A battery and its assembly process

Abstract

The present invention relates to the field of lithium battery assembly technology, and discloses a battery and its assembly process, including: a cell assembly, wherein the two ends of the cell assembly are respectively provided with a positive electrode and a negative electrode; a shell, wherein the two ends of the shell are respectively formed into an open end and a rolled edge stop end, the cell assembly extends into the shell from the open end, and the negative end is limited and stopped at the rolled edge stop end; a negative electrode connecting piece, which covers the open end, is a conductive piece and is electrically connected to the negative electrode and the shell portion at the open end through laser welding points. Through the technical solution of the present invention, the positive and negative electrodes of the battery can be located on the same side, which facilitates the design and welding of the external module bus, and at the same time can increase the rate performance of the cell assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ion battery assembly, in particular to a battery and an assembly process thereof. Background Art

[0002] As lithium-ion battery technology matures, lithium-ion batteries are widely used as power batteries in the field of electric vehicles. The structural components of lithium-ion batteries are also an important part of lithium-ion power batteries. They not only provide protection for the safety and reliability of lithium-ion batteries, but also take into account the connection between the internal chemical system of lithium-ion batteries and external modules. With the development of the industry, the demand for rapid charging and discharging of batteries is getting higher and higher, and the requirements for the overcurrent capacity and safety capabilities of lithium batteries are also getting higher and higher. Therefore, high-rate performance of structural components is the general trend. However, in the manufacturing process of existing lithium-ion batteries, the negative electrode of the battery cell and the shell are connected by resistance welding. The contact area of the resistance welding between the battery cell and the shell is too small, which affects the rate performance of the battery cell. At the same time, the positive and negative electrodes of the battery are located at opposite ends of the shell, which is not conducive to the design and welding of the external module bus. Summary of the Invention

[0003] The present invention aims to provide a battery and an assembly process thereof, which can locate the positive and negative poles of the battery on the same side, facilitate the design and welding of the external module bus, and at the same time increase the rate performance of the battery cell assembly.

[0004] To achieve the above-mentioned purpose, the present invention provides a battery, comprising: a battery cell assembly, wherein a positive electrode and a negative electrode are respectively provided at both ends of the battery cell assembly; a shell, wherein the two ends of the shell are respectively formed as an open end and a rolled edge stop end, the battery cell assembly extends into the shell from the open end and the negative end is limited and stopped at the rolled edge stop end; a negative electrode connecting plate, which covers the open end, the negative electrode connecting plate is a conductive plate and is electrically connected to the negative electrode and the shell part at the open end through laser welding points.

[0005] Furthermore, the open end is provided with a lip that abuts against the negative electrode, and the edge of the negative electrode connecting piece is bent to form a step that fits with the lip.

[0006] Furthermore, the battery cell assembly includes a positive electrode cover fixed on the positive electrode, and a conductive sheet electrically connected to the battery cell is provided on the positive electrode cover; the battery includes an insulating gasket arranged between the positive electrode cover and the rolled edge stop end, and the insulating gasket is provided with a through hole for the conductive sheet to pass through.

[0007] Furthermore, the battery includes a negative electrode cover plate attached to the surface of the negative electrode connecting piece, and the negative electrode cover plate seals the open end.

[0008] Furthermore, the battery includes a seal, the positive electrode of the battery cell assembly is provided with an injection hole, and the seal is fixed and sealed to the surface of the injection hole; the battery cell assembly and the shell are both cylindrical, and the material of the negative electrode connecting piece includes any one of copper, iron, and aluminum.

[0009] To achieve the above-mentioned purpose, the present invention also provides a battery assembly process for assembling the above-mentioned battery, and the battery assembly process includes: inserting the battery cell assembly into the shell from the open end, and making the positive limit of the battery cell assembly located at the roll stop end, and the negative pole of the battery cell assembly located at the open end; attaching the negative electrode connecting piece to the negative electrode and performing laser welding; covering the negative electrode connecting piece on the open end and performing laser welding.

[0010] Furthermore, the battery assembly process also includes: before covering the negative electrode connecting piece on the open end and performing laser welding, the open end is rolled to form a lip edge that is against the four sides of the negative electrode at the open end; and the edge of the negative electrode connecting piece is bent to form a step that fits with the lip edge.

[0011] Furthermore, before the step of inserting the battery cell assembly into the shell from the open end, the steps are further included: fitting the positive electrode cover plate onto the positive electrode and performing laser welding to form a battery cell assembly; inserting the insulating gasket into the shell from the open end and fitting it with the rolled edge stop end, so that the conductive sheet on the positive electrode cover plate passes through the insulating gasket and is exposed to the shell.

[0012] Furthermore, after the step of inserting the battery cell assembly into the shell from the open end of the shell, the method further includes the steps of: laser welding the positive electrode cover plate and the rolled edge stop end and sealing the rolled edge stop end.

[0013] Furthermore, the battery assembly process also includes the steps of: injecting electrolyte into the injection hole of the positive electrode; covering the injection hole with a sealing member; and laser welding the sealing member to the battery cell assembly.

[0014] Compared with the prior art, the battery and its assembly process described in the present invention have the following advantages:

[0015] In the battery assembly process of the present invention, laser welding is performed on the negative electrode connector to the negative electrode of the battery cell assembly and the housing, thereby forming laser welds between the negative electrode and the negative electrode connector, and between the negative electrode connector and the housing. This, in turn, forms a negative electrode with a negative charge on the housing, ultimately locating the positive and negative electrodes of the battery at the same end, which is more conducive to the design and welding of external module busbars. At the same time, the laser welds can increase the contact area between the battery cell assembly, the negative electrode connector, and the housing, thereby improving the flow capacity from the negative electrode of the battery cell assembly to the housing and enhancing the rate performance of the battery cell assembly.

[0016] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 is a schematic diagram of the three-dimensional structure of a battery according to an embodiment of the present invention;

[0019] Figure 2 is a schematic diagram of an exploded structure of a battery according to an embodiment of the present invention;

[0020] Figure 3 is a schematic diagram of a partially exploded structure of a battery according to an embodiment of the present invention;

[0021] Figure 4 FIG. 1 is a schematic diagram of a partial cross-sectional structure of a battery according to an embodiment of the present invention.

[0022] Figure 5 is a flowchart of the steps of a battery assembly process according to one embodiment of the present invention;

[0023] Figure 6 is a flow chart of steps before step S2 according to an embodiment of the present invention;

[0024] Figure 7 FIG. 4 is a flow chart of further steps of a battery assembly process according to an embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 1 battery

[0027] 11 Battery cell assembly 12 Housing

[0028] 13 Negative electrode connector 14 Insulation washer

[0029] 15 negative electrode cover 16 seal

[0030] 111 positive electrode cover 112 battery cell

[0031] 113 conductive sheet 114 injection hole

[0032] 121 Open end 122 Piping stop end

[0033] 123 Lips

[0034] 131 steps DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0036] The directions or positional relationships indicated by “length”, “width”, “up”, “down”, “front”, “back”, “left”, “right”, “top”, “bottom”, “inside” and “outside” mentioned in the embodiments of the present invention are based on the directions or positional relationships shown in the accompanying drawings. They 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 direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0037] In addition, the terms "mounted," "connected," "connect," "fixed," etc. should be interpreted broadly. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0039] Figure 1 FIG. 1 is a schematic diagram of a three-dimensional structure of a battery according to an embodiment of the present invention. Figure 2 FIG. 1 is a schematic diagram of an exploded structure of a battery according to an embodiment of the present invention. Figure 3 FIG. 1 is a schematic diagram of a partially exploded structure of a battery according to an embodiment of the present invention. Figure 4 FIG. 1 is a schematic diagram of a partial cross-sectional structure of a battery according to an embodiment of the present invention. Figures 1-4 As shown, in an embodiment of the present invention, a battery 1 is provided, including: a cell assembly 11, wherein the two ends of the cell assembly 11 are respectively provided with a positive electrode and a negative electrode; a shell 12, wherein the two ends of the shell 12 are respectively formed as an open end 121 and a rolled edge stop end 122, the cell assembly 11 extends into the shell 12 from the open end 121 and the negative end is limited and stopped at the rolled edge stop end 122; a negative electrode connecting piece 13, which covers the open end 121, and the negative electrode connecting piece 13 is a conductive piece 113 and is electrically connected to the negative electrode and the shell 12 part of the open end 121 through laser welding points.

[0040] Since the two ends of the shell 12 are respectively an open end 121 and a rolled edge stop end 122, the battery cell assembly 11 can be extended into the shell 12 from the open end 121, so that the positive pole of the battery cell assembly 11 faces the rolled edge stop end 122 and the negative pole faces the open end 121, and the battery cell assembly 11 is limited under the action of the rolled edge stop end 122, and the negative pole is covered on the open end 121 by the negative electrode connecting piece 13, so that the surface of the negative electrode connecting piece 13 is fitted with the negative electrode, and laser welding is performed to form a laser welding point between the negative electrode and the negative electrode connecting piece 13. Since the negative electrode connecting piece 13 is a conductive piece 113, electrical conduction between the battery cell assembly 11 and the negative electrode connecting piece 13 can be achieved. The edge of the negative electrode connecting piece 13 is fitted with the inner wall of the open end 121 and laser welded, thereby forming a laser weld point between the negative electrode connecting piece 13 and the shell 12. Since electrical conduction is formed between the negative electrode connecting piece 13 and the battery cell assembly 11, electrical conduction can be formed between the negative electrode connecting piece 13 and the shell 12, thereby forming a negative electrode with negative charge in the shell 12, that is, the rolled edge stop end 122 is a negative electrode with negative charge, so that the positive and negative poles of the battery are located on the same side.

[0041] In an embodiment of the present invention, a through hole is provided in the middle of the rolled stop end 122, and the size of the through hole is smaller than the size of the battery cell assembly 11, so as to stop and limit the battery cell assembly 11. At the same time, the positive pole of the external module bus can be electrically connected to the positive pole of the battery cell assembly 11 under the action of the through hole, and then the negative pole of the external module bus can be electrically connected to the rolled stop end 122, so as to realize electrical conduction between the module bus and the battery 1. Compared with the battery in the prior art in which the positive and negative poles are located at both ends, the battery 1 of the present invention is more conducive to the design and welding of the external module bus.

[0042] In an embodiment of the present invention, the negative electrode of the battery cell assembly 11 is laser welded to the negative electrode connecting piece 13, and the negative electrode connecting piece 13 is laser welded to the shell 12 at the open end 121, so that a laser weld point can be formed between the negative electrode of the battery cell assembly 11 and the negative electrode connecting piece 13, and a laser weld point can be formed between the negative electrode connecting piece 13 and the shell 12. Compared with the resistance welding method in the prior art, the laser weld point of the present invention can make the contact area between the battery cell assembly 11, the negative electrode connecting piece 13 and the shell 12 larger, thereby improving the current flow capacity from the negative electrode of the battery cell assembly 11 to the shell 12, and improving the rate performance of the battery cell assembly 11.

[0043] In the embodiment of the present invention, the battery cell assembly 11 and the housing 12 are both cylindrical, and the negative electrode connecting piece 13 is made of any one of copper, iron, and aluminum.

[0044] In the embodiment of the present invention, the open end 121 is provided with a lip 123 that abuts against the negative electrode, and the edge of the negative electrode connecting piece 13 is bent to form a step 131 that fits with the lip 123 .

[0045] By providing a lip 123 at the open end 121 and bending the edge of the negative electrode connecting piece 13 to form a step 131 that fits the lip 123, when laser welding the negative electrode connecting piece 13 and the shell 12 portion at the open end 121, the step 131 fits on the lip 123 and forms a positioning function. In addition, the step 131 and the lip 123 can also be laser welded, thereby increasing the welding area between the negative electrode connecting piece 13 and the shell 12, which is more conducive to laser welding between the negative electrode connecting piece 13 and the shell 12.

[0046] In an embodiment of the present invention, the battery cell assembly 11 includes a positive electrode cover 111 fixed on the positive electrode, and a conductive sheet 113 electrically connected to the battery cell 112 is provided on the positive electrode cover 111; the battery 1 includes an insulating gasket 14 arranged between the positive electrode cover 111 and the rolled edge stop end 122, and the insulating gasket 14 is provided with a through hole for the conductive sheet 113 to pass through.

[0047] By setting the positive electrode cover 111 on the positive electrode of the battery cell 112 and setting a conductive sheet 113 electrically connected to the battery cell 112 on the positive electrode cover 111, electrical conduction between the positive electrode of the battery cell 112 and the conductive sheet 113 is achieved. When the external bus module needs to be electrically connected to the battery 1, the positive electrode of the external bus module can be welded to the conductive sheet 113, which is more conducive to welding the external bus module and the positive electrode of the battery 1.

[0048] By disposing an insulating gasket between the positive electrode cover plate 111 and the rolled edge stop end 122, the positive electrode of the cell assembly 11 is insulated from the housing 12 by the insulating gasket, preventing the positive electrode of the cell assembly 11 from contacting the housing 12 and causing a short circuit. A through hole is provided in the insulating gasket for the conductive sheet 113 to pass through, so that the conductive sheet 113 is exposed to the housing 12 through the through hole in the insulating gasket. That is, the conductive sheet 113 extends from the through hole in the middle of the rolled edge stop end 122, facilitating welding of the external busbar module to the conductive sheet 113.

[0049] It can be understood that the positive electrode cover plate 111 is filled with insulating material, so that the position where the positive electrode cover plate 111 and the rolled edge stop end 122 are welded is insulated from the position of the conductive sheet 113, thereby avoiding a short circuit between the positive electrode cover plate 111 and the shell 12 due to electrical conduction.

[0050] In an embodiment of the present invention, the positive electrode cover plate 111 and the battery cell 112 are laser welded, forming a laser weld point between the positive electrode cover plate 111 and the battery cell 112, thereby achieving electrical conduction between the positive electrode cover plate 111 and the positive electrode of the battery cell 112. The portion of the positive electrode cover plate 111 exposed outside the housing 12 is sealed and snapped into the through hole in the middle of the rolled edge stopper end 122, thereby securing the battery cell assembly 11 within the housing 12 and preventing the battery cell assembly 11 from shaking relative to the housing 12.

[0051] In an embodiment of the present invention, the battery 1 includes a negative electrode cover 15 attached to the surface of the negative electrode connecting piece 13, and the negative electrode cover 15 seals the open end 121. The negative electrode cover 15 is made of insulating materials such as plastic and rubber. The negative electrode cover 15 is attached to the surface of the negative electrode connecting piece 13, and the open end 121 is sealed by the negative electrode cover 15, so that the structural strength of the assembly between the battery cell assembly 11 and the shell 12 is further strengthened under the action of the negative electrode cover 15, and the battery cell assembly 11 is prevented from shaking in the shell 12. At the same time, the open end 121 can also be sealed under the action of the negative electrode cover 15 to prevent dust and debris from entering the shell 12 from the open end 121 and affecting the performance of the battery 1.

[0052] In an embodiment of the present invention, the battery 1 includes a sealing member 16. The positive electrode of the battery cell assembly 11 is provided with an injection hole 114. The sealing member 16 is fixed to and sealed on the surface of the injection hole 114. By providing the injection hole 114 on the positive electrode of the battery cell assembly 11, electrolyte can be injected into the interior of the battery cell assembly 11 through the injection hole 114 to decompose electrons. The sealing member 16 is provided to cover the surface of the injection hole 114 to seal the injection hole 114 and prevent the electrolyte from flowing out of the injection hole 114.

[0053] It can be understood that the sealing member 16 is an aluminum nail and is fixed to the surface of the liquid injection hole 114 by welding, thereby improving the sealing performance of the sealing member 16 in sealing the liquid injection hole 114 .

[0054] Figure 5 FIG. 1 is a flow chart of the steps of a battery assembly process according to an embodiment of the present invention. Figure 5 As shown, in an embodiment of the present invention, a battery assembly process is further provided for assembling the above-mentioned battery 1. The battery assembly process includes:

[0055] Step S1: inserting the battery cell assembly 11 into the housing 12 from the opening end 121 , with the positive end of the battery cell assembly 11 located at the rolling stop end 122 and the negative end of the battery cell assembly 11 located at the opening end 121 ;

[0056] Step S2: Laminating the negative electrode connecting piece 13 to the negative electrode and performing laser welding;

[0057] Step S3: Cover the negative electrode connecting piece 13 on the open end 121 and perform laser welding.

[0058] The battery cell assembly 11 is first inserted into the housing 12 from the open end 121, with the positive end of the battery cell assembly 11 located at the rolled edge stop end 122, and the negative end of the battery cell assembly 11 located at the open end 121, so that the battery cell assembly 11 is limited by the rolled edge stop end 122. Furthermore, the surface of the negative electrode connecting tab 13 is bonded to the negative electrode, and laser welding is performed to form a laser weld point between the negative electrode and the negative electrode connecting tab 13, thereby achieving electrical conduction between the battery cell assembly 11 and the negative electrode connecting tab 13. Finally, the negative electrode connecting piece 13 is covered on the open end 121 and laser welded, that is, the edge of the negative electrode connecting piece 13 is fitted with the inner wall of the open end 121 and laser welded, thereby forming a laser welding point between the negative electrode connecting piece 13 and the shell 12, realizing electrical conduction between the negative electrode connecting piece 13 and the shell 12, and then making the shell 12 form a negative electrode with negative charge, that is, making the rolled edge stop end 122 a negative electrode with negative charge.

[0059] The battery 1 obtained by the battery assembly process of the present invention is more conducive to the design and welding of the external module bus compared to the battery 1 in the prior art in which the positive and negative electrodes are located at both ends, and the laser welding point of the present invention can make the contact area between the battery cell assembly 11, the negative electrode connecting piece 13 and the shell 12 larger, thereby improving the flow capacity from the negative electrode of the battery cell assembly 11 to the shell 12 and improving the rate performance of the battery cell assembly 11.

[0060] In an embodiment of the present invention, before the step of covering the negative electrode connecting tab 13 on the open end 121 and performing laser welding, the following steps are further included:

[0061] Step S301 : rolling the open end 121 to form a lip 123 on the open end 121 to abut against the periphery of the negative electrode; and bending the edge of the negative electrode connecting piece 13 to form a step 131 that fits with the lip 123 .

[0062] Before the negative electrode connecting piece 13 is covered on the open end 121 and laser welded, the open end 121 is rolled and a lip 123 is formed at the open end 121 to abut against the negative electrode to limit the battery cell assembly 11. The edge of the negative electrode connecting piece 13 is bent out of the step 131 that fits the lip 123. Therefore, when the negative electrode connecting piece 13 and the shell 12 portion of the open end 121 are laser welded, the step 131 fits on the lip 123 and forms a positioning effect. In addition, the step 131 and the lip 123 can be laser welded, thereby increasing the welding area between the negative electrode connecting piece 13 and the shell 12, which is more conducive to laser welding between the negative electrode connecting piece 13 and the shell 12.

[0063] Figure 6 This is a flowchart of the steps before step S2 according to an embodiment of the present invention. Figure 6 As shown, in an embodiment of the present invention, before the step of inserting the battery cell assembly 11 into the housing 12 from the open end 121, the following steps are further included:

[0064] Step S201: attaching the positive electrode cover 111 to the positive electrode and performing laser welding to form a battery cell assembly 11;

[0065] Step S202 : insert the insulating gasket 14 into the housing 12 from the open end 121 and fit it with the rolled edge stop end 122 , so that the conductive sheet 113 on the positive electrode cover 111 passes through the insulating gasket 14 and is exposed outside the housing 12 .

[0066] Before inserting the cell assembly 11 into the housing 12 from the open end 121, the positive electrode cover 111 is first attached to the positive electrode of the cell 112 and laser welded to form the cell assembly 11. Since the positive electrode cover 111 is provided with a conductive sheet 113 electrically connected to the cell 112, electrical conduction between the positive electrode of the cell 112 and the conductive sheet 113 can be achieved. Then, the insulating gasket is inserted into the housing 12 from the open end 121 and attached to the rolled edge stopper end 122, so that the conductive sheet 113 on the positive electrode cover 111 passes through the insulating gasket 14 and is exposed to the housing 12. The positive electrode of the cell assembly 11 and the housing 12 are insulated by the insulating gasket, preventing the positive electrode of the cell assembly 11 from contacting the housing 12 and causing a short circuit. A through hole is opened on the insulating gasket for the conductive sheet 113 to pass through, so that the conductive sheet 113 is exposed to the shell 12 through the through hole on the insulating gasket. That is, the conductive sheet 113 extends from the through hole in the middle of the rolled edge stop end 122, which facilitates welding of the external bus module and the conductive sheet 113.

[0067] In an embodiment of the present invention, after the step of inserting the battery cell assembly 11 into the housing 12 from the open end 121 of the housing 12, the method further includes:

[0068] Step S11 : laser welding the positive electrode cover plate 111 and the rolled edge stopper end 122 and sealing the rolled edge stopper end 122 .

[0069] By laser welding the positive electrode cover 111 and the rolled edge stop end 122, the structural stability of the battery cell assembly 11 in the shell 12 can be further improved, and the battery cell assembly 11 can be prevented from shaking relative to the shell 12. At the same time, the through hole of the rolled edge stop end 122 is sealed by laser welding to prevent dust and debris from entering the shell 12 through the rolled edge stop end 122 and affecting the performance of the battery 1.

[0070] Figure 7 FIG. 1 is a flow chart of further steps of a battery assembly process according to an embodiment of the present invention. Figure 7 As shown, in an embodiment of the present invention, the battery assembly process further includes:

[0071] Step S4: injecting electrolyte into the injection hole 114 of the positive electrode;

[0072] Step S5: Cover the liquid injection hole 114 with the sealing member 16;

[0073] Step S6: laser welding the seal 16 and the battery cell assembly 11 .

[0074] Since the positive electrode of the battery cell assembly 11 is provided with an injection hole 114, electrolyte can be injected into the interior of the battery cell assembly 11 through the injection hole 114, so that the electrolyte can decompose electrons. Then, a sealing member 16 that can cover the surface of the injection hole 114 is provided to seal the injection hole 114 to prevent the electrolyte from flowing out of the injection hole 114. Finally, the sealing member 16 and the battery cell assembly 11 are laser welded to fix the sealing member 16 on the battery cell assembly 11, thereby improving the sealing performance of the sealing member 16 in sealing the injection hole 114.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A battery, characterized in that: include: A battery cell assembly (11), wherein two ends of the battery cell assembly (11) are respectively provided with a positive electrode and a negative electrode; A shell (12), wherein two ends of the shell (12) are respectively formed as an open end (121) and a rolled edge stop end (122); the battery cell assembly (11) extends into the shell (12) from the open end, and the positive end is limitedly stopped at the rolled edge stop end (122); A negative electrode connecting piece (13) covers the open end (121), the negative electrode connecting piece (13) being a conductive piece and electrically connecting the negative electrode and the shell portion of the open end (121) through laser welding points; wherein a through hole is provided in the middle of the rolled edge stop end (122); the battery cell assembly (11) comprises a positive electrode cover plate (111) fixed on the positive electrode; one end of the positive electrode cover plate (111) is welded to the positive electrode; the other end portion extends to the outside of the through hole of the rolled edge stop end (122) and is welded to the rolled edge stop end (122); a conductive sheet (113) electrically connected to the battery cell (112) is further provided on the positive electrode cover plate (111); one end of the conductive sheet (113) passes through the through hole of the rolled edge stop end (122) and is exposed to the outside of the housing (12); and the portion where the positive electrode cover plate (111) is welded to the rolled edge stop end (122) is insulated from the conductive sheet (113); The open end (121) is provided with a lip (123) that abuts against the negative electrode, and the edge of the negative electrode connecting piece (13) is bent to form a step (131) that fits the lip (123); The battery comprises an insulating washer (14) arranged between the positive electrode cover plate (111) and the rolled edge stop end (122), and the insulating washer (14) is provided with a through hole for the conductive sheet (113) to pass through.

2. The battery according to claim 1, characterized in that The battery comprises a negative electrode cover plate (15) attached to the surface of the negative electrode connecting piece (13), and the negative electrode cover plate (15) seals the open end (121).

3. The battery according to any one of claims 1 to 2, characterized in that: The battery comprises a sealing member (16), a positive electrode of the battery cell assembly (11) is provided with a liquid injection hole (114), and the sealing member (16) is fixed and sealed on the surface of the liquid injection hole (114); The battery core assembly (11) and the shell (12) are both cylindrical, and the material of the negative electrode connecting piece (13) includes any one of copper, iron, and aluminum.

4. A battery assembly process for assembling the battery according to any one of claims 1 to 3, characterized in that: The battery assembly process includes: Inserting the battery cell assembly (11) into the housing (12) from the opening end (121), with the positive end of the battery cell assembly (11) located at the rolling stop end (122), and the negative end of the battery cell assembly (11) located at the opening end (121); Laminating the negative electrode connecting piece (13) to the negative electrode and performing laser welding; The negative electrode connecting piece (13) is covered on the open end (121) and laser welded.

5. The battery assembly process according to claim 4, characterized in that: Before the step of covering the negative electrode connecting piece (13) on the open end (121) and performing laser welding, the method further includes: rolling the open end (121) to form a lip (123) on the open end (121) that abuts against the four sides of the negative electrode; and bending the edge of the negative electrode connecting piece (13) to form a step (131) that fits the lip (123).

6. The battery assembly process according to claim 4, characterized in that: Before the step of inserting the battery cell assembly (11) into the housing (12) from the open end (121), the method further comprises: Laminating a positive electrode cover plate (111) onto the positive electrode and performing laser welding to form a battery core assembly (11); The insulating gasket (14) is installed into the housing (12) from the open end (121) and is fitted with the rolled edge stop end (122), so that the conductive sheet (113) on the positive electrode cover plate (111) passes through the insulating gasket (14) and is exposed outside the housing (12).

7. The battery assembly process according to claim 6, characterized in that: After the step of inserting the battery cell assembly (11) into the housing (12) from the open end (121) of the housing (12), the method further includes: laser welding the positive electrode cover plate (111) and the rolled edge stop end (122) and sealing the rolled edge stop end (122).

8. The battery assembly process according to claim 4, characterized in that: The battery assembly process further includes: injecting electrolyte into the liquid injection hole (114) of the positive electrode; Covering the liquid injection hole (114) with a sealing member (16); The sealing member (16) and the battery core assembly (11) are laser welded.

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