Multi-roll-core battery

Abstract

The utility model discloses a multi-roll-core battery which comprises a shell and a plurality of roll-core cells, the plurality of roll-core cells are arranged in the shell and are electrically connected, each roll-core cell comprises a straight part and arc parts which are respectively connected to opposite sides of the straight part, and the arc parts are arranged in the shell. Wherein one arc part comprises a main body branch part and at least one tab branch part, and the peripheral surface of the tab branch part and the peripheral surface of the main body branch part form the peripheral surface of the arc part or the part of the tab branch part extends out of the peripheral surface of the main body branch part; and the tab part of one winding battery cell is electrically connected to the tab part of at least one of the remaining winding battery cells. According to the multi-roll-core battery, the energy density can be improved, and the safety performance is improved. The utility model is applied to the field of energy storage elements.

Description

Technical Field

[0001] The utility model relates to the field of energy storage elements, in particular to a multi-roll core battery. Background Art

[0002] As the main core component of new energy vehicles, lithium-ion batteries have one of the main research and development directions of improving energy density and safety performance. For lithium-ion batteries, their energy density and safety performance mainly depend on the internal winding core, which is generally composed of positive electrode sheets, separators, negative electrode sheets, and separators wound or stacked in sequence.

[0003] In the related art, due to the large volume effect of the silicon negative electrode during the charging process, the battery cell will expand locally and generate heat during the cycle process, and black spots and lithium precipitation will appear at the rounded corners as the battery cell structure is wound, which will affect the safety of use and the stability of the structure. In addition, when the battery pack is formed into a battery, the shell of a single battery will also occupy a certain space, resulting in a reduction in the space inside the battery pack and a lower energy density. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a multi-roll core battery, which can improve energy density and safety performance.

[0005] The multi-roll core battery according to the embodiment of the utility model comprises:

[0006] shell;

[0007] A plurality of wound battery cells are provided in the shell and are electrically connected. The wound battery cells include a straight portion and arc portions respectively connected to opposite sides of the straight portions, wherein one of the arc portions includes a main body section and at least one tab section, the outer circumferential surface of the tab section together with the outer circumferential surface of the main body section forms the outer circumferential surface of the arc portion or a portion of the tab section extends out of the outer circumferential surface of the main body section, and the tab section of one of the wound battery cells is electrically connected to the tab section of at least one of the remaining wound battery cells.

[0008] The multi-roll core battery of the first embodiment of the utility model has at least the following beneficial effects:

[0009] 1. By arranging multiple wound cells in the shell, the shell thickness of the single wound cell is omitted, saving space; and the multiple wound cells are electrically connected in the shell, so that the wound cells can be connected as a whole for charging and discharging, and can maintain the original energy. When the space of the multi-wound core battery is reduced and the energy remains unchanged, the energy density of the multi-wound core battery is increased;

[0010] 2. The wound battery cells are electrically connected through the pole ear sections of the arc portion, so that the two end surfaces of the wound battery cells along the axial direction of the arc portion are not blocked, which can better dissipate heat, thereby improving the heat dissipation effect of the multi-core battery and improving safety performance.

[0011] According to some embodiments of the utility model, both of the two arc portions are provided with the pole lug division, the pole lug division of one arc portion is the first pole lug division, and the pole lug division of the other arc portion is the second pole lug division, the polarity of the first pole lug division is opposite to that of the second pole lug division, and the first pole lug division of one of the wound battery cells is electrically connected to the first pole lug division or the second pole lug division of at least one of the remaining wound battery cells.

[0012] According to some embodiments of the utility model, the arc portion is provided with two pole lug divisions with opposite polarities, namely a first pole lug division and a second pole lug division, and the first pole lug division of a wound battery cell is electrically connected to the first pole lug division or the second pole lug division of at least one of the remaining wound battery cells.

[0013] According to some embodiments of the utility model, the arc portion is provided with a pole lug portion, the pole lug portion is a first pole lug portion, the straight portion is provided with a second pole lug portion extending axially along the arc portion, the polarity of the first pole lug portion is opposite to that of the second pole lug portion, and the first pole lug portion of the wound battery cell is electrically connected to the first pole lug portion or the second pole lug portion of at least one of the remaining wound battery cells.

[0014] According to some embodiments of the present invention, the first tab portion of one of the wound battery cells is electrically connected to the second tab portion of another of the wound battery cells, so that a plurality of the wound battery cells are sequentially connected in series.

[0015] According to some embodiments of the utility model, if part of the pole lug division extends out of the outer peripheral surface of the main body division, along the stacking direction of the straight portion, the arc portion also includes a pole lug space parallel to the pole lug division, part of the first pole lug division is located in the second pole lug space corresponding to the second pole lug division, part of the second pole lug division is located in the first pole lug space corresponding to the first pole lug division, and the first pole lug division is directly electrically connected to the second pole lug division.

[0016] According to some embodiments of the utility model, one wound battery cell or multiple wound battery cells are connected in series to form a parallel group, the number of the parallel groups is multiple, the parallel group includes a first total pole lug division and a second total pole lug division, all of the first total pole lug divisions of the parallel group are electrically connected to each other, and all of the second total pole lug divisions are electrically connected to each other, so that all of the parallel groups are connected in parallel.

[0017] According to some embodiments of the present invention, it further includes: a first connecting member, and all the first tab sections of the parallel group are electrically connected to the first connecting member.

[0018] According to some embodiments of the present invention, if part of the first pole lug division extends out of the outer circumference of the corresponding first main body division, the part of the first pole lug division of a wound battery cell that extends out of the outer circumference of the first main body division is directly electrically connected to the first pole lug division or the second pole lug division of at least one of the remaining wound battery cells.

[0019] According to some embodiments of the present invention, it further includes: a connecting member, through which the tab portion of one of the wound battery cells is indirectly electrically connected to the tab portion of at least one of the remaining wound battery cells.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 It is a structural schematic diagram of a first implementation mode of a wound cell of a multi-roll-core battery according to an embodiment of the utility model;

[0023] Figure 2 It is a structural schematic diagram of a second implementation mode of a wound cell of a multi-roll-core battery of an embodiment of the utility model;

[0024] Figure 3 It is a structural schematic diagram of a third implementation mode of a wound cell of a multi-roll-core battery according to an embodiment of the utility model;

[0025] Figure 4 It is a structural schematic diagram of a fourth implementation mode of a wound cell of a multi-roll-core battery according to an embodiment of the utility model;

[0026] Figure 5 It is a structural schematic diagram of a fifth implementation mode of a wound cell of a multi-roll-core battery according to an embodiment of the utility model;

[0027] Figure 6 This is a schematic diagram of the structure of electrode connections in a second implementation manner of a wound cell of a multi-roll-core battery in an embodiment of the utility model, a) is a parallel schematic diagram, and b) is a series schematic diagram.

[0028] Figure Number:

[0029] Housing 100;

[0030] Wound battery cell 200; straight portion 210; arc portion 220; main body portion 221; tab portion 222;

[0031] Connector 300. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0033] In the description of the present invention, it should be understood that the descriptions involving orientation, such as the orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In the description of the present utility model, "several" refers to one or more, and "multiple" refers to two or more. If there is a description of "first" or "second", it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0035] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0036] In the related art, the method of making a wound battery cell is as follows: after stacking the positive electrode sheet, diaphragm, negative electrode sheet and diaphragm, the winding piece fixes one end of the two diaphragms and rotates to form a spiral winding body. When the winding piece is a square piece, the wound battery cell will form a straight portion of the electrode sheet and the diaphragm stacked straight in the square area of ​​the square piece, and the two sides of the square piece will form two arc portions of the electrode sheet and the diaphragm bending respectively. During the battery charging process, the silicon negative electrode coating used in the negative electrode sheet has a large volume effect, which makes the silicon negative electrode coating easy to expand and generate stress; during the battery cycle, the heat of the arc portion will not dissipate, causing the heat of the arc portion to concentrate and cause black spot lithium precipitation, which will affect the safety of use and the stability of the structure. In addition, when the battery pack forms a battery, the outer shell of a single battery will also occupy a certain space, resulting in a reduction in the space inside the battery pack and a reduction in energy density.

[0037] Reference Figures 1 to 5 As shown, a multi-core battery of an embodiment of the utility model comprises: a shell 100 and a plurality of wound battery cells 200, wherein the plurality of wound battery cells 200 are all arranged in the shell 100, and the plurality of wound battery cells 200 are electrically connected, the wound battery cells 200 comprise a straight portion 210 and an arc portion 220 respectively connected to opposite sides of the straight portion 210, wherein an arc portion 220 comprises a main body portion 221 and at least one tab portion 222, the outer peripheral surface of the tab portion 222 together with the outer peripheral surface of the main body portion 221 forms the outer peripheral surface of the arc portion 220 or a portion of the tab portion 222 extends out of the outer peripheral surface of the main body portion 221, the tab portion 222 of a wound battery cell 200 is electrically connected to the tab portion 222 of at least one of the remaining wound battery cells 200, and the multi-core battery can improve the energy density and improve the safety performance.

[0038] It should be noted that the method for forming the ear portion 222 of the arc portion 220 on the wound battery cell 200 is as follows: first, when making the electrode sheet, the electrode sheet includes a current collector and a coating applied to the surface of the current collector, the coating portion of the current collector is rectangular, and within the rectangular outline of the coating portion of the current collector, a blank area is reserved without coating; when the positive electrode sheet, the diaphragm, the negative electrode sheet and the diaphragm are stacked to form a stack, if a positive electrode blank area is provided on the positive electrode sheet, then the portions of the two diaphragms and the negative electrode sheet corresponding to the positive electrode blank area are rubbed and cut, and only the current collector will exist in this portion; then, the stack is wound around the winding member to form the wound battery cell 200. After winding, at least one layer of the blank area is located on the outer circumference of the arc portion 220, the coating portion of the arc portion 220 forms the main portion 221, and the portion where the blank area is located forms the ear portion 222.

[0039] The two ends of the blank area along the length direction of the current collector are connected to the current collector, and the current collector is provided with a plurality of blank areas along its length direction, and the plurality of blank areas are formed in the arc portion 220, and the plurality of blank areas are sequentially stacked along the radial direction of the arc portion 220 to form a tab portion 222, at which time, the outer circumference of the tab portion 222 forms a part of the outer circumference of the arc portion 220. When there is only one blank area, the outer circumference of the tab portion 222 formed by the blank area forms a part of the outer circumference of the arc portion 220.

[0040] Among them, only one end of the blank area along the length direction of the current collector is connected to the current collector, and the current collector is provided with multiple blank areas along its own length direction, and multiple blank areas are formed in the arc portion 220, and multiple blank areas extend out of the outer peripheral surface of the main body division 221 in the direction away from the straight portion 210, and then form the tab division 222, at this time, part of the tab division 222 extends out of the outer peripheral surface of the main body division 221. When there is only one blank area, part of the tab division 222 formed by the blank area extends out of the outer peripheral surface of the main body division 221.

[0041] It is worth understanding that when the arc portion 220 of the wound battery cell 200 is formed with a tab division 222, the tab divisions 222 of the plurality of wound battery cells 200 can be electrically connected first, and then installed in the housing 100 to form a multi-wound battery. Multiple wound battery cells 200 are arranged in the housing 100, eliminating the shell thickness of the single wound battery cell 200 and saving space; the plurality of wound battery cells 200 are electrically connected in the housing 100, so that the wound battery cells 200 can be connected as a whole for charging and discharging, and can maintain the original energy. When the space of the multi-wound battery is reduced and the energy remains unchanged, the energy density of the multi-wound battery is increased; the wound battery cell 200 is electrically connected through the tab division 222 of the arc portion 220, so that the two end faces of the wound battery cell 200 along the axial direction of the arc portion 220 are not blocked, and heat can be better dissipated, thereby improving the heat dissipation effect of the multi-wound battery and improving safety performance.

[0042] Moreover, the two diaphragms corresponding to the positive electrode blank area and the cut parts of the negative electrode sheet will also form extra space for the negative electrode coating of the negative electrode sheet to expand, reduce stress concentration, and accommodate more heat, thereby improving the heat dissipation effect of the wound battery cell 200, thereby improving the heat dissipation effect of the multi-roll core battery and improving safety performance. In addition, when the two ends of the blank area along the length direction of the current collector are connected to the current collector, and at least one of the two sides of the blank area along the width direction of the current collector is separated from the current collector, or only one end of the blank area along the length direction of the current collector is connected to the current collector, there will be a gap between the ear section 222 and the main body section 221, and the arc section 220 can dissipate heat in the area where the outer peripheral surface of the arc section 220 is located through this gap, further improving the heat dissipation effect of the multi-roll core battery and improving safety performance.

[0043] In this embodiment, the housing 100 may be a flexible housing to form a soft-pack battery cell; or the housing 100 may be a hard housing to form a square battery cell.

[0044] Reference Figure 1 As shown, in some specific embodiments of the present invention, both arc portions 220 are provided with a pole lug division 222, the pole lug division 222 of one arc portion 220 is a first pole lug division, and the pole lug division 222 of the other arc portion 220 is a second pole lug division, the polarity of the first pole lug division is opposite to that of the second pole lug division, and the first pole lug division of a wound battery cell 200 is electrically connected to the first pole lug division or the second pole lug division of at least one of the remaining wound battery cells 200.

[0045] Specifically, when the first tab section of a wound cell 200 is connected to the second tab section of another wound cell 200, the wound cells 200 are connected in series, and at this time, the plurality of wound cells 200 are electrically connected in sequence through the first tab section and the second tab section. When the first tab section of a wound cell 200 is connected to the first tab section of at least one wound cell 200, the plurality of wound cells 200 are connected in parallel, and the second tab section of the wound cell 200 will also be connected to the second tab section of the corresponding wound cell 200.

[0046] In this embodiment, when the wound cells 200 are connected in series, the multiple wound cells 200 are connected in sequence and are distributed in a straight line or a serpentine shape. When the wound cells 200 are connected in parallel, the parallel wound cells 200 are arranged in sequence along the stacking direction of the straight portion 210 to form a rectangular module. At this time, the first tab portions of all parallel wound cells 200 are located on one side of the rectangular module, and all the first tab portions are electrically connected, and the second tab portions are located on the other opposite side of the rectangular module, and all the second tab portions are electrically connected.

[0047] Reference Figure 2 and Figure 6 As shown, in some specific embodiments of the present invention, an arc portion 220 is provided with two pole lug divisions 222 with opposite polarities, namely a first pole lug division and a second pole lug division, and the first pole lug division of a wound battery cell 200 is electrically connected to the first pole lug division or the second pole lug division of at least one of the remaining wound battery cells 200.

[0048] Specifically, when the first tab section of a wound cell 200 is connected to the second tab section of another wound cell 200, the wound cells 200 are connected in series, and at this time, the plurality of wound cells 200 are electrically connected in sequence through the first tab section and the second tab section. When the first tab section of a wound cell 200 is connected to the first tab section of at least one wound cell 200, the plurality of wound cells 200 are connected in parallel, and the second tab section of the wound cell 200 will also be connected to the second tab section of the corresponding wound cell 200.

[0049] In this embodiment, refer to Figure 6As shown in b), when the wound battery cells 200 are connected in series, a plurality of wound battery cells 200 are connected in sequence, and the wound battery cells 200 in series are arranged in sequence along the stacking direction of the straight portion 210 to form a rectangular module, the first pole lug section and the second pole lug section are located on the same side of the rectangular module, the first pole lug section and the second pole lug section of two adjacent wound battery cells 200 are in opposite positions, or the first pole lug sections of two adjacent wound battery cells 200 have opposite polarities, the first pole lug section of one wound battery cell 200 is connected to the second pole lug section of another adjacent wound battery cell 200, and the first pole lug section of another adjacent wound battery cell 200 forms a total positive pole lug or is connected to the second pole lug section of the next adjacent wound battery cell 200. Figure 6 As shown in a), when the wound battery cells 200 are connected in parallel, the parallel wound battery cells 200 are arranged in sequence along the stacking direction of the straight portion 210 to form a rectangular module, the first pole lug portion and the second pole lug portion are located on the same side of the rectangular module, and the first pole lug portion and the second pole lug portion of two adjacent wound battery cells 200 are in the same position, all the first pole lug portions are electrically connected, and all the second pole lug portions are electrically connected.

[0050] Reference Figure 3 As shown, in some specific embodiments of the present invention, an arc portion 220 is provided with a pole lug portion 222, the pole lug portion 222 is a first pole lug portion, and the straight portion 210 is provided with a second pole lug portion extending axially along the arc portion 220, the polarity of the first pole lug portion is opposite to that of the second pole lug portion, and the first pole lug portion of a wound battery cell 200 is electrically connected to the first pole lug portion or the second pole lug portion of at least one of the remaining wound battery cells 200.

[0051] Specifically, when the first tab section of a wound cell 200 is connected to the second tab section of another wound cell 200, the wound cells 200 are connected in series, and at this time, the plurality of wound cells 200 are electrically connected in sequence through the first tab section and the second tab section. When the first tab section of a wound cell 200 is connected to the first tab section of at least one wound cell 200, the plurality of wound cells 200 are connected in parallel, and the second tab section of the wound cell 200 will also be connected to the second tab section of the corresponding wound cell 200.

[0052] In this embodiment, when the wound battery cells 200 are connected in series, multiple wound battery cells 200 are connected in sequence, and the wound battery cells 200 in series are arranged in sequence along the stacking direction of the straight portion 210 to form a rectangular module, the first pole lug portion is located on the same side of the rectangular module, and the second pole lug portion is located on the other adjacent side of the rectangular module. When the first pole lug portion of the wound battery cell 200 in two adjacent wound battery cells 200 is the positive electrode, the first pole lug portion of the other wound battery cell 200 is the negative electrode, the first pole lug portion of one wound battery cell 200 is connected to the second pole lug portion of another adjacent wound battery cell 200, and the first pole lug portion of the other adjacent wound battery cell 200 forms a total positive pole lug or is connected to the second pole lug portion of the next adjacent wound battery cell 200. When the wound battery cells 200 are connected in parallel, the parallel wound battery cells 200 are arranged in sequence along the stacking direction of the straight portion 210 to form a rectangular module, the first pole lug division is located on the same side of the rectangular module, and the second pole lug division is located on the other adjacent side of the rectangular module. The polarity of the first pole lug divisions of two adjacent wound battery cells 200 is the same, all the first pole lug divisions are electrically connected, and all the second pole lug divisions are electrically connected.

[0053] Reference Figure 1 As shown, in some specific embodiments of the present invention, if part of the pole lug division 222 extends out of the outer peripheral surface of the main body division 221, along the stacking direction of the straight portion 210, the arc portion 220 also includes a pole lug space parallel to the pole lug division 222, part of the first pole lug division is located in the second pole lug space corresponding to the second pole lug division, part of the second pole lug division is located in the first pole lug space corresponding to the first pole lug division, and the first pole lug division is directly electrically connected to the second pole lug division.

[0054] It is worth understanding that the first pole lug division is directly inserted into the second pole lug space corresponding to the second pole lug division of another wound battery cell 200, making the connection between the two wound battery cells 200 more convenient, and the structure of the wound battery cell 200 is more compact, the space utilization rate is higher, and the material cost can be effectively reduced.

[0055] In this embodiment, when the pole ear section 222 extends out from the outer peripheral surface of the main body section 221 and the pole ear section 222 includes multiple blank areas, each blank area can form a pole ear, and, from the outside of the circle to the center of the circle, the lengths of the multiple pole ears extending out gradually decrease to form a stepped shape, and the stepped multiple pole ears of the first pole ear section can complement the stepped multiple pole ears of the second pole ear section to facilitate the connection between the first pole ear section and the second pole ear section.

[0056] Reference Figure 3 , Figure 4 and Figure 5As shown, in some specific embodiments of the present invention, one wound battery cell 200 or multiple wound battery cells 200 are connected in series to form a parallel group, the number of parallel groups is multiple, the parallel group includes a first total pole lug division and a second total pole lug division, all the first total pole lug divisions of the parallel group are electrically connected to each other, and all the second total pole lug divisions are electrically connected to each other, so that all parallel groups are connected in parallel.

[0057] It is worth to understand that the number of wound cells 200 in the parallel group can be one or more, which can be selected according to actual needs. Multiple wound cells 200 connected in parallel can obtain a battery with a higher current platform.

[0058] Reference Figure 4 and Figure 5 As shown, in some specific embodiments of the present invention, the multi-roll core battery further includes: a first connecting member, and all first tab sections of the parallel group are electrically connected to the first connecting member.

[0059] It is worth understanding that by connecting all the first pole lug divisions through the first connecting piece, the length requirement for the first pole lug division extending out of the outer peripheral surface of the main body division 221 is lower. During welding, the first pole lug divisions of multiple wound battery cells 200 are connected to the first connecting piece in sequence, without the need to connect the first pole lug divisions of multiple wound battery cells 200 in sequence, thereby reducing the processing difficulty.

[0060] In this embodiment, the multi-roll core battery further includes: a second connecting member, and the second tab sections of all parallel groups are electrically connected to the second connecting member.

[0061] Reference Figure 1 As shown, in some specific embodiments of the present invention, if part of the first pole lug division extends out of the outer circumference of the corresponding first main body division, the part of the first pole lug division of a wound battery cell 200 extending out of the outer circumference of the first main body division is directly electrically connected to the first pole lug division or the second pole lug division of at least one of the remaining wound battery cells 200.

[0062] It is worth understanding that the portion of the first tab portion extending out of the outer peripheral surface of the first main body portion is electrically connected, and the connection of the first tab portion is more convenient.

[0063] Specifically, the main body division 221 of the arc portion 220 corresponding to the second tab division is the second main body division, and the shape of the second tab division may include the following:

[0064] 1. When the second tab section and the second main body section together form the outer circumference of the arc portion 220 , the portion of the first tab section extending from the first main body section is directly connected to the outer circumference of the second tab section.

[0065] 2. When the second tab section extends out of the outer peripheral surface of the second main body section, the portion of the first tab section extending out of the first main body section is directly connected to the portion of the second tab section extending out of the second main body section.

[0066] Reference Figure 4 and Figure 5 As shown, in some specific embodiments of the present invention, the multi-wound battery further includes: a connector 300 , and the tab portion 222 of a wound battery cell 200 is indirectly electrically connected to the tab portion 222 of at least one of the remaining wound battery cells 200 through the connector 300 .

[0067] It is worth to understand that all the tab sections 222 can be indirectly connected via the connector 300 to reduce the difficulty of processing the electrical connection of the tab sections 222 .

[0068] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A multi-roll core battery, characterized in that: include: shell; A plurality of wound battery cells are provided in the shell and are electrically connected. The wound battery cells include a straight portion and arc portions respectively connected to opposite sides of the straight portions, wherein one of the arc portions includes a main body section and at least one tab section, the outer circumferential surface of the tab section together with the outer circumferential surface of the main body section forms the outer circumferential surface of the arc portion or a portion of the tab section extends out of the outer circumferential surface of the main body section, and the tab section of one of the wound battery cells is electrically connected to the tab section of at least one of the remaining wound battery cells.

2. The multi-roll core battery according to claim 1, characterized in that: Both of the arc portions are provided with the pole lug division, the pole lug division of one arc portion is the first pole lug division, and the pole lug division of the other arc portion is the second pole lug division, the polarity of the first pole lug division and the second pole lug division are opposite, and the first pole lug division of one of the wound battery cells is electrically connected to the first pole lug division or the second pole lug division of at least one of the remaining wound battery cells.

3. The multi-roll core battery according to claim 1, characterized in that: One of the arc portions is provided with two pole lug portions with opposite polarities, namely a first pole lug portion and a second pole lug portion. The first pole lug portion of one of the wound battery cells is electrically connected to the first pole lug portion or the second pole lug portion of at least one of the remaining wound battery cells.

4. The multi-roll core battery according to claim 1, characterized in that: A pole lug portion is provided on the arc portion, and the pole lug portion is a first pole lug portion. The straight portion is provided with a second pole lug portion extending axially along the arc portion. The polarity of the first pole lug portion is opposite to that of the second pole lug portion. The first pole lug portion of the wound battery cell is electrically connected to the first pole lug portion or the second pole lug portion of at least one of the remaining wound battery cells.

5. The multi-roll core battery according to claim 2, 3 or 4, characterized in that: The first tab portion of one of the wound battery cells is electrically connected to the second tab portion of another of the wound battery cells, so that a plurality of the wound battery cells are sequentially connected in series.

6. The multi-roll core battery according to claim 5, characterized in that: If part of the pole lug division extends out of the outer circumferential surface of the main body division, along the stacking direction of the straight portion, the arc portion also includes a pole lug space parallel to the pole lug division, part of the first pole lug division is located in the second pole lug space corresponding to the second pole lug division, part of the second pole lug division is located in the first pole lug space corresponding to the first pole lug division, and the first pole lug division is directly electrically connected to the second pole lug division.

7. The multi-roll core battery according to claim 2, 3 or 4, characterized in that: One wound battery cell or multiple wound battery cells are connected in series to form a parallel group, and the number of the parallel groups is multiple. The parallel group includes a first total pole lug division and a second total pole lug division. All of the first total pole lug divisions of the parallel group are electrically connected to each other, and all of the second total pole lug divisions are electrically connected to each other, so that all of the parallel groups are connected in parallel.

8. The multi-roll core battery according to claim 7, characterized in that: Also includes: A first connecting member, all of the first electrode tab sections of the parallel group are electrically connected to the first connecting member.

9. The multi-roll core battery according to claim 2, 3 or 4, characterized in that: If part of the first pole tab division extends out of the outer circumference of the corresponding first main body division, the part of the first pole tab division of a wound battery cell extending out of the outer circumference of the first main body division is directly electrically connected to the first pole tab division or the second pole tab division of at least one of the remaining wound battery cells.

10. The multi-roll core battery according to claim 1, characterized in that: Also includes: A connector, wherein the tab portion of one of the wound battery cells is indirectly electrically connected to the tab portion of at least one of the remaining wound battery cells through the connector.

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