Battery cell structure and battery

Abstract

The utility model relates to a battery cell structure and a battery. The battery cell structure comprises a roll core, a first pole piece, a second pole piece, a first lead and a second lead, the center of the roll core has a first folding area; the first folding area comprises a first pole piece layer located on the first pole piece and a second pole piece layer located on the second pole piece; the first pole piece layer is provided with a first pleating area capable of stretching in the winding direction of the winding core, and the first tab is located on the first pole piece layer and located outside the side, close to the winding starting end of the first pole piece layer, of the first pleating area; and / or, the second pole piece layer is provided with a second pleating area capable of stretching in the winding direction of the winding core, and the second pole lug is located on the second pole piece layer and located outside the side, close to the winding starting end of the second pole piece layer, of the second pleating area. According to the scheme provided by the invention, flexible adjustment and optimization of the positions of the tabs can be realized, and the battery cell packaging and welding problems caused by position deviation of the tabs are effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery preparation, and in particular to a battery cell structure and a battery. Background Art

[0002] In the production of consumer soft-pack lithium-ion batteries, winding technology is the mainstream method for manufacturing the core. Specifically, the winding process involves using a winding needle to clamp the positive and negative electrode sheets and wind them together with the separator. The tabs, as the key connection between the internal and external circuits, are crucial for battery packaging and pack welding.

[0003] In related technologies, the position of the tab on the electrode sheet is generally determined by the feeding position of the tab by the clamping end, that is, the position of the tab is fixed. When there is an error in the feeding position, the side distance, center distance and other distance parameters of the tab on the battery cell will have large deviations, which may easily lead to failure of the battery cell packaging, poor welding and other defects, and even cause battery swelling or abnormal charging and discharging functions, affecting the safety performance of the battery. Utility Model Content

[0004] In order to solve or partially solve the problems existing in the related art, the present application provides a battery cell structure and a battery, which can realize flexible adjustment and optimization of the tab position, effectively improve the battery cell packaging and welding problems caused by the tab position deviation, thereby reducing the probability of battery swelling and functional abnormality, and effectively improving the battery performance stability and safety of use.

[0005] A first aspect of the present application provides a battery cell structure, comprising: a winding core formed by winding a first pole piece, a separator, and a second pole piece, wherein the first pole piece is provided with a first pole tab, and the second pole piece is provided with a second pole tab;

[0006] The winding core has a first folding area at its center; the first folding area includes: a first pole piece layer located on the first pole piece, and a second pole piece layer located on the second pole piece;

[0007] Wherein, a first corrugated area that can be stretched and retracted in the winding direction of the winding core is provided on the first pole piece layer, and the first pole tab is located on the first pole piece layer and outside a side of the first corrugated area close to the winding starting end of the first pole piece layer; and / or,

[0008] A second corrugated area that can be stretched and retracted in the winding direction of the winding core is provided on the second pole piece layer. The second pole tab is located on the second pole piece layer and is located outside the side of the second corrugated area close to the winding starting end of the second pole piece layer.

[0009] In some embodiments, the first pole piece layer and the second pole piece layer each include a straight region parallel to the width direction of the winding core.

[0010] In some embodiments, the stretching range of the first pleated area is 2 mm to 5 mm.

[0011] In some embodiments, the second crimped area extends from 2 mm to 5 mm.

[0012] In some embodiments, the width of the first crumpled area along the thickness direction of the core when compressed is less than 0.5 mm.

[0013] In some embodiments, the width of the second corrugated area along the thickness direction of the core when compressed is less than 0.5 mm.

[0014] In some embodiments, the winding core has an arc area connected to the first folding area, a first spacing is set between the first pleating area and the arc area, and a second spacing is set between the second pleating area and the arc area, and the first spacing is the same as or different from the second spacing.

[0015] In some embodiments, a third distance is set between the first electrode tab and the first crimping area, a fourth distance is set between the second electrode tab and the second crimping area, and the third distance is greater than or equal to the fourth distance.

[0016] In some embodiments, the first crumpled area and the second crumpled area overlap or do not overlap along the thickness direction of the core.

[0017] A second aspect of the present application provides a battery, comprising: the battery cell structure described in the first aspect of the present application.

[0018] The technical solution provided by this application may have the following beneficial effects:

[0019] In the battery cell structure of the present application, the first electrode layer and the second electrode layer are respectively provided with a pleated area in the first folding area in the center of the core, so that the first electrode layer and the second electrode layer are allowed to be telescopically adjusted in the winding direction of the core, so that after the battery cell is completed, the position of the pole tab is adjusted by utilizing the above-mentioned telescopic mechanism, thereby realizing flexible adjustment and optimization of the pole tab position, which can effectively improve the battery cell packaging and welding problems caused by the deviation of the pole tab position, thereby reducing the probability of battery swelling and functional abnormality, and effectively improving the performance stability and safety of the battery; in addition, through the adjustable position of the pole tab, the battery cell structure of the present application can adapt to different battery cell sizes and pole tab position requirements, significantly improving the flexibility of battery manufacturing and the adaptability of the production line, and reducing the cost and time consumption increased by adjusting the pole tab position.

[0020] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the present application will become more apparent by describing in more detail exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0022] Figure 1 Schematic diagram of the structure of the battery cell shown in the embodiment of the present application;

[0023] Figure 2 This is another structural schematic diagram of the battery cell structure shown in an embodiment of the present application.

[0024] Reference numerals: 100, winding core; 110, first folding area; 120, arc area; 200, first pole tab; 300, second pole tab; 400, first pole piece layer; 410, first crimping area; 500, second pole piece layer; 510, second crimping area. DETAILED DESCRIPTION

[0025] The following describes embodiments of the present application in more detail with reference to the accompanying drawings. Although the accompanying drawings illustrate embodiments of the present application, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0026] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0027] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0028] Unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," and the like should be interpreted broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0029] In related technologies, the position of the tab on the electrode sheet is generally determined by the feeding position of the tab by the clamping end, that is, the position of the tab is fixed. When there is an error in the feeding position, the side distance, center distance and other distance parameters of the tab on the battery cell will have large deviations, which may easily lead to failure of the battery cell packaging, poor welding and other defects, and even cause battery swelling or abnormal charging and discharging functions, affecting the safety performance of the battery.

[0030] In response to the above problems, an embodiment of the present application provides a battery cell structure that can achieve flexible adjustment and optimization of the tab position, effectively improve the battery cell packaging and welding problems caused by tab position deviation, thereby reducing the probability of battery swelling and functional abnormalities, and effectively improving the battery performance stability and safety of use.

[0031] The technical solutions of the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0032] Figure 1 It is a structural schematic diagram of the battery cell structure shown in an embodiment of the present application.

[0033] See also Figure 1The battery cell structure of the present application includes a winding core 100 formed by winding a first electrode sheet, a diaphragm and a second electrode sheet. Specifically, the first electrode sheet, the diaphragm and the second electrode sheet are sequentially stacked and then wound to obtain the winding core 100. The first electrode sheet is provided with a first electrode tab 200, and the second electrode tab 300 is provided on the second electrode sheet. The center of the winding core 100 has a first folding area 110. The first folding area 110 may include a first electrode sheet layer 400 located on the first electrode sheet, and a second electrode sheet layer 500 located on the second electrode sheet. It can be understood that the first electrode sheet and the second electrode sheet correspond to different polarities, that is, the first electrode tab 200 and the first electrode sheet layer 400 and the second electrode tab 300 and the second electrode sheet layer 500 correspond to different polarities. The first electrode sheet layer 400 may be the first folded portion of the first electrode sheet located at the center of the winding core 100, and the second electrode sheet layer 500 may be the first folded portion of the second electrode sheet located at the center of the winding core 100. The first fold part refers to the first fold formed when the winding equipment clamps the head of the pole piece and winds it when the pole piece is wound.

[0034] The first electrode layer 400 is provided with a first crimping region 410 that can be stretched and contracted in the winding direction of the winding core 100, the first electrode tab 200 is located on the first electrode layer 400, and the first electrode tab 200 is located outside the side of the first crimping region 410 close to the winding starting end of the first electrode layer 400; and / or the second electrode layer 500 is provided with a second crimping region 510 that can be stretched and contracted in the winding direction of the winding core 100, the second electrode tab 300 is located on the second electrode layer 500, and the second electrode tab 300 is located outside the side of the second crimping region 510 close to the winding starting end of the second electrode layer 500. The first crimping region 410 and the second crimping region 510 can be formed by crimping the electrode using a crimping device, and the electrode portion located in the crimping region can be in a wavy sawtooth shape, so that the first crimping region 410 and the second crimping region 510 can be compressed and extended.

[0035] In the battery cell structure of the present application, the first crumpled area 410 is used to expand and contract in the winding direction of the core 100, and the second crumpled area is used to expand and contract in the winding direction of the core 100, so as to adjust the position of the first and second tabs 200 and 300 on the core 100. It is understood that the first crumpled area 410 or the second crumpled area 510 can be provided according to actual application requirements. For example, only the first crumpled area 410 or the second crumpled area 510 can be provided, so that only the position of the first tab 200 or only the second tab 300 can be adjusted; for another example, the first crumpled area 410 and the second crumpled area 510 can be provided at the same time, so that the positions of the first and second tabs 200 and 300 can be adjusted at the same time.

[0036] In this embodiment, the battery cell structure of the present application has a first electrode layer and a second electrode layer respectively provided with a pleated area in the first folding area in the center of the winding core, so that the first electrode layer and the second electrode layer are allowed to be telescopically adjusted in the winding direction of the winding core, so that after the battery cell is completed, the above-mentioned telescopic mechanism is used to adjust the position of the pole tab, thereby realizing flexible adjustment and optimization of the pole tab position, which can effectively improve the battery cell packaging and welding problems caused by the deviation of the pole tab position, thereby reducing the probability of battery swelling and functional abnormality, and effectively improving the performance stability and safety of the battery; in addition, through the adjustable position of the pole tab, the battery cell structure of the present application can adapt to different battery cell sizes and pole tab position requirements, significantly improving the flexibility of battery manufacturing and the adaptability of the production line, and reducing the cost and time consumption increased by adjusting the pole tab position.

[0037] It should be noted that stretching and contracting in the winding direction of the core 100 may refer to elongation or reverse compression in the winding direction, that is, through the first crimping area 410, the first pole piece layer 400 can be elongated or reverse compressed in the winding direction of the core. Similarly, through the second crimping area 510, the second pole piece layer 500 can be elongated or reverse compressed in the winding direction of the core.

[0038] In some embodiments, the first electrode layer 400 and the second electrode layer 500 each include a flat region parallel to the width direction of the winding core 100. It is understood that the flat regions on the first electrode layer 400 and the second electrode layer 500 are arranged parallel to each other, and the flat regions on the first electrode layer 400 and the second electrode layer 500 are parallel to the remaining electrode layers outside the first fold region 110. By setting the flat regions on the first electrode layer 400 and the second electrode layer 500, the impact of the first electrode layer 400 and the second electrode layer 500 on the overall electrical performance of the battery cell after expansion and contraction is effectively reduced.

[0039] In some embodiments, the stretching range of the first crumpled area 410 is 2 mm to 5 mm. That is, the compression distance or extension distance of the first crumpled area 410 is 2 mm to 5 mm. In some other embodiments, the stretching range of the second crumpled area 510 is 2 mm to 5 mm. Through the above-mentioned stretching range, the first pole piece layer 400 and the second pole piece layer 500 can move within an appropriate range, effectively preventing the instability of the battery cell structure caused by excessive movement range, and further ensuring the electrical performance of the battery cell. It should be noted that the stretching ranges of the first crumpled area 410 and the second crumpled area 510 can be the same or different.

[0040] In some embodiments, the width of the first crumpled region 410 along the thickness direction of the core 100 when compressed is less than 0.5 mm. In other embodiments, the width of the second crumpled region 510 along the thickness direction of the core 100 when compressed is less than 0.5 mm. It is understood that the width of the first crumpled region 410 or the second crumpled region 510 along the thickness direction of the core 100 will decrease when the first crumpled region 410 or the second crumpled region 510 is stretched, while the width of the first crumpled region 410 or the second crumpled region 510 along the thickness direction of the core 100 will increase when the first crumpled region 410 or the second crumpled region 510 is stretched. When the width of the first crumpled region 410 and the second crumpled region 510 along the thickness direction of the core 100 when compressed is less than 0.5 mm, the impact of the compressed first crumpled region 410 and the second crumpled region 510 on the battery cell structure can be effectively avoided. It should be noted that the width of the first crumpled region 410 and the second crumpled region 510 along the thickness direction of the core 100 when compressed can be the same or different.

[0041] In the battery cell structure of the present application, the corresponding pole tabs can be fixedly welded to the corresponding positions of the first pole piece layer 400 and the second pole piece layer 500 before winding, or part of the blank foil (blank foil refers to the foil not coated with active material) can be retained as the corresponding pole tabs when die-cutting the first pole piece or the second pole piece. After the winding is completed to form the battery cell, the position of the corresponding pole tabs is adjusted by clamping the pole tabs on the first pole piece layer 400 or the second pole piece layer 500 and moving them parallel to the width direction of the winding core 100. In particular, when there is a deviation in the position of the pole tabs after winding, such as a deviation in the side margins of the pole tabs or a deviation in the center distance of the pole tabs, the position of the pole tabs can be adjusted and optimized in the above manner, thereby effectively improving the battery cell packaging and welding problems caused by the deviation in the position of the pole tabs.

[0042] In some embodiments, the winding core 100 has an arc region 120 connected to the first folding region 110. It is understandable that the arc region 120 corresponds to the arc surface region formed by winding in the winding core, wherein the arc region 120 is prone to expansion during the later application of the battery cell. A first spacing is set between the first crumpled area 410 and the arc region 120, and a second spacing is set between the second crumpled area 510 and the arc region 120, and the first spacing is the same as or different from the second spacing. It is understandable that the first crumpled area 410 and the second crumpled area 510 are both spaced apart from the arc region 120, so that the first crumpled area 410 and the second crumpled area 510 are prevented from being in the arc region 120, thereby effectively avoiding the instability of the battery cell structure when the subsequent battery cell expands. Among them, the first spacing and the second spacing can be set according to actual application requirements.

[0043] In some embodiments, the first crumpled area 410 may overlap or not overlap with the second crumpled area 510 along the thickness direction of the winding core 100. That is, the relative positions of the first crumpled area 410 and the second crumpled area 510 in the thickness direction of the winding core 100 may be completely overlapping, partially overlapping, or not overlapping. In this way, the layout of the crumpled area can be more flexible, thereby adapting to the different adjustment requirements of different battery cells for the position of the tabs. It should also be noted that the first crumpled area 410 and the second crumpled area 510 will increase the thickness of the corresponding position of the battery cell to a certain extent during the compression process, and the pole piece will also increase the thickness of the corresponding position of the battery cell to a certain extent. By reasonably setting the positions of the first crumpled area 410, the second crumpled area 510, the first tab 200, and the second tab 300, the overall uniformity of the battery cell can be effectively improved, and the product performance of the battery cell can be further improved.

[0044] In some embodiments, a third spacing is provided between the first pole tab 200 and the first crimping region 410, and a fourth spacing is provided between the second pole tab 300 and the second crimping region 510, wherein the third spacing is greater than or equal to the fourth spacing. It can be understood that the first pole tab 200 and the second pole tab 300 correspond to the negative pole tab and the positive pole tab of the battery cell, respectively, that is, the first pole tab 200 and the second pole tab 300 are respectively located in the center area of ​​the winding core 100. By providing a spacing between the pole tabs and the crimping region on the same pole sheet layer, the initial positions of the first pole tab 200 and the second pole tab 300 can be closer to the center of the winding core. In this way, the adjustment distance of the corresponding pole tabs can be effectively reduced, further reducing the risk of adverse effects on the battery cell structure during the adjustment of the pole tab positions.

[0045] The present application also provides a battery, comprising the aforementioned battery cell structure of the present application.

[0046] Figure 2 This is another structural schematic diagram of the battery cell structure shown in an embodiment of the present application.

[0047] Please refer to Figure 2 As shown, the following takes the adjustment of the side distance of the first tab 200 from a to a' and the adjustment of the side distance of the second tab 300 from b to b' as an example to illustrate the process of adjusting the tab position of the battery cell structure in this application. The details are as follows:

[0048] like Figure 1 As shown, after the winding is completed, the initial side distance between the first pole tab 200 and one side of the winding core 100 is a, and the initial side distance between the second pole tab 300 and the same side of the winding core 100 is b. The first pole tab 200 and the second pole tab 300 are clamped by a clamping device and moved along the width direction parallel to the winding core 100 by a preset distance to adjust the positions of the first pole tab 200 and the second pole tab 300; as shown in FIG. Figure 2As shown, after the movement is completed, the side distance from the first tab 200 to the same side of the winding core 100 is a', and the side distance from the second tab 300 to the same side of the winding core 100 is b', where a>a', b>b'.

[0049] The scheme of the present application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the description are not necessarily required for this application. In addition, it is understood that the steps in the method of the embodiment of the present application can be adjusted in sequence, merged and deleted according to actual needs, and the modules in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs.

[0050] The embodiments of the present application have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A battery cell structure, characterized in that: include: A winding core formed by winding a first pole piece, a diaphragm, and a second pole piece, wherein the first pole piece is provided with a first pole tab, and the second pole piece is provided with a second pole tab; The winding core has a first folding area at its center; the first folding area includes: a first pole piece layer located on the first pole piece, and a second pole piece layer located on the second pole piece; Wherein, a first corrugated area that can be stretched and retracted in the winding direction of the winding core is provided on the first pole piece layer, and the first pole tab is located on the first pole piece layer and outside a side of the first corrugated area close to the winding starting end of the first pole piece layer; and / or, A second corrugated area that can be stretched and retracted in the winding direction of the winding core is provided on the second pole piece layer. The second pole tab is located on the second pole piece layer and is located outside the side of the second corrugated area close to the winding starting end of the second pole piece layer.

2. The battery cell structure according to claim 1, characterized in that: The first pole piece layer and the second pole piece layer each include a flat region parallel to the width direction of the winding core.

3. The battery core structure according to claim 1, characterized in that: The stretching range of the first pleated area is 2 mm to 5 mm.

4. The battery core structure according to claim 1, characterized in that: The stretching range of the second pleated area is 2 mm to 5 mm.

5. The battery core structure according to claim 1, characterized in that: When the first pleated area is compressed, the width distance along the thickness direction of the winding core is less than 0.5 mm.

6. The battery cell structure according to claim 1, characterized in that: When the second pleated area is compressed, the width distance along the thickness direction of the winding core is less than 0.5 mm.

7. The battery core structure according to claim 1, characterized in that: The winding core has an arc area connected to the first folding area, a first distance is set between the first pleated area and the arc area, a second distance is set between the second pleated area and the arc area, and the first distance is the same as or different from the second distance.

8. The battery core structure according to claim 1, characterized in that: A third distance is set between the first electrode tab and the first crimping area, a fourth distance is set between the second electrode tab and the second crimping area, and the third distance is greater than or equal to the fourth distance.

9. The battery core structure according to claim 1, characterized in that: The first crumpled area and the second crumpled area overlap or do not overlap along the thickness direction of the winding core.

10. A battery, characterized in that: include: The battery cell structure according to any one of claims 1 to 9.

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