and at least part of the orthographic projection of the explosion-proof valve 11 on the current collector plate 2 is located in the groove 22.

[0114] Furthermore, the roughness of the surface recognition part 25 is greater than or equal to a preset roughness, and the roughness of the area other than the surface recognition part 25 on the upper surface of the main body part 21 is less than the preset roughness. Determining that the surface recognition feature of the area aligned with the liquid injection hole 12 is the surface recognition feature of the surface recognition part 25 includes:

[0115] Determining that the roughness of the area aligned with the liquid injection hole 12 is greater than the preset roughness.

[0116] In this embodiment, the roughness of the surface recognition part 25 is different from that of the area other than the surface recognition part 25 on the upper surface of the main body part 21, and the roughness of the surface recognition part 25 is greater than that of the area other than the surface recognition part 25 on the upper surface of the main body part 21. By using a measuring device to recognize the area with a larger roughness and determining this area as the surface recognition part 25, and adjusting the air vent to be arranged opposite to the surface recognition part 25 along the axial direction of the current collector plate 2, it can be ensured that the explosion-proof valve 11 and the groove 22 are arranged opposite to each other along the axial direction of the current collector plate 2, reducing the probability that the explosion-proof valve 11 is accidentally triggered by the impact of the electrolyte.

[0117] Wherein, the preset roughness is a parameter set in advance. The area with a roughness greater than or equal to the preset roughness is the area where the surface recognition part 25 is located, and the area with a roughness less than the preset roughness is the area other than the surface recognition part 25 on the upper surface of the main body part 21. Based on the preset roughness, by numerically comparing the detected roughness with the preset roughness, the area where the surface recognition part 25 is located can be quickly determined, improving the alignment efficiency of the end cap 1 and the current collector plate 2.

[0118] In the description of this specification, the descriptions with reference to terms such as "embodiment", "specific embodiment", "example" or "specific example" mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0119] The above disclosure is only a preferred embodiment of the present application. Of course, it cannot be used to limit the scope of the rights of the present application. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present application still fall within the scope covered by the present application.

Claims

1. An end cap assembly, characterized in that, Comprising: An end cap (1) having an explosion-proof valve (11) and a liquid injection hole (12), the liquid injection hole (12) and the explosion-proof valve (11) being spaced apart; A current collector plate (2) coaxially arranged with the end cap (1), the current collector plate (2) including a main body portion (21), a groove (22) being formed on the surface of the main body portion (21) facing the end cap (1), the groove (22) extending from the center of the main body portion (21) towards the edge of the main body portion (21), a surface identification portion (25) being provided on the main body portion (21), the surface identification portion (25) having a surface identification feature different from the area other than the surface identification portion (25) on the main body portion (21), the surface identification feature being used to characterize the surface undulation degree, and the surface identification feature being at least recognizable or measurable by a contact detection device; An installation hole (13) is formed at the central axis position of the end cap (1), and a boss (24) is provided at the central axis position of the current collector plate (2), the boss (24) being rotatably inserted into the installation hole (13) during the manufacturing process; Wherein, the liquid injection hole (12) is used to align the end cap (1) and the current collector plate (2) through the surface identification portion (25), so that the explosion-proof valve (11) and the groove (22) are axially opposite to each other along the current collector plate (2), and the overlapping area of the orthographic projection of the explosion-proof valve (11) on the current collector plate (2) and the groove (22) is greater than or equal to 30% of the orthographic projection area of the explosion-proof valve (11).

2. The end cap assembly according to claim 1, wherein The surface identification feature of the surface identification portion (25) includes at least one of roughness, texture, and waviness.

3. The end cap assembly according to claim 2, wherein The roughness of the surface identification portion (25) is greater than the roughness of the area other than the surface identification portion (25) on the main body portion (21), and the ratio of the roughness of the surface identification portion (25) to the roughness of the area other than the surface identification portion (25) on the main body portion (21) is 1.9 - 3.

5.

4. The end cap assembly according to claim 3, characterized in that, The liquid injection hole (12) is located between the central axes of the explosion-proof valve (11) and the main body portion (21), and the surface identification portion (25) is located on the bottom wall of the groove (22).

5. The end cap assembly according to any one of claims 1 to 3, characterized in that, The deflection angle of the groove (22) relative to the surface identification portion (25) is the same as the deflection angle of the explosion-proof valve (11) relative to the liquid injection hole (12); When the liquid injection hole (12) and the surface identification portion (25) are axially opposite to each other along the current collector plate (2), the explosion-proof valve (11) and the groove (22) are axially opposite to each other along the current collector plate (2), and the overlapping area of the orthographic projection of the explosion-proof valve (11) on the current collector plate (2) and the groove (22) is greater than 30% of the orthographic projection area of the explosion-proof valve (11).

6. The end cap assembly according to any one of claims 1 to 3, characterized in that, The number of the surface identification portions (25) and the grooves (22) is multiple, and the multiple surface identification portions (25) and the multiple grooves (22) are alternately distributed one by one on the main body portion (21).

7. The end cap assembly according to claim 6, wherein, The surface identification features of at least two of the surface identification portions (25) are different.

8. The end cap assembly according to claim 6, characterized in that, The liquid injection hole (12) and the explosion-proof valve (11) are distributed radially along the end cover (1), the liquid injection hole (12) and the explosion-proof valve (11) are respectively located on both sides of the central axis of the main body part (21), and any one of the grooves (22) is arranged opposite to one of the surface identification parts (25) radially along the current collecting disc (2).

9. The end cap assembly according to claim 1, characterized in that The shape of the surface identification part (25) is adapted to the shape of the liquid injection hole (12).

10. The end cap assembly according to claim 9, characterized in that, The area of the orthographic projection of the liquid injection hole (12) on the current collecting disc (2) is larger than the area of the surface identification part (25), and the ratio of the area of the orthographic projection of the liquid injection hole (12) on the current collecting disc (2) to the area of the surface identification part (25) is 1.41 to 2.

22.

11. The end cap assembly according to claim 1, characterized in that, The main body part (21) is further provided with a ventilation hole area (23), the ventilation hole area (23) includes a plurality of through holes (231) arranged at intervals, and the surface identification part (25) is located in the ventilation hole area (23).

12. The end cap assembly according to claim 11, characterized in that, The through hole (231) is located on the side of the surface identification part (25) close to the central axis of the current collecting disc (2).

13. The end cap assembly according to claim 1, characterized in that, The overlapping area of the orthographic projection of the explosion-proof valve (11) on the current collecting disc (2) and the groove (22) is larger than 80% of the orthographic projection area of the explosion-proof valve (11).

14. An energy storage device, characterized in that, Comprising the end cover assembly according to any one of claims 1 to 13.

15. A positioning method for an end cap assembly, applied to the end cap assembly according to any one of claims 1 to 13, characterized in that, The method for positioning the end cover assembly includes:[[]] Adjusting the position of the explosion-proof valve relative to the current collecting disc according to the surface identification feature of the surface identification part, and determining that the explosion-proof valve and the groove are arranged axially relative to the current collecting disc.

16. The positioning method of the end cover assembly according to claim 15, characterized in that, The deflection angle of the groove relative to the surface identification part is the same as the deflection angle of the explosion-proof valve relative to the liquid injection hole; The determining that the explosion-proof valve and the groove are arranged axially relative to the current collecting disc specifically includes:[[]] Determining that the liquid injection hole is aligned with the surface identification part.

17. The end cap assembly positioning method according to claim 16, wherein, The surface identification feature includes at least one of roughness, texture, and waviness; The determining that the liquid injection hole is aligned with the surface identification part specifically includes:[[]] Determining that the surface identification feature of the area aligned by the liquid injection hole is the surface identification feature of the surface identification part.

18. The positioning method of the end cover assembly according to claim 17, characterized in that, The roughness of the surface identification part is greater than or equal to a preset roughness, and the roughness of the area other than the surface identification part on the main body part is less than the preset roughness; The determining that the surface identification feature of the area aligned by the liquid injection hole is the surface identification feature of the surface identification part includes:[[]] Determining that the roughness of the area aligned by the liquid injection hole is greater than the preset roughness.

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