Battery cover plate and battery

Abstract

The utility model discloses a battery cover plate and a battery, and the battery cover plate comprises a cover plate main body part, an explosion-proof part, a roll core connecting part and a sealing part, an explosion-proof part is arranged at the top of the cover plate main body part in a surrounding manner; a concave roll core connecting part is arranged on the inner side of the explosion-proof part; the roll core connecting part is used for being connected with a negative tab at the bottom of a roll core of the battery; the sealing part is arranged in the center of the top of the roll core connecting part; the outer side edge of the periphery of the cover plate main body part is used for being hermetically connected with a bottom opening of a battery shell of the battery; according to the battery cover plate and the battery disclosed by the utility model, the battery cover plate can be safely and reliably connected with the negative electrode lug of the roll core, the reliability of electric connection of the negative electrode side of the battery is ensured, the production quality of the battery is ensured, the yield of the battery is improved, and the battery cover plate and the battery have great practical significance.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery cover and a battery. Background Art

[0002] Lithium-ion batteries have the advantages of high specific energy, many cycles and long storage time. They are not only widely used in portable electronic devices (such as mobile phones, digital cameras and laptops), but also widely used in large and medium-sized electric equipment such as electric vehicles, electric bicycles and power tools. Therefore, the performance requirements for lithium-ion batteries are getting higher and higher.

[0003] Currently, single-cell batteries, especially large cylindrical full-tab lithium-ion batteries (large cylindrical batteries, i.e., large-sized cylindrical batteries such as 4680 and 4695), have complex structures and are difficult to assemble, especially the electrical connection on the negative electrode side. Conventional physical connection methods on the negative electrode side cannot guarantee the reliability of the connection, resulting in insufficient reliability and thus the reliability of the electrical connection on the negative electrode side of the battery. This, in turn, makes it difficult to guarantee the production quality of the battery, affecting the battery yield rate.

[0004] Therefore, there is an urgent need to develop a technology that can solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a battery cover and a battery in view of the technical defects in the prior art.

[0006] To this end, the utility model provides a battery cover, which includes: a cover body, an explosion-proof portion, a winding core connecting portion, and a sealing portion;

[0007] The bottom of the cover body is surrounded by an explosion-proof portion protruding downward;

[0008] A concave winding core connecting portion is provided on the inner side of the explosion-proof portion;

[0009] The winding core connection portion is used to connect to the negative electrode ear at the bottom of the battery winding core;

[0010] A sealing portion is provided at the bottom center of the winding core connection portion;

[0011] The outer edges of the cover body are used to be sealed with the bottom opening of the battery shell of the battery;

[0012] The outer edges of the main body of the cover plate are surrounded by a circle of cover plate main body flanges protruding outwards;

[0013] The cover body flange is used to be sealed and connected to the bottom opening of the battery shell of the battery;

[0014] A circle of concave cover plate main body sinking platform is arranged around the inner side of the cover plate main body flange;

[0015] Explosion-proof part, including: explosion-proof boss and explosion-proof notch;

[0016] An explosion-proof boss is provided on the inner side of the bottom of the cover plate main body sinking platform on the cover plate main body in a downwardly protruding manner;

[0017] The explosion-proof boss is provided with a concave explosion-proof notch.

[0018] In addition, the present invention also provides a battery, comprising the battery cover as described above.

[0019] It can be seen from the technical solution provided by the above utility model that compared with the existing technology, the utility model provides a battery cover and a battery with scientific design, which can safely and reliably connect the battery cover to the negative electrode ear of the winding core, ensure the reliability of the electrical connection on the negative electrode side of the battery, which is conducive to ensuring the production quality of the battery and improving the yield rate of the battery, and has important practical significance.

[0020] For the utility model, the traditional negative electrode busbar is eliminated and the physical connection method of the negative electrode side is designed as follows: the battery cover and the negative electrode ear of the winding core are laser penetrated and welded, that is, the battery cover directly penetrates the negative electrode ear of the winding core for laser welding, which can ensure the reliability of the electrical connection on the negative electrode side of the battery, is conducive to reducing the cost of battery materials, and improving the battery assembly efficiency and yield rate.

[0021] The application of this utility model helps to solve the problems of low welding process capability and insufficient welding reliability on the negative electrode side connection during assembly of existing batteries, effectively reducing production costs, ensuring battery safety, and improving the market application prospects of battery manufacturers' products. The battery cover plate structural design and battery assembly solution provided by this utility model are highly reliable and easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1a This is a schematic diagram of the three-dimensional structure of a battery cover provided by the present invention when placed upside down in embodiment 1;

[0023] Figure 1b This is a schematic diagram of the three-dimensional structure of a battery cover provided by the present invention when placed horizontally and upright in embodiment 1;

[0024] Figure 2a This is a schematic diagram of the three-dimensional structure of a battery cover provided by the utility model when placed upside down in embodiment 2;

[0025] Figure 2bThis is a schematic diagram of the three-dimensional structure of a second embodiment of a battery cover provided by the present invention when placed horizontally and upright;

[0026] Figure 3a This is a schematic diagram of the three-dimensional structure of a battery cover provided by the present invention when placed upside down in embodiment 3;

[0027] Figure 3b This is a schematic diagram of the three-dimensional structure of a battery cover provided by the present invention when placed horizontally and upright;

[0028] Figure 4 This is a schematic diagram of the welding trajectory of the battery cover plate of Example 1 provided by the present invention when penetrating the welding core (specifically, the negative electrode ear of the core located below);

[0029] Figure 5 This is a schematic diagram of the welding trajectory of the battery cover plate of Example 3 provided by the present invention when penetrating the welding core (specifically, the negative electrode ear of the core located below);

[0030] Figure 6 This is a cross-sectional view of the negative electrode of a battery provided by the present invention after the battery shell, winding core, battery cover and other components are welded;

[0031] Figure 7 This is a cross-sectional view of a battery provided by the utility model;

[0032] In the figure, 1-battery cover; 11-cover body; 111-cover body flange; 112-cover body sink;

[0033] 12- explosion-proof part; 121- explosion-proof boss; 122- explosion-proof notch;

[0034] 13- core connection portion; 14- sealing portion;

[0035] 141 - center boss of cover plate; 142 - center slot of cover plate; 143 - center hole of cover plate.

[0036] 2-sealing nail; 3-sealing rubber plug; 4-battery housing; 5-winding core;

[0037] 6-busbar; 7-rivet; 8-inner gasket; 9-insulating sealing ring. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0040] In the description of this patent, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," and "set" should be understood in a broad sense. For example, they can refer to fixed connection or set, detachable connection or set, or integral connection or set. Those skilled in the art will understand the specific meanings of the above terms in this patent based on the specific circumstances.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0042] See also Figure 1a to Figure 1b 、 Figure 2a to Figure 2b 、 Figure 3a to Figure 3b 、 Figures 4 to 7 The utility model provides a battery cover, which is used in a battery, and includes: a cover body portion 11, an explosion-proof portion 12, a winding core connecting portion 13, and a sealing portion 14;

[0043] The bottom of the cover body 11 is surrounded by an explosion-proof portion 12 protruding downward;

[0044] The inner side of the explosion-proof part 12 is provided with a concave winding core connecting part 13;

[0045] The winding core connection portion 13 is used to connect to the negative electrode ear at the bottom of the winding core 5 of the battery;

[0046] A sealing portion 14 is provided at the bottom center of the winding core connecting portion 13;

[0047] The outer edges of the cover body 11 are used to be sealed with the bottom opening of the battery housing 4 of the battery.

[0048] It should be noted that the cover body 11 is used to achieve sealing by laser welding with the bottom opening of the battery housing 4;

[0049] The explosion-proof part 12 is used to relieve explosions and release pressure when the battery experiences thermal runaway;

[0050] The winding core connection portion 13 is used to connect to the negative electrode tab at the bottom of the winding core 5 by laser welding to ensure electrical connection;

[0051] The sealing portion 14 is used for battery liquid injection, formation exhaust, and subsequent welding with the sealing pin 2.

[0052] In the present invention, a circle of outwardly protruding cover plate body flanges 111 is provided around the outer edges of the cover plate body 11;

[0053] The flange 111 of the cover body is used to be sealed and connected to the bottom opening of the battery housing 4 of the battery.

[0054] A circle of concave cover plate body sinking platform 112 is arranged around the inner side of the cover plate body flange 111;

[0055] In a specific implementation, the flange 111 of the cover body and the bottom opening of the battery housing 4 of the battery are sealed by welding (ie, laser welding).

[0056] It should be noted that the cover plate main body flange 111 is located at the outermost area of the battery cover plate and is used to seal the bottom opening of the battery housing 4 .

[0057] In specific implementation, the battery cover is formed by stamping.

[0058] It should be noted that the battery cover is manufactured by stamping, the base material thickness can be selected from 0.3mm to 0.8mm, and the base material can be selected from SPCC (generally cold-rolled carbon steel sheets and strips).

[0059] or stainless steel;

[0060] In specific implementation, the cover plate main body flange 111 is connected and sealed with the battery shell 4 by laser welding. Specifically, a ring spot laser can be selected, the laser welding power is 350w-850w, the welding trajectory is a straight line, and the effective welding penetration is 0.10mm-0.35mm.

[0061] In a specific implementation, the inner side surface of the cover plate main body flange 111 (ie, the outer edge side surface of the cover plate main body sink 112) is a vertical plane.

[0062] In a specific implementation, the outer side surfaces of the flange 111 of the cover body are flush with the outer side surfaces of the bottom opening of the battery housing 4 .

[0063] It should be noted that in order to improve the reliability of laser welding sealing, the outer edge side of the cover body sink 112 is as straight as possible, and the battery cover 1 is tightly matched with the bottom opening area of the battery shell 4 after installation.

[0064] In specific implementation, an explosion-proof portion 12 is provided around the inner side of the bottom of the cover body sink 112;

[0065] In the present invention, the explosion-proof portion 12 includes: an explosion-proof boss 121 and an explosion-proof notch 122;

[0066] The explosion-proof boss 121 is provided on the inner side of the bottom of the cover body sink 112 on the cover body 11 in a downwardly protruding manner;

[0067] The explosion-proof boss 121 is provided with a concave explosion-proof notch 122 (a downwardly protruding groove);

[0068] In specific implementation, such as Figure 1a 、 Figure 1b In the battery cover of the first embodiment shown, the explosion-proof boss 121 is circumferentially disposed on the inner bottom side of the cover body sink 112 on the cover body 11 and is spaced apart from the cover center boss 141 of the sealing portion 14 (via the concave winding core connecting portion 13);

[0069] Furthermore, for Figure 1a 、 Figure 1b In the battery cover of the first embodiment shown, the sealing portion 14, the winding core connecting portion 13 and the explosion-proof portion 12 are sequentially distributed from the inside to the outside along the radial direction of the cover body 11;

[0070] In specific implementation, such as Figure 2a 、 Figure 2b In the battery cover of the second embodiment shown, the explosion-proof boss 121 is circumferentially arranged on the inner bottom side of the cover body sink 112 on the cover body 11, and is connected to the cover center boss 141 of the sealing portion 14 through three first connecting bosses 1210.

[0071] The three first connection bosses 1210 are used to separate the upwardly concave winding core connection portion 13 into three independent grooves.

[0072] In specific implementation, such as Figure 3a 、 Figure 3b The battery cover of the third embodiment shown, the explosion-proof boss 121, includes a circular boss main body portion 1211;

[0073] The boss body portion 1211 is circumferentially disposed on the inner side of the bottom of the cover body sink 112 on the cover body portion 11;

[0074] The inner side of the boss body portion 1211 is connected to the outer sides of the central boss 141 of the cover plate of the sealing portion 14 through three second connecting bosses 1212;

[0075] The three second connection bosses 1212 are used to separate the upwardly concave winding core connection portion 13 into three independent grooves.

[0076] In a specific implementation, the explosion-proof notch 122 is in the shape of an arc.

[0077] In a specific implementation, the material thickness at the explosion-proof notch 122 is smaller than the material thickness of the cover plate main body 11;

[0078] In a specific implementation, the explosion-proof notch 122 is formed by stamping;

[0079] It should be noted that the explosion-proof notch 122 is generally stamped, and the shape of the explosion-proof notch 122 can be circular or irregular (such as crescent-shaped, L-shaped or arc-shaped), etc. When the battery has thermal runaway, the explosion-proof notch 122 in the explosion-proof portion 12 of the battery cover opens, quickly releasing the pressure inside the battery, thereby effectively improving the safety of the battery.

[0080] It should be noted that the shape of the explosion-proof notch 122 of the battery cover is preferably a ring shape with a gap (ie, an opening) (ie, not a complete ring shape, but actually an arc shape).

[0081] In specific implementation, the shape of the winding core connection portion 13 (i.e., the shape of the groove) can be, but is not limited to, a "cross shape" (e.g. Figure 1a 、 Figure 1b shown), "three-petal type" (e.g. Figure 2a 、 Figure 2b shown) and "ring" (e.g. Figure 3a 、 Figure 3b shown) etc.

[0082] In a specific implementation, the winding core connection portion 13 is connected to the negative electrode tab at the bottom of the winding core 5 by laser welding.

[0083] Furthermore, the laser welding trajectory A is in the shape of a straight line (e.g. Figure 4 As shown), the shape of the spiral (as Figure 5 as shown) or in the shape of a sine curve.

[0084] It should be noted that the laser welding between the core connection portion 13 and the negative electrode ear at the bottom of the core 5 can be performed using a single-mode continuous laser with a laser welding power of 300W-850W. The welding trajectory can be in the form of a straight line, a spiral line, a sine curve, etc. The effective welding strength is greater than 40N and the effective penetration depth is greater than 0.10mm.

[0085] In a specific implementation, the winding core connection portion 13 is connected to the negative electrode ear at the bottom of the winding core 5 by laser penetration welding.

[0086] It should be noted that the welding trajectory of the laser penetration welding between the winding core connection portion 13 and the negative electrode tab of the winding core 5 is generally: a radially distributed welding trajectory, or a welding trajectory including a radially distributed welding trajectory and a circumferentially distributed welding trajectory.

[0087] It should be noted that the size range of the winding core connection portion 13 should be consistent with the weldable area of the existing electrode group formed by cutting and stacking the tabs, and can generally be selected from φ15mm-φ40mm (i.e., the size range of the winding core connection portion 13, i.e., the distribution range, is the size range of 15mm to 40mm from the center point of the cover plate center hole 143);

[0088] In the present invention, in a specific implementation, the upper concave depth of the winding core connecting portion 13 is greater than or equal to the upper concave depth of the cover plate main body sinking platform 112 of the cover plate main body 11;

[0089] In this utility model, if Figure 1a to Figure 1b 、 Figure 2a to Figure 2b 、 Figure 3a to Figure 3b 、 Figure 6 As shown, a sealing portion 14 is provided at the bottom center of the winding core connecting portion 13;

[0090] The sealing portion 14 is used for filling, exhausting and sealing the battery cell;

[0091] In a specific implementation, the sealing portion 14 includes a central boss 141 of the cover plate distributed around the center;

[0092] The cover plate center boss 141 is protruding downward and is provided at the bottom of the winding core connecting portion 13;

[0093] At the bottom center of the cover plate center boss 141, there is a concave cover plate center slot 142;

[0094] A vertically penetrating cover plate center hole 143 is provided at the center of the cover plate center slot 142;

[0095] Furthermore, the central slot 142 of the cover plate is welded and sealed to a sealing pin 2 .

[0096] Furthermore, a sealing rubber plug 3 is inserted into the central hole 143 of the cover plate;

[0097] Furthermore, there is an interference fit between the sealing rubber plug 3 and the central hole 143 of the cover plate.

[0098] It should be noted that the center slot 142 of the cover plate is used to accommodate the placement and welding of the sealing pin 2; the center hole 143 of the cover plate is used to inject liquid (inject electrolyte) into the winding core (i.e., the battery cell electrode group) placed inside the battery shell, and to place the sealing plug 3.

[0099] Furthermore, the central slot 142 of the cover plate is connected to the sealing pin 2 by laser welding;

[0100] The welding trajectory of laser welding is straight or circular.

[0101] It should be noted that, in specific implementation, for the battery assembled with the battery cover of the utility model, after the injection and exhaust operations are completed, the sealing plug 3 is inserted into the center hole 143 of the cover, and then the center slot 142 of the cover is connected with the sealing pin 2 by laser welding to achieve sealing. Specifically, a single-mode continuous laser can be selected, and the laser welding power is 300w-600w. The welding trajectory of the laser welding can be straight, circular, etc.

[0102] It should be noted that the shape and size of the sealing pin 2 correspond to the shape and size of the cover plate center slot 142 where the cover plate center hole 143 has been inserted into the sealing plug 3. The overall cross-sectional shape of the sealing pin 2 is circular.

[0103] Furthermore, the bottom surface of the cover plate center slot 142 is a horizontal surface;

[0104] The angle between the side walls and the top surface of the central slot 142 of the cover plate is greater than or equal to 90°.

[0105] It should be noted that in order to ensure the welding effect of the sealing pin 2, it is generally necessary to perform dry ice cleaning or laser cleaning on the center slot 142 of the cover plate corresponding to the sealing pin 2. To ensure the cleaning effect, the angle between the side and the top surface of the center slot 142 of the cover plate is generally not less than 90 degrees.

[0106] It should be noted that, for the present invention, the battery cover mainly includes a cover body, an explosion-proof part, a core connection part and a sealing part. The cover body is laser welded with the battery shell to seal the bottom opening of the battery shell; an explosion-proof notch is provided in the explosion-proof part, and the material thickness at the notch is less than the thickness of the cover body, which plays an explosion-proof and pressure-relieving role in extreme cases; the core connection part is used to be welded to the negative pole ear of the core to maintain electrical connection; the sealing part is used to seal the battery after the battery cell is filled with liquid and the formation exhaust operation.

[0107] Based on the battery cover provided by the above utility model, see Figure 6 、 Figure 7 As shown, the present invention also provides a battery, which includes the battery cover mentioned above.

[0108] In the present invention, in a specific implementation, the battery comprises a hollow, cylindrical battery housing 4;

[0109] Inside the battery housing 4, a winding core (i.e., a battery cell electrode group) 5 is provided;

[0110] The top of the battery housing 4 is sealed with a positive electrode cover plate (which is a positive electrode column assembly) serving as the positive electrode output terminal;

[0111] The positive electrode tab at the top of the core (i.e., the battery cell electrode group) 5 is connected to a busbar 6 (specifically, welded);

[0112] Busbar 6, connected to the positive electrode cover (which is a positive electrode column assembly);

[0113] The bottom of the battery housing 4 is sealed with the battery cover 1 as described above, which serves as the negative output terminal;

[0114] The top of the battery cover 1 is connected to the negative electrode ear at the bottom of the winding core (i.e., the battery cell electrode group) 5;

[0115] The edges of the battery cover 1 are sealed and connected to the inner side walls around the bottom opening of the battery housing 4 (specifically, they are welded and fixed).

[0116] In specific implementation, the positive electrode ear on the top of the winding core (i.e., the battery cell electrode group) 5 is welded and fixed to the bottom surface of the busbar 6;

[0117] The top surface of the busbar 6 is welded and fixed to the bottom of the positive electrode cover.

[0118] In a specific implementation, the negative electrode ear at the bottom of the core (i.e., the battery cell electrode group) 5 and the positive electrode ear at the top of the core (i.e., the battery cell electrode group) 5 are both full electrode ears.

[0119] In a specific implementation, the battery cover 1 and the negative electrode ear at the bottom of the winding core (ie, the battery cell electrode group) 5 are connected by laser welding, and specifically, laser penetration welding can be used.

[0120] In specific implementation, the positive electrode cover (which is a positive electrode column assembly) includes: rivets 7 and insulating sealing rings 9;

[0121] The circumferential outer wall of the rivet 7 is covered with an insulating sealing ring 9;

[0122] An insulating sealing ring 9 is located between the top opening of the battery housing 4 and the rivet 7;

[0123] Furthermore, an annular inner gasket 8 (which is an insulating gasket) is sleeved on the outer side of the lower portion of the insulating sealing ring 9;

[0124] Furthermore, the inner gasket 8 is located between the insulating sealing ring 9 and the busbar 6 .

[0125] Furthermore, the rivet 7 is formed by cold heading or machining;

[0126] The insulating sealing ring 8 is integrally injection-molded, and its material can be selected from PPS, PBT, PFA, etc.

[0127] It should be noted that the battery housing 4 and the positive electrode cover are separated and insulated from each other (for example, separated from each other by an insulating sealing ring 8).

[0128] It should also be noted that, in the present invention, after the rivet 7 and the battery housing 4 are riveted together, the outer sides of the insulating seal ring 8 abut against the inner wall of the top opening of the battery housing 4 to provide insulation.

[0129] It should be noted that the rivet 7 is used to be riveted to the center of the top panel of the battery housing 4. The insulating seal ring 8 is fixed by the rivet 7 through riveting to the battery housing 4.

[0130] It should be noted that the battery mainly includes components such as a battery cover, a winding core, a busbar and a battery shell. The busbar and the positive pole ear of the winding core are welded to maintain electrical connection; the rivet 7 serving as the positive pole column is welded to the busbar to maintain electrical connection; the battery cover 1 is welded to the negative pole ear of the winding core to maintain electrical connection.

[0131] For the present invention, in order to prepare the above-mentioned battery, the present invention also provides a method for preparing the battery, comprising the following steps:

[0132] Step S1, using laser cutting equipment (existing equipment) to prepare positive and negative electrode sheets with tabs cut;

[0133] It should be noted that the full-pole tab technology is proposed in contrast to the traditional single-pole tab or multi-pole tab. The current full-pole tab technology for lithium-ion batteries mainly includes two types, namely flattened tab forming and cut-and-stacked tab forming. Cut-and-stacked tab forming technology is widely used because of its low self-discharge rate and less metal foreign matter. In order to ensure the flattening forming effect of the cut tabs, the tabs on the edges of the positive and negative electrodes need to be cut with laser die-cutting equipment. The tabs after cutting are cut tabs.

[0134] It should be noted that the preparation technology of the positive and negative electrode sheets with cut tabs is the existing well-known preparation technology of full-tab batteries and will not be described in detail here.

[0135] It should be noted that the method for preparing the positive electrode sheet and the negative electrode sheet in step S1 is an existing conventional method.

[0136] Step S2, performing a winding operation of the positive electrode sheet, the negative electrode sheet and the separator, pre-folding the tabs during the winding process, and then using a tab flattening device to flatten the tabs (the tab flattening operation is an existing conventional tab processing operation and is performed using an existing tab flattening device), and after flattening, a cylindrical battery core is obtained;

[0137] In step S2, the separator is located between the positive electrode sheet and the negative electrode sheet to separate the two and avoid short circuit.

[0138] Step S3, performing a laser penetration welding operation between the busbar 6 and the positive electrode tab on the top of the winding core 5;

[0139] Step S4, for the winding core 5 after welding with the busbar 6, the positive electrode ear of the winding core 5 is coated with glue;

[0140] Step S5, performing a laser penetration welding operation between the battery cover 1 and the negative electrode tab at the bottom of the winding core 5;

[0141] Step S6: The welded winding core 5 is placed into the battery housing 4, and then the rivet 7 serving as the positive electrode column is welded to the busbar 6;

[0142] Step S7, performing a laser sealing welding operation between the battery cover 1 and the bottom opening of the battery housing 4;

[0143] In step S8, the electrolyte is injected into the battery housing 4 through the central hole 143 of the battery cover 1, and then the battery is formed. After the formation is completed, the sealing plug 3 is inserted and the sealing pin 2 is welded in the central groove 142 of the battery cover 1 to finally prepare a battery (specifically a single cylindrical lithium-ion battery).

[0144] Compared with the prior art, the utility model provides a battery cover, a battery, and a battery preparation method, which are scientifically designed and can safely and reliably connect the battery cover to the negative electrode ear of the winding core, thereby ensuring the reliability of the electrical connection on the negative electrode side of the battery, which is beneficial to ensuring the production quality of the battery and improving the yield rate of the battery, and has great practical significance.

[0145] For the utility model, the traditional negative electrode busbar is eliminated and the physical connection method of the negative electrode side is designed as follows: the battery cover and the negative electrode ear of the winding core are laser penetrated and welded, that is, the battery cover directly penetrates the negative electrode ear of the winding core for laser welding, which can ensure the reliability of the electrical connection on the negative electrode side of the battery, is conducive to reducing the cost of battery materials, and improving the battery assembly efficiency and yield rate.

[0146] The application of this utility model helps to solve the problems of low welding process capability and insufficient welding reliability on the negative electrode side connection during assembly of existing batteries, effectively reducing production costs, ensuring battery safety, and improving the market application prospects of battery manufacturers' products. The battery cover plate structural design and battery assembly solution provided by this utility model are highly reliable and easy to industrialize.

[0147] By applying the utility model, due to the special design of the structure of the battery cover, the traditional negative busbar of the single battery is eliminated, the assembly process of the single cylindrical battery is reduced, and cost reduction and efficiency improvement are achieved.

[0148] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A battery cover, characterized in that: include: Cover plate main body (11), explosion-proof portion (12), winding core connecting portion (13), and sealing portion (14); The bottom of the cover plate main body (11) is surrounded by an explosion-proof portion (12) protruding downward; A concave winding core connecting portion (13) is provided on the inner side of the explosion-proof portion (12); A winding core connecting portion (13) is used to connect to the negative electrode ear at the bottom of the winding core (5) of the battery; A sealing portion (14) is provided at the bottom center of the winding core connecting portion (13); The outer edges of the cover plate main body (11) are used for sealingly connecting with the bottom opening of the battery housing (4) of the battery; The outer edges of the cover plate main body (11) are surrounded by a circle of cover plate main body flanges (111) protruding outwards; The cover plate main body flange (111) is used for sealingly connecting with the bottom opening of the battery housing (4) of the battery; A circle of concave cover plate main body sinking platform (112) is arranged around the inner side of the cover plate main body flange (111); The explosion-proof portion (12) includes an explosion-proof boss (121) and an explosion-proof notch (122); An explosion-proof boss (121) is provided on the inner side of the bottom of the cover plate main body sink (112) on the cover plate main body (11) in a downwardly protruding manner; A concave explosion-proof notch (122) is provided on the explosion-proof boss (121).

2. The battery cover according to claim 1, wherein: The cover plate main body flange (111) and the bottom opening of the battery housing (4) of the battery are sealed and connected by laser welding; and / or, The winding core connection portion (13) is connected to the negative electrode ear at the bottom of the winding core (5) by laser welding; and / or, An explosion-proof portion (12) is provided around the inner side of the bottom of the cover plate main body sinking platform (112); and / or, The inner side surface of the cover plate main body flange (111) is a vertical plane; and / or, The outer side surfaces of the flange (111) of the cover body are flush with the outer side surfaces of the bottom opening of the battery housing (4); and / or, The concave depth of the winding core connecting portion (13) is greater than or equal to the concave depth of the cover plate main body sinking platform (112) of the cover plate main body portion (11); and / or, The material thickness at the explosion-proof notch (122) is smaller than the material thickness of the cover plate main body (11); and / or, The explosion-proof notch (122) is in the shape of a circular ring with an opening.

3. The battery cover according to claim 1, wherein: The explosion-proof boss (121) is circumferentially arranged on the inner side of the bottom of the cover plate main body sink (112) on the cover plate main body (11), and is spaced apart from the cover plate central boss (141) of the sealing portion (14); The sealing portion (14), the winding core connecting portion (13) and the explosion-proof portion (12) are sequentially distributed from the inside to the outside along the radial direction of the cover plate main body (11).

4. The battery cover according to claim 1, wherein: The explosion-proof boss (121) is circumferentially arranged on the inner bottom side of the cover plate main body sink (112) on the cover plate main body (11), and is connected to the cover plate central boss (141) of the sealing portion (14) and the cover plate central boss (141) of the sealing portion (14) through three first connecting bosses (1210); The three first connecting bosses (1210) are used to separate the upwardly concave winding core connecting portion (13) into three independent grooves.

5. The battery cover according to claim 1, wherein: The explosion-proof boss (121) comprises a circular boss main body (1211); The boss main body part (1211) is circumferentially arranged on the inner side of the bottom of the cover plate main body sinking platform (112) on the cover plate main body part (11); The inner side of the boss main body part (1211) is connected to the outer sides of the central boss (141) of the cover plate of the sealing part (14) through three second connecting bosses (1212); The three second connection bosses (1212) are used to separate the upwardly concave winding core connection portion (13) into three independent grooves.

6. The battery cover according to claim 1, wherein: The sealing portion (14) includes a central boss (141) of the cover plate distributed around the center; The cover plate center boss (141) is arranged on the bottom of the winding core connecting portion (13) in a downwardly protruding manner; A concave cover plate center slot (142) is provided at the bottom center of the cover plate center boss (141); A vertically penetrating cover plate center hole (143) is provided at the center of the cover plate center slot (142); The center groove (142) of the cover plate is welded and sealed to a sealing pin (2); A sealing rubber plug (3) is inserted into the central hole (143) of the cover plate.

7. The battery cover according to claim 6, wherein: There is an interference fit between the sealing rubber plug (3) and the center hole (143) of the cover plate; and / or, The bottom surface of the center slot (142) of the cover plate is a horizontal surface; The included angle between the side walls and the top surface of the central slot (142) of the cover plate is greater than or equal to 90 degrees.

8. A battery, characterized in that: The invention comprises the battery cover according to any one of claims 1 to 7.

9. The battery according to claim 8, wherein The battery comprises a hollow, cylindrical battery housing (4); A winding core (5) is provided in the battery housing (4); A positive electrode cover serving as a positive electrode output terminal is sealed and provided on the top of the battery housing (4); The positive electrode tab on the top of the winding core (5) is connected to a busbar (6); A busbar (6) connected to the positive electrode cover; The bottom of the battery housing (4) is sealed with a battery cover as claimed in any one of claims 1 to 7, which serves as a negative output terminal; The top of the battery cover (1) is connected to the negative electrode ear at the bottom of the winding core (5); The edges of the battery cover (1) are sealed to the inner side walls around the bottom opening of the battery housing (4); The positive electrode cover comprises: a rivet (7) and an insulating sealing ring (9); The circumferential outer wall of the rivet (7) is covered with an insulating sealing ring (9); an insulating sealing ring (9) located between the top opening of the battery housing (4) and the rivet (7); The outer side of the lower part of the insulating sealing ring (9) is covered with a circular inner gasket (8).

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