Wound bean battery

Abstract

The present invention discloses a wound bean-shaped battery, comprising a bottom shell and a cap, a space for accommodating a wound cell is formed between the bottom shell and the cap, one pole ear of the wound cell is connected to the cap, and the other pole ear is connected to the bottom shell, the bottom shell comprises a bottom plate and a first surrounding wall arranged around one side of the bottom plate, the cap comprises a top plate and a second surrounding wall arranged around one side of the top plate, the second surrounding wall is sleeved outside the first surrounding wall, a plurality of continuous first arc-shaped portions are arranged on the first surrounding wall along its axial direction, a plurality of second arc-shaped portions cooperating with the first arc-shaped portions are arranged on the second surrounding wall along its axial direction, and a sealing member is sandwiched between the first surrounding wall and the second surrounding wall; the pole piece of the wound cell is in the shape of a long strip, when one pole ear is arranged on the pole piece, it is arranged at the center of the length direction of the pole piece, and when at least two pole ears are arranged on the pole piece, they are arranged at intervals along the length direction of the pole piece. The wound bean-shaped battery of the present invention has a simple structure, good sealing effect, and can realize fast charging and high-rate discharge.

Description

Technical Field

[0001] The invention relates to the technical field of batteries, and in particular to a wound bean-shaped battery. Background Art

[0002] A button battery, also known as a button cell, refers to a battery with an appearance like a small button. A button battery generally includes a bottom shell, a cap, and a battery cell disposed in a receiving cavity formed by the bottom shell and the cap. Since the size of a button battery is very small, it is very difficult to seal it. The assembly process of a button battery is as follows: a sealing ring is placed on the bottom shell, and after placing the battery cell and other operations, the cap is placed on the bottom shell for sealing. Although existing button batteries contain sealing rings, their sealing effect is still average, which can easily lead to battery leakage and affect the service life of the button battery. In addition, the sealing ring is also prone to damage during sealing, resulting in sealing failure.

[0003] In addition, the tabs of conventional wound button batteries are all located at the ends of the pole pieces, which causes the current button batteries to have shortcomings in fast charging and high-rate discharge performance. Summary of the invention

[0004] An object of an embodiment of the present invention is to provide a wound bean-shaped battery with a simple structure and good sealing effect.

[0005] Another object of an embodiment of the present invention is to provide a wound bean-type battery that can achieve fast charging and high-rate discharge performance.

[0006] To achieve this purpose, the embodiment of the present invention adopts the following technical solutions:

[0007] Provided is a wound bean-shaped battery, comprising a bottom shell and a cap, wherein a space for accommodating a wound battery cell is formed between the bottom shell and the cap, wherein one pole ear of the wound battery cell is connected to the cap, and the other pole ear is connected to the bottom shell, wherein the bottom shell comprises a bottom plate and a first surrounding wall arranged around a side surface of the bottom plate, wherein the cap comprises a top plate and a second surrounding wall arranged around a side surface of the top plate, wherein the second surrounding wall is sleeved outside the first surrounding wall, wherein the first surrounding wall is provided with a plurality of continuous first arc-shaped portions along its axial direction, wherein the second surrounding wall is provided with a plurality of second arc-shaped portions cooperating with the first arc-shaped portions along its axial direction, and wherein a sealing member is sandwiched between the first surrounding wall and the second surrounding wall;

[0008] The pole piece of the wound battery cell is in the shape of an elongated strip. When one pole ear is provided on the pole piece, the pole ear is provided at the center position of the length direction of the pole piece. When at least two pole ears are provided on the pole piece, at least two pole ears are provided at intervals along the length direction of the pole piece, and the pole ears extend to the outside of the wound battery cell.

[0009] As a preferred solution of the wound bean-type battery, the first arc-shaped portion is annularly arranged on the first surrounding wall, and a plurality of the first arc-shaped portions are parallel along the axis direction of the first surrounding wall; or,

[0010] A plurality of the first arc-shaped portions are spirally wound on the first surrounding wall along the axis direction of the first surrounding wall; or,

[0011] The first arc-shaped portion includes a plurality of sub-arc-shaped portions annularly spaced apart from each other along the circumference of the first surrounding wall.

[0012] As a preferred solution of the wound bean-type battery, the first arc-shaped portion is formed by stamping or rolling the first surrounding wall, and the second arc-shaped portion is formed by stamping or rolling the second surrounding wall.

[0013] As a preferred solution of the wound bean-shaped battery, all the first arc-shaped portions are convexly arranged toward the center of the first surrounding wall, and all the second arc-shaped portions are convexly arranged toward the center of the second surrounding wall; or,

[0014] All of the first arc-shaped portions are convexly disposed away from the center of the first surrounding wall, and all of the second arc-shaped portions are convexly disposed away from the center of the second surrounding wall; or,

[0015] The protruding directions of two adjacent first arc-shaped portions on the first surrounding wall are opposite, and a plurality of the first arc-shaped portions form a first wave-shaped structure on the first surrounding wall, and a plurality of the second arc-shaped portions on the second surrounding wall form a second wave-shaped structure matching the first wave-shaped structure.

[0016] As a preferred solution of the wound bean-type battery, the hardness of the first surrounding wall is greater than the hardness of the second surrounding wall.

[0017] As a preferred solution of the wound bean-type battery, a constricted portion is formed at one end of the second surrounding wall away from the top plate, and an end of the constricted portion is pressed against an outer wall of the first surrounding wall or an outer wall of the bottom plate; or,

[0018] One end of the second surrounding wall away from the top plate is pressed against the outer wall of the first surrounding wall; or,

[0019] A curling structure is disposed at one end of the second surrounding wall away from the top plate, and the curling structure is tightly pressed against the outer wall of the first surrounding wall.

[0020] As a preferred solution of the wound bean-type battery, the seal includes a sealing body sandwiched between the first surrounding wall and the second surrounding wall, the sealing body has a first extension portion extending toward the center of the sealing body from one end close to the top plate, the first extension portion has a second extension portion extending toward the bottom plate from one end away from the sealing body, and the second extension portion is tightly attached to the inner wall of the first surrounding wall.

[0021] As a preferred solution of the wound bean-shaped battery, the bottom shell and the cover cap are both made of metal material.

[0022] As a preferred solution of the wound bean-type battery, the pole piece includes a current collector and an active material coated on the current collector, and the pole ear is integrally formed with the current collector; or,

[0023] The current collector is provided with an empty foil area which is not coated with the active material, one end of the pole ear is welded to the empty foil area, and the other end extends to the outside of the wound battery cell.

[0024] As a preferred solution of the wound bean-type battery, when at least two pole ears are provided on the pole piece, one of the pole ears is located at the center of the length direction of the pole piece, and the remaining pole ears are spaced apart from the pole ear located at the center of the length direction of the pole piece.

[0025] As a preferred solution of the wound bean-type battery, at least two and an odd number of the pole ears are arranged on the pole piece, one of the pole ears is located at the center of the length direction of the pole piece, and the remaining pole ears are symmetrically arranged relative to the center of the length direction of the pole piece.

[0026] As a preferred solution of a wound bean-type battery, the wound battery cell includes a positive electrode sheet, a negative electrode sheet and a separator arranged between the positive electrode sheet and the negative electrode sheet, the separator has an isolating portion extending along the axial direction of the wound battery cell to both ends of the negative electrode sheet, and the isolating portion is used to isolate the electrode ear of the wound battery cell from the end face of the wound battery cell.

[0027] The beneficial effects of the embodiments of the present invention are as follows: by arranging corresponding arc-shaped portions on the first surrounding wall and the second surrounding wall, the arrangement of the arc-shaped portions can press the seal between the first surrounding wall and the second surrounding wall, thereby significantly improving the sealing between the bottom shell and the cap, and the arrangement of the arc-shaped portions can also protect the seal, thereby preventing the seal from being damaged when the cap is sealed, thereby extending the service life of the seal and ensuring that the seal between the bottom shell and the cap does not fail; by arranging a single pole ear at the center position of the length direction of the pole piece of the wound battery cell, or arranging a plurality of pole ears at intervals on the pole piece, the wound bean-type battery can meet the requirements of fast charging and high-rate discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is further described in detail below based on the accompanying drawings and embodiments.

[0029] Figure 1 FIG. 4 is a cross-sectional schematic diagram of a wound bean-shaped battery according to an embodiment of the present invention.

[0030] Figure 2 for Figure 1 Schematic diagram of the decomposition.

[0031] Figure 3 FIG. 4 is a cross-sectional schematic diagram of a wound bean-shaped battery according to another embodiment of the present invention.

[0032] Figure 4 for Figure 3 Schematic diagram of the decomposition.

[0033] Figure 5 FIG. 4 is a cross-sectional schematic diagram of a wound bean-shaped battery according to another embodiment of the present invention.

[0034] Figure 6 for Figure 5 Schematic diagram of the decomposition.

[0035] Figure 7 FIG. 4 is a cross-sectional schematic diagram of a wound bean-shaped battery according to another embodiment of the present invention.

[0036] Figure 8 FIG. 4 is a cross-sectional schematic diagram of a wound bean-shaped battery according to another embodiment of the present invention.

[0037] Fig. 9 It is a schematic diagram of the structure of a pole piece and a pole ear according to an embodiment of the present invention.

[0038] Fig.10 It is a schematic structural diagram of a pole piece and a pole ear according to another embodiment of the present invention.

[0039] Fig.11 It is a schematic structural diagram of a pole piece and a pole ear in an unfolded state according to an embodiment of the present invention.

[0040] Fig.12 It is a schematic structural diagram of a pole piece and a pole ear in an unfolded state according to another embodiment of the present invention.

[0041] In the figure:

[0042] 1. bottom shell; 11. bottom plate; 12. first surrounding wall; 13. first arc-shaped portion;

[0043] 2. Cover cap; 21. Top plate; 22. Second surrounding wall; 23. Second arc-shaped portion; 24. Curling structure;

[0044] 3. Wound cell; 31. Pole ear; 311. Positive pole ear; 312. Negative pole ear; 32. Extension portion; 321. Overlapping position; 33. Reinforcement member; 34. Pole sheet; 341. Positive pole sheet; 342. Negative pole sheet; 35. Diaphragm; 351. Isolation portion;

[0045] 4. Sealing member; 41. Sealing body; 42. First extension portion; 43. Second extension portion. DETAILED DESCRIPTION

[0046] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0047] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0049] Reference Figures 1 to 6 ,as well as Fig.11As shown, the wound bean-shaped battery disclosed in the present invention comprises a bottom shell 1 and a cap 2, a space for accommodating a wound battery cell 3 is formed between the bottom shell 1 and the cap 2, one pole ear 31 of the wound battery cell 3 is connected to the cap 2, and the other pole ear 31 is connected to the bottom shell 1, the bottom shell 1 comprises a bottom plate 11 and a first surrounding wall 12 arranged around a side of the bottom plate 11, the cap 2 comprises a top plate 21 and a second surrounding wall 22 arranged around a side of the top plate 21, the second surrounding wall 22 is sleeved outside the first surrounding wall 12, and the first surrounding wall 12 is provided with a plurality of continuous first arc portions along its axial direction. 13, a plurality of second arc-shaped portions 23 cooperating with the first arc-shaped portion 13 are arranged on the second surrounding wall 22 along its axial direction, and a seal 4 is sandwiched between the first surrounding wall 12 and the second surrounding wall 22; the pole piece 34 of the wound battery cell 3 is in the shape of an elongated strip, and when one pole ear 31 is arranged on the pole piece 34, the pole ear 31 is arranged at the center position of the length direction of the pole piece 34, and when at least two pole ears 31 are arranged on the pole piece 34, at least two pole ears 31 are arranged at intervals along the length direction of the pole piece 34, and the pole ears 31 extend to the outside of the wound battery cell 3. By arranging corresponding arc portions on the first surrounding wall 12 and the second surrounding wall 22, the arrangement of the arc portions can press the seal 4 between the first surrounding wall 12 and the second surrounding wall 22, and can form a longer sealing reinforcement area in a limited space (the size of the bean-type battery is relatively small, for example: the diameter is 10mm-13mm, and the height is 3mm-6mm) by utilizing the protruding arc portions, thereby effectively improving the sealing between the bottom shell 1 and the cap 2, and the contact position between the arc portion and the seal 4 is an arc surface, which can effectively prevent the seal 4 from contacting with sharp parts, thereby preventing the seal 4 from being damaged when the cap 2 is sealed, extending the service life of the seal 4, and also ensuring that the seal between the bottom shell 1 and the cap 2 does not fail; by arranging a single pole ear 31 at the center of the length direction of the pole piece 34 of the wound battery cell 3, or arranging multiple pole ears 31 at intervals on the pole piece 34, the wound bean-type battery can meet the requirements of fast charging and high-rate discharge.

[0050] The wound battery core 3 may be in a cylindrical, square, or elliptical shape.

[0051] The tabs 31 are not limited to being located at both ends of the wound battery core 3 , but may also be located at the same end of the wound battery core 3 .

[0052] like Figure 1 and Figure 2As shown, in this embodiment, the first arc-shaped portion 13 is annularly arranged on the first surrounding wall 12, and correspondingly, the second arc-shaped portion 23 is also annularly arranged on the second surrounding wall 22. The annularly arranged arc-shaped portion can not only ensure a better sealing effect and effectively prevent leakage, but also reduce the manufacturing difficulty and improve production efficiency. In addition, the arc-shaped portion of this structure has no gap along the first surrounding wall 12 or the second surrounding wall 22, which further enhances the sealing effect.

[0053] In other embodiments, the arc portion is not limited to being set as an integral annular structure, and each arc portion can also be set as an annularly spaced structure, the first arc portion 13 includes a plurality of sub-arc portions arranged at circumferential annular intervals along the first surrounding wall 12, and the positions of the sub-arc portions of two adjacent first arc portions 13 correspond one to one. Correspondingly, the second arc portion 23 also includes a plurality of sub-arc portions arranged at circumferential annular intervals along the second surrounding wall 22, and the positions of the sub-arc portions of two adjacent second arc portions 23 correspond one to one, so that the positions of the first arc portion 13 and the second arc portion 23 can correspond to each other and fit together.

[0054] The sub-arc-shaped portions of each first arc-shaped portion 13 are symmetrically arranged along the central axis of the wound battery core 3 , and the positions of the sub-arc-shaped portions of two adjacent first arc-shaped portions 13 correspond to each other.

[0055] The one-to-one corresponding arrangement means that, in a top-down view, the sub-arc portion of the topmost first arc portion 13 completely blocks the sub-arc portions of the remaining first arc portions 13. In addition, multiple first arc portions 13 can be spirally wound on the first surrounding wall 12 along the axis direction of the first surrounding wall 12, and correspondingly, multiple second arc portions 23 can be spirally wound on the second surrounding wall 22 along the axis direction of the second surrounding wall 22. The spirally wound structure can make the cap 2 screwed on the bottom shell 1, which not only makes the sealing stronger, but also can reduce the wear on the seal 4 by spiral installation, effectively extending the service life of the seal 4.

[0056] In this embodiment, the first arc-shaped portion 13 is formed by stamping or rolling the first surrounding wall 12, and the second arc-shaped portion 23 is formed by stamping or rolling the second surrounding wall 22. Stamping or rolling the arc-shaped portion can not only reduce the manufacturing difficulty, but also form a corresponding groove on the back side of the convex arc-shaped portion, and utilize the groove to accommodate the arc-shaped portion that fits therewith, so as to achieve a close fit.

[0057] In a specific embodiment of the present invention, Figure 1 and 2 As shown, all the first arc-shaped portions 13 are protruded toward the center of the first surrounding wall 12 , and all the second arc-shaped portions 23 are protruded toward the center of the second surrounding wall 22 .

[0058] In another specific embodiment of the present invention, Figure 3 and 4 As shown, all the first arc-shaped portions 13 are convexly disposed away from the center of the first surrounding wall 12 , and all the second arc-shaped portions 23 are convexly disposed away from the center of the second surrounding wall 22 .

[0059] In another specific embodiment of the present invention, Figure 5 and 6 As shown, the convex directions of two adjacent first arc-shaped portions 13 on the first surrounding wall 12 are opposite, and the plurality of first arc-shaped portions 13 form a first wavy structure on the first surrounding wall 12, and the plurality of second arc-shaped portions 23 on the second surrounding wall 22 form a second wavy structure matched with the first wavy structure. The wavy structure can make the first surrounding wall 12 and the second surrounding wall 22 fit more closely and have better sealing.

[0060] In order to ensure that the wound bean-type battery does not deform during assembly and edge sealing, the hardness of the first surrounding wall 12 is set to be greater than the hardness of the second surrounding wall 22. The first surrounding wall 12 has a relatively large hardness and can be used as a supporting substrate. Whether in the steps of assembling the seal 4 and the cap 2 or sealing the cap 2, the first surrounding wall 12 (i.e., the bottom shell 1) will not be deformed or the deformation of the first surrounding wall 12 is much smaller than the deformation of the second surrounding wall 22, thereby ensuring that the appearance and sealing of the wound bean-type battery are not invalid.

[0061] In one embodiment, a constricted portion is formed at one end of the second surrounding wall 22 away from the top plate 21, and the end of the constricted portion is pressed against the outer wall of the first surrounding wall 12. The setting of the constricted portion can effectively prevent the cap 2 from being separated from the bottom shell 1, and can further improve the sealing between the bottom shell 1 and the cap 2.

[0062] Of course, the end of the necked portion is not limited to abutting against the outer wall of the first surrounding wall 12. The second surrounding wall 22 of the cap 2 can also be set to be long enough so that after the cap 2 is assembled on the bottom shell 1, it can extend to the side of the bottom plate 11 away from the first surrounding wall 12, and then the necked portion of the second surrounding wall 22 is necked, and at this time the necked portion is tightly against the outer wall of the bottom plate 11.

[0063] In addition, the end of the second surrounding wall 22 may be directly pressed against the outer wall of the first surrounding wall 12 without forming the necking portion, or Figure 7 As shown, the end of the second surrounding wall 22 away from the top plate 21 is curled to form a curling structure 24 . The curling structure 24 can also improve the sealing between the bottom shell 1 and the cover cap 2 .

[0064] In one embodiment, if Figures 1 to 6As shown, the sealing member 4 includes a sealing body 41 sandwiched between the first surrounding wall 12 and the second surrounding wall 22, and a first extension portion 42 extends from one end of the sealing body 41 close to the top plate 21 toward the center of the sealing body 41, and a second extension portion 43 extends from one end of the first extension portion 42 away from the sealing body 41 toward the bottom plate 11, and the second extension portion 43 is closely attached to the inner wall of the first surrounding wall 12. The sealing body 41 is sandwiched between the first surrounding wall 12 and the second surrounding wall 22. Since the corresponding first arc-shaped portion 13 and second arc-shaped portion 23 are provided on these two surrounding walls, the sealing body 41 is squeezed to form a plurality of concave-convex structures. Since there are concave-convex structures on the sealing body 41, the sealing area can be increased, thereby improving the sealing effect. At the same time, the sealing body 41 of this structure has high air tightness, which can effectively prevent the occurrence of liquid leakage.

[0065] Of course, a third arcuate portion matching the first arcuate portion 13 and the second arcuate portion 23 may be pre-arranged on the seal 4. By providing the third arcuate portion, the seal 4 can be more closely fitted to the first surrounding wall 12 and the second surrounding wall 22, and the sealing performance is better.

[0066] In this embodiment, the third arc portion is disposed on the sealing body 41 .

[0067] In addition, the first extension portion 42 and the second extension portion 43 can cooperate with the sealing body 41 to form a positioning structure for the seal 4. During installation, the upper end of the first surrounding wall 12 is clamped between the second extension portion 43 and the sealing body 41, and the first extension portion 42 is pressed against the end face of the upper end of the first surrounding wall 12 to achieve the positioning of the seal 4.

[0068] The length of the second extension portion 43 along the vertical direction is smaller than the width of a single first arc portion 13 or second arc portion 23 along the vertical direction, so that the second extension portion 43 within the first surrounding wall 12 is shorter, which can reduce material consumption and thus reduce manufacturing costs, while also ensuring basic positioning effects.

[0069] In one embodiment, the bottom shell 1 and the cap 2 are both made of metal material. The bottom shell 1 and the cap 2 made of metal material have high hardness, so that the entire shell of the wound bean-shaped battery is a hard shell. The hard shell structure can ensure that the appearance of the entire wound bean-shaped battery remains unchanged, and can also effectively prevent the shell from being deformed due to inflation in the battery.

[0070] The metal material here can be a single metal material or an alloy material.

[0071] In this embodiment, the metal material is stainless steel.

[0072] In one embodiment, if Figure 1 and Fig.11 As shown, the electrode sheets 34 of the wound battery cell 3 are divided into a positive electrode sheet 341 and a negative electrode sheet 342 . The positive electrode sheet 341 and the negative electrode sheet 342 have similar shapes, both in the shape of long strips. Each electrode sheet 34 includes a current collector and an active material coated on the current collector.

[0073] In this embodiment, only one positive electrode ear 311 is provided on the positive electrode sheet 341, and only one negative electrode ear 312 is provided on the negative electrode sheet 342. The positive electrode ear 311 is located at the center of the length direction of the positive electrode sheet 341, and extends toward the top of the wound battery cell 3 to be connected to the cap 2. The negative electrode ear 312 is located at the center of the length direction of the negative electrode sheet 342, and extends toward the bottom of the wound battery cell 3 to be connected to the bottom shell 1.

[0074] Of course, the number of the pole lugs 31 on the pole piece 34 is not limited to one, but may be two or more. When two or more pole lugs 31 are provided on the pole piece 34, one pole lug 31 is provided at the center of the length direction of the pole piece 34, and the remaining pole lugs 31 are provided at intervals on one side or both sides of the pole lug 31. Fig.12 As shown, taking the example of three pole ears 31 being arranged on each pole piece 34 , one pole ear 31 is arranged at the center position of the pole piece 34 in the length direction, and the remaining two pole ears 31 are symmetrically arranged along the center of the length direction of the pole piece 34 .

[0075] In other embodiments, if at least two pole tabs 31 are disposed on the pole piece 34 , the pole tabs 31 may also be disposed at the ends of the pole piece 34 in the length direction.

[0076] like Figure 1 , Fig. 9 and Fig.10 As shown, when the pole ear 31 is led out from the end of the pole piece 34, the current collector has an extension portion 32 extending to the outside of the active material along the radial direction of the wound battery cell 3, the extension portion 32 is partially overlapped after being bent, the extension portion 32 is arranged at an angle with the pole piece 34, and the extension portion 32 is bent to form the pole ear 31. By extending the extension portion 32 of the current collector of the pole piece 34 to the outside of the active material and bending it to directly form the pole ear 31, the process of welding the pole ear 31 is omitted, the production efficiency is improved, and the internal resistance of the wound battery cell 3 is reduced. At the same time, the pole ear 31 and the pole piece 34 formed in one piece have higher strength and are not easy to separate.

[0077] Preferably, a reinforcing member 33 is provided at the overlapped position 321 of the extension portion 32. By providing an additional reinforcing member 33 at the overlapped position 321 of the extension portion 32, the reinforcing member 33 can strengthen the strength of the bent overlapped position 321, effectively preventing the extension portion 32 from being broken after being bent, protecting the integrity of the tab 31, and also strengthening the overall strength of the tab 31.

[0078] The bending angle of the extension part 32 is flexibly adjusted according to the requirements of the wound battery cell 3 during packaging. Specifically, the extension part 32 is bent at the position connected to the end of the pole piece 34 as a fulcrum, and the first angle α is bent, wherein the first angle α is 90°. This angle can make it easier for the extension part 32 to be led out from both ends of the wound battery cell 3, shorten the length of the pole ear 31, and reduce the manufacturing cost. Of course, the bending angle of the extension part 32 is not limited to 90°, and the first angle α can also be set to 30°, 45°, 100° or 120°, etc. according to needs.

[0079] like Fig. 9 As shown, in a preferred embodiment of the present invention, the reinforcement member 33 is wrapped with tape outside the overlapping position 321 of the extension part 32. The reinforcement member 33 is set as tape. On the one hand, it can buffer the overlapping position 321 of the extension part 32 after bending, and can alleviate the stress of the extension part 32 at the bending part to a certain extent, effectively reducing the phenomenon of the extension part 32 breaking at the overlapping position 321 and causing the pole ear 31 and the pole piece 34 to separate. On the other hand, the tape is used to protect and shape the structure of the overlapping position 321 of the extension part 32, preventing the pole ear 31 from being deformed at the overlapping position 321 of the extension part 32 after long-term use, thereby affecting the normal use of the wound battery cell 3. In order to further enhance the protective effect of the tape on the extension part 32, multiple layers of tape can be wrapped around the overlapping position 321.

[0080] like Fig.10 As shown, in another preferred embodiment of the present invention, the reinforcing member 33 is a double-sided adhesive tape, and a first overlapping surface and a second overlapping surface that are in contact with each other are provided on the extension portion 32 and located at the overlapping position 321, and the double-sided adhesive tape is provided between the first overlapping surface and the second overlapping surface. The provision of the double-sided adhesive tape can effectively prevent the first overlapping surface and the second overlapping surface from being separated, so as to prevent the tab 31 from occupying the space between the bottom shell 1 and the cap 2.

[0081] In addition, the extension portion 32 can be bent multiple times at the same position to increase the thickness of the overlapping position 321 , thereby improving the strength of the pole piece 34 .

[0082] When the pole ear 31 is led out from a non-end position of the pole piece 34 , an extension portion 32 is directly extended from the current collector of the pole piece 34 along the axial direction of the wound battery cell 3 , and the pole ear 31 can be formed without bending.

[0083] In other embodiments, the structure in which the current collector of the pole ear 31 and the pole piece 34 is integrated is not limited. The current collector of the pole ear 31 and the pole piece 34 can also be set as a separate structure. For example, an empty foil area not coated with the active material is provided at a corresponding position on the current collector, one end of the pole ear 31 is welded to the empty foil area, and the other end extends to the outside of the wound battery cell 3.

[0084] In one embodiment, if Figure 8 As shown, a separator 35 is provided between the positive electrode sheet 341 and the negative electrode sheet 342 of the wound battery cell 3, and the separator 35 has a separator 351 extending along the axis direction of the wound battery cell 3 to the two ends of the negative electrode sheet 342, and the separator 351 is used to isolate the pole ear 31 of the wound battery cell 3 from the end face of the wound battery cell 3. The provision of the separator 351 can effectively prevent the pole ear 31 from making electrical contact with the two ends of the wound battery cell 3 in the vertical direction, and there is no need to provide an additional insulating gasket on the end face of the wound battery cell 3, which reduces the difficulty and cost of preparing the wound bean-type battery, improves the production efficiency, and at the same time, there is no need to change the preparation process and equipment of the existing battery, which is conducive to the large-scale production of the wound bean-type battery, and has good insulation.

[0085] In this embodiment, the length of the isolating portion 351 extending from the end surface of the wound battery cell 3 is not less than 0.75 mm. This design can ensure that the end surface of the wound battery cell 3 formed after the positive electrode sheet 341, the negative electrode sheet 342 and the separator 35 are wound has a sufficient length of the isolating portion 351 to insulate the tab 31 and ensure the insulation effect.

[0086] In addition, generally, since the current collector of the positive electrode sheet 341 is aluminum foil, and the current collector of the negative electrode sheet 342 is copper foil, the material of the positive electrode tab 311 is aluminum foil, and the material of the negative electrode tab 312 is copper foil. Both aluminum foil and copper foil are softer than the nickel sheet of the existing tab material, so that the separator 351 is not easily punctured by the tab 31 when attached to the end face of the wound battery cell 3.

[0087] In order to further improve the safety of the wound bean-type battery, a separator having high temperature resistance (130-150° C.) and / or high mechanical strength, such as an aramid separator, may be used.

[0088] The diameter-to-height ratio of the wound bean-shaped battery is ≥1; preferably >1.

[0089] The above-mentioned wound bean-shaped battery is a rechargeable bean-shaped battery.

[0090] In the description of this article, it is necessary to understand that the term "upper" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0091] In the description of this specification, the description of reference term "an embodiment" etc. means that the specific features, structures, materials or characteristics of the embodiment are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment.

[0092] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0093] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A wound bean-shaped battery, comprising a bottom shell and a cap, wherein a space for accommodating a wound battery cell is formed between the bottom shell and the cap, wherein one pole ear of the wound battery cell is connected to the cap, and the other pole ear is connected to the bottom shell, characterized in that: The bottom shell comprises a bottom plate and a first surrounding wall arranged around one side of the bottom plate, the cover cap comprises a top plate and a second surrounding wall arranged around one side of the top plate, the second surrounding wall is sleeved outside the first surrounding wall, a plurality of continuous first arc-shaped portions are arranged on the first surrounding wall along its axial direction, a plurality of second arc-shaped portions cooperating with the first arc-shaped portions are arranged on the second surrounding wall along its axial direction, and a sealing member is sandwiched between the first surrounding wall and the second surrounding wall; The pole piece of the wound battery cell is in the shape of a long strip. When one pole ear is provided on the pole piece, the pole ear is provided at the center of the length direction of the pole piece. When at least two pole ears are provided on the pole piece, at least two pole ears are provided at intervals along the length direction of the pole piece, and the pole ears extend to the outside of the wound battery cell. The first arc-shaped portion is formed by stamping or rolling the first surrounding wall, and the second arc-shaped portion is formed by stamping or rolling the second surrounding wall; The hardness of the first surrounding wall is greater than the hardness of the second surrounding wall.

2. The wound bean-shaped battery according to claim 1, characterized in that: The first arc-shaped portion is annularly arranged on the first surrounding wall, and a plurality of the first arc-shaped portions are parallel along the axis direction of the first surrounding wall; or, A plurality of the first arc-shaped portions are spirally wound on the first surrounding wall along the axis direction of the first surrounding wall; or, The first arc-shaped portion includes a plurality of sub-arc-shaped portions annularly spaced apart from each other along the circumference of the first surrounding wall.

3. The wound bean-shaped battery according to claim 1, characterized in that: All of the first arc-shaped portions are convexly arranged toward the center of the first surrounding wall, and all of the second arc-shaped portions are convexly arranged toward the center of the second surrounding wall; or, All of the first arc-shaped portions are convexly disposed away from the center of the first surrounding wall, and all of the second arc-shaped portions are convexly disposed away from the center of the second surrounding wall; or, The protruding directions of two adjacent first arc-shaped portions on the first surrounding wall are opposite, and the plurality of first arc-shaped portions form a first wave-shaped structure on the first surrounding wall, and the plurality of second arc-shaped portions on the second surrounding wall form a second wave-shaped structure matching the first wave-shaped structure.

4. The wound bean-shaped battery according to claim 1, characterized in that: A constricted portion is formed at one end of the second surrounding wall away from the top plate, and an end of the constricted portion is pressed against an outer wall of the first surrounding wall or an outer wall of the bottom plate; or, One end of the second surrounding wall away from the top plate is pressed against the outer wall of the first surrounding wall; or, A curling structure is disposed at one end of the second surrounding wall away from the top plate, and the curling structure is tightly pressed against the outer wall of the first surrounding wall.

5. The wound bean-shaped battery according to claim 1, characterized in that: The seal includes a sealing body sandwiched between the first surrounding wall and the second surrounding wall, wherein the sealing body has a first extension portion extending toward the center of the sealing body from one end close to the top plate, and a second extension portion extending toward the bottom plate from one end of the first extension portion away from the sealing body, and the second extension portion is tightly attached to the inner wall of the first surrounding wall.

6. The wound bean-shaped battery according to any one of claims 1 to 5, characterized in that: The bottom shell and the cover cap are both made of metal material.

7. The wound bean-shaped battery according to any one of claims 1 to 5, characterized in that: The pole piece includes a current collector and an active material coated on the current collector, and the pole ear is integrally formed with the current collector; or, The current collector is provided with an empty foil area which is not coated with the active material, one end of the pole ear is welded to the empty foil area, and the other end extends to the outside of the wound battery cell.

8. The wound bean-shaped battery according to any one of claims 1 to 5, characterized in that: When at least two pole lugs are provided on the pole piece, one of the pole lugs is located at the center of the length direction of the pole piece, and the remaining pole lugs are spaced apart from the pole lug located at the center of the length direction of the pole piece.

9. The wound bean-shaped battery according to claim 8, characterized in that: At least two and an odd number of the pole ears are arranged on the pole piece, one of the pole ears is located at the center of the length direction of the pole piece, and the remaining pole ears are symmetrically arranged relative to the center of the length direction of the pole piece.

10. The wound bean-shaped battery according to any one of claims 1 to 5, characterized in that: The wound battery cell includes a positive electrode sheet, a negative electrode sheet, and a separator arranged between the positive electrode sheet and the negative electrode sheet, wherein the separator has an isolating portion extending along the axial direction of the wound battery cell to both ends of the negative electrode sheet, and the isolating portion is used to isolate the electrode ears of the wound battery cell from the end face of the wound battery cell.

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