Energy storage apparatus, welding method therefor, and electrical device

Abstract

Provided in the present application are an energy storage apparatus, a welding method therefor, and an electrical device. The energy storage apparatus comprises an end cover, a casing and a current collector disc arranged between the end cover and the casing. The current collector disc comprises a body and a welding part, the body and the welding part being an integrated structure. The body comprises a first surface and a second surface that are arranged opposite to each other, the end cover being connected to the first surface of the body, and the casing being connected to the second surface of the body. The welding part is connected to the outer circumferential surfaces of the end cover, the casing and the body. In the energy storage apparatus of the present application, the current collector disc is arranged between the end cover and the casing and is welded to the circumferential surfaces of the end cover and the casing, such that a welding area for the end cover and the current collector disc is enlarged, thereby improving the current flowing capacity between the end cover and the current collector disc and improving the connection strength between the end cover, the current collector disc and the casing.

Description

Energy storage device, welding method, and electrical equipment

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 14, 2023, with application number 2023107024241 and application name “Energy storage device, welding method thereof, and electrical equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the technical field of energy storage devices, and specifically relates to energy storage devices, welding methods, and electrical equipment thereof. Background Art

[0003] A rechargeable battery, also known as a rechargeable battery or storage battery, is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. The recyclable nature of secondary batteries has made them a key power source for electrical devices. As demand for secondary batteries grows, so too have demands for their performance, particularly regarding energy density per unit volume. The gap between the end caps and the wound electrode assembly of cylindrical secondary batteries is a key factor limiting their energy density per unit volume.

[0004] In order to reduce the gap between the positive electrode side end cover and the wound electrode assembly, the existing cylindrical secondary battery has eliminated the traditional connection method of extending a bendable adapter plate from one side of the collector plate and welding it to the pole on the end cover. Instead, the positive electrode collector plate is directly welded to the positive end cover to further reduce the gap between the positive electrode side end cover and the wound electrode assembly.

[0005] Typically, a boss is provided on the current collecting disc, and the end cap is welded to the boss. However, this connection method still has the following problems: First, the welding area between the current collecting disc and the end cap is only the periphery of the boss and the corresponding part of the end cap, so the actual electrical connection area between the positive electrode current collecting disc and the positive end cap is relatively small, which becomes a bottleneck for the current flow capacity in the current path between the wound electrode assembly and the positive end cap. During normal use, due to the small welding area between the end cap and the current collecting disc, the resistance in this area is relatively high, and it is easy to heat up when the current passes through it, resulting in a low connection strength between the end cap and the current collecting disc.

[0006] Second, during the random drop test of the battery, the negative side of the battery occasionally hits the ground with its face down. Under the action of inertia, the wound electrode assembly inside the battery drives the positive current collector plate to move away from the positive terminal cover. The positive current collector plate is pulled away from the positive terminal cover, causing tiny cracks in the welding area. During subsequent electrical tests or normal use, leakage is likely to occur.

[0007] Summary of the Invention

[0008] In view of this, the present application provides an energy storage device and a welding method thereof, and an electrical device. The collecting plate of the energy storage device is welded to the peripheral side of the end cover and the shell, which can improve the connection strength between the end cover, the collecting plate, and the shell.

[0009] In a first aspect, the present application provides an energy storage device, which includes an end cover, a shell, and a current collecting plate arranged between the end cover and the shell. The current collecting plate includes a main body and a welding portion. The main body and the welding portion are an integral structure. The main body includes a first surface and a second surface arranged opposite to each other. The end cover is connected to the first surface of the main body, the shell is connected to the second surface of the main body, and the welding portion is connected to the end cover, the shell, and the outer peripheral side surface of the main body.

[0010] The energy storage device provided in the present application includes an end cover, a shell, and a current collecting plate. The end cover is welded to one side surface of the current collecting plate, and the shell is welded to the other side surface of the current collecting plate away from the end cover. Specifically, the current collecting plate includes a main body and a welding portion, and the main body and the welding portion are an integrated structure. The main body can be understood as the portion of the current collecting plate that does not change before and after welding. The welding portion can be understood as the portion of the current collecting plate that is welded to connect the end cover and the shell after the current collecting plate has been welded, that is, the welding portion is the weld mark left after the molten metal cools and solidifies again after welding.

[0011] First, the end cap in this application is connected to the first surface of the body, the shell is connected to the second surface of the body, and the weld portion connects the outer peripheral side of the body, the end cap, and the shell. Therefore, the weld portion is connected to the peripheral side of the end cap and the shell. In other words, the weld area between the end cap and the current collecting plate is the weld portion of the current collecting plate surrounding the peripheral side of the end cap, and the corresponding peripheral side portion of the end cap. This increases the weld area between the end cap and the current collecting plate, increases the electrical connection area between the end cap and the current collecting plate, and further improves the current flow capacity between the end cap and the current collecting plate, reduces or even avoids the phenomenon of heat generation when concentrated current passes through, and improves the connection strength between the end cap and the current collecting plate.

[0012] Furthermore, the collecting plate in the present application is welded between the end cap and the shell, and the main body is connected to both the surface of the end cap facing the shell and the surface of the shell facing the end cap, with the welded portion connected to the circumferential side surfaces of the end cap and the shell. Therefore, when the energy storage device falls, the collecting plate tends to move away from the end cap due to inertia. However, since the main body is connected to the shell, that is, the main body abuts the shell, the structural strength of the collecting plate itself can be used to abut against the shell, limiting the movement of the collecting plate away from the end cap, thereby further improving the connection strength between the collecting plate, the shell, and the end cap, or in other words, improving the structural strength between the collecting plate, the shell, and the end cap, and reducing the probability of leakage.

[0013] Therefore, the energy storage device of the present application can increase the welding area between the end cover and the current collecting plate, improve the flow capacity between the end cover and the current collecting plate, and improve the connection strength between the end cover and the current collecting plate and the shell by arranging the current collecting plate between the end cover and the shell and welding it to the peripheral side surfaces of the end cover and the shell.

[0014] A second aspect of the present application provides an electrical device, the electrical device comprising:

[0015] the device itself; and

[0016] As for the energy storage device provided in the first aspect of the present application, the energy storage device supplies power to the device body.

[0017] The electrical equipment provided in the second aspect of this application utilizes the energy storage device provided in the first aspect of this application. By positioning a current collecting plate between the end cap and the housing and welding it to the lateral surfaces of the end cap and the housing, the electrical equipment can increase the welding area between the end cap and the current collecting plate, thereby improving the flow capacity between the end cap and the current collecting plate and the connection strength between the end cap, the current collecting plate, and the housing. When the energy storage device is powering the device, it can provide a stable power source for the device.

[0018] A third aspect of the present application provides a welding method for an energy storage device, the welding method comprising:

[0019] Provide end caps, housings, and collecting plates;

[0020] The end cover is abutted against one side surface of the collecting plate, and the shell is abutted against the surface of the collecting plate facing away from the end cover, and the outer peripheral side surface of the collecting plate is exposed;

[0021] Circumferential laser welding is performed on the outer peripheral side of the collecting disc so that the collecting disc is fixedly connected to the end cover and the shell. The collecting disc that has undergone the welding process includes a main body and a welding portion. The main body and the welding portion are an integral structure. The main body includes a first surface and a second surface arranged opposite to each other. The end cover is connected to the first surface of the main body, and the shell is connected to the second surface of the main body. The welding portion is connected to the end cover, the shell, and the outer peripheral side surface of the main body.

[0022] The third aspect of the present application provides a welding method for an energy storage device, which features simple processes and strong operability. By positioning a current collecting plate between the end cap and the housing and using a one-time welding tool to weld the current collecting plate to the circumferential side surfaces of the end cap and the housing, a side-sealed weld is achieved. This increases the welding area between the end cap and the current collecting plate, improves the flow capacity between the end cap and the current collecting plate, and enhances the connection strength between the end cap, the current collecting plate, and the housing.

[0023] Wherein, in the step of exposing the outer peripheral side surface of the collecting plate, a width L3 of the collecting plate protruding from the end cover and the shell satisfies the following range: 0.25 mm ≤ L3 ≤ 2 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0025] FIG1 is a schematic structural diagram of an energy storage device according to an embodiment of the present application.

[0026] FIG2 is an exploded view of the structure of an energy storage device according to an embodiment of the present application.

[0027] FIG3 is a first cross-sectional view of the embodiment of FIG1 of the present application along the AA direction in the figure.

[0028] FIG4 is a partial enlarged view of FIG3 of the present application.

[0029] FIG5 is a second partially enlarged view of FIG3 of the present application.

[0030] FIG6 is a third partially enlarged view of FIG3 of the present application.

[0031] FIG7 is a partial enlarged view of FIG3 of the present application.

[0032] FIG8 is a partially enlarged view 5 of FIG3 of the present application.

[0033] FIG9 is a sixth partial enlarged view of FIG3 of the present application.

[0034] FIG10 is a partial enlarged view of FIG3 of the present application.

[0035] FIG11 is a partial enlarged view 8 of FIG3 of the present application.

[0036] FIG12 is a partial enlarged view 9 of FIG3 of the present application.

[0037] FIG13 is a cross-sectional view of the collecting plate, the end cover, and the shell in the embodiment of FIG1 of the present application, taken along the AA direction, before welding.

[0038] FIG14 is a schematic structural diagram of a current collecting plate according to an embodiment of the present application.

[0039] FIG15 is a schematic structural diagram of the current collecting plate in FIG14 of the present application from another perspective.

[0040] FIG16 is a schematic structural diagram of an end cover according to an embodiment of the present application.

[0041] FIG17 is a schematic structural diagram of the end cover in FIG16 of the present application from another perspective.

[0042] FIG18 is a second cross-sectional view of the embodiment of FIG1 of the present application along the AA direction in the figure.

[0043] FIG19 is a schematic structural diagram of a current collecting plate according to another embodiment of the present application.

[0044] FIG20 is a schematic structural diagram of the current collecting plate in FIG19 of the present application from another perspective.

[0045] FIG21 is a cross-sectional view of the embodiment of FIG19 of the present application along the BB direction in the figure.

[0046] FIG22 is a partially enlarged view of FIG18 of the present application.

[0047] FIG23 is a schematic structural diagram of an electrical device according to an embodiment of the present application.

[0048] FIG24 is a process flow chart of a welding method for an energy storage device in one embodiment of the present application.

[0049] FIG25 is a process flow chart of a welding method for an energy storage device in another embodiment of the present application.

[0050] Description of labels:

[0051] Energy storage device-1, end cover-11, explosion-proof valve-111, second liquid injection hole-112, first part-113, second part-114, cavity-115, shell-12, accommodating chamber-121, collecting plate-13, body-131, first surface-131a, second surface-131b, welding part-132, first liquid injection hole-133, first positioning part-134, first top surface-1341, first side surface-1342, positioning protrusion-1343, positioning protrusion ring-1344, first through hole-135, limiting protrusion-136, second top surface-1361, second side surface-1362, second through hole-137, second positioning part-138, electrode assembly-14, hollow structure-141, electrical equipment-2, equipment body-21. DETAILED DESCRIPTION

[0052] The following are preferred implementations of the present application. It should be noted that ordinary technicians in this technical field can make several improvements and modifications without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

[0053] Please refer to Figures 1 to 9. Figure 1 is a schematic structural diagram of an energy storage device according to an embodiment of the present application. Figure 2 is an exploded structural diagram of an energy storage device according to an embodiment of the present application. Figure 3 is a cross-sectional view of the embodiment of Figure 1 of the present application along the AA direction in the figure. Figure 4 is a partially enlarged view of Figure 3 of the present application. Figure 5 is a partially enlarged view of Figure 3 of the present application. Figure 6 is a partially enlarged view of Figure 3 of the present application. Figure 7 is a partially enlarged view of Figure 3 of the present application. Figure 8 is a partially enlarged view of Figure 3 of the present application. Figure 9 is a partially enlarged view of Figure 3 of the present application.

[0054] The present application provides an energy storage device 1, wherein a current collecting plate 13 of the energy storage device 1 is welded to the peripheral side surfaces of an end cap 11 and a housing 12, thereby improving the connection strength between the end cap 11, the current collecting plate 13, and the housing 12. Optionally, the energy storage device 1 may be, but is not limited to, a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery.

[0055] The energy storage device 1 provided in this embodiment includes an end cover 11, a shell 12, and a current collecting plate 13 arranged between the end cover 11 and the shell 12. The current collecting plate 13 includes a body 131 and a welding portion 132. The body 131 and the welding portion 132 are an integral structure. The body 131 includes a first surface 131a and a second surface 131b arranged opposite to each other. The end cover 11 is connected to the first surface 131a of the body 131, the shell 12 is connected to the second surface 131b of the body 131, and the welding portion 132 is connected to the outer peripheral side surfaces of the end cover 11, the shell 12, and the body 131.

[0056] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application and the above drawings are used to distinguish different objects rather than to describe a specific order.

[0057] The energy storage device 1 provided in this embodiment includes an end cap 11 for electrically connecting to a current collecting plate 13 and securing and protecting other components. End cap 11 is connected to current collecting plate 13. For example, a portion of end cap 11 is welded to current collecting plate 13. In another example, a portion of end cap 11 abuts current collecting plate 13. Optionally, the shape of end cap 11 may be, but is not limited to, circular, rectangular, or bottle cap-shaped. Optionally, end cap 11 is a positive terminal cap 11 or a negative terminal cap 11.

[0058] Optionally, end cap 11 is provided with an explosion-proof valve 111 for discharging gases generated within energy storage device 1 to prevent explosions and improve the safety of energy storage device 1. Optionally, end cap 11 has a second injection port 112 for injecting electrolyte. Further, optionally, second injection port 112 is located in the center of end cap 11.

[0059] The energy storage device 1 provided in this embodiment also includes a shell 12 for accommodating, fixing and protecting other components. The shell 12 is connected to the collecting plate 13. For example, part of the shell 12 is welded to the collecting plate 13. For another example, part of the shell 12 abuts the collecting plate 13. Optionally, the shell 12 is made of a metal material such as aluminum, copper, or an alloy. Optionally, the shape of the shell 12 can be, but is not limited to, circular, rectangular, etc. Optionally, the shell 12 is adapted to the shape of the end cover 11. In other words, the shell 12 has the same shape as the end cover 11. Optionally, the energy storage device 1 also includes an electrode assembly 14, and the shell 12 has a accommodating cavity 121, and the electrode assembly 14 is arranged in the accommodating cavity 121.

[0060] The energy storage device 1 provided in this embodiment also includes a current collecting disc 13, which is used to electrically connect the end cover 11, the shell 12, and the electrode assembly 14. The end cover 11 is welded to one side surface of the current collecting disc 13, and the shell 12 is welded to the other side surface of the current collecting disc 13 away from the end cover 11. Among them, the current collecting disc 13 includes a main body 131 and a welding portion 132, and the main body 131 and the welding portion 132 are an integral structure. The main body 131 can be understood as the part of the current collecting disc 13 that does not change before and after welding. The welding portion 132 can be understood as the part of the current collecting disc 13 that is welded to connect the end cover 11 and the shell 12 after the current collecting disc 13 is welded, that is, the welding portion 132 is the weld mark after the molten metal is cooled and solidified again after welding. Optionally, the outer side surfaces of the main body 131 and the welding portion 132 can be flat or curved, and this application does not limit this.

[0061] It should be noted that, to more clearly illustrate the main body 131 and the welding portion 132, the main body 131 and the welding portion 132 are labeled with different graphics in Figures 7-9. However, in actual production, the main body 131 and the welding portion 132 are an integral structure, as shown in Figures 4-6. As shown in Figures 7-9, the first surface 131a of the main body 131 is connected to the end cap 11. At least a portion of the end cap 11 abuts the first surface 131a of the main body 131. For example, the side surface of the end cap 11 facing the collecting plate 13 abuts the first surface 131a. For another example, due to some solder flowing between the main body 131 and the end cap 11, a portion of the side surface of the end cap 11 facing the collecting plate 13 abuts the first surface 131a, while another portion of the side surface of the end cap 11 facing the collecting plate 13 abuts the welding portion 132. At least a portion of the housing 12 abuts the second surface 131b of the main body 131. For example, the side surface of the housing 12 facing the collecting tray 13 abuts the second surface 131 b. For another example, because some solder flows between the body 131 and the housing 12, a portion of the side surface of the housing 12 facing the collecting tray 13 abuts the second surface 131 b, while another portion of the side surface of the housing 12 facing the collecting tray 13 abuts the welding portion 132.

[0062] Welding portion 132 is connected to the outer peripheral side of body 131, which is connected between first surface 131a and second surface 131b. Welding portion 132 also connects end cap 11 and housing 12. For example, welding portion 132 is connected to the outer peripheral side of housing 12. For another example, welding portion 132 is connected to the outer peripheral side of end cap 11. For another example, welding portion 132 is connected to the side of housing 12 facing current collecting plate 13. For another example, welding portion 132 is connected to the side of end cap 11 facing current collecting plate 13.

[0063] It can be understood that since the welding portion 132 is the part of the collecting plate 13 that is welded to connect the end cover 11 and the shell 12 after the collecting plate 13 is welded, there are many situations in which the welding portion 132 is connected to the end cover 11 and the shell 12. The above-mentioned connection relationship between the welding portion 132 and the end cover 11 and the shell 12 can exist alone or in multiple combinations.

[0064] It will be appreciated that the collecting tray 13 in this embodiment does not have a boss structure facing the end cap 11. This boss structure is similar to the boss structure used for welding to the end cap 11 in related art. Optionally, the collecting tray 13 has a first injection hole 133 for injecting electrolyte. Furthermore, optionally, the first injection hole 133 is located in the center of the collecting tray 13. Furthermore, optionally, the first injection hole 133 is located opposite the second injection hole 112.

[0065] Optionally, the shape of the current collecting disc 13 can be, but is not limited to, circular, rectangular, or the like. Optionally, the shapes of the current collecting disc 13, the housing 12, and the end cap 11 are compatible. In other words, the shapes of the current collecting disc 13, the housing 12, and the end cap 11 are identical. Optionally, the current collecting disc 13 is a positive electrode current collecting disc 13 or a negative electrode current collecting disc 13. For example, when the end cap 11 is a positive electrode end cap 11, the current collecting disc 13 is a positive electrode current collecting disc 13; when the end cap 11 is a negative electrode end cap 11, the current collecting disc 13 is a negative electrode current collecting disc 13.

[0066] First, in this embodiment, the end cap 11 is connected to the first surface 131a of the body 131, and the housing 12 is connected to the second surface 131b of the body 131. The weld 132 connects the outer peripheral side of the body 131, the end cap 11, and the housing 12. Therefore, the weld 132 is connected to the peripheral side of the end cap 11 and the housing 12. In other words, the weld area between the end cap 11 and the current collecting plate 13 is the weld 132 surrounding the peripheral side of the current collecting plate 13 and the corresponding peripheral portion of the end cap 11. This can also be understood as expanding the electrical connection area between the end cap 11 and the current collecting plate 13 to the outer diameter of the end cap 11. This increases the weld area between the end cap 11 and the current collecting plate 13, thereby increasing the electrical connection area between the end cap 11 and the current collecting plate 13. This improves the current carrying capacity between the end cap 11 and the current collecting plate 13, reduces or even prevents the occurrence of heat generation when concentrated current passes through the end cap 11, and enhances the connection strength between the end cap 11 and the current collecting plate 13. The flow capacity between the end cover 11 and the current collecting plate 13 refers to the flow capacity of the current path between the end cover 11 and the current collecting plate 13 .

[0067] It should be noted that the housing 12 has two radial dimensions: one dimension (i.e., outer diameter) of the outer peripheral sidewall of the housing 12, and the other dimension (i.e., inner diameter) of the inner peripheral sidewall of the housing 12. The outer diameter and inner diameter mentioned below in this application should be understood in the same way and will not be further elaborated in this application.

[0068] Furthermore, the collecting tray 13 in this embodiment is welded between the end cap 11 and the housing 12. The body 131 is connected to both the surface of the end cap 11 facing the housing 12 and the surface of the housing 12 facing the end cap 11. The weld 132 is connected to the circumferential side surfaces of the end cap 11 and the housing 12. Therefore, when the energy storage device 1 falls, the collecting tray 13 tends to move away from the end cap 11 due to inertia. However, because the body 131 is connected to the housing 12, that is, the body 131 abuts the housing 12, the structural strength of the collecting tray 13 itself can be used to abut against the housing 12, limiting the movement of the collecting tray 13 away from the end cap 11. This further improves the connection strength between the collecting tray 13 and the housing 12 and the end cap 11, or in other words, improves the structural strength between the collecting tray 13 and the housing 12 and the end cap 11, thereby reducing the probability of leakage.

[0069] For example, in a random drop test of a battery, the negative side of the battery hits the ground with its negative pole facing downward. Under the action of inertia, the wound electrode assembly 14 inside the battery drives the positive current collecting disc 13 to move away from the positive end cover 11. Since the positive current collecting disc 13 abuts against the shell 12, it can use its own structural strength to abut against the shell 12, limiting its continued movement toward the ground and further improving the structural strength of the welding area between the current collecting disc 13 and the shell 12 and the end cover 11.

[0070] Therefore, the energy storage device 1 of this embodiment can increase the welding area between the end cover 11 and the current collecting plate 13 by arranging the current collecting plate 13 between the end cover 11 and the shell 12 and welding it to the peripheral side surfaces of the end cover 11 and the shell 12, thereby improving the flow capacity between the end cover 11 and the current collecting plate 13 and improving the connection strength between the end cover 11 and the current collecting plate 13 and the shell 12.

[0071] Please refer to Figures 1 to 13 together. Figure 10 is a partial enlarged Figure 7 of Figure 3 of the present application. Figure 11 is a partial enlarged Figure 8 of Figure 3 of the present application. Figure 12 is a partial enlarged Figure 9 of Figure 3 of the present application. Figure 13 is a cross-sectional view of the collecting plate 13, the end cover 11, and the shell 12 in the welding front in the AA direction of the embodiment of Figure 1 of the present application. It should be noted that in order to more clearly represent the main body 131 and the welding part 132, in Figures 7 to 12, the main body 131 and the welding part 132 are marked with different graphics. However, in actual production, the main body 131 and the welding part 132 are an integrated structure, as shown in Figures 4 to 6.

[0072] In one embodiment, the collecting plate 13 satisfies at least one of the following conditions: along the radial direction of the collecting plate 13 (as shown in direction D in Figure 7), the outer peripheral side surface of the main body 131 is flush with the outer peripheral side surface of the end cover 11 and / or the outer peripheral side surface of the shell 12; and / or, along the radial direction of the collecting plate 13 (as shown in direction D in Figure 10), the outer peripheral side surface of the main body 131 protrudes from the outer peripheral side surface of the end cover 11 and / or the outer peripheral side surface of the shell 12.

[0073] For example, in the radial direction of the collecting disc 13, at least a portion of the outer circumferential side surface of the body 131 is flush with the outer circumferential side surface of the end cover 11. For another example, in the radial direction of the collecting disc 13, at least a portion of the outer circumferential side surface of the body 131 is flush with the outer circumferential side surface of the housing 12. For another example, in the radial direction of the collecting disc 13, at least a portion of the outer circumferential side surface of the body 131 protrudes from the outer circumferential side surface of the end cover 11. For another example, in the radial direction of the collecting disc 13, at least a portion of the outer circumferential side surface of the body 131 protrudes from the outer circumferential side surface of the housing 12.

[0074] In this embodiment, the body 131 is flush with the end cap 11 and / or the housing 12, or even protrudes from the end cap 11 and / or the housing 12. In other words, the radial dimension of the body 131 is equal to or greater than the radial dimension of the outer circumference of the end cap 11; and / or, the radial dimension of the body 131 is equal to or greater than the radial dimension of the outer circumference of the housing 12. Furthermore, in the radial direction of the collecting plate 13, the weld 132 is connected to the outer circumference of the body 131. Therefore, the radial dimension of the collecting plate 13 is greater than the radial dimension of the outer circumference of the end cap 11 and the radial dimension of the outer circumference of the housing 12. In other words, the diameter of the collecting plate 13 is slightly larger than the diameter of the end cap 11 and the diameter of the housing 12.

[0075] Therefore, during the welding process, the assembled end cap 11, current collecting plate 13 and shell 12 can be placed horizontally and welded together at the side wall of the energy storage device 1 in one step. Specifically, before welding the current collecting plate 13, end cap 11, and shell 12, the current collecting plate 13 can be arranged to protrude from the end cap 11 and shell 12. It can also be understood that the current collecting plate 13 has a circle of welding protrusions protruding from the outer wall of the end cap 11 and the outer wall of the shell 12 for welding, so that the laser welding head can be directly aimed at the welding protrusions for heating, and the shell 12 rotates at a constant speed to form a single weld. At this time, the welding protrusions are first heated and melted to form a "melted top", that is, after the welding protrusions melt, they flow to both sides under the action of gravity, filling the gap between the end cap 11 and the current collecting plate 13, or the gap between the shell 12 and the current collecting plate 13, and are welded together with the subsequently melted end cap 11 and shell 12, further improving the structural strength and airtightness of the welding area. It can also be understood that the welding protrusions can melt to form solder. In addition, due to the “melting top” effect of the welding convex ring, the processing accuracy requirements of the joint surface between the end cover 11 and the shell 12 are reduced, thereby reducing the processing cost of the components of the energy storage device 1.

[0076] Optionally, as shown in Figure 13, before welding the collecting plate 13, end cap 11, and housing 12, the width L3 of the collecting plate 13 protruding from the end cap 11 and the housing 12 satisfies the following range: 0.25 mm ≤ L3 ≤ 2 mm. Alternatively, the width L3 of the welded protruding ring protruding from the end cap 11 and the housing 12 satisfies the following range: 0.25 mm ≤ L3 ≤ 2 mm. The width L3 refers to the distance from the outer sidewall of the collecting plate 13 to the outer sidewall of the end cap 11, or from the outer sidewall of the collecting plate 13 to the outer sidewall of the housing 12. Specifically, the value of the width L3 can be but is not limited to 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, and 2mm, etc.

[0077] In this embodiment, when the width L3 satisfies the range of 0.25mm≤L3≤2mm, not only can the machining accuracy requirements of the joint surface between the end cap 11 and the shell 12 be reduced, and the structural strength and airtightness of the weld area be improved, but the welding process time can also be reduced, welding efficiency can be improved, and production costs can be reduced. If the size of L3 is too small, it will be detrimental to the alignment of the laser welding head, the increase in the machining accuracy requirements of the joint surface between the end cap 11 and the shell 12, and it will be detrimental to the welding convex ring after melting to weld the end cap 11 and the shell 12, reducing the structural strength and airtightness of the weld area. If the size of L3 is too large, the welding process time will be increased, welding efficiency will be reduced, and production costs will also be increased.

[0078] Referring to Figure 7 , in one embodiment, the width L1 of the weld portion 132 protruding from the end cap 11 satisfies the following range: 0.05mm≤L1≤1.45mm; and / or the width L2 of the weld portion 132 protruding from the housing 12 satisfies the following range: 0.05mm≤L2≤1.45mm. The width L1 refers to the distance from the outer peripheral sidewall of the weld portion 132 to the outer peripheral sidewall of the end cap 11, or in other words, the height of the weld portion 132 protruding from the outer peripheral sidewall of the end cap 11. The width L2 refers to the distance from the outer peripheral sidewall of the weld portion 132 to the outer peripheral sidewall of the housing 12, or in other words, the height of the weld portion 132 protruding from the outer peripheral sidewall of the housing 12. Specifically, the values ​​of the widths L1 and L2 may be, but are not limited to, 0.05mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, and 1.45mm, etc.

[0079] In this embodiment, when width L1 satisfies the range of 0.05mm≤L1≤1.45mm, and when L1 is greater than or equal to 0.05mm, the height of weld portion 132 protruding from the sidewall surface of end cap 11 is greater than or equal to 0.05mm. This ensures that the molten weld portion 132 during welding can fully fill the slight gap between current collecting plate 13 and end cap 11, while also allowing a redundant portion to protrude from the sidewall surface of end cap 11, thereby improving the sealing performance and structural strength of the weld. When L1 is less than or equal to 1.45mm, the weld mark after welding does not protrude excessively from the sidewall surface of end cap 11, making the subsequent plastic-encapsulated insulating film less likely to wrinkle. When the energy storage device 1 is assembled into the module, it is less likely to interfere with the module's receiving groove, preventing smooth placement.

[0080] In this embodiment, when width L2 satisfies the range of 0.05mm≤L2≤1.45mm, and when L2 is greater than or equal to 0.05mm, the height of weld portion 132 protruding from the sidewall surface of housing 12 is greater than or equal to 0.05mm. This ensures that the molten weld portion 132 during welding can fully fill the slight gap between collecting plate 13 and housing 12, while also allowing a redundant portion to protrude from the sidewall surface of housing 12, thereby improving the sealing performance and structural strength of the weld. When L2 is less than or equal to 1.45mm, the weld mark after welding does not protrude excessively from the sidewall surface of housing 12, making the subsequent plastic insulation film less likely to wrinkle. When energy storage device 1 is assembled into a module, it is less likely to interfere with the module's receiving groove, preventing smooth placement.

[0081] Please refer to Figures 1 to 13 together. In one embodiment, the outer peripheral side surface of the end cover 11 is flush with the outer peripheral side surface of the shell 12.

[0082] In this embodiment, the outer circumferential side surface of the end cap 11 is flush with the outer circumferential side surface of the housing 12. In other words, the radial dimension of the outer circumferential side wall of the end cap 11 is equal to the radial dimension of the outer circumferential side wall of the housing 12, or in other words, the outer diameter of the end cap 11 is equal to the outer diameter of the housing 12. This arrangement facilitates that when the collecting plate 13 is welded to the end cap 11 and the housing 12, the welded portion 132 connecting the end cap 11 and the housing 12 is substantially the same. In other words, the area of ​​the welding region between the collecting plate 13 and the end cap 11 is similar to, or even equal to, the area of ​​the welding region between the collecting plate 13 and the housing 12.

[0083] Therefore, the radial dimension of the outer peripheral side wall of the end cover 11 is equal to the radial dimension of the outer peripheral side wall of the shell 12, which can reduce the difficulty of assembly and improve the stability of assembly; at the same time, such a setting can also improve the energy density per unit volume of the energy storage device 1.

[0084] Please refer to Figures 14 to 21. Figure 14 is a schematic structural diagram of the current collecting disk of an embodiment of the present application. Figure 15 is a schematic structural diagram of the current collecting disk in Figure 14 of the present application from another perspective. Figure 16 is a schematic structural diagram of the end cover of an embodiment of the present application. Figure 17 is a schematic structural diagram of the end cover in Figure 16 of the present application from another perspective. Figure 18 is a second cross-sectional view of the embodiment of Figure 1 of the present application along the AA direction in the figure. Figure 19 is a schematic structural diagram of the current collecting disk of another embodiment of the present application. Figure 20 is a schematic structural diagram of the current collecting disk in Figure 19 of the present application from another perspective. Figure 21 is a cross-sectional view of the embodiment of Figure 19 of the present application along the BB direction in the figure.

[0085] In one embodiment, a first positioning portion 134 is protruding from the first surface 131a of the main body 131, and the outer peripheral side surface of the first positioning portion 134 is spaced apart from the outer peripheral side surface of the main body 131. The end cover 11 includes a first part 113 and a second part 114 bent and connected to the periphery of the first part 113. The surface of the second part 114 close to the main body 131 is connected to the first surface 131a, and the inner peripheral side surface of the second part 114 abuts against the outer peripheral side surface of the first positioning portion 134.

[0086] The end cap 11 provided in this embodiment includes a first portion 113 and a second portion 114 connected by a bend. The first portion 113 is positioned further away from the collecting tray 13 than the second portion 113. The first portion 113 and the second portion 114 are arranged at an angle. The side of the second portion 114 facing away from the first portion 113 is connected to the first surface 131a. A gap exists between the surface of the first portion 113 facing the collecting tray 13 and the first surface 131a. The shape of the end cap 11 can also be understood as that of a bottle cap.

[0087] The main body 131 provided in this embodiment is provided with a first positioning portion 134 to facilitate the assembly of the end cover 11 on the collecting plate 13 for positioning. There is a gap between the outer peripheral side of the first positioning portion 134 and the outer peripheral side of the main body 131, so that the second part 114 of the end cover 11 is connected to the first surface 131a. Among them, the inner peripheral side of the second part 114 abuts the outer peripheral side of the first positioning portion 134. For example, part of the inner peripheral side of the second part 114 abuts the outer peripheral side of the first positioning portion 134. For another example, part of the inner peripheral side of the second part 114 abuts part of the outer peripheral side of the first positioning portion 134. It can also be understood that the end cover 11 includes a second part 114 extending from the first part 113 toward the collecting plate 13, and the second part 114 is covered on the first positioning portion 134. Optionally, the surface of the first positioning portion 134 facing away from the body 131 is spaced apart from the surface of the first portion 113 facing the body 131; alternatively, the surface of the first positioning portion 134 facing away from the body 131 abuts the surface of the first portion 113 facing the body 131. Optionally, the first positioning portion 134 is formed by stamping the body 131. The first positioning portion 134 is formed on the first surface 131a by stamping the second surface 131b of the body 131 in a direction from the second surface 131b to the first surface 131a.

[0088] This embodiment provides a first positioning portion 134 on the first surface 131a of the body 131, with the outer side surface of the first positioning portion 134 abutting the outer side surface of the second portion 114 of the end cap 11. This facilitates positioning of the end cap 11 when mounted on the collecting tray 13. This not only reduces assembly difficulty and improves the accuracy of mounting the end cap 11 on the collecting tray 13, but also reduces tooling requirements for a single weld. Furthermore, the outer sidewall of the first positioning portion 134 abuts the inner sidewall of the second portion 114 of the end cap 11, further increasing the flow area between the end cap 11 and the collecting tray 13, thereby further improving the flow capacity of the end cap 11 and the collecting tray 13.

[0089] Optionally, the first portion 113 of the end cap 11 has a second liquid injection hole 112, which is located at the center of the first portion 113. The body 131 of the collecting tray 13 has a first liquid injection hole 133, which is located at the center of the body 131. In this embodiment, a first positioning portion 134 is provided on the first surface 131a of the body 131 to provide a positioning function. When the end cap 11 is installed on the collecting tray 13, the center of the first portion 113 of the end cap 11 corresponds to the center of the body 131 of the collecting tray 13. In other words, the central axes of the end cap 11 and the collecting tray 13 coincide, or the centers of the end cap 11 and the collecting tray 13 are aligned, thereby aligning the first liquid injection hole 133 with the second liquid injection hole 112. This improves liquid injection efficiency, reduces assembly difficulty, and increases the accuracy of the installation of the end cap 11 on the collecting tray 13.

[0090] Optionally, the first portion 113 of the end cap 11 is provided with an explosion-proof valve 111 for discharging gas generated within the energy storage device 1. The first positioning portion 134 and the first portion 113 enclose a gas collection space for accommodating the gas generated within the energy storage device 1. In this embodiment, by providing the first positioning portion 134 on the first surface 131a of the body 131, a gas collection space is formed below the explosion-proof valve 111 of the end cap 11. This facilitates the accumulation of gas generated within the energy storage device 1. When the gas pressure reaches a preset value, the gas is discharged from the explosion-proof valve 111, preventing explosion and further improving the safety performance of the energy storage device 1. In addition, when the end cover 11 is subjected to gas impact or impact, the first positioning portion 134 can also abut the end cover 11. For example, the outer wall of the first positioning portion 134 abuts the inner wall of the second portion 114, and the top surface of the first positioning portion 134 facing away from the main body 131 abuts the surface of the first portion 113 facing the collecting plate 13, thereby reducing the degree of deformation of the end cover 11 and further improving the structural strength of the energy storage device 1.

[0091] Please refer to Figure 18 and Figure 22 , Figure 22 is a partial enlarged view of Figure 18 of this application. In one embodiment, the end of the first positioning portion 134 facing away from the body 131 is spaced apart from the surface of the first portion 113 facing the body 131 .

[0092] In this embodiment, a gap exists between the end of the first positioning portion 134 facing away from the body 131 and the surface of the first portion 113 facing the body 131. In other words, the first positioning portion 134 is spaced apart from the first portion 113. In this embodiment, by spacing the first positioning portion 134 and the first portion 113 apart, the first positioning portion 134 does not directly abut the first portion 113 of the end cover 11 when the end cover 11 and the collecting plate 13 are assembled, thereby reducing the chance of the first positioning portion 134 damaging the end cover 11. Furthermore, when the end cover 11 is subjected to gas shock or impact, the deformed first portion 113 of the end cover 11 can abut the surface of the first positioning portion 134 facing away from the body 131, thereby reducing the degree of deformation of the end cover 11 and further improving the structural strength of the energy storage device 1.

[0093] Optionally, a distance H (shown as H in FIG. 22 ) between a surface of the first positioning portion 134 facing away from the body 131 and a surface of the first portion 113 facing the body 131 satisfies the following range: 0<H≤0.5 mm. Specifically, the distance H may be, but is not limited to, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, or 0.5 mm.

[0094] In this embodiment, when the spacing H satisfies the range of 0<H≤0.5mm, not only can the probability of the first positioning portion 134 damaging the end cap 11 be reduced, but the first positioning portion 134 can also play a supporting role when the end cap 11 is impacted, thereby reducing the degree of deformation of the end cap 11. If the size of H is too small, the first positioning portion 134 will easily abut the end cap 11 directly, causing the first positioning portion 134 to easily damage the end cap 11. If the size of H is too large, the first positioning portion 134 will be unable to support the end cap 11 when the end cap 11 is impacted, resulting in a greater degree of deformation of the end cap 11, thereby reducing the structural strength of the energy storage device 1.

[0095] Please refer to Figure 14 and Figure 21 together. In one embodiment, the first positioning portion 134 includes a first top surface 1341 facing away from the first surface 131a, and a first side surface 1342 bent and connected to the first top surface 1341. The first side surface 1342 is also connected to the first surface 131a. The connection between the first top surface 1341 and the first side surface 1342 has an arc chamfer.

[0096] In this embodiment, the connection between the first top surface 1341 and the first side surface 1342 has an arc-shaped chamfer. It can also be understood that the connection between the first top surface 1341 and the first side surface 1342 is an arc surface, and the arc surface bulges in the direction away from the first surface 131a, or in other words, the arc surface bulges in the direction of the first part 113 close to the end cover 11.

[0097] Optionally, when the first positioning portion 134 includes a plurality of positioning protrusions 1343 spaced apart, the connection between the first top surface 1341 and the first side surface 1342 of each positioning protrusion 1343 has an arcuate chamfer; alternatively, the connection between the first top surface 1341 and the first side surface 1342 of some positioning protrusions 1343 has an arcuate chamfer. When the first positioning portion 134 includes a positioning protrusion ring 1344 disposed circumferentially along the second portion 114, the connection between the first top surface 1341 and the first side surface 1342 of the entire positioning protrusion ring 1344 has an arcuate chamfer. Alternatively, the positioning protrusion ring 1344 may protrude toward the first portion 113, or in other words, the top of the positioning protrusion ring 1344 may be an arcuate bent edge.

[0098] This embodiment provides a curved chamfer at the junction of the first top surface 1341 and the first side surface 1342. This reduces the chance of the first positioning portion 134 scratching the end cap 11 during assembly with the current collecting tray 13, and even prevents the first positioning portion 134 from scratching the end cap 11. This prevents metal debris from being generated by scratches on the end cap 11, which could cause a short circuit within the energy storage device 1, thereby improving the safety of the energy storage device 1. Furthermore, the curved chamfer at the junction of the first top surface 1341 and the first side surface 1342 facilitates the assembly and positioning of the end cap 11 on the current collecting tray 13, reduces the difficulty of assembly, and reduces the tooling requirements for a single weld.

[0099] The first positioning portion 134 has two structural forms. Referring to FIG. 19 to FIG. 21 , in one embodiment, the first positioning portion 134 includes a positioning protruding ring 1344 disposed along the circumference of the second portion 114 .

[0100] The first positioning portion 134 includes a positioning collar 1344 disposed circumferentially along the second portion 114. Alternatively, the positioning collar 1344 may be an annular structure extending around the entire circumference of the body 131. Alternatively, the positioning collar 1344 may be formed by stamping the body 131. The second surface 131b of the body 131 is stamped in a direction from the second surface 131b to the first surface 131a, thereby forming the positioning collar 1344 on the first surface 131a. Alternatively, the positioning collar 1344 may be formed by folding the body 131b.

[0101] First, positioning collar 1344 enhances structural strength and reduces the likelihood of distortion of current collecting disc 13. Second, the area of ​​the outer wall of positioning collar 1344 abutting the inner wall of second portion 114 of end cap 11 is relatively large, further increasing the flow area between end cap 11 and current collecting disc 13, thereby further improving the flow capacity of both. Third, positioning collar 1344 reduces the likelihood of molten solder flowing into the gap between end cap 11 and current collecting disc 13 during welding, and can even prevent molten solder from flowing into the gap between end cap 11 and current collecting disc 13, thereby reducing the likelihood of internal short circuits in energy storage device 1.

[0102] Please refer to FIG. 14-FIG . 15 and FIG. 18 . In one embodiment, the first positioning portion 134 includes a plurality of positioning protrusions 1343 that are spaced apart.

[0103] The first positioning portion 134 includes a plurality of positioning protrusions 1343 arranged at intervals. Optionally, the number of the positioning protrusions 1343 is at least three. Optionally, the spacing between any two adjacent positioning protrusions 1343 is equal. Optionally, a plurality of positioning protrusions 1343 are arranged on the first surface 131a at equal intervals along the circumference of the second portion 114. Optionally, the positioning protrusions 1343 are obtained by stamping the main body 131. The second surface 131b of the main body 131 is stamped from the second surface 131b to the first surface 131a to form the positioning protrusions 1343 provided on the first surface 131a. The position of the positioning protrusion 1343 can be set according to product requirements, thereby improving the versatility of applicability when assembling the collecting plate 13 and the end cover 11.

[0104] Please refer to Figure 22. In one embodiment, the positioning protrusion 1343 is inclined toward the direction close to the central axis of the main body 131, and the angle α between the outer peripheral side of the positioning protrusion 1343 facing away from the central axis of the main body 131 and the first surface 131a (as shown in α in Figure 22) is 80°≤α≤85°.

[0105] In this embodiment, the positioning protrusion 1343 is inclined toward the direction close to the central axis of the main body 131, so that part of the outer peripheral side surface of the first positioning portion 134 abuts against part of the outer peripheral side surface of the second portion 114, which is beneficial to positioning the end cover 11 when it is installed on the collecting plate 13. It not only reduces the difficulty of assembly operation, improves the accuracy of installation of the end cover 11 on the collecting plate 13, but also reduces the tooling requirements for one-time welding.

[0106] Optionally, the positioning protrusion 1343 is formed by stamping the body 131. The second surface 131b of the body 131 is stamped in a direction from the second surface 131b to the first surface 131a, thereby forming an inclined positioning protrusion 1343. It can also be understood that the positioning protrusion 1343 in this embodiment is a folded protrusion that is bent approximately 90 degrees toward the first portion 113, and the outer folded protrusion can be tilted 5-10 degrees toward the center.

[0107] Optionally, an angle α between the outer peripheral side surface of the positioning protrusion 1343 facing away from the central axis of the body 131 and the first surface 131a satisfies the following range: 80°≤α≤85°. Specifically, the value of the angle α can be, but is not limited to, 80°, 81°, 82°, 83°, 84°, and 85°.

[0108] In this embodiment, when the angle α satisfies the range of 80°≤α≤85°, it not only facilitates positioning of the end cap 11 when mounted on the current collecting tray 13, but also reduces the chance of the first positioning portion 134 scratching the end cap 11. If the angle α is too small, positioning of the end cap 11 when mounted on the current collecting tray 13 is difficult; if the angle α is too large, the first positioning portion 134 may easily directly abut the end cap 11, causing the first positioning portion 134 to damage the end cap 11.

[0109] Please refer to FIG. 14 , FIG. 15 , FIG. 18 , and FIG. 22 . In one embodiment, the body 131 has a plurality of first through holes 135 penetrating the first surface 131 a and the second surface 131 b .

[0110] In this embodiment, the body 131 has a plurality of first through holes 135 that penetrate the first surface 131a and the second surface 131b. Optionally, the number of the first through holes 135 is 2-6. Further optionally, the number of the first through holes 135 is 3. Optionally, the spacing between any two adjacent first through holes 135 is equal. In other words, the plurality of first through holes 135 are distributed on the body 131 at equal intervals. By providing the plurality of first through holes 135 on the body 131, it is beneficial for the electrolyte to enter through the first through holes 135, quickly infiltrate the electrode assembly 14, and improve the infiltration efficiency of the electrolyte.

[0111] Please refer to Figures 14, 15, 18, and 22. In one embodiment, at least one of the first through holes 135 and at least one of the positioning protrusions 1343 connected to the inner wall of the first through hole 135 constitute a first folding group, and the first folding group and the main body 131 are integrally formed through a stamping process.

[0112] In this embodiment, the second surface 131b of the body 131 is stamped in a direction from the second surface 131b to the first surface 131a to simultaneously form the positioning protrusion 1343 and the first through hole 135 provided on the body 131. In other words, two structures, a first through hole 135 and a positioning protrusion 1343, can be obtained through a single stamping process, thereby reducing the preparation steps of the energy storage device 1 and improving the preparation efficiency of the energy storage device 1.

[0113] Please refer to Figures 14, 15, and 18. In one embodiment, the first surface 131a of the main body 131 is provided with a plurality of spaced-apart limiting protrusions 136, and the outer peripheral side surfaces of the limiting protrusions 136 are spaced-apart from the outer peripheral side surfaces of the main body 131. The end cover 11 includes a first portion 113 and a second portion 114 bent and connected to the periphery of the first portion 113. The surface of the second portion 114 close to the main body 131 is connected to the first surface 131a, and the surface of the limiting protrusion 136 facing away from the main body 131 abuts against the surface of the first portion 113 facing the main body 131.

[0114] The end cap 11 provided in this embodiment includes a first portion 113 and a second portion 114 connected by a bend. The first portion 113 is positioned further away from the collecting tray 13 than the second portion 113. The first portion 113 and the second portion 114 are arranged at an angle. The side of the second portion 114 facing away from the first portion 113 is connected to the first surface 131a. A gap exists between the surface of the first portion 113 facing the collecting tray 13 and the first surface 131a. The shape of the end cap 11 can also be understood as that of a bottle cap.

[0115] The body 131 provided in this embodiment is provided with a stopper protrusion 136 for limiting and supporting the end cap 11. The surface of the stopper protrusion 136 facing away from the body 131 abuts the surface of the first portion 113 facing the body 131. In other words, the stopper protrusion 136 abuts the first portion 113 to support the end cap 11. Alternatively, the end cap 11 includes a second portion 114 extending from the first portion 113 toward the collecting plate 13, with the second portion 114 covering the stopper protrusion 136. One end of the stopper protrusion 136 abuts the first portion 113, and the other end abuts the first surface 131a. The distance from the surface of the limiting protrusion 136 facing the main body 131 to the surface of the limiting protrusion 136 facing away from the main body 131 is equal to the distance from the first surface 131a of the main body 131 to the surface of the first part 113 facing the main body 131. In other words, the height of the limiting protrusion 136 is equal to the distance from the first surface 131a of the main body 131 to the surface of the first part 113 facing the main body 131.

[0116] Optionally, the number of the limiting protrusions 136 is 2-6. Further optionally, the number of the limiting protrusions 136 is 3. Optionally, the spacing between any two adjacent limiting protrusions 136 is equal. In other words, a plurality of limiting protrusions 136 are distributed on the first surface 131a at equal intervals. Optionally, the limiting protrusions 136 are obtained by stamping the main body 131. The second surface 131b of the main body 131 is stamped from the second surface 131b to the first surface 131a to form a limiting protrusion 136 provided on the first surface 131a. Optionally, the plurality of limiting protrusions 136 are arranged near the central axis of the collecting plate 13. The plurality of limiting protrusions 136 can support the middle area of ​​the collecting plate 13, prevent the collecting plate 13 and the end cover 11 from deformation, and improve the structural strength of the energy storage device 1.

[0117] Optionally, when the first surface 131a of the body 131 is provided with a plurality of spaced-apart limiting protrusions 136 and a first positioning portion 134, the plurality of limiting protrusions 136 are closer to the central axis of the body 131 than the first positioning portion 134. It can also be understood that the limiting protrusions 136 are protrusions provided on the inner ring of the first surface 131a, and the first positioning portion 134 is a structural component provided on the outer ring of the first surface 131a.

[0118] In this embodiment, a limiting protrusion 136 is provided on the first surface 131a of the main body 131, so that the limiting protrusion 136 abuts the first portion 113 of the end cover 11 to support the end cover 11, thereby improving the structural strength of the end cover 11 and the current collecting plate 13. When the energy storage device 1 is impacted, the limiting protrusion 136 can abut the end cover 11, for example, preventing the current collecting plate 13 and the end cover 11 from bulging upward or sinking downward, thereby reducing the degree of deformation of the current collecting plate 13 and the end cover 11, and further improving the structural strength of the energy storage device 1.

[0119] Optionally, the first portion 113 of the end cap 11 is provided with an explosion-proof valve 111 for discharging gas generated within the energy storage device 1. The limiting protrusion 136 and the first portion 113 enclose a gas collection space for accommodating the gas generated within the energy storage device 1. In this embodiment, by providing the limiting protrusion 136 on the first surface 131a of the body 131, a gas collection space is formed below the explosion-proof valve 111 of the end cap 11. This facilitates the accumulation of gas generated within the energy storage device 1. When the gas pressure reaches a preset value, the gas is discharged through the explosion-proof valve 111, preventing explosion and further improving the safety performance of the energy storage device 1.

[0120] Please refer to Figure 14. In one embodiment, the limiting protrusion 136 includes a second top surface 1361 facing away from the first surface 131a, and a second side surface 1362 bent and connected to the second top surface 1361. The second side surface 1362 is also connected to the first surface 131a. The connection between the second top surface 1361 and the second side surface 1362 has an arc chamfer.

[0121] In this embodiment, the connection between the second top surface 1361 and the second side surface 1362 has a curved chamfer. This can also be understood as the connection between the second top surface 1361 and the second side surface 1362 being a curved surface, which protrudes in a direction away from the first surface 131a, or in other words, the curved surface protrudes in a direction close to the first portion 113 of the end cover 11. Optionally, the connection between the second top surface 1361 and the second side surface 1362 of each limiting protrusion 136 has a curved chamfer; or, the connection between the second top surface 1361 and the second side surface 1362 of some limiting protrusions 136 has a curved chamfer.

[0122] In this embodiment, the connection between the second top surface 1361 and the second side surface 1362 is provided with an arc chamfer, so that when the end cover 11 and the collecting plate 13 are assembled, the probability of the limiting protrusion 136 scratching the end cover 11 is reduced, and even the limiting protrusion 136 scratching the end cover 11 is avoided, thereby preventing the end cover 11 from generating metal debris due to scratches, affecting the working performance of the energy storage device 1, and thereby improving the stability of the energy storage device 1.

[0123] Please refer to FIG. 14 , in one embodiment, the peripheral side surface of the limiting protrusion 136 is perpendicular to the first surface 131 a .

[0124] In this embodiment, the circumferential side surface of the limiting protrusion 136 is perpendicular to the first surface 131a, or in other words, the limiting protrusion 136 is perpendicular to the main body 131, which is conducive to the limiting protrusion 136 abutting the first part 113 of the end cover 11 to support the end cover 11, thereby improving the structural strength of the end cover 11 and the collecting plate 13.

[0125] Optionally, the limiting protrusion 136 is formed by stamping the body 131. By stamping the second surface 131b of the body 131 in a direction from the second surface 131b to the first surface 131a, the limiting protrusion 136 can be formed perpendicular to the first surface 131a. It can also be understood that the limiting protrusion 136 in this embodiment is a folded protrusion that is folded 90° toward the first portion 113.

[0126] Please refer to FIG. 14 and FIG. 15 . In one embodiment, the body 131 has a plurality of second through holes 137 penetrating the first surface 131 a and the second surface 131 b . The second through holes 137 are used to allow the electrolyte to flow into the housing 12 .

[0127] In this embodiment, the body 131 has a plurality of second through holes 137 that penetrate the first surface 131a and the second surface 131b. Optionally, the number of the second through holes 137 is 2-6. Further optionally, the number of the second through holes 137 is 3. Optionally, the spacing between any two adjacent second through holes 137 is equal. In other words, the plurality of second through holes 137 are distributed on the body 131 at equal intervals. By providing a plurality of second through holes 137 on the body 131, it is beneficial for the electrolyte to enter through the second through holes 137, quickly infiltrate the electrode assembly 14, and improve the infiltration efficiency of the electrolyte.

[0128] Please refer to Figures 14 and 15 together. In one embodiment, at least one of the second through holes 137 and at least one of the limiting protrusions 136 connected to the inner wall of the second through hole 137 constitute a second folding group, and the second folding group and the main body 131 are integrally formed by a stamping process.

[0129] In this embodiment, the second surface 131b of the body 131 is stamped in a direction from the second surface 131b to the first surface 131a, thereby simultaneously forming the limiting protrusion 136 and the second through hole 137 provided on the body 131. In other words, two structures, a second through hole 137 and a limiting protrusion 136, can be obtained through a single stamping process, thereby reducing the manufacturing process of the energy storage device 1 and improving the manufacturing efficiency of the energy storage device 1.

[0130] Please refer to Figures 1 to 3, 15, 20, and 21. In one embodiment, the energy storage device 1 further includes an electrode assembly 14. The shell 12 has a accommodating cavity 121. The electrode assembly 14 is disposed in the accommodating cavity 121. The electrode assembly 14 is in a wound state and forms a hollow structure 141. The second surface 131b of the body 131 is provided with a second positioning portion 138. At least a portion of the second positioning portion 138 is inserted into the hollow structure 141.

[0131] The energy storage device 1 provided in this embodiment also includes an electrode assembly 14, and the electrode assembly 14 is arranged in the accommodating cavity 121. The energy storage device 1 also includes an electrolyte (not shown) arranged in the accommodating cavity 121, and the electrolyte at least partially infiltrates the electrode assembly 14. The electrode assembly 14 is connected to the second surface 131b of the current collecting disk 13. For example, the electrode assembly 14 is welded to the current collecting disk 13. The electrode assembly 14 is in a wound state and forms a hollow structure 141. The hollow structure 141 here is an electrically insulating structural tube formed by winding a plurality of layers of diaphragms. Optionally, the hollow structure 141 is located at the center of the electrode assembly 14.

[0132] The main body 131 provided in this embodiment is provided with a second positioning portion 138 to facilitate the assembly of the current collecting plate 13 on the electrode assembly 14 for positioning. At least a portion of the second positioning portion 138 is inserted into the hollow structure 141. For example, a portion of the second positioning portion 138 is inserted into the hollow structure 141. For another example, the second positioning portion 138 is completely inserted into the hollow structure 141. For example, the second positioning portion 138 abuts against the inner side wall of a portion of the hollow structure 141. For another example, the second positioning portion 138 is spaced apart from the hollow structure 141. Optionally, the second positioning portion 138 is a raised structure, and at least a portion of the raised structure is inserted into the hollow structure 141.

[0133] In this embodiment, a second positioning portion 138 is provided on the second surface 131b of the main body 131, so that at least a portion of the second positioning portion 138 is inserted into the hollow structure 141, so as to facilitate positioning when the collecting plate 13 and the electrode assembly 14 are assembled. This not only reduces the difficulty of assembly operation, improves the accuracy of assembly of the collecting plate 13 and the electrode assembly 14, but also reduces the tooling requirements for one-time welding.

[0134] Optionally, the second positioning portion 138 is located at the center of the current collecting disc 13, and the hollow structure 141 is located at the center of the electrode assembly 14. In this embodiment, the second positioning portion 138 is provided on the second surface 131b of the body 131 to perform a positioning function. When the current collecting disc 13 and the electrode assembly 14 are assembled, the center of the current collecting disc 13 corresponds to the center of the electrode assembly 14. In other words, the central axes of the current collecting disc 13 and the electrode assembly 14 coincide with each other, or the centers of the circles of the current collecting disc 13 and the electrode assembly 14 are aligned, thereby improving the assembly stability of the energy storage device 1.

[0135] Please refer to Figures 1 to 3, 15, 20, and 21. In one embodiment, the main body 131 has a first liquid injection hole 133 that passes through the first surface 131a and the surface of the second positioning portion 138 facing the electrode assembly 14, and the first liquid injection hole 133 is within the scope of the hollow structure 141 when the orthographic projection of the surface of the electrode assembly 14 facing the collecting plate 13 falls. The end cover 11 has a second liquid injection hole 112, and the end cover 11 and the collecting plate 13 are surrounded to form a cavity 115. The first liquid injection hole 133 and the second liquid injection hole 112 are both connected to the cavity 115.

[0136] In this embodiment, the body 131 has a first injection hole 133 extending through the first surface 131a and the second positioning portion 138 on a side facing the electrode assembly 14. In other words, the first injection hole 133 extends through the first surface 131a and the second positioning portion 138 on a side facing away from the end cap 11. Furthermore, the orthographic projection of the first injection hole 133 on the surface of the electrode assembly 14 facing the current collecting plate 13 falls within the range of the hollow structure 141. In other words, the first injection hole 133 is disposed opposite the hollow structure 141. Optionally, the first injection hole 133 is disposed adjacent to or directly aligned with the center of the electrode assembly 14. Optionally, the second positioning portion 138 is a convex ring structure, at least a portion of which is inserted into the hollow structure 141.

[0137] In this embodiment, the end cap 11 has a second liquid injection hole 112. The end cap 11 and the current collecting plate 13 enclose a cavity 115. The first liquid injection hole 133 and the second liquid injection hole 112 are both connected to the cavity 115. The electrolyte can flow into the cavity 115 through the second liquid injection hole 112, and then flow from the cavity 115 to the second liquid injection hole 112. Optionally, the first liquid injection hole 133 and the second liquid injection hole 112 are arranged correspondingly.

[0138] After prolonged use, the hollow structure 141 of the electrode assembly 14 reaches a relatively high temperature, which in turn increases the migration speed of active ions in the electrolyte within the hollow structure 141 of the electrode assembly 14 and increases side reactions, causing the electrolyte within the hollow structure 141 of the electrode assembly 14 to be consumed more quickly. Therefore, by providing a first injection hole 133 extending through the surface of the second positioning portion 138 facing the electrode assembly 14, and with the orthographic projection of the first injection hole 133 on the surface of the electrode assembly 14 facing the current collecting plate 13 falling within the hollow structure 141, the electrolyte can flow through the first injection hole 133 and infiltrate the electrode assembly 14. In other words, the electrolyte will directly infiltrate the hollow structure 141 of the electrode assembly 14, which helps ensure sufficient electrolyte within the hollow structure 141 of the electrode assembly 14 and thereby improves the cycle life of the battery. Moreover, when the electrolyte directly infiltrates the hollow structure 141 of the electrode assembly 14, the electrolyte will diffuse from the hollow structure 141 of the electrode assembly 14 to the surrounding areas, so that the electrode assembly 14 has a uniform injection effect in all directions, thereby enhancing the uniformity of the electrolyte in the electrode assembly 14 and helping to improve the performance of the energy storage device 1.

[0139] Please refer to Figure 23, which is a schematic diagram of the structure of an electric device according to an embodiment of the present application. The present application also provides an electric device 2, which includes a device body 21 and an energy storage device 1 provided above, which supplies power to the device body 21.

[0140] Optionally, the power-consuming device 2 in the embodiments of the present application may be, but is not limited to, a portable electronic device such as a mobile phone, tablet computer, laptop computer, desktop computer, smart toy, smart bracelet, smart watch, e-reader, game console, toy, or the like; it may also be a large device such as a battery-powered vehicle, electric vehicle, ship, or spacecraft. It is understood that the power-consuming device 2 in this embodiment is merely one form of power-consuming device 2 in which a battery is applied, and should not be construed as limiting the power-consuming device 2 provided in this application, nor should it be construed as limiting the batteries provided in various embodiments of this application.

[0141] The electrical device 2 provided in this embodiment, by adopting the energy storage device 1 provided above in this application, disposing the collecting plate 13 between the end cover 11 and the housing 12 and welding it to the circumferential side surfaces of the end cover 11 and the housing 12, can increase the welding area between the end cover 11 and the collecting plate 13, improve the flow capacity between the end cover 11 and the collecting plate 13, and improve the connection strength between the end cover 11 and the collecting plate 13 and the housing 12. When the energy storage device 1 supplies power to the device body 21, the energy storage device 1 can provide a stable power supply to the device body 21.

[0142] Please refer to Figures 1 to 22, and Figure 24. Figure 24 is a process flow chart of a welding method for an energy storage device in one embodiment of the present application. The present application also provides a welding method for an energy storage device 1, the welding method comprising S100, S200, and S300. S100, S200, and S300 are described in detail as follows. The welding method comprises:

[0143] S100 , providing an end cover 11 , a shell 12 , and a collecting plate 13 .

[0144] Optionally, an electrode assembly 14 is further provided. Further optionally, the electrode assembly 14 is a wound structure. Optionally, the electrode assembly 14 is in a wound state and forms a hollow structure 141 , and the current collecting disk 13 is provided with a second positioning portion 138 .

[0145] First, the wound electrode assembly 14 is placed into the housing 12, with the tabs of the electrode assembly 14 exposed at the opening of the housing 12. Then, the current collecting disc 13 is mounted on the electrode assembly 14. Specifically, the current collecting disc 13 is placed over the tabs of the wound electrode assembly 14. Subsequently, the current collecting disc 13 and the tabs are welded. Specifically, laser penetration welding is used to weld the positive electrode current collecting disc 13 and the tabs. For example, the weld width is 1 mm to 2 mm, and the weld depth is 2 mm to 4 mm.

[0146] Optionally, in the step of installing the current collecting plate 13 on the electrode assembly 14 , at least a portion of the second positioning portion 138 is inserted into the hollow structure 141 .

[0147] S200 , the end cover 11 is brought into contact with one side surface of the current collecting plate 13 , and the housing 12 is brought into contact with the surface of the current collecting plate 13 facing away from the end cover 11 , and the outer peripheral side surface of the current collecting plate 13 is exposed.

[0148] Optionally, the collecting plate 13 is provided with a first positioning portion 134, and the first positioning portion 134 and the second positioning portion 138 are provided on opposite sides of the collecting plate 13. The end cover 11 includes a first portion 113 and a second portion 114 bent and connected to the periphery of the first portion 113.

[0149] Optionally, in the step of abutting the end cover 11 against a side surface of the current collecting plate 13, the inner circumferential side surface of the second portion 114 is abutted against the outer circumferential side surface of the first positioning portion 134. Alternatively, the end cover 11 may be sleeved over the current collecting plate 13 so as to cover the outer circumferential surface of the first positioning portion 134.

[0150] S300, circumferential laser welding is performed on the outer peripheral side of the collecting disc 13 to fix the collecting disc 13 to the end cover 11 and the shell 12. The collecting disc 13 after the welding process includes a main body 131 and a welding portion 132. The main body 131 and the welding portion 132 are an integral structure. The main body 131 includes a first surface 131a and a second surface 131b arranged opposite to each other. The end cover 11 is connected to the first surface 131a of the main body 131, and the shell 12 is connected to the second surface 131b of the main body 131. The welding portion 132 is connected to the end cover 11, the shell 12, and the outer peripheral side surface of the main body 131.

[0151] Specifically, the end cap 11, current collecting plate 13, and housing 12 are horizontally placed on a welding jig and clamped. The laser welding head is aligned with the outer circumference of the current collecting plate 13. The laser welding head is then activated and the clamping jig is rotated at a constant speed. After one full rotation, the side seal weld is completed. The specific structure of the welded energy storage device 1 is described above and will not be further elaborated.

[0152] The welding method for the energy storage device 1 provided in this embodiment is simple and highly operable. By positioning the collecting plate 13 between the end cap 11 and the housing 12 and using a one-time welding tool to weld the collecting plate 13 to the circumferential side surfaces of the end cap 11 and the housing 12, a side-sealed weld is achieved. This increases the welding area between the end cap 11 and the collecting plate 13, improves the flow capacity between the end cap 11 and the collecting plate 13, and enhances the connection strength between the end cap 11, the collecting plate 13, and the housing 12.

[0153] Please refer to Figures 13 and 25. Figure 25 is a process flow chart of a welding method for an energy storage device in another embodiment of the present application. In one embodiment, in S200, the step of exposing the outer peripheral side of the collecting plate 13 includes:

[0154] S210 , making the collecting plate 13 protrude from the end cover 11 and the housing 12 .

[0155] Specifically, the end cap 11, current collecting plate 13, and housing 12 are horizontally placed on a welding jig and clamped. The laser welding head is adjusted to align with the weld protrusion of the current collecting plate 13 protruding from the sidewalls of the end cap 11 and housing 12. The weld portion 132 of the energy storage device 1 obtained using the preparation method of the present application can be understood as the weld protrusion that melts after welding.

[0156] Before welding the collecting plate 13, end cap 11, and housing 12, the collecting plate 13 is configured to protrude from the end cap 11 and housing 12. Alternatively, the collecting plate 13 may include a weld collar protruding from the outer walls of the end cap 11 and housing 12. This allows the laser welding head to directly heat the collar, while the housing 12 rotates at a constant speed to form a single weld. At this point, the collar is first heated and melted, forming a "melt top." This means that the melted collar flows to both sides under the influence of gravity, filling the gap between the end cap 11 and the collecting plate 13, or between the housing 12 and the collecting plate 13, and then fuses with the subsequently melted end cap 11 and housing 12, further enhancing the structural strength and airtightness of the weld area. Alternatively, the collar can melt to form solder. Furthermore, due to the "melt top" effect of the collar, the machining accuracy requirements for the joint surface between the end cap 11 and housing 12 are reduced, thereby reducing the processing cost of the components of the energy storage device 1.

[0157] Please refer to Figure 13. In one embodiment, in S200, in the step of exposing the outer peripheral side of the collecting plate, that is, in S210, in the step of making the collecting plate 13 protrude from the end cover 11 and the shell 12, the width L3 of the collecting plate 13 protruding from the end cover 11 and the shell 12 satisfies the following range: 0.25mm≤L3≤2mm.

[0158] Before welding the collecting plate 13, end cap 11, and housing 12, the width L3 of the collecting plate 13 protruding from the end cap 11 and housing 12 satisfies the following range: 0.25 mm ≤ L3 ≤ 2 mm. Alternatively, the width L3 of the welded protruding ring protruding from the end cap 11 and housing 12 satisfies the following range: 0.25 mm ≤ L3 ≤ 2 mm. This width L3 refers to the distance from the outer sidewall of the collecting plate 13 to the outer sidewall of the end cap 11, or from the outer sidewall of the collecting plate 13 to the outer sidewall of the housing 12. Specifically, the value of the width L3 can be, but is not limited to, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, and 2mm, etc.

[0159] In this embodiment, when the width L3 satisfies the range of 0.25mm≤L3≤2mm, not only can the machining accuracy requirements of the joint surface between the end cap 11 and the shell 12 be reduced, and the structural strength and airtightness of the weld area be improved, but the welding process time can also be reduced, welding efficiency can be improved, and production costs can be reduced. If the size of L3 is too small, it will be detrimental to the alignment of the laser welding head, the increase in the machining accuracy requirements of the joint surface between the end cap 11 and the shell 12, and it will be detrimental to the welding convex ring after melting to weld the end cap 11 and the shell 12, reducing the structural strength and airtightness of the weld area. If the size of L3 is too large, the welding process time will be increased, welding efficiency will be reduced, and production costs will also be increased.

[0160] The above is a detailed introduction to the contents provided in the implementation mode of the present application. This article explains and illustrates the principles and implementation modes of the present application. The above explanation is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation mode and application scope. In summary, the contents of this specification should not be understood as limiting the present application.

Claims

1. An energy storage device, characterized in that: The energy storage device includes an end cover, a shell, and a current collecting plate arranged between the end cover and the shell, the current collecting plate includes a body and a welding portion, the body and the welding portion are an integral structure, the body includes a first surface and a second surface arranged opposite to each other, the end cover is connected to the first surface of the body, the shell is connected to the second surface of the body, and the welding portion is connected to the end cover, the shell, and the outer peripheral side of the body.

2. The energy storage device according to claim 1, characterized in that The collecting plate satisfies at least one of the following conditions: Along the radial direction of the collecting plate, the outer peripheral side surface of the body is flush with the outer peripheral side surface of the end cover and / or the outer peripheral side surface of the shell; Along the radial direction of the collecting plate, the outer peripheral side surface of the body protrudes beyond the outer peripheral side surface of the end cover and / or the outer peripheral side surface of the shell.

3. The energy storage device according to claim 2, characterized in that: A width L1 of the welding portion protruding from the end cover satisfies the following range: 0.05 mm ≤ L1 ≤ 1.45 mm; and / or a width L2 of the welding portion protruding from the shell satisfies the following range: 0.05 mm ≤ L2 ≤ 1.45 mm.

4. The energy storage device according to claim 3, characterized in that: The outer peripheral side surface of the end cover is flush with the outer peripheral side surface of the shell.

5. The energy storage device according to claim 1, characterized in that: A first positioning portion is protruding from the first surface of the main body, and the outer peripheral side surface of the first positioning portion is spaced apart from the outer peripheral side surface of the main body. The end cover includes a first part and a second part bent and connected to the periphery of the first part. The surface of the second part close to the main body is connected to the first surface, and the inner peripheral side surface of the second part abuts against the outer peripheral side surface of the first positioning portion.

6. The energy storage device according to claim 5, characterized in that: An end of the first positioning portion facing away from the body is spaced apart from a surface of the first portion facing the body.

7. The energy storage device according to claim 5, characterized in that: The first positioning portion includes a first top surface facing away from the first surface, and a first side surface bent and connected to the first top surface. The first side surface is also connected to the first surface. A connection between the first top surface and the first side surface has an arc chamfer.

8. The energy storage device according to claim 5, characterized in that: The first positioning portion includes a positioning protruding ring disposed along the circumference of the second portion.

9. The energy storage device according to claim 5, characterized in that: The first positioning portion includes a plurality of positioning protrusions arranged at intervals.

10. The energy storage device according to claim 9, characterized in that: The positioning protrusion is inclined toward a direction close to the central axis of the body, and an angle α between an outer peripheral side surface of the positioning protrusion away from the central axis of the body and the first surface is 80°≤α≤85°.

11. The energy storage device according to claim 10, characterized in that: The body has a plurality of first through holes penetrating the first surface and the second surface.

12. The energy storage device according to claim 11, characterized in that: At least one of the first through holes and at least one of the positioning protrusions connected to the inner side wall of the first through hole form a first folding group, and the first folding group and the body are integrally formed by a stamping process.

13. The energy storage device according to claim 1, characterized in that: The first surface of the main body is provided with a plurality of spaced-apart limiting protrusions, the outer peripheral side surfaces of the limiting protrusions are spaced-apart from the outer peripheral side surfaces of the main body, the end cover comprises a first part, and a second part bent and connected to the periphery of the first part, the surface of the second part close to the main body is connected to the first surface, and the surface of the limiting protrusion facing away from the main body abuts against the surface of the first part facing the main body.

14. The energy storage device according to claim 1, characterized in that: The energy storage device also includes an electrode assembly, the shell has a accommodating cavity, the electrode assembly is arranged in the accommodating cavity, the electrode assembly is in a wound state and forms a hollow structure, the second surface of the body is provided with a second positioning portion, and at least a portion of the second positioning portion is inserted into the hollow structure.

15. The energy storage device according to claim 14, characterized in that: The main body has a first liquid injection hole that passes through the first surface and the second positioning portion on the side away from the end cover, and the first liquid injection hole is projected within the range of the hollow structure on the surface of the electrode assembly facing the current collecting plate, and the end cover has a second liquid injection hole. The end cover and the current collecting plate are arranged to form a cavity, and the first liquid injection hole and the second liquid injection hole are both connected to the cavity.

16. An electrical equipment, characterized in that: The electrical equipment includes: The device itself; and The energy storage device according to any one of claims 1 to 15, wherein the energy storage device supplies power to the device body.

17. A welding method for an energy storage device, characterized in that: The welding method comprises: Provide end caps, housings, and collector plates; The end cover is abutted against one side surface of the current collecting plate, and the shell is abutted against the surface of the current collecting plate facing away from the end cover, and the outer peripheral side surface of the current collecting plate is exposed; The outer peripheral side of the collecting disc is circumferentially laser welded so that the collecting disc is fixedly connected to the end cover and the shell. The collecting disc after the welding process includes a main body and a welding portion. The main body and the welding portion are an integral structure. The main body includes a first surface and a second surface arranged opposite to each other. The end cover is connected to the first surface of the main body, and the shell is connected to the second surface of the main body. The welding portion is connected to the end cover, the shell, and the outer peripheral side of the main body.

18. The welding method according to claim 17, characterized in that: In the step of exposing the outer peripheral side surface of the collecting plate, a width L3 of the collecting plate protruding from the end cover and the shell satisfies the following range: 0.25 mm ≤ L3 ≤ 2 mm.

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