CN114204171A

CN114204171A - Preparation method of battery and cylindrical lithium battery

Info

Publication number: CN114204171A
Application number: CN202111405992.2A
Authority: CN
Inventors: 赵俊峰; 佘奕奕
Original assignee: Shenzhen Bak Power Battery Co Ltd
Current assignee: Shenzhen Bak Power Battery Co Ltd
Priority date: 2021-11-24
Filing date: 2021-11-24
Publication date: 2022-03-18

Abstract

The invention belongs to the technical field of battery preparation, and particularly relates to a preparation method of a battery and a cylindrical lithium battery. The preparation method of the battery comprises the following steps: preparing a shell, stretching the shell into a cylindrical shape, forming an accommodating cavity on the shell, wherein the shell is provided with a closed end and an open end opposite to the closed end, and the end surface of the closed end is provided with an electrode leading-out hole communicated with the accommodating cavity; leading out an electrode, namely putting the battery cell into the accommodating cavity, covering and sealing an electrode leading-out hole by using the positive electrode end cover, leading out the positive electrode of the battery cell to the positive electrode end cover through the electrode leading-out hole, and leading out the negative electrode of the battery cell to the shell; and encapsulating the battery, injecting electrolyte into the accommodating cavity through the opening, and connecting the explosion-proof sheet with the shell at the opening end in a sealing manner. The invention can properly increase the area of the explosion-proof sheet, improve the pressure relief opening and finally improve the safety of the battery.

Description

Preparation method of battery and cylindrical lithium battery

Technical Field

The invention belongs to the technical field of battery preparation, and particularly relates to a preparation method of a battery and a cylindrical lithium battery.

Background

At present, with the development of mobile electric equipment and energy storage products, lithium batteries are gradually accepted by the market as a representative of high energy density batteries, and the common appearance of lithium ion batteries mainly comprises a cylindrical shape and a square shape.

The manufacturing process of the traditional cylindrical lithium battery is as follows: and manufacturing a battery roll core, arranging a positive current collecting plate and a negative current collecting plate at two ends of the battery respectively, integrally placing the battery roll core into the shell, leading the positive electrode of the battery roll core out to a positive electrode end cover positioned at one end of the shell, welding the positive electrode end cover with the positive current collecting plate, and arranging an explosion-proof sheet at the positive electrode end cover. And the negative end cover positioned at the other end of the shell leads the negative electrode of the battery roll core out to the shell and is connected with the shell in a welding mode.

However, in the manufacturing method of the battery, the explosion-proof sheet and the positive end cover are arranged at the same end of the shell, so that the effective pressure relief area of the explosion-proof sheet is not too large, and the safety of the battery is reduced.

Disclosure of Invention

An object of the embodiments of the present application is to provide a method for manufacturing a battery, which aims to solve the problem of how to improve the safety of the battery.

In order to achieve the purpose, the technical scheme adopted by the application is as follows: provided is a method for manufacturing a battery, which includes the steps of:

preparing a shell, stretching the shell into a cylindrical shape, forming an accommodating cavity on the shell, wherein the shell is provided with a closed end and an open end opposite to the closed end, and an electrode leading-out hole communicated with the accommodating cavity is formed in the end surface of the closed end;

leading out an electrode, namely putting a battery cell into the accommodating cavity, covering and sealing the electrode leading-out hole by using an anode end cover, leading out the anode of the battery cell to the anode end cover through the electrode leading-out hole, and leading out the cathode of the battery cell to the shell;

and encapsulating the battery, injecting electrolyte into the accommodating cavity through the opening, and connecting the explosion-proof sheet to the shell at the opening end in a sealing manner.

In one embodiment, the battery core comprises a battery roll core, a positive current collecting plate connected with the positive end of the battery roll core and an electric post connected with the positive current collecting plate; the step of extracting the electrodes further comprises an electrical post: pressing the positive current collecting plate on the battery winding core and performing laser welding; the electric connecting column is ultrasonically welded with the positive collector plate; the part of the electric connection column exposed to the shell is electrically connected with the positive end cover and forms a positive electrode together.

In one embodiment, the battery cell further comprises a positive electrode insulation sheet, and the positive electrode insulation sheet and the positive electrode current collecting plate are stacked and used for blocking the electrical contact between the positive electrode current collecting plate and the casing.

In one embodiment, the step of extracting the electrode further comprises preparing an ultrasonic welder to ultrasonically and torsionally weld the positive end cap to the electrical connector post.

In one embodiment, the positive end cover is fixed downwards, and an ultrasonic head of the ultrasonic welding machine extends into the accommodating cavity and abuts against the positive current collecting plate.

In one embodiment, the battery core further comprises an anode current collecting plate, and the step of leading out the electrode further comprises the step of pressing the anode current collecting plate against the battery roll core and leading out the anode of the battery roll core from the side edge of the shell to the shell.

In one embodiment, the anode current collector plate is resistance welded or ultrasonically welded to the casing to electrically connect the anode exiting the battery roll core to the casing.

In one embodiment, the edges of the anode current collecting plate and the explosion-proof sheet are provided with flanges, and the flanges of the explosion-proof sheet abut against the flanges of the anode current collecting plate towards the inner wall of the accommodating cavity; and the step of packaging the battery further comprises the step of arranging a sealing ring in the flanging of the explosion-proof sheet, and curling the edge of the opening end inwards and pressing the sealing ring.

In one embodiment, a plurality of nicks are formed on the outer surface of the explosion-proof sheet, and the nicks are radially arranged.

Another aim of this application still lies in providing a cylindrical lithium cell, and it is formed by the preparation method preparation of above-mentioned battery, cylindrical lithium cell including have the holding chamber the shell, set up in electric core and the connection of holding intracavity the anodal end cover of shell, the shell still have the blind end and with the open end that the blind end set up relatively, the hole is drawn forth to the electrode is seted up to the blind end, anodal end cover is located the blind end and draws forth hole electric connection electric core through the electrode, the open end is provided with the explosion-proof piece, explosion-proof piece sealing connection the shell.

The beneficial effect of this application lies in: the positive end cover is fixed at the closed end of the shell, and the groove rolling treatment is not needed on the shell, namely, the inner wall of the accommodating cavity at the closed end does not bulge inwards and curl to form a groove rolling for fixing the positive end cover, so that metal powder, such as nickel powder, on the inner wall of the accommodating cavity is prevented from falling off, and the short circuit of a battery winding core is avoided. And install anodal end cover and explosion-proof piece respectively in the blind end and the open end of shell to avoided the installation influence of anodal end cover to the explosion-proof piece, made the installation space unrestricted of explosion-proof piece, and then can suitably increase the area of explosion-proof piece, improved the pressure release opening, finally improved the security of battery.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or exemplary technical descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a flowchart of a method for manufacturing a battery provided in an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of a cylindrical lithium battery provided in accordance with another embodiment of the present application;

fig. 3 is a partial enlarged view at a of fig. 2;

FIG. 4 is a schematic diagram of a cylindrical lithium battery and an ultrasonic head according to another embodiment of the present application;

fig. 5 is a schematic structural diagram of an explosion-proof plate according to still another embodiment of the present application.

Wherein, in the figures, the respective reference numerals:

100. an electric core; 101. a positive end cap; 102. an electrical connector; 103. an insulating washer; 104. an anode insulating sheet; 105. a positive collector plate; 106. a battery roll core; 107. a negative current collector; 109. a seal ring; 111. an accommodating cavity; 30. a housing; 31. an open end; 32. a closed end; 16. an explosion-proof sheet; 161. an explosion-proof body; 162. a hemming ring; 163. a second counterbore; 164. a first counterbore; 165. a third counterbore; 166. scoring;

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element. The terms "upper", "lower", "left", "right", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and operate, and thus are not to be construed as limiting the present application, and the specific meanings of the above terms may be understood by those skilled in the art according to specific situations. The terms "first", "second" and "first" are used merely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "plurality" is two or more unless specifically limited otherwise.

Referring to fig. 1 and fig. 3, an embodiment of the present application provides a method for manufacturing a battery, which includes the following steps:

s1: preparing the housing 30, drawing the housing 30 into a cylindrical shape and the housing 30 having the receiving cavity 111, and optionally drawing a metal plate into the cylindrical housing 30 through a drawing process while forming the receiving cavity 111. Alternatively, the material of the metal plate may be a nickel-plated steel material. The housing 30 has a closed end 32 and an open end 31, that is, one end of the accommodating cavity 111 is closed, and the other end of the accommodating cavity 111 has an opening. The closed end 32 is provided with an electrode lead-out hole communicated with the accommodating cavity 111. Alternatively, the cross-sectional shape of the housing 30 is circular.

S2: an electrode is led out, the battery cell 100 is placed in the accommodating cavity 111, the positive electrode end cover 101 covers and seals the electrode lead-out hole, the positive electrode of the battery cell 100 is led out to the positive electrode end cover 101 through the electrode lead-out hole, and then the negative electrode of the battery cell 100 is led out to the housing 30; optionally, the positive end cap 101 is made of a conductive material and is disposed in an insulating manner from the housing 30.

S3: and encapsulating the battery, injecting electrolyte into the accommodating cavity 111 through the opening, and hermetically connecting the explosion-proof sheet 16 with the shell 30 at the opening end 31. Optionally, the battery core 100 is dried, and then the electrolyte is injected into the accommodating cavity 111 at the opening end 31, without forming an injection hole at the positive end cover 101, so that the processing and installation difficulty of the battery is reduced.

Optionally, the electrolyte includes a lithium battery and an organic solvent mixed with the lithium battery.

Referring to fig. 1 and 3, the positive end cap 101 is fixed to the closed end 32 of the casing 30 without performing a rolling groove process on the casing 30, that is, the inner wall of the accommodating cavity 111 at the closed end 32 does not protrude and curl inward to form a rolling groove for fixing the positive end cap 101, so that metal powder, such as nickel powder, on the inner wall of the accommodating cavity 111 is prevented from falling off, and short circuit of the battery cell winding core 106 is avoided. And install anodal end cover 101 and explosion-proof piece 16 in the blind end 32 and the open end 31 of shell 30 respectively to avoided anodal end cover 101 to explosion-proof piece 16's installation influence, made explosion-proof piece 16's installation space unrestricted, and then can suitably increase explosion-proof piece 16's area, improved the pressure release opening, finally improved the security of battery.

Optionally, the explosion-proof sheet 16 is provided as a separate component and disposed at the open end 31, so that the battery has an oversized pressure relief opening, and the ratio of the area of the oversized pressure relief opening to the cross-sectional area of the casing 30 is greater than 0.75, whereas the ratio of the pressure relief area of the explosion-proof area of the conventional battery cell 100 to the radial cross-sectional area of the casing 30 is less than 50%.

Referring to fig. 1 and 3, in one embodiment, the battery cell 100 includes a battery roll core 106, a positive current collecting plate 105 connected to a positive terminal of the battery roll core 106, and an electrical connector 102 connected to the positive current collecting plate 105. Alternatively, the cell jelly roll 106 is formed by winding a separator paper. The S2: the step of extracting the electrodes further comprises an electrical post 102: pressing the positive current collecting plate 105 to the battery winding core 106, and performing laser welding; the electric post 102 is ultrasonically welded with the positive current collecting plate 105; the portion of the electrical post 102 exposed to the housing 30 is electrically connected to the positive end cap 101 and collectively forms the positive electrode. It will be appreciated that the outer surface of the housing 30 forms the negative electrode opposite the positive electrode.

Referring to fig. 1 and 3, alternatively, one end of the electric post 102 is integrally formed with the positive current collecting plate 105 through a stamping process, or one end of the electric post 102 is laser-welded to the positive current collecting plate 105; the other end of the electric post 102 exposed to the housing is ultrasonically welded with the positive end cover 101 through the electrode lead-out hole, and the electric post 102 and the positive end cover 101 together form a positive electrode. Alternatively, the ultrasonic welding may effectively reduce the internal resistance of the battery.

Optionally, the electrical post 102 is integrally formed with the positive end cap 101.

Referring to fig. 1 and fig. 3, in an embodiment, the battery cell 100 further includes a positive insulation sheet 104, and the positive insulation sheet 104 and the positive current collecting plate 105 are stacked and used for blocking an electrical contact between the positive current collecting plate 105 and the casing 30.

Optionally, the positive insulation sheet 104, the positive current collecting plate 105 and the battery roll core 106 are fixed by high-temperature adhesive paper, and then are placed into the accommodating cavity 111. The positive insulator sheet 104 may also provide insulation between the electrical post 102 and the outer casing 30.

Referring to fig. 1 and 3, in one embodiment, the step S2: the step of leading out the electrode further comprises the step of preparing an ultrasonic welding machine, and ultrasonically and torsionally welding the positive end cover 101 to the electric connection column 102.

Alternatively, the ultrasonic welding machine applies ultrasonic vibration to the positive electrode end cap 101 and the electric post 102, so that the electric post 102 and the positive electrode end cap 101 are welded together by ultrasonic torsional welding.

It can be understood that the ultrasonic torsional welding can fully weld the positive end cover 101 and the electric post 102, the electric connection area is increased, the resistance between the positive end cover 101 and the electric post 102 is reduced, and the connection reliability is improved.

Referring to fig. 4, in an embodiment, the positive end cap 101 is fixed downward, the ultrasonic head 20 of the ultrasonic welding machine extends into the receiving cavity 111 and abuts against the positive current collecting plate 105, and the electric post 102 is pressed toward the positive end cap 101, so that the electric post 102 is ultrasonically and torsionally welded to the positive end cap 101.

Referring to fig. 4, optionally, the positive end cover 101 is fixed on a fixture facing downward, the fixture supports the positive end cover 101, so that the positive end cover 101 can bear ultrasonic vibration, the ultrasonic head 20 of the ultrasonic welding machine is inserted into the accommodating cavity 111 from the open end 31 and abuts against the positive current collecting plate 105, and the ultrasonic vibration is applied to the positive current collecting plate 105, so that two ends of the electric post 102 are respectively welded to the positive end cover 101 and the positive current collecting plate 105 by ultrasonic torsion, the internal resistance of the battery is reduced, and the connection reliability is improved.

Referring to fig. 1 and fig. 3, in an embodiment, the battery cell 100 further includes an anode current collecting plate 107, and the step of extracting the electrode further includes pressing the anode current collecting plate 107 against the battery roll core 106 and extracting the anode of the battery roll core 106 from the side edge of the casing 30 to the casing 30.

Alternatively, laser welding is performed between anode current collecting plate 107 and the inner wall of accommodation chamber 111, thereby improving the stability of connection between anode current collecting plate 107 and case 30, and increasing the contact area between anode current collecting plate 107 and case 30, and reducing the internal resistance.

In one embodiment, the edges of the anode current collecting plate 107 and the explosion-proof sheet 16 are both flanged, and the flange of the explosion-proof sheet 16 abuts against the flange of the anode current collecting plate 107 towards the inner wall of the accommodating cavity 111; the step of packaging the battery further comprises the step of arranging a sealing ring 109 in the flanging of the explosion-proof sheet 16, and the edge of the opening end 31 is inwards punched and curled and tightly presses the sealing ring 109.

Optionally, the sealing ring 109 is an O-ring, the sealing ring 109 is first treated by dipping, and then the sealing ring 109 is disposed at the flanging of the explosion-proof sheet 16.

Optionally, the multi-layer flanging arrangement can improve the sealing performance of the opening end 31 and can meet the pressure relief requirement under extreme conditions.

Referring to fig. 5, in one embodiment, a plurality of notches 166 are formed on the outer surface of the explosion-proof plate 16, and each notch 166 is radially disposed.

In one embodiment, a first counter bore 164 and a second counter bore 163 are respectively formed at two ends of the score 166, and a center line of the score 166 passes through a center of the first counter bore 164 and a center of the second counter bore 163.

Referring to fig. 5, optionally, the explosion-proof sheet 16 includes an explosion-proof body 161 and a hemming ring 162 flanged on the edge of the explosion-proof body 161. Score 166 all sets up along the radial direction of explosion-proof body 161, can make score 166 begin to break from being close to explosion-proof body 161 centre of a circle position when the internal pressure of holding chamber 111 is too big for fan-shaped rupture district between the adjacent score 166 outwards breaks along explosion-proof body 161 edge direction of centre of a circle point direction of explosion-proof body 161 and opens, thereby can not produce the piece, avoids the piece that produces to cause external line short circuit and bodily injury.

Referring to fig. 5, optionally, the explosion-proof body 161 has an inner end surface located in the accommodating cavity 111 and an outer end surface opposite to the inner end surface. Score 166 opens at the outer end face. And a first counterbore 164 and a second counterbore 163 are respectively arranged at two ends of each notch 166. The first counterbore 164 is disposed proximate the center of the explosion proof body 161 and the second counterbore 163 is disposed proximate the edge of the explosion proof body 161. The center of the first counterbore 164 and the center of the second counterbore 163 corresponding to each notch 166 are located on the center line of the notch 166. The first counter bore 164 and the second counter bore 163 are respectively arranged at the starting end and the terminating end of each score 166, so that the fracture of the score 166 can be facilitated, and the outward fracture and opening of the fan-shaped fracture area can be facilitated.

Referring to fig. 5, optionally, a third counterbore 165 is formed in the center of the outer end surface. Each first counterbore 164 is disposed circumferentially about the third counterbore 165. The third counter bore 165 is formed in the center of the outer end face, so that the notch 166 can be further broken, and the fan-shaped broken area can be further broken and opened outwards, and the generation of fragments is avoided.

Referring to fig. 1 and 3, in one embodiment, the step of leading out the electrode further includes applying glue to the closed end 32 along the circumference of the electrode lead-out hole, gluing an insulating gasket 103 to the electrode lead-out hole, applying glue to the insulating gasket 103, and gluing the insulating gasket 103 to the positive end cap 101.

Optionally, the insulating gasket 103 is a ceramic insulating gasket 103, and the housing 30 and the positive end cap 101 are respectively glued to two side surfaces of the ceramic insulating gasket 103, so as to seal the electrode lead-out hole and enable the insulating arrangement between the positive end cap 101 and the housing 30.

The invention also provides a cylindrical lithium battery which is manufactured by the preparation method of the battery.

Referring to fig. 1 and fig. 3, optionally, the cylindrical lithium battery includes a casing 30 having an accommodating cavity 111, a battery cell 100 disposed in the accommodating cavity 111, and a positive end cap 101 connected to the casing 30, where the casing 30 further has a closed end 32 provided with an electrode lead-out hole and an open end 31 disposed opposite to the closed end 32, the positive end cap 101 is located at the closed end 32 and electrically connected to the battery cell 100, the open end 31 is provided with an explosion-proof sheet 16, and the explosion-proof sheet 16 is located at the open end 31 and hermetically connected to the casing 30.

The above are merely alternative embodiments of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement or the like made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A preparation method of a battery is characterized by comprising the following steps:

2. The method of manufacturing a battery according to claim 1, wherein: the battery core comprises a battery roll core, a positive current collecting plate connected with the positive end of the battery roll core and an electric post connected with the positive current collecting plate; the step of extracting the electrodes further comprises an electrical post: pressing the positive current collecting plate on the battery winding core and performing laser welding; the electric connecting column is ultrasonically welded with the positive collector plate; the part of the electric connection column exposed to the shell is electrically connected with the positive end cover and forms a positive electrode together.

3. The method of manufacturing a battery according to claim 2, wherein: the battery cell further comprises a positive electrode insulation sheet, and the positive electrode insulation sheet is stacked with the positive electrode collector plate and used for blocking the positive electrode collector plate and the electric contact of the shell.

4. The method of manufacturing a battery according to claim 2, wherein: and the step of leading out the electrode further comprises the step of preparing an ultrasonic welding machine, and welding the electric connecting column with the positive end cover through ultrasonic torsion.

5. The method of manufacturing a battery according to claim 4, wherein: and fixing the anode end cover downwards, wherein an ultrasonic head of the ultrasonic welding machine extends into the accommodating cavity and abuts against the anode collector plate.

6. The method for producing a battery according to any one of claims 1 to 5, wherein: the battery core further comprises a negative current collector plate, and the step of leading out the electrodes further comprises the step of pressing the negative current collector plate to the battery roll core and leading out the negative pole of the battery roll core to the shell from the side edge of the shell.

7. The method of manufacturing a battery according to claim 6, wherein: and the negative current collecting plate is subjected to resistance welding or ultrasonic welding on the shell so as to electrically connect the negative electrode which leads out the battery roll core to the shell.

8. The method of manufacturing a battery according to claim 6, wherein: arranging flanges at the edges of the negative current collector plate and the explosion-proof piece, wherein the flanges of the explosion-proof piece are abutted against the flanges of the negative current collector plate towards the inner wall of the accommodating cavity; and the step of packaging the battery further comprises the step of arranging a sealing ring in the flanging of the explosion-proof sheet, and curling the edge of the opening end inwards and pressing the sealing ring.

9. The method for producing a battery according to any one of claims 1 to 5, wherein: a plurality of nicks are arranged on the outer surface of the explosion-proof sheet, and the nicks are arranged in a radial mode.

10. The cylindrical lithium battery is characterized by comprising a shell with a containing cavity, an electric core arranged in the containing cavity and an anode end cover connected with the shell, wherein the shell is further provided with a closed end and an open end opposite to the closed end, the closed end is provided with an electrode leading-out hole, the anode end cover is positioned at the closed end and is electrically connected with the electric core through the electrode leading-out hole, the open end is provided with an explosion-proof sheet, and the explosion-proof sheet is hermetically connected with the shell.