Electrochemical device and electric device

Abstract

The invention relates to the technical field of electrochemical devices, and discloses an electrochemical device and a power utilization device, and the electrochemical device comprises a shell, an electrode assembly, an electric connecting piece and a first conductive piece. The shell comprises a bottom shell and a shell cover, a containing cavity is defined by the bottom shell and the shell cover, and a through hole communicated with the containing cavity is formed in the shell cover. The electrode assembly is contained in the containing cavity. The electric connector is arranged in the through hole through the insulating layer. The first conductive part comprises a first conductive section which is electrically connected with the electrode assembly and extends out of the electrode assembly, a second conductive section which is bent towards the direction close to the electrode assembly relative to the first conductive section, and a third conductive section which is bent towards the direction away from the electrode assembly relative to the second conductive section and is electrically connected with the electric connecting part; the second conductive section is partially separated from the third conductive section. Through the mode, the electrochemical device provided by the embodiment of the invention can improve the condition that the tab is easy to break when the electrochemical device falls off, so that the service life of the electrochemical device is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of electrochemical devices, and in particular to an electrochemical device and an electrical device. Background Art

[0002] Button batteries are widely used in various microelectronic products due to their small size. In the related art, when a button battery falls, the tab is stressed and easily breaks, which in turn affects the service life of the button battery. Summary of the invention

[0003] The purpose of the present application is to provide an electrochemical device and an electrical device, aiming to improve the problem that when the electrochemical device falls, the tabs are easily broken, which affects the service life of the electrochemical device.

[0004] The present application provides an electrochemical device, including a shell, an electrode assembly, an electrical connector and a first conductive member. The shell includes a bottom shell and a shell cover, the bottom shell and the shell cover are surrounded by a cavity, and the shell cover is provided with a through hole connected to the cavity. The electrode assembly is accommodated in the cavity. The electrical connector is arranged at the through hole and is insulated from the shell. The first conductive member includes a first conductive segment electrically connected to the electrode assembly and extending outside the electrode assembly, a second conductive segment bent toward the direction close to the electrode assembly relative to the first conductive segment, and a third conductive segment bent toward the direction away from the electrode assembly relative to the second conductive segment and electrically connected to the electrical connector. When viewed along the first direction, the second conductive segment is partially separated from the third conductive segment, wherein the first direction is the direction in which the electrode assembly and the electrical connector are relatively arranged.

[0005] In some embodiments of the present application, the third conductive segment includes a first segment and a second segment, the first end of the first segment is connected to the second end of the second conductive segment through the second bend, the second end of the first segment is connected to the second segment through the third bend, and the second segment is electrically connected to the electrical connector;

[0006] When viewed along the first direction, the first end of the first segment at least partially overlaps with the second conductive segment, and the second end of the first segment is separated from a projection of the second conductive segment.

[0007] In some embodiments of the present application, the first bend is located at a first end of the second conductive segment in the second direction, and the second bend is located at a second end of the second conductive segment in the second direction opposite to the first end, wherein the second direction is perpendicular to the first direction.

[0008] In some embodiments of the present application, the distance between the first end of the first segment and the second end of the first segment is L1, and the distance between the first end of the second conductive segment and the second end of the second conductive segment is L2, wherein L1 and L2 satisfy: 0<L1<L2.

[0009] In some embodiments of the present application, L1 and L2 satisfy: 0.18×L2≤L1<0.37×L2.

[0010] In some embodiments of the present application, a virtual straight line is drawn along the first direction through the second conductive segment and the first segment, the length of a perpendicular line from the first point where the virtual straight line intersects the second conductive segment to one end of the second conductive segment along the third direction is A1, the length of a perpendicular line from the first point to the other end of the second conductive segment along the third direction is A2, the length of a perpendicular line from the second point where the virtual straight line intersects the first segment to one end of the first segment along the third direction is A3, the length of a perpendicular line from the second point to the other end of the third conductive segment along the third direction is A4, A1, A2, A3 and A4 satisfy: |A1-A2|≠|A3-A4|, wherein any two of the third direction, the second direction and the first direction are perpendicular to each other.

[0011] In some embodiments of the present application, the distance between the first end of the first segment and the second end of the first segment is L1, and the distance between the first end of the second conductive segment and the second end of the second conductive segment is L2, wherein L1 and L2 satisfy: 0<L2<L1.

[0012] In some embodiments of the present application, a surface of the second conductive segment facing the electrode assembly and a surface of the third conductive segment facing the electrical connector are both connected to the second bent portion.

[0013] In some embodiments of the present application, when viewed along the third direction, the shortest distance N1 between the second segment and the electrode assembly in the first direction H and the shortest distance N2 between the second curved portion and the electrode assembly in the first direction H satisfy: 0<N2<N1 ， Wherein, the third direction is perpendicular to the first direction.

[0014] In some embodiments of the present application, when viewed along the first direction, the shortest distance N3 between the first curved portion and the side wall of the bottom shell opposite thereto, and the shortest distance N4 between the second curved portion and the side wall of the bottom shell opposite thereto satisfy: 0<N4<N3;

[0015] In some embodiments of the present application, the second segment has a connection area connected to the electrical connector, and a projection of the connection area in the first direction at least partially overlaps with a projection of the second conductive segment in the first direction.

[0016] In some embodiments of the present application, the electrode assembly is a wound electrode assembly, and when viewed along the first direction, the second conductive segment overlaps with the winding center of the electrode assembly.

[0017] In some embodiments of the present application, the electrode assembly is a wound electrode assembly, and when viewed along the first direction, the first segment overlaps with the winding center of the electrode assembly.

[0018] In some embodiments of the present application, the electrode assembly is a wound electrode assembly, and when viewed along the first direction, the second segment overlaps with the winding center of the electrode assembly.

[0019] In some embodiments of the present application, the electrode assembly is a wound electrode assembly, and when observed along the first direction, the second conductive segment, the first segment, and the second segment all coincide with the winding center of the electrode assembly.

[0020] In some embodiments of the present application, a projection of the first conductive member in the first direction is at least partially located within a projection of the electrical connecting member in the first direction.

[0021] In some embodiments of the present application, the electrochemical device further includes a second conductive member, and the second conductive member is electrically connected to the electrode assembly and the shell in the shell, respectively.

[0022] In some embodiments of the present application, the electrical connector includes a main body and a protrusion, the main body is connected to the surface of the shell cover facing the outside through the insulating layer, and the protrusion passes through the through hole and extends into the through hole to be electrically connected to the third conductive segment.

[0023] In some embodiments of the present application, the electrochemical device further includes a first insulating member, wherein the first insulating member is attached to a surface of the third conductive segment facing the cavity.

[0024] The third conductive segment has a connection region connected to the electrical connector, and a projection of the connection region in the first direction is located within a projection of the first insulating member in the first direction.

[0025] In some embodiments of the present application, the electrochemical device further includes a second insulating member, wherein the second insulating member is coated on a surface of the first conductive member.

[0026] In some embodiments of the present application, the insulating layer is disposed around the through hole, and along the first direction, a projection of the insulating layer in the first direction is larger than a projection of the first conductive member in the first direction.

[0027] The present application also provides an electrical device, comprising the electrochemical device as described above.

[0028] The above and other features and effects of the present application will be further understood from the following description of the embodiments of the present application in conjunction with the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0030] Figure 1 A schematic structural diagram of a first electrochemical device provided in some embodiments of the present application;

[0031] Figure 2 for Figure 1 An exploded view of the structure of the electrochemical device shown in ;

[0032] Figure 3 for Figure 1 A schematic structural diagram of the electrochemical device along a second direction shown in , wherein the electrochemical device is not equipped with a shell cover;

[0033] Figure 4 for Figure 1 A schematic structural diagram of the electrochemical device shown in FIG. 1 along a first direction, which shows the arrangement positions of the insulating layer, the electrical connector and the first conductive member;

[0034] Figure 5 for Figure 4 A cross-sectional view of the electrochemical device shown in FIG. 1 along line AA;

[0035] Figure 6 for Figure 5 A partial enlarged view of the electrochemical device shown in FIG.

[0036] Figure 7 for Figure 5 A partial enlarged view of the electrochemical device at B shown in FIG.

[0037] Figure 8 for Figure 1 Another schematic structural diagram of the electrochemical device shown in along the first direction;

[0038] Fig. 9 for Figure 1 A schematic diagram of the structure of the electrochemical device shown in FIG. after being equipped with an external conductive member;

[0039] Fig.10 A schematic structural diagram of a second electrochemical device provided in some embodiments of the present application;

[0040] Fig.11 for Fig.10 A cross-sectional view of the electrochemical device shown along line BB;

[0041] Fig.12 A schematic structural diagram of a third electrochemical device provided in some embodiments of the present application;

[0042] Fig.13 for Fig.12 A cross-sectional view of the electrochemical device shown along line CC;

[0043] Fig.14 A schematic structural diagram of a fourth electrochemical device provided in some embodiments of the present application;

[0044] Fig.15 for Fig.14 A cross-sectional view of the electrochemical device shown along line DD;

[0045] Fig.16 A schematic structural diagram of a fifth electrochemical device provided in some embodiments of the present application;

[0046] Fig.17 for Fig.16 A schematic structural diagram of the electrochemical device shown in along a first direction;

[0047] Fig.18 for Fig.16 A cross-sectional view of the electrochemical device shown along line A'-A';

[0048] Fig.19 A schematic block diagram of an electrical device provided in some embodiments of the present application. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0050] The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0051] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0053] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "perpendicular" also includes not only the absolutely perpendicular situation, but also the roughly perpendicular situation conventionally recognized in engineering. For example, if the angle between two directions is 80°-90°, the two directions can be considered perpendicular; if the angle between two directions is 0°-10°, the two directions can be considered parallel.

[0054] As mentioned in the background technology, in the related art, when a button battery falls, the tab is stressed and easily breaks, which in turn affects the service life of the button battery. Specifically, in order to ensure that the tab can be stably connected to the pole on the shell cover, the tab is usually left with redundant length, but because the internal structure of the button battery is relatively compact, when the shell cover is closed on the bottom shell to encapsulate the electrode assembly, the shell cover is likely to apply force to the tab, causing the tab itself to wrinkle. When the electrochemical device falls, these wrinkles will become the stress weak area of ​​the tab, which is easy to break and affect the service life of the electrochemical device.

[0055] Therefore, this application provides an electrochemical device, please combine Figure 4 and Figure 5 See also Figure 1 or Figure 2 The example shown, Figure 1 A schematic diagram of the structure of an electrochemical device provided in an embodiment of the present application; Figure 2 for Figure 1 An exploded view of the structure of the electrochemical device shown; Figure 4 for Figure 1 The internal structure schematic diagram of the electrochemical device along the first direction H shown; Figure 5 for Figure 4 The cross-sectional view along the AA line in FIG. 1 ; the electrochemical device includes a housing 10, an electrode assembly 20, an electrical connector 40, a first conductive member 50, and a second conductive member 60. The housing 10 is provided with a cavity 10a and a through hole 10b for connecting the cavity 10a with the external environment. The electrical connector 40 is provided on a surface 41b of the shell cover 11 of the housing 10 that is opposite to the electrode assembly 20 in the first direction H. The electrode assembly 20 is accommodated in the cavity 10a, the first conductive member 50 is respectively connected to the electrical connector 40 and one polarity pole piece of the electrode assembly 20, and the second conductive member 60 is respectively connected to the housing 10 and another polarity pole piece of the electrode assembly 20, so that the electrical connector 40 and the housing 10 both become connection terminals for connecting the electrochemical device with external devices such as an electrical device or a power supply device. In addition, the electrochemical device also includes an electrolyte accommodated in the cavity 10a, and the electrode assembly 20 can be immersed in the electrolyte. It is understandable that the shell 10 may not serve as a connection terminal of the electrochemical device. For example, in some other embodiments of the present application, the second conductive member 60 may directly extend out of the shell 10 to form a connection terminal connected to the aforementioned external device; or an additional electrical connector 40 may be added to the shell 10 to be electrically connected to the second conductive member 60 to form a connection terminal connected to the aforementioned external device.

[0056] For ease of description, we use Figure 1 and Figure 2 The coordinate system in defines various directions, wherein the coordinate axis H represents the first direction, which is the direction in which the electrode assembly 20 and the electrical connector 40 are relatively arranged; the coordinate axis L represents the second direction, which is the extension direction of the first conductive member 50; and the coordinate axis W represents the third direction, and any two of the third direction W, the second direction L and the first direction H are perpendicular to each other.

[0057] Based on the above orientation definition, the specific structures of the housing 10, the electrode assembly 20, the electrical connector 40, the first conductive member 50, and the second conductive member 60 are described below in conjunction with the various embodiments illustrated in the accompanying drawings, and the nouns used below, such as "upper", "lower", "top", and "bottom" to indicate orientation or positional relationships, are all relative to the first direction H. In addition, in the absence of conflict, the technical features involved in the different embodiments of the present application described below can be combined with each other.

[0058] For housing 10, please continue to refer to Figure 2In the example shown, in some embodiments of the present application, the housing 10 includes a housing cover 11 and a bottom housing 12. The bottom housing 12 is a cavity structure with an open top, which has a bottom wall 121 that is circular when viewed along the first direction H and a side wall 122 connected to the periphery of the bottom wall 121; the housing cover 11 may be a plate-like structure, which has a circular edge 111 when viewed along the first direction H and a through hole 10b located in the middle of the housing cover 11; the housing cover 11 may be connected and fixed to the top end surface of the bottom housing side wall 122, so that the housing cover 11 and the bottom housing 12 jointly define the housing cavity 10a of the housing 10. Exemplarily, the circular edge 111 of the housing cover 11 may be connected and fixed to the top end surface of the bottom housing side wall 122 by, but not limited to, laser welding, conductive adhesive bonding, or rivet riveting. In some other embodiments of the present application, the specific position of the through hole 10b is not limited to being located in the middle of the shell cover 11, and can also be opened on the circular edge of the shell cover 11 according to actual use requirements, or the through hole 10b can also be opened on the bottom shell 12. In addition, the embodiment of the present application does not specifically limit the shape of the shell 10, and the shape of the shell 10 can be adaptively adjusted according to actual use requirements. For example, the shape of the shell 10 can be a cuboid, an elliptical column, a prism, etc.

[0059] Exemplarily, the housing 10 may be made of a metal material resistant to electrolyte corrosion, such as steel alloy, iron alloy, iron-carbon alloy, etc., thereby reducing the situation where the electrolyte in the cavity 10a corrodes the housing 10 for a long time and leaks to the outside. It is understandable that the housing 10 is not limited to being made of the above-mentioned metal material resistant to electrolyte corrosion. For example, in some other embodiments of the present application, the housing 10 is still used as a connection terminal of the electrochemical device, then one of the shell cover 11 and the bottom shell 12 can still be made of a metal material resistant to electrolyte corrosion, such as steel alloy, iron alloy, iron-carbon alloy, etc., to be electrically connected to the second conductive member 60; the other can be made of non-metallic materials such as plastics or ceramics resistant to electrolyte corrosion. For another example, in some other embodiments of the present application, the housing 10 may not be used as a connection terminal of the electrochemical device, then the housing 10 can be made of non-metallic materials such as plastics or ceramics resistant to electrolyte corrosion.

[0060] For the electrode assembly 20, please combine Figure 5 and Figure 7 See also Figure 2 The example shown, Figure 7 for Figure 5A partial enlarged view of the B in the figure; In some embodiments of the present application, the electrode assembly 20 includes a first pole piece 21 and a second pole piece 23 with different polarities, the first pole piece 21 includes a first current collector 211 and a first active material layer 212 coated on two opposite surfaces of the first current collector 211, the second pole piece 23 includes a second current collector 231 and a second active material layer 232 coated on two opposite surfaces of the second current collector 231, and a separator 22 is sandwiched between a first active material layer 212 and a second active material layer 232. The first pole piece 21, the separator 22 and the second pole piece 23 are sequentially stacked and wound around the winding center axis X to form a cylindrical winding structure and are accommodated in the cavity 10a of the shell 10, wherein the winding center axis X of the cylindrical winding structure roughly coincides with the central axis of the through hole 10b on the shell cover 11. It should be noted here that, since the winding center axis X of the cylindrical winding structure roughly coincides with the central axis of the through hole 10b on the shell cover 11, it means that the winding center axis X of the cylindrical winding structure can also be the first direction H of the electrochemical device. It can be understood that the specific structure of the electrode assembly 20 is actually diverse; for example, in some other embodiments of the present application, the electrode assembly 20 can be a stacked structure formed by staggering and stacking a plurality of first pole pieces 21 and a plurality of second pole pieces 23 and sandwiching a separator 22 between any two adjacent pole pieces, wherein the stacking direction of the stacked structure is roughly perpendicular to the central axis X of the through hole 10b on the shell cover 11; for another example, in some other embodiments of the present application, the electrode assembly 20 can be a winding structure formed by winding a composite pole piece, and the composite pole piece is formed by coating an active material layer formed on the basis of a composite current collector.

[0061] It can also be understood that the embodiments of the present application do not specifically limit the polarity of the electrical connector 40 and the housing 10. For example, in some embodiments of the present application, the first electrode 21 is a positive electrode, and the electrical connector 40 can be used as the positive electrode connection terminal of the electrochemical device; the second electrode 23 is a negative electrode, and the housing 10 can be used as the negative electrode connection terminal of the electrochemical device; for another example, in some embodiments of the present application, the first electrode 21 is a negative electrode, and the electrical connector 40 can be used as the negative electrode connection terminal of the electrochemical device; the second electrode 23 is a positive electrode, and the housing 10 can be used as the positive electrode connection terminal of the electrochemical device. For the sake of simplicity, the following description takes the first pole piece 21 as the positive pole piece and the second pole piece 23 as the negative pole piece as an example, wherein the first current collector 211 may be at least one of Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W, Mo, Al, Mg, K, Na, Ca, Sr, Ba, Si, Ge, Sb, Pb, In, Zn and combinations (alloys) thereof. Exemplarily, the first current collector 211 may be made of copper foil. The first active material layer 212 may include, but is not limited to, lithium metal oxides such as LiNi1 / 3Mn1 / 3Co1 / 3O2, LiCoO2, LiNiO2, LiMn2O4, LiCoMnO4, Li2NiMn3O8. Alternatively, lithium metal phosphates such as LiFePO4, LiMnPO4, LiNiPO4, LiCoPO4, Li3Fe2(PO4)3 and Li3V2(PO4)3. Continue as Figure 5 As shown, in some embodiments of the present application, the empty foil area of ​​the first current collector 211 at the outermost circle of the cylindrical winding structure is electrically connected to the first conductive member 50. The following is an example of the second pole piece 23 as a negative pole piece, wherein the second current collector 231 may be at least one of Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W, Mo, Al, Mg, K, Na, Ca, Sr, Ba, Si, Ge, Sb, Pb, In, Zn and combinations (alloys) thereof. Exemplarily, the second current collector 231 may be made of aluminum foil. The second active material layer 232 may include, but is not limited to, carbon materials such as graphite and hard carbon, or Si, Si alloys and Li4Ti5O 12 etc. Continue as Figure 5 As shown, in some embodiments of the present application, the empty foil area of ​​the second current collector 231 at the outermost circle of the cylindrical winding structure is electrically connected to the second conductive member 60. It can still be understood that the first conductive member 50 is not only connected to the first current collector 211 at the outermost circle of the cylindrical winding structure. For example, in some embodiments, it is not limited to only Fig.18As shown, the first conductive member 50 is connected to the first current collector of the cylindrical winding structure near the winding center X, that is, the first conductive member 50 can be connected to the portion of the first current collector 211 that is closer to the winding center axis X than the portion in the outermost circle of the cylindrical winding structure. Similarly, whether the second conductive member 60 is connected to the second current collector 231 of the outermost circle of the cylindrical winding structure is not specifically limited here, and the second conductive member 50 can also be connected to the portion of the second current collector 231 that is closer to the winding center axis X than the portion in the outermost circle of the cylindrical winding structure.

[0062] For electrical connector 40, continue to combine Figure 2 See also Figure 5 In the example shown, in some embodiments of the present application, the electrical connector 40 includes a main body 41 and a protrusion 42. The main body 41 has a first surface 41a and a second surface 41b disposed opposite to each other along a first direction H, the first surface 41a is electrically connected to the first conductive member 50, and the second surface 41b is connected and fixed to the shell cover 11 through the insulating layer 30. Exemplarily, the insulating layer 30 is an insulating sealant, and the insulating sealant is disposed around the protrusion 42, so that the second surface 41b of the main body can be bonded and fixed to the surface of the shell cover 11 facing the cavity 10a by the insulating sealant, thereby the electrical connector 40, the insulating layer 30 and the shell 10 can jointly seal the cavity 10a of the shell 10. The protrusion 42 is integrally connected to the second surface 41b, and the protrusion 42 can pass through the through hole 10b on the shell cover 11 and extend out of the through hole 10b, and the end surface of the protrusion 42 extending out of the through hole 10b is used to be electrically connected to the external conductive member 2. Exemplarily, as Fig. 9 As shown, in other embodiments of the present application, an external conductive member 22 may be welded and fixed to the first surface 41a of the main body, and the surface of the external conductive member 22 may be covered with insulating tape (not shown) so that the external conductive member 2 can fit the outer surface of the shell cover 11 and bend and extend to the outer peripheral wall of the bottom shell 12, so that the electrochemical device and the external conductive member 2 together form a battery packaging structure, thereby saving the occupied space of the battery packaging structure as much as possible.

[0063] It is understandable that the electrical connector 40 is not limited to being connected and fixed to the housing cover 11 in the above-mentioned form. Fig.10 and Fig.11In the example shown, in some other embodiments of the present application, the first surface 41a of the main body can be used to electrically connect with the external conductive member 22, and the second surface 41b of the main body is connected and fixed with the shell cover 11 through the insulating layer 30. For example, the insulating layer 30 is an insulating sealant, and the insulating sealant is arranged around the convex portion 42, so that the second surface 41b of the main body 41 can be bonded and fixed to the surface of the shell cover 11 facing the outside through the insulating sealant, thereby the electrical connector 40, the insulating layer 30 and the shell 10 can jointly seal the cavity 10a of the shell 10. The convex portion 42 is integrally connected to the second surface 41b, and the convex portion 42 can be electrically connected to the first conductive member 50.

[0064] Alternatively, see Fig.12 and Fig.13 In the example shown, in some other embodiments of the present application, the electrical connector 40 may also be substantially in the form of a plate, and its second surface 41b may still be bonded and fixed to the surface of the shell cover 11 of the housing 10 facing the outside by, but not limited to, insulating sealant. The first surface 41a of the electrical connector is used to electrically connect to the external conductive member 2, and the area of ​​the electrical connector 40 exposed in the through hole 10b is electrically connected to the first conductive member 50.

[0065] Alternatively, see Fig.14 and Fig.15 In the example shown, in some other embodiments of the present application, the electrical connector 40 may be a substantially plate-shaped structure, and the second surface 41b of the electrical connector 40 may be bonded and fixed to the surface of the housing cover 11 facing the cavity 10a by, but not limited to, insulating sealant. The area of ​​the electrical connector 40 exposed in the through hole 10b is used for electrical connection to the external conductive member 2, and the first surface 41a of the electrical connector 40 is electrically connected to the first conductive member 50.

[0066] It should be noted here that in the above embodiments, the projected area of ​​the insulating layer 30 in the first direction H is larger than the projected area of ​​the second surface 41b of the main body 41 in the first direction H. In this way, the short circuit between the edge of the electrical connector 40 of the electrochemical device and the shell cover 11 can be improved.

[0067] In some embodiments of the present application, the electrical connector 50 may be made of at least one of Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W, Mo, Al, Mg, K, Na, Ca, Sr, Ba, Si, Ge, Sb, Pb, In, Zn and combinations (alloys) thereof. For example, the electrical connector may be made of aluminum foil.

[0068] For the first conductive member 50, please combine Figure 3 as well as Figure 6 See also Figure 4In the example shown, in some embodiments of the present application, the first conductive member 50 includes a first conductive segment 51, a second conductive segment 53 and a third conductive segment 55. The first end of the first conductive segment 51 is electrically connected to the empty foil area of ​​the first current collector 211 in the outermost circle of the cylindrical winding structure. When viewed along the second direction L, the second end of the first conductive segment 51 extends out of the top of the cylindrical winding structure along the first direction H. The first end 53a of the second conductive segment 53 is connected to the second end of the first conductive segment 51 through the first bending portion 52, wherein the second conductive segment 53 extends from the edge of the cylindrical winding structure toward the winding center X of the cylindrical winding structure, and the direction of the second conductive segment 53 from the edge of the cylindrical winding structure toward the winding center of the cylindrical winding structure is the extension direction L of the first conductive member 50. The first bending portion 52 is formed by bending the end of the first bending portion 52 connected to the second conductive segment 53 toward the direction close to the cylindrical winding structure. The third conductive segment 55 includes a first segment 551 and a second segment 553. The first end 551a of the first segment 551 is connected to the second end 53b of the second conductive segment through the second bend 54, wherein the first segment 551 extends from the center X of the cylindrical winding structure toward the edge of the cylindrical winding structure, and the second bend 54 is formed by bending the end of the second bend 54 connected to the first segment 551 away from the cylindrical winding structure. The second segment 553 is electrically connected to the end surface of the protrusion 42 of the electrical connector 40 extending into the through hole 10b, and the second segment 553 is connected to the end of the first segment 551 away from the second bend 54 through the third bend 552, wherein the third bend 552 is formed by bending the end of the third bend 552 connected to the second segment 553 away from the cylindrical winding structure. When viewed along the first direction H, the second conductive segment 53 and the third conductive segment 55 are partially separated. When viewed along the first direction H, the projection of the second conductive segment 53 and the projection of the third conductive segment 55 are separated. The extension direction of the second conductive segment 53 is different from the extension direction of the third conductive segment 55. Figure 4 , Figure 8 as well as Fig.17 As shown, the included angle α between the extension direction of the second conductive segment 53 and the extension direction of the third conductive segment 55 satisfies: 0<α≤90°.

[0069] In some embodiments of the present application, the first conductive segment 51, the second conductive segment 53 and the third conductive segment 55 of the first conductive member 50 are pre-bent and then connected and fixed to the electrode assembly 20 and the electrical connector 40 respectively. The advantage of such a setting is that not only the redundant length of the first conductive member 50 can be reduced, but also the existence of each bent portion will make the first conductive member 50 as a whole shrink, which in turn enhances the connection reliability between the shell cover 11 and the bottom shell 12, thereby extending the service life of the electrochemical device. In some embodiments of the present application, the first conductive member 50 can be made of at least one of Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W, Mo, Al, Mg, K, Na, Ca, Sr, Ba, Si, Ge, Sb, Pb, In, Zn and combinations (alloys) thereof. Exemplarily, the first conductive member 50 can be made of aluminum foil of the same material as the electrical connector 40.

[0070] In some embodiments of the present application, the projection of the first segment 551 in the first direction H is separated from the projection of the second conductive segment 53 in the first direction H. Figure 4 , Figure 8 or Fig.17As shown, the first segment 551 is connected to the second conductive segment 53 through the second bend 54, and the first segment 551 is connected to the third segment 553 through the third bend 552. The first segment 551 includes a first end 551a connected to the second bend 54 and a second end 551b connected to the third bend 552. When viewed along the first direction H, the first end 551a of the first segment 551 at least partially overlaps with the second conductive segment 53. When viewed along the first direction H, the second end 551b of the first segment 551 is separated from the projection of the second conductive segment 53. Specifically, when viewed along the first direction H, the second end 551b of the first segment 551 is separated from the projection of the second conductive segment 53. The projection of the second end 551b of the first segment 551 in the first direction H is separated from the projection of the second conductive segment 53 in the first direction H. In this way, the second conductive segment 53 and the first segment 551 have an overlapping portion, which reduces the occupied area of ​​the first conductive member 50 in the first direction H, thereby reducing the risk of short-circuiting between the second current collector 231 of the electrode assembly 20 and the first conductive member 50 when the electrochemical device is in motion. In addition, compared with the first end 551a and the second end 551b of the first segment 551 that are not separated from the second conductive segment 53, on the one hand, the first segment 551 can be fixed to the shell cover 11 and the bottom shell 12. The second conductive segment 53 is abutted against the second conductive segment 53, so that the contact portion between the second conductive segment 53 and the first segment 551 can form a force point to disperse the force occurring in the second curved portion 54, thereby improving the connection strength of the second curved portion 54; on the other hand, since the second end 551b of the first segment 551 is separated from the second conductive segment 53 along the first direction H, the first curved portion 52, the second curved portion 54 and the third curved portion 552, which have a larger spacing along the first direction H than other parts of the first conductive member 50, can be respectively arranged in different areas of the gap between the shell cover 11 and the electrode assembly 20, thereby improving the energy density of the electrochemical device. In addition, the third conductive segment 55 and the second conductive segment 53 have a separated portion in the first direction H, thereby suppressing the shortening of the life due to friction during use of the product.

[0071] Continue as Figure 4As shown, in some embodiments of the present application, the second curved portion 54 is located at the first end 5301 of the second conductive segment 53 in the second direction L, and the first curved portion 52 is located at the second end 5302 of the second conductive segment 53 in the second direction L, which is opposite to the first end 5301. Observed along the first direction H, the second conductive segment 53 extends from the edge of the cylindrical winding structure toward the winding center X of the cylindrical winding structure, and after exceeding the winding center X of the cylindrical winding structure, extends to the edge of the cylindrical winding structure on the opposite side of the connection with the first conductive segment 51. In this way, the first curved portion 52 and the second curved portion 54 are respectively located on different sides of the cylindrical winding structure, that is, there is a gap between the first curved portion 52 and the second curved portion 54 to accommodate the winding center of the electrode assembly, which can improve the situation where the material cannot be pressed and cannot be bent or the bending is severely deformed due to the small gap between the first curved portion 52 and the second curved portion 54.

[0072] Continue as Figure 4 As shown, in some embodiments of the present application, the length of the third conductive segment 55 is L1, the length of the second conductive segment 53 is L2, and L1 and L2 satisfy: 0<L1<L2. In this way, the length of the second conductive segment 53 and the first segment 551 can be increased so that there is still redundancy after the second segment 553 is connected and fixed to the protrusion 42 of the electrical connector 40, so as to cope with the errors generated by the first conductive member 50 and the electrical connector 40 during machining. In addition, since L2 is greater than L1, when the electrode assembly 20 of the electrochemical device moves, the second conductive segment 53 with a longer length can swing with a smaller amplitude as the electrode assembly moves, thereby improving the stress condition of the stress-weakened area of ​​the first bend 52, thereby improving the connection strength of the first bend 52.

[0073] In some embodiments of the present application, 0.18×L2≤L1<0.37×L2. Wherein, L1<0.18×L2 means that the first segment 551 is easy to contact with the protrusion 42 of the electrical connector and cause wear and degradation of the material, and L1>0.37×L2 means that the interval between the second curved portion 54 and the side wall 122 of the bottom shell is short and easy to contact with the side wall 122 of the bottom shell and cause wear and degradation of the material. Therefore, when L1 is within this numerical range, the second conductive segment 53 and the first conductive segment 51 can be pre-folded, and a good interval can be maintained between the second curved portion 54 and the inner peripheral wall of the bottom shell 12.

[0074] like Figure 8As shown, in some embodiments of the present application, a virtual straight line Y is drawn along the first direction H through the second conductive segment 53 and the first segment 551, the length of the perpendicular line from the point where the virtual straight line Y intersects with the second conductive segment 53 to one end of the second conductive segment 53 along the third direction W is A1, the length of the perpendicular line from the point where the virtual straight line Y intersects with the second conductive segment 53 to the other end of the second conductive segment 53 along the third direction W is A2, the length of the perpendicular line from the point where the virtual straight line Y intersects with the first segment 551 to one end of the first segment 551 along the third direction W is A3, the length of the perpendicular line from the point where the virtual straight line Y intersects with the first segment 551 to the other end of the third conductive segment 5543 along the third direction W is A4, wherein A1, A2, A3 and A4 satisfy: |A1-A2|≠|A3-A4|. This point will be explained later in conjunction with the drum drop test of the present electrochemical device.

[0075] Alternatively, see Figure 16-Figure 18 The example shown is different from the above-mentioned application embodiments in that the first conductive member 50 can extend from the portion of the cylindrical winding structure close to the winding center, and the first conductive member 50 is connected in a bending form different from the above-mentioned application embodiments. In some embodiments of the present application, 0<L2<L1. That is, there is a large gap between the third bending portion 552 and the second bending portion 54, which can improve the situation where the material cannot be pressed and cannot be bent or the bending is severely deformed due to the small gap between the third bending portion 552 and the second bending portion 54.

[0076] like Figure 6 As shown, in some embodiments of the present application, the surface of the second conductive segment 53 facing the electrode assembly 20 and the surface of the first segment 551 of the third conductive segment 55 facing the electrical connector 40 are both connected to the second bent portion 54 .

[0077] like Figure 5 As shown, in some embodiments of the present application, when viewed along the third direction W, the shortest distance N1 between the second segment 553 and the electrode assembly 20 in the first direction H and the shortest distance N2 between the second curved portion 54 and the electrode assembly 20 in the first direction H satisfy: 0<N2<N1. Such a configuration is conducive to reducing the squeezing of the second curved portion 54 on the bottom shell 12 and reducing the risk of reduced welding strength between the bottom shell 12 and the shell cover 11.

[0078] like Figure 8 As shown, in some embodiments of the present application, the shortest distance N3 between the first curved portion 52 and the side wall 122 of the bottom shell 12 opposite thereto, and the shortest distance N4 between the second curved portion 54 and the side wall 122 of the bottom shell 12 opposite thereto satisfy: 0<N3<N4. In this way, it is helpful to reduce the squeezing of the bottom shell 12 by the second curved portion 54, and reduce the risk of the welding strength between the bottom shell 12 and the shell cover 11 decreasing.

[0079] like Figure 4 As shown, in some embodiments of the present application, the second segment 553 has a connection area S connected to the electrical connector 40, and the projection of the connection area S in the first direction H at least partially overlaps with the projection of the second conductive segment 53 in the first direction H. Further, when viewed along the first direction H, the connection area S may overlap with the center X of the electrode assembly 20. This helps to reduce the stress on the second bent portion 54 and improve the service life of the electrochemical device.

[0080] In some embodiments of the present application, when viewed along the first direction H, the second conductive segment 53 overlaps with the winding center X of the electrode assembly 20, and the third conductive segment 55 may be separated from the center X of the electrode assembly 20. Such an arrangement is conducive to improving the heat dissipation effect of the second conductive segment 53 and the third conductive segment 55.

[0081] In some embodiments of the present application, when viewed along the first direction H, the first segment 551 overlaps with the center X of the electrode assembly 20, and the second conductive segment 53 may be separated from the center X of the electrode assembly 20. Such a configuration is conducive to improving the heat dissipation effect of the second conductive segment 53 and the third conductive segment 55.

[0082] In some embodiments of the present application, when observed along the first direction H, the second conductive segment 53 , the first segment 551 , and the second segment 553 all coincide with the winding center X of the electrode assembly 20 .

[0083] In consideration of improving the service life of the electrochemical device, especially after the second segment 553 is welded and fixed to the end surface of the protrusion 42 extending into the through hole 10b, the welding slag generated by welding can be reduced to fall into the electrode assembly 20 and pierce the separator 22 to cause a short circuit in the electrode assembly 20. Figure 6 As shown, in some embodiments of the present application, the surface of the second segment 553 facing the cavity 10a may be attached with a first insulating member 71. The projection of the aforementioned connection area in the first direction H is located within the projection of the first insulating member 71 in the first direction H. Therefore, on the one hand, the first insulating member 71 can prevent the welding slag generated by the welding part of the second segment 553 and the convex portion 42 of the electrical connector 40 from falling into the electrode assembly 20, and on the other hand, it can reduce the friction and wear between the third conductive segment 55 and the second segment 553 under the action of external force, so as to maintain the current carrying capacity of the first conductive member 50. Exemplarily, the first insulating member 71 is an insulating tape.

[0084] Continue as Figure 6 As shown, in some embodiments of the present application, the outer surface of each part of the first conductive member 50 is coated with a second insulating member 72, so that the first conductive member 50 is directly in contact with the shell cover 11 of the housing 10, the bottom shell 12 of the housing 10 and the second pole piece 23 of the electrode assembly 20, thereby reducing the occurrence of a short circuit inside the electrochemical device. Exemplarily, the second insulating member 72 is an insulating tape.

[0085] like Figure 4 As shown, in some embodiments of the present application, when viewed along the first direction H, a projection of the first conductive member 50 in the first direction H is at least partially located within a projection of the electrical connector 40 in the first direction H.

[0086] For the second conductive member 60, please continue to refer to Figure 5 In the example shown, in the embodiment of the present application, one end of the second conductive member 60 can be electrically connected to the empty foil area of ​​the second pole piece 23 of the outermost circle of the cylindrical winding structure, and the other end of the second conductive member 60 extends out of the bottom of the winding structure and bends and extends in the direction close to the bottom wall 121 of the bottom shell 12, and is electrically connected to the bottom wall 121 of the bottom shell 12. The welding points of the second conductive member 60 and the cylindrical winding structure and the welding points of the first conductive member 50 and the cylindrical winding structure are respectively located at the two ends of the cylindrical winding structure along the second direction L, so that the second conductive member 60 and the first conductive member 50 can jointly support the electrode assembly 20 to alleviate the pulling of the first conductive member 50 when the cylindrical winding structure moves inside the shell 10, thereby further improving the situation of breaking the circuit due to the fracture of the weak parts of the bending stress of the first conductive member 50. In some embodiments of the present application, the second conductive member 60 may be made of at least one of Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W, Mo, Al, Mg, K, Na, Ca, Sr, Ba, Si, Ge, Sb, Pb, In, Zn and combinations (alloys) thereof. For example, the second conductive member 60 may be made of copper foil.

[0087] In the examples of the present application, experiments were conducted on the same design system and the same model of electrochemical device.

[0088] Comparative Example 1

[0089] The first conductive member is directly connected and fixed to the electrode assembly and the shell cover, and then the first conductive member is not folded to fix the shell cover on the bottom shell.

[0090] In this electrochemical device, when the shell cover and the bottom shell are closed, wrinkles are generated at the bend formed by the first conductive member and the electrode assembly, which lifts up the shell cover and affects the connection quality between the shell cover and the bottom shell; secondly, when the electrochemical device is subjected to a drop drum test, the bend where the wrinkles of the first conductive member are generated is easily torn / broken during the movement and rotation of the electrode assembly, causing failure of the electrochemical device.

[0091] Comparative Example 2

[0092] The difference from comparative example 1 is that the first conductive member is pre-folded after being led out from the electrode assembly, and then the shell cover is fixed to the bottom shell. The first conductive member satisfies: L1 = 0.42 × L2, |A1-A2|≠|A3-A4|.

[0093] The problem with this electrochemical device is that L1 is relatively long, and the first conductive component occupies more space, which may easily cause electrolyte overflow after the shell cover and the bottom shell are connected, affecting the connection quality of the shell cover; secondly, the second curved portion is closer to the connection point of the shell cover, and the shell cover may be easily lifted up under the action of the shell cover, which may also affect the connection quality of the shell cover and the bottom shell.

[0094] Comparative Example 4

[0095] The difference from comparative example 1 is that the first conductive member is pre-folded after being led out from the electrode assembly, and then the shell cover is fixed to the bottom shell. The first conductive member satisfies: L1 = 0.32 × L2, |A1-A2| = |A3-A4|.

[0096] In this electrochemical device, the second conductive segment overlaps with the third conductive segment after pre-folding, and the second curved portion is short and easily wrinkled, resulting in concentrated stress. The rotation of the electrode assembly during the drum drop process can easily tear the curved portion of the first conductive member. In addition, the second curved portion is close to the connection between the shell cover and the bottom shell, which can easily lift up the shell cover during assembly, affecting the connection quality between the shell cover and the bottom shell.

[0097] Example 1

[0098] The difference from comparative example 1 is that the first conductive member is pre-folded after being led out from the electrode assembly, and then the shell cover is fixed to the bottom shell. The first conductive member satisfies: L1 = 0.18 × L2, |A1-A2|≠|A3-A4|.

[0099] The folded first conductive member in this electrochemical device forms a buffer structure, which can alleviate the pulling of the first conductive member in the axial and radial directions during the internal movement of the electrode assembly when the electrochemical device is dropped into a roller test, thereby improving the risk of open circuit / short circuit of the electrochemical device caused by tearing / breaking of the first conductive member at the bend with the electrode assembly; at the same time, |A1-A2|≠|A3-A4|, which means that the fold of the second bend is longer to disperse the stress, and the bend of the first conductive member is not easy to tear / break during the roller drop process.

[0100] Example 2

[0101] The difference from comparative example 1 is that the first conductive member is pre-folded after being led out from the electrode assembly, and then the shell cover is fixed to the bottom shell. The first conductive member satisfies: L1 = 0.37 × L2, |A1-A2|≠|A3-A4|.

[0102] The folded first conductive member in this electrochemical device forms a buffer structure, which can alleviate the pulling of the first conductive member in the axial and radial directions during the internal movement of the electrode assembly when the electrochemical device is dropped into a roller test, thereby improving the risk of the electrochemical device being broken or short-circuited due to the tearing or breaking of the first conductive member at the bend with the electrode assembly. Compared with Example 1, the second bend is farther away from the second segment of the third conductive segment, and the pulling and buffering effect of the first conductive member during the drop into the roller is better.

[0103] Example 3

[0104] The difference from comparative example 1 is that the first conductive member is pre-folded after being led out from the electrode assembly, and then the shell cover is fixed to the bottom shell. The first conductive member satisfies: L1 = 0.32 × L2, |A1-A2|≠|A3-A4|.

[0105] The folded first conductive member in the electrochemical device forms a buffer structure, which can alleviate the pulling of the first conductive member in the axial and radial directions during the internal movement of the electrode assembly when the electrochemical device is dropped into a roller test, thereby improving the risk of the electrochemical device being broken or short-circuited due to the tearing or breaking of the first conductive member at the bend with the electrode assembly. Compared with Example 1, the second bend is farther from the second segment of the third conductive segment, and the pulling and buffering effect of the first conductive member is stronger during the drop into the roller. At the same time, |A1-A2|≠|A3-A4|, and compared with Comparative Example 4, the second bend is farther from the connection between the shell cover and the bottom shell, and it is not easy to lift up the shell cover and affect the shell cover connection.

[0106] Verification test 1: The battery cell cover and the bottom shell were welded and assembled according to the scheme described in the comparative example and the embodiment, the welding yield was counted, the defective welded products were disassembled, and the position of the winding body corresponding to the welding failure position was observed. The test results are shown in Table 1.

[0107] Verification test 2: Charge the battery cell with a current of 0.18C at room temperature to the charging limit voltage, and perform a drop test with a special drop test fixture for the battery cell. Grab the sample with a robotic arm at a height of 1.8m and release it on a marble slab. Drop it 3 times in the order of shell cover facing down → shell bottom facing down → battery column facing down. After each round of drops, observe whether the battery cell is damaged or leaking, and measure the open circuit voltage of the battery cell. If the voltage is less than 3.0V, the battery cell is judged to have failed. If there is no damage or leakage, and the open circuit voltage is higher than 3.0V, it is judged to have not failed. Continue testing until failure, and record the number of drops when the battery cell fails. Then disassemble the battery cell and observe the failure mode. The test results are shown in Table 2.

[0108] Verification test 3: Charge the battery cell with a current of 0.18C at room temperature to the charging limit voltage, and perform a roller drop test using a special roller drop test fixture for the battery cell, dropping it from a height of 1m and dropping it 500 times at a speed of 5 turns / min (2 drops count as one round). After every 50 roller drops, observe whether the battery cell is damaged or leaking, and measure the open circuit voltage of the battery cell. If the voltage is less than 3.0V, the battery cell is judged to have failed. If there is no damage or leakage, and the open circuit voltage is higher than 3.0V, it is judged to have not failed. Continue testing until failure, and record the number of drops when the battery cell fails. Then disassemble the battery cell and observe the failure mode. The test results are shown in Table 3.

[0109] Table 1: Base shell / shell cover laser welding quality and failure mode

[0110]

[0111] Referring to Table 1, when L1<0.37×L2, the welding quality rate of the bottom shell / shell cover is higher; and the welding quality rate of |A1-A2|≠|A3-A4| is higher than that of |A1-A2|=|A3-A4|.

[0112] Table 2: Number of drops to failure in drop test

[0113]

[0114]

[0115] Referring to Table 2, when L1<0.18×L2, the number of drop failures is low, and the edge of the third conductive segment is prone to breakage; when |A1-A2|≠|A3-A4|, the number of drop failures is low, and the folding part of the first conductive member is prone to breakage.

[0116] Table 3: Roller drop pass rate

[0117]

[0118] Referring to Table 3, the first group of verifications shows that when L1 is less than 0.18×L2, the roller drop performance is poor; the second group of verifications shows that when |A1-A2|=|A3-A4|, the roller drop is likely to cause the bending portion of the first conductive member to break. At the same time, both groups of verifications show that if the first conductive member is not pre-folded, the roller drop pass rate of the electrochemical device is very low.

[0119] Table 4: Summary of the results of each verification item of the comparative examples and embodiments

[0120]

[0121]

[0122] See Table 4, the principle of the specific technical effect can refer to the above. According to the experimental results, the shell cover / bottom shell welding rate, drop & roller drop comprehensive effect of Examples 1-4 are obviously better than those of Comparative Examples 1-3, among which Examples 2 and Example 4 are better than other examples in the drop test.

[0123] In summary, the welding efficiency and safety of the electrochemical device provided in the embodiments of the present application can be significantly improved.

[0124] See also Fig.19 The present application also provides an electrical device, which includes the electrochemical device 1 as described above. The electrical device 1 may be a consumer electronic product, such as a smart watch, a wireless headset, or a smart phone. It is understood that in other embodiments, the electrical device may also be an electric tool, an energy storage device, a power device, etc. For example, the electrical device may also be an electric car.

[0125] The above descriptions are merely embodiments of the present application and are not intended to 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 applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An electrochemical device, characterized in that The electrochemical device is cylindrical and comprises: A shell, the shell comprising a bottom shell and a shell cover, the bottom shell and the shell cover surround a cavity, and the shell cover is provided with a through hole communicating with the cavity; An electrode assembly, wherein the electrode assembly is accommodated in the cavity; an electrical connector, the electrical connector being disposed in the through hole through an insulating layer; and A first conductive member, the first conductive member includes a first conductive segment, a second conductive segment and a third conductive segment, the first end of the first conductive segment is electrically connected to the electrode assembly, the first end of the second conductive segment is connected to the second end of the first conductive segment through a first bending portion, the third conductive segment is connected to the second end of the second conductive segment in a second direction opposite to the first end through a second bending portion, the third conductive segment is electrically connected to the electrical connector, and when viewed along the first direction, an angle between an extension direction of the second conductive segment and an extension direction of the third conductive segment is α, 0<α≤90°, wherein the first direction is a direction in which the electrode assembly and the electrical connector are relatively arranged, and the second direction is perpendicular to the first direction.

2. The electrochemical device according to claim 1, characterized in that The third conductive segment includes a first segment and a second segment, the first end of the first segment is connected to the second end of the second conductive segment through the second bend, the second end of the first segment is connected to the second segment through the third bend, and the second segment is electrically connected to the electrical connector; Observing along the first direction, the first end of the first segment at least partially overlaps with the second conductive segment, and the angle between the extension direction of the first segment and the extension direction of the second conductive segment is α, 0<α≤90°.

3. The electrochemical device according to claim 2, characterized in that The distance between the first end of the first segment and the second end of the first segment is L1, and the distance between the first end of the second conductive segment and the second end of the second conductive segment is L2, wherein L1 and L2 satisfy: 0<L1<L2.

4. The electrochemical device according to claim 3, characterized in that L1 and L2 satisfy: 0.18×L2≤L1<0.37×L2.

5. The electrochemical device according to claim 1, characterized in that The electrode assembly is a wound electrode assembly, and the first bent portion and the second bent portion are respectively located on different sides of a winding center of the electrode assembly.

6. The electrochemical device according to claim 2, characterized in that The distance between the first end of the first segment and the second end of the first segment is L1, and the distance between the first end of the second conductive segment and the second end of the second conductive segment is L2, wherein L1 and L2 satisfy: 0<L2<L1.

7. The electrochemical device according to claim 2, characterized in that The second segment has a connection area connected to the electrical connector, and a projection of the connection area in the first direction at least partially overlaps with a projection of the second conductive segment in the first direction.

8. The electrochemical device according to claim 7, characterized in that The electrode assembly is a wound electrode assembly, and when viewed along the first direction, the connection area overlaps with the winding center of the electrode assembly.

9. The electrochemical device according to claim 1, characterized in that The electrode assembly is a wound electrode assembly. When viewed along the first direction, the third conductive segment is a single-layer structure, and the second conductive segment, the third conductive segment and the winding center of the electrode assembly overlap at the same time.

10. The electrochemical device according to claim 2, characterized in that The electrode assembly is a wound electrode assembly, and when viewed along the first direction, the second conductive segment, the first segment, and the winding center of the electrode assembly do not overlap at the same time.

11. The electrochemical device according to claim 1, characterized in that The projection of the first conductive element in the first direction is at least partially located within the projection of the electrical connecting element in the first direction.

12. The electrochemical device according to any one of claims 1 to 11, characterized in that: The electrochemical device satisfies at least one of the following conditions: (1) A surface of the second conductive segment facing the electrode assembly and a surface of the third conductive segment facing the electrical connector are both connected to the second bent portion; (2) When viewed along the third direction, the shortest distance N1 between the second segment and the electrode assembly in the first direction H and the shortest distance N2 between the second curved portion and the electrode assembly in the first direction H satisfy: 0<N2<N1 ， Wherein, the third direction is perpendicular to the first direction; (3) When viewed along the first direction, the shortest distance N3 between the first curved portion and the side wall of the bottom case opposite thereto, and the shortest distance N4 between the second curved portion and the side wall of the bottom case opposite thereto satisfy: 0<N4<N3.

13. The electrochemical device according to any one of claims 1 to 11, characterized in that: The electrochemical device further includes a second conductive member, which is electrically connected to the electrode assembly and the shell in the shell.

14. The electrochemical device according to claim 13, characterized in that The electrode assembly is a wound electrode assembly, one end of the second conductive member is electrically connected to the outermost electrode plate of the electrode assembly, the other end of the second conductive member extends out of the bottom of the electrode assembly and bends and extends toward the bottom wall of the bottom shell, and the second end of the second conductive member is electrically connected to the bottom wall of the bottom shell.

15. The electrochemical device according to claim 14, characterized in that The first conductive member is electrically connected to the electrode assembly via a first welding point, and the second conductive member is electrically connected to the electrode assembly via a second welding point. The first welding point and the second welding point are respectively located at two ends of the electrode assembly in the second direction.

16. The electrochemical device according to claims 1-11, characterized in that: The electrical connector includes a main body and a convex portion, wherein the main body is connected to the surface of the shell cover facing the outside through the insulating layer, and the convex portion passes through the through hole and extends into the through hole to be electrically connected to the third conductive segment.

17. The electrochemical device according to claim 16, characterized in that The electrochemical device further includes a first insulating member, the first insulating member being attached to a surface of the third conductive segment facing the cavity; The third conductive segment has a connection region connected to the electrical connector, and a projection of the connection region in the first direction is located within a projection of the first insulating member in the first direction.

18. The electrochemical device according to claims 1-11, characterized in that: The electrochemical device further includes a second insulating member, which is coated on a surface of the first conductive member.

19. The electrochemical device according to any one of claims 1 to 11, characterized in that: The insulating layer is disposed around the through hole, and along the first direction, a projection of the insulating layer in the first direction is larger than a projection of the first conductive member in the first direction.

20. An electrical device, characterized in that: Comprising the electrochemical device according to any one of claims 1-19.

Images