Full-tab cylindrical battery cell and manufacturing process thereof

Abstract

The invention discloses a full-tab cylindrical battery cell and a manufacturing process thereof, the battery cell comprises a roll core, the roll core is provided with two process surfaces, each process surface is uniformly distributed with a flattening area and a non-flattening area, the non-flattening area comprises a first non-flattening area and a second non-flattening area, and the first non-flattening area and the second non-flattening area are arranged on the roll core. The first non-kneading area, the kneading area and the second non-kneading area are sequentially arranged from the center direction of the roll core to the periphery, the first non-kneading area, the second non-kneading area and the process face are located in the same plane, and the kneading area is higher than the process face. Therefore, only the rubbing area is rubbed during rubbing, so that the technical problems that the foil on the innermost side and the foil on the outermost side of the roll core of the existing full-tab cylindrical battery core are easy to turn over, and the foils are tightly attached to each other, so that the liquid injection and infiltration time is long, and the production efficiency is relatively low are fundamentally solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cylindrical batteries, and in particular to a full-ear cylindrical battery cell and a manufacturing process thereof. Background Art

[0002] At present, large cylindrical cells basically adopt a full-ear structure design in order to improve rate performance, reduce internal resistance and heat generation. The main manufacturing process of full-ear cylindrical cells is to flatten the foil at both ends of the manufactured core, and then weld them to the collector plate on the cover plate, and then weld the shell and the cover plate around it, and finally inject liquid, form and seal to obtain the finished cell. However, when the cell with this design structure is flattened, the innermost and outermost foils of the core may flip toward the center hole of the core and the outer periphery of the core, so that the foil is not pressed tightly against the two end faces of the core, resulting in certain safety risks for the manufactured cell. At the same time, the foils at both ends of the rolled core of the battery cell with this design structure are tightly fitted together due to extrusion after being flattened. Therefore, during the injection process, multiple positive / negative pressure alternating injections are required, resulting in a long injection time. The electrolyte can only gradually penetrate and infiltrate the electrode from the center hole of the core in the shell, resulting in a long infiltration time, which seriously affects the production efficiency. Multiple injections will also affect the consistency of the battery cell. Summary of the invention

[0003] The purpose of the present invention is to propose a full-tab cylindrical battery cell and its manufacturing process, which is intended to solve the technical problems of the existing full-tab cylindrical battery cell, that the innermost foil and the outermost foil of the winding core are easy to flip, the injection and immersion time are long, and the production efficiency is low.

[0004] In order to achieve the above technical objectives, the present invention is implemented through the following technical solutions: In a first aspect, the present invention provides a full-ear cylindrical battery cell, including a winding core, wherein the winding core has two process surfaces, each of which is distributed with a flattened area and a non-flattened area, the non-flattened area includes a first non-flattened area and a second non-flattened area, the first non-flattened area, the flattened area and the second non-flattened area are arranged in sequence from the center direction of the winding core to the periphery, the first non-flattened area and the second non-flattened area are in the same plane as the process surface, and the flattened area is higher than the process surface.

[0005] In some embodiments, the area of ​​the non-flattened zone accounts for 1% to 50% of the area of ​​the process surface.

[0006] In some embodiments, the winding core includes a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and the negative electrode sheet are stacked, and the two end surfaces of the positive electrode sheet and the negative electrode sheet after winding form the two process surfaces of the winding core.

[0007] In some embodiments, uncoated areas are formed at both ends of the positive electrode sheet and the negative electrode sheet in the unfolded state, and the uncoated areas at each end are respectively recessed toward the center direction of the positive electrode sheet or the negative electrode sheet to form a first notch and a second notch, wherein the first notch constitutes the first non-flattened area of ​​the positive electrode sheet and the negative electrode sheet after winding, and the second notch constitutes the second non-flattened area of ​​the positive electrode sheet and the negative electrode sheet after winding.

[0008] In some embodiments, the first notch and the second notch are of equal length.

[0009] In some embodiments, the first notch and the second notch have the same height.

[0010] In a second aspect, the present invention provides a manufacturing process for manufacturing the full-ear cylindrical battery cell provided in the first aspect of the present invention, comprising the following steps: S1, making positive electrode sheet and negative electrode sheet; S2, cutting off the uncoated areas at both ends of the positive electrode sheet and the negative electrode sheet from the two side edges toward the center to form a first notch and a second notch; S3, stacking the positive electrode sheet and the negative electrode sheet and winding them to form a winding core, wherein the first notch forms a first non-flattened area, the second notch forms a second non-flattened area, and the uncut portion in the middle forms a flattened area; S4, performing a flattening operation on the flattening area of ​​the winding core.

[0011] In some embodiments, the first non-flattening area and the second non-flattening area constitute the non-flattening area of ​​the core, and the areas of the two non-flattening areas respectively account for 1% to 50% of the area of ​​the process surfaces at both ends of the core.

[0012] In some embodiments, the cutting lengths of the first notch and the second notch are equal.

[0013] In some embodiments, the cutting heights of the first notch and the second notch are equal.

[0014] Compared with the prior art, the present invention provides a full-ear cylindrical battery cell, and the uncoated areas at both ends of the positive and negative electrodes are cut off during production, so that after the positive and negative electrodes are wound, a first non-kneaded area and a second non-kneaded area can be formed, and the uncut middle part forms a raised kneaded area compared with the first non-kneaded area and the second non-kneaded area. Then, during the kneading process, only the raised kneaded area is kneaded, while the first non-kneaded area near the center of the core and the second non-kneaded area outside the core do not need to be kneaded, which fundamentally solves the flipping problem of the foil near the center position and the periphery of the core in the prior art, and improves the safety of the finished battery cell. At the same time, since the first non-kneaded area and the second non-kneaded area are not kneaded, the foil is not squeezed, and the electrolyte can quickly infiltrate the inside of the core from the periphery of the two end surfaces of the core and the position near the center hole, which greatly improves the injection efficiency and accelerates the infiltration of the electrolyte inside the core, improves the injection efficiency, reduces the number of injections, and makes the consistency of the battery cell more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the full-ear cylindrical battery cell of the present invention; Figure 2 It is a cross-sectional expansion diagram of the full-ear cylindrical battery cell of the present invention; Figure 3 is an expanded view of the positive electrode sheet of the present invention (the negative electrode sheet is the same as the positive electrode sheet); Figure 4 It is a process flow chart of the manufacturing process of the full-ear cylindrical battery cell of the present invention.

[0016] As shown in the figure: 100, winding core, 110, positive electrode sheet, 111, first notch, 112, second notch, 101, flattening area, 102, non-flattening area, 102a, first non-flattening area, 102b second non-flattening area. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] At present, when the large cylindrical battery cells with full-tab tabs are flattened, the innermost and outermost foils of the core are easy to flip toward the center hole of the core and the periphery of the core, which makes the battery cells have certain safety risks; and the foils at both ends of the flattened core will be squeezed and tightly fitted together, resulting in long injection and infiltration time, which in turn affects the injection efficiency of the battery cells.

[0019] In view of the above two technical problems, the present invention proposes a full-ear cylindrical battery cell and its manufacturing process, which can well solve the above two technical problems. Figures 1 to 3 As shown, the first aspect of the present invention provides a full-ear cylindrical battery cell, including a winding core 100, which is cylindrical, and has two process surfaces at both ends of the cylindrical length direction, each of which is distributed with a flattening area 101 and a non-flattening area 102, and the non-flattening area 102 includes a first non-flattening area 102a and a second non-flattening area 102b, and the first non-flattening area 102a, the flattening area 101 and the second non-flattening area 102b are arranged in sequence from the center direction of the winding core 100 to the periphery, and the first non-flattening area 102a and the second non-flattening area 102b are in the same plane as the process surface, and the flattening area 101 is higher than the process surface.

[0020] The full-ear cylindrical battery cell provided by the present invention is configured by setting the process surface as a flattening area 101 and a non-flattening area 102, and the flattening area 101 is higher than the process surface, and the non-flattening area 102 is in the same plane as the process surface. In this way, during the flattening process, only the higher flattening area 101 is flattened, while the first non-flattening area 102a near the center hole of the core 100 and the second non-flattening area 102b outside the core 100 are not flattened, which fundamentally solves the flipping problem of the foil near the center position and the periphery of the core in the prior art, and improves the safety of the finished battery cell. At the same time, since the first non-flattening area 102a and the second non-flattening area 102b are not flattened, the foil is not squeezed, and the electrolyte can quickly infiltrate the inside of the core from the periphery of the two end surfaces of the core and the position near the center hole, which greatly improves the injection efficiency and accelerates the infiltration of the electrolyte inside the core, improves the injection efficiency, reduces the number of injections, and makes the consistency of the battery cell more stable.

[0021] In addition, when the present invention is welded with the current collecting plate of the cover plate after flattening, the welding area is concentrated in the flattening area 101, and the flattening area 101 is higher than the process surface. Therefore, the present invention is conducive to subsequent clamping and welding with the current collecting plate.

[0022] In one embodiment, the area of ​​the non-flattened area 102 accounts for 1% to 50% of the area of ​​the process surface.

[0023] In one embodiment, the winding core 100 is a cylindrical structure formed by winding the positive electrode sheet 110 and the negative electrode sheet (the structure of the negative electrode sheet is the same as that of the positive electrode sheet) and the diaphragm, and the two end surfaces of the cylindrical structure form the two process surfaces of the winding core 100.

[0024] In one embodiment, if Figure 3As shown, uncoated areas are formed at both ends of the positive electrode sheet 110 and the negative electrode sheet in the unfolded state, and the uncoated areas at each end are respectively recessed toward the center direction of the positive electrode sheet 110 or the negative electrode sheet to form a first notch 111 and a second notch 112, wherein the first notch 111 constitutes a first non-flattened area 102a of the positive electrode sheet 110 and the negative electrode sheet after winding, and the second notch 112 constitutes a second non-flattened area 102b of the positive electrode sheet 110 and the negative electrode sheet after winding.

[0025] In one embodiment, the first notch 111 and the second notch 112 are of equal length.

[0026] In one embodiment, the first notch 111 and the second notch 112 have the same height.

[0027] That is, the areas of the first non-flattened area 102 a formed by the first notch 111 and the second non-flattened area 102 b formed by the second notch 112 are equal.

[0028] Second, as Figure 4 As shown, the present invention further provides a manufacturing process, which is used to manufacture the full-ear cylindrical battery cell provided by the first aspect of the present invention, comprising the following steps: Step S1, manufacturing a positive electrode sheet 110 and a negative electrode sheet; Specifically, the manufacturing process of the positive electrode sheet 110 is as follows: active materials, conductive agents, binders, etc. are added to a solution in a certain proportion, stirred evenly, and a slurry is then evenly coated on a positive electrode current collector (usually an aluminum foil), the coated positive electrode sheet 110 is dried to remove the solvent, the dried positive electrode sheet 110 is compacted by a roller press, and then the positive electrode sheet 110 is cut into required sizes.

[0029] In this step, both ends of the positive electrode sheet 110 are left with uncoated areas.

[0030] It can be understood that the manufacturing process of the negative electrode sheet is basically the same as that of the positive electrode sheet.

[0031] Step S2, the uncoated areas at both ends of the positive electrode sheet 110 and the negative electrode sheet are cut away from both side edges toward the center to form a first notch 111 and a second notch 112; Specifically, the cutting lengths and cutting heights of the first notch 111 and the second notch 112 are equal, that is, the areas of the first non-flattened zone 102a and the second non-flattened zone 102b formed by the first notch 111 and the second notch 112 are equal; the formed first non-flattened zone 102a and the second non-flattened zone 102b constitute the non-flattened zone 102 of the core 100 of the present invention, and the area of ​​the non-flattened zone 102 accounts for 1% to 50% of the area of ​​the process surface at one end of the core 100.

[0032] Step S3, stacking the positive electrode sheet 110, the negative electrode sheet and the separator and winding them to form a winding core 100, wherein the first notch 111 forms a first non-flattened area 102a, the second notch 112 forms a second non-flattened area 102b, and the uncut portion in the middle forms a flattened area 101; S4, performing a flattening operation on the flattening area 101 of the winding core 100.

[0033] After flattening, the winding core 100 is welded to the current collecting plate of the cover plate, and the welding area is concentrated in the flattening area 101 higher than the process surface, while the non-flattening area in the same plane as the process surface does not need to be welded.

[0034] In summary, during the production of a full-ear cylindrical battery cell provided by the present invention, the uncoated areas at both ends of the positive electrode sheet 110 and the negative electrode sheet are cut off, so that a first non-flattened area 102a and a second non-flattened area 102b can be formed after the positive electrode sheet 110 and the negative electrode sheet are wound, and the middle uncut part forms a flattened area 101 that is raised compared with the first non-flattened area and the second non-flattened area. Then, during the flattening process, only the flattened area 101 of the raised part is flattened, while the first non-flattened area 102a near the center of the core 100 and the second non-flattened area 102b outside the core 100 do not need to be flattened, which fundamentally solves the problem of flipping of the foil near the center position and the periphery of the core in the prior art, and improves the safety of the finished battery cell. At the same time, since the first non-flattened area 102a and the second non-flattened area 102b are not flattened, the foil is not squeezed, and the electrolyte can quickly infiltrate the inside of the core 100 from the periphery of the two end surfaces of the core 100 and the position near the center hole, which greatly improves the injection efficiency and speeds up the infiltration of the electrolyte into the inside of the core, improves the injection efficiency, reduces the number of injections, and makes the consistency of the battery cell more stable.

[0035] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A full-ear cylindrical battery cell, characterized in that: It includes a winding core, which has two process surfaces, each of which is distributed with a flattening area and a non-flattening area, the non-flattening area includes a first non-flattening area and a second non-flattening area, the first non-flattening area, the flattening area and the second non-flattening area are arranged in sequence from the center direction of the winding core to the periphery, the first non-flattening area and the second non-flattening area are in the same plane as the process surface, and the flattening area is higher than the process surface.

2. The full-ear cylindrical battery cell according to claim 1, characterized in that: The area of ​​the non-flattened zone accounts for 1% to 50% of the area of ​​the process surface.

3. The full-ear cylindrical battery cell according to claim 2, characterized in that: The winding core comprises a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and the negative electrode sheet are stacked, and two end surfaces of the positive electrode sheet and the negative electrode sheet after winding form the two process surfaces of the winding core.

4. The full-ear cylindrical battery cell according to claim 3, characterized in that: Both ends of the positive electrode sheet and the negative electrode sheet in the unfolded state are formed with uncoated areas, and the uncoated areas at each end are respectively recessed toward the center direction of the positive electrode sheet or the negative electrode sheet to form a first notch and a second notch, wherein the first notch constitutes a first non-flattened area of ​​the positive electrode sheet and the negative electrode sheet after winding, and the second notch constitutes a second non-flattened area of ​​the positive electrode sheet and the negative electrode sheet after winding.

5. The full-ear cylindrical battery cell according to claim 4, characterized in that: The first notch and the second notch have the same length.

6. The full-ear cylindrical battery cell according to claim 5, characterized in that: The first notch and the second notch have the same height.

7. A manufacturing process for manufacturing the full-ear cylindrical battery cell according to any one of claims 1 to 6, characterized in that: The manufacturing process comprises the following steps: S1, making positive electrode sheet and negative electrode sheet; S2, cutting off the uncoated areas at both ends of the positive electrode sheet and the negative electrode sheet from the two side edges toward the center to form a first notch and a second notch; S3, stacking the positive electrode sheet and the negative electrode sheet and winding them to form a winding core, wherein the first notch forms a first non-flattened area, the second notch forms a second non-flattened area, and the uncut portion in the middle forms a flattened area; S4, performing a flattening operation on the flattening area of ​​the winding core.

8. The manufacturing process according to claim 7, characterized in that: The first non-flattening area and the second non-flattening area constitute the non-flattening area of ​​the winding core, and the areas of the two non-flattening areas respectively account for 1% to 50% of the areas of the process surfaces at both ends of the winding core.

9. The manufacturing process according to claim 8, characterized in that: The cutting lengths of the first notch and the second notch are equal.

10. The manufacturing process according to claim 9, characterized in that: The cutting heights of the first notch and the second notch are equal.

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