Cells, battery packs and electronic devices

Abstract

The present invention discloses a battery cell, a battery pack and an electric device. The battery cell includes an electrode assembly, a shell and a first conductive member. The electrode assembly is contained in the shell. The electrode assembly includes a first pole piece and a second pole piece. A diaphragm is provided between the first pole piece and the second pole piece. The first pole piece, the diaphragm and the second pole piece are wound to form a winding structure. Along the winding direction of the electrode assembly, the first pole piece includes a winding start end and a winding end end. The first end of the first conductive member is electrically connected to the winding start end of the first pole piece, and the second end of the first conductive member is electrically connected to the winding end end of the first pole piece. In this way, the transmission path of electrons on the first pole piece and the second pole piece can be shortened, which is conducive to reducing the internal resistance of the battery cell.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of batteries, and specifically to a battery cell, a battery pack, and an electronic device. Background Art

[0002] With the rapid development of electric vehicles and mobile electronic devices, people are paying more and more attention to and requiring higher standards for battery safety. People hope that there will be no potential safety hazards during normal use, and that the battery will not burn or explode even after being severely impacted, punctured, or otherwise damaged. As we all know, temperature rise during battery charging or discharging is a common phenomenon in the use of batteries, and excessive temperature rise will lead to excessive energy being wasted. Generally speaking, the degree of battery temperature rise is usually related to the internal components of the battery. The greater the internal resistance, the more obvious the temperature rise. Therefore, a battery with a small internal resistance is needed. Summary of the invention

[0003] In order to solve the above technical problems, the embodiments of the present application provide a battery cell, a battery pack and an electronic device with low internal resistance.

[0004] The embodiment of the present application solves the technical problem by adopting the following technical solutions:

[0005] A battery cell comprises an electrode assembly, a shell and a first conductive member, wherein the electrode assembly comprises a first pole piece and a second pole piece, a diaphragm is provided between the first pole piece and the second pole piece, the first pole piece, the diaphragm and the second pole piece are wound to form a winding structure, and along the winding direction of the electrode assembly, the first pole piece comprises a winding starting end and a winding ending end, the first end of the first conductive member is connected to the winding starting end of the first pole piece, and the second end of the first conductive member is connected to the winding ending end of the first pole piece.

[0006] In this way, by connecting the two ends of the wound first pole piece through the first conductive member, the path of electron movement can be shortened and the internal resistance of the battery cell can be reduced.

[0007] Optionally, the first conductive member further includes a first middle section, which connects the first end of the first conductive member and the second end of the first conductive member, the first end of the first conductive member is arranged at the winding starting end of the first pole piece, and the second end of the first conductive member is arranged at the winding ending end of the first pole piece; the first middle section is arranged at the end of the winding structure.

[0008] Optionally, the first conductive member includes a first conductive layer and a first insulating layer arranged on the first surface of the first conductive layer; the first end of the first conductive layer is connected to the starting end of the winding of the first pole piece, and the second end of the first conductive layer extends out of the winding structure and then bends and is connected to the winding end of the first pole piece; the first insulating layer wraps the winding structure so that one end of the first insulating layer is connected to the starting end of the winding of the first pole piece, and the other end of the first insulating layer is connected to the winding end of the first pole piece.

[0009] In this way, while the first insulating layer prevents the first pole piece from being conductively connected to the second pole piece, the two ends of the first conductive layer connect the winding starting end and the winding ending end of the first pole piece, so that electrons do not need to move from the winding ending end along the winding direction to the winding starting end, but can directly move to the winding starting end through the bridge of the first conductive layer, thereby shortening the time required for movement.

[0010] Optionally, the first conductive member further includes a second insulating layer, and the second insulating layer is disposed on a second surface of the first conductive layer, and the second surface is disposed opposite to the first surface.

[0011] Optionally, the second insulating layer completely covers the second surface of the first conductive layer and extends beyond the opposite ends of the first conductive layer, or the second insulating layer includes a first insulating member and a second insulating member, the first insulating member covers and extends beyond the first end of the first conductive layer, and the second insulating member covers and extends beyond the second end of the first conductive layer.

[0012] Optionally, the battery cell further includes a first pole lug, a first end of the first pole lug is connected to the first pole sheet, and a second end of the first pole lug extends out of the winding structure.

[0013] Optionally, the battery cell further includes a second conductive member, a first end of the second conductive member is connected to a winding start end of the second pole piece, and a second end of the second conductive member is connected to a winding end end of the second pole piece.

[0014] Optionally, the second conductive member further includes a second middle section, which connects the first end of the second conductive member and the second end of the second conductive member, the first end of the second conductive member is arranged at the winding starting end of the second pole piece, and the second end of the second conductive member is arranged at the winding ending end of the second pole piece; the second middle section is arranged at the end of the winding structure.

[0015] Optionally, the second conductive member includes a second conductive layer and a third insulating layer disposed on a surface of the second conductive layer;

[0016] The first end of the second conductive layer is connected to the winding start end of the second pole piece, and the second end of the second conductive layer extends out of the winding structure, is bent, and is connected to the winding end end of the second pole piece;

[0017] The third insulating layer wraps the winding structure so that a first end of the third insulating layer is connected to a winding start end of the second pole piece, and a second end of the third insulating layer is connected to a winding end end of the second pole piece.

[0018] Optionally, the second conductive member further includes a fourth insulating layer, wherein the fourth insulating layer is disposed on the second surface of the second conductive layer, and the second surface of the second conductive layer is disposed opposite to the first surface of the second conductive layer.

[0019] Optionally, the fourth insulating layer completely covers the other surface of the second conductive layer and extends beyond the opposite ends of the second conductive layer, or the fourth insulating layer includes a third insulating member and a fourth insulating member, the third insulating member covers and extends beyond the first end of the second conductive layer, and the fourth insulating member covers and extends beyond the second end of the second conductive layer.

[0020] Optionally, the battery cell further includes a second pole lug, a first end of the second pole lug is connected to the second pole sheet, and a second end of the second pole lug extends out of the winding structure.

[0021] The embodiment of the present application also adopts the following technical solutions to solve its technical problems:

[0022] A battery pack comprises the battery cell as described above.

[0023] The embodiment of the present application also adopts the following technical solutions to solve its technical problems:

[0024] An electronic device comprises the above-mentioned battery pack.

[0025] The beneficial effects of the embodiments of the present application are as follows: the battery cell provided by the embodiments of the present application includes an electrode assembly, a shell and a first conductive member, the electrode assembly is accommodated in the shell, the electrode assembly includes a first pole piece and a second pole piece, a diaphragm is provided between the first pole piece and the second pole piece, the first pole piece, the diaphragm and the second pole piece are wound to form a winding structure, along the winding direction of the electrode assembly, the first pole piece includes a winding start end and a winding end end; the first end of the first conductive member is electrically connected to the winding start end of the first pole piece, and the second end of the first conductive member is electrically connected to the winding end end of the first pole piece. In this way, the transmission path of electrons on the first pole piece and the second pole piece can be shortened, which is beneficial to reducing the internal resistance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0027] Figure 1 It is a schematic diagram of the structure of a battery cell in one embodiment of the present invention;

[0028] Figure 2 yes Figure 1 Schematic diagram of the internal structure of the battery cell;

[0029] Figure 3 yes Figure 2 Schematic diagram of the expansion of the first pole piece;

[0030] Figure 4 yes Figure 3 Side view of

[0031] Figure 5 yes Figure 2 A schematic diagram of a first conductive member;

[0032] Figure 6 yes Figure 5 Side view of

[0033] Figure 7 yes Figure 5 Another side view of;

[0034] Figure 8 yes Figure 2 is a cross-sectional view of a connection position between the first conductive member and the winding structure;

[0035] Fig. 9 yes Figure 8 A schematic structural diagram of the first conductive member in the installation state;

[0036] Fig.10 It is a schematic diagram of the internal structure of a battery cell according to another embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to facilitate the understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on another element or there can be one or more centered elements therebetween. When an element is described as "connected" to another element, it can be directly connected to another element or there can be one or more centered elements therebetween. The orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "vertical", "horizontal", etc. used in this specification is based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present application 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 to the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0038] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0039] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other. Figure 1 and Figure 2As shown, the battery cell 100 provided in the embodiment of the present application includes an electrode assembly 10, a shell 20 for accommodating the electrode assembly 10, and a pole ear 30, and the pole ear 30 is connected to the electrode assembly 20. Among them, the electrode assembly 10 includes a first pole piece 11, a second pole piece 12 and a diaphragm 13, and the diaphragm 13 is arranged between the first pole piece 11 and the second pole piece 12 to prevent the first pole piece 11 and the second pole piece 12 from being electrically connected to each other. The first pole piece 11, the diaphragm 13 and the second pole piece 12 are stacked on each other and wound in one direction to form a winding structure 10'. As shown in the figure, the diaphragm 13 is attached to the two opposite surfaces of the first pole piece 11, and the same is true for the second pole piece 12. The winding structure 10' includes a plurality of flat portions 11' and a plurality of curved portions 12', and each of the two ends of the curved portion 12' is connected to a flat portion 11' respectively. The flat portion 11' refers to the portion that extends straight after the first pole piece 11, the second pole piece 12 and the diaphragm 13 are wound, and the bent portion 12' refers to the portion that extends bent after the first pole piece 11, the second pole piece 12 and the diaphragm 13 are wound. The pole tab 30 is connected to the flat portion 11' of the first pole piece 11 or the second pole piece 12 after winding, and one end of the pole tab 30 extends into the winding structure 10', and the other end is arranged outside the winding structure 10'.

[0040] Please combine Figure 3 and Figure 4 For the first pole piece 11, it is a flat sheet structure as a whole, approximately in the shape of a cuboid. It includes a current collector 111, and the current collector 111 includes a long side 1111, a wide side 1112, and a thickness side 1113. The long side 1111 and the wide side 1112 together define a main surface 1113, and a rear surface 1114 arranged opposite to the main surface 1113. The main surface 1113 and the rear surface 1114 are the two surfaces with the largest area of ​​the current collector 111.

[0041] In some embodiments, the first electrode sheet 11 further includes an electrode active material layer 112, and the main surface 1113 and the rear surface 1114 are both provided with the electrode active material layer, so that the current collector 111 and the electrode active material layer 112 together constitute a complete first electrode sheet. It is worth mentioning that the first electrode sheet 11 can be a positive electrode sheet or a negative electrode sheet, and the material of the electrode active material layer 112 is different depending on the positive electrode sheet or the negative electrode sheet. Of course, if the first electrode sheet 11 is a positive electrode sheet, the second electrode sheet 12 is a negative electrode sheet, and vice versa.

[0042] Optionally, the main surface 1113 and the rear surface 1114 may be coated with the electrode active material layer 112 over the entire area. Alternatively, only a portion of the main surface 1113 and the rear surface 1114 may be coated with the electrode active material layer 112. In this case, blank areas are formed where the electrode active material layer 112 is not provided on the main surface 1113 and the rear surface 1114. It is understandable that when the pole tab 30 is connected to the first pole sheet 11, it may be connected to an area with an electrode active material 112, or it may be connected to a blank area of ​​the current collector 111, which may be specifically set according to user needs. In this embodiment, the electrode active material layer 112 is not coated on both ends of the current collector 111, and the pole tab 30 is connected to the end of the current collector 111. When the electrode assembly 10 is wound into a winding structure 10', the electrode ear 30 is located in the center of the winding structure 10', that is, the electrode assembly 10 is wound along the direction in which the long side 1111 extends, and the direction in which the long side 1111 extends is the winding direction. At this time, the end where the first pole piece 11 starts to be wound is the winding starting end 1101, and the end where the first pole piece 11 ends to be wound is the winding ending end 1102.

[0043] It is understandable that after the first pole piece 11 is wound, part of the area is in a bent state and part is still in a straight state. The bent part forms the curved portion 12' of the wound structure 10', and the straight part forms the flat portion 11' of the wound structure 10'.

[0044] The second pole piece 12 has the same structure as the first pole piece 11 , and will not be described in detail here.

[0045] Please refer again Figure 1 The pole lug 30 includes a first pole lug 31 and a second pole lug 32. The first pole lug 31 is connected to the first pole sheet 11, and the second pole lug 32 is connected to the second pole sheet 12. Specifically, the first end of the first pole lug 31 extends into the main surface 1113 and is connected to the current collector 111, and the second end of the first pole lug 31 extends out of the current collector 111 along the direction of the wide side 1112. Similarly, the second pole lug 32 is also arranged on the second pole sheet 12.

[0046] It should be understood that since the polarities of the connected first pole piece 11 and the second pole piece 12 are different, the first pole ear 31 and the second pole ear 32 also have different polarities. For example, if the first pole piece 11 is a positive pole piece, the first pole ear 31 is the positive pole ear of the battery cell 100, and if the second pole piece 12 is a negative pole piece, the second pole ear 32 should be the negative pole ear of the battery cell 100.

[0047] like Figure 5As shown, in some embodiments, the battery cell 100 further includes a first conductive member 40, the first conductive member 40 includes a first end, a second end and a first middle section, and the two ends of the first middle section are respectively connected to the first end and the second end. The first conductive member 40 is used to connect the winding start end 1101 and the winding end end 1102 of the first pole piece 11 in the winding structure 10', thereby shortening the electron transmission path and effectively reducing the internal resistance of the battery cell 100.

[0048] like Figure 6 As shown, the first conductive member 40 includes a first insulating layer 41, a first conductive layer 42 and a second insulating layer 43, wherein the first surface of the first conductive layer 42 abuts against a surface of the first insulating layer 41, and the second surface of the first conductive layer 42 abuts against a surface of the second insulating layer 43, that is, the two opposite surfaces of the first insulating layer 42 abut against a surface of the first insulating layer 41 and the second insulating layer 43, that is, the first insulating layer 41, the first conductive layer 42 and the second insulating layer 43 are stacked in sequence to form the first conductive member 40. The first conductive layer 42 has two conductive portions 421 and a middle portion 422, and the two ends of the middle portion 422 are respectively connected to the two conductive portions 421. The first insulating layer 41 covers the area of ​​the middle portion of the first surface of the first conductive layer 42, so that only the conductive portions 421 at the two ends of the first conductive layer 42 exceed the first insulating layer 41. The second insulating layer 43 covers the entire area or a portion of the second surface of the first conductive layer 42, and both ends of the second insulating layer 42 need to extend beyond the conductive portion 421 of the first conductive layer 42 to insulate the area of ​​the second surface of the first conductive layer 42 at the conductive portion 421. If the second insulating layer 43 only covers a portion of the first conductive layer 42, the second insulating layer 43 is discontinuous. Figure 7 As shown, the second insulating layer 43 is composed of two insulating parts, namely a first insulating part 431 and a second insulating part 432. The first insulating part 431 is arranged at the first end of the first conductive layer 42 and is partially exposed, and the second insulating part 432 is arranged at the second end of the second conductive layer 42 and is partially exposed.

[0049] Please combine Figure 2 and Figure 8As shown, when the first conductive member 40 is connected to the winding start end 1101 and the winding end 1102 of the first pole piece 11, that is, at this time, the first end of the first conductive member 40 is connected to the winding start end 1101, and the second end of the first conductive member 40 is bent after extending out of the winding structure 10' and connected to the winding end 1102, so that the first middle section of the first conductive member 40 spans close to or fits the end of the winding structure 10'. Among them, the first end of the first insulating layer 41 is connected to the winding start end 1101 of the first pole piece 11 after winding, the second end of the second insulating layer 42 extends out of the winding structure 10' and is connected to the winding end 1102, the middle section of the first insulating layer 42 covers the end of the winding structure 10', and the conductive portion 421 of the first conductive layer 42 is electrically connected to the winding start end 1101 and the winding end 1102 respectively. In this embodiment, the two ends of the first conductive member 40 are respectively connected to the flat portion 11' of the first pole piece 11. It should be understood that the middle section of the first conductive member 40 may be closely attached to the end of the winding structure 10 ′, or there may be a small gap between the middle section of the first conductive member 40 and the end of the winding structure 10 ′.

[0050] In some embodiments, when the first conductive member 40 is installed on the winding structure 10', the structural dimensions of the first conductive member 40 are designed as follows: Fig. 9 As shown, the length of the first insulating layer 41 on the first pole piece 11 is d1, the thickness of the first conductive layer 42 is d1, the dimension of the second insulating layer 43 beyond the end of the first conductive layer 42 is L1, the effective length of the second conductive layer 42 in contact with the first pole piece 11 is L2, and the length of the second insulating layer 43 on the first pole piece 11 is L0. Among them, the size of L1 is greater than the size of d1, the size of L2 is greater than or equal to 10mm, the size of L0 is greater than or equal to 20mm, and the effective contact area between the first conductive layer 42 and the first pole piece 11 is greater than or equal to 100m 2 .

[0051] Even though the specific structural dimensions of the first conductive member 40 when installed in the winding structure 10 ′ are limited in the above embodiment, the dimension relationship between the first conductive member 40 and the winding structure 10 ′ should not be limited thereto.

[0052] It is understandable that in order to better fix the first conductive member 40 to the winding structure 10', the second insulating layer 43 is made of an adhesive material. In this case, the second insulating layer 43 is an adhesive layer, and both ends of the adhesive layer expose the ends of the first conductive layer 42, so that the first conductive member 40 can be adhered to the winding structure 10' through the adhesive layer to achieve rapid installation. It is worth mentioning that the length of the adhesive layer can be adaptively extended until it can cover the first pole ear 31, thereby protecting the first pole ear 31. Of course, the adhesive layer can be continuous or discontinuous. When the adhesive layer is discontinuous, the middle section of the adhesive layer is disconnected, that is, only the end portion is retained. In this case, the adhesive layer includes a first adhesive member and a second adhesive member. The first adhesive member covers the first end of the first conductive layer 42 connected to the winding start end 1101 of the first pole piece 11, and the second adhesive member covers the second end of the first conductive layer 42 electrically connected to the winding end end 1102 of the first pole piece 11.

[0053] In this way, the first conductive member 40 can quickly connect the winding starting end 1101 and the winding ending end 1102 of the first electrode 11 through the adhesive layer, so that the first conductive layer 42 connects the winding starting end 1101 and the winding ending end 1102, shortening the transmission path of electrons and thereby reducing the internal resistance of the battery cell 100.

[0054] See also Fig.10 In some embodiments, the battery cell 100 further includes a second conductive member 50, the second conductive member 50 includes a first end, a second end, and a second middle section, and the two ends of the second middle section are respectively connected to the first end and the second end. The second conductive member 50 is used to connect the winding start end of the second pole piece 12 in the winding structure 10' and the winding end end of the second pole piece 12, thereby further shortening the electron transmission path and effectively reducing the internal resistance of the battery cell 100.

[0055] The internal structure of the second conductive member 50 is the same as that of the first conductive member 40, that is, the second conductive member 50 includes a third insulating layer (not shown), a second conductive layer (not shown) and a fourth insulating layer (not shown), the third insulating layer covers the first surface of the second conductive layer, and the fourth insulating layer covers the second surface of the second conductive layer. The third insulating layer is the same as the first insulating layer, the second conductive layer is the same as the first conductive layer, and the fourth insulating layer is the same as the second insulating layer. Specifically, the first end of the second conductive layer is electrically connected to the winding start end of the second pole piece 12, the second end of the second conductive layer extends out of the winding structure and then bends and is electrically connected to the winding end end of the second pole piece 12; the third insulating layer wraps the winding structure 10', and the first end of the third insulating layer is connected to the winding start end of the second pole piece 12, the second end of the third insulating layer is connected to the winding end end of the second pole piece 12, and the middle section of the third insulating layer covers the winding structure 10'.

[0056] Similarly, the fourth insulating layer can be continuous; it can also be discontinuous, that is, the fourth insulating layer includes a third insulating member and a fourth insulating member, the third insulating member covers and extends beyond the second conductive layer for electrically connecting the first end with the winding starting end of the second pole piece 12, and the fourth insulating member covers and extends beyond the second conductive layer for electrically connecting the second end with the winding ending end of the second pole piece 12.

[0057] In this way, by providing the first conductive member 40 and the second conductive member 50 , the path for electrons to move on the electrode piece can be shortened, thereby reducing the internal resistance of the wire.

[0058] It should be understood that the connection between the first conductive member and the winding starting end or the winding ending end of the first pole piece, the connection between the second conductive member and the winding starting end or the winding ending end of the second pole piece described above, etc., should be understood as including direct contact connection or indirect contact connection. Indirect contact connection means connection through other materials, such as conductive glue, etc.

[0059] Another embodiment of the present application provides a battery pack (not shown), including the battery cell 100 in the above embodiment, wherein there are multiple battery cells 100, and the multiple battery cells 100 are stacked on each other. In this way, since the internal resistance of the multiple battery cells 100 is reduced, the temperature rise of the battery pack during charging can be effectively improved.

[0060] Another embodiment of the present application provides an electronic device, comprising the battery pack of the above embodiment. For example, the electronic device may be a car or a mobile phone.

[0061] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A battery cell, comprising an electrode assembly and a shell for accommodating the electrode assembly, wherein the electrode assembly comprises a first pole piece and a second pole piece, a diaphragm is provided between the first pole piece and the second pole piece, and the first pole piece, the diaphragm and the second pole piece are wound to form a winding structure, characterized in that: Along the winding direction of the electrode assembly, the first pole piece includes a winding start end and a winding end end; The battery cell also includes a first conductive member, a first end of the first conductive member is connected to the winding starting end of the first pole piece, and a second end of the first conductive member is connected to the winding ending end of the first pole piece, wherein the first conductive member includes a first middle section, the first middle section connects the first end of the first conductive member and the second end of the first conductive member, and the first middle section is arranged at the end of the winding structure.

2. The battery cell according to claim 1, characterized in that: The first conductive member includes a first conductive layer and a first insulating layer disposed on a first surface of the first conductive layer; The first end of the first conductive layer is connected to the winding start end of the first pole piece, and the second end of the first conductive layer extends out of the winding structure, is bent, and is connected to the winding end end of the first pole piece; The first insulating layer wraps the winding structure so that one end of the first insulating layer is connected to the winding start end of the first pole piece, and the other end of the first insulating layer is connected to the winding end end of the first pole piece.

3. The battery cell according to claim 2, characterized in that: The first conductive member further includes a second insulating layer, which is disposed on a second surface of the first conductive layer, and the second surface of the first conductive layer is disposed opposite to the first surface of the first conductive layer.

4. The battery cell according to claim 3, characterized in that: The second insulating layer completely covers the second surface of the first conductive layer and extends beyond the opposite ends of the first conductive layer. or, The second insulating layer includes a first insulating member and a second insulating member, the first insulating member covers and exceeds a first end of the first conductive layer, and the second insulating member covers and exceeds a second end of the first conductive layer.

5. The battery cell according to any one of claims 1 to 4, characterized in that: It also includes a first pole lug, wherein a first end of the first pole lug is connected to the first pole piece, and a second end of the first pole lug extends out of the winding structure.

6. The battery cell according to claim 1, characterized in that: The battery cell further includes a second conductive member, a first end of the second conductive member is connected to a winding start end of the second pole piece, and a second end of the second conductive member is connected to a winding end end of the second pole piece.

7. The battery cell according to claim 6, characterized in that: The second conductive member also includes a second middle section, which connects the first end of the second conductive member and the second end of the second conductive member. The first end of the second conductive member is arranged at the starting end of the winding of the second pole piece, and the second end of the second conductive member is arranged at the ending end of the winding of the second pole piece; the second middle section is arranged at the end of the winding structure.

8. The battery cell according to claim 6, characterized in that: The second conductive member includes a second conductive layer and a third insulating layer disposed on a surface of the second conductive layer; The first end of the second conductive layer is connected to the winding start end of the second pole piece, and the second end of the second conductive layer extends out of the winding structure, is bent, and is connected to the winding end end of the second pole piece; The third insulating layer wraps the winding structure so that a first end of the third insulating layer is connected to a winding start end of the second pole piece, and a second end of the third insulating layer is connected to a winding end end of the second pole piece.

9. The battery cell according to claim 8, characterized in that: The second conductive member further includes a fourth insulating layer, wherein the fourth insulating layer is disposed on a second surface of the second conductive layer, and the second surface of the second conductive layer is disposed opposite to the first surface of the second conductive layer.

10. The battery cell according to claim 9, characterized in that: The fourth insulating layer completely covers the other surface of the second conductive layer and extends beyond the opposite ends of the second conductive layer. or, The fourth insulating layer includes a third insulating member and a fourth insulating member, the third insulating member covers and exceeds the first end of the second conductive layer, and the fourth insulating member covers and exceeds the second end of the second conductive layer.

11. The battery cell according to any one of claims 6 to 10, characterized in that: It also includes a second pole lug, a first end of the second pole lug is connected to the second pole piece, and a second end of the second pole lug extends out of the winding structure.

12. A battery pack, characterized in that: Comprising a battery cell as described in any one of claims 1 to 11.

13. An electronic device, characterized in that: Comprising the battery pack as claimed in claim 12.

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