A lithium battery with a novel tab structure and a manufacturing method thereof

Abstract

The present invention discloses a lithium battery with a novel tab structure and a manufacturing method thereof, comprising a bare battery cell formed by stacking positive electrode sheets, a separator and negative electrode sheets; the positive tabs of the positive electrode sheets and the negative tabs of the negative electrode sheets are stacked alternately and evenly distributed around the bare battery cell; and there is a preset angle between adjacent positive electrode sheets and negative electrode sheets, and the sum of the preset angles is 360°; the multiple positive tabs constitute a positive tab group; the multiple negative tabs constitute a negative tab group; the positive tab group is folded on the first surface of the bare battery cell, and the negative tab group is folded on the second surface opposite to the first surface of the bare battery cell; the positive tab group is welded to the positive collector sheet, and the negative tab group is welded to the negative collector sheet; the positive collector sheet and the positive electrode shell, as well as the negative collector sheet and the negative electrode shell are fixedly connected by butt welding; the present invention can improve the energy density of the lithium battery, reduce the difficulty of welding, and improve the product qualification rate.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a lithium battery with a novel tab structure and a manufacturing method thereof. Background Art

[0002] Currently, lithium batteries mainly include wound batteries and laminated batteries. Wound batteries occupy most of the 3C consumer market due to their advantages such as high manufacturing efficiency, good consistency and easy cost control. Compared with laminated batteries, although wound batteries have core competitiveness in terms of manufacturing costs, they have low energy density, high internal resistance, and are easy to deform during the cycle, resulting in deterioration of electrochemical performance and even safety accidents. With the rapid expansion and development of the lithium battery application market, higher requirements are placed on lithium batteries. Lithium batteries with lighter weight, thinner thickness, longer battery life, faster charging and higher output power are in urgent need of development. However, wound batteries are difficult to meet the requirements, and laminated batteries with higher energy density, lower internal resistance and longer cycle life are increasingly favored by the market.

[0003] The laminated battery adopts positive electrode sheets and negative electrode sheets stacked on each other, a positive electrode tab is provided at one end of the positive electrode sheet, and the positive electrode tabs on the positive electrode sheet form a positive electrode tab group in the same direction, a negative electrode tab is provided at one end of the negative electrode sheet, and the negative electrode tabs on the negative electrode sheet form a negative electrode tab group in the other direction, and then the positive electrode tab group and the negative electrode tab group are pre-welded and cut, and finally welded to the positive electrode collector sheet and the negative electrode collector sheet respectively. For steel shell batteries, the positive electrode collector sheet needs to be welded to the positive electrode shell, and the negative electrode collector sheet needs to be welded to the negative electrode shell. The manufacturing process is extremely complicated, and since the tab group contains several tabs, welding is difficult, and it is easy to have problems such as cold welding and over-welding, and the quality is difficult to control. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects in the prior art and provide a lithium battery with a new type of tab structure and a manufacturing method thereof, which can improve the energy density of the lithium battery, reduce the difficulty of the manufacturing process, reduce the difficulty of welding, and is less likely to cause cold welding, over-welding, etc., making it easy to control the quality and improving the product qualification rate.

[0005] To achieve the above-mentioned objectives, the present invention provides a lithium battery with a novel tab structure, including a bare cell, wherein the bare cell is formed by stacking a positive electrode sheet, a separator and a negative electrode sheet; the positive electrode sheet is provided with a positive electrode tab; the negative electrode sheet is provided with a negative electrode tab; the positive electrode sheet and the negative electrode sheet are stacked alternately; the positive electrode tabs and the negative electrode tabs are evenly distributed around the bare cell; and there is a preset angle between adjacent positive electrode tabs and negative electrode tabs, and the sum of the preset angles is 360°; the multiple positive electrode tabs constitute a positive electrode tab group; the multiple negative electrode tabs constitute a negative electrode tab group; the positive electrode tab group is folded on the first surface of the bare cell, and the negative electrode tab group is folded on the second surface opposite to the first surface of the bare cell; the positive electrode tab group is welded to the positive electrode collector sheet, and the negative electrode tab group is welded to the negative electrode collector sheet; the positive electrode collector sheet and the positive electrode shell, and the negative electrode collector sheet and the negative electrode shell are fixedly connected by butt welding.

[0006] Preferably, the number of positive electrode tabs in the same angular direction in the positive electrode tab group is between 1 and 5; the number of negative electrode tabs in the same angular direction in the negative electrode tab group is between 1 and 5; the number of tabs welded at one time is greatly reduced, thereby avoiding centralized welding of all positive electrode tabs or negative electrode tabs.

[0007] Preferably, the bare battery cell includes N positive pole pieces and N-1 negative pole pieces; or N positive pole pieces and N negative pole pieces; or N positive pole pieces and N+1 negative pole pieces; wherein the value range of N is between 2 and 50.

[0008] Preferably, the bare battery cell includes the same number or different numbers of positive electrode sheets and negative electrode sheets, and the number of the positive electrode sheets is greater than or equal to 2.

[0009] Preferably, the diaphragm is a base membrane made of a polypropylene material component or a polyethylene material component, and its surface is coated with one or more coatings selected from ceramic, boehmite non-metallic layer, polyvinylidene fluoride, and polymethyl methacrylate adhesive layer.

[0010] Preferably, the positive electrode current collector is made of aluminum with a thickness of less than 2 mm; the negative electrode current collector is made of copper or nickel with a thickness of less than 2 mm.

[0011] Preferably, the positive electrode shell and the negative electrode shell are made of steel material components or aluminum material components, and are made into steel shell lithium batteries or aluminum shell lithium batteries.

[0012] Preferably, the main body shape of the positive electrode sheet and the negative electrode sheet is circular; the positive electrode sheet is coated with a positive electrode coating layer; the negative electrode sheet is coated with a negative electrode coating layer; the negative electrode coating layer completely covers the positive electrode coating layer; the shape of the diaphragm is circular, and the diaphragm completely covers the negative electrode coating layer; a circular lithium battery is made, and the diameter of the circular lithium battery does not exceed 30 mm.

[0013] The present invention also provides a method for manufacturing a lithium battery having a novel tab structure as described above, comprising the following steps:

[0014] Step S1: manufacturing a positive electrode sheet, a separator and a negative electrode sheet for stacking into a bare battery cell; the positive electrode sheet is provided with a positive electrode tab; the negative electrode sheet is provided with a negative electrode tab;

[0015] Step S2: stacking the positive electrode sheets, separators, and negative electrode sheets alternately in sequence; the positive electrode tabs and negative electrode tabs are evenly distributed around the bare battery cell; and there is a preset angle between adjacent positive electrode tabs and negative electrode tabs, and the sum of the preset angles is 360°;

[0016] Step S3: assemble a plurality of positive electrode tabs into a positive electrode tab group, and assemble a plurality of negative electrode tabs into a negative electrode tab group;

[0017] Folding the positive electrode tab group onto the first surface of the bare cell, and folding the negative electrode tab group onto the second surface opposite to the first surface of the bare cell;

[0018] Step S4: Welding the positive electrode tab group to the positive electrode collector sheet, and welding the negative electrode tab group to the negative electrode collector sheet;

[0019] Step S5: After the welding is completed, the bare cell containing the positive electrode collector sheet and the negative electrode collector sheet is placed between the positive electrode shell and the negative electrode shell, and the bare cell is baked and injected with liquid; the positive electrode collector sheet and the positive electrode shell, and the negative electrode collector sheet and the negative electrode shell are fixedly connected together by butt welding.

[0020] Preferably, in step S3, the positive electrode tab group and the negative electrode tab group are finely cut or trimmed to ensure that the positive electrode tab group and the negative electrode tab group are evenly spaced after being folded to avoid overlapping.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The bare cell of the present invention is formed by stacking a positive electrode sheet, a separator and a negative electrode sheet; forming a stacked or laminated battery, which has a higher energy density than a wound battery and can improve the energy density of the lithium battery.

[0023] 2. The present invention stacks the positive electrode sheets and the negative electrode sheets in an interlaced manner; the positive electrode tabs and the negative electrode tabs are evenly distributed around the bare battery cell; and there is a preset angle between adjacent positive electrode tabs and negative electrode tabs, and the sum of the preset angles is 360°; at this time, the positive electrode tabs and the negative electrode tabs form a new type of tab structure; the new type of tab structure is not an improvement on the structure of the tabs, but an improvement on the arrangement structure of the tabs; by adopting the above-mentioned new type of tab structure, the positive electrode tabs and the negative electrode tabs are arranged at all positions on the circumference of the bare battery cell, and the positive electrode tabs and the negative electrode tabs are dispersedly arranged, so that all the positive electrode tabs or the negative electrode tabs can be avoided from being welded together; this can greatly reduce the number of tabs welded at one time, reduce the difficulty of welding, and also reduce the difficulty of the manufacturing process. The tabs are welded on the circumference of the collector sheet, so that the welds are evenly distributed, and it is not easy to have cold welding, over-welding, etc., the quality is easy to control, and the product qualification rate is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 is a top view of a bare battery cell provided by the present invention;

[0026] Figure 2 This is a schematic diagram of the exploded structure of a lithium battery with a novel tab structure provided by the present invention.

[0027] Included in the diagram are:

[0028] 1-positive electrode shell, 2-negative electrode shell, 3-positive electrode collector, 4-negative electrode collector, 501-positive electrode sheet, 503-diaphragm, 502-negative electrode sheet, 504-positive electrode tab, 505-negative electrode tab. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solution in this embodiment of the present invention in conjunction with the drawings in this embodiment of the present invention. Obviously, the embodiment described is only one embodiment of the present invention, not all embodiments of the present invention. Based on this embodiment of the present invention, all other embodiments of the present invention obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] Example 1

[0031] Please refer to Figure 1and Figure 2 , Embodiment 1 of the present invention provides a lithium battery with a novel tab structure.

[0032] like Figure 2 As shown, the lithium battery includes a bare cell, which is installed in the middle of the lithium battery. Figure 2 As shown, the bare cell includes a positive electrode sheet 501, a separator 503 and a negative electrode sheet 502; the positive electrode sheet 501, the separator 503 and the negative electrode sheet 502 are stacked on each other to form a bare cell; the stacked or laminated lithium battery has a higher energy density than the wound lithium battery, which can improve the energy density of the lithium battery.

[0033] Specifically, such as Figure 2 As shown, the main body shape of the positive electrode sheet 501 and the negative electrode sheet 502 is circular; the circular positive electrode sheet 501 is welded with a rectangular strip of positive electrode tab 504 along the diameter direction, and similarly, the circular negative electrode sheet 502 is welded with a rectangular strip of negative electrode tab 505 along the diameter direction. Furthermore, the positive electrode sheet 501 is coated with a positive electrode coating layer; the negative electrode sheet 502 is coated with a negative electrode coating layer; generally, the shape and size of the positive electrode sheet 501 and the negative electrode sheet 502 are the same, and the negative electrode coating layer completely covers the positive electrode coating layer; as shown Figure 1 As shown, the shape of the diaphragm 503 is also circular, as shown in FIG. Figure 2 As shown, the separator 503 completely covers the positive electrode coating layer and the negative electrode coating layer; a circular lithium battery is made, and the diameter of the circular lithium battery does not exceed 30 mm.

[0034] Furthermore, in this embodiment, only the embodiment in which the main shape of the positive electrode plate 501 and the negative electrode plate 502 is circular is cited. According to the above discussion, the main shape can also be changed to an ellipse, a square, a rectangle or other quadrilaterals or polygons according to actual production conditions. Similarly, the positive electrode tab 504 and the negative electrode tab 505 can also be other shapes; they can be freely selected according to actual conditions, and this patent does not limit them.

[0035] like Figure 2 As shown, the positive electrode sheets 501 and the negative electrode sheets 502 are stacked alternately; Figure 1As shown, the positive electrode tab 504 and the negative electrode tab 505 are evenly distributed around the bare battery cell; and there is a preset angle between adjacent positive electrode tabs 504 and negative electrode tabs 505, and the sum of the preset angles is 360°; at this time, the positive electrode tab 504 and the negative electrode tab 505 form a new type of tab structure; the new type of tab structure is not an improvement on the structure of the tab, but an improvement on the arrangement structure of the tab; by adopting the above-mentioned new type of tab structure, the positive electrode tab 504 and the negative electrode tab 505 are dispersed, so that the number of welds can be greatly reduced in one welding.

[0036] Specifically, adopt the above arrangement, such as Figure 1 As shown, the circumference of the bare battery cell is distributed with positive pole tabs 504 or negative pole tabs 505 along the diameter direction; the positive pole tabs 504 and the negative pole tabs 505 are dispersedly arranged, rather than all the positive pole tabs 504 in one direction and all the negative pole tabs 505 in one direction, so as to avoid centralized welding of all the positive pole tabs 504 or negative pole tabs 505; the positive pole tabs 504 and the negative pole tabs 505 are respectively welded on the circumference of the positive collector 3 and the negative collector 4, which extends the welding area, thereby greatly reducing the number of pole tabs welded at one time, so as to avoid centralized welding of all the positive pole tabs 504 or negative pole tabs 505; the difficulty of welding is reduced, and the difficulty of the manufacturing process is also reduced. The pole tabs are respectively welded on the circumference of the collector, so that the welds are evenly distributed, and it is not easy to have cold welding, over-welding, etc., the quality is easy to control, and the product qualification rate is improved.

[0037] Furthermore, since there is more than one positive electrode sheet 501 and negative electrode sheet 502, there are multiple positive electrode tabs 504 and multiple negative electrode tabs 505, and the several positive electrode tabs 504 constitute a positive electrode tab group; the several negative electrode tabs 505 constitute a negative electrode tab group; according to the above-mentioned bare battery cell is a cylinder, it has two upper and lower surfaces, the upper surface is the first surface, and the lower surface is the second surface; the positive electrode tab group is folded on the first surface of the bare battery cell, and the negative electrode tab group is folded on the second surface opposite to the first surface of the bare battery cell; the positive electrode tab group and the negative electrode tab group are separated, the positive electrode tab group is welded on the positive collector sheet 3, and the negative electrode tab group is welded on the negative collector sheet 4; specifically, the positive collector sheet 3 is an aluminum material component with a thickness of less than 2 mm; the negative collector sheet 4 is a copper material component or a nickel material component with a thickness of less than 2 mm.

[0038] Furthermore, the positive electrode collector sheet 3 and the positive electrode shell 1, and the negative electrode collector sheet 4 and the negative electrode shell 2 are fixedly connected by butt welding; the positive electrode shell 1 and the negative electrode shell 2 are steel material components or aluminum material components, and are made into steel shell lithium batteries or aluminum shell lithium batteries.

[0039] In this embodiment, if Figure 1 and 2 As shown, there is one positive electrode tab 504 at the same angular direction in the positive electrode tab group; there is also one negative electrode tab 505 at the same angular direction in the negative electrode tab group; this greatly reduces the number of tabs welded at one time, thereby avoiding centralized welding of all positive electrode tabs 504 or negative electrode tabs 505; further, the number of positive electrode tabs 504 at the same angular direction in the positive electrode tab group is between 1 and 5; the number of negative electrode tabs 505 at the same angular direction in the negative electrode tab group is between 1 and 5.

[0040] As an embodiment, the bare battery cell includes N positive electrode sheets 501 and N-1 negative electrode sheets 502; or N positive electrode sheets 501 and N negative electrode sheets 502; or N positive electrode sheets 501 and N+1 negative electrode sheets 502; where the value range of N is between 2 and 50.

[0041] As another embodiment, the bare cell includes the same number or different numbers of positive electrode sheets 501 and negative electrode sheets 502 , and the number of the positive electrode sheets 501 is greater than or equal to 2.

[0042] The diaphragm 503 is a base membrane made of polypropylene or polyethylene, and its surface is coated with one or more coatings selected from ceramic, boehmite non-metallic layer, polyvinylidene fluoride, and polymethyl methacrylate adhesive layer.

[0043] Example 2

[0044] Please refer to Figure 1 and Figure 2 , Embodiment 2 of the present invention provides a method for manufacturing a lithium battery containing a novel tab structure as described in Embodiment 1, comprising the following steps.

[0045] Step S1: respectively manufacture a positive electrode sheet 501, a separator 503 and a negative electrode sheet 502 for stacking into a bare cell; the positive electrode sheet 501 is provided with a positive electrode tab 504; the negative electrode sheet 502 is provided with a negative electrode tab 505.

[0046] Step S2: The positive electrode sheet 501, the diaphragm 503 and the negative electrode sheet 502 are stacked alternately in sequence; the positive electrode tabs 504 and the negative electrode tabs 505 are evenly distributed around the bare battery cell; and there is a preset angle between adjacent positive electrode tabs 504 and negative electrode tabs 505, and the sum of the preset angles is 360°; at this time, the positive electrode tabs 504 and the negative electrode tabs 505 form a new type of tab structure; the new type of tab structure is not an improvement on the structure of the tab, but an improvement on the arrangement structure of the tab; the above-mentioned new type of tab structure is used to disperse the positive electrode tabs 504 and the negative electrode tabs 505, so that the number of welds can be greatly reduced in one welding.

[0047] Step S3: multiple positive electrode tabs 504 are formed into a positive electrode tab group, and multiple negative electrode tabs 505 are formed into a negative electrode tab group; the positive electrode tab group is folded on the first surface of the bare battery cell, and the negative electrode tab group is folded on the second surface opposite to the first surface of the bare battery cell; the positive electrode tab group and the negative electrode tab group are isolated to prevent them from causing contact short circuit.

[0048] Furthermore, in step S3, the positive electrode tab group and the negative electrode tab group are finely cut or trimmed to ensure that the positive electrode tab group and the negative electrode tab group are evenly spaced after being folded to avoid overlapping.

[0049] Step S4: Weld the positive electrode tab group to the positive electrode collector sheet 3, and weld the negative electrode tab group to the negative electrode collector sheet 4.

[0050] Step S5: After the welding is completed, the bare battery cell containing the positive electrode collector sheet 3 and the negative electrode collector sheet 4 is placed between the positive electrode shell 1 and the negative electrode shell 2, and the bare battery cell is baked and injected with liquid; the positive electrode collector sheet 3 and the positive electrode shell 1, and the negative electrode collector sheet 4 and the negative electrode shell 2 are fixedly connected together by butt welding.

[0051] Example 3

[0052] Please refer to Figure 1 and Figure 2 , embodiment three of the present invention provides a specific method for manufacturing embodiment one.

[0053] The specific implementation method is described in detail below.

[0054] like Figure 2 As shown, the positive electrode slurry is coated on the positive electrode collector made of an aluminum foil material component to produce a positive electrode roll; the negative electrode slurry is coated on the negative electrode collector made of a copper foil material component to produce a negative electrode roll.

[0055] The positive electrode coil is punched into a positive electrode sheet 501 equipped with a positive electrode tab 504 and a circular positive electrode coating layer; the negative electrode coil is punched into a negative electrode sheet 502 equipped with a negative electrode tab 505 and a circular negative electrode coating layer.

[0056] The diameter of the negative electrode coating layer is greater than that of the positive electrode coating layer; the negative electrode coating layer completely covers the positive electrode coating layer; and the edge width margin of the negative electrode coating layer is 1 mm.

[0057] The separator 503 is also pre-punched into a circular sheet. The separator 503 completely covers the negative electrode coating layer. The edge width margin of the separator 503 is 1 mm.

[0058] The positive electrode sheet 501, the separator 503 and the negative electrode sheet 502 are stacked alternately in sequence; the positive electrode tabs 504 and the negative electrode tabs 505 are evenly distributed around the bare battery cell; and there is a preset angle between adjacent positive electrode tabs 504 and negative electrode tabs 505, and the sum of the preset angles is 360°; at this time, the positive electrode tabs 504 and the negative electrode tabs 505 form a new type of tab structure; the new type of tab structure is not an improvement on the structure of the tabs, but an improvement on the arrangement structure of the tabs; using the above-mentioned new type of tab structure, the positive electrode tabs 504 and the negative electrode tabs 505 are dispersed, so that the number of welds can be greatly reduced in one welding.

[0059] After the positive electrode sheet 501 and the negative electrode sheet 502 are stacked, Figure 1 As shown, the angle between the adjacent positive electrode tabs 504 and negative electrode tabs 505 is 45°.

[0060] like Figure 2 As shown, there is only one positive electrode tab 504 in the same angular direction in the positive electrode tab group; and there is also only one negative electrode tab 505 in the same angular direction in the negative electrode tab group.

[0061] The positive electrode tab group and the negative electrode tab group are precisely cut or trimmed to ensure that the positive electrode tab group and the negative electrode tab group are evenly spaced after folding to avoid overlapping.

[0062] like Figure 2 As shown, the positive electrode tab group is folded onto the first surface of the bare cell, that is, the upper surface of the bare cell, and the positive electrode tab group is welded to the positive electrode collector 3; the negative electrode tab group is folded onto the second surface opposite to the first surface of the bare cell, that is, the lower surface of the bare cell, and the negative electrode tab group is welded to the negative electrode collector 4.

[0063] The bare battery cell with the novel tab structure is placed between the positive electrode shell 1 and the negative electrode shell 2, and the bare battery cell is baked and injected with liquid; the positive electrode collector 3 and the positive electrode shell 1, and the negative electrode collector 4 and the negative electrode shell 2 are fixedly connected together by butt welding.

[0064] Finally, a circular lithium battery with a new type of tab structure was obtained.

[0065] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A lithium battery with a novel tab structure, characterized in that: The invention comprises a bare battery cell, wherein the bare battery cell is formed by stacking a positive electrode sheet (501), a separator (503) and a negative electrode sheet (502); the positive electrode sheet (501) is provided with a positive electrode tab (504); the negative electrode sheet (502) is provided with a negative electrode tab (505); the positive electrode tab (504) and the negative electrode tab (505) are stacked alternately; the positive electrode sheet (501) and the negative electrode sheet (502) are evenly distributed around the bare battery cell; and there is a preset angle between adjacent positive electrode tabs (504) and negative electrode tabs (505). The sum of the preset angles is 360°; the plurality of positive electrode tabs (504) form a positive electrode tab group; the plurality of negative electrode tabs (505) form a negative electrode tab group; the positive electrode tab group is folded on the first surface of the bare battery cell, and the negative electrode tab group is folded on the second surface opposite to the first surface of the bare battery cell; the positive electrode tab group is welded to the positive electrode collector sheet (3), and the negative electrode tab group is welded to the negative electrode collector sheet (4); the positive electrode collector sheet (3) and the positive electrode shell (1), and the negative electrode collector sheet (4) and the negative electrode shell (2) are fixedly connected by butt welding; The number of positive electrode tabs (504) in the same angular direction in the positive electrode tab group is between 1 and 5; the number of negative electrode tabs (505) in the same angular direction in the negative electrode tab group is between 1 and 5; The main body shapes of the positive electrode plate (501) and the negative electrode plate (502) are circular; the shape of the diaphragm (503) is circular; the circular positive electrode plate (501) is welded with a rectangular strip positive electrode tab (504) along the diameter direction; and the circular negative electrode plate (502) is welded with a rectangular strip negative electrode tab (505) along the diameter direction; The circumference of the bare battery cell is distributed with positive electrode tabs (504) and negative electrode tabs (505) along the diameter direction; the positive electrode tabs (504) and negative electrode tabs (505) are dispersedly arranged; the positive electrode tabs (504) and negative electrode tabs (505) are respectively welded to the circumference of the positive electrode collector sheet (3) and the negative electrode collector sheet (4), thereby extending the welding area.

2. A lithium battery with a novel tab structure according to claim 1, characterized in that: The positive electrode plate (501) is coated with a positive electrode coating layer; the negative electrode plate (502) is coated with a negative electrode coating layer; the negative electrode coating layer completely covers the positive electrode coating layer; the separator (503) completely covers the negative electrode coating layer; the angle between the adjacent positive electrode tabs (504) and negative electrode tabs (505) is 45 degrees, and a circular lithium battery is manufactured, and the diameter of the circular lithium battery does not exceed 30 mm.

3. A lithium battery with a novel tab structure according to claim 1, characterized in that: The bare battery cell comprises N positive electrode sheets (501) and N-1 negative electrode sheets (502); or N positive electrode sheets (501) and N negative electrode sheets (502); or N positive electrode sheets (501) and N+1 negative electrode sheets (502); wherein the value of N ranges from 2 to 50.

4. A lithium battery with a novel tab structure according to claim 1, characterized in that: The bare battery cell comprises the same number or different numbers of positive electrode sheets (501) and negative electrode sheets (502), and the number of the positive electrode sheets (501) is greater than or equal to 2.

5. A lithium battery with a novel tab structure according to claim 1, characterized in that: The diaphragm (503) is a polypropylene material component or a polyethylene material component as a base membrane, and its surface is coated with one or more coatings selected from ceramic, boehmite non-metallic layer, polyvinylidene fluoride, and polymethyl methacrylate adhesive layer.

6. A lithium battery with a novel tab structure according to claim 1, characterized in that: The positive electrode current collector (3) is an aluminum material component with a thickness of less than 2 mm; the negative electrode current collector (4) is a copper material component or a nickel material component with a thickness of less than 2 mm.

7. A lithium battery with a novel tab structure according to claim 1, characterized in that: The positive electrode shell (1) and the negative electrode shell (2) are steel material components or aluminum material components, and are made into a steel shell lithium battery or an aluminum shell lithium battery.

8. A method for manufacturing a lithium battery having a novel tab structure according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step S1; A positive electrode sheet (501), a separator (503), and a negative electrode sheet (502) for stacking into a bare battery cell are manufactured; the positive electrode sheet (501) is provided with a positive electrode tab (504); and the negative electrode sheet (502) is provided with a negative electrode tab (505); Step S2: stacking the positive electrode sheet (501), the separator (503) and the negative electrode sheet (502) alternately in sequence; the positive electrode tabs (504) and the negative electrode tabs (505) are evenly distributed around the bare battery cell; and there is a preset angle between adjacent positive electrode tabs (504) and negative electrode tabs (505), and the sum of the preset angles is 360°; Step S3: assembling a plurality of positive electrode tabs (504) into a positive electrode tab group, and assembling a plurality of negative electrode tabs (505) into a negative electrode tab group; Folding the positive electrode tab group onto the first surface of the bare cell, and folding the negative electrode tab group onto the second surface opposite to the first surface of the bare cell; Step S4: welding the positive electrode tab group to the positive electrode current collector (3), and welding the negative electrode tab group to the negative electrode current collector (4); Step S5: The bare battery cell containing the positive electrode collector sheet (3) and the negative electrode collector sheet (4) after welding is placed between the positive electrode shell (1) and the negative electrode shell (2), and the bare battery cell is baked and injected with liquid; the positive electrode collector sheet (3) and the positive electrode shell (1), and the negative electrode collector sheet (4) and the negative electrode shell (2) are fixedly connected together by butt welding.

9. The method for manufacturing a lithium battery with a novel tab structure according to claim 8, characterized in that: In step S3, the positive electrode tab group and the negative electrode tab group are finely cut or trimmed to ensure that the positive electrode tab group and the negative electrode tab group are evenly spaced after being folded to avoid overlapping.

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