CYLINDRICAL BATTERY

The disclosure relates to the technical field of batteries and provides a cylindrical battery including a winding cell. The winding cell includes a winding cell body and a first tab extending from one side of the winding cell body. The winding cell body is wound to form a central hole. In a radial direction of the central hole, the first tab includes a plurality of single tabs, and the plurality of single tabs form a first region. Herein, heights of the plurality of single tabs in the first region gradually increase. A difference value between a maximum height difference value and a minimum height difference value between adjacent single tabs in the radial direction of the central hole is less than or equal to 0.5 mm. The height of each of the single tabs is a dimension of the single tab in a lead-out direction thereof.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of China patent application serial no. 202211256123.2, filed on Oct. 13, 2022. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The disclosure relates to the technical field of batteries, and in particular, relates to a cylindrical battery.

Description of Related Art

In the related art, the winding cell of the cylindrical battery is a winding type winding cell. The tabs on the winding cell may reliably contact the adjacent single tabs through bundling. However, due to the limitation of the tab structure, the flatness of the top portions of the tabs may be poor.

SUMMARY

The disclosure provides a cylindrical battery including a winding cell.

The winding cell includes a winding cell body and a first tab extending from one side of the winding cell body. The winding cell body is wound to form a central hole. In a radial direction of the central hole, the first tab includes a plurality of single tabs, and the plurality of single tabs form a first region.

Herein, heights of the plurality of single tabs in the first region gradually increase. A difference value between a maximum height difference value and a minimum height difference value between adjacent single tabs in the radial direction of the central hole is less than or equal to 0.5 mm. The height of each of the single tabs is a dimension of the single tab in a lead-out direction thereof.

DESCRIPTION OF THE EMBODIMENTS

The technical solutions in the exemplary embodiments of the disclosure will be described clearly and explicitly in conjunction with the drawings in the exemplary embodiments of the disclosure. The description proposed herein is just the exemplary embodiments for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that and various modifications and variations could be made thereto without departing from the scope of the disclosure.

In the description of the present disclosure, unless otherwise specifically defined and limited, the terms “first”, “second” and the like are only used for illustrative purposes and are not to be construed as expressing or implying a relative importance. The term “plurality” is two or more. The term “and/or” includes any and all combinations of one or more of the associated listed items.

In particular, a reference to “the” object or “a” and “an” object is intended to denote also one of a possible plurality of such objects. Unless otherwise defined or described, the terms “connect”, “fix” should be broadly interpreted, for example, the term “connect” can be “fixedly connect”, “detachably connect”, “integrally connect”, “electrically connect” or “signal connect”. The term “connect” also can be “directly connect” or “indirectly connect via a medium”. For the persons skilled in the art, the specific meanings of the abovementioned terms in the present disclosure can be understood according to the specific situation.

Further, in the description of the present disclosure, it should be understood that spatially relative terms, such as “above”, “below” “inside”, “outside” and the like, are described based on orientations illustrated in the figures, but are not intended to limit the exemplary embodiments of the present disclosure.

In the context, it should also be understood that when an element or features is provided “outside” or “inside” of another element(s), it can be directly provided “outside” or “inside” of the other element, or be indirectly provided “outside” or “inside” of the another element(s) by an intermediate element.

An embodiment of the disclosure provides a cylindrical battery. With reference toFIG.1toFIG.5, the cylindrical battery includes a winding cell20. The winding cell20includes a winding cell body21and a first tab22extending from one side of the winding cell body21. The winding cell body21is wound to form a central hole211. In a radial direction of the central hole211, the first tab22includes a plurality of single tabs221, and the plurality of single tabs221form a first region24. Herein, heights of the plurality of single tabs221in the first region24gradually increase. Further, a difference value between a maximum height difference value and a minimum height difference value between adjacent single tabs221in the radial direction of the central hole211is less than or equal to 0.5 mm. The height of each of the single tabs221is a dimension of the single tab221in a lead-out direction thereof.

The cylindrical battery provided by an embodiment of the disclosure includes the winding cell20. The winding cell20includes the winding cell body21and the first tab22extending from one side of the winding cell body21. Further, the winding cell body21is wound to form the central hole211. The first tab22may be formed by the plurality of single tabs221, and the plurality of single tabs221form the first region24. The heights of the plurality of single tabs221in the first region24gradually increase. Further, the difference value between the maximum height difference value and the minimum height difference value between adjacent single tabs221in the radial direction of the central hole211is less than or equal to 0.5 mm. In this way, when the single tabs221are bundled, top portions of the single tabs221may be substantially flush, so that the subsequent connection of the first tab22may be satisfied, and false connection may be avoided. The overall current-passing capability of the winding cell20is enhanced, and the performance of the cylindrical battery is thus improved.

It should be noted that the cylindrical battery is a wound battery, and the winding cell20may be wound on a winding cell structure. In this way, after the winding cell20is formed by winding, the winding cell structure is separated from the winding cell20, and the central hole211is thereby formed. For instance, the winding cell structure may be a cylinder, and a cylindrical central hole211is thereby formed.

After winding to form the winding cell20, the first tab22on the winding cell body21may be formed by the plurality of single tabs221, and at least part of the plurality of single tabs221is divided into the first region24. As shown inFIG.4, the heights of the plurality of single tabs221in the first region24gradually increase. Further, the difference value between the maximum height difference value and the minimum height difference value between adjacent single tabs221in the radial direction of the central hole211is less than or equal to 0.5 mm. When the plurality of single tabs221are bundled, that is, in the process of connecting the independent single tabs221together, the single tabs221with greater heights may be gathered towards the single tabs221with smaller heights. In this way, top ends of the plurality of single tabs221in the first region24are substantially flush with each other. As such, when the first tab22is subsequently connected to an external structure, the stability of the connection can be ensured. For instance, when the first tab22is welded to a terminal structure, a stable welding plane between the first tab22and the terminal structure may be ensured. False welding between the first tab22and the terminal structure is prevented from occurring, so that the current-passing capability between the first tab22and the terminal structure is improved. The connection between the first tab22and the terminal structure may be made through a connecting piece.

The height of each of the single tabs221is the dimension of the single tab221in the lead-out direction thereof. That is, the height of each of the single tabs221is an extension length of the single tab221. Further, it can be considered that the single tabs221are straightened in a centerline direction of the central hole211, and the dimension of each of the single tabs221in the centerline direction of the central hole211may be measured and obtained accordingly.

In an embodiment, the heights of the plurality of single tabs221in the first region24gradually increase to form an arithmetic progression. When the plurality of single tabs221are bundled, that is, in the process of connecting the independent single tabs221together, the single tabs221with greater heights may be gathered towards the single tabs221with smaller heights. In this way, the top ends of the plurality of single tabs221in the first region24are substantially flush with each other.

In an embodiment, in the radial direction of the central hole211, the heights of the plurality of single tabs221in the first region24gradually increase to form an arithmetic progression. That is, the height of the single tab221closest to the central hole211in the first region24is the smallest, and the height of the single tab221farthest from the central hole211in the first region24is the largest. When the plurality of single tabs221are gathered, it is necessary to make the single tabs221gather towards a direction close to the central hole211, so as to ensure that the top ends of the plurality of single tabs221in the first region24are substantially flush. The radial direction of the central hole211refers to the direction expanding outwards from the center of the central hole211.

In an embodiment, in the direction opposite to the radial direction of the central hole211, the heights of the plurality of single tabs221in the first region24gradually increase to form an arithmetic progression. That is, the height of the single tab221closest to the central hole211in the first region24is the largest, and the height of the single tab221farthest from the central hole211in the first region24is the smallest. When the plurality of single tabs221are gathered, it is necessary to make the single tabs221gather towards a direction away from the central hole211, so as to ensure that the top ends of the plurality of single tabs221in the first region24are substantially flush. The radial direction of the central hole211refers to the direction expanding outwards from the center of the central hole211. Therefore, the direction opposite to the radial direction of the central hole211is the direction extending from a peripheral outer edge of the winding cell body21to the center of the central hole211.

In an embodiment, a difference value between the single tab221with the largest height and the single tab221with the smallest height in the first region24≥0.08 mm. Therefore, by controlling the tolerance of the arithmetic progression formed by the plurality of single tabs221in the first region24, it can be ensured that the number of single tabs221in the first region24is quite large, so as to ensure that the first tab22can have a reliable thickness. In this way, during the welding process of the first tab22, the problem of the first tab22being welded through is avoided.

In an embodiment, the first tab22is a positive tab, and the tolerance of the arithmetic progression formed by the heights of the single tabs221in the first region24is 0.2 mm to 0.4 mm. Therefore, it can be ensured that the plurality of single tabs221can form a reliable positive tab, and the positive tab can have a relatively large height. Therefore, it is ensured that the positive tab can have a reliable current-passing capability, so that the positive tab can form a reliable connection with an external structure, and the safe use performance of the battery can be improved.

The first tab22is a positive tab, and the tolerance of the arithmetic progression formed by the heights of the single tabs221in the first region24may be 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, 0.3 mm, 0.33 mm, 0.35 mm, 0.38 mm, 0.39 mm, or 0.4 mm and so on.

In an embodiment, the first tab22is a negative tab, and the tolerance of the arithmetic progression formed by the heights of the plurality of single tabs221in the first region24is 0.1 mm to 0.3 mm. Therefore, it can be ensured that the plurality of single tabs221can form a reliable negative tab, and the negative tab can have a relatively small height. In this way, it is ensured that the negative tab can be conveniently connected to the external structure, and the forming efficiency of the cylindrical battery is improved.

The first tab22is a negative tab, and the tolerance of the arithmetic progression formed by the heights of the single tabs221in the first region24may be 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.23 mm, 0.25 mm, 0.28 mm, 0.29 mm, or 0.3 mm and so on.

It should be noted that the tolerance of the arithmetic progression formed by the heights of the plurality of single tabs221of the positive tab may be equal to the tolerance of the arithmetic progression formed by the heights of the plurality of single tabs221of the negative tab. Alternatively, the tolerance of the arithmetic progression formed by the heights of the plurality of single tabs221of the positive tab may be greater than the tolerance of the arithmetic progression formed by the heights of the plurality of single tabs221of the negative tab. After the single tabs are gathered, the height of the positive tab may be greater than that of the negative tab. The positive tab may be an aluminum tab, and the negative tab may be a copper tab, so as to meet the material requirements of the battery. When there is a height difference between the aluminum tab and the copper tab, it is convenient for the aluminum tab and the copper tab to be welded and connected to the aluminum connecting piece and the copper connecting piece respectively. Moreover, the welding stability may be ensured, and the problem of connection failure may be prevented from occurring. The aluminum tab may be connected to a casing structure10through the aluminum connecting piece, and the copper tab may be connected to the terminal structure through the copper connecting piece. Alternatively, the aluminum tab may be connected to the terminal structure through the aluminum connecting piece, and the copper tab may be connected to the casing structure10through the copper connecting piece. Alternatively, the aluminum tab may be connected to a first terminal structure through the aluminum connecting piece, and the copper tab may be connected to a second terminal structure through the copper connecting piece, which is not limited herein.

In an embodiment, the first region24is formed on one side of the first tab22close to the central hole211. The plurality of single tabs221further form a second region25, and the second region25is formed on the other side of the first tab22away from the central hole211. Herein, the heights of the plurality of single tabs221in the second region25are all equal. Therefore, when the plurality of single tabs221in the second region25are bundled, it can be ensured that the plurality of single tabs221in the second region25can have a relatively consistent gathering angle. In this way, a relatively flat top can be formed with the plurality of single tabs221in the first region24to the greatest extent.

The plurality of single tabs221in the first region24and the plurality of single tabs221in the second region25may be bundled in a direction close to the central hole211. The heights of the plurality of single tabs221in the first region24gradually increase to form an arithmetic progression, and the heights of the plurality of single tabs221in the second region25are all equal. Therefore, each of the single tabs221of the first tab22may be quickly bundled. Moreover, it can also be ensured that the top end of the first tab22has a relatively flat plane, so as to facilitate subsequent connection between the first tab22and the external structure.

The heights of the plurality of single tabs221in the second region25are substantially equal actually. That is, the heights of the plurality of single tabs221in the second region25can be considered to be equal when the inequalities caused by process errors and measurement errors are not included.

As shown inFIG.4, during the winding process of the winding cell20, the plurality of single tabs221in the first region24are wound first, and then the plurality of single tabs221in the second region25are wound.

In an embodiment, the heights of the single tabs221in the first region24is smaller than the height of the single tabs221in the second region25. Therefore, the single tabs221in the second region25may be bundled towards the single tabs221in the first region24. In this way, the top ends formed by the single tabs221are ensured to be relatively flat, and the height of the first tab22may be ensured, so that current-passing capability of the first tab22is ensured.

In an embodiment, a height difference between the height of the single tabs221in the second region25and the height of the single tab221in the first region24adjacent to the second region25is equal to the tolerance of the arithmetic progression formed by the heights of the plurality of single tabs221in the first region24. Therefore, it can be avoided that after the single tabs221in the second region25are bundled towards the single tabs221in the first region24, the top ends of the single tabs221in the second region25may be higher. This ensures that the top end of the first tab22formed by the plurality of single tabs221is relatively flat.

The battery includes a winding cell and an electrolyte, and the battery is the smallest unit capable of performing electrochemical reactions such as charging/discharging. The winding cell refers to a unit formed by winding a stacked part, and the stacked part includes a first electrode, a separator, and a second electrode. When the first electrode is a positive electrode, the second electrode is a negative electrode. The polarities of the first electrode and the second electrode may be interchanged.

As shown inFIG.4, a plurality of single tabs221are disposed on the first electrode or the second electrode. Herein, the plurality of single tabs221form the first region24and the second region25. During the winding process of the winding cell20, the first region24is wound first, and the second region25is wound later. Therefore, the heights of the plurality of single tabs221in the first region24gradually increase to form an arithmetic progression, and the heights of the plurality of single tabs221in the second region25are all consistent. Further, the heights of the plurality of single tabs221in the first region24and the first single tab221in the second region gradually increase to form an arithmetic progression. After winding the stacked part to form the winding cell20, the single tabs221are bundled to ensure that the top surface formed by each single tab221has a relatively high flatness.

It should be noted that the plurality of single tabs221may only form the first region24, and the heights of the plurality of single tabs221in the first region24gradually increase to form an arithmetic progression, so as to form the first tab22.

In an embodiment, as shown inFIG.2andFIG.3, the winding cell20further includes a second tab23. Polarities of the first tab22and the second tab23spaced apart from each other are opposite. The first tab22and the second tab23extend from a same side of the winding cell body21. On the basis of ensuring the insulation between the first tab22and the second tab23, the cumulative height of the first tab22and the second tab23may be reduced.

The first tab22and the second tab23have opposite polarities. One of the first tab22and the second tab23is a positive tab, and the other is a negative tab. By arranging the first tab22and the second tab23to extend from the same side of the winding cell body21, the problem of excessive accumulation of height space caused by the extension of the first tab22and the second tab23from opposite sides of the winding cell body21may be prevented from occurring.

In an embodiment, the first tab22is spaced apart from the second tab23in a circumferential direction of the central hole211. That is, the first tab22and the second tab portion23are spaced apart from each other around the central hole211in the circumferential direction. In this way, the connection area between the first tab22and the second tab23is increased to the greatest extent, and it is also ensured that the first tab22and the second tab23may have a reliable current-passing area.

Regarding the central hole, in an embodiment, as shown inFIG.2, one first tab22is provided, and one second tab23is provided. The first tab22and the second tab23are disposed in the circumferential direction of the central hole211. In this way, a simple structure is provided, and on the basis of ensuring the insulation gap between the first tab22and the second tab23, it can also be ensured that the first tab22and the second tab23have a reliable current-passing capability.

The first tab22is formed by multiple layers of single tabs, and each layer of single tabs may include one or more single tabs221. Herein, the heights of the plurality of single tabs221on the same layer may be consistent. The second tab23is formed by multiple layers of single tabs, and each layer of single tabs may include one or more single tabs. Herein, the heights of the plurality of single tabs on the same layer may be consistent.

In an embodiment, as shown inFIG.3, a plurality of first tabs22are provided, and a plurality of second tabs23are provided. The first tabs22and the second tabs23are arranged in an alternating manner in the circumferential direction of the central hole211. On the basis of ensuring the insulation gaps between the first tabs22and the second tabs23, it can be ensured that the first tabs22and the second tabs23have sufficient current-passing areas.

Note that a plurality of first tab portions22are provided, and a plurality of second tab portions23are provided. Herein, the first tabs22may form a plurality of first regions24and second regions25, and the heights of the single tabs221of different first regions24on the same layer may be the same. Correspondingly, the heights of the single tabs221in different second regions25located on the same layer may be consistent.

The arrangement of each single tab of the second tab23can refer to the arrangement of each single tab221of the first tab22. For instance, when the first tab22is a positive tab and the second tab23is a negative tab, the tolerance of the arithmetic progression formed by the heights of the plurality of single tabs221of the positive tab may be equal to the tolerance of the arithmetic progression formed by the heights of the plurality of single tabs221of the negative tab.

It should be noted that in some embodiments, it is not excluded that the first tab22and the second tab23may extend from opposite sides of the winding cell body21. In this case, both the first tab22and the second tab23may be ring-shaped. Certainly, it is not excluded that the first tab22and the second tab23may be non-closed structures in the circumferential direction.

In an embodiment, a distance between the first tab22and the central hole211is greater than 0, and a distance between the second tab23and the central hole211is greater than 0. In this way, the insulation capability between the first tab22and the second tab23may be improved.

It should be noted that, in some embodiments, it is not excluded that the distance between the first tab22and the central hole211may be equal to zero, and the distance between the second tab23and the central hole211may be equal to 0.

In an embodiment, the winding cell body21includes a plurality of stacked units, and the plurality of stacked units are wound to form the winding cell body21. The single tab221among the plurality of single tabs221closest to the central hole211is a first single tab. The single tab221among the plurality of single tabs221in the first region24farthest from the central hole211is a last single tab. The height of the first single tab is x, and the height of the highest single tab221is y, where y−x=(n−1) t. The last single tab is located on the nthstacked unit, and t is a thickness of the stacked unit, where y≤15 mm. On the basis of avoiding wrinkling and bending of the single tabs221during the bundling process, it can ensure that the top end of each single tab221has a better flatness. In this way, it is ensured that the first tab22can form reliable welding with the external structure.

As shown inFIG.4, the single tab221among the plurality of single tabs221closest to the central hole211is the first single tab. That is, the lowermost single tab221inFIG.4is the first single tab. The single tab221among the plurality of single tabs221in the first region24farthest from the central hole211is the last single tab. That is, the uppermost single tab221in the first region24inFIG.4is the last single tab of the first region24, and the last single tab is located on the nthstacked unit. The height of the first single tab is x, and the height y of the highest single tab221may be considered as the height of the single tabs221in the second region25. By setting y−x=(n−1) t, where t is the thickness of the stacked unit, it can be ensured that the first tab22can have a reasonable thickness. Therefore, the welding capability of the first tab22is improved, the problem of the first tab22being welded through is avoided, and the problem of false welding of the first tab22may also be prevented from occurring.

Note that as shown inFIG.5, the stacked units may include a first electrode212, a first separator213, a second electrode214, and a second separator215arranged in sequence. t is a sum of thicknesses of the first electrode212, the first separator213, the second electrode214, and the second separator215. Alternatively, it is not excluded that the stacked units may include the first electrode and the second electrode. The first electrode and the second electrode may be in direct contact, and t is the sum of the thicknesses of the first electrode and the second electrode.

In an embodiment, 5 mm≤y≤10 mm not only facilitates the bending of the first tab22but also ensures that the first tab22has a sufficient welding area. In this way, the electron transmission rate of the winding cell20is improved.

In an embodiment, as shown inFIG.1, the cylindrical battery further includes a terminal structure30. The terminal structure30may be disposed on the casing structure10. The winding cell20may be electrically connected to terminal structure30. For instance, the first tab22of the winding cell20may be electrically connected to terminal structure30. The terminal structure30may be insulated from the casing structure10, and the second tab23of the winding cell20may be electrically connected to the casing structure10.

The cylindrical battery may include two terminal structures30, and the first tab22and the second tab23of the winding cell20may be electrically connected to the two terminal structures30.

In an embodiment, the casing structure10may include a cover plate and a casing member. The terminal structure30may be disposed on the cover plate, and the casing member may be formed with an accommodating space. In this way, after the cover plate is connected to the casing member, the winding cell20may be effectively protected. The cover plate and the casing member may be welded, or the cover plate and the casing member may be riveted.

An embodiment of the disclosure further provides a battery apparatus including the abovementioned cylindrical battery.

The cylindrical battery of the battery apparatus provided by an embodiment of the disclosure includes the winding cell20. The winding cell20includes the winding cell body21and the first tab22extending from one side of the winding cell body21. Further, the winding cell body21is wound to form the central hole211. The first tab22may be formed by the plurality of single tabs221, and the plurality of single tabs221form the first region24. The heights of the plurality of single tabs221in the first region24gradually increase. Further, the difference value between the maximum height difference value and the minimum height difference value between adjacent single tabs221in the radial direction of the central hole211is less than or equal to 0.5 mm. In this way, when the single tabs221are bundled, top portions of the single tabs221may be substantially flush, so that the subsequent connection of the first tab22may be satisfied, and false connection may be avoided. The overall current-passing capability of the winding cell20is thereby enhanced, and the performance of the battery apparatus is thus improved.

In an embodiment, the battery apparatus is a battery module or a battery pack.

The battery module includes a plurality of cylindrical batteries. The battery module may also include a bracket, and the batteries may be fixed on the bracket.

The battery pack includes a plurality of cylindrical batteries and a box, and the box is configured to fix the cylindrical batteries.

Note that the battery pack includes cylindrical batteries, there may be a plurality of cylindrical batteries, and the plurality of cylindrical batteries are arranged in the box. Herein, the cylindrical batteries may be mounted in the box after forming a battery module. Alternatively, the cylindrical batteries may be directly arranged in the box, that is, the cylindrical batteries are not required to be arranged into groups, and the box is used to fix the cylindrical batteries.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. The disclosure is intended to cover any variations, uses or adaptations of the disclosure. These variations, uses, or adaptations follow the general principles of the disclosure and include common general knowledge or conventional technical means in the art that are not disclosed in the present disclosure. The specification and embodiments are illustrative, and the real scope and spirit of the present disclosure is defined by the appended claims.

It should be understood that the disclosure is not limited to the precise structures that have been described above and shown in the drawings, and various modifications and variations can be made without departing from the scope thereof. The scope of the disclosure is limited only by the appended claims.