WO2021114329A1

WO2021114329A1 - Winding-type button cell

Info

Publication number: WO2021114329A1
Application number: PCT/CN2019/126223
Authority: WO
Inventors: 冯彪; 葛辉明; 袁中直; 刘金成
Original assignee: 惠州亿纬锂能股份有限公司
Priority date: 2019-12-13
Filing date: 2019-12-18
Publication date: 2021-06-17

Abstract

A winding-type button cell. The winding-type button cell comprises a base housing (1), a cover cap (2) and an auxiliary member (5), wherein a space for accommodating a winding-type cell core (3) is formed between the base housing (1) and the cover cap (2); and one tab (31) of the winding-type cell core (3) is connected to the cover cap (2), and the other tab (31) thereof is connected to the base housing (1). The base housing (1) comprises a base plate (11) and a first surrounding wall (12) annularly arranged on one side surface of the base plate (11, and the cover cap (2) comprises a top plate (21) and a second surrounding wall (22) annularly arranged on one 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) in the axis direction thereof, and the second surrounding wall (22) is provided with a plurality of second arc-shaped portions (23), which match the first arc-shaped portions (13), in the axis direction thereof; and a sealing member (4) is clamped between the first surrounding wall (12) and the second surrounding wall (22). The auxiliary member (5) is of a tubular structure with openings at two ends thereof, and is provided with a first end and a second end, which are arranged opposite each other, wherein the end of the winding-type cell core (3) away from the base plate (11) is inserted into the first end, and the second end is located above the winding-type cell core (3).

Description

Coiled bean battery

This application claims the priority of the following two Chinese patent applications. They are: Item 1: Application date: December 13, 2019, application number: 201911286230.8; Item 2: Application date: December 13, 2019 Date, the application number is: 201922262518.3, and the entire content of the application is incorporated into this application by reference.

Technical field

The present disclosure relates to the field of battery technology, for example, to a wound bean battery.

Background technique

Button battery, also called button battery, refers to a battery whose shape and size are like a small button. The button battery generally includes a bottom shell, a cap, and a battery cell arranged in a containing cavity formed by the two. Because the size of the button battery is very small, it is very difficult to seal. The assembly process of the button battery is as follows: the sealing ring is sleeved on the bottom case, after operations such as placing the battery, the cap is placed on the bottom case for sealing treatment. Although the existing button battery contains a sealing ring, its sealing effect is still general, which easily causes battery leakage and affects the service life of the button battery. In addition, the sealing ring is also prone to breakage during sealing, resulting in sealing failure.

In addition, in order to inject more electrolyte into the battery, battery manufacturers usually use multiple injections, that is, first inject a part of the electrolyte into the battery, vacuum or wait for the electrolyte to be absorbed into the coil. Winding the battery core, and inject another part of the electrolyte after the shell has made a certain space. This liquid injection method has low efficiency, long operation time, and high accuracy requirements for liquid injection equipment.

Summary of the invention

A wound bean battery is provided, comprising a bottom case and a cap, a space for accommodating a wound cell is formed between the bottom case and the cap, and a tab of the wound cell is connected to the battery. The cap is connected, and the other tab is connected with the bottom shell. The bottom shell includes a bottom plate and a first surrounding wall ringed on one side of the bottom plate. The cover cap includes a top plate and a ring ring mounted on the top plate. The second surrounding wall on the side, the second surrounding wall is sleeved outside the first surrounding wall, and a plurality of continuous first arc-shaped portions are provided on the first surrounding wall along the axial direction of the first surrounding wall. A plurality of second arc-shaped parts cooperating with the first arc-shaped part are provided on the second surrounding wall along its axial direction, and a sealing element is sandwiched between the first surrounding wall and the second surrounding wall;

The wound bean-type battery also includes an auxiliary member, the auxiliary member is a cylindrical structure with open ends, which has a first end and a second end disposed oppositely, and the wound battery core is far away from the bottom plate. One end is inserted into the first end, and the second end is located above the wound cell.

In an embodiment, 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 axial 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 axial direction of the first surrounding wall; or,

The first arc-shaped portion includes a plurality of sub-arc-shaped portions arranged at annular intervals along the circumferential direction of the first surrounding wall.

In an embodiment, the first arc-shaped part is formed by stamping or rolling of the first surrounding wall, and the second arc-shaped part is formed by stamping or rolling of the second surrounding wall.

In one embodiment, all the first arc-shaped portions are protruding toward the center of the first surrounding wall, and all the second arc-shaped portions are protruding toward the center of the second surrounding wall. ;or,

All the first arc-shaped parts are protruding toward the center away from the first surrounding wall, and all the second arc-shaped parts are protruding toward the center away from the second surrounding wall; or,

The protruding directions of the 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, so The plurality of second arc-shaped portions on the second surrounding wall form a second wave-shaped structure that matches with the first wave-shaped structure.

In an embodiment, the auxiliary member is wound by adhesive tape, and the first end of the auxiliary member is pasted on the outer peripheral portion of the wound cell;

or,

The material of the auxiliary member is the same as the diaphragm material of the wound cell, and the auxiliary member is wrapped around the outer periphery of the wound cell; or,

The auxiliary part and the wound cell are an integral structure.

In an embodiment, the hardness of the first surrounding wall is greater than the hardness of the second surrounding wall.

In one embodiment, a necked part is formed at an end of the second surrounding wall away from the top plate, and the end of the necked part abuts against the outer wall of the first surrounding wall or the outer wall of the bottom plate; or ,

The end of the second surrounding wall away from the top plate is pressed against the outer wall of the first surrounding wall; or,

A crimping structure is provided at one end of the second surrounding wall away from the top plate, and the crimping structure abuts against the outer wall of the first surrounding wall.

In an embodiment, the sealing element includes a sealing body sandwiched between the first surrounding wall and the second surrounding wall, and one end of the sealing body close to the top plate extends toward the center of the sealing body There is a first extension, and an end of the first extension away from the sealing body extends toward the bottom plate with a second extension, and the second extension is tightly attached to the inner wall of the first surrounding wall.

In an embodiment, both the bottom shell and the cap are made of metal materials.

In one embodiment, the pole piece of the wound cell includes a current collector and an active material coated on the current collector, and the current collector has a radial direction extending to the wound cell The extension part outside the active material is partially overlapped after being bent, the extension part is arranged at an angle with the pole piece, and the extension part is bent to form the tab ear.

In an embodiment, the wound cell includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet, and the separator has a direction along the axis of the wound cell The isolation portions extending to the two ends of the negative electrode sheet are used to isolate the tabs and the end faces of the wound battery core.

The wound bean-type battery provided by the embodiment of the application is provided with corresponding arc-shaped parts on the first and second surrounding walls, and the arc-shaped parts can be arranged to compress the sealing element on the first and second surrounding walls. Between the two enclosing walls, the sealing performance between the bottom shell and the cap is significantly improved, and the arc-shaped part can also protect the seal, prevent the seal from being damaged during the edge sealing of the cap, and prolong the service life of the seal At the same time, it also ensures that the seal between the bottom case and the cap does not fail; by setting an auxiliary part above the winding cell, this auxiliary part can temporarily store the electrolyte. When the injection operation is performed, the electrolyte injection device will remove the electrolyte. Inject into the auxiliary parts, the electrolyte slowly enters the gap of the wound cell, and is absorbed by the wound cell, which can effectively prevent the electrolyte from overflowing. At the same time, the electrolyte is injected and formed at one time. Dadi has improved production efficiency and reduced production costs.

Description of the drawings

FIG. 1 is a schematic cross-sectional view of a wound bean battery provided by an embodiment;

Figure 2 is an exploded schematic diagram of Figure 1;

3 is a schematic cross-sectional view of another wound bean battery provided by an embodiment;

Fig. 4 is an exploded schematic diagram of Fig. 3;

5 is a schematic cross-sectional view of another wound bean battery provided by an embodiment;

Fig. 6 is an exploded schematic diagram of Fig. 5;

FIG. 7 is a schematic cross-sectional view of still another wound bean battery provided by an embodiment;

8 is a schematic cross-sectional view of the wound battery core and auxiliary components of the wound bean battery provided by an embodiment after being assembled;

9 is a schematic diagram of the structure of pole pieces and tabs of a wound bean battery provided by an embodiment;

10 is a schematic diagram of the structure of the pole piece and the tab of another wound bean battery provided by an embodiment;

In the picture:

1. Bottom shell; 11. Bottom plate; 12. First surrounding wall; 13. First arc part;

2. Cap; 21. Top plate; 22. Second surrounding wall; 23. Second arc part; 24. Crimping structure;

3. Wound cell; 31, pole tab; 311, positive pole; 312, negative pole; 32, extension; 321, overlapping position; 33, reinforcement; 34, pole piece; 341, positive pole; 342 , Negative plate; 35, separator; 351, isolation part;

4. Seal; 41, the sealing body; 42, the first extension; 43, the second extension;

5. Auxiliary parts.

Detailed ways

The technical solution of this document will be further described in detail below in conjunction with the accompanying drawings.

1 to 6, the wound bean-type battery of the present disclosure includes a bottom case 1, a cap 2 and an auxiliary member 5. A space for accommodating the wound battery core 3 is formed between the bottom case 1 and the cap 2 One pole 31 of the wound cell 3 is connected to the cap 2, and the other pole 31 is connected to the bottom case 1. The bottom case 1 includes a bottom plate 11 and a first surrounding wall 12 ringed on one side of the bottom plate 11, and the cap 2 It includes a top plate 21 and a second surrounding wall 22 ringed on one side of the top plate 21. The second surrounding wall 22 is sleeved outside the first surrounding wall 12, and a plurality of continuous first surrounding walls 12 are provided along the axial direction of the first surrounding wall. An arc-shaped portion 13, and a plurality of second arc-shaped portions 23 that cooperate with the first arc-shaped portion 13 are provided on the second surrounding wall 22 along its axial direction, and the first surrounding wall 12 and the second surrounding wall 22 are sandwiched between A sealing member 4 is provided. The auxiliary member 5 is a cylindrical structure with two ends open, and has a first end and a second end oppositely arranged. The end of the wound cell 3 away from the bottom plate 11 is inserted into the first end. The two ends are located above the wound cell 3. By providing corresponding arc-shaped parts on the first surrounding wall 12 and the second surrounding wall 22, the arrangement of the arc-shaped parts can press the sealing element 4 between the first surrounding wall 12 and the second surrounding wall 22, and In a limited space (the size of the bean battery is small, for example: the diameter is 10mm-13mm, the height is 3mm-6mm), the convex arc part can be used to form a longer sealing reinforced area, which effectively raises the bottom. The tightness between the shell 1 and the cap 2, and the contact position between the arc-shaped part and the sealing element 4 is a circular arc surface, which can effectively prevent the sealing element 4 from contacting sharp parts, thereby preventing the sealing element 4 from sealing in the cap 2. When the edge is damaged, the service life of the sealing element 4 is prolonged, and the seal between the bottom case 1 and the cap 2 is not invalidated; by setting the auxiliary part 5 above the winding cell 3, the auxiliary part 5 can be temporarily The electrolyte is stored. During the injection operation, the injection equipment injects the electrolyte into the auxiliary part 5, and the electrolyte slowly enters the gap of the wound cell 3 and is wound by the cell 3 Absorption, which can effectively prevent the electrolyte from overflowing, and at the same time, can inject a sufficient amount of electrolyte at one time, which greatly improves the production efficiency and reduces the production cost.

In an embodiment, as shown in FIGS. 1 and 2, 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 circular arc-shaped part can not only ensure better sealing effect, effectively prevent liquid leakage, but also reduce manufacturing difficulty and improve production efficiency. In addition, the arc-shaped part of this structure is along the first wall 12 or the second wall There is no interval for 22 weeks to further enhance the sealing effect.

It is not limited to setting the arc-shaped part as an integral ring structure, and each arc-shaped part may also be provided as an annularly spaced structure. The first arc-shaped part 13 includes a plurality of sub-shaped parts arranged at an annular interval along the circumferential direction of the first surrounding wall 12. The arc-shaped portion, the positions of the sub-arc-shaped portions of the two adjacent first arc-shaped portions 13 are in one-to-one correspondence. Correspondingly, the second arc-shaped portion 23 also includes a plurality of sub-arc-shaped portions arranged circumferentially along the second surrounding wall 22. For the arc-shaped part, the positions of the sub-arc-shaped parts of the two adjacent second arc-shaped parts 23 are in one-to-one correspondence, so that the positions of the first arc-shaped part 13 and the second arc-shaped part 23 can correspond to each other to achieve a fit.

The sub-arc parts of each first arc-shaped part 13 are symmetrically arranged along the central axis of the wound cell 3, and the positions of the sub-arc parts of two adjacent first arc-shaped parts 13 are in one-to-one correspondence.

One-to-one correspondence means that when viewed from above, the sub-arc portion in the uppermost first arc-shaped portion 13 completely shields the remaining sub-arc portions of the first arc-shaped portion 13. In addition, a plurality of first arc-shaped portions 13 may be spirally wound on the first surrounding wall 12 along the axial direction of the first surrounding wall 12. Correspondingly, the plurality of second arc-shaped portions 23 along the second surrounding wall 22 The axis direction is spirally wound on the second surrounding wall 22. The spirally wound structure allows the cap 2 to be screwed on the bottom shell 1, which not only makes the sealing stronger, but also can be installed in a spiral manner to reduce the wear on the sealing element 4, and effectively extend the service life of the sealing element 4.

In one embodiment, the first arc-shaped portion 13 is formed by stamping or rolling of the first surrounding wall 12, and the second arc-shaped portion 23 is formed by stamping or rolling of the second surrounding wall 22. Stamping or roll forming the arc-shaped part can not only reduce the manufacturing difficulty, but also form a corresponding groove on the protruding back side of the arc-shaped part, and use this groove to accommodate the arc-shaped part that is attached to it to achieve a tight fit.

In one embodiment, as shown in FIGS. 1 and 2, all the first arc-shaped portions 13 are protruding toward the center of the first surrounding wall 12, and all the second arc-shaped portions 23 are facing toward the center of the second surrounding wall 22. The center protrudes.

In one embodiment, as shown in FIGS. 3 and 4, all the first arc-shaped parts 13 are arranged to protrude away from the center of the first surrounding wall 12, and all the second arc-shaped parts 23 are facing away from the second surrounding wall. The center of 22 protrudes.

In an embodiment, as shown in FIGS. 5 and 6, the projection directions of the two adjacent first arc-shaped portions 13 on the first surrounding wall 12 are opposite, and a plurality of first arc-shaped portions 13 are formed on the first surrounding wall 12 A first wave-shaped structure is formed on the upper side, and a plurality of second arc-shaped portions 23 on the second surrounding wall 22 form a second wave-shaped structure that matches the first wave-shaped structure. The wave-shaped structure can make the first surrounding wall 12 and the second surrounding wall 22 fit more closely, and the sealing performance is better.

In order to ensure that the wound bean-type battery is not deformed 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, and the first surrounding wall 12 has a higher hardness and can be used as a support. The base body, whether in the steps of assembling the seal 4, the cap 2 or sealing the cap 2, will not deform the first surrounding wall 12 (ie the bottom shell 1) or the deformation of the first surrounding wall 12 is much smaller than that of the first surrounding wall 12 The deformation of the two surrounding walls 22 ensures that the appearance and sealing of the wound bean battery will not fail.

In an embodiment, as shown in FIGS. 1 and 2, the first end is connected to the end of the winding cell 3 away from the bottom plate 11. This design can make the auxiliary part 5 occupy as little as possible the bottom shell 1 or even the entire winding type bean. The internal space of the battery case. Preferably, the first end of the auxiliary member 5 is connected to the outer periphery of the wound cell 3, which can expand the space for storing the electrolyte of the auxiliary member 5, and also facilitate the connection of the auxiliary member 5 and the wound cell 3 at the same time.

The auxiliary member 5 can be 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 inner cavity of the auxiliary member 5 have the same diameter everywhere. When liquid is injected, the pressure of the electrolyte in the inner cavity directly acts At the end of the wound cell 3, the pressure of the electrolyte in the cavity on the wound cell 3 is increased, which is more conducive to the absorption of the electrolyte by the wound cell 3 and improves the wound bean type. Battery production efficiency. Of course, the auxiliary member 5 can also be configured 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 electrolyte injection and reduce the accuracy requirements of the injection equipment.

In order to provide a reference for the amount of electrolyte injected in the auxiliary part 5, the inner cavity of the auxiliary part 5 is provided with a liquid level height line. The specific height of the electrolyte that needs to be temporarily stored in the inner cavity can be calculated before the electrolyte is injected, and then In the actual injection process, only the electrolyte needs to be controlled at this height to achieve precise injection, which helps to accurately control the amount of electrolyte injection.

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 peripheral portion of the wound cell 3. Since the adhesive tape is thin and has a certain shaping effect, the adhesive tape is wound into the auxiliary part 5. After the liquid injection is completed, the auxiliary part 5 does not need to be removed from the wound cell 3, and the adhesive tape can be directly packaged In the shell composed of the bottom shell 1 and the cap 2, almost no internal space of the shell is occupied, which facilitates the improvement of the battery energy density and the reduction of the packaging difficulty, so that the production efficiency of the wound bean battery is high. Specifically, the adhesive tape may be made of polypropylene (PP) or polyethylene terephthalate (PET) or polyimide (PI).

When the adhesive tape is used as an auxiliary part, it can also act as a finishing glue, which can further reduce the cost.

In an embodiment, the auxiliary member 5 is not limited to being wound by adhesive tape, and may also be wound by using other materials that do not affect the battery performance, for example, by winding and forming the same material as the separator 35.

Or the auxiliary member 5 is directly integrated with the wound battery 3 as an integral structure, and the size of the diaphragm 35 adjacent to the outer ring can be made larger, so that the wound diaphragm 35 forms a circle outside the outer circumference of the wound battery 3 A structure protruding from the end surface of the end of the wound cell 3 away from the bottom plate 11, and this structure at least surrounds the outer circumference of the wound cell 3 to form an auxiliary member 5. This design can save additional manufacturing and installation of the auxiliary component 5, so that the auxiliary component 5 is formed after the wound battery core 3 is wound.

In an embodiment, the tabs 31 of the wound cell 3 are all arranged on the outer ring of the wound cell 3.

In other embodiments, the tab 31 can also be directly drawn from the center position of the wound cell 3 or close to the center position. The center position of the wound cell 3 is the position at the start end of the winding during the winding process. The winding of the wound cell 3 is taken as the winding center, that is, a positive lug 311 is arranged on the positive electrode sheet 341 close to the winding center of the wound cell 3 or the center position, and the negative electrode sheet 342 is close to the winding center. The winding center or central position of the wound cell 3 is provided with a negative lug 312. After the positive electrode sheet 341, the negative electrode sheet 342 and the separator 35 are stacked, the winding starts from the end where the positive electrode lug 311 and the negative electrode lug 312 are arranged to form this Winding core 3. The positive lug 311 and the negative lug 312 are respectively drawn from the two ends of the winding cell 3 in the axial direction. Specifically, the positive lug 311 is drawn from the upper end of the winding cell 3 and connected to the cap 2, and the negative lug 312 is drawn by the winding cell 3. The lower end of the electric core 3 is led out and connected to the bottom case 1.

Of course, the positive lug 311 and the negative lug 312 are not limited to being drawn from the two ends of the winding cell 3 in the axial direction, and the positive lug 311 and the negative lug 312 can also be drawn from the same end in the axial direction of the winding cell 3. .

In addition, the non-end position of the pole piece 34 of the wound cell 3 is provided with an empty foil area. Both ends of the core 3 in the axial direction are drawn. When a tab 31 is provided on the pole piece 34, the tab 31 is preferably set at the center of the length direction of the pole piece 34. When a plurality of tabs 31 are provided on the pole piece 34, preferably one of the tabs 31 is set at At the center position of the pole piece 34 in the longitudinal direction, the remaining tab 31 is spaced apart from the tab 31 at the center position.

The wound cell 3 can be cylindrical, square cylindrical, elliptical, or the like.

The tabs 31 are not limited to the two ends of the wound cell 3, and may also be at the same end of the wound cell 3.

In an embodiment, a necking portion is formed at an end of the second surrounding wall 22 away from the top plate 21, and the end of the necking portion abuts against the outer wall of the first surrounding wall 12. The arrangement of the necking part can effectively prevent the cover 2 from being separated from the bottom shell 1 and can further improve the sealing performance between the bottom shell 1 and the cover 2.

Of course, the end of the necking part is not limited to abut on the outer wall of the first surrounding wall 12, and the second surrounding wall 22 of the cap 2 can also be set to be long enough so that the cap 2 can extend to the bottom plate after being assembled on the bottom shell 1. 11 is away from a side surface of the first surrounding wall 12, and then the necking part of the second surrounding wall 22 is necked, and the necking part abuts against the outer wall of the bottom plate 11 at this time.

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 a necking part, or as shown in FIG. 7, the end of the second surrounding wall 22 away from the top plate 21 The crimping process is performed to form a crimping structure 24, and the crimping structure 24 can also improve the tightness between the bottom shell 1 and the cap 2.

In one embodiment, as shown in FIGS. 1 to 6, the sealing member 4 includes a sealing body 41 sandwiched between the first surrounding wall 12 and the second surrounding wall 22, and one end of the sealing body 41 close to the top plate 21 faces the sealing body 41 A first extension portion 42 extends from the center of the first extension portion 42. A second extension portion 43 extends toward the bottom plate 11 at one end of the first extension portion 42 away from the sealing body 41. The second extension portion 43 is 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 two surrounding walls are provided with the corresponding first arc-shaped portion 13 and the second arc-shaped portion 23, the sealing body 41 is extruded to form a plurality of concave-convex structures. Due to the concave-convex structure 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 and can effectively prevent leakage. The occurrence of liquid phenomenon.

Of course, the sealing member 4 can also be provided with a third arc part matching the first arc part 13 and the second arc part 23 in advance. By providing the third arc part, the sealing member 4 can be connected to the first arc part. The surrounding wall 12 and the second surrounding wall 22 are more closely attached, and the sealing performance is better.

In this embodiment, the third arc-shaped portion is provided on the sealing body 41.

In addition, the first extension 42 and the second extension 43 can cooperate with the sealing body 41 to form a positioning structure for the sealing element 4. During installation, the upper end of the first surrounding wall 12 is clamped on the second extension 43 and the sealing body. 41, and the first extension 42 abuts against the end surface of the upper end of the first surrounding wall 12 to realize the position positioning of the sealing member 4.

The length of the second extension part 43 in the vertical direction is smaller than the width of the single first arc-shaped part 13 or the second arc-shaped part 23 in the vertical direction, so that the size of the second extension part 43 in the first surrounding wall 12 is relatively small. Short, this can reduce material consumption, thereby reducing manufacturing costs, while also ensuring the basic positioning effect.

In one embodiment, both the bottom shell 1 and the cap 2 are made of metal materials. The bottom shell 1 and the cap 2 made of metal materials have high hardness, which makes the whole shell of the wound bean battery a hard shell. The hard shell structure can ensure that the appearance of the whole wound bean battery remains unchanged and is effective. Prevent deformation of the casing caused by gas in the battery.

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

In this embodiment, the metal material is stainless steel.

In an embodiment, as shown in FIGS. 1, 9 and 10, the pole piece 34 of the wound cell 3 is divided into a positive electrode piece 341 and a negative electrode piece 342. The shape of the positive electrode piece 341 and the negative electrode piece 342 are similar, and each Each pole piece 34 includes a current collector and an active material coated on the current collector. The current collector has an extension 32 that extends to the outside of the active material in the radial direction of the wound cell 3, and the extension 32 is folded and partially stacked. Together, the extension portion 32 and the pole piece 34 are arranged at an included angle, and the extension portion 32 forms a pole lug 31. By extending the extension portion 32 of the current collector of the pole piece 34 to the outside of the active material, the tab 31 is directly formed after bending, eliminating the need for welding the tab 31, improving production efficiency, and reducing the winding cell 3 At the same time, the integrally formed tab 31 and tab 34 have higher strength and are not easy to detach.

The overlapping position 321 of the extension portion 32 may be provided with a reinforcing member 33. By arranging an additional reinforcing member 33 at the overlapping position 321 of the extension portion 32, the reinforcing member 33 can strengthen the strength of the folded overlapping position 321, effectively preventing the extension portion 32 from being broken after bending, and protecting the integrity of the tab 31, At the same time, the overall strength of the tab 31 is strengthened.

The bending angle of the extension portion 32 can be flexibly adjusted according to the requirements of the winding cell 3 during packaging. Specifically, the extension portion 32 is bent with the position connected to the end of the pole piece 34 as the fulcrum, and the first clip is bent. Angle α, where the first included angle α is 90°, this angle can facilitate the extension 32 to be drawn from the two ends of the wound cell 3, shorten the length of the tab 31, and reduce the manufacturing cost. Of course, the bending angle of the extension portion 32 is not limited to 90°, and the first included angle α can also be set to 30°, 45°, 100°, 120°, etc. as required.

In one embodiment, as shown in FIG. 9, the reinforcing member 33 is wrapped with an adhesive tape outside the overlapping position 321 of the extension portion 32. Setting the reinforcing member 33 as an adhesive tape can buffer the overlapping position 321 of the extension portion 32 after bending, which can reduce the stress of the extension portion 32 at the bending position to a certain extent, and effectively reduce the overlapping of the extension portion 32. The break of the joint position 321 causes the tab 31 and the tab 34 to separate. On the other hand, the structure of the overlapping position 321 of the extension part 32 is protected and shaped by tape to prevent the tab 31 from passing a long time. After the use of, the extension portion 32 deforms at the folded position 321 after bending, which affects the normal use of the wound cell 3. In order to further enhance the protective effect of the adhesive tape on the extension portion 32, multiple layers of adhesive tape may be wound at the overlapping position 321.

In one embodiment, as shown in FIG. 10, the reinforcing member 33 is a double-sided adhesive tape, and the extension portion 32 is provided with a first overlapping surface and a second overlapping surface that are attached to each other at the overlapping position 321. The double-sided adhesive tape It is arranged between the first overlapping surface and the second overlapping surface. The arrangement of the double-sided tape can effectively prevent the separation of the first overlapping surface and the second overlapping surface, so as to prevent the tab 31 from occupying the space between the bottom shell 1 and the cap 2.

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

In one embodiment, as shown in FIG. 8, a separator 35 is provided between the positive electrode sheet 341 and the negative electrode sheet 342 of the wound cell 3, and the separator 35 has a shape extending along the axis of the wound cell 3 to the negative electrode sheet 342. The isolation portions 351 at the two ends of the, the isolation portions 351 are used to isolate the tab 31 of the wound cell 3 and the end surface of the wound cell 3. The arrangement of the isolation portion 351 can effectively prevent the tab 31 from making electrical contact with the two ends of the wound cell 3 in the vertical direction, and there is no need to additionally provide insulating spacers on the end surface of the wound cell 3, which reduces the winding The difficulty and cost of the preparation of the 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.

In this embodiment, the length of the isolation portion 351 extending beyond the end surface of the wound cell 3 is not less than 0.75 mm. This design can ensure that the end surface of the wound 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 isolation portion 351 to isolate the tab 31 and ensure the insulation effect.

In addition, generally, since the current collector of the positive electrode tab 341 is aluminum foil and the current collector of the negative electrode tab 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. As for the aluminum foil and copper foil, both are softer than the conventional aluminum sheet or nickel sheet of the material of the tab, so that the spacer 351 is not easily pierced by the tab 31 when it is attached to the end surface of the wound cell 3.

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

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

The aforementioned wound bean battery is a rechargeable bean battery.

Claims

A wound bean-type battery includes a bottom shell and a cap, a space for accommodating a wound cell is formed between the bottom shell and the cap, and a tab of the wound cell and the cap Connected, the other tab is connected to the bottom shell, characterized in that the bottom shell includes a bottom plate and a first surrounding wall ringed on one side of the bottom plate, and the cap includes a top plate and a ring mounted on the bottom A second surrounding wall on one side of the top plate, the second surrounding wall is sleeved outside the first surrounding wall, and a plurality of continuous first arc-shaped parts are provided on the first surrounding wall along the axial direction thereof, so The second surrounding wall is provided with a plurality of second arc-shaped parts that cooperate with the first arc-shaped part along the axial direction thereof, and a sealing element is sandwiched between the first surrounding wall and the second surrounding wall ；

It also includes an auxiliary member, which is a cylindrical structure with open ends, and has a first end and a second end that are oppositely disposed. The end of the wound battery core away from the bottom plate is inserted into the first In the end, the second end is located above the wound cell.
The wound bean battery according to claim 1, wherein the first arc-shaped part is annularly arranged on the first surrounding wall, and a plurality of the first arc-shaped parts are arranged along the first wall. The axis of the wall is parallel; or,

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

The first arc-shaped portion includes a plurality of sub-arc-shaped portions arranged at annular intervals along the circumferential direction of the first surrounding wall.
The wound bean battery according to claim 1, wherein the first arc-shaped portion is formed by stamping or rolling of the first surrounding wall, and the second arc-shaped portion is formed by the second The surrounding wall is formed by pressing or rolling.
The wound bean-type battery according to claim 3, wherein all the first arc-shaped portions are protruding toward the center of the first surrounding wall, and all the second arc-shaped portions Are protruding toward the center of the second surrounding wall; or,

All the first arc-shaped parts are protruding toward the center away from the first surrounding wall, and all the second arc-shaped parts are protruding toward the center away from the second surrounding wall; or,

The protruding directions of the 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, so The plurality of second arc-shaped portions on the second surrounding wall form a second wave-shaped structure that matches with the first wave-shaped structure.
The wound bean battery according to claim 1, wherein the auxiliary member is wound by tape, and the first end of the auxiliary member is pasted on the winding battery core Peripheral part; or,

The material of the auxiliary member is the same as the diaphragm material of the wound cell, and the auxiliary member is wrapped around the outer periphery of the wound cell; or,

The auxiliary part and the wound cell are an integral structure.
The wound bean battery according to claim 1, wherein the hardness of the first surrounding wall is greater than the hardness of the second surrounding wall.
The wound bean-type battery according to claim 1, wherein the end of the second surrounding wall away from the top plate is formed with a necked part, and the end of the necked part is pressed against the first The outer wall of a surrounding wall or the outer wall of the bottom plate; or,

The end of the second surrounding wall away from the top plate is pressed against the outer wall of the first surrounding wall; or,

A crimping structure is provided at one end of the second surrounding wall away from the top plate, and the crimping structure abuts against the outer wall of the first surrounding wall.
The wound bean battery according to claim 1, wherein the sealing member comprises a sealing body sandwiched between the first surrounding wall and the second surrounding wall, and the sealing body is close to One end of the top plate extends toward the center of the sealing body with a first extension, and one end of the first extension away from the sealing body extends toward the bottom plate with a second extension, and the second extension is attached to Tightly on the inner wall of the first surrounding wall.
The wound bean battery according to any one of claims 1 to 8, wherein the bottom shell and the cap are both made of metal materials.
The wound bean battery according to any one of claims 1 to 8, wherein the pole piece of the wound battery cell comprises a current collector and an active material coated on the current collector, so The current collector has an extension part extending outside the active material along the radial direction of the wound cell, the extension part is folded and partially overlapped, and the extension part forms an angle with the pole piece If provided, the extension portion is bent to form the tab.
The wound bean battery according to any one of claims 1 to 8, wherein the wound battery cell comprises a positive electrode sheet, a negative electrode sheet, and the battery is arranged between the positive electrode sheet and the negative electrode sheet. The separator has a separator extending along the axis of the wound cell to both ends of the negative electrode sheet, and the separator is used to separate the tabs from the wound cell End face.