CYLINDRICAL BATTERY

The disclosure relates to the technical field of batteries, and a cylindrical battery is provided, including: a single cell housing structure; a core, which is arranged in the single cell housing structure, and the core includes a core body, a first tab and a second tab, and the first tab and the second tab arranged at intervals extend out from the same end of the core body, and the core body is formed with a winding center; the first tab and the second tab are arranged along the circumferential direction of the winding center, and the length of the first tab is greater than the length of the second tab along the radial direction of the winding center. A certain distance may be set between the first tab and the second tab on basis that the first tab and the second tab are able to have sufficient current-passing capability.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of China patent application serial no. 202211256122.8, 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, in particular to a cylindrical battery.

Description of Related Art

In related art, a cylindrical battery may include tabs arranged at intervals. Due to structural limitations of the tabs, it is difficult to control the positional relationship between adjacent tabs, which results in an unreasonable layout.

SUMMARY

In the first aspect of the present disclosure, a cylindrical battery is provided, including: a single cell housing structure; a core, which is arranged in the single cell housing structure, and the core includes a core body, a first tab and a second tab, and the first tab and the second tab arranged at intervals extend out from the same end of the core body, and the core body is formed with a winding center; the first tab and the second tab are arranged along the circumferential direction of the winding center, and the length of the first tab is greater than the length of the second tab along the radial direction of the winding center.

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. Please refer toFIG.1toFIG.3. The cylindrical battery includes: a single cell housing structure10; a core20, the core is disposed in the single cell housing structure10, and the core20includes a core body21, a first tab22, and a second tab23, the first tab22and the second tab23disposed at intervals extend out from the same end of the core body21, and the core body21is formed with a winding center211; the first tab22and the second tab23are arranged along the circumferential direction of the winding center211, and the length of the first tab22is greater than the length of the second tab23along the radial direction of the winding center211.

The cylindrical battery in an embodiment of the disclosure includes a single cell housing structure10and a core20. The core20is arranged in the single cell housing structure10, and the core20includes a core body21, a first tab22and a second tab23. Through the configuration that the first tab22and the second tab23disposed at intervals are arranged along the circumferential direction of the winding center211, and the length of the first tab22is greater than the length of the second tab23along the radial direction of the winding center21, a certain distance may be set between the first tab22and the second tab23on basis that the first tab22and the second tab23are able to have sufficient current-passing capability. In this manner, the first tab22and the second tab23may be reasonably arranged on the core body21, so that it is possible to increase the space utilization of the core body21to improve the operation performance of the cylindrical battery.

It should be noted that the cylindrical battery includes a core and an electrolyte, the minimum unit capable of performing electrochemical reactions such as charging/discharging. The core refers to a unit formed by winding or laminating a stack portion including a first electrode sheet, a separator and a second electrode sheet. When the first electrode sheet is a positive electrode sheet, the second electrode sheet is a negative electrode sheet, and the polarities of the first electrode sheet and the second electrode sheet are interchangeable. The first electrode sheet and the second electrode sheet are coated with active material.

The cylindrical battery may be a wound battery, that is, the first electrode sheet, the second electrode sheet electrically opposite to the first electrode sheet, and the separator arranged between the first electrode sheet and the second electrode sheet are wound to obtain a wound core. After the wound core is formed, a winding center211is formed in the middle of the core body21, and the winding center211may be a circular hole. For example, when the first electrode sheet and the second electrode sheet are positive electrode sheet and negative electrode sheet respectively, positive tabs and negative tabs may also be formed on the first electrode sheet and the second electrode sheet, respectively.

The first tab22and the second tab23may be formed on the first electrode sheet and the second electrode sheet respectively, so that the first tab22and the second tab23form a positive tab and a negative tab respectively. The length of the first tab22is greater than the length of the second tab23along the radial direction of the winding center211. On the basis of ensuring that the first tab22has sufficient current-passing capability, it is convenient to control the insulation distance between the first tab22and the second tab23. For example, one side of the first tab22away from the winding center211and one side of the second tab23away from the winding center211are on the same circle of the core20. Under the circumstances, the other side of the first tab22close to the winding center211will be closer to the winding center211than the other side of the second tab23close to the winding center211. Therefore, the insulation distance between the first tab22and the second tab23may be increased to avoid the risk of insulation failure between the first tab22and the second tab23.

The first tab22and the second tab23may be formed on the first tab or the second tab simultaneously. Under the circumstances, the first tab22and the second tab23arranged at intervals may simultaneously form a positive tab or a negative tab. Moreover, the configuration that the length of the first tab22is greater than the length of the second tab23along the radial direction of the winding center211makes it possible for the first tab22and the second tab23to be arranged on the core body21in a more reasonable layout, so as to increase the current-passing capability of the first tab22and the second tab23.

There may be multiple radial directions of the winding center211, and the length of the first tab22may be obtained along the first radial direction of the winding center211, and the length of the second tab23may be obtained along the second radial direction of the winding center211. Further, the length of the first tab22may be considered as the distance between one side of the first tab22close to the winding center211and the other side of the first tab22away from the winding center211. The length of the second tab23may be considered as the distance between one side of the second tab23close to the winding center211and the other side of the second tab23away from the winding center211. The radial direction of the winding center211is indicated as a direction from the center of the winding center211toward the circumferential outer edge of the core body21.

In an embodiment, the length difference between the first tab22and the second tab23is 0.2 mm to 10 mm, so that the first tab22and the second tab23are reasonably arranged on the core body21. In this manner, the space utilization of the core body21is increased, and the insulation distance between the first tab22and the second tab23may be reasonably controlled, thereby improving the operation performance of the battery.

In an embodiment, as shown inFIG.3, the first tab22and the second tab23may be formed on the first electrode sheet and the second electrode sheet respectively. The structure shown inFIG.3is a structure formed by stacking the first electrode sheet and the second electrode sheet. It can be seen from the figure that the first single-piece tab221of the first tab22is led out first, and the second single-piece tab231of the second tab23is led out later. In this way, after the first tab22and the second tab23are formed by winding, the first tab22may be made closer to the winding center211, so that the length of the first tab22is greater than the length of the second tab23along the radial direction of the winding center211.

In an embodiment, along the radial direction of the winding center211, the first tab22includes a plurality of first single-piece tabs221, the second tab23includes a plurality of second single-piece tabs231, and the number of the first single-piece tab221is greater than the number of the second single-piece tab231. Accordingly, it is possible to make the length of the first tab22to be greater than the length of the second tab23, thereby increasing the current-passing capability of the first tab22.

A plurality of first single-piece tabs221may be gathered to form the first tab22, and a plurality of second single-piece tabs231may be gathered to form the second tab23. By making the number of the first single-piece tabs221greater than the number of the second single-piece tabs231, after a plurality of first single-piece tabs221and a plurality of second single-piece tabs231are gathered, it may be ensured that the length of the first tab22is greater than the length of the second tab23.

In an embodiment, along the radial direction of the winding center211, the first tab22includes a plurality of first single-piece tabs221, the second tab23includes a plurality of second single-piece tabs231. The cohesion of the plurality of first single-piece tabs221is greater than the cohesion of the plurality of second single-piece tabs231, and the length of the first tab22is greater than the length of the second tab23. Therefore, the first tab22may have higher connection strength than the second tab23, and the first tab22has a stronger current-passing capability, so that problems such as virtual welding will not occur easily, and the connection stability between the first tab22and the electrode lead-out structure may be ensured.

In an embodiment, along the radial direction of the winding center211, the first tab22includes a plurality of first single-piece tabs221, and the second tab23includes a plurality of second single-piece tabs231. The number of the first single-piece tabs221is not greater than the number of the second single-piece tabs231, and the cohesion of the plurality of first single-piece tabs221is lower than the cohesion of the plurality of second single-piece tabs231, so that the length of the first tab22is greater than the length of the second tab23. By controlling the cohesion of the plurality of first single-piece tabs221and the plurality of second single-piece tabs231, the length of the first tab22may also be made longer than that of the second tab23when the numbers are inconsistent. To some extent, it is possible to avoid the situation that the number of the first single-piece tabs221is too large, which leads to the problem that the core20is too heavy.

In an embodiment, along the radial direction of the winding center211, the first tab22includes a plurality of first single-piece tabs221, the second tab23includes a plurality of second single-piece tabs231, and the length of at least one of the first single-piece tabs221is greater than the length of the second single-piece tab231, so that the length of the first tab22may also be greater than the length of the second tab23. That is, the first single-piece tab221with a relatively long length may move closer to the position of the winding center211when being gathered, so that the first single-piece tab221may extend toward a position close to the winding center211, so as to increase the length dimension of the first tab22along the radial direction of the winding center211.

The length of the first single-piece tab221is the length of the first single-piece tab221along the direction in which it is led out, and the length of the second single-piece tab231is the length of the second single-piece tab231along the direction in which it is led out. The plurality of first single-piece tabs221need to be gathered to form the first tab22, and correspondingly, the plurality of second single-piece tabs231need to be gathered to form the second tab23.

The lead-out direction of the first single-piece tab221may be considered as the extending direction of the first single-piece tab221after the first single-piece tab221is straightened. Correspondingly, the lead-out direction of the second single-piece tab231may be considered as the extending direction of the second single-piece tab231after the second single-piece tab231is straightened. The extending direction of the first single-piece tab221and the extending direction of the second single-piece tab231are all parallel to the axial direction of the winding center211.

It should be noted that, along the radial direction of the winding center211, the length of the first tab22is greater than the length of the second tab23, and the lengths of the first tab22and the second tab23may be controlled by controlling the cohesion between the single-piece tabs. Alternatively, the lengths of the first tab22and the second tab23may be controlled by controlling the number of single-piece tabs. Alternatively, the lengths of the first tab22and the second tab23may be controlled by controlling the length of the single-piece tabs along the lead-out direction thereof.

The cohesion between the single-piece tabs may be considered as the pressing force formed between two adjacent single-piece tabs. When the pressing force between two adjacent single-piece tabs is relatively small, the cohesion is low. When the compressing force between two adjacent single-piece tabs is relatively large, the cohesion is high. For example, when the first tab22is formed by three first single-piece tabs221, and the second tab23is formed by three second single-piece tabs231, it is possible to make the pressing force between the three first single-piece tabs221to be relatively small, while the pressing force between the three second single-piece tabs231to be relatively large. In this manner, the cohesion between the three first single-piece tabs221may be made lower than the cohesion between the three second single-piece tabs231, so that the length of the first tab22is greater than the length of the second tab23along the radial direction of the winding center211.

For example, when the first tab22is formed by three first single-piece tabs221, and the second tab23is formed by three second single-piece tabs231, the length of the three first single-piece tabs221along the lead-out direction thereof should be greater than the length of the three second single-piece tabs231along the lead-out direction thereof. Under the circumstances, when the three first single-piece tabs221are gathered, the three first single-piece tabs221may be entirely extended toward the direction of the winding center211, correspondingly, the three second single-piece tabs231may also be entirely extended toward the direction of the winding center211. However, since the length of the first single-piece tabs221along the lead-out direction thereof is greater than the length of the second single-piece tabs231along the lead-out direction thereof, it is possible to make the extending length of the three first single-piece tabs221toward the winding center211to be greater than the extending length of the three second single-piece tabs231toward the winding center211. In this manner, it is possible to make the length of the first tab22to be greater than the length of the second tab23along the radial direction of the winding center211.

In some embodiments, it is not excluded that the thickness of the first single-piece tab221may be greater than the thickness of the second single-piece tab231. Therefore, even if the number of the first single-piece tab221is consistent with the number of the second single-piece tab231, the cohesion of the first single-piece tab221is consistent with the cohesion of the second single-piece tab231, and the length of the first single-piece tab221is consistent with the length of the second single-piece tab231, it may still be ensured that the length of the first tab22is greater than the length of the second tab23along the radial direction of the winding center211.

In an embodiment, the polarities of the first tab22and the second tab23are the same, that is, the first tab22and the second tab23may form a positive tab or a negative tab simultaneously.

In an embodiment, the polarities of the first tab22and the second tab23are opposite, that is, one of the first tab22and the second tab23forms a positive tab, and the other forms a negative tab.

In an embodiment, the first tab22forms a part of the positive tab. Along the winding direction of the core body21, the positive tab includes a plurality of positive tab layers arranged at intervals, and the distance between the adjacent positive tab layers gradually increases first, then gradually decreases, and finally increases again. The tab layer includes one or more positive single-piece tabs, so that a longer first tab22may be formed on the core body21.

Along the winding direction of the core body21, the positive tab includes a plurality of positive tab layers arranged at intervals, that is, one positive tab layer or at least two positive tab layers may be included on each circle of the positive tab. For example, when the positive tab may only include a first tab22with a long length, a positive tab layer may be provided on a circle of the positive tab close to the winding center211. During the process, as the radius of each circle gradually increases, the distance between adjacent positive tab layers gradually increases first. After a certain number of circles are formed by winding, a plurality of positive tab layers arranged at intervals may be provided on one circle. During the process, since there are one positive tab layer to multiple positive tab layers on one circle, although the radius on the corresponding circle increases, the distance between adjacent positive tab layers will decrease. However, as the radius of each circle formed subsequently increases gradually, the distance between adjacent positive tab layers finally increases gradually. During this process, a first tab22with a longer length may be formed, and a tab with a shorter length may be formed as well.

In an embodiment, the second tab23forms a part of the negative tab. Along the winding direction of the core body21, the negative tab includes a plurality of negative tab layers arranged at intervals. The distance between adjacent negative tab layers first gradually increases, then gradually decreases, and finally increases again. The negative tab layer includes one or more negative single-piece tabs, so that at least one second tab23with a shorter length may be formed on the core body21.

Along the winding direction of the core body21, the negative tab includes a plurality of negative tab layers arranged at intervals, that is, one negative tab layer or at least two negative tab layers may be included on each circle of the negative tab. For example, when the negative tab may only include a second tab23with a short length, a negative tab layer may be provided on a circle of the negative tab close to the winding center211. During the process, as the radius of each circle gradually increases, the distance between adjacent negative tab layers gradually increases first. After a certain number of circles are formed by winding, a plurality of negative tab layers arranged at intervals may be provided on one circle. During the process, since there are one negative tab layer to multiple negative tab layers on one circle, although the radius on the corresponding circle increases, the distance between adjacent negative tab layers will decrease. However, as the radius of each circle formed subsequently increases gradually, the distance between adjacent negative tab layers finally increases gradually. During this process, a tab with a longer length may be formed, and a tab23with a shorter length may be formed as well.

In an embodiment, the first tab22forms a part of the positive tab, the second tab23forms a part of the negative tab, and the core20is formed by winding a winding unit. Along the winding direction of the core body21, the winding unit includes a plurality of tab layers arranged at intervals. The distance between adjacent tab layers increases gradually at first, then decreases gradually, and finally increases again. The tab layer includes one or more single-piece tabs.

The winding unit may include a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and the negative electrode sheet are stacked, and a separator may be arranged between the positive electrode sheet and the negative electrode sheet. The winding unit includes a plurality of tab layers arranged at intervals. The tab layer includes a positive tab layer and a negative tab layer. There may be multiple positive tab layers arranged at intervals on the positive electrode sheet, and there may be multiple negative tab layers arranged at intervals on the negative electrode sheet. After straightening the winding unit, it can be seen that the positive tab layer and the negative tab layer are arranged at intervals, and the positive tab layer and the negative tab layer are alternately arranged. The overall forming trend of the distance between the positive tab layer and the negative layer may be gradually increased first, then gradually decreased, and finally increased again. Finally, a first tab22with a longer length, a second tab23with a shorter length, and other tabs may be formed on the core body21, which are not limited here.

It should be noted that, in combination with what is shown inFIG.4,FIG.4may indicate an arrangement trend diagram of positive tab layers, where X may represent the extending direction of multiple positive tab layers, Y may represent the distance between adjacent positive tab layers, and S shows the variation trend of the distance between the positive tab layers. Correspondingly,FIG.4may also represent an arrangement trend diagram of negative tab layers, where X may represent the extending direction of multiple negative tab layers, Y may represent the distance between adjacent negative tab layers, and S shows the variation trend of the distance between the negative tab layers.

Correspondingly,FIG.4may also represent an arrangement trend diagram of tab layers of the winding unit, where X may represent the extending direction of multiple tab layers, Y may represent the distance between adjacent tab layers, and S shows the variation trend of the distance between the tab layers.

The reason thatFIG.4can be used to represent the variation trends of the above three different distances is the illustration is made on the basis of not taking specific distance values into consideration, andFIG.4is only used to display the variation trends of distances.

In an embodiment, as shown inFIG.2, there are two second tabs23, and the first tab22is located between the two second tabs23. On the basis of ensuring a reliable insulation distance between the second tab23and the first tab22, the current-passing capability of the second tab23may be ensured.

In an embodiment, as shown inFIG.2, the core20further includes a third tab24, the polarity of the third tab24is the same as that of the second tab23. The length of the third tab24is greater than that of the second tab23along the radial direction of the winding center211, so that the current-passing capability of the second tab23and the third tab24with the same polarity may be further increased, and the connection strength with the electrode lead-out structure may be improved.

In an embodiment, as shown inFIG.2, the core20further includes two fourth tabs25, the polarity of the fourth tab25is the same as that of the first tab22, and the third tab24is located between two fourth tabs25. The length of the fourth tab25is shorter than the length of the first tab22along the radial direction of the winding center211. On the basis of ensuring that the first tab22and the fourth tab25have a reliable current-passing capability, the fourth tab25and the third tab24may also have a reliable insulation capability.

In an embodiment, the distances between the first tab22, the second tab23, the third tab24, and the fourth tab25and the winding center211are all greater than zero. The first tab22and the fourth tab25have the same polarity, the first tab22and the third tab24have the same polarity, and the first tab22and the second tab23have opposite polarities.

In an embodiment, the first tab22and the second tab23are arranged along the circumferential direction of the winding center211. Such configuration not only has a simple structure, and on basis of ensuring the insulation gap between the first tab22and the second tab23, it is also possible to ensure that the first tab22and the second tab23have a reliable current-passing capability.

As shown inFIG.2, the first tab22, the second tab23, the fourth tab25, the third tab24, the fourth tab25, and the second tab23may be arranged along the circumferential direction of the winding center211, so that the first tab22and the two fourth tabs25are used to form positive tabs, and the two second tabs23and third tabs24may be used to form negative tabs, or, the first tab22and the two fourth tabs25are used to form negative tabs, and the two second tabs23and third tabs24may be used to form positive tabs.

In an embodiment, the area of the end surface of the first tab22away from the core body21is larger than the area of the end surface of the second tab23away from the core body21, so that a large contact area is formed between the first tab22and the electrode lead-out structure, so as to increase the current-passing capability between the first tab22and the electrode lead-out structure.

The area of the end surface of the first tab22away from the core body21is larger than the area of the end surface of the fourth tab25away from the core body21, and the area of the end surface of the third tab24away from the core body21is larger than the area of the end surface of the second tab23away from the core body21.

It should be noted that, taking the core20inFIG.2as an example, the first tab22and the two fourth tabs25are provided to form positive tabs, while the two second tabs23and the third tab24may be provided to form negative tabs. Under the circumstances, along the winding direction of the core body21, the positive tab includes a plurality of positive tab layers arranged at intervals, and the distance between adjacent positive tab layers gradually increases first, and then gradually decreases, and finally increases gradually. Along the winding direction of the core body21, the negative tab includes a plurality of negative tab layers arranged at intervals, the distance between adjacent negative tab layers gradually increases first, and then gradually decreases, and finally increases gradually. In this manner, after the core20is formed by winding, the core20as shown inFIG.2may be formed.

In an embodiment, as shown inFIG.1, the cylindrical battery further includes a pole structure30, which may be arranged on the single cell housing structure10, and the core20may be electrically connected with the pole structure30. For example, the first tab22of the core20may be electrically connected to the pole structure30, and the pole structure30may be insulated from the single cell housing structure10, and the second tab23of the core20may be electrically connected to the single cell housing structure10.

The cylindrical battery may include two pole structures30, and the first tab22and the second tab23of the core20may be electrically connected to the two pole structures30respectively.

In an embodiment, the single cell housing structure10may include a cover plate and a housing part. The pole structure30may be disposed on the cover plate, and the housing part may be formed with an accommodation space, so that after the cover plate and the housing part are connected, it is possible to provide effective protection for the core20. The cover plate and housing parts may be welded together, or the cover plate and housing parts may be riveted together.

An embodiment of the present disclosure further provides a battery assembly, including the above-mentioned cylindrical battery.

The cylindrical battery of the battery pack of an embodiment of the present disclosure includes a single cell housing structure10and a core20. The core20is disposed in the single cell housing structure10. The core20includes a core body21, a first tab22and a second tab23. By making the first tab22and the second tab23arranged at intervals be arranged along the circumferential direction of the winding center211, and the length of the first tab22is greater than the length of the second tab23along the radial direction of the winding center211, on basis of ensuring that the first tab22and the second tab23have sufficient current-passing capability, it is possible to provide a certain distance between the first tab22and the second tab23. In this way, the first tab22and the second tab23are reasonably arranged on the core body21to increase the space utilization of the core body21and improve the operation performance of the battery assembly.

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

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

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

It should be noted that the battery pack includes the cylindrical battery, and there may be a plurality of cylindrical batteries. The plurality of cylindrical batteries are placed in the box body. A plurality of cylindrical batteries may be disposed in the box body after forming into a battery module. Alternatively, a plurality of cylindrical batteries may be directly disposed in the box body, that is, it is not necessary to group the plurality of cylindrical batteries together, and the box body may be used to fix the plurality of 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.