Battery and electric device

Abstract

The invention relates to the technical field of energy storage and power devices, and particularly discloses a battery and an electric device. The battery comprises a shell, a battery cell assembly and a top cover assembly, the battery cell assembly comprises a battery cell body and a tab, the tab comprises a connecting part, a transition part and a welding part welded into a whole, and the connecting part is electrically connected with the battery cell body; the welding tooth face and the flat tooth face are arranged on the two sides of the base layer respectively, a plurality of tooth holes are formed in the welding tooth face, and a plurality of tooth face protrusions are arranged on the flat tooth face. The top cover assembly comprises a top cover plate and a pole terminal, the pole terminal is provided with a welding surface, and the welding tooth surface is in contact with the welding surface and is welded with the welding surface to form a welding bead. According to the battery, when the tabs are welded with the pole terminals, the energy loss is reduced, and the improvement of the welding efficiency and the welding quality is facilitated. And the welding part is welded with the welding surface, so that a connecting sheet is not needed, the internal resistance of the battery is reduced, a current transmission path is reduced, and more space is reserved for the battery core, thereby being beneficial to improving the energy density of the battery and increasing the capacity of the battery.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage and power devices, and more specifically, to a battery and an electrical device. Background Art

[0002] Against the backdrop of global energy conservation, emission reduction and sustainable development, it is widely expected that new energy will replace fossil energy. Currently, new energy technologies have been widely used in the fields of automobiles, heavy trucks, agricultural drones, power tools, etc.

[0003] According to different functions, power batteries have the characteristics of high energy density, long cycle life, no memory effect and environmental friendliness, and are widely used in plug-in hybrid electric vehicles, hybrid electric vehicles and pure electric vehicles. Energy storage batteries are mainly used in solar power generation equipment, wind power generation equipment and batteries for storing energy from renewable energy.

[0004] However, as the requirements for battery capacity and charging efficiency become increasingly higher, how to reduce the internal resistance of the battery, reduce the current transmission path, increase the battery capacity, and ensure welding efficiency, welding quality and reliability are technical problems that technical personnel in this field need to solve. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a battery and an electrical device, the structural design of which can effectively solve the problem of improving the welding efficiency and welding quality of the tab and the pole terminal.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] A battery cell assembly battery, comprising:

[0008] The housing is provided with a containing cavity;

[0009] A battery cell assembly is arranged in the accommodating cavity, the battery cell assembly includes a battery cell body and a pole ear, the pole ear includes a connecting portion, a transition portion and a welding portion welded together, the transition portion is arranged between the connecting portion and the welding portion, and the connecting portion is electrically connected to the battery cell body;

[0010] The welding part comprises a base layer and a welding tooth surface and a flat tooth surface respectively arranged on both sides of the base layer, the welding tooth surface is provided with a plurality of tooth holes, and the flat tooth surface is provided with a plurality of tooth surface protrusions;

[0011] The top cover assembly comprises a top cover plate and a pole terminal, wherein the top cover plate is arranged at the mouth of the accommodating cavity, the pole terminal is arranged on the top cover plate, the pole terminal is provided with a welding surface, and the welding tooth surface contacts with the welding surface and is welded to form a weld.

[0012] Optionally, in the above battery, the height of the tooth surface protrusion is smaller than the depth of the tooth hole.

[0013] Optionally, in the above battery, the thickness T of the welding portion, the depth T1 of the tooth hole, and the height T2 of the tooth surface protrusion satisfy the following relationship:

[0014] 0≤T2<T1≤T≤10mm;

[0015] 0≤T1≤3mm;

[0016] 0≤T2≤2mm.

[0017] Optionally, in the above battery, the plurality of tooth holes are distributed in an array on the welding tooth surface.

[0018] Optionally, in the above battery, the weld width W of the weld formed by welding the welding portion and the welding surface is 焊 and penetration T 焊 , satisfying the following relationship:

[0019] 0.3mm≤W 焊 ≤5.0mm;

[0020] and / or, 0.3mm≤T 焊 ≤10mm.

[0021] Optionally, in the above battery, the length L2 and width W2 of the weld mark on the flat tooth surface, and the length L1 and width W1 of the weld formed by welding the welding portion and the welding surface, satisfy the following relationship:

[0022] L1 / L2≤1;

[0023] nW1 / W2≤1;

[0024] Wherein, n is the number of the welds on the welding surface.

[0025] Optionally, in the above battery, the ratio of the area S1 of the welding portion to the area S2 of the welding surface is in the range of 0.4 to 0.9;

[0026] and / or,

[0027] The ratio of the width W of the welding portion to the width W3 of the welding surface is in the range of 0.5 to 0.98.

[0028] Optionally, in the above battery, the pole terminal comprises:

[0029] A pole, arranged on the top cover plate, and the pole is provided with a pole ear through hole;

[0030] An electrically conductive component is provided on the pole, and a pole tab gap communicating with the pole tab through hole is formed between the electrically conductive component and the pole;

[0031] The welding surface is arranged on the wall surface of the pole facing the tab gap, and the transition portion is arranged in the tab through hole so that the welding portion is welded to the welding surface.

[0032] Optionally, in the above battery, the pole includes a pole sink and a first annular protrusion provided on one end of the pole sink facing the conductive component, and the pole ear through hole and the welding surface are both provided on the pole sink.

[0033] Optionally, in the above battery, the conductive component is welded to the pole, and the first weld formed is annular, and the projection of the area surrounded by the first weld on the plane where the top cover plate is located covers the projection of the pole lug through hole on the plane where the top cover plate is located;

[0034] The pole terminal also includes a first seal, which is ring-shaped and arranged between the conductive component and the pole, and the projection of the area surrounded by the first seal on the plane where the top cover plate is located covers the projection of the pole ear through hole on the plane where the top cover plate is located.

[0035] Optionally, in the above battery, a pole sink groove is formed between the pole sink platform and the first annular protrusion, the conductive component is arranged in the pole sink groove, the outer edge of the conductive component is welded to the pole, and the first seal is arranged on the inner side of the first weld.

[0036] Optionally, in the above battery, an annular welding sink is provided on the edge of the conductive component, the welding sink is flush with the top surface of the first annular protrusion, and the welding sink and the first annular protrusion are welded at the joint.

[0037] Optionally, in the above battery, the first sealing member is disposed between the end surface of the conductive component facing the pole sink and the pole sink.

[0038] Optionally, in the above battery, the first sealing member is a first sealing ring;

[0039] The end surface of the conductive component facing the pole sink is provided with a first sealing ring groove, the first sealing ring is arranged in the first sealing ring groove, and the depth of the first sealing ring groove is less than the thickness of the first sealing ring;

[0040] Alternatively, a second sealing ring groove is provided on the end surface of the pole sink facing the conductive component, the first sealing ring is provided in the second sealing ring groove, and the depth of the second sealing ring groove is less than the thickness of the first sealing ring.

[0041] Optionally, in the above battery, the pole comprises:

[0042] A first pole part, the conductive component is welded to the first pole part, the first seal is arranged between the conductive component and the first pole part, and the pole ear through hole and the welding surface are arranged on the first pole part;

[0043] The second pole part is arranged at one end of the first pole part away from the conductive component and is sealed and fixedly connected to the first pole part. The second pole part is sealed and connected to the top cover plate. The second pole part is annular and the hollow part is connected to the pole ear through hole.

[0044] Optionally, in the above battery, the second pole portion is welded to the first pole portion.

[0045] Optionally, the above battery further includes a second annular seal, and the second seal is arranged at the connection between the second pole portion and the top cover plate.

[0046] Optionally, in the above battery, the second pole portion includes:

[0047] A base body, which is annular and sealed to the top cover plate;

[0048] The second annular protrusion is arranged at one end of the base body facing the first pole part. The second annular protrusion is welded to the first pole part and forms a receiving cavity connected to the pole ear through hole with the first pole part.

[0049] Optionally, in the above battery, the second annular protrusion comprises:

[0050] A side wall extending along a first direction, wherein a bottom end of the side wall is disposed on the base;

[0051] The inner edge extends along the second direction, the inner edge is arranged at the top end of the side wall, and the inner edge is welded to the first pole portion.

[0052] Optionally, in the above battery, a boss is provided at one end of the first pole portion facing the second pole portion, the boss is provided inside the inner edge, the top surface of the inner edge abuts against the first pole portion, and the inner edge and the boss are welded at their junction.

[0053] Optionally, in the above-mentioned battery, the conductive component includes a first conductive part and a second conductive part made of different materials, the first conductive part is welded to the first pole part, the second conductive part cooperates with and is electrically connected to the first conductive part, and the material of the first conductive part is the same as that of the first pole part.

[0054] Optionally, in the above-mentioned battery, the first pole portion with negative polarity includes a first pole portion and a second pole portion, the first pole portion is welded to the first conductive portion, the second pole portion is matched with and electrically connected to the first pole portion, the first pole portion and the first conductive portion are made of aluminum, and the second pole portion and the second conductive portion are made of copper.

[0055] Optionally, in the above battery, the material of the entire conductive component is the same as that of the first electrode portion.

[0056] Optionally, in the above battery, the entire material of the pole terminal with positive polarity is aluminum.

[0057] Optionally, the battery comprises a plurality of the pole terminals, and at least two of the plurality of pole terminals have different polarities.

[0058] Optionally, in the above-mentioned battery, the battery cell assembly also includes a tab glue layer, which is arranged at the top of the battery cell body and covers the connecting portion, and the tab glue layer extends along the extension direction of the tab to contact the battery cell body at one end and extends to contact the transition portion at the other end.

[0059] Optionally, in the above battery, the battery cell assembly further comprises an insulating sheet disposed on the top of the tab glue layer, and the insulating sheet is provided with a avoidance groove, and the transition portion is disposed in the avoidance groove.

[0060] The lead-out tabs of the battery cells of traditional batteries are stacked and welded to the pole terminals to fix the whole and ensure electrical connection. The tabs are easy to spread out, and the reflection of the laser on the surface of the tabs during laser welding will cause energy loss, affecting the welding effect. In addition, the folded tabs of traditional batteries occupy a certain amount of space in the battery cell, thus affecting the energy density of the battery. The battery provided in the present application, the tabs include a connecting portion, a transition portion and a welding portion. The connecting portion is a portion connected to the battery cell body, and the transition portion is used for the transition connection between the connecting portion and the welding portion. The tabs of the welding portion are pre-welded as a whole, that is, the welding portion is a structure welded as one, thereby avoiding the spreading of the tabs, facilitating the subsequent welding with the pole terminal, and ensuring the welding quality.

[0061] Furthermore, the welding part includes a welding tooth surface and a flat tooth surface formed on both sides of the base layer. A plurality of tooth holes are arranged on the welding tooth surface, i.e., a structure that is concave from one side of the welding tooth surface to the other side of the flat tooth surface. Through the tooth hole design, each pole piece can be reliably connected to ensure welding reliability. A tooth surface protrusion is arranged on the flat tooth surface, i.e., a structure that forms a plurality of micro-protrusions on one side of the flat tooth surface. When the pole ear and the pole terminal are welded, especially when laser welding is adopted, the laser is diffusely reflected on the flat tooth surface, thereby reducing energy loss and helping to improve welding efficiency and welding quality.

[0062] In addition, the welding tooth surface of the pole ear contacts the welding surface, and the pole ear is welded to the welding surface, which saves the space occupied by the pole ear folding, eliminates the need to set a connecting plate, reduces the internal resistance of the battery, reduces the current transmission path, and leaves more space for the battery cell, which is beneficial to improve the energy density of the battery and increase the battery capacity.

[0063] In summary, the battery cell assembly provided in the present application facilitates the welding of the pole tabs and the pole terminals, improves the welding efficiency and welding quality, increases the energy density of the battery, and increases the battery capacity.

[0064] In order to achieve the above purpose, the present application also provides an electrical device, which includes any of the above batteries. Since the above batteries have the above technical effects, the electrical device having the battery should also have corresponding technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0066] Figure 1 This is a schematic diagram of the structure of a battery according to a specific embodiment of the present application;

[0067] Figure 2 for Figure 1 Explosion diagram of

[0068] Figure 3 This is an exploded schematic diagram of a battery cell assembly according to a specific embodiment of the present application;

[0069] Figure 4 This is a schematic diagram of the structure of a pole ear of a specific embodiment of the present application;

[0070] Figure 5 is a schematic side view of a pole ear;

[0071] Figure 6a It is a schematic diagram of one side of the welding tooth surface of the pole ear;

[0072] Figure 6b This is the metallographic image of the welding tooth surface of the pole ear;

[0073] Figure 7a It is a schematic diagram of the flat tooth surface of the pole ear;

[0074] Figure 7b This is the metallographic diagram of the flat tooth surface of the pole ear;

[0075] Figure 8A schematic diagram of assembling a battery tab and a battery terminal according to a specific embodiment of the present application;

[0076] Fig. 9 A schematic cross-sectional view of welding a battery tab and a battery terminal according to a specific embodiment of the present application;

[0077] Fig.10 for Fig. 9 A magnified schematic diagram of part A;

[0078] Fig.11 It is a schematic cross-sectional diagram of the welding bead length direction of the terminal lug and the terminal post;

[0079] Fig.12 This is the metallographic diagram of the weld bead between the positive electrode lug and the pole terminal;

[0080] Fig.13 The metallographic diagram of the cross section of the weld between the positive electrode lug and the terminal post;

[0081] Fig.14 This is the metallographic diagram of the weld bead between the negative pole ear and the pole terminal;

[0082] Fig.15 The metallographic diagram of the cross section of the weld between the negative electrode lug and the terminal post;

[0083] Figure 16a~Figure 16e Schematic diagram of five different weld cross sections;

[0084] Fig.17 This is an exploded schematic diagram of a top cover assembly according to a specific embodiment of the present application;

[0085] Fig.18 This is a cross-sectional schematic diagram of a top cover assembly assembled on a battery cell assembly according to a specific embodiment of the present application;

[0086] Fig.19 A cross-sectional schematic diagram of another specific embodiment of the present application showing a top cover assembly assembled on a battery cell assembly;

[0087] Fig. 20 This is a schematic structural diagram of a top cover assembly (electrically conductive components are not shown) of another specific embodiment of the present application;

[0088] Fig.21 for Fig. 20 Schematic diagram of the reverse side;

[0089] Fig. 22 A cross-sectional schematic diagram of a top cover assembly (electrically conductive components are not shown) of a specific embodiment of the present application;

[0090] Fig.23a This is a schematic structural diagram of an electrical conduction component according to a specific embodiment of the present application;

[0091] Figure 23b for Fig.23a A schematic diagram of the reverse side of the medium conductivity component;

[0092] Fig.24 for Fig.23a A schematic cross-sectional view of a conductive component;

[0093] Fig.25a A schematic structural diagram of an electrical conduction component according to another specific embodiment of the present application;

[0094] Fig.25b for Fig.25a A schematic diagram of the reverse side of the medium conductivity component;

[0095] Fig.26 for Fig.25a A schematic cross-sectional view of a conductive component;

[0096] Fig.27a It is a cross-sectional schematic diagram of a pole terminal of a single-cell battery;

[0097] Figure 27b It is a cross-sectional schematic diagram of another pole terminal of a single-cell battery;

[0098] Fig.28a It is a cross-sectional schematic diagram of a pole terminal of a multi-core battery;

[0099] Fig.28b This is a cross-sectional schematic diagram of another pole terminal of a multi-cell battery.

[0100] Reference numerals:

[0101] 10-Battery;

[0102] 1-battery core assembly; 2-top cover assembly; 3-housing;

[0103] 11-battery core; 111-battery core body; 112-ear; 1121-connecting part; 1122-transition part; 1123-welding part; 11231-base layer; 11232-welding tooth surface; 11233-flat tooth surface; 11234-tooth hole; 11235-tooth surface protrusion;

[0104] 12-ear rubber layer; 13-insulating sheet; 131-avoidance groove; 14-Mylar film;

[0105] 21-top cover plate;

[0106] 22-pole terminal; 201-first weld; 202-second weld; 204-weld; 206-welding surface; 207-ear through hole; 208-ear gap; 209-accommodation cavity;

[0107] 221-pole; 2211-first pole portion; 22111-pole sink; 22112-first annular protrusion; 22113-pole sink groove; 22114-boss; 2212-second pole portion; 22121-base; 22122-second annular protrusion; 22122a-side wall; 22122b-inner edge;

[0108] 222-conductive component; 2221-welding sink; 2222-first sealing ring groove; 2223-first conductive part; 2224-second conductive part; 2225-contact surface; 2226-assembly surface;

[0109] 223 - first sealing member; 23 - second sealing member; 24 - first plastic member; 25 - second plastic member; 26 - explosion-proof valve; 27 - explosion-proof valve film; 31 - accommodation chamber; 32 - mouth. DETAILED DESCRIPTION

[0110] The embodiments of the present application disclose a battery and an electrical device to improve the welding efficiency, welding quality and reliability of the tab and pole terminals, increase the energy density of the battery, and increase the battery capacity.

[0111] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions 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. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0112] See also Figure 1 and Figure 2 , the battery 10 mainly includes a cell assembly 1, a top cover assembly 2 and a shell 3. The battery 10 is provided with at least one positive pole terminal and at least one negative pole terminal, and the positive pole terminal and the negative pole terminal can be arranged on the same side of the battery or on different sides of the battery. Regardless of the above-mentioned form of battery, the cell assembly 1 provided in this application can be applied. In addition, the battery 10 provided in this application includes but is not limited to square batteries, blade batteries and cylindrical batteries. The cell assembly 1 provided in this application is applicable to but not limited to batteries of different structures such as square batteries, blade batteries and cylindrical batteries. The cell assembly 1 can be a single cell, or a multi-cell structure such as a dual cell, a triple cell, a quad cell, etc. The shell 3 has a receiving cavity to place the cell assembly 1, and the shape of the shell 3 is adjusted according to the type of battery. For example, when the battery is a square battery, the shell 3 is square, and when the battery is a cylindrical battery, the shell 3 is cylindrical.

[0113] In some embodiments, the battery provided in the present application includes a housing 3, a battery cell assembly 1 and a top cover assembly 2. The housing 3 is provided with a receiving cavity, and the battery cell assembly 1 is provided in the receiving cavity 31. Specifically, the battery cell assembly 1 is provided inside the receiving cavity 31 except that part of the tab 112 extends out of the receiving cavity 31. Exemplarily, the housing 3 is made of metal to ensure the structural strength of the battery.

[0114] See also Figure 3-Figure 4 In some embodiments, the battery cell assembly 1 provided in the present application includes a battery cell 11. The number of battery cells 11 can be set as needed, such as a single cell, a dual cell, a triple cell, etc. It should be noted that the battery cell 11 can be either a wound battery cell or a laminated battery cell. The battery cell 11 includes a battery cell body 111 and a tab 112, and the battery cell body 111 is the main energy storage structure of the battery. The tab 112 extends from the top of the battery cell body 111 and is used to be welded and fixed to the pole terminal 22 of the top cover assembly 2 and electrically connected.

[0115] The pole lug 112 includes a connecting portion 1121, a transition portion 1122 and a welding portion 1123 welded together. The transition portion 1122 is provided between the connecting portion 1121 and the welding portion 1123. The connecting portion 1121 is electrically connected to the battery cell body 111. The welding portion 1123 is used to be welded to the pole terminal 22. The transition portion 1122 connects the connecting portion 1121 to the welding portion 1123. Exemplarily, the transition portion 1122 gathers the connecting portion 1121 into a sheet shape. It can be understood that the transition portion 1122, the welding portion 1123 and the connecting portion 1121 are generally an integrated structure. In the case where the pole lug 112 includes a plurality of stacked pole lug sheets, the transition portion 1122, the welding portion 1123 and the connecting portion 1121 of any pole lug sheet are an integrated structure.

[0116] The welding part 1123 includes a base layer 11231 and a welding tooth surface 11232 and a flat tooth surface 11233 respectively arranged on both sides of the base layer 11231. The welding tooth surface 11232 is provided with a plurality of tooth holes 11234, and the flat tooth surface 11233 is provided with a plurality of tooth surface protrusions 11235. The welding part 1123 is the end of the pole lug 112 after pre-welding. When the pole lug 112 includes a plurality of pole lug sheets, the pole lug sheets can be connected by pre-welding to form an integrated structure. In addition, a special morphology can be formed on the surface of the pole lug 112 by pre-welding. That is, welding tooth surfaces 11232 and flat tooth surfaces 11233 are respectively formed on both sides of the base layer 11231 of the welding part 1123. It should be noted that the term "multiple" in the present application refers to two or more. A large number of tooth holes 11234 can be specifically provided on the welding tooth surface 11232, and a large number of tooth surface protrusions 11235 can be specifically provided on the flat tooth surface 11233. When the welding portion 1123 is welded to the pole terminal 22, the welding surface 206 faces the pole terminal 22, and the flat tooth surface 11233 faces away from the pole terminal 22, that is, the weld bead 204 formed by welding passes through the flat tooth surface 11233, the base layer 11231, the welding tooth surface 11232 and the pole terminal 22 in sequence to weld and fix the pole ear 112 to the pole terminal 22.

[0117] It should be noted that, in the above technical solution, the tab 112 of the battery cell assembly 1 may be one or more, wherein at least one tab 112 includes the above-mentioned connecting portion 1121, transition portion 1122 and welding portion 1123. That is, all tabs 112 of the battery cell assembly 1 may adopt the above-mentioned structural design, or a part of the tabs 112 on the battery cell assembly 1 may adopt the above-mentioned structural design, and another part of the tabs 112 may be other structures, such as the structure of a conventional tab 112.

[0118] The top cover assembly 2 includes a top cover plate 21 and a pole terminal 22. The top cover plate 21 is arranged at the mouth 32 of the accommodating cavity 31, and the pole terminal 22 is arranged on the top cover plate 21. The pole terminal 22 is provided with a welding surface 206, and the welding tooth surface 11232 contacts the welding surface 206 and is welded to form a weld bead 204. The top cover plate 21 and the mouth 32 of the shell 3 are specifically welded and fixed to ensure the sealing of the battery. The shape of the top cover plate 21 is set accordingly according to the shape of the shell 3. The battery type of the embodiment of the present application is not limited. For example, when the battery is a square battery, the top cover plate 21 is square, and when the battery is a cylindrical battery, the top cover plate 21 is round. It can be understood that the welding tooth surface 11232 of the welding portion 1123 contacts the welding surface 206, and the weld bead 204 passes through the flat tooth surface 11233 of the pole tab 112 → the base layer 11231 → the welding tooth surface 11232 → the welding surface 206 of the pole terminal 22 from top to bottom, and the pole terminal 22 is welded and fixed to the pole tab 112. It should be noted that the welding of the welding portion 1123 and the welding surface 206 includes but is not limited to penetration welding such as laser welding.

[0119] The pole tabs led out of the battery cell 11 of a traditional battery are stacked and welded to the pole terminal 22 to fix the whole and ensure electrical connection. The pole tabs are easy to spread out, and the reflection of the laser on the surface of the pole tab 112 during laser welding will cause energy loss, affecting the welding effect. In the battery cell assembly 1 provided in the present application, the pole tab 112 includes a connecting portion 1121, a transition portion 1122 and a welding portion 1123. The connecting portion 1121 is a portion connected to the battery cell body 111, and the transition portion 1122 is used for the transition connection between the connecting portion 1121 and the welding portion 1123. The pole tabs 112 of the welding portion 1123 are pre-welded as a whole, that is, the welding portion 1123 is a structure welded as one, thereby avoiding the spreading of the pole tabs, facilitating the subsequent welding with the pole terminal 22, and ensuring the welding quality.

[0120] Furthermore, the welding portion 1123 includes a welding tooth surface 11232 and a flat tooth surface 11233 formed on both sides of the base layer 11231. A plurality of tooth holes 11234 are provided on the welding tooth surface 11232, i.e., a structure that is concave from one side of the welding tooth surface 11232 to the other side of the flat tooth surface 11233. Through the design of the tooth holes 11234, each pole tab can be reliably connected, thereby ensuring welding reliability. A tooth surface protrusion 11235 is provided on the flat tooth surface 11233, i.e., a structure that forms a plurality of micro-protrusions on one side of the flat tooth surface 11233. When the pole tab 112 is welded to the pole terminal 22, especially when laser welding is adopted, the laser is diffusely reflected on the flat tooth surface 11233, thereby reducing energy loss and helping to improve welding efficiency and welding quality.

[0121] In addition, the folding of the conventional battery tabs occupies a certain space of the battery cell 11, thus affecting the energy density of the battery. In this technical solution, the welding tooth surface 11232 of the tab 112 contacts the welding surface 206, and the tab 112 is welded to the welding surface 206, which saves the space occupied by the tab 112 folding, does not need to set a connecting sheet, reduces the internal resistance of the battery, reduces the current transmission path, and leaves more space for the battery cell 11, which is conducive to improving the energy density of the battery and increasing the battery capacity.

[0122] In summary, the battery cell assembly 1 provided in the present application facilitates the welding of the pole ear 112 and the pole terminal 22, improves the welding efficiency and welding quality, increases the energy density of the battery, and increases the battery capacity.

[0123] In some embodiments, see Figure 5, the height T2 of the tooth surface protrusion 11235 is less than the depth T1 of the tooth hole 11234. The tooth hole 11234 has a relatively large depth, so it can better connect the tab pieces of each layer, that is, ensure the formation of a fixed constraint on the multi-layer tab pieces. At the same time, the height of the tooth surface protrusion 11235 is relatively small, which is convenient for penetration during welding. The weld bead 204 melt extends on the flat tooth surface 11233 and fills the tooth hole 11234 of the welded tooth surface 11232. In addition, the flat tooth surface 11233 is close to a plane, which can reduce specular reflection and ensure that there are no welding defects such as explosion welding and false welding during welding. It should be noted that for multiple tooth holes 11234, their depths can be the same or different, and for multiple tooth surface protrusions 11235, their heights can also be the same or different. When the depths of multiple tooth holes 11234 are different, the maximum value, minimum value or average value of the depth of the tooth hole 11234 can be taken for the above comparison; when the heights of multiple tooth surface protrusions 11235 are different, the minimum value, maximum value or average value of the height of the tooth surface protrusion 11235 can be taken for the above comparison.

[0124] In some embodiments, please refer to Figure 5 , the thickness T of the welding part 1123, the depth T1 of the tooth hole 11234, and the height T2 of the tooth surface protrusion 11235 satisfy the following relationship: 0 ≤ T2 < T1 ≤ T ≤ 10 mm. The depth T1 of the tooth hole 11234 is greater than the height T2 of the tooth surface protrusion 11235, and both are less than the thickness of the welding part 1123, that is, the tooth hole 11234 does not penetrate the welding part 1123, that is, the tooth hole 11234 is a blind hole rather than a through hole. The thickness T of the welding part 1123 is not greater than 10 mm, which ensures that it can penetrate when welding with the pole terminal 22. And the above settings are conducive to ensuring welding reliability and consistency. Preferably, 0 ≤ T2 < T1 ≤ T ≤ 3 mm.

[0125] Exemplarily, 0 ≤ T1 ≤ 3 mm. The depth T1 of the tooth hole 11234 ranges from 1 to 3 mm. It can be understood that when the depth T1 of the tooth hole 11234 is 0, the welded tooth surface 11232 is flat. Exemplarily, the depth T1 of at least one tooth hole 11234 is within the above range. Preferably, 0 ≤ T1 ≤ 1 mm, that is, the depth T1 of the tooth hole 11234 ranges from 0 to 1 mm. Most preferably, 0.05 ≤ T1 ≤ 0.5 mm, that is, the depth T1 of the tooth hole 11234 ranges from 0.05 to 0.5 mm. For example, the depth T1 of the tooth hole 11234 is 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm. When the depth T1 of the tooth hole 11234 is within the above range, it can not only ensure the reliable connection of the stacked tab pieces, but also ensure the structural strength of the overall welding part 1123 after welding.

[0126] Exemplarily, 0≤T2≤2mm. The height T2 of the tooth surface protrusion 11235 ranges from 0 to 2mm. It can be understood that when the height T2 of the tooth surface protrusion 11235 is 0, the corresponding flat tooth surface 11233 is flat. Exemplarily, the height T2 of at least one tooth surface protrusion 11235 is within the above range. Preferably, 0≤T2≤0.5mm, that is, the height T2 of the tooth surface protrusion 11235 ranges from 0 to 0.5mm. Most preferably, 0≤T2≤0.3mm, that is, the height T2 of the tooth surface protrusion 11235 ranges from 0 to 0.3mm, such as the height T2 of the tooth surface protrusion 11235 is 0.02mm, 0.04mm, 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm. When the height T2 of the tooth surface protrusion 11235 is within the above range, it can achieve diffuse reflection of the laser on the flat tooth surface 11233 and reduce energy loss, while avoiding poor welding such as explosive welding and cold welding.

[0127] In some embodiments, see Figure 4 , a plurality of tooth holes 11234 are distributed in an array on the welding tooth surface 11232. The tooth holes 11234 are distributed in an array, which is convenient for forming, and at the same time, the fixing effect of the tooth holes 11234 on the welding part 1123 can be evenly distributed on the welding part 1123, further ensuring the reliability of the welding part 1123.

[0128] In some embodiments, see Figure 4 , multiple tooth surface protrusions 11235 are irregularly distributed on the flat tooth surface. Exemplarily, on the flat tooth surface 11233, along the width direction and the length direction, adjacent tooth surface protrusions 11235 are staggered and arranged, and the tooth surface protrusions 11235 are irregular in shape. Such an arrangement can achieve better diffuse reflection.

[0129] In some embodiments, see Figure 6a-6b, the length a and width b of a single tooth hole 11234 are both in the range of 0-5 mm. Preferably, the length a and width b of the tooth hole 11234 are both in the range of 0.1-1 mm. Most preferably, the length a and width b of the tooth hole 11234 are both in the range of 0.2-1 mm, such as the length a of the tooth hole 11234 is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm; the length b of the tooth hole 11234 is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm. It should be noted that the length a and width b of the tooth hole 11234 can be the same or different. When the length a and width b of the tooth hole 11234 are the same, the tooth hole 11234 can be square or ring-shaped. The length a and width b of the tooth hole 11234 are set within the above range, which can ensure that the weld 204 will not have a burst point or the solute of the weld 204 cannot fill the tooth hole 11234 passed through, thereby ensuring the reliability and yield of welding.

[0130] In some embodiments, the battery cell assembly 1 further includes a tab glue layer 12, which covers one end of the connection portion 1121 facing the top cover assembly 2, and the tab glue layer 12 extends along the extension direction of the tab 112 to contact the battery cell body 111 at one end, and extends to contact the transition portion 1122 at the other end. The tab glue layer 12 covers the entire connection portion 1121 and extends upward along the transition portion 1122 and does not exceed the tab through hole on the pole terminal 22, and extends downward to part of the battery cell body 111 to prevent the tab 112 from short-circuiting. Exemplarily, the tab glue layer 12 is a tab 112 adhesive tape.

[0131] In some embodiments, the battery cell assembly 1 further includes an insulating sheet 13, the insulating sheet 13 is provided with a avoidance groove 131, the transition portion 1122 is provided in the avoidance groove 131, and part of the tab glue layer 12 is located between the connecting portion 1121 and the insulating sheet 13. The avoidance groove 131 corresponding to the through hole of the tab 112 on the pole terminal 22 is provided on the insulating sheet 13, so as to facilitate the tab 112 to extend along the avoidance groove 131, and the insulating sheet 13 can prevent the tab 112 from short-circuiting and compressing the battery cell body 111, and can also reduce costs. Furthermore, the top of the tab glue layer 12 is provided in the avoidance groove 131.

[0132] In some embodiments, the battery cell assembly 1 further includes a Mylar film 14, which is wrapped around the battery cell body 111, and the opening portion is folded onto the insulating sheet 13, so that the entire battery cell assembly 1 is bound and insulated short-circuited. Exemplarily, the battery cell assembly 1 is sequentially provided with the Mylar film 14, the insulating sheet 13, the tab glue layer 12, and the battery cell 11 from the outside to the inside, which are mutually wrapped and constrained.

[0133] In some embodiments, see Figure 7a-Figure 7b and Figure 9-Figure 15 , the length L2 of the weld mark on the flat tooth surface 11233, the width W2 of the weld mark on the flat tooth surface 11233, the length L1 and the width W1 of the weld bead 204 formed by welding the welding portion 1123 and the welding surface 206, satisfy the following relationship: L1 / L2≤1; nW1 / W2≤1, where n is the number of weld beads 204 on the welding surface 206, Figure 7a There are two weld beads 204. The weld beads 204 and the flat tooth surface 11233 satisfy the above-mentioned dimensional relationship, which can ensure the welding yield and current capacity.

[0134] In some embodiments, the width W2 of the weld mark of the flat tooth surface 11233 is in the range of 1 to 10 mm, and the width W1 of the weld bead 204 is in the range of 0.5 to 3 mm. Exemplarily, the width W2 of the weld mark of the flat tooth surface 11233 is 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm. The width W1 of the weld bead 204 is 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm. As set above, the melt penetrating the weld bead 204 can fill the tooth depth of the flat tooth surface and the weld tooth surface to ensure the consistency of the weld bead welding.

[0135] In some embodiments, see Figure 10-15 The weld width W of the weld bead 204 formed by welding the weld portion 1123 and the weld surface 206 is 焊 Satisfy the following relationship: 0.3mm≤W 焊 ≤5.0mm. Preferably, 0.5mm≤W 焊 ≤5.0mm. For example, the weld width W of the weld bead 204 formed by welding the weld portion 1123 and the weld surface 206 is 焊 The weld width W of the weld bead 204 formed by welding the weld portion 1123 and the weld surface 206 is 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm. 焊 Setting it within the above range can effectively ensure the reliability and sealing of the weld.

[0136] In some embodiments, see Figure 10-15 The penetration depth T of the weld bead 204 formed by welding the weld portion 1123 and the weld surface 206 is 焊 Satisfy the following relationship: 0.3mm≤T 焊 ≤10mm. Preferably, 0.3mm≤T 焊 ≤3mm. For example, the penetration depth T of the weld bead 204 formed by welding the weld portion 1123 and the weld surface 206 is 焊The penetration depth T of the weld bead 204 formed by welding the weld portion 1123 to the weld surface 206 is 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, and 10 mm. 焊 Setting it within the above range can effectively ensure the reliability and sealing of the weld.

[0137] In some embodiments, the cross-sectional shape of the weld bead 204 formed by welding the welding portion 1123 and the welding surface 206 is semicircular, acute triangle, trapezoidal, double wave peak or columnar. Fig.16a is a schematic diagram of a semicircular weld bead 204, Fig.16b is a schematic diagram of a sharp triangle weld 204, Fig.16c is a schematic diagram of a trapezoidal weld bead 204, Fig.16d is a schematic diagram of a double wave weld bead 204, Fig.16e Schematic diagram of columnar weld 204. To effectively ensure the reliability and sealing of the weld, the weld 204 formed by welding the welding portion 1123 and the welding surface 206 preferably has a semicircular, acute triangle or columnar cross section.

[0138] In some embodiments, see Figure 8 and Fig. 9 , the ratio of the area S1 of the welding portion 1123 of the tab 112 to the area S2 of the welding surface 206 of the pole terminal 22 is in the range of 0.4 to 0.9, that is, the range of S1 / S2 is 0.4 to 0.9. Preferably, the range of S1 / S2 is 0.6 to 0.9. Most preferably, the range of S1 / S2 is 0.6 to 0.85. Exemplarily, S1 / S2 is 0.4, 0.5, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9. When the welding portion 1123 and the welding surface 206 are both rectangular, the length of the welding portion 1123 is L and the width is W, the area S1 of the welding portion 1123 is L*W, the length of the welding surface 206 is L3 and the width is W3, and the area S2 of the welding surface 206 is L3*W3. By setting S1 / S2 within the above range, the effective welding area and current flow capacity between the welding portion 1123 and the welding surface 206 can be ensured.

[0139] In some embodiments, see Figure 8 and Fig. 9, the ratio of the width W of the welding portion 1123 to the width W3 of the welding surface 206 is in the range of 0.5 to 0.98, that is, the range of W / W3 is 0.5 to 0.98. Preferably, the range of W / W3 is 0.7 to 0.9. Exemplarily, W / W3 is 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.98. Setting W / W3 within the above range can ensure the effective area and flow capacity of the welding portion 1123 and the welding surface 206. In order to ensure the flow energy, the larger the size of the welding portion 1123 and the welding surface 206, the better the flow capacity can be provided, but the larger the size, the larger the size of the corresponding battery and the higher the cost. Therefore, setting S1 / S2 and W / W3 within the above range can provide good flow capacity while taking into account the battery size and cost.

[0140] See also Figure 18-Figure 21 In some embodiments, the pole terminal 22 provided in the present application includes a pole 221 and an electrically conductive component 222. The pole 221 is conductive and is used to be electrically connected to the pole ear 112 of the battery cell assembly 1. The pole 221 is provided with a pole ear through hole 207, and the pole ear 112 can be inserted into the pole ear through hole 207 and contact and conduct with the pole 221. In addition, the provision of the pole ear through hole 207 also connects the side of the pole 221 away from the battery cell assembly with the accommodating cavity 31. The number of the pole ear through holes 207 can be set as needed, and is not specifically limited here. For example, according to the number of pole ears 112, the specific pole ear through hole 207 can be set to one or more. Exemplarily, the number of the pole ear through holes 207 is 1 to 4. It should be noted that the multiple in the present application refers to two or more. The pole ear cavity 205 includes a pole ear through hole 207.

[0141] The conductive component 222 is provided on the pole 221, and a pole tab gap 208 connected to the pole tab through hole 207 is formed between the conductive component 222 and the pole 221; the welding surface 206 is provided on the wall of the pole 221 facing the pole tab gap 208, and the transition portion 1122 is provided in the pole tab through hole 207 so that the welding portion 1123 is welded to the welding surface 206. The pole tab through hole 207 provides a storage space for the transition portion 1122, and the pole tab gap 208 provides a storage space for the welding portion 1123. In this embodiment, when the top cover assembly 2 is assembled with the battery cell assembly 1, the pole tab 112 passes through the pole tab through hole 207 and enters the pole tab gap 208, and the end of the pole tab 112, i.e., the welding portion 1123, is folded to contact with the welding surface 206, and the welding portion 1123 is fixed and electrically connected to the welding surface 206 by welding.

[0142] In some embodiments, the pole 221 includes a pole sink 22111 and a first annular protrusion 22112 disposed at one end of the pole sink 22111 facing the conductive component 222, and the pole ear through hole 207 and the welding surface 206 are both disposed on the pole sink 22111. It can be understood that the pole sink 22111 and the first annular protrusion 22112 can be either an integrated structure or a split structure connected by a conventional fixing method. The welding surface 206 is disposed on the pole sink 22111, so that the space is fully utilized, and the welding portion 1123 can be conveniently folded to the pole sink 22111 after passing through the pole ear through hole 206, and the welding tooth surface 11232 is in contact with the welding surface 206. With such a configuration, the pole 221 and the pole ear 112 are reliably welded.

[0143] In some embodiments, the conductive component 222 is welded to the pole 221, and the first weld 201 formed is annular. It should be noted that the annular or ring-shaped in the present application refers to a circle, and its shape is not specifically limited, such as a circular ring, a triangular ring, a square ring, an irregular ring, etc. The projection of the area surrounded by the first weld 201 on the plane where the top cover plate 21 is located covers the projection of the pole ear through hole 207 on the plane where the top cover plate 21 is located. For example, please refer to Fig.18 , taking the plane where the top cover plate 21 is located as the reference plane A, the projection of the area surrounded by the first weld 201 on the reference plane A covers the projection of the tab through hole 207 on the reference plane A, or in other words, the projection of the first weld 201 on the reference plane A is set outside the projection of the tab through hole 207 on the reference plane A or is aligned with it, so that the first weld 201 forms a seal between the conductive component 222 and the pole 221. It can be understood that when the tab through hole 207 is inclined relative to the top cover plate 21, or the tab through hole 207 is an irregular hole, the projection of the tab through hole 207 on the plane where the top cover plate 21 is located refers to the projection of the end of the tab through hole 207 facing the conductive component 222 on the plane where the top cover plate 21 is located. In addition, when there are multiple tab through holes 207, the projection of the area surrounded by the first weld 201 on the plane where the top cover plate 21 is located covers the projection of each tab through hole 207 on the plane where the top cover plate 21 is located.

[0144] The conductive component 222 cooperates with the pole 221 to close the end of the pole 221 away from the battery cell assembly, thereby preventing the electrolyte in the housing cavity 31 from leaking through the pole ear through hole 207. In addition, it can be understood that the conductive component 222 has a conductive property, and the conductive component 222 is welded to the pole 221, so the conductive component 222 is used to conveniently realize the indirect electrical connection between the pole 221 and the converging component, etc., and it is beneficial to increase the connection area of ​​the electrical connection, thereby helping to reduce the resistance of the electrical connection. In addition, the conductive component 222 cooperates with the pole 221, which facilitates the forming of the pole ear through hole 207 and the welding operation of the pole ear 112 with the pole 221 after it is inserted into the pole ear through hole 207. During processing, the pole lug 112 can first be passed through the pole lug through hole 207 and welded to the wall surface of the pole 221 facing the conductive component 222 , and then the conductive component 222 and the pole 221 can be welded to fix the connection and achieve sealing between the conductive component 222 and the pole 221 .

[0145] A first seal 223 is also provided between the conductive component 222 and the pole 221. The first seal 223 is annular, and the projection of the area surrounded by the first seal 223 on the plane where the top cover plate 21 is located covers the projection of the pole ear through hole 207 on the plane where the top cover plate 21 is located. In the present application, the number of first seals 223 can be one or more. Exemplarily, the number of first seals 223 is 1 to 4, so as to take into account the assembly space while ensuring the sealing effect. For example, please refer to Fig.18 , taking the plane where the top cover plate 21 is located as the reference plane A, the projection of the area surrounded by the first seal 223 on the reference plane A covers the projection of the pole lug through hole 207 on the reference plane A, or in other words, the projection of the first seal 223 on the reference plane A is sleeved outside the projection of the pole lug through hole 207 on the reference plane A or is aligned with it, so that the first seal 223 constitutes another seal between the conductive component 222 and the pole 221. In addition, when there are multiple pole lug through holes 207, the projection of the area surrounded by the first seal 223 on the plane where the top cover plate 21 is located covers the projection of each pole lug through hole 207 on the plane where the top cover plate 21 is located. It should be noted that the form of the first seal 223 is not specifically limited here. Exemplarily, the first seal 223 adopts a sealing ring, which has a simple structure and is easy to assemble.

[0146] It should be noted that, in the above technical solution, the pole terminal 22 of the top cover assembly may be one or more, wherein at least one pole terminal 22 includes the above-mentioned pole 221, the conductive component 222 and the first seal 223. That is, all pole terminals 22 of the top cover plate 21 may adopt the above-mentioned structural design, or a part of the pole terminals 22 on the top cover plate 21 may adopt the above-mentioned structural design, and another part of the pole terminals 22 may have other structures, such as the structure of a conventional pole terminal 22.

[0147] In this embodiment, the conductive component 222 is welded to the pole 221, and the first weld 201 forms a seal between the conductive component 222 and the pole 221. At the same time, a first seal 223 is provided between the conductive component 222 and the pole 221, and the first seal 223 forms another seal between the conductive component 222 and the pole 221. The double seal increases the sealing reliability of the pole 221 and the conductive component 222, and improves the safety of the battery.

[0148] In some embodiments, a pole sink 22113 is formed between the pole sink 22111 and the first annular protrusion 22112, and the conductive component 222 is arranged in the pole sink 22113. On the one hand, the pole sink 22111 can position the conductive component 222 in the first direction; on the other hand, the first annular protrusion 22112 can position the side of the conductive component 222, that is, it can position the conductive component 222 in the second direction and the third direction. The first direction is the arrangement direction of the pole terminal 22 and the conductive component 222, Fig.18 In the figure, the first direction is the up-down direction of the paper. The second direction and the third direction are respectively perpendicular to the first direction. Fig.18 In the figure, the second direction is the left-right direction, and the third direction is the direction perpendicular to the paper. Exemplarily, the first direction is the height direction of the battery, the second direction is the thickness direction of the battery, and the third direction is the width direction of the battery. In this embodiment, through the cooperation between the pole sink 22111 and the first annular protrusion 22112, the conductive component 222 can be well positioned, thereby facilitating the assembly and precise positioning of the conductive component 222, and facilitating the welding of the first annular protrusion 22112 of the conductive component 222.

[0149] In some embodiments, the outer edge of the conductive component 222 is welded to the pole 221, and the first seal 223 is arranged on the inner side of the first weld 201. It can be understood that the first seal 223 is arranged on the inner side of the first weld 201, specifically, the projection of the first seal 223 on the plane where the top cover plate 21 is located is arranged inside the projection of the first weld 201 on the plane where the top cover plate 21 is located. In this technical solution, the first seal 223 forms a primary seal between the conductive component 222 and the pole 221, and the first weld 201 forms a secondary seal between the conductive component 222 and the pole 221. Due to the sealing effect of the first seal 223, when the materials of the contact position of the conductive component 222 and the pole 221 are different, the area of ​​the electrolyte volatilized to the contact position of the conductive component 222 and the pole 221 after gasification is reduced, thereby reducing the potential difference formed and the electrochemical corrosion caused thereby. Therefore, the safety of the battery is further improved.

[0150] Exemplarily, the first seal 223 is disposed at the innermost side of the contact position between the conductive component 222 and the pole 221. That is, the contact position between the conductive component 222 and the pole 221 is isolated outside the first seal 223. Due to the sealing effect of the first seal 223, when the materials of the contact position between the conductive component 222 and the pole 221 are different, the electrolyte is prevented from volatilizing to the contact position between the conductive component 222 and the pole 221 after vaporization, thereby avoiding the potential difference and electrochemical corrosion caused thereby.

[0151] In some embodiments, see Figure 8 and Fig. 9 , the length L4 of the pole sink 22111, the width W4 of the pole sink 22111, the length L3 of the welding surface 206, and the width W3 of the welding surface 206 satisfy the relationship: 0.2≤L3 / L4≤1, 0.2≤W3 / W4<1. The preferred setting is 0.4≤L3 / L4≤0.95, and the most preferred setting is 0.4≤W3 / W4≤0.9. As set above, the cost can be reduced and the welding current capacity can be satisfied.

[0152] In some embodiments, see Figure 18-Figure 22 and Fig.23a and Figure 23b The edge of the conductive component 222 is provided with an annular welding sink 2221, the welding sink 2221 is flush with the top surface of the first annular protrusion 22112, and the welding sink 2221 is welded at the junction with the first annular protrusion 22112. The welding sink 2221 is formed by sinking the edge of the top surface of the conductive component 222, that is, the thickness of the welding sink 2221 in the first direction is less than the thickness of the middle part of the conductive component 222 in the first direction. The welding sink 2221 is flush with the top surface of the first annular protrusion 22112, and welding is performed from the connection between the two to ensure welding quality.

[0153] In some embodiments, see Fig.24 , the thickness T0 of the conductive component 222 in the first direction is greater than 1mm, and the depth T3 of the welding sink 2221 in the first direction is not less than 0.1mm. Such a setting can ensure that the conductive component 222 is reliably connected and electrically conductive with the pole terminal 22, and prevent the weld from being higher than the top surface of the conductive component 222 after welding, affecting the welding of the top cover assembly with components such as the busbar. Exemplarily, the thickness T0 of the conductive component 222 in the first direction ranges from 2 to 5mm, such as 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm. The depth T3 of the welding sink 2221 in the first direction ranges from 0.15 to 2mm, such as 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm or 2mm. Such a setting can reduce the weight of the conductive component 222, thereby reducing the weight of the top cover assembly and the battery, reducing costs, and at the same time helping to ensure the production yield.

[0154] In some embodiments, the first seal 223 is disposed between the end face of the conductive component 222 facing the pole sink 22111 and the pole sink 22111. The pole sink 22111 can be abutted against the end face of the conductive component 222 facing the pole sink 22111 for positioning, and the first seal 223 is disposed between the two action surfaces, that is, between the end faces of the pole sink 22111 and the conductive component 222 opposite in the first direction, so that the seal is reliable and the assembly is convenient. Exemplarily, the first seal 223 is disposed at a position adjacent to the pole sink 22111 and the pole ear through hole 207, so as to completely prevent the electrolyte from volatilizing to the contact position between the conductive component 222 and the pole 221 after gasification.

[0155] In some embodiments, the first sealing member 223 is a first sealing ring. Exemplarily, the material of the first sealing ring can be PFA (Polyfluoroalkoxy, soluble polytetrafluoroethylene), fluororubber, silicone rubber, nitrile rubber, etc., and the first sealing ring can be an O-ring, a rectangular sealing ring, a Y-shaped sealing ring, etc. To ensure air tightness, fluororubber and PFA are preferably used. The first sealing member 223 adopts a first sealing ring, which has a simple structure and is easy to assemble. Exemplarily, the compression range of the first sealing ring is 10% to 50%, such as 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%, to ensure sealing performance. In other embodiments, the first sealing member 223 may also adopt other sealing structures.

[0156] In some embodiments, see Fig.23a and Figure 23b , the end surface of the conductive component 222 facing the pole sink 22111 is provided with a first sealing ring groove 2222, and the first sealing ring is provided in the first sealing ring groove 2222, and the depth of the first sealing ring groove 2222 in the first direction is less than the thickness of the first sealing ring, so as to squeeze the first sealing ring between the first sealing ring groove 2222 and the pole terminal 22. It can be understood that the first sealing ring groove 2222, that is, the annular groove provided on the end surface of the conductive component 222, can play a positioning role for the first sealing ring, facilitate the assembly of the first sealing ring, and prevent the first sealing ring from being squeezed and displaced, thereby improving the sealing reliability. The number of the first sealing ring grooves 2222 is set correspondingly to the number of the first sealing rings, that is, when one first sealing ring is provided, one first sealing ring groove 2222 is provided accordingly; when multiple first sealing rings are provided, multiple first sealing ring grooves 2222 are provided accordingly, and the multiple first sealing ring grooves 2222 are arranged and distributed in sequence.

[0157] For example, see Fig.24, the depth T4 of the first sealing ring groove 2222 in the first direction is not less than 0.15mm, so as to effectively position the first sealing ring. Preferably, the depth T4 of the first sealing ring groove 2222 in the first direction ranges from 0.2 to 1.5mm, such as 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.5mm, etc. The depth of the first sealing ring groove 2222 is set as above, which can ensure the sealing compression of the first sealing ring, thereby ensuring the sealing effect.

[0158] The above embodiments illustrate that a first sealing ring groove 2222 is provided on the conductive component 222 to position the first sealing member 223. In other embodiments, a sealing ring groove for positioning the first sealing ring may also be provided on the pole 221. A second sealing ring groove is provided on the end surface of the pole sink 22111 facing the conductive component 222, and the first sealing ring is provided in the second sealing ring groove. The depth of the second sealing ring groove in the first direction is less than the thickness of the first sealing ring. The corresponding setting of the second sealing ring groove can refer to the above-mentioned first sealing ring groove 2222, which will not be repeated here. In other embodiments, a first sealing ring groove 2222 may also be provided on the conductive component 222, and a second sealing ring groove is provided on the end surface of the pole sink 22111 facing the conductive component 222. The sum of the depths of the first sealing ring groove 2222 and the second sealing ring groove in the first direction is not greater than the thickness of the first sealing ring, so as to ensure the sealing compression amount of the first sealing ring.

[0159] In some embodiments, see Figure 18-Figure 22, the pole 221 includes a first pole part 2211 and a second pole part 2212. The conductive component 222 is welded to the first pole part 2211, the first seal 223 is arranged between the conductive component 222 and the first pole part 2211, the pole ear through hole 207 and the welding surface 206 are arranged on the first pole part 2211; the second pole part 2212 is arranged at one end of the first pole part 2211 away from the conductive component 222 and is sealed and fixedly connected to the first pole part 2211, the second pole part 2212 is sealed and connected to the top cover plate 21, the second pole part 2212 is annular and the hollow part is connected to the pole ear through hole 207. In this embodiment, the pole 221 adopts a split structure, that is, it includes a split first pole part 2211 and a second pole part 2212, and illustratively, the first pole part 2211 and the second pole part 2212 are distributed along the first direction. The first pole part 2211 is used to cooperate with the conductive component 222, and the corresponding first sealing member 223 and the pole ear through hole 207 are both provided on the first pole part 2211. The second pole part 2212 is used to cooperate with the top cover plate 21, and the second pole part 2212 is annular, and its annular hollow part is connected with the pole ear through hole 207 to avoid the pole ear 112, so that the pole ear 112 can be passed through the pole ear through hole 207. The second pole part 2212 is sealed and fixedly connected to the first pole part 2211, ensuring the airtightness of the top cover assembly. The pole terminal 22 adopts a split structure of the first pole part 2211 and the second pole part 2212, which can reduce the manufacturing difficulty and improve the production efficiency.

[0160] When the pole 221 includes the pole sink 22111 and the first annular protrusion 22112, both are parts of the first pole portion 2211. That is, the first pole portion 2211 includes the pole sink 22111 and the first annular protrusion 22112, so as to facilitate welding with the conductive component 222 and the arrangement of the first seal 223.

[0161] In some embodiments, the second pole part 2212 is welded to the first pole part 2211. The second pole part 2212 and the first pole part 2211 are fixedly connected by welding, which is convenient to prepare and reliable to connect. Moreover, welding can not only realize the sealing of the second pole part 2212 and the first pole part 2211, but also realize the electrical conduction between the two, thus simplifying the structure and the assembly process.

[0162] In some embodiments, the top cover assembly 2 also includes a second annular seal 23, and the second seal 23 is arranged at the connection between the second pole portion 2212 and the top cover plate 21. The top cover plate 21 and the second pole portion 2212 are sealed by the second seal 23, which is easy to assemble and has reliable sealing. In the present application, the number of the second seal 23 can be one or more. It should be noted that the form of the second seal 23 is not specifically limited here. Exemplarily, the second seal 23 adopts a second sealing ring, which has a simple structure and is easy to assemble. The material of the second sealing ring can be PFA (Polyfluoroalkoxy, soluble polytetrafluoroethylene), fluororubber, silicone rubber, nitrile rubber, etc., and the first sealing ring can be an O-ring, a rectangular sealing ring, a Y-shaped sealing ring, etc. To ensure airtightness, fluororubber and PFA are preferably used.

[0163] In some embodiments, the second pole part 2212 includes a base 22121 and a second annular protrusion 22122. The base 22121 is annular, and the base 22121 is sealed and connected to the top cover plate 21; the second annular protrusion 22122 is provided at one end of the base 22121 facing the first pole part 2211, and the second annular protrusion 22122 is welded to the first pole part 2211, and the second annular protrusion 22122 and the first pole part 2211 form a receiving cavity 209 connected to the pole ear through hole 207. The pole ear cavity 205 includes the pole ear through hole 207, the pole ear gap 208 and the receiving cavity 209. It can be understood that the second annular protrusion 22122 and the base 22121 can be an integrated structure, or a split structure connected by a conventional fixing method. The base 22121 can cooperate with the top cover plate 21 to compress the second sealing ring for sealing. The accommodating cavity surrounded by the second annular protrusion 22122 and the first pole portion 2211 can accommodate the pole ear 112. Specifically, the transition portion 1122 of the pole ear 112 is penetrated through the accommodating cavity 209, and the top cover assembly further provides an accommodating space for the pole ear 112, thereby reducing the internal space of the battery occupied by the pole ear 112, and further helping to increase the capacity of the battery.

[0164] In some embodiments, see Fig. 22The second annular protrusion 22122 includes a side wall 22122a and an inner edge 22122b. The side wall 22122a extends along the first direction, and the bottom end of the side wall 22122a is arranged on the base 22121; the inner edge 22122b extends along the second direction, and the inner edge 22122b is arranged on the top end of the side wall 22122a, and the inner edge 22122b is welded to the first pole part 2211. It can be understood that the side wall 22122a and the inner edge 22122b can be an integral structure, or a split structure connected by a conventional fixing method. The bottom end of the side wall 22122a is one end of the side wall 22122a away from the conductive component 222 along the first direction, and the top end is the other end opposite thereto. The side wall 22122a encloses a housing cavity 209 to provide a housing space for the pole ear 112. The inner edge 22122b is provided to facilitate welding with the first pole portion 2211 to ensure welding quality.

[0165] In some embodiments, a boss 22114 is provided at one end of the first pole portion 2211 facing the second pole portion 2212, and the boss 22114 is provided inside the inner edge 22122b, the top surface of the inner edge 22122b abuts against the first pole portion 2211, and the inner edge 22122b and the boss 22114 are welded at their joints. In the case where the first pole portion 2211 includes the pole sink 22111 and the first annular protrusion 22112, the boss 22114 is provided on the back side of the pole sink 22111, that is, the end surface away from the conductive component 222. In this embodiment, on the one hand, the first pole portion 2211 can play a positioning role on the inner edge 22122b of the second pole portion 2212 in the first direction; on the other hand, the boss 22114 can play a positioning role on the inner side surface of the inner edge 22122b, that is, it plays a positioning role in the second direction and the third direction. Therefore, through the cooperation between the boss 22114 and the inner edge 22122b, the second pole part 2212 can be well positioned, so as to facilitate the assembly and accurate positioning of the second pole part 2212 and the first pole part 2211, and facilitate welding the two. Exemplarily, the second weld 202 is formed by welding at the junction of the inner edge 22122b and the boss 22114.

[0166] In some embodiments, the pole 221 and the conductive component 222 are made of metal to provide good conductivity. For example, the pole 221 and the conductive component 222 can be made of copper, aluminum, copper-aluminum composite, copper-steel composite, etc.

[0167] In some embodiments, see Figure 23a-23b and Fig.24, the conductive component 222 includes a first conductive part 2223 and a second conductive part 2224 of different materials, the first conductive part 2223 is welded to the first pole part 2211, the second conductive part 2224 is matched with and electrically connected to the first conductive part 2223, and the material of the first conductive part 2223 is the same as that of the first pole part 2211. That is, the conductive component 222 adopts a composite structure, and the first conductive part 2223 is set to be the same material as the first pole part 2211, so as to facilitate the electrical connection between the first conductive part 2223 and the first pole part 2211, such as by welding, so that the first conductive part 2223 and the first pole part 2211 can be reliably and stably connected. In addition, since the second conductive part 2224 and the first conductive part 2223 are made of different materials, it is convenient to use the second conductive part 2224 to electrically connect with a converging component whose material is different from that of the first pole part 2211. Furthermore, the use of composite materials can reduce the weight and cost of the conductive component 222, thereby reducing the weight and cost of the top cover assembly and the battery.

[0168] In some specific examples, the first pole portion 2211 with a negative polarity includes a first pole portion and a second pole portion, the first pole portion is welded to the first conductive portion 2223, the second pole portion is matched with and electrically connected to the first pole portion, the first pole portion and the first conductive portion 2223 are made of aluminum, and the second pole portion and the second conductive portion 2224 are made of copper. That is, the first pole portion 2211 as the negative pole is also made of a composite material, and the weight and cost of the first pole portion 2211 are reduced by matching the first pole portion and the second pole portion. In the case where the first pole portion 2211 includes a pole sink 22111 and a first annular protrusion 22112, the first pole portion can be the first annular protrusion 22112, and the corresponding second pole portion is the pole sink 22111.

[0169] Exemplarily, when the first pole portion 2211 includes a pole sink 22111 and a first annular protrusion 22112, when the pole terminal 22 is a negative pole terminal, the pole 221 and the conductive component 222 of the pole terminal 22 are made of copper-aluminum composite materials. The first conductive portion 2223 of the conductive component 222 is provided with a welding sink 2221 and a contact surface 2225, and the second conductive portion 2224 is provided with a first sealing ring groove 2222, a bottom surface and an assembly surface 2226. The pole 221 is made of a copper-aluminum composite material, and is provided with a first annular protrusion 22112, a pole sink 22111 and a welding surface 206. The inner wall surface of the first annular protrusion 22112 is assembled with the contact surface 2225 of the first conductive part 2223 and the assembly surface 2226 of the second conductive part 2224, and the welding sink 2221 of the first conductive part 2223 and the first annular protrusion 22112 are welded and fixed. The first annular protrusion 22112 and the first conductive part 2223 are made of the same material, such as aluminum. Through the welding of aluminum and aluminum, the fluidity is good and cracks are not easy to occur, which is conducive to improving the sealing effect of the welding. The first sealing ring groove 2222 of the second conductive part 2224 contacts the first sealing ring for overpressure. The pole ear 112 is arranged between the bottom surface of the second conductive part 2224 and the welding surface 206 of the pole 221. The second conductive part 2224 and the welding surface 206 are made of the same material. The second pole part 2212 is preferably made of copper.

[0170] The above embodiments illustrate that the conductive component 222 can be made of composite materials. In other embodiments, see Figure 25a-Figure 25b and Fig.26 The conductive component 222 as a whole can also be made of the same material. Specifically, the conductive component 222 as a whole is made of the same material as the first pole portion 2211. Exemplarily, the conductive component 222 as a whole and the first pole portion 2211 are both made of aluminum.

[0171] In some embodiments, the entire material of the positive pole terminal 22 is aluminum. Exemplarily, when the pole terminal 22 is a positive pole terminal, the materials of the first pole portion 2211, the conductive component 222, and the second pole portion 2212 of the pole terminal 22 are all aluminum. This ensures reliable electrical connection between different pole terminals 22 and corresponding pole ears 112, while ensuring welding yield.

[0172] In some embodiments, the top cover assembly 2 includes a plurality of pole terminals 22, and at least two of the plurality of pole terminals 22 have different polarities. That is, the top cover assembly 2 is provided with a plurality of pole terminals 22, and at least one pole terminal 22 is a negative pole terminal, and at least one pole terminal 22 is a positive pole terminal, so as to meet the corresponding battery function requirements.

[0173] In an embodiment, the width of the tab through hole 207 is not less than 0.2 mm to allow the tab 112 to pass smoothly and reduce the output weight. Preferably, the width of the tab through hole 207 ranges from 0.3 to 5 mm. Exemplarily, the width of the tab through hole 207 is 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm.

[0174] In some embodiments, the top cover assembly 2 further includes a first plastic part 24 and a second plastic part 25, wherein the first plastic part 24 is located between the top cover plate 21 and the pole terminal 22, and the second plastic part 25 is disposed between the top cover plate 21 and the battery cell assembly to meet the electrical performance of the battery.

[0175] In some embodiments, an explosion-proof valve 26 and an explosion-proof valve film 27 are provided on the top cover plate 21 to achieve pressure relief and exhaust.

[0176] The battery can be a single-cell battery, such as Fig.27a and Figure 27b The above-mentioned battery may also be a multi-cell battery such as a dual-cell, triple-cell, quad-cell, etc. Fig.28a and Fig.28b described.

[0177] The present application also provides an electric device, which includes any one of the batteries in the above embodiments. Since the electric device uses the battery in the above embodiments, please refer to the above embodiments for the beneficial effects of the electric device.

[0178] It is understandable that the design of the electrical device can be energy storage application or power output, or the two application modes can be compatible, which should all fall within the scope of the description of this application, specifically including but not limited to mobile phones, tablet computers, laptops, etc.

[0179] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0180] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery, characterized in that: include: The housing (3) is provided with a receiving cavity (31); A cell assembly (1) is arranged in the accommodating cavity (31), the cell assembly (1) comprising a cell body (111) and a pole lug (112), the pole lug (112) comprising a connecting portion (1121), a transition portion (1122) and a welding portion (1123) welded together, the transition portion (1122) being arranged between the connecting portion (1121) and the welding portion (1123), the connecting portion (1121) being electrically connected to the cell body (111); the welding portion (1123) comprising a base layer (11231) and a welding tooth surface (11232) and a flat tooth surface (11233) respectively arranged on both sides of the base layer (11231), the welding tooth surface (11232) being provided with a plurality of tooth holes (11234), and the flat tooth surface (11233) being provided with a plurality of tooth surface protrusions (11235); A top cover assembly (2) comprises a top cover plate (21) and a pole terminal (22), wherein the top cover plate (21) is arranged at the mouth (32) of the accommodating cavity (31), the pole terminal (22) is arranged on the top cover plate (21), the pole terminal (22) is provided with a welding surface (206), and the welding tooth surface (11232) contacts the welding surface (206) and is welded to form a weld bead (204).

2. The battery according to claim 1, characterized in that The height of the tooth surface protrusion (11235) is smaller than the depth of the tooth hole (11234).

3. The battery according to claim 2, characterized in that The thickness T of the welding portion (1123), the depth T1 of the tooth hole (11234), and the height T2 of the tooth surface protrusion (11235) satisfy the following relationship: 0≤T2<T1≤T≤10mm; 0≤T1≤3mm; 0≤T2≤2mm.

4. The battery according to claim 1, characterized in that The plurality of tooth holes (11234) are distributed in an array on the welding tooth surface (11232).

5. The battery according to claim 1, characterized in that The weld width W of the weld bead (204) formed by welding the weld portion (1123) and the weld surface (206) is 焊 and penetration T 焊 , satisfying the following relationship: 0.3mm≤W 焊 ≤5.0mm; and / or, 0.3mm≤T 焊 ≤10mm.

6. The battery according to claim 1, characterized in that The length L2 and width W2 of the weld mark on the flat tooth surface (11233), and the length L1 and width W1 of the weld bead (204) formed by welding the welding portion (1123) and the welding surface (206) satisfy the following relationship: L1 / L2≤1; nW1 / W2≤1; In the formula, n is the number of the weld beads (204) on the welding surface (206).

7. The battery according to claim 1, characterized in that The ratio of the area S1 of the welding portion (1123) to the area S2 of the welding surface (206) is in the range of 0.4 to 0.9; and / or, The ratio of the width W of the welding portion (1123) to the width W3 of the welding surface (206) is in the range of 0.5 to 0.

98.

8. The battery according to any one of claims 1 to 7, characterized in that: The pole terminal (22) comprises: A pole (221) is provided on the top cover plate (21), and the pole (221) is provided with a pole ear through hole (207); An electrically conductive component (222) is provided on the pole (221), and a pole tab gap (208) communicating with the pole tab through hole (207) is formed between the electrically conductive component (222) and the pole (221); The welding surface (206) is provided on the wall surface of the pole (221) facing the pole tab gap (208), and the transition portion (1122) is provided in the pole tab through hole (207) so that the welding portion (1123) is welded to the welding surface (206).

9. The battery according to claim 8, characterized in that The pole (221) comprises a pole sink (22111) and a first annular protrusion (22112) provided at one end of the pole sink (22111) facing the conductive component (222), and the pole ear through hole (207) and the welding surface (206) are both provided on the pole sink (22111).

10. The battery according to claim 9, characterized in that The conductive component (222) is welded to the pole (221), and the formed first weld (201) is annular, and the projection of the area surrounded by the first weld (201) on the plane where the top cover plate (21) is located covers the projection of the pole ear through hole (207) on the plane where the top cover plate (21) is located; The pole terminal (22) further comprises a first seal (223), the first seal (23) being ring-shaped, the first seal (223) being arranged between the conductive component (222) and the pole (221), and the projection of the area surrounded by the first seal (223) on the plane where the top cover plate (21) is located covers the projection of the pole ear through hole (207) on the plane where the top cover plate (21) is located.

11. The battery according to claim 10, characterized in that A pole sink groove (22113) is formed between the pole sink platform (22111) and the first annular protrusion (22112); the conductive component (222) is arranged in the pole sink groove (22113); the outer edge of the conductive component (222) is welded to the pole (221); and the first sealing component (223) is arranged on the inner side of the first welding seam (201).

12. The battery according to claim 10, characterized in that An annular welding sink (2221) is provided on the edge of the conductive component (222); the welding sink (2221) is flush with the top surface of the first annular protrusion (22112); and the welding sink (2221) and the first annular protrusion (22112) are welded at their joints.

13. The battery according to claim 10, characterized in that The first sealing member (23) is provided between the end surface of the conductive component (222) facing the pole sinking platform (22111) and the pole sinking platform (22111).

14. The battery according to claim 13, characterized in that The first sealing component (223) is a first sealing ring; A first sealing ring groove (2222) is provided on the end surface of the conductive component (222) facing the pole sink (22111), the first sealing ring is provided in the first sealing ring groove (2222), and the depth of the first sealing ring groove (2222) is less than the thickness of the first sealing ring; Alternatively, a second sealing ring groove is provided on the end surface of the pole sink (22111) facing the conductive component (222), the first sealing ring is provided in the second sealing ring groove, and the depth of the second sealing ring groove is less than the thickness of the first sealing ring.

15. The battery according to claim 10, characterized in that The pole (221) comprises: A first pole portion (2211), the conductive component (222) being welded to the first pole portion (2211), the first sealing member (223) being arranged between the conductive component (222) and the first pole portion (2211), and the pole ear through hole (207) and the welding surface (206) being arranged on the first pole portion (2211); The second pole portion (2212) is arranged at one end of the first pole portion (2211) away from the conductive component (222) and is sealed and fixedly connected to the first pole portion (2211). The second pole portion (2212) is sealed and connected to the top cover plate (21). The second pole portion (2212) is annular and the hollow portion is connected to the pole ear through hole (207).

16. The battery according to claim 15, characterized in that The second pole portion (2212) is welded to the first pole portion (2211).

17. The battery according to claim 15, characterized in that It also comprises a second annular sealing member (23), wherein the second sealing member (23) is arranged at the connection between the second pole portion (2212) and the top cover plate (21).

18. The battery according to claim 15, characterized in that The second pole portion (2212) comprises: The base body (22121) is annular, and the base body (22121) is sealedly connected to the top cover plate (21); A second annular protrusion (22122) is provided at one end of the base (22121) facing the first pole portion (2211); the second annular protrusion (22122) is welded to the first pole portion (2211), and together with the first pole portion (2211) forms a containing cavity (209) that is in communication with the pole ear through hole (207).

19. The battery according to claim 18, characterized in that The second annular protrusion (22122) comprises: A side wall (22122a) extending along a first direction, wherein the bottom end of the side wall (22122a) is arranged on the base (22121); An inner edge (22122b) extends along the second direction, the inner edge (22122b) is arranged at the top end of the side wall (22122a), and the inner edge (22122b) is welded to the first pole portion (2211).

20. The battery according to claim 19, characterized in that A boss (22114) is provided at one end of the first pole portion (2211) facing the second pole portion (2212); the boss (22114) is arranged inside the inner edge (22122b); the top surface of the inner edge (22122b) abuts against the first pole portion (2211); and the inner edge (22122b) and the boss (22114) are welded at their joints.

21. The battery according to claim 15, characterized in that The conductive component (222) comprises a first conductive part (2223) and a second conductive part (2224) made of different materials; the first conductive part (2223) is welded to the first pole part (2211); the second conductive part (2224) cooperates with and is electrically connected to the first conductive part (2223); and the material of the first conductive part (2223) is the same as that of the first pole part (2211).

22. The battery according to claim 21, characterized in that The first pole portion (2211) with a negative polarity comprises a first pole portion and a second pole portion, the first pole portion is welded to the first conductive portion (2223), the second pole portion is matched with and electrically connected to the first pole portion, the first pole portion and the first conductive portion (2223) are made of aluminum, and the second pole portion and the second conductive portion (2224) are made of copper.

23. The battery according to claim 15, characterized in that The entire material of the conductive component (222) is the same as that of the first pole portion (2211).

24. The battery according to claim 23, characterized in that The pole terminal (22) with positive polarity is entirely made of aluminum.

25. The battery according to claim 1, characterized in that It comprises a plurality of pole terminals (22), wherein at least two of the pole terminals (22) have different polarities.

26. The battery according to claim 1, characterized in that The battery cell assembly (1) further comprises a tab glue layer (12), wherein the tab glue layer (12) covers one end of the connecting portion (1121) facing the top cover assembly (2), and the tab glue layer (12) extends along the extension direction of the tab (112) at one end to contact the battery cell body (111), and extends at the other end to contact the transition portion (1122).

27. The battery according to claim 26, characterized in that The battery cell assembly (1) further comprises an insulating sheet (13), the insulating sheet (13) being provided with a avoidance groove (131), the transition portion (1122) being arranged in the avoidance groove (131), and a portion of the tab glue layer (12) being located between the connecting portion (1121) and the insulating sheet (13).

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