Full-tab large cylindrical battery

Abstract

The utility model provides a full-tab large cylindrical battery, one end of a roll core is flattened to form a positive pole full tab, the other end of the roll core is flattened to form a negative pole full tab, a positive pole current collecting disc comprises a base body and a connecting piece which is connected with the base body and is integrally formed with the base body, the base body is provided with a plurality of spaced positive pole welding areas, and the positive pole welding areas are welded with the positive pole current collecting disc. The positive electrode current collecting disc is provided with a plurality of positive electrode welding areas, the positive electrode full tab is welded on the positive electrode welding areas, the positive electrode of the battery is led out after the connecting piece is bent, the negative electrode current collecting disc is provided with a plurality of negative electrode welding areas at intervals, and the negative electrode full tab is welded on the negative electrode welding areas. And the welding area is increased, the problems of insufficient welding of the tabs or welding penetration of the tabs and the like due to superposition of a plurality of tabs and insufficient welding strength are avoided, the strength of the collector plate and the fixing strength of the roll core are enhanced, the diversion area is increased, and the capacity and the cycle performance of the battery are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a full tab big cylindrical battery. BACKGROUND

[0002] In recent years, the global new energy automobile develops rapidly, drives the high -speed growth of lithium ion battery, and the current new energy automobile industry puts forward higher capacity, high energy density demand to lithium battery industry. 46 series (battery diameter is 46mm) big cylindrical battery is considered as the ideal battery cylindrical lithium ion battery suitable for future new energy automobile and large -scale energy storage system because of capacity, energy density, group convenience and other advantages. At present, 46 series battery adopts multiple tabs and is directly welded on the cap, and this structure has no big problem for small diameter cylindrical lithium battery, but for 46 series battery, there are problems such as tab virtual welding or tab welding through due to multiple tabs superposition and insufficient welding strength, which affect battery performance.

[0003] Therefore, it is necessary to provide a new full tab big cylindrical battery to overcome the above defects. SUMMARY

[0004] The utility model discloses a full tab big cylindrical battery, solve the problem that tab virtual welding or tab welding through appears due to multiple tabs superposition and insufficient welding strength.

[0005] In order to realize the above -mentioned purpose, the utility model provides a full tab big cylindrical battery, including roll core, positive pole current collector disc and negative pole current collector disc, one end of roll core is kneaded flat and forms positive pole full tab, the other end of roll core is kneaded flat and forms negative pole full tab, the positive pole current collector disc includes the base body and the connecting piece of connecting the base body and the integral molding with the base body, the base body is provided with a plurality of interval positive pole welding area, and the positive pole full tab is welded on the positive pole welding area, and the connecting piece is bent and leads out the positive pole of battery, and the negative pole current collector disc is provided with a plurality of interval negative pole welding area, and the negative pole full tab is welded on the negative pole welding area.

[0006] In a preferred embodiment, the base body includes a lower surface close to the roll core and an upper surface opposite to the lower surface, the upper surface is provided with a plurality of recesses to form the positive pole welding area, and the lower surface of the positive pole welding area is welded and connected with the positive pole full tab.

[0007] In a preferred embodiment, the base body is circular arc-shaped, the positive pole welding area is rectangular, and a plurality of positive pole welding areas are arranged along the radial direction of the base body and surround the center of the base body.

[0008] In a preferred embodiment, a through hole is formed between the adjacent positive electrode welding areas, and the through hole is circular.

[0009] In a preferred embodiment, the base body is 3 / 4 circular arc-shaped, the connecting piece is rectangular, and the two ends of the circular arc edge of the base body extend to each other to form two transition edges, and the connecting piece connects the transition edges.

[0010] In a preferred embodiment, a notch is formed at the position where the connecting piece is connected to the transition edge.

[0011] In a preferred embodiment, a plurality of semicircular connecting openings are formed at the edge of the connecting piece, and a plurality of circular connecting holes are formed at the middle position of the connecting piece.

[0012] In a preferred embodiment, the negative electrode current collector disc is circular, the negative electrode welding area is rectangular, a plurality of negative electrode welding areas are arranged along the radial direction of the negative electrode current collector disc and surround the center of the negative electrode current collector disc, a through hole is formed between the adjacent negative electrode welding areas, and the through hole is circular.

[0013] In a preferred embodiment, a through hole is formed at the center of the base body, and a circular concave surface is arranged at the center of the negative electrode current collector disc.

[0014] In a preferred embodiment, a cylindrical steel shell with an open end and a cap arranged at the open end of the steel shell are further included, the winding core, the positive electrode current collector disc, and the negative electrode current collector disc are accommodated in the steel shell, the connecting piece of the positive electrode current collector disc is welded to the cap, and the negative electrode current collector disc is welded to the bottom surface of the steel shell.

[0015] Compared with the prior art, the full-tab large cylindrical battery provided by the utility model has the following advantages: one end of the winding core is flattened to form a positive electrode full tab, the other end of the winding core is flattened to form a negative electrode full tab, the positive electrode current collector disc includes a base body and a connecting piece connected to the base body and integrally formed with the base body, the base body is provided with a plurality of spaced positive electrode welding areas, the positive electrode full tab is welded to the positive electrode welding area, the connecting piece is bent to lead out the positive electrode of the battery, the negative electrode current collector disc is provided with a plurality of spaced negative electrode welding areas, and the negative electrode full tab is welded to the negative electrode welding area. Through the design that the full tab is flattened and the full tab is welded to the welding area of the positive electrode current collector disc and the negative electrode current collector disc, the welding area is increased, the problems of virtual welding of the tabs or welding through of the tabs due to the stacking of multiple tabs and insufficient welding strength are avoided, the strength of the current collector disc and the fixing strength of the winding core are enhanced, the flow area is increased, and the capacity and the cycle performance of the battery are improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the premise of the drawings.

[0017] Figure 1 The structure diagram of the full-tab large cylindrical battery provided by the present application is shown in the figure.

[0018] Figure 2 The structure diagram of the positive current collector disc in the full-tab large cylindrical battery provided by the present application is shown in the figure.

[0019] Figure 3 The structure diagram of the negative current collector disc in the full-tab large cylindrical battery provided by the present application is shown in the figure.

CONCRETE IMPLEMENTING METHOD

[0020] The technical scheme of the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application, and obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0021] Please refer to Figure 1 , which is the structure diagram of the full-tab large cylindrical battery 100 provided by the present application. The full-tab large cylindrical battery 100 provided by the present application adopts the full-tab rubbing and current collector disc mode instead of the multi-tab stacking and welding mode, and the design of the positive current collector disc and the negative current collector disc can increase the welding area, avoid the problems of tab virtual welding or tab welding through due to the stacking of multiple tabs and insufficient welding strength, and further improve the battery rate performance and cycle life.

[0022] Please refer to Figure 2 and Figure 3 , the full-tab large cylindrical battery 100 includes a winding core 10, a positive current collector disc 20 and a negative current collector disc 30.

[0023] The one end of the winding core 10 is flattened to form a positive full tab 11, the other end of the winding core 10 is flattened to form a negative full tab 12, the positive current collector 20 includes a base 21 and a connecting piece 22 connected with the base 21 and integrally formed with the base 21, the base 21 is provided with a plurality of spaced positive welding areas 211, the positive full tab 11 is welded on the positive welding area 211, the connecting piece 22 is bent to lead out the positive electrode of the battery, and the negative current collector 30 is provided with a plurality of spaced negative welding areas 301, and the negative full tab 12 is welded on the negative welding area 301.

[0024] Specifically, the winding core 10 is formed by winding the positive plate, the separator and the negative plate, the positive plate is divided into a positive coating area and a positive reserved area, the positive coating area is coated with positive slurry, and the positive reserved area is not coated with slurry, the negative plate is divided into a negative coating area and a negative reserved area, the negative coating area is coated with negative slurry, and the negative reserved area is not coated with slurry, the positive plate, the separator and the negative plate are stacked and wound to form the winding core 10, the positive coating area is opposite to the negative coating area, and the positive reserved area and the negative reserved area are located at the two ends of the winding core, the positive reserved area and the negative reserved area are flattened to form the positive full tab 11 and the negative full tab 12, the positive full tab 11 is welded and connected with the positive current collector 20, and the negative full tab 12 is welded and connected with the negative current collector 30, the positive and negative full tabs and the current collectors are used to replace the multi-tab stacking and welding mode, so as to increase the welding area, avoid the problems of tab virtual welding and tab welding caused by insufficient welding strength due to the stacking of multiple tabs, and greatly increase the current path and the battery power, thereby greatly improving the battery power rate performance and cycle life.

[0025] The positive current collector 20 is a pure aluminum foil, the base 21 includes a lower surface 212 close to the winding core 10 and an upper surface 213 opposite to the lower surface 212, the upper surface 213 is provided with a plurality of recesses to form the positive welding areas 211, and the lower surface of the positive welding area 211 is welded and connected with the positive full tab 11.

[0026] Specifically, the base 21 is a circular arc, the positive welding areas 211 are rectangular, a plurality of positive welding areas 211 are arranged along the radial direction of the base 21 and surround the center of the base 21, and the length of the long side of the positive welding area is 0.6-0.7 times the radius of the base, so that the position and shape of the positive welding area can maximize the welding area and facilitate tab welding.

[0027] Further, through holes 214 are provided between adjacent positive electrode welding areas 211, the through holes 214 are circular, the number of through holes 214 is multiple, the length of the long side of the positive electrode welding area 211 is 3-4 times the diameter of the through hole 214, and the through hole 214 with appropriate size is provided between the positive electrode welding area 211, which can make the electrolyte flow faster in the liquid injection process, and improve the liquid injection efficiency. The center of the base 21 is provided with a through center hole 215, the design of the center hole 215 can facilitate the electrolyte to flow in the liquid injection process, and can facilitate the subsequent negative electrode current collector and the steel shell spot welding of the battery.

[0028] In the embodiment, the base 21 is a 3 / 4 circular arc, the connecting piece 22 is a rectangle, the two ends of the circular arc edge of the base 21 extend in the direction of approaching each other to form two transition edges 216, and the connecting piece 22 connects the transition edges 216. Specifically, a notch 217 is provided at the position where the connecting piece 22 is connected to the transition edge 216, and the notch 217 is circular arc-shaped. Specifically, a plurality of semicircular connecting openings 221 are provided at the edge of the connecting piece 22, and a plurality of circular connecting holes 222 are provided at the middle position of the connecting piece 22, and the design of the notch 217, the connecting opening 221 and the connecting hole 222 can improve the stress of the tab after welding and bending, and prevent the tab from breaking. The base 21 is designed as a 3 / 4 circular arc, and the connecting piece 22 is connected through the transition edge 216, which can increase the flow area, enhance the strength of the current collector and the strength of the fixed battery, increase the welding area, and avoid the problems of tab virtual welding or tab welding caused by insufficient welding strength due to multiple tabs overlapping.

[0029] In actual application, the positive electrode current collector is designed as a total length of 78mm, including the base 21 and the connecting piece 22, the base and the tab are pure aluminum foil: the base 21 is a 3 / 4 large circular arc with a radius of 20mm, wherein the center hole 215 at the center of the large circular arc base is a circular hollow design with a diameter of 6.3mm, the main design idea is to facilitate the electrolyte to flow in the liquid injection process and the welding of the negative electrode current collector, the center of the through hole 214 is on a virtual circle with a diameter of 28mm, which is a circular hollow design with a diameter of 4.0mm, and the circular hollow design on the virtual circle is also to make the electrolyte flow faster in the liquid injection process, the positive electrode welding area 211 is a rectangular solid concave design with a length of 13mm and a width of 5mm, which is mainly designed to weld the positive electrode current collector on the full-tab battery; the connecting piece 22 is a rectangular structure with a length of 46mm and a width of 18mm extending from the center of the circular cross section of the base 21, which is designed with a small circle (i.e. notch 217) with a radius of 1.5mm and a semicircle (i.e. connecting opening 221) with a radius of 1.5mm away from the base 27mm, which is mainly designed to improve the stress of the cap and the tab after welding and bending, and prevent the tab from breaking.

[0030] The negative current collector 30 is made of pure copper or pure nickel material or copper-nickel material, the negative current collector 30 is circular, the negative welding area 301 is rectangular, a plurality of negative welding areas 301 are arranged along the radial direction of the negative current collector 30 and surround the center of the negative current collector 30, a through hole 302 is arranged between adjacent negative welding areas 301, the through hole 302 is circular, and the center of the negative current collector 30 is provided with a circular concave surface 303. The position and shape of the negative welding area 301 can maximize the welding area, which is beneficial to the welding of the tab.

[0031] In actual application, the negative current collector 30 is made of pure copper or pure nickel material or copper-nickel material as a base body, and has a circular design structure with a diameter of 45 mm. The circular concave surface 303 is a concave small circle with a diameter of 8 mm at the center of the circular structure. This design is mainly to connect the combination of the full-tab battery cell and the negative current collector with the steel shell through ultrasonic welding. The center of the through hole 302 is on a circular virtual circle with a diameter of 32 mm, and the through hole 302 is a circular hollow design with a diameter of 5.0 mm. The negative welding area 301 is a rectangular solid concave surface design with a length of 14.5 mm and a width of 5 mm. The through hole 302 and the negative welding area 301 are arranged alternately on the negative current collector. The design of the negative welding area 301 is mainly to weld the negative current collector on the full-tab battery cell.

[0032] The full-tab large cylindrical battery also comprises a cylindrical steel shell with one open end and a cap arranged at the open end of the steel shell. The roll core 10, the positive current collector 20 and the negative current collector 30 are accommodated in the steel shell. The connecting sheet 22 of the positive current collector 20 is welded to the cap, and the negative current collector 30 is welded to the bottom surface of the steel shell. The diameter of the steel shell can be 46 mm. The size of the roll core matches the steel shell. The full-tab large cylindrical battery has the advantages of large capacity, high energy density, easy grouping and the like.

[0033] In actual application, the preparation of the full-tab large cylindrical battery comprises the following steps: preparation of a full-tab roll core, battery assembly and battery formation.

[0034] The preparation of the full-tab roll core comprises the following steps: preparing qualified slurry from preferred positive and negative electrode materials, coating in a stripe coating manner, rolling in a rolling machine, transferring the rolled roll core to a slitting process to divide the roll core into four small roll cores, and then cutting the small positive and negative electrode roll cores in a sheet-making and winding integrated machine. When the sheet-making and winding integrated machine is started, the process parameters need to be adjusted according to the actual production situation on site, such as the shape and specific size of the tab, the total length of the positive electrode sheet, the total length of the negative electrode sheet, the full-tab flattening force, the winding pre-winding tension and winding tension setting, the winding speed and the like.

[0035] The battery assembly is to weld the full tab flattened battery cell with the positive and negative current collectors, then put into the shell and ultrasonic weld the negative current collector to the bottom of the steel shell, and then weld the positive tab to the cap after the steel shell is rolled.

[0036] The battery formation and distribution is to roast the assembled battery cell, inject electrolyte, seal, and then perform formation and distribution on the finished battery.

[0037] According to the full tab large cylindrical battery of the present application, the full tab rubbing, positive and negative current collector process design is selected, which can not only prevent the problems of tab virtual welding or tab welding through due to insufficient welding strength, but also has lower resistance of the prepared tab and higher capacity retention rate of the prepared battery cell.

[0038] According to the full tab battery of the present application, the design of full tab rubbing, positive and negative current collector improves the current-carrying area of the positive and negative tabs, and significantly improves the capacity and cycle performance of the battery.

[0039] The performance of the full tab large cylindrical battery provided by the present application is tested as follows:

[0040] Comparative example:

[0041] The preparation of the multi-tab winding core is to prepare qualified slurry from the selected positive and negative materials, coat in the stripe coating mode, roll in the rolling machine after winding, and then transfer the rolled tab to the slitting process to cut into four small tabs. Then, the cut positive and negative small tabs are sent to the tab welding machine for tab welding. Then, the tab-welded tab is transferred to the winding process for winding.

[0042] The battery assembly is to assemble the full tab flattened battery cell into the positive and negative gaskets, then put into the shell and ultrasonic weld the tab to the bottom of the steel shell, and then weld the positive tab to the cap after the steel shell is rolled.

[0043] The battery formation and distribution is to roast the assembled battery cell, inject electrolyte, seal, and then perform formation and distribution on the finished battery.

[0044] Example:

[0045] The preparation of the full tab roll core is that the positive and negative electrode materials are prepared into qualified slurry, then coated by stripe coating, the roll core is sent to the roller press for rolling, then the rolled roll core is sent to the slitting process for cutting into four small roll cores, then the cut positive and negative electrode small roll cores are sent to the sheet making and winding integrated machine for full tab cutting and cell winding. When starting the sheet making and winding integrated machine, the process parameters need to be adjusted on site according to the actual production situation, such as determining the shape and specific size of the tab, the total length of the positive electrode sheet, the total length of the negative electrode sheet, the full tab flattening force, the winding pre-winding tension and winding tension setting, the winding speed and the like.

[0046] The battery assembly is that the wound and full tab flattened cell is welded with the positive and negative current collecting discs in the application, then the negative current collecting disc is ultrasonically welded to the bottom of the steel shell, after the steel shell is rolled, the tab of the positive current collecting disc extending out is welded with the cap.

[0047] The battery formation and capacity distribution is that the assembled cell is baked, electrolyte is injected, sealed, and then the finished battery is formed and distributed.

[0048] As can be seen from the above, the comparative example and the example use the same positive and negative electrode materials and other auxiliary materials, except that the subsequent production process is different, other requirements are consistent. As shown in Table 1, Table 1 is a part of battery performance comparison table of the batteries prepared by the comparative example and the example.

[0049] Table 1

[0050]

[0051] As can be seen from Table 1, from the comparative example and the example, the capacity retention rate of the full tab large cylindrical battery of the example can reach more than 95% after 600 cycles, and has excellent performance. The full tab large cylindrical battery in the example has an internal resistance of 0.2 mΩ lower than that of the multi-tab large cylindrical battery in the comparative example, and the capacity is nearly 300 mAh higher than that of the multi-tab battery, and the cycle performance of the full tab large cylindrical battery is also better than that of the multi-tab large cylindrical battery, which shows that the full tab battery not only does not have the problems of insufficient welding strength, tab virtual welding or tab welding, but also has larger current conducting area, better heat dissipation effect and performance.

[0052] In conclusion, the full-tab large cylindrical battery 100 provided by the utility model, one end of the roll core 10 is rubbed flat to form a positive full-tab 11, the other end of the roll core 10 is rubbed flat to form a negative full-tab 12, the positive current collector 20 comprises a base 21 and a connecting sheet 22 connected with the base 21 and integrally formed with the base 21, the base 21 is provided with a plurality of spaced positive welding areas 211, the positive full-tab 11 is welded on the positive welding area 211, the connecting sheet 22 is bent to lead out the positive electrode of the battery, the negative current collector 30 is provided with a plurality of spaced negative welding areas 301, the negative full-tab 12 is welded on the negative welding area 301, through the design that the full-tab is rubbed flat and the full-tab is welded with the welding areas of the positive current collector and the negative current collector, the welding area is increased, the problems such as that the full-tabs are virtually welded or the full-tabs are welded through due to the stacking of multiple full-tabs and insufficient welding strength are avoided, the strength of the current collector and the fixing strength of the roll core are enhanced, the flow area is increased, and the capacity and the cycle performance of the battery are improved.

[0053] The above is only the embodiment of the utility model, and does not limit the patent range of the utility model, and equivalent structures or equivalent process transformations using the contents of the utility model specification and drawings or directly or indirectly applied in other related technical fields are also included in the patent protection range of the utility model.

Claims

1. A full tabbed large cylindrical battery, characterized by, The application relates to a battery, which comprises a winding core, a positive electrode current collector and a negative electrode current collector; one end of the winding core is flattened to form a positive electrode full tab, the other end of the winding core is flattened to form a negative electrode full tab, the positive electrode current collector comprises a base body and a connecting sheet connected to the base body and integrally formed with the base body, the base body is provided with a plurality of spaced positive electrode welding areas, the positive electrode full tab is welded on the positive electrode welding area, the connecting sheet is bent to lead out the positive electrode of the battery, and the negative electrode current collector is provided with a plurality of spaced negative electrode welding areas, and the negative electrode full tab is welded on the negative electrode welding area.

2. The full-ledge large cylindrical battery of claim 1, wherein, The base body comprises a lower surface close to the winding core and an upper surface opposite to the lower surface, the upper surface is provided with a plurality of recesses to form the positive electrode welding areas, and the lower surfaces of the positive electrode welding areas are welded and connected with the positive electrode full tab.

3. The full-ledge large cylindrical battery of claim 1, wherein, The base body is in a circular arc shape, the positive electrode welding areas are in a rectangular shape, a plurality of the positive electrode welding areas are arranged along the radial direction of the base body and surround the center of the base body.

4. The full-ledge large cylindrical battery of claim 1, wherein, Through holes are arranged between adjacent positive electrode welding areas, and the through holes are in a circular shape.

5. The full-ledge large cylindrical battery of claim 1, wherein, The base body is in a 3 / 4 circular arc shape, the connecting sheet is in a rectangular shape, the two ends of the circular arc edge of the base body extend to the direction of approaching each other to form two transition edges, and the connecting sheet is connected with the transition edges.

6. The full-ledge large cylindrical battery of claim 5, wherein, Notches are arranged at the positions where the connecting sheet is connected with the transition edges.

7. The full-ledge large cylindrical battery of claim 1, wherein A plurality of semicircular connecting openings are arranged at the edges of the connecting sheet, and a plurality of circular connecting holes are arranged at the middle positions of the connecting sheet.

8. The full-ledge large cylindrical battery of claim 1, wherein, The negative electrode current collector is in a circular shape, the negative electrode welding areas are in a rectangular shape, a plurality of the negative electrode welding areas are arranged along the radial direction of the negative electrode current collector and surround the center of the negative electrode current collector, through holes are arranged between adjacent negative electrode welding areas, and the through holes are in a circular shape.

9. The full-ledge large cylindrical battery of claim 1, wherein, A through center hole is arranged at the center of the base body, and the center of the negative electrode current collector is provided with a circular concave surface.

10. The full-ledge large cylindrical battery according to any one of claims 1 to 9, wherein The application further relates to a cylindrical steel shell with one open end and a cap arranged at the open end of the steel shell, the winding core, the positive electrode current collector and the negative electrode current collector are accommodated in the steel shell, the connecting sheet of the positive electrode current collector is welded and connected with the cap, and the negative electrode current collector is welded and connected with the bottom surface of the steel shell.

Images