Lithium battery and production method

Abstract

The application relates to the technical field of batteries, and provides a lithium battery and a production method, the lithium battery comprising a steel shell, a negative electrode current collector and an explosion-proof piece; the negative electrode current collector is located in the steel shell and close to the bottom of the steel shell, and is used for being connected with the end of a flattened winding core; the bottom of the steel shell is provided with an opening, the explosion-proof piece is arranged at the bottom of the steel shell, and the explosion-proof piece covers the opening; the explosion-proof piece is provided with explosion-proof notches; the negative electrode current collector is provided with a plurality of elastic sheets, the adjacent elastic sheets are separated, and the elastic sheets can be bounced towards the side away from the flattened winding core. The explosion-proof piece is arranged at the negative electrode end of the battery, the steel shell and the explosion-proof piece can be separately punched, and the stability is improved; the opening is arranged at the bottom of the steel shell, the negative electrode current collector, the explosion-proof piece and the opening are sequentially arranged, and the negative electrode current collector and the explosion-proof piece are arranged in the steel shell; when the pressure in the steel shell is too large, the pressure can be released in time, the explosion is effectively prevented, the explosion-proof performance is good, and the stability is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a lithium battery and a production method. BACKGROUND

[0002] Since the battery is sealed in a closed container, the battery may produce a gas swelling or even explosion phenomenon under improper use, therefore, the explosion-proof device is one of the important safety devices on the lithium battery.

[0003] At present, the mainstream large cylindrical battery sets the explosion-proof device on the positive cap structure, and the shell is used as the negative electrode, only a small part of small diameter steel shells are provided with the explosion-proof device by stamping and notching the shell bottom; from the market feedback, the explosion-proof pressure of the shell bottom stamping and notching is unstable, mainly because the notch is integrally stamped with the steel shell, the stamping stroke is greater than the height of the steel shell, so that the equipment is slightly unstable, and the pressure is unstable; and the stroke is difficult to control, especially for the steel shell with a very high height, the equipment stroke is larger, and the stability is poorer, and the function of protecting the battery cannot be achieved. SUMMARY

[0004] The present application provides a lithium battery and a production method, to solve the problem of poor stability of the explosion-proof device of the lithium battery in the prior art.

[0005] The present application provides a lithium battery, comprising: a steel shell, a negative current collector, and an explosion-proof piece; the negative current collector is located in the steel shell and close to the bottom of the steel shell, and is used for connecting with the end of the flattened roll core; the bottom of the steel shell is provided with an opening, the explosion-proof piece is arranged on the bottom of the steel shell, and the explosion-proof piece covers the opening, and the explosion-proof piece is provided with an explosion-proof notch; the negative current collector is provided with a plurality of elastic sheets, the adjacent elastic sheets are separated, and the elastic sheets can be popped up towards the side away from the flattened roll core.

[0006] According to the lithium battery provided by the present application, the opening and the side wall surface of the steel shell exist a connecting arm; the connecting arm comprises a connecting part and a supporting part, the connecting part is connected with the peripheral wall of the steel shell, the explosion-proof piece is arranged on the supporting part, and the vertical distance between the explosion-proof piece and the negative current collector is greater than or equal to the vertical distance between the connecting part and the negative current collector.

[0007] According to the lithium battery provided by the present application, the opening and the side wall surface of the steel shell exist a connecting arm; the connecting arm comprises a connecting part, a protruding part and a supporting part, the connecting part is connected with the peripheral wall of the steel shell, the protruding part is protruded towards the inside of the steel shell, the two sides of the protruding part are respectively transitionally connected with the connecting part and the supporting part, and the explosion-proof piece is arranged on the supporting part; the vertical distance between the explosion-proof piece and the negative current collector is greater than or equal to the vertical distance between the protruding part and the negative current collector.

[0008] According to the lithium battery provided by the application, the protective piece covers the bottom of the explosion-proof piece and is located outside the bottom of the steel shell.

[0009] According to the lithium battery provided by the application, the vertical distance between the protective piece and the negative current collector is less than or equal to the vertical distance between the connecting part and the negative current collector.

[0010] According to the lithium battery provided by the application, the protective piece is a non-metal piece.

[0011] According to the lithium battery provided by the application, the size of the explosion-proof notch is less than or equal to the size of the opening.

[0012] According to the lithium battery provided by the application, the explosion-proof notch is arranged on at least one side of the explosion-proof piece.

[0013] The application further provides a production method of the lithium battery, which comprises the following steps: welding the steel shell and the explosion-proof piece by laser welding, wherein the explosion-proof piece is located inside the steel shell, and the periphery of the explosion-proof piece is attached to the connecting arm; detecting the sealing property of the connection between the steel shell and the explosion-proof piece; welding the bottom of the steel shell and the negative current collector by penetration welding, wherein the negative current collector is close to the explosion-proof piece; welding the steel shell and the cover plate by laser welding to seal; detecting the sealing property of the connection between the steel shell and the cover plate; cleaning, drying and applying an anti-rust layer on the connection between the steel shell and the explosion-proof piece; and pasting the protective piece, wherein the protective piece covers the bottom of the explosion-proof piece and is located outside the bottom of the steel shell.

[0014] The lithium battery and the production method provided by the application can separate the steel shell and the explosion-proof piece for stamping, improve the stability, set the opening on the bottom of the steel shell, sequentially arrange the negative current collector, the explosion-proof piece and the opening, and arrange the negative current collector and the explosion-proof piece in the steel shell, so that the pressure in the steel shell can be released in time when the pressure is too large, the explosion is effectively prevented, the explosion-proof property is good, and the stability is high. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0016] Figure 1 It is an explosion diagram of the lithium battery provided by some embodiments of the application.

[0017] Figure 2 is a front view of a lithium battery provided by some embodiments of the present application;

[0018] Figure 3 is Figure 2 is a sectional view at A-A;

[0019] Figure 4 is Figure 3 is a partial enlarged view at A in

[0020] Figure 5 is a structural schematic view of a lithium battery provided by some embodiments of the present application Figure 4 is one of partial enlarged views at B in

[0021] Figure 6 is a structural schematic view of a lithium battery provided by some embodiments of the present application Figure 4 is the second of partial enlarged views at B in

[0022] Figure 7 is a structural schematic view of a negative current collector provided by some embodiments of the present application;

[0023] Figure 8 is a structural schematic view of an explosion-proof member provided by some embodiments of the present application.

[0024] Reference signs:

[0025] 1, steel shell; 11, opening; 12, connecting arm; 121, connecting portion; 122, protruding portion; 123, supporting portion; 2, explosion-proof member; 21, explosion-proof score; 3, protection member; 4, positive current collector; 5, flat-rolled core; 6, negative current collector; 61, spring sheet; 7, cover plate; 71, liquid injection hole; 8, rivet. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0027] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0028] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0029] The explosion-proof device is one of the important safety devices on the lithium battery. The battery in the related art is directly stamped with a notch at the bottom of the steel shell, and the stability is poor, and the battery cannot be protected.

[0030] To this end, the present application provides a lithium battery, the positive electrode is designed on the cover plate 7, the negative electrode is the shell bottom and the shell of the steel shell 1, and the explosion-proof piece 2 is arranged at the bottom of the steel shell 1. The explosion-proof piece 2, the steel shell 1 is separately stamped to ensure the stability of the explosion-proof pressure. At the same time, the explosion-proof piece 2 is welded with the shell bottom to ensure the sealing of the battery.

[0031] The lithium battery and the production method of the present application are described below. Figures 1-8 The lithium battery and the production method of the present application are described below.

[0032] As shown in Figure 1 , 2 and 3, the lithium battery provided by the present application comprises: a steel shell 1, a negative electrode current collector 6 and an explosion-proof piece 2. The negative electrode current collector 6 is located in the steel shell 1 and close to the bottom of the steel shell 1, and is used to connect with the end of the flattened roll core 5. The bottom of the steel shell 1 is provided with an opening 11, the explosion-proof piece 2 is arranged at the bottom of the steel shell 1, and the explosion-proof piece 2 covers the opening 11. The explosion-proof piece 2 is provided with an explosion-proof notch 21. The negative electrode current collector 6 is provided with a plurality of elastic sheets 61, the adjacent elastic sheets 61 are separated, and the elastic sheet 61 can be popped up to the side away from the flattened roll core 5.

[0033] The lithium battery provided by the present application can separate the steel shell 1 and the explosion-proof piece 2 for stamping, thereby improving the stability. The opening 11 is arranged at the bottom of the steel shell 1, the negative electrode current collector 6, the explosion-proof piece 2 and the opening 11 are arranged in sequence, and the negative electrode current collector 6 and the explosion-proof piece 2 are arranged in the steel shell 1. When the pressure in the steel shell 1 is too large, the pressure can be released in time, thereby effectively preventing explosion, and the explosion-proof property is good and the stability is high.

[0034] The lithium battery further comprises a cover plate 7, a positive electrode current collector 4 and a flattened roll core 5. The positive electrode current collector 4 and the negative electrode current collector 6 are arranged at two ends of the flattened roll core 5, and the positive electrode current collector 4 and the flattened roll core 5 are located in the steel shell 1. The cover plate 7 is arranged at the top of the steel shell 1, and the cover plate 7 is the positive electrode of the battery.

[0035] As shown in Figure 7As shown, the negative electrode current collecting plate 6 is provided with a plurality of spring clips 61, and adjacent spring clips 61 are separable. When the explosion-proof component 2 at the bottom of the steel shell 1 is opened, the spring clips 61 can bounce toward the side away from the flattened winding core 5, so that the negative electrode current collecting plate 6 opens outward, which is conducive to gas discharge.

[0036] In some embodiments, the negative electrode current collecting disc 6 has a planar structure, and a plurality of spring clips 61 can be arranged circumferentially around the central axis of the negative electrode current collecting disc 6. The spring clips 61 can be fan-shaped, with the tops and both sides of adjacent fans spaced or stacked, and the tail ends of the fans connected. When the explosion-proof component 2 at the bottom of the steel shell 1 is opened, the spring clips 61 rotate outward with the tail end as the rotation axis to open.

[0037] The steel shell 1 and the explosion-proof component 2 are two stamped parts. The bottom of the steel shell 1 is provided with an opening 11 , which can be a circular opening 11 .

[0038] The size of the explosion-proof component 2 matches the size of the opening 11 (the size of the explosion-proof component 2 is larger than the size of the opening 11 ), and the explosion-proof component 2 is arranged inside the steel shell 1 .

[0039] The explosion-proof component 2 and the steel shell 1 are welded together by laser welding to form a whole, so that the steel shell 1 has an explosion-proof function.

[0040] In one embodiment, Figure 4 、 Figure 6 As shown, there is a connecting arm 12 between the opening 11 and the side wall of the steel shell 1; the connecting arm 12 includes a connecting portion 121 and a supporting portion 123, the connecting portion 121 is connected to the peripheral wall of the steel shell 1, and the explosion-proof component 2 is provided on the supporting portion 123, and the vertical distance between the explosion-proof component 2 and the negative electrode current collecting disc 6 is greater than or equal to the vertical distance between the connecting portion 121 and the negative electrode current collecting disc 6.

[0041] The explosion-proof component 2 is provided with explosion-proof notches 21 .

[0042] In some embodiments, the explosion-proof notch 21 is provided on at least one side of the explosion-proof component 2 .

[0043] Among them, such as Figure 8 As shown, the explosion-proof notch 21 on the explosion-proof component 2 can be in a circular shape, a crisscross shape, a V shape or other shapes that are conducive to gas discharge.

[0044] In some embodiments, the explosion-proof notch 21 is provided on the side of the explosion-proof component 2 facing the inside of the steel shell 1 , so that the pressure inside the steel shell 1 can be relieved in time when the pressure is too high.

[0045] Or, in some embodiments, the explosion-proof notch 21 is arranged on the side of the explosion-proof member 2 facing outwards of the steel shell 1. When the battery in the steel shell 1 is short-circuited or for other reasons, the pressure in the steel shell 1 is too large, the explosion-proof notch 21 deforms away from the center of the steel shell 1. When the internal pressure reaches the explosion pressure, the deformation reaches the limit, the explosion-proof member 2 will break at the explosion-proof notch 21, timely pressure relief, effectively preventing the battery from exploding and catching fire.

[0046] Or, in some embodiments, the explosion-proof notch 21 is arranged on both sides of the explosion-proof member 2, and the positions of the two sides are symmetrical to facilitate pressure breakthrough.

[0047] Further, the size of the explosion-proof notch 21 is less than or equal to the size of the opening 11.

[0048] Specifically, there is a gap between the end of the explosion-proof notch 21 and the connecting arm 12, which avoids the overlap of the explosion-proof notch 21 and the connecting arm 12 (supporting part 123), affects the pressure relief, and has good stability.

[0049] Among them, the periphery of the explosion-proof member 2 is arranged on the connecting arm 12, that is, there is an overlapping part between the explosion-proof member 2 and the connecting arm 12.

[0050] Among them, the explosion-proof member 2 is arranged inside the steel shell 1, and the periphery of the explosion-proof member 2 is welded with the supporting part 123 to form a whole, so that the steel shell 1 has the explosion-proof function.

[0051] Further, the side of the explosion-proof member 2 facing inwards is flush with or lower than the inner side wall surface of the connecting part 121, that is, the vertical distance between the connecting part 121 and the negative current collector 6 is less than or equal to the vertical distance between the explosion-proof member 2 and the negative current collector 6, so that the connecting part 121 contacts the battery inside the steel shell 1, avoiding the contact and collision between the explosion-proof member 2 and the battery inside the steel shell 1, and improving the stability.

[0052] In another embodiment, as shown in Figure 4 , Figure 5 The opening 11 and the side wall surface of the steel shell 1 have a connecting arm 12; the connecting arm 12 includes a connecting part 121, a protruding part 122 and a supporting part 123, the connecting part 121 is connected with the peripheral wall of the steel shell 1, the protruding part 122 protrudes towards the inside of the steel shell 1, the two sides of the protruding part 122 are respectively connected with the connecting part 121 and the supporting part 123, and the explosion-proof member 2 is arranged on the supporting part 123; the vertical distance between the explosion-proof member 2 and the negative current collector 6 is greater than or equal to the vertical distance between the protruding part 122 and the negative current collector 6.

[0053] Among them, the connecting arm 12 is provided with the protruding part 122, the protruding part 122 protrudes towards the side close to the center of the steel shell 1, and the two sides of the protruding part 122 are respectively the supporting part 123 and the connecting part 121.

[0054] The connecting part 121 is connected with the peripheral wall of the steel shell 1, and the supporting part 123 is used for supporting the explosion-proof part 2, that is, the periphery of the explosion-proof part 2 is connected with the inner top surface of the supporting part 123, so that the explosion-proof part 2 is integrated with the steel shell 1 and has the explosion-proof function.

[0055] The explosion-proof part 2 is located in the steel shell 1, and the explosion-proof part 2 is arranged on the supporting part 123 and connected with the supporting part 123; the top surface of the explosion-proof part 2 is flush with the top surface of the protruding part 122, or the top surface of the explosion-proof part 2 is lower than the top surface of the protruding part 122; after the battery is placed in the steel shell, the vertical distance between the explosion-proof part 2 and the negative current collector 6 is greater than or equal to the vertical distance between the protruding part 122 and the negative current collector 6, so that the explosion-proof part 2 is prevented from contacting and colliding with the battery in the steel shell 1, and the stability is improved.

[0056] Further, the explosion-proof part 2 and the connecting arm 12 are welded together by laser welding to form an integral whole, so that the steel shell 1 has the explosion-proof function.

[0057] Further, the lithium battery provided by the application further comprises an anti-rust layer covering the connection between the explosion-proof part 2 and the steel shell 1.

[0058] The welding position of the explosion-proof part 2 and the steel shell 1 can be on the outside of the steel shell 1 or on the inside of the steel shell 1; in order to prevent rusting of the connection between the explosion-proof part 2 and the steel shell 1 and affect the explosion-proof performance, the application performs anti-rust treatment on the connection between the explosion-proof part 2 and the steel shell 1, for example, by applying UV glue curing, or applying anti-rust oil, anti-rust paint and the like to form an anti-rust layer at the connection between the explosion-proof part 2 and the steel shell 1, so as to protect the welding seam at the connection between the explosion-proof part 2 and the steel shell 1 and improve the sealing performance.

[0059] Further, the lithium battery provided by the application further comprises a protective part 3 covering the bottom of the explosion-proof part 2 and located outside the bottom of the steel shell 1.

[0060] Specifically, the protective part 3 can be a single-sided local adhesive structure, and the protective part 3 is pasted to the bottom of the steel shell 1 to protect the explosion-proof part 2 and prevent the explosion-proof part 2 from being damaged by external impact and affecting the explosion-proof performance.

[0061] Further, the vertical distance between the protective part 3 and the negative current collector 6 is less than or equal to the vertical distance between the connecting part 121 and the negative current collector 6.

[0062] Specifically, the bottom surface of the protective part 3 arranged at the bottom of the steel shell 1 is lower than the bottom surface of the connecting part 121, that is, the vertical distance between the bottom surface of the protective part 3 and the negative current collector 6 is less than or equal to the vertical distance between the bottom surface of the connecting part 121 and the negative current collector 6, so that the connecting part 121 is preferentially contacted with external parts, the protective part 3 is prevented from being contacted with external parts, and the explosion-proof part 2 arranged in the steel shell 1 is prevented from being damaged by external parts and affecting the explosion-proof performance.

[0063] The protection piece 3 in the application is a piece made of non-metallic material, including a piece made of polypropylene material.

[0064] The lithium battery provided by the application has the following advantages: the explosion-proof piece 2 is a separately punched piece, and the pressure is stable; the opening 11 is arranged at the bottom of the steel shell 1, the explosion-proof piece 2 is arranged inside the steel shell 1 and welded with the steel shell 1, so that the steel shell 1 has the explosion-proof function; when the pressure in the steel shell 1 is too large, the explosion-proof piece 2 deforms and breaks towards the side far away from the center of the steel shell 1, so as to timely release the pressure and prevent the battery from exploding and catching fire; the anti-rust layer is arranged at the connection between the explosion-proof piece 2 and the steel shell 1, so as to protect the connection and improve the sealing performance; the protection piece 3 is arranged at the bottom of the steel shell 1, the protection piece 3 covers the explosion-proof piece 2, so as to protect the explosion-proof piece 2 and avoid the collision between the explosion-proof piece 2 and external parts.

[0065] Based on the lithium battery in any of the above embodiments, the application further provides a production method of the lithium battery, including: welding the steel shell 1 and the explosion-proof piece 2 by laser welding, wherein the explosion-proof piece 2 is located inside the steel shell 1, and the periphery of the explosion-proof piece 2 is attached to the connecting arm 12; detecting the sealing performance of the connection between the steel shell 1 and the explosion-proof piece 2; welding the bottom of the steel shell 1 and the negative electrode current collector 6 by penetration welding, wherein the negative electrode current collector 6 is close to the explosion-proof piece 2; welding the steel shell 1 and the cover plate 7 by laser welding to seal; detecting the sealing performance of the connection between the steel shell 1 and the cover plate 7; cleaning, drying and applying the anti-rust layer at the connection between the steel shell 1 and the explosion-proof piece 2; and pasting the protection piece 3, wherein the protection piece 3 covers the bottom of the explosion-proof piece 2 and is located outside the bottom of the steel shell 1.

[0066] The production method of the lithium battery provided by the application has the following advantages: the explosion-proof piece 2 is a separately punched piece, and the pressure is stable; the opening 11 is arranged at the bottom of the steel shell 1, the explosion-proof piece 2 is arranged inside the steel shell 1 and welded with the steel shell 1, so that the steel shell 1 has the explosion-proof function; when the pressure in the steel shell 1 is too large, the explosion-proof piece 2 deforms and breaks towards the side far away from the center of the steel shell 1, so as to timely release the pressure and prevent the battery from exploding and catching fire; the anti-rust layer is arranged at the connection between the explosion-proof piece 2 and the steel shell 1, so as to protect the connection and improve the sealing performance; the protection piece 3 is arranged at the bottom of the steel shell 1, the protection piece 3 covers the explosion-proof piece 2, so as to protect the explosion-proof piece 2 and avoid the collision between the explosion-proof piece 2 and external parts.

[0067] In this embodiment, the model of the steel shell 1 is 46155, the diameter of the steel shell 1 is 46 mm, the height of the steel shell 1 is 155 mm, the domestic Baosteel cold-rolled steel strip is used as the raw material to manufacture the steel shell 1, the brand of the steel shell 1 is BDCK, the thickness of the raw material is 0.5 mm, the thickness of the tensile wall is 0.3 mm, and the diameter of the bottom hole is 28 mm.

[0068] The steel shell 1 is punched including blanking punch - shell bottom punch - shell bottom punch - stretch - stretch - thinning stretch - stretch - thinning stretch - stretch - stretch - stretch - punch shell bottom hole - shaping - cut waste - blanking. The steel shell 1 is electroplated by feeding - degreasing - washing - barrel changing - washing - pickling - washing - neutralizing - washing - activating - washing - nickel plating - recovery - washing - bleaching - washing - passivating - washing - barrel changing - washing - protection - washing - draining - drying - cooling - discharging - inspection, and the qualified electroplated steel shell 1 is obtained. If the steel shell 1 is made of pre-plated nickel steel strip, the nickel plating treatment is not needed after punching. The manufacture of the explosion-proof piece 2 includes punching - oil removal - cleaning - detection, and the qualified explosion-proof piece 2 is obtained.

[0069] After the steel shell 1 and the explosion-proof piece 2 are manufactured, the following steps are performed to assemble:

[0070] 1. Core preparation: positive and negative electrode homogenization - positive and negative electrode coating - positive and negative electrode rolling, slitting - winding - positive and negative electrode rubbing, and a rubbed core 5 is obtained.

[0071] 2. Welding of the current collector plate: the positive and negative current collector plates 6 are welded on the positive and negative ends of the rubbed core 5 by laser welding, and the negative current collector plate 6 is the welding area.

[0072] 3. Welding of the explosion-proof piece: the explosion-proof piece 2 is installed inside the steel shell 1, the explosion-proof notch 21 of the explosion-proof piece 2 faces the outside of the steel shell 1, the bottom surface of the explosion-proof piece 2 is in complete contact with the top surface of the supporting part 123, and laser welding is performed.

[0073] 4. Air tightness detection: the welded steel shell 1 is subjected to helium detection.

[0074] 5. Shell entry and bottom penetration welding: the negative electrode of the rubbed core 5 is installed in the steel shell 1, and the negative current collector plate 6 is in complete contact with the top surface of the raised part 122, and the laser passes through the groove of the raised part 122 to perform penetration welding on the bottom and the negative current collector plate 6.

[0075] 6. Welding of the cover plate 7: the cover plate 7 is assembled on the shell opening of the steel shell 1, and the laser welding is performed to seal.

[0076] 7. Air tightness detection: a small amount of helium is injected from the liquid injection hole 71 of the cover plate 7 to detect the air tightness of the bottom penetration welding and the cover plate 7 sealing.

[0077] 8. Liquid injection: electrolyte is injected from the liquid injection hole 71 of the cover plate 7.

[0078] 9. Liquid injection hole 71 sealing and leakage detection: a small amount of helium is injected from the liquid injection hole 71 of the cover plate 7, a rivet 8 is used to seal the liquid injection hole 71, and finally the sealing is subjected to helium detection.

[0079] 10. Cleaning and protection: clean and dry the battery, spray UV glue (anti-rust glue, anti-rust paint) at the groove of the protruding part 122, solidify by irradiating ultraviolet rays, form an anti-rust layer, and further improve the sealing of the lithium battery;

[0080] 11. The protective piece 3 is pasted on the outer bottom surface of the supporting part 123.

[0081] 12. Pre-charge and capacity distribution: charge the battery.

[0082] The above completes the entire battery production.

[0083] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art will understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solution to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A lithium battery, characterized in that: include: Steel shell, negative electrode collector plate, explosion-proof parts; The negative electrode current collecting disc is located inside the steel shell and close to the bottom of the steel shell, and the negative electrode current collecting disc is used to connect to the end of the flattened winding core; The bottom of the steel shell is provided with an opening, the explosion-proof component is provided at the bottom of the steel shell, and the explosion-proof component covers the opening, and the explosion-proof component is provided with explosion-proof notches; The negative electrode current collecting disc is provided with a plurality of spring sheets, adjacent spring sheets are separated from each other, and the spring sheets can be bounced toward a side away from the flattened winding core; A connecting arm is provided between the opening and the side wall of the steel shell; The connecting arm includes a connecting portion, a raised portion, and a supporting portion. The connecting portion is connected to the peripheral wall of the steel shell. The raised portion protrudes toward the interior of the steel shell. Both sides of the raised portion are transitionally connected to the connecting portion and the supporting portion respectively. The explosion-proof component is provided on the supporting portion. The vertical distance between the explosion-proof component and the negative electrode current collecting disc is greater than or equal to the vertical distance between the protrusion and the negative electrode current collecting disc; The lithium battery further includes a protective member, which covers the bottom of the explosion-proof member and is located outside the bottom of the steel shell; The vertical distance between the protective member and the negative electrode current collecting disk is less than or equal to the vertical distance between the connecting portion and the negative electrode current collecting disk; The protective part is made of non-metal.

2. The lithium battery according to claim 1, characterized in that The size of the explosion-proof notch is smaller than or equal to the size of the opening.

3. The lithium battery according to claim 1, wherein The lithium battery further includes an anti-rust layer, which is provided to cover the connection between the explosion-proof component and the steel shell.

4. The lithium battery according to claim 1, characterized in that The explosion-proof notch is provided on at least one side of the explosion-proof component.

5. A method for producing a lithium battery, based on the lithium battery according to any one of claims 1 to 4, characterized in that: include: Welding the steel shell to the explosion-proof component by laser welding, wherein the explosion-proof component is located inside the steel shell, and the periphery of the explosion-proof component is in contact with the connecting arm; Detecting the sealing performance of the connection between the steel shell and the explosion-proof component; Welding the bottom of the steel shell to the negative electrode current collecting plate by penetration welding, wherein the negative electrode current collecting plate is close to the explosion-proof component; The steel shell and the cover plate are welded together by laser welding to seal the steel shell; Checking the sealing performance of the connection between the steel shell and the cover plate; Clean and dry the battery, and apply an anti-rust layer to the connection between the steel shell and the explosion-proof component; A protective piece is pasted, wherein the protective piece covers the bottom of the explosion-proof piece and is located outside the bottom of the steel shell.

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