Wound bean battery

Abstract

The present invention discloses a wound bean-shaped battery, comprising a bottom shell, a cap and an auxiliary part, a space for accommodating a wound battery cell is formed between the bottom shell and the cap, one pole ear of the wound battery 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 parts are arranged on the first surrounding wall along its axial direction, a plurality of second arc-shaped parts matching the first arc-shaped parts are arranged on the second surrounding wall along its axial direction, a sealing part is sandwiched between the first surrounding wall and the second surrounding wall, the auxiliary part is a cylindrical structure with two ends open, and has a first end and a second end arranged oppositely, an end of the wound battery cell away from the bottom plate is inserted into the first end, and the second end is located above the wound battery cell. The wound bean-shaped battery of the present invention has a simple structure, good sealing effect and high liquid injection efficiency.

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, in order to inject more electrolyte into the battery, battery manufacturers usually adopt multiple injection methods, that is, inject a part of the electrolyte into the battery first, evacuate or wait for the electrolyte to be absorbed into the wound battery cell, and inject another part of the electrolyte after a certain space is vacated in the shell. This injection method is inefficient, takes a long time to operate, and requires high precision of the injection equipment. 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-shaped battery with high liquid injection efficiency.

[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] It also includes an auxiliary part, which is a cylindrical structure with two ends open, and has a first end and a second end arranged opposite to each other. The end of the wound battery core away from the bottom plate is inserted into the first end, and the second end is located above the wound battery core.

[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 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.

[0016] As a preferred solution of the wound bean-type battery, the auxiliary member is wound by adhesive tape, and the first end of the auxiliary member is attached to the outer periphery of the wound battery cell;

[0017] or,

[0018] The material of the auxiliary member is consistent with the material of the separator of the wound battery core, and the auxiliary member is wrapped around the outer periphery of the wound battery core; or,

[0019] The auxiliary component and the wound battery core are an integrated structure.

[0020] 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.

[0021] As a preferred solution of the wound bean-type battery, a necking portion is formed at one end of the second surrounding wall away from the top plate, and an end of the necking portion is pressed against an outer wall of the first surrounding wall or an outer wall of the bottom plate; or,

[0022] One end of the second surrounding wall away from the top plate is pressed against the outer wall of the first surrounding wall; or,

[0023] 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.

[0024] 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.

[0025] As a preferred solution of the wound bean-shaped battery, the bottom shell and the cover cap are both made of metal material.

[0026] As a preferred solution of a wound bean-type battery, the pole piece of the wound battery cell includes a current collector and an active material coated on the current collector, the current collector has an extension portion extending outside the active material along the radial direction of the wound battery cell, the extension portion is partially overlapped after being bent, the extension portion is arranged at an angle with the pole piece, and the extension portion is bent to form the pole ear.

[0027] 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 tab from the end face of the wound battery cell.

[0028] The beneficial effects of the embodiments of the present invention are as follows: by providing corresponding arc-shaped portions on the first surrounding wall and the second surrounding wall, the setting of the arc-shaped portion 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 cover cap, and the setting of the arc-shaped portion can also protect the seal, prevent the seal from being damaged when the cover cap is sealed, thereby extending the service life of the seal, and also ensuring that the seal between the bottom shell and the cover cap does not fail; by providing an auxiliary part above the wound battery cell, the auxiliary part can temporarily store electrolyte, and during the injection operation, the injection equipment injects the electrolyte into the interior of the auxiliary part, and the electrolyte then slowly enters the gap of the wound battery cell and is absorbed by the wound battery cell, which can effectively prevent the electrolyte from overflowing, and at the same time, the electrolyte is injected and formed in one time, which greatly improves the production efficiency and reduces the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention is further described in detail below based on the accompanying drawings and embodiments.

[0030] Figure 1 FIG. 4 is a cross-sectional schematic diagram of a wound bean-shaped battery according to an embodiment of the present invention.

[0031] Figure 2 for Figure 1 Schematic diagram of the decomposition.

[0032] Figure 3 FIG. 4 is a cross-sectional schematic diagram of a wound bean-shaped battery according to another embodiment of the present invention.

[0033] Figure 4 for Figure 3 Schematic diagram of the decomposition.

[0034] Figure 5 FIG. 4 is a cross-sectional schematic diagram of a wound bean-shaped battery according to another embodiment of the present invention.

[0035] Figure 6 for Figure 5 Schematic diagram of the decomposition.

[0036] Figure 7 FIG. 4 is a cross-sectional schematic diagram of a wound bean-shaped battery according to another embodiment of the present invention.

[0037] Figure 8 It is a cross-sectional schematic diagram of an assembled wound battery cell and auxiliary components according to an embodiment of the present invention.

[0038] Fig. 9 Schematic diagram of the structure of a pole piece and a pole ear according to an embodiment of the present invention.

[0039] Fig.10 It is a schematic structural diagram of a pole piece and a pole ear according to another embodiment of the present invention.

[0040] In the figure:

[0041] 1. bottom shell; 11. bottom plate; 12. first surrounding wall; 13. first arc-shaped portion;

[0042] 2. Cover cap; 21. Top plate; 22. Second surrounding wall; 23. Second arc-shaped portion; 24. Curling structure;

[0043] 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;

[0044] 4. sealing member; 41. sealing body; 42. first extension portion; 43. second extension portion;

[0045] 5. Auxiliary parts. 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 6As shown, the wound bean-shaped battery disclosed in the present invention comprises a bottom shell 1, a cap 2 and an auxiliary member 5, wherein a space for accommodating a wound battery cell 3 is formed between the bottom shell 1 and the cap 2, wherein 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, wherein the bottom shell 1 comprises a bottom plate 11 and a first surrounding wall 12 arranged around a side surface of the bottom plate 11, wherein the cap 2 comprises a top plate 21 and a second surrounding wall 22 arranged around a side surface of the top plate 21, wherein the second surrounding wall 22 is sleeved outside the first surrounding wall 12 The first surrounding wall 12 is provided with a plurality of continuous first arc-shaped portions 13 along its axial direction, the second surrounding wall 22 is provided with a plurality of second arc-shaped portions 23 cooperating with the first arc-shaped portions 13 along its axial direction, a sealing member 4 is sandwiched between the first surrounding wall 12 and the second surrounding wall 22, the auxiliary member 5 is a cylindrical structure with openings at both ends, and has a first end and a second end arranged oppositely, the end of the wound battery cell 3 away from the bottom plate 11 is inserted into the first end, and the second end is located above the wound battery cell 3. By providing corresponding arc-shaped portions on the first surrounding wall 12 and the second surrounding wall 22, the setting of the arc-shaped 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 by using the protruding arc-shaped portions 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), thereby effectively improving the sealing between the bottom shell 1 and the cap 2, and the contact position between the arc-shaped portion and the seal 4 is an arc surface, which can effectively prevent the seal 4 from contacting with sharp parts, thereby The seal 4 is prevented from being damaged when the cap 2 is sealed, and the service life of the seal 4 is extended, while also ensuring that the seal between the bottom shell 1 and the cap 2 does not fail; by arranging an auxiliary component 5 above the wound battery cell 3, the auxiliary component 5 can temporarily store the electrolyte, and when performing the injection operation, the injection equipment injects the electrolyte into the interior of the auxiliary component 5, and the electrolyte then slowly enters the gap of the wound battery cell 3 and is absorbed by the wound battery cell 3, which can effectively prevent the electrolyte from overflowing, and at the same time, a sufficient amount of electrolyte can be injected at one time, which greatly improves the production efficiency and reduces the production cost.

[0050] like Figure 1 and Figure 2 As 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 .

[0056] 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 .

[0057] In another specific embodiment of the present invention, Figure 5 and6 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.

[0058] 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.

[0059] In one embodiment, if Figure 1 and 2 As shown, the first end is connected to the end of the wound battery cell 3 away from the bottom plate 11. This design can minimize the space occupied by the auxiliary component 5 in the bottom shell 1 or even the entire wound bean-shaped battery shell. Preferably, the first end of the auxiliary component 5 is connected to the outer periphery of the wound battery cell 3, which can expand the space for the auxiliary component 5 to store electrolyte and also facilitate the connection between the auxiliary component 5 and the wound battery cell 3.

[0060] Preferably, the auxiliary component 5 is a cylindrical structure, that is, the size of the first end is equal to the size of the second end. This design can make the diameter of the inner cavity of the auxiliary component 5 consistent at all places. When injecting liquid, the pressure of the electrolyte in the inner cavity directly acts on the end of the wound battery cell 3, increasing the pressure of the electrolyte in the inner cavity on the wound battery cell 3, which is more conducive to the absorption of the electrolyte by the wound battery cell 3 and improves the production efficiency of the wound bean-type battery. Of course, in other embodiments, the auxiliary component 5 can also be set as a horn structure, and the size of the first end is smaller than the size of the second end. This design can facilitate the injection of electrolyte and reduce the accuracy requirements for the injection equipment.

[0061] In order to provide a reference for the amount of electrolyte injected into the auxiliary component 5, a liquid level height line is provided in the inner cavity of the auxiliary component 5. Before injecting the electrolyte, the specific height of the electrolyte that needs to be temporarily stored in the inner cavity can be calculated first. Then, during the actual injection process, it is only necessary to control the electrolyte at this height to achieve precise injection, which helps to accurately control the amount of electrolyte injected.

[0062] In this embodiment, the auxiliary member 5 is wound by adhesive tape, and the first end of the auxiliary member 5 is pasted on the outer periphery of the wound battery cell 3. Since the adhesive tape is thin and has a certain shaping effect, after the adhesive tape is wound into the auxiliary member 5, it is not necessary to remove the auxiliary member 5 from the wound battery cell 3 after the injection is completed. The adhesive tape can be directly packaged in the shell composed of the bottom shell 1 and the cap 2, and almost no internal space of the shell is occupied, which is convenient for improving the battery energy density, reducing the difficulty of packaging, and making the production efficiency of the wound bean-type battery high. Specifically, the adhesive tape can be made of polypropylene (PP) or polyethylene terephthalate (PET) or polyimide (PI).

[0063] When adhesive tape is used as an auxiliary component, it can also serve as finishing glue, which can further reduce costs.

[0064] In other embodiments, the auxiliary component 5 is not limited to being formed by winding with adhesive tape, but may also be formed by winding with other materials that do not affect the battery performance, such as winding with the same material as the diaphragm 35 .

[0065] Alternatively, the auxiliary component 5 is directly integrated with the wound battery cell 3 as an integral structure, and the size of the diaphragm 35 adjacent to the outer circle can be enlarged, so that the wound diaphragm 35 forms a circle of structure protruding from the end surface of the wound battery cell 3 away from the bottom plate 11 on the outer circumference of the wound battery cell 3, and this structure at least surrounds the outer circumference of the wound battery cell 3 to form the auxiliary component 5. This design can save the additional manufacturing and installation of the auxiliary component 5, so that the auxiliary component 5 is formed after the wound battery cell 3 is wound.

[0066] In one embodiment, the tabs 31 of the wound battery cell 3 are all arranged on the outer ring of the wound battery cell 3 .

[0067] In other embodiments, the pole ear 31 can also be directly led out from the center position or near the center position of the wound battery cell 3. The center position of the wound battery cell 3 is the position at the starting end of the winding process, and the winding of the wound battery cell 3 takes this as the winding center, that is, the positive pole ear 311 is provided on the positive electrode sheet 341 at a position close to the winding center or the center position of the wound battery cell 3, and the negative pole ear 312 is provided on the negative electrode sheet 342 at a position close to the winding center or the center position of the wound battery cell 3. After the positive electrode sheet 341, the negative electrode sheet 342 and the separator 35 are stacked, winding is started from the end where the positive pole ear 311 and the negative pole ear 312 are provided to form this wound battery cell 3. The positive electrode ear 311 and the negative electrode ear 312 are respectively led out from the two ends of the axial direction of the wound battery cell 3. Specifically, the positive electrode ear 311 is led out from the upper end of the wound battery cell 3 and connected to the cap 2, and the negative electrode ear 312 is led out from the lower end of the wound battery cell 3 and connected to the bottom shell 1.

[0068] Of course, the positive electrode tab 311 and the negative electrode tab 312 are not limited to being led out from both ends of the wound battery cell 3 in the axial direction, and the positive electrode tab 311 and the negative electrode tab 312 may also be led out from the same end of the wound battery cell 3 in the axial direction.

[0069] In addition, an empty foil area is provided at a non-end position of the pole piece 34 of the wound battery cell 3, and a pole ear 31 is spot-welded to the empty foil area or extends from the pole ear 31. After winding, the pole ear 31 is led out from both ends of the axial direction of the wound battery cell 3. When one pole ear 31 is provided on the pole piece 34, the pole ear 31 is preferably provided at the center position of the length direction of the pole piece 34. When multiple pole ears 31 are provided on the pole piece 34, one of the pole ears 31 is preferably provided at the center position of the length direction of the pole piece 34, and the remaining pole ears 31 are provided at intervals from the pole ears 31 at the center position.

[0070] The wound battery core 3 may be in a cylindrical, square, or elliptical shape.

[0071] 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 .

[0072] 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.

[0073] 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.

[0074] 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 .

[0075] 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.

[0076] 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.

[0077] In this embodiment, the third arc portion is disposed on the sealing body 41 .

[0078] 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.

[0079] 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.

[0080] 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.

[0081] The metal material here can be a single metal material or an alloy material.

[0082] In this embodiment, the metal material is stainless steel.

[0083] In one embodiment, if Figure 1 , Fig. 9 and Fig.10 As shown, the pole piece 34 of the wound battery cell 3 is divided into a positive pole piece 341 and a negative pole piece 342. The positive pole piece 341 and the negative pole piece 342 are similar in shape. Each pole piece 34 includes a current collector and an active material coated on the current collector. 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 forms 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 integrally formed pole ear 31 and pole piece 34 have higher strength and are not easy to separate.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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 .

[0089] 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.

[0090] 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.

[0091] 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. Aluminum foil and copper foil are both softer than the aluminum sheet or 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.

[0092] 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.

[0093] The diameter-to-height ratio of the wound bean-shaped battery is ≥1; preferably >1.

[0094] The above-mentioned wound bean-shaped battery is a rechargeable bean-shaped battery.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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; It also includes an auxiliary part, which is a cylindrical structure with two ends open, and has a first end and a second end arranged opposite to each other. The end of the wound battery core away from the bottom plate is inserted into the first end, and the second end is located above the wound battery core.

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: 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.

4. The wound bean-shaped battery according to claim 3, 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.

5. The wound bean-shaped battery according to claim 1, characterized in that: The auxiliary member is formed by winding adhesive tape, and the first end of the auxiliary member is adhered to the outer periphery of the wound battery core; or, The material of the auxiliary member is consistent with the material of the separator of the wound battery core, and the auxiliary member is wrapped around the outer periphery of the wound battery core; or, The auxiliary component and the wound battery core are an integrated structure.

6. The wound bean-shaped battery according to claim 1, characterized in that: The hardness of the first surrounding wall is greater than the hardness of the second surrounding wall.

7. 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.

8. 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.

9. The wound bean-shaped battery according to any one of claims 1 to 8, characterized in that: The bottom shell and the cover cap are both made of metal material.

10. The wound bean-shaped battery according to any one of claims 1 to 8, characterized in that: The pole piece of the wound battery cell includes a current collector and an active material coated on the current collector, the current collector has an extension portion extending along the radial direction of the wound battery cell to the outside of the active material, the extension portion is partially overlapped after being bent, the extension portion is arranged at an angle with the pole piece, and the extension portion is bent to form the pole ear.

11. The wound bean-shaped battery according to any one of claims 1 to 8, 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 tab from the end face of the wound battery cell.

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