Energy storage device and processing and manufacturing process thereof

Abstract

The invention relates to an energy storage device and a processing and manufacturing process thereof, the energy storage device comprises a shell, a battery cell, a cover plate, an insulation sealing piece and a direct-connection inward-rolling sealed electrode leading-out structure, and the electrode leading-out structure comprises a current collecting disc part, a large-diameter cylinder part, a small-diameter cylinder part, a rolling edge, a rolling edge groove and a through hole; the current collecting disc part is disc-shaped and is used for collecting current of the battery cell; a large-diameter cylindrical part is arranged in the center of the flow collecting disc part; a small-diameter cylindrical part is arranged in the center of the top of the large-diameter cylindrical part, and the large-diameter cylindrical part and the small-diameter cylindrical part are coaxially arranged; a turned edge surrounding the small-diameter cylindrical part is arranged on the outer ring of the top of the large-diameter cylindrical part; a curled edge groove is formed between the curled edge and the small-diameter cylindrical part; the turned edge is used for abutting against the upper surface of the insulation sealing piece of the energy storage device after being turned up, pressure is applied to the insulation sealing piece, and the sealing effect of the insulation sealing piece is guaranteed. Through the electrode lead-out structure which is directly connected and internally rolled and sealed, the processing and manufacturing efficiency can be improved, the manufacturing cost is reduced, and the assembling efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical energy storage, and in particular to an energy storage device and a processing and manufacturing process thereof. Background Art

[0002] With the rapid emergence and development of new technologies in the fields of information technology, electronic products and new energy vehicles, the research and development of energy storage capacitors has received more and more attention. Energy storage capacitors are a new type of energy storage device between traditional capacitors and rechargeable batteries. They have both the large current fast charging and discharging characteristics of capacitors and the energy storage characteristics of batteries. Their capacity can reach several thousand farads. Compared with traditional capacitors, energy storage capacitors have higher capacity, and compared with batteries, they have the advantages of fast charging speed, high energy density, wide operating temperature range and long cycle life, and they are pollution-free to the environment. They are especially suitable for high-frequency, high-power and high-energy charging and discharging applications. Therefore, they have a wide market demand in national strategic emerging industries such as rail transit, wind power generation, public buses, electric vehicles, and smart grids.

[0003] At present, the electrode lead-out mechanism of the energy storage capacitor mainly includes a pole, a transfer plate, a current collector, a cover plate and an insulating seal. For example, a Chinese patent document with publication number CN112821015A discloses a copper-aluminum composite pole, negative electrode cover plate assembly structure and energy storage unit, wherein a battery cell is inserted into the shell of the energy storage unit, and the top of the battery cell is fixedly connected to the negative electrode cover plate assembly through the negative electrode collector plate, and the negative electrode cover plate assembly includes a negative pole assembly, a first cover plate, a first insulating member, and a second insulating member; the negative pole assembly includes a pole and a chassis, a second center hole is opened in the center of the chassis, and a first boss is provided at the bottom of the pole, the outer diameter of the first boss is slightly larger than the inner diameter of the second center hole of the chassis, the first boss is pressed into the second center hole, and the two are interference fit, thereby realizing a fixed connection between the pole and the chassis, and the chassis is fixed to the negative electrode collector plate by welding; the first cover plate is sleeved on the outer periphery of the pole of the negative pole assembly, and a first insulating member and a second insulating member are sequentially arranged between the first cover plate and the pole from top to bottom for insulation, and the corresponding surfaces of the first insulating member and the second insulating member abut against each other. However, in the above-mentioned negative electrode lead-out mechanism, the negative electrode column and the chassis as the adapter plate are connected by interference fit, and the negative electrode column assembly and the first cover plate are provided with a first insulating member and a second insulating member to play the role of insulation and sealing. The structure is complex and there are many parts, which leads to low production and assembly efficiency, cumbersome processing and manufacturing process of energy storage capacitors, and high manufacturing cost. The Chinese patent document with announcement number CN210984547U discloses a negative electrode lead-out structure and an energy storage monomer, wherein the negative electrode adapter plate and the cover plate are both provided with a central hole, and the negative electrode column passes through the central hole of the negative electrode adapter plate and the cover plate and is electrically connected to the negative electrode adapter plate; a sealing ring is provided between the negative electrode column and the cover plate for electrical insulation; an insulating plastic block is fixed to the outer periphery of the negative electrode column, and the lower end face of the insulating plastic block is pressed against the upper end face of the cover plate; a first step is provided on the outer periphery of the negative electrode adapter plate, and when the negative electrode adapter plate is welded to the negative current collector, the outer periphery of the first step is inserted into the inner diameter of the flange of the negative current collector. Due to the provision of a negative current collector, a negative electrode adapter, a cover plate, a negative electrode column, and an insulating plastic block, the connections between these components and the entire negative electrode lead-out structure also have the problems of complex structure, low manufacturing and assembly efficiency, and high cost.

[0004] Therefore, it is urgent to improve the electrode lead-out mechanism of the energy storage device and its processing and manufacturing process, to solve the problems of complex structure and inconvenient assembly and connection between the electrode poles, adapter plates, current collectors, cover plates and insulating seals, to improve the processing and manufacturing efficiency of energy storage capacitors and reduce production costs. Summary of the invention

[0005] The present invention provides an energy storage device and a processing and manufacturing process thereof, which can improve the processing and manufacturing efficiency of the energy storage device, reduce the manufacturing cost, and improve the assembly efficiency through a directly connected inner-rolled sealed electrode lead-out structure.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] An energy storage device comprises a shell, a battery cell, a cover plate, an insulating seal and an electrode lead-out structure. The shell is a barrel-shaped structure with an opening at one end. The battery cell is arranged in the shell, and the cover plate is fixedly connected to the open end of the shell. An opening is arranged in the center of the cover plate. The electrode lead-out structure is connected to the battery cell and extends out from the opening in the center of the cover plate. The insulating seal is arranged between the electrode lead-out structure and the opening in the center of the cover plate, and is used to insulate the electrode lead-out structure and the cover plate, and to seal the opening in the center of the cover plate. The electrode lead-out structure is an electrode lead-out structure that is directly connected to an inner roll seal. The electrode lead-out structure comprises a current collecting disc portion, a large diameter cylindrical portion, a small diameter cylindrical portion, a roll The invention discloses a method for manufacturing a battery comprising the following steps: a first electrode of the battery pack and a second electrode of the battery pack having a plurality of electrodes. The first electrode of the battery pack comprises a first electrode and a second electrode of the battery pack. The first electrode of the battery pack comprises a first electrode and a second electrode of the battery pack. The first electrode of the battery pack comprises a first electrode and a second electrode of the battery pack. The first electrode of the battery pack comprises a first electrode and a second electrode of the battery pack. The first electrode of the battery pack comprises a first electrode and a second electrode of the battery pack.

[0008] Further, the collecting disc portion, the large diameter cylindrical portion, the small diameter cylindrical portion and the curling edge are integrally formed.

[0009] Furthermore, the collecting disc portion is manufactured separately, and the large diameter cylindrical portion, the small diameter cylindrical portion and the curling edge are formed integrally; the large diameter cylindrical portion is fixedly connected to the central position of the collecting disc portion by laser welding.

[0010] Furthermore, a circular hole matching with the large diameter cylindrical part is provided at the central position of the collecting disc part, and the large diameter cylindrical part is inserted into the circular hole at the central position of the collecting disc part, and then fixedly connected to the central position of the collecting disc part by laser welding.

[0011] Furthermore, the material of the current collecting disk portion is copper, and the material of the large diameter cylindrical portion, the small diameter cylindrical portion and the curling edge is aluminum.

[0012] Furthermore, in the initial state before curling, the outer diameter of the small diameter cylindrical portion is smaller than the outer diameter of the large diameter cylindrical portion, the outer diameter of the curling is larger than the outer diameter of the large diameter cylindrical portion, the inner diameter of the curling is smaller than the outer diameter of the large diameter cylindrical portion, and the inner diameter of the curling is larger than the outer diameter of the small diameter cylindrical portion; and the height of the curling is greater than the height of the small diameter cylindrical portion.

[0013] A processing and manufacturing process for an energy storage device comprises the following steps: step 1, preparing an electrode lead-out structure; step 2, welding the lower surface of a current collecting disk portion of the electrode lead-out structure to the upper surface of a battery cell; step 3, sleeve a cover plate on a large-diameter cylindrical portion of the electrode lead-out structure through its central opening; and install an insulating seal between the large-diameter cylindrical portion and the central opening of the cover plate; or form the insulating seal by injection molding; step 4, curling the edge of the electrode lead-out structure to make it abut against the upper surface of the insulating seal; step 5, placing the assembly of the battery cell, the electrode and the cover plate into a shell, and connecting the cover plate to the upper end opening of the shell.

[0014] Furthermore, in step one, the electrode lead-out structure is formed in one piece. First, a blank is prepared, and a semi-finished product having a current collecting disc portion and a cylindrical portion is obtained by stamping. Then, a large-diameter cylindrical portion, a small-diameter cylindrical portion and a curled edge are formed by milling, and a through hole is formed on the current collecting disc portion.

[0015] Furthermore, in step three, the welding between the lower surface of the current collector and the upper surface of the battery cell is laser welding; in step four, the injection molding material is selected from one of polypropylene, polystyrene, polycarbonate, and nylon.

[0016] Furthermore, in step five, before placing the assembly of the battery cell, electrode and cover plate into the shell, the shell is pre-heated and expanded before assembly, and the heating temperature is between 150 and 200 degrees Celsius; the cover plate is kept flush with the upper end opening of the shell, and the cover plate and the shell are connected together by laser welding, the welding depth is 0.5 to 1.2 mm, and the spot overlap rate is 60 to 90%.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] 1. The electrode lead-out structure of the present invention adopts a direct-connected inner-rolled seal, and the current collecting disc portion, the large-diameter cylindrical portion, the small-diameter cylindrical portion and the rolled edge are formed in one piece, thereby improving the efficiency of processing and manufacturing.

[0019] 2. After the curling is turned over, it abuts against the upper surface of the insulating seal, thereby applying pressure to the insulating seal to ensure the sealing effect of the insulating seal.

[0020] 3. The current collecting disc can be manufactured separately, and the large diameter cylindrical part, the small diameter cylindrical part and the curling edge are formed in one piece, and then fixed and connected by laser welding. The material of the current collecting disc can be selected as copper, which can ensure good conductivity, and the material of the large diameter cylindrical part, the small diameter cylindrical part and the curling edge can be selected as aluminum, which improves the strength of the electrode on the basis of ensuring the conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the overall structure of the energy storage device of the present invention from the top view;

[0023] Figure 2 It is a schematic diagram of the overall structure of the bottom view of the energy storage device of the present invention;

[0024] Figure 3 is an overall cross-sectional view of the energy storage device of the present invention;

[0025] Figure 4 It is a structural schematic diagram of the electrode lead-out mechanism after crimping of the present invention;

[0026] Figure 5 is a cross-sectional view of the electrode lead-out mechanism after crimping of the present invention;

[0027] Figure 6 It is a structural schematic diagram of the electrode lead-out mechanism before crimping of the present invention;

[0028] Figure 7 is a cross-sectional view of the electrode lead-out mechanism before crimping of the present invention;

[0029] Figure 8 It is a process flow chart of the processing and manufacturing process of the energy storage device of the present invention.

[0030] Reference numerals in the figures:

[0031] Shell 1, process protrusion 11, reinforced fan groove 12, reinforced ring groove 13, battery cell 2, cover plate 3, insulating seal 4, electrode lead-out mechanism 5, current collecting disc portion 51, large diameter cylindrical portion 52, small diameter cylindrical portion 53, curling 54, curling groove 55, through hole 56. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0034] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present invention, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0035] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. The drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0036] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the examples can be practiced without these specific details.

[0037] At the same time, in this specification, descriptions involving orientations, such as up, down, left, right, front, back, inside, outside, longitudinal, lateral, vertical, horizontal, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0038] Embodiment 1

[0039] like Figure 1-3As shown, the energy storage device of the present invention is mainly composed of a shell 1, a battery cell 2, a cover plate 3, an insulating seal 4 and an electrode lead-out structure 5, wherein the shell 1 is a barrel-shaped structure with an opening at one end, the battery cell 2 is arranged in the shell 1, and the cover plate 3 is fixedly connected to the open end of the shell 1. An opening is provided in the center of the cover plate 3, the electrode lead-out structure 5 is connected to the battery cell 2 and extends out from the opening in the center of the cover plate 3, and the insulating seal 4 is arranged between the electrode lead-out structure 5 and the opening in the center of the cover plate 3, for insulating the electrode lead-out structure 5 from the cover plate 3 and sealing the opening in the center of the cover plate 3.

[0040] like Figure 4-7 As shown, the electrode lead-out structure 5 includes a current collecting disc portion 51, a large diameter cylindrical portion 52, a small diameter cylindrical portion 53, a curling edge 54, a curling edge groove 55, and a through hole 56. The current collecting disc portion 51 is disc-shaped, and serves to collect the current of the battery cell 2. A large diameter cylindrical portion 52 is arranged at the central position of the current collecting disc portion 51, and a plurality of through holes 56 are evenly spaced along the circumference around the large diameter cylindrical portion 52 on the current collecting disc portion 51. The number of through holes 56 is preferably 5-6. A small diameter cylindrical portion 53 is arranged at the top center of the large diameter cylindrical portion 52, and the large diameter cylindrical portion 52 and the small diameter cylindrical portion 53 are coaxially arranged. A curling edge 54 surrounding the small diameter cylindrical portion 53 is arranged on the top outer ring of the large diameter cylindrical portion 52. As shown Figure 6-7 As shown, a curling groove 55 is provided between the curling edge 54 and the small diameter cylindrical portion 53 .

[0041] The current collecting disc portion 51, the large diameter cylindrical portion 52, the small diameter cylindrical portion 53 and the curling edge 54 are formed integrally. Preferably, the electrode lead-out structure 5 is formed by first stamping the blank and then milling it.

[0042] like Figure 3 As shown, the current collecting disc portion 51 of the electrode lead-out structure 5 is fixedly connected to the battery cell 2 by laser welding. The large diameter cylindrical portion 52 is arranged in the opening in the center of the cover plate 3, the small diameter cylindrical portion 53 and the curling edge 54 extend out of the opening in the center of the cover plate 3, and the insulating seal 4 is located between the large diameter cylindrical portion 52 and the opening in the center of the cover plate 3. The curling edge 54 is rolled up and abuts against the upper surface of the insulating seal 4, so that pressure can be applied to the insulating seal 4 to ensure the sealing effect of the insulating seal 4. The large diameter cylindrical portion 52 and the small diameter cylindrical portion 53 together constitute the electrode of the energy storage device.

[0043] like Figure 7 As shown, in the initial state, the outer diameter of the small diameter cylindrical portion 53 is smaller than the outer diameter of the large diameter cylindrical portion 52, the outer diameter of the curling edge 54 is larger than the outer diameter of the large diameter cylindrical portion 52, the inner diameter of the curling edge 54 is smaller than the outer diameter of the large diameter cylindrical portion 52, and the inner diameter of the curling edge 54 is larger than the outer diameter of the small diameter cylindrical portion 53; and the height of the curling edge 54 is greater than the height of the small diameter cylindrical portion 53.

[0044] The material of the electrode lead-out mechanism 5 is selected to be a material with good electrical conductivity, preferably copper or aluminum.

[0045] like Figure 2-3 As shown, preferably, the bottom surface of the energy storage device housing 1 is provided with a reinforcement groove and a process protrusion 11, and the process protrusion 11 is arranged in the center of the bottom surface of the housing, which can support and fix the battery cell 2. The reinforcement groove includes a reinforcement ring groove 13 arranged in a circle around the bottom surface, and a plurality of reinforcement fan grooves 12 arranged between the reinforcement ring groove 13 and the process protrusion 11, and the plurality of reinforcement fan grooves 12 are evenly spaced along the circumferential direction, and the number of the reinforcement fan grooves 12 is preferably 5-6.

[0046] Preferably, a liquid injection hole is provided on the cover plate 3 ; and an explosion-proof plug is provided on the process protrusion 11 .

[0047] Embodiment 2

[0048] The difference between the energy storage device in the second embodiment and the first embodiment is that the current collecting disc portion 51 in the electrode lead-out structure 5 is manufactured separately, and the large diameter cylindrical portion 52, the small diameter cylindrical portion 53 and the curling edge 54 are formed integrally. The center of the current collecting disc portion 51 is a flat plate structure, and the large diameter cylindrical portion 52 is fixedly connected to the center of the current collecting disc portion 51 by laser welding; or the center of the current collecting disc portion 51 is provided with a circular hole that matches the large diameter cylindrical portion 52, and the large diameter cylindrical portion 52 is inserted into the circular hole at the center of the current collecting disc portion 51, and then fixedly connected to the center of the current collecting disc portion 51 by laser welding.

[0049] Preferably, the material of the current collecting disk portion 51 is copper, and the material of the large diameter cylindrical portion 52 , the small diameter cylindrical portion 53 and the curling edge 54 is aluminum.

[0050] Embodiment 3

[0051] Figure 8 The specific manufacturing process of the energy storage device of the present invention is given. The manufacturing process of the energy storage device of the present invention includes the following steps:

[0052] Step 1: Preparation of electrode lead structure 5;

[0053] Step 2: welding the lower surface of the current collecting disc portion 51 of the electrode lead-out structure 5 to the upper surface of the battery cell 2;

[0054] Step 3: The cover plate 3 is mounted on the large diameter cylindrical portion of the electrode lead-out structure 5 through its central opening; and the insulating seal 4 is installed between the large diameter cylindrical portion 52 and the central opening of the cover plate 3; or the insulating seal 4 is formed by injection molding;

[0055] Step 4, curling the curling edge 54 of the electrode lead-out structure 5 so that it abuts against the upper surface of the insulating seal 4;

[0056] Step five: put the assembly of the battery cell 2 , the electrode and the cover plate 3 into the housing 1 , and connect the cover plate 3 to the upper opening of the housing 1 .

[0057] Preferably, in step one, the electrode lead-out structure 5 is formed in one piece. First, a blank is prepared and a semi-finished product having a current collecting disk portion 51 and a cylindrical portion is obtained by stamping. Then, a large-diameter cylindrical portion 52, a small-diameter cylindrical portion 53 and a curled edge 54 are formed by milling, and a through hole 56 is formed on the current collecting disk portion 51.

[0058] Alternatively, in step one, the collecting disc portion 51 is formed by stamping a copper billet, and the large diameter cylindrical portion 52, the small diameter cylindrical portion 53 and the curled edge 54 are formed by milling an aluminum billet, and then the upper surface of the collecting disc portion 51 and the lower surface of the large diameter cylindrical portion 52 are fixedly connected together by laser welding.

[0059] Alternatively, in step one, the current collecting disc portion 51 is formed by stamping a copper billet, and a circular hole matching the large diameter cylindrical portion 52 is formed in the center of the current collecting disc portion 51, and the large diameter cylindrical portion 52, the small diameter cylindrical portion 53 and the curled edge 54 are milled from an aluminum billet, and then the bottom end of the large diameter cylindrical portion 52 is inserted into the circular hole in the center of the current collecting disc portion 51, and the current collecting disc portion 51 is welded to the circular hole in the center of the current collecting disc portion 51 by laser welding.

[0060] In step three, the welding between the lower surface of the current collector 6 and the upper surface of the battery cell 2 is laser welding.

[0061] In step 4, the material for injection molding is selected from one of polypropylene, polystyrene, polycarbonate, and nylon.

[0062] In step five, before placing the assembly of the battery cell 2, the electrode and the cover plate 3 into the shell 1, the shell 1 is pre-heated and expanded before assembly, and the heating temperature is between 150 and 200 degrees Celsius; the cover plate 3 is kept flush with the upper end opening of the shell 1, and the cover plate 3 and the shell 1 are connected together by laser welding, with a welding penetration of 0.5 to 1.2 mm and a spot overlap rate of 60 to 90%.

[0063] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An energy storage device, comprising a shell (1), a battery cell (2), a cover plate (3), an insulating seal (4) and an electrode lead-out structure (5), wherein the shell (1) is a barrel-shaped structure with one end open, the battery cell (2) is arranged in the shell (1), and the cover plate (3) is fixedly connected to the open end of the shell (1); an opening is arranged in the center of the cover plate (3), the electrode lead-out structure (5) is connected to the battery cell (2) and extends out from the opening in the center of the cover plate (3), and the insulating seal (4) is arranged between the electrode lead-out structure (5) and the opening in the center of the cover plate (3), and is used to insulate the electrode lead-out structure (5) and the cover plate (3), and to seal the opening in the center of the cover plate (3); Features: The electrode lead-out structure (5) is a directly connected inner rolled sealed electrode lead-out structure (5), and the electrode lead-out structure (5) comprises a current collecting disc portion (51), a large diameter cylindrical portion (52), a small diameter cylindrical portion (53), a curling edge (54), a curling edge groove (55), and a through hole (56); the current collecting disc portion (51) is in the shape of a disc and is used to collect the current of the battery cell 2; a large diameter cylindrical portion (52) is arranged at the central position of the current collecting disc portion (51); a small diameter cylindrical portion (53) is arranged at the center of the top of the large diameter cylindrical portion (52), and the large diameter cylindrical portion (52) and the small diameter cylindrical portion (53) are arranged coaxially; a curling edge (54) surrounding the small diameter cylindrical portion (53) is arranged at the outer ring of the top of the large diameter cylindrical portion (52); a curling edge groove (55) is arranged between the curling edge (54) and the small diameter cylindrical portion (53); The curling edge (54) is used to press against the upper surface of the insulating seal (4) of the energy storage device after being rolled up, so as to apply pressure to the insulating seal (4) and ensure the sealing effect of the insulating seal (4); The large diameter cylindrical portion (52) and the small diameter cylindrical portion (53) together constitute the electrode of the energy storage device.

2. An energy storage device according to claim 1, characterized in that: The collecting disc portion (51), the large diameter cylindrical portion (52), the small diameter cylindrical portion (53) and the curling edge (54) are integrally formed.

3. An energy storage device according to claim 1, characterized in that: The current collecting disc portion (51) is manufactured separately, and the large diameter cylindrical portion (52), the small diameter cylindrical portion (53) and the curling edge (54) are formed integrally; the large diameter cylindrical portion (52) is fixedly connected to the central position of the current collecting disc portion (51) by laser welding.

4. An energy storage device according to claim 3, characterized in that: A circular hole matching the large diameter cylindrical part (52) is provided at the central position of the current collecting disc part (51); the large diameter cylindrical part (52) is inserted into the circular hole at the central position of the current collecting disc part (51) and then fixedly connected to the central position of the current collecting disc part (51) by laser welding.

5. An energy storage device according to claim 3 or 4, characterized in that: The material of the current collecting disc portion (51) is copper, and the material of the large diameter cylindrical portion (52), the small diameter cylindrical portion (53) and the curling edge (54) is aluminum.

6. An energy storage device according to claim 1, characterized in that: In the initial state before curling, the outer diameter of the small diameter cylindrical portion (53) is smaller than the outer diameter of the large diameter cylindrical portion (52), the outer diameter of the curling edge (54) is larger than the outer diameter of the large diameter cylindrical portion (52), the inner diameter of the curling edge (54) is smaller than the outer diameter of the large diameter cylindrical portion (52), and the inner diameter of the curling edge (54) is larger than the outer diameter of the small diameter cylindrical portion (53); and the height of the curling edge (54) is larger than the height of the small diameter cylindrical portion (53).

7. A manufacturing process for the energy storage device according to claim 1, characterized in that: The steps include: Step 1, preparation of electrode lead structure (5); Step 2: welding the lower surface of the current collecting disc portion (51) of the electrode lead-out structure (5) to the upper surface of the battery core (2); Step 3: The cover plate (3) is mounted on the large diameter cylindrical portion of the electrode lead-out structure (5) through its central opening; and the insulating seal (4) is installed between the large diameter cylindrical portion (52) and the central opening of the cover plate (3); or the insulating seal (4) is formed by injection molding; Step 4, curling the curling edge (54) of the electrode lead-out structure (5) so that it abuts against the upper surface of the insulating seal (4); Step five: Place the assembly of the battery cell (2), the electrode and the cover plate (3) into the housing (1), and connect the cover plate (3) to the upper opening of the housing (1).

8. A manufacturing process according to claim 7, characterized in that: In step one, the electrode lead-out structure (5) is formed in one piece. First, a blank is prepared, and a semi-finished product having a current collecting disc portion (51) and a cylindrical portion is obtained by stamping. Then, a large-diameter cylindrical portion (52), a small-diameter cylindrical portion (53) and a curling edge (54) are formed by milling, and a through hole (56) is formed on the current collecting disc portion (51).

9. A manufacturing process according to claim 7, characterized in that: In step three, the welding between the lower surface of the current collector (6) and the upper surface of the battery cell (2) is laser welding; in step four, the injection molding material is selected from one of polypropylene, polystyrene, polycarbonate, and nylon.

10. A manufacturing process according to claim 7, characterized in that: In step five, before placing the assembly of the battery cell (2), the electrode and the cover plate (3) into the shell (1), the shell (1) is preheated to expand before assembly, and the heating temperature is between 150°C and 200°C; the upper openings of the cover plate (3) and the shell (1) are kept flush, and the cover plate (3) and the shell (1) are connected together by laser welding, with a welding penetration of 0.5 to 1.2 mm and a spot overlap rate of 60 to 90%.

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