Battery cell, battery and assembly method

Abstract

The invention relates to a battery monomer, a battery and an assembling method, and belongs to the technical field of battery manufacturing. The battery cell includes: a case; the electrode assembly comprises a main body and a tab; a cover body; the two sides, in the thickness direction of the cover body, of the pole respectively comprise a first surface and a second surface, the first surface forms at least part of the side wall of a first groove, the second surface is sunken to form a second groove, the first groove is used for containing a tab and is in conductive connection with the tab, and the second groove is used for containing the tab. And the second groove is used for being electrically connected with an external busbar. The battery monomer is compact in structure and has relatively high energy density. The invention further provides a battery which comprises the battery monomer. The invention also provides an assembly method for assembling the battery cell.

Description

Technical Field

[0001] The present application relates to the technical field of battery manufacturing, and in particular to a battery cell, a battery, and an assembly method. Background Art

[0002] With the rapid development of the new energy field, lithium batteries have the advantages of high energy density, high voltage, and environmental protection. In recent years, they have gradually replaced the traditional energy industry. The manufacturing level has developed rapidly, and higher requirements have been put forward for energy density and reliability.

[0003] The pole is conductively connected to the pole lug inside the battery cell, and the busbar needs to be conductively connected to the pole to connect multiple battery cells in series or in parallel to form a battery module. However, during this assembly process, a certain amount of installation space is usually required, which reduces the structural compactness and energy density of the battery cell and battery module. Summary of the invention

[0004] To this end, the present application proposes a battery cell, a battery, and an assembly method, which can improve the energy density of the battery cell and the battery.

[0005] The battery cell of the first aspect embodiment of the present application includes: a shell body, which is provided with an opening; an electrode assembly, which is arranged inside the shell, and the electrode assembly includes a main body and a pole ear; a cover body, which is provided with a pole hole, and the cover body covers the opening to enclose the electrode assembly inside the shell; a pole, which is installed in the pole hole, and the pole includes a first surface and a second surface on both sides along the thickness direction of the cover body, respectively, the first surface is configured to form at least a part of the side wall of the first groove, and the second surface is recessed to form a second groove, the first groove is used to accommodate the pole ear and is conductively connected to the pole ear, and the second groove is used to be conductively connected to an external bus.

[0006] Optionally, the second groove forms a protrusion corresponding to the first surface, the first groove includes a first bottom wall and a first side wall, the first side wall forms a partial surface of the protrusion, and the second groove includes a second bottom wall and a second side wall; wherein, the first side wall is conductively connected to the pole ear, and the second side wall is used for conductive connection to an external bus, and along the normal direction of the second side wall, the projections of the first side wall and the second side wall are at least partially overlapped.

[0007] Optionally, the first groove extends continuously around the protrusion.

[0008] Optionally, the protrusion separates the first groove to form two sub-grooves that are not connected to each other, the pole lugs include two groups, each of the sub-grooves is used to accommodate a group of the pole lugs, and is conductively connected to a corresponding group of pole lugs.

[0009] Optionally, the battery cell further includes: an elastic member, at least partially disposed in the first groove, for pressing the tab into the first groove.

[0010] Optionally, the battery cell further includes: a contact finger assembly disposed inside the second groove, and the second groove is configured to be conductively connected to an external bus bar through the contact finger assembly.

[0011] Optionally, the second groove includes a second bottom wall and a second side wall, the second side wall extends around the second bottom wall, and the second side wall is conductively connected to the contact finger assembly.

[0012] Optionally, the pole includes a first part and a second part, the surface of the first part is configured as a partial side wall of the first groove, the second groove is formed in the first part, the second part is connected to the cover body, the first part and the second part are welded together, and the welding mark between the pole ear and the pole is formed on the first surface.

[0013] Optionally, the battery cell further includes: a first insulating member, the pole is installed in the pole hole through the first insulating member, the outer side of the pole is provided with a first limiting portion, the first insulating member is provided with a second limiting portion, and the first limiting portion and the second limiting portion are matched in a concave-convex manner.

[0014] The battery of the second aspect embodiment of the present application includes: a plurality of battery cells as described in the first aspect embodiment of the present application; a busbar for electrically connecting at least two battery cells, including a conductive protrusion, which is inserted into the second groove to achieve conductive connection between the battery cells and the busbar.

[0015] The assembly method of the battery cell of the third embodiment of the present application is used for the battery cell of the first embodiment of the present application, comprising:

[0016] The electrode ear is arranged inside the first groove;

[0017] Welding the pole lug to the pole;

[0018] Welding the shell and the cover together;

[0019] The conductive protrusion of the busbar is inserted into the second groove to achieve conductive connection between the battery cell and the busbar.

[0020] Optionally, the “welding the pole lug to the pole” includes:

[0021] The pole column is connected to the pole lug by welding from one side of the second surface.

[0022] Optionally, the pole includes a first portion and a second portion, the first portion is configured as a partial side wall of the first groove, the second groove is formed in the first portion, and the “welding the pole lug to the pole” includes:

[0023] Welding the first portion to the tab from one side of the first surface;

[0024] connecting the second part to the cover body;

[0025] The cover body covers the opening of the shell, and the first part is connected with the second part by welding.

[0026] Optionally, the battery cell further includes a contact finger assembly, and the step of “inserting the conductive protrusion into the second groove” includes:

[0027] Disposing the finger assembly inside the second groove;

[0028] The conductive protrusion is inserted into the contact finger assembly, and the inner wall of the second groove is conductively connected to the bus bar through the contact finger assembly.

[0029] Compared with the prior art, this solution has the following beneficial effects:

[0030] The pole of the battery cell in the embodiment of the present application accommodates the pole lug through the first groove and is conductively connected to the pole lug, and the second groove is conductively connected to the bus. Since the first groove provides space for accommodating the pole lug, the battery cell and the battery structure are compact and have a higher energy density.

[0031] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0034] Figure 2 A cross-sectional view of a battery cell provided in an embodiment of the present application;

[0035] Figure 3 for Figure 2A partial enlarged view of the middle A;

[0036] Figure 4 A cross-sectional view of a first type of pole of a battery cell provided in an embodiment of the present application;

[0037] Figure 5 A schematic diagram of the structure of a second type of pole of a battery cell provided in an embodiment of the present application;

[0038] Figure 6 A schematic diagram of the structure of a third type of pole of a battery cell provided in an embodiment of the present application;

[0039] Figure 7 A schematic structural diagram of a fourth type of pole of a battery cell provided in an embodiment of the present application;

[0040] Figure 8 A schematic diagram of a welding process related to a fourth type of pole of a battery cell provided in an embodiment of the present application;

[0041] Fig. 9 A schematic diagram of the structure of a battery provided in an embodiment of the present application.

[0042] Icon: 100-battery cell; 110-housing; 120-cover; 121-pole hole; 130-electrode assembly; 131-body; 132-ear; 140-pole; 141-first groove; 1411-first bottom wall; 1412-first side wall; 1413-third side wall; 142-second groove; 1421-second bottom wall; 1422-second side wall; 1423-long side wall; 1424-short side wall ;1425-sub-groove;143-first surface;144-second surface;145-protrusion;146-first part;147-second part;1471-mounting hole;148-first limiting part;150-contact finger assembly;160-elastic member;170-first insulating member;171-second limiting part;180-elastic member;200-battery;210-bus;211-conductive protrusion;212-plate body. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0045] like Figure 1 , Figure 2 and Figure 3 As shown, the battery cell 100 of some embodiments of the present application includes a shell 110, a cover 120, an electrode assembly 130 and a pole 140. The shell 110 is provided with an opening, the cover 120 is provided with a pole hole 121, and the cover 120 covers the opening to seal the electrode assembly 130 inside the shell 110; the electrode assembly 130 is arranged inside the shell 110, and the electrode assembly 130 includes a main body 131 and a pole ear 132. The pole 140 is installed in the pole hole 121, and the two sides of the pole 140 along the thickness direction of the cover 120 respectively include a first surface 143 and a second surface 144, the first surface 143 is configured as at least part of the side wall of the first groove 141, and the second surface 144 is recessed to form a second groove 142, the first groove 141 is used to accommodate the pole ear 132, and is conductively connected to the pole ear 132, and the second groove 142 is used to conductively connect to the external bus 210.

[0046] The thickness direction of the pole 140 extends along the direction Z. The first surface 143 and the second surface 144 are respectively disposed on opposite sides of the pole 140 along the direction Z. The first surface 143 and the second surface 144 are parallel to the XY plane.

[0047] The first groove 141 includes a first bottom wall 1411 and a first side wall 1412, and the first surface 143 can be constructed as the first bottom wall 1411 and the first side wall 1412; the first surface 143 can also be constructed as only the first bottom wall 1411, and the pole 132 is recessed into the surface of the cover body 120 on one side of the first surface 143, and the hole wall of the pole hole 121 is constructed as the first side wall 1412, and the cover body 120 and the pole 140 jointly form the first groove 141.

[0048] When the first surface 143 is recessed to form the first groove 141, the first surface 143 is recessed along direction Z to form the first groove 141, and the second surface 144 is recessed along direction Z to form the second groove 142; the first surface 143 and the second surface 144 may also be recessed along other directions inclined to direction Z to form corresponding groove structures.

[0049] The pole 140 of the battery cell 100 of the embodiment of the present application accommodates the pole lug 132 through the first groove 141 and is conductively connected to the pole lug 132, and the second groove 142 is conductively connected to the bus 210. Since the first groove 141 provides a space for accommodating the pole lug 132, the battery cell 100 has a compact structure and a high energy density.

[0050] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the second groove 142 forms a protrusion 145 corresponding to the first surface 143, the first groove 141 includes a first bottom wall 1411 and a first side wall 1412, the first side wall 1412 forms a partial surface of the protrusion 145, and the second groove 142 includes a second bottom wall 1421 and a second side wall 1422; wherein the first side wall 1412 is conductively connected to the pole ear 132, and the second side wall 1422 is used for conductive connection to the external bus 210, and along the normal direction of the second side wall 1422, the projections of the first side wall 1412 and the second side wall 1422 are at least partially overlapped.

[0051] The first side wall 1412 forms the outer peripheral wall of the protrusion 145, and the second surface 144 is recessed along the direction Z to form a second groove 1422, and the normal of the second groove 1422 extends along a direction perpendicular to the direction Z; for example, the second groove 1422 is a cylindrical groove, and the normal of the second side wall 1422 is the radial direction of the cylindrical groove; for another example, the second groove 1422 is a square groove, and the normal of the second side wall 1422 is the normal of each side wall of the square groove.

[0052] like Figure 4 As shown, the first groove 141 further includes a third side wall 1413 , the third side wall 1413 is connected to the first bottom wall 1411 , the third side wall 1413 is arranged opposite to the first side wall 1412 , and the third side wall 1413 extends around the protrusion 145 .

[0053] With this arrangement, the current flows out from the pole ear 132 and can flow directly from the first side wall 1412 to the second side wall 1422 , which greatly shortens the current path and increases the current area, thereby reducing the resistance of the battery cell 100 and improving the fast charging performance of the battery cell 100 .

[0054] In some other embodiments of the present application, the first bottom wall 1411 may also be in conductive contact with the pole ear 132 to improve the conductivity of the pole ear 132 and the pole 140; the second surface 144 may also be in conductive contact with the plate body 212 of the bus 210 to improve the conductivity of the bus 210 and the pole 140; the second bottom wall 1421 may also be conductively connected to the bottom surface of the conductive protrusion 211 of the bus 210.

[0055] like Figure 3As shown, in some embodiments of the present application, the battery cell 100 further includes a contact finger assembly 150 disposed inside the second groove 142 , and the second groove 142 is configured to be conductively connected to an external bus bar 210 through the contact finger assembly 150 .

[0056] By providing the contact finger assembly 150, the contact pressure between the second groove 142 and the conductive protrusion 211 of the external bus 210 can be increased, thereby improving the conductive performance of the pole 140 and the conductive protrusion 211. The use of the contact finger assembly 150 can ensure that the pole 140 and the bus 210 have stable current flow capacity while being detachable, which is convenient for replacing structural parts.

[0057] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the second groove 142 includes a second bottom wall 1421 and a second side wall 1422 . The second side wall 1422 extends around the second bottom wall 1421 , and the second side wall 1422 is conductively connected to the contact finger assembly 150 .

[0058] As an example, Figure 4 As shown, the second groove 142 is of a long and narrow structure, and the second side wall 1422 includes two oppositely disposed long side walls 1423 and two oppositely disposed short side walls 1424 . At least the two long side walls 1423 are used for conductive connection with the contact finger assembly 150 .

[0059] With this arrangement, the second side wall 1422 is conductively connected to the conductive protrusion 211 of the bus 210 through the contact finger assembly 150 . The contact finger assembly 150 as a conductive member increases the contact pressure and release point, thereby improving the conductive performance of the pole 140 and the conductive protrusion 211 .

[0060] like Figure 5 As shown, in some embodiments of the present application, the first groove 141 extends continuously around the protrusion 145 .

[0061] That is, the first side wall 1412 serves as the outer peripheral wall of the protrusion 145 and is a closed annular structure, and the first groove 141 is a closed annular groove extending around the protrusion 145 .

[0062] Through this arrangement, the accommodation space of the first groove 141 can be increased, so as to fully accommodate the tab 132 , thereby improving the compactness and energy density of the battery cell 100 .

[0063] like Figure 6 As shown, in other embodiments of the present application, the protrusion 145 separates the first groove 141 to form two sub-grooves 1425 that are not connected to each other, and the pole ears 132 include two groups, each sub-groove 1425 is used to accommodate a group of pole ears 132 and is conductively connected to the corresponding group of pole ears 132.

[0064] Through this arrangement, each group of pole lugs 132 corresponds to one sub-groove 1425 , thereby simplifying the assembly process of the pole lugs 132 and the poles 140 .

[0065] like Figure 7 and Figure 8 As shown, in some embodiments of the present application, the pole 140 includes a first part 146 and a second part 147, the surface of the first part 146 is configured as a partial side wall of the first groove 141, the second groove 142 is formed in the first part 146, the second part 147 is connected to the cover body 120, the first part 146 and the second part 147 are welded together, and the welding mark between the pole ear 132 and the pole 140 is formed on the first surface 143.

[0066] It can be understood that the welding mark between the pole ear 132 and the pole 140 refers to the mark formed from one side of the welding head by the welding process.

[0067] The first side wall 1412 of the first groove 141 is formed in the first portion 146 , part of the first bottom wall 1411 is formed in the first portion 146 , and the third side wall 1413 is formed in the second portion 147 ; the bottom wall of the first portion 146 may also be configured to form the first bottom wall 1411 of the first groove 141 .

[0068] The outer wall of the first portion 146 is connected to the hole wall of the mounting hole 1471 by welding, and the second portion 147 is insulated and connected to the cover body 120 via the first insulating member 170 described below.

[0069] Through this arrangement, the pole 140 and the pole lug 132 can be welded from the first surface 143 of the pole 140, and a weld mark is formed on the first surface 143. Since the pole lug 132 of the electrode assembly 130 needs to be flattened in the first groove 141 before welding during welding, the first portion 146 only includes a part of the side wall of the first groove 141, thereby reducing the difficulty of flattening the pole lug 132 in the first groove 141, and can achieve welding from one side of the pole lug 132, thereby ensuring the welding quality of the pole lug 132 and the pole 140.

[0070] In other embodiments of the present application, the pole 140 may also be an integral structure.

[0071] With this arrangement, after the tabs 132 and the poles 140 are stacked, penetration welding can be performed from the outside of the cover 120 , and then the cover 120 and the shell 110 are covered to complete the assembly process of the battery cell 100 .

[0072] like Figure 7As shown, in some embodiments of the present application, the battery cell 100 also includes a first insulating member 170, the pole 140 is installed in the pole hole 121 through the first insulating member 170, the outer side of the pole 140 is provided with a first limiting portion 148, the first insulating member 170 is provided with a second limiting portion 171, and the first limiting portion 148 and the second limiting portion 171 are matched in a concave and convex manner.

[0073] The first limiting portion 148 is a groove structure, and the second limiting portion 171 is a protrusion structure. When the first insulating member 170 and the pole 140 are assembled along the direction Z, the first limiting portion 148 and the second limiting portion 171 are laterally engaged. In the circumferential direction of the pole 140, the first limiting portion 148 can extend continuously along the outer side surface of the pole 140, or can be arranged at multiple points; the second limiting portion 171 is arranged one-to-one with the first limiting portion 148.

[0074] This arrangement can improve the assembly firmness of the first insulating member 170 and the pole 140 , and reduce the risk of the pole 140 detaching from the first insulating member 170 .

[0075] like Figure 7 As shown, in some embodiments of the present application, the battery cell 100 further includes an elastic member 180 , and the elastic member 180 is at least partially disposed in the first groove 141 for pressing the tab 132 tightly against the first groove 141 .

[0076] The elastic member 180 can be completely disposed in the first groove 141, or partially extended into the first groove 141; the elastic member 180 can press the pole ear 132 against the first side wall 1412 of the first groove 141, or simultaneously press against the first bottom wall 1411 and the first side wall 1412; the elastic member 180 can be a spring, or an insulating patch. For example, the elastic member 180 is an insulating patch, the pole ear 132 is curled and accommodated in the first groove 141, the insulating patch is attached to the inner side of the curled shape of the pole ear 132, the outer side of the curled shape of the pole ear 132 contacts the first groove 141, and the insulating patch stretches the pole ear 132 from the inner side to press the pole ear 132 against the first groove 141.

[0077] With this arrangement, the tab 132 is pressed against the first groove 141 by the elastic member 180 , so that the first groove 141 and the tab 132 have sufficient contact pressure, thereby achieving reliable conductive connection between the tab 132 and the pole 140 .

[0078] Based on the implementation of “the pole 140 is an integral structure”, the pole lug 132 is flattened inside the first groove 141 by the elastic member 180 , and penetration welding is performed from the second surface 144 side, thereby improving the welding quality between the pole lug 132 and the pole 140 .

[0079] like Figure 1 , Figure 3 and Fig. 9 As shown, the battery 200 of some embodiments of the present application includes a bus 210 and a plurality of battery cells 100 . The bus 210 is used to electrically connect at least two battery cells 100 , and includes a conductive protrusion 211 . The conductive protrusion 211 is inserted into the second groove 142 to achieve conductive connection between the battery cell 100 and the bus 210 .

[0080] Due to the characteristics of the battery cell 100 of the embodiment of the present application, the battery 200 of the embodiment of the present application also has good structural compactness and improved energy density.

[0081] The battery cell assembly method of some embodiments of the present application is used to assemble a battery cell 100. The assembly method includes:

[0082] S100: placing the electrode tab 132 inside the first groove 141;

[0083] S200: welding the pole lug 132 to the pole post 140;

[0084] S300: welding the housing 110 and the cover 120 together;

[0085] S400 : inserting the conductive protrusion 211 of the busbar 210 into the second groove 142 to achieve conductive connection between the battery cell 100 and the busbar 210 .

[0086] The battery cell 100 of the embodiment of the present application is assembled using the assembly method of the embodiment of the present application. Since the tab 132 is disposed inside the first groove 141 , the battery cell 100 has a compact structure and a high energy density.

[0087] In some embodiments of the present application, S200: welding the pole lug 132 to the pole 140, including:

[0088] S210 : welding the pole 140 to the pole ear 132 from the second surface 144 side.

[0089] By the above method, after the tabs 132 and the poles 140 are stacked, penetration welding can be performed from the outside of the cover 120 , and then the cover 120 and the shell 110 are covered to complete the assembly process of the battery cell 100 .

[0090] In some other embodiments of the present application, the pole 140 includes a first portion 146 and a second portion 147, the first portion 146 is configured as a partial side wall of the first groove 141, and the second groove 142 is formed in the first portion 146. S200: Welding the pole lug 132 to the pole 140, including:

[0091] S220: welding the first portion 146 to the tab 132 from one side of the first surface 143;

[0092] S230: Connect the second portion 147 to the cover body 120;

[0093] S240 : Cover the opening of the shell 110 with the cover body 120 , and weld the first part 146 and the second part 147 together.

[0094] Since the pole tab 132 is curled and accommodated in the first groove 141, it is more difficult for the welding head to enter the first groove 141 to weld from one side of the pole tab 132. The conventional process usually performs welding from one side of the pole tab 132 to ensure the conductivity and connection strength of the pole tab 132 and the pole 140.

[0095] By means of the above method, the pole 140 is divided into a first part 146 and a second part 147, wherein the first part 146 is configured as a partial side wall of the first groove 141 rather than the complete first groove 141, so that during the welding process of the pole lug 132, there is sufficient space in the partial first groove 141 for flattening, thereby allowing welding operations to be performed from one side of the pole lug 132, thereby ensuring the welding quality between the pole lug 132 and the pole 140.

[0096] In some embodiments of the present application, the battery cell 100 further includes a contact finger assembly 150, S400: inserting the conductive protrusion 211 into the second groove 142, including:

[0097] S410: Disposing the finger assembly 150 inside the second groove 142;

[0098] S420 : inserting the conductive protrusion 211 into the contact finger assembly 150 , and the inner wall of the second groove 142 is conductively connected to the bus bar 210 through the contact finger assembly 150 .

[0099] The above method can complete the assembly process of the contact finger assembly 150 , and the contact finger assembly 150 can increase the contact pressure between the second groove 142 and the conductive protrusion 211 of the external bus 210 , thereby improving the conductive performance of the pole 140 and the conductive protrusion 211 .

[0100] The battery cell 100 of the embodiment of the present application is not only compact in structure and has a high energy density, but also can fully consider the welding process of the pole lug 132 and the pole 140 , thereby improving the manufacturing process level and improving the assembly cost-effectiveness and efficiency of the battery cell 100 .

[0101] It should be noted that, in the absence of conflict, the features in the embodiments of this application may be combined with each other.

[0102] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell (100), characterized in that: include: A housing (110) having an opening; An electrode assembly (130) is arranged inside the housing (110), and the electrode assembly (130) comprises a main body (131) and a tab (132); A cover body (120) is provided with a pole hole (121), and the cover body (120) covers the opening to seal the electrode assembly (130) inside the shell (110); A pole (140) is installed in the pole hole (121), and the pole (140) includes a first surface (143) and a second surface (144) on both sides along the thickness direction of the cover body (120), respectively, the first surface (143) is configured to form at least a part of the side wall of the first groove (141), and the second surface (144) is recessed to form a second groove (142), the first groove (141) is used to accommodate the pole ear (132) and is conductively connected to the pole ear (132), and the second groove (142) is used to be conductively connected to an external bus bar.

2. The battery cell (100) according to claim 1, characterized in that: The second groove (142) forms a protrusion (145) corresponding to the first surface (143); the first groove (141) includes a first bottom wall (1411) and a first side wall (1412); the first side wall (1412) forms a partial surface of the protrusion (145); the second groove (142) includes a second bottom wall (1421) and a second side wall (1422); The first side wall (1412) is conductively connected to the pole ear (132), and the second side wall (1422) is used for conductively connecting to an external bus bar, and along the normal direction of the second side wall (1422), the projections of the first side wall (1412) and the second side wall (1422) are at least partially overlapped.

3. The battery cell (100) according to claim 2, characterized in that: The first groove (141) extends continuously around the protrusion (145).

4. The battery cell (100) according to claim 2, characterized in that: The protrusion (145) separates the first groove (141) to form two sub-grooves that are not connected to each other. The pole lugs (132) include two groups, and each of the sub-grooves is used to accommodate a group of the pole lugs (132) and is conductively connected to a corresponding group of pole lugs (132).

5. The battery cell (100) according to claim 1, characterized in that: Also includes: The elastic member is at least partially disposed in the first groove (141) and is used to press the pole lug (132) into the first groove (141).

6. The battery cell (100) according to claim 1, characterized in that: Also includes: The contact finger assembly (150) is arranged inside the second groove (142), and the second groove (142) is configured to be conductively connected to an external bus bar through the contact finger assembly (150).

7. The battery cell (100) according to claim 6, characterized in that: The second groove (142) comprises a second bottom wall (1421) and a second side wall (1422), wherein the second side wall (1422) extends around the second bottom wall (1421), and the second side wall (1422) is conductively connected to the contact finger assembly (150).

8. The battery cell (100) according to claim 1, characterized in that: The pole (140) comprises a first part (146) and a second part (147), the surface of the first part (146) being configured as a partial side wall of the first groove (141), the second groove (142) being formed in the first part (146), the second part (147) being connected to the cover body (120), the first part (146) and the second part (147) being welded to each other, and the welding mark between the pole ear (132) and the pole (140) being formed on the first surface (143).

9. The battery cell (100) according to claim 1, characterized in that: Also includes: A first insulating member (170), the pole (140) is installed in the pole hole (121) through the first insulating member (170), the outer side surface of the pole (140) is provided with a first limiting portion (148), the first insulating member (170) is provided with a second limiting portion (171), and the first limiting portion (148) and the second limiting portion (171) are matched in a concave-convex manner.

10. A battery (200), characterized in that: include: A plurality of battery cells (100) according to any one of claims 1 to 9; The busbar (210) is used to electrically connect at least two battery cells, and comprises a conductive protrusion (211), wherein the conductive protrusion (211) is inserted into the second groove (142) to achieve conductive connection between the battery cell (100) and the busbar (210).

11. A method for assembling a battery cell, for assembling a battery cell (100) according to any one of claims 1 to 9, characterized in that: include: The pole lug (132) is arranged inside the first groove (141); The pole lug (132) is connected to the pole column (140) by welding; The shell (110) and the cover (120) are connected by welding; The conductive protrusion (211) of the busbar (210) is inserted into the second groove (142) to achieve conductive connection between the battery cell (100) and the busbar (210).

12. The assembly method according to claim 11, characterized in that: The step of “welding the pole lug (132) and the pole column (140)” includes: The pole (140) is connected to the pole ear (132) by welding from one side of the second surface (144).

13. The assembly method according to claim 11, characterized in that: The pole (140) comprises a first portion (146) and a second portion (147), the first portion (146) being configured as a partial side wall of the first groove (141), the second groove (142) being formed in the first portion (146), and the step of “welding the pole lug (132) to the pole (140)” comprises: Welding the first portion (146) to the pole lug (132) from one side of the first surface (143); Connecting the second portion (147) to the cover body (120); The cover body (120) covers the opening of the shell (110), and the first part (146) and the second part (147) are connected by welding.

14. The assembly method according to claim 11, characterized in that: The battery cell (100) further comprises a contact finger assembly (150), and the step of "inserting the conductive protrusion (211) into the second groove (142)" comprises: Disposing the contact finger assembly (150) inside the second groove (142); The conductive protrusion (211) is inserted into the contact finger assembly (150), and the inner wall of the second groove (142) is conductively connected to the bus bar (210) through the contact finger assembly (150).

Images