Pole structure, pole structure preparation method, top cover assembly and battery

Abstract

The invention provides a pole structure, a pole structure preparation method, a top cover assembly and a battery, the pole structure comprises a pole and an electrode leading-out terminal, the pole comprises a first connecting end and a second connecting end which are opposite to each other, and the first connecting end is used for being connected with a tab of the battery; the electrode leading-out terminal is in welded connection with the second connecting end of the pole, and a welding area is formed at the joint of the electrode leading-out terminal and the pole; wherein the pole comprises a first welding part located in the welding area, the electrode leading-out terminal comprises a second welding part located in the welding area, and the first welding part wraps at least part of the second welding part; and / or the second welding part wraps at least part of the first welding part. According to the embodiment of the invention, the first welding part wraps at least part of the second welding part, or the second welding part wraps at least part of the first welding part. Therefore, the connecting strength of the electrode leading-out terminal and the second connecting end of the pole can be improved, and the technical problem that the connecting position of the pole and the electrode leading-out terminal is broken is solved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a pole structure, a method for preparing the pole structure, a top cover assembly and a battery. Background Art

[0002] In the related art, the battery cell is connected to one end of the pole through the pole ear, the other end of the pole is connected to the electrode lead terminal, and the electrode lead terminal is connected to the bus bar, so as to realize the series and parallel connection between multiple batteries. However, the connection strength between the pole and the electrode lead terminal is insufficient, and the connection between the pole and the electrode lead terminal is prone to breakage. Summary of the invention

[0003] The embodiments of the present application provide a pole structure, a pole structure preparation method, a top cover assembly and a battery, which can improve the technical problem that the connection strength between the pole and the electrode lead terminal of the pole structure is insufficient, and the connection between the pole and the electrode lead terminal is prone to breakage.

[0004] In a first aspect, an embodiment of the present application provides a pole structure, the pole structure comprising:

[0005] A pole, comprising a first connecting end and a second connecting end opposite to each other, wherein the first connecting end is used to be connected to a pole lug of a battery;

[0006] An electrode lead terminal is welded to the second connection end of the pole, and a welding area is formed at the connection between the electrode lead terminal and the pole;

[0007] The pole includes a first welding portion located in the welding area, the electrode lead terminal includes a second welding portion located in the welding area, the first welding portion wraps at least a portion of the second welding portion; and / or the second welding portion wraps at least a portion of the first welding portion.

[0008] In one embodiment, the first welding part and the second welding part are interlocked and diffusely composited, so that the first welding part wraps at least a portion of the second welding part; and / or the second welding part wraps at least a portion of the first welding part.

[0009] In some embodiments, the welding area is formed by solidifying a molten pool formed by heating a connection between the electrode lead terminal and the electrode column.

[0010] In some embodiments, the first welding portion is formed with a first connecting groove, the second welding portion includes a first embedding portion, and the first embedding portion is embedded in the first connecting groove; and / or,

[0011] The second welding portion is formed with a second connecting groove, and the first welding portion includes a second embedding portion, and the second embedding portion is embedded in the second connecting groove.

[0012] In some embodiments, the first engaging portion includes a first engaging body, and a plurality of first branches protruding from the first engaging body; and / or,

[0013] The second engaging portion includes a second engaging body and a plurality of second branches protruding from the second engaging body.

[0014] In some embodiments, the hardness and / or density of the pole is greater than the hardness and / or density of the electrode lead terminal; or,

[0015] The hardness and / or density of the pole is smaller than the hardness and / or density of the electrode lead terminal.

[0016] In some embodiments, the first welding portion accounts for greater than or equal to 20% of the volume of the welding area, and the second welding portion accounts for greater than or equal to 30% of the volume of the welding area.

[0017] In some embodiments, the welding region extends along the circumference of the pole.

[0018] In some embodiments, the material of the pole includes copper, and the material of the electrode lead terminal includes aluminum.

[0019] In some embodiments, the pole is an integrated structure, and the pole is made of metal; and / or,

[0020] The electrode lead terminal is an integrated structure, and the material of the electrode lead terminal is metal.

[0021] In some embodiments, the depth of the welding area is greater than or equal to 0.5 mm; the width of the welding area is greater than or equal to 1 mm.

[0022] In some embodiments, the penetration depth of the first weld portion is less than the penetration depth of the second weld portion.

[0023] In some embodiments, the penetration depth of the first weld portion is greater than or equal to 0.3 mm; the penetration depth of the second weld portion is greater than or equal to 0.5 mm.

[0024] In a second aspect, an embodiment of the present application provides a method for preparing a pole structure, the method comprising:

[0025] Providing a pole, the pole comprising a first connecting end and a second connecting end opposite to each other, the first connecting end being used for connecting to a pole lug of a battery;

[0026] Providing electrode lead terminals;

[0027] The electrode lead terminal is welded to the second connection end of the pole to form a welding area at the connection between the electrode lead terminal and the pole, so that the first welding portion of the pole located in the welding area wraps at least a portion of the second welding portion of the electrode lead terminal located in the welding area, and / or the second welding portion of the electrode lead terminal located in the welding area wraps at least a portion of the first welding portion of the pole located in the welding area.

[0028] In some embodiments, the step of welding the electrode lead terminal to the second connection end of the pole to form a welding area includes:

[0029] forming a laser welding spot at a connection between the second connection end and the electrode lead terminal;

[0030] The laser welding spot is controlled to move along a moving trajectory while swinging along a swinging trajectory in a direction intersecting the moving trajectory, so as to weld the electrode lead terminal to the second connecting end of the pole to form a welding area; wherein the moving trajectory extends along the circumference of the pole and is located on the surface of the electrode lead terminal or the surface of the second connecting end; and the swinging trajectory intersects the connection between the second connecting end and the electrode lead terminal.

[0031] In some embodiments, the laser welding spot includes an annular melting spot and an annular preheating spot, the power of the annular melting spot is greater than the power of the annular preheating spot, and the annular preheating spot and the annular melting spot are distributed in sequence along the moving direction of the laser welding spot;

[0032] The swing track includes a first annular track and a second annular track respectively intersecting with the connection between the second connection end and the electrode lead terminal, the annular preheating spot swings along the first annular track, and the annular melting spot swings along the second annular track.

[0033] In some embodiments, a ratio of the power of the annular melting spot to the power of the annular preheating spot is greater than or equal to 110% and less than or equal to 130%.

[0034] In a third aspect, an embodiment of the present application provides a top cover assembly, comprising:

[0035] A top cover sheet having a penetrating mounting hole;

[0036] A pole structure, wherein the pole structure is the pole structure as described above, or the pole structure is the pole structure obtained by the pole structure preparation method as described above, wherein the pole structure comprises a pole and an electrode lead terminal, wherein the pole comprises a first connection end and a second connection end opposite to each other, wherein the first connection end is used to connect to a pole ear of a battery; the electrode lead terminal is welded to the second connection end of the pole, and a welding area is formed at the connection between the electrode lead terminal and the pole; the pole comprises a first welding portion located in the welding area, and the electrode lead terminal comprises a second welding portion located in the welding area, wherein the first welding portion wraps at least a portion of the second welding portion; and / or the second welding portion wraps at least a portion of the first welding portion; the pole passes through the mounting hole, and the top cover sheet is located on one side of the electrode lead terminal along the direction from the second connection end to the first connection end;

[0037] The insulating sheet is clamped between the electrode lead terminal and the top cover sheet.

[0038] In a fourth aspect, an embodiment of the present application provides a battery, comprising the top cover assembly as described above, wherein the top cover assembly comprises:

[0039] A top cover sheet having a penetrating mounting hole;

[0040] A pole structure, wherein the pole structure is the pole structure as described above, or the pole structure is the pole structure obtained by the pole structure preparation method as described above, wherein the pole structure comprises a pole and an electrode lead terminal, wherein the pole comprises a first connection end and a second connection end opposite to each other, wherein the first connection end is used to connect to a pole ear of a battery; the electrode lead terminal is welded to the second connection end of the pole, and a welding area is formed at the connection between the electrode lead terminal and the pole; the pole comprises a first welding portion located in the welding area, and the electrode lead terminal comprises a second welding portion located in the welding area, wherein the first welding portion wraps at least a portion of the second welding portion; and / or the second welding portion wraps at least a portion of the first welding portion; the pole passes through the mounting hole, and the top cover sheet is located on one side of the electrode lead terminal along the direction from the second connection end to the first connection end;

[0041] The insulating sheet is clamped between the electrode lead terminal and the top cover sheet.

[0042] Beneficial effects of the embodiments of the present application:

[0043] In an embodiment of the present application, a welding area is formed at the connection between the electrode lead terminal of the pole structure and the second connection end of the pole, the pole includes a first welding portion located in the welding area, the electrode lead terminal includes a second welding portion located in the welding area, and the first welding portion wraps at least a portion of the second welding portion, or the second welding portion wraps at least a portion of the first welding portion. In this way, the bonding strength of the first welding portion and the second welding portion can be improved, thereby improving the connection strength between the electrode lead terminal and the second connection end of the pole, and improving the technical problem that the connection strength between the pole and the electrode lead terminal of the pole structure is insufficient, and the connection between the pole and the electrode lead terminal is prone to fracture. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 is a cross-sectional view of an embodiment of a top cover assembly provided by an embodiment of the present application, wherein the pole and the electrode lead terminal are in an unwelded state;

[0046] Figure 2 is a cross-sectional view of an embodiment of a top cover assembly provided by an embodiment of the present application, wherein the pole and the electrode lead terminal are in a welded state;

[0047] Figure 3 yes Figure 2 The enlarged view of point A in the middle;

[0048] Figure 4 yes Figure 3 The enlarged view of point B in the middle;

[0049] Figure 5 is a cross-sectional view of an embodiment of a battery provided in an embodiment of the present application;

[0050] Figure 6 It is an electronic image of a cross-sectional view of an embodiment of a welding area formed by welding and melting at a connection between an electrode lead terminal and a second connection end of an electrode column provided in an embodiment of the present application;

[0051] Figure 7 yes Figure 6 Total distribution map of each element in the welding area;

[0052] Figure 8 yes Figure 6 The element distribution diagram at each point on the line connecting point P and point Q;

[0053] Fig. 9 yes Figure 6 The overall distribution spectrum of elements at each point on the line connecting point P and point Q;

[0054] Fig.10 It is a flow chart of an embodiment of a method for preparing a pole structure provided in an embodiment of the present application;

[0055] Fig.11 It is a structural schematic diagram of an embodiment of the laser welding spot provided in the embodiment of the present application;

[0056] Fig.12 is a schematic structural diagram of an embodiment of a first spiral track and a second spiral track provided in an embodiment of the present application;

[0057] Fig.13 It is a structural schematic diagram of an embodiment of the present application in which the moving trajectory and the first annular trajectory are combined to form a first spiral trajectory;

[0058] Fig.14 It is a structural schematic diagram of an embodiment of the present application in which a moving trajectory and a second annular trajectory are combined to form a second spiral trajectory;

[0059] Fig.15 This is an example diagram of the welding area of ​​the pole structure provided in an embodiment of the present application.

[0060] Battery 1; top cover assembly 10; pole structure 11; pole 111; first connection end 1111; second connection end 1112; first welding portion 1113; first connection groove 1114; second fitting portion 1115; second fitting body 1116; second branch 1117; electrode lead terminal 112; second welding portion 1121; first fitting portion 1122; first fitting body 1123; first branch 1124; second connection groove 1125; welding area 113; top cover sheet 12; mounting hole 121; insulating sheet 13; battery cell 20; pole ear 21; laser welding spot 30; annular preheating spot 31; annular melting spot 32; first spiral trajectory 401; second spiral trajectory 402; moving trajectory 40; first annular trajectory 42; second annular trajectory 43. DETAILED DESCRIPTION

[0061] 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 those skilled in the art without creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the directional words such as "upper" and "lower" used generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0062] Embodiments of the present application provide a pole structure, a top cover assembly and a battery.

[0063] Figure 1 It is a cross-sectional view of an embodiment of a top cover assembly provided by an embodiment of the present application, wherein the pole and the electrode lead terminal are in an unwelded state. Figure 2 It is a cross-sectional view of an embodiment of a top cover assembly provided by an embodiment of the present application, wherein the pole and the electrode lead terminal are in a welded state. Figure 3 yes Figure 2 Enlarged view of point A in the middle. Figure 4 yes Figure 3 Enlarged view of point B in the middle. Figure 5 It is a cross-sectional view of an embodiment of a battery provided in an embodiment of the present application.

[0064] like Figure 1 , Figure 2 and Figure 5 As shown, the top cover assembly 10 includes a pole structure 11, which includes a pole 111 and an electrode lead terminal 112. The pole 111 includes a first connecting end 1111 and a second connecting end 1112 opposite to each other. The first connecting end 1111 of the pole 111 is used to connect with the pole ear 21 of the battery 1, and the electrode lead terminal 112 is connected to the second connecting end 1112 of the pole 111, so that the battery cell 20 of the battery 1 is electrically connected to the electrode lead terminal 112 through the pole ear 21 and the pole 111. When the electrode lead terminal 112 is connected to the bus bar, multiple batteries 1 can be connected in series or in parallel through the bus bar.

[0065] The electrode lead terminal 112 can be welded to the second connection end 1112 of the pole 111 to improve the connection strength between the electrode lead terminal 112 and the second connection end 1112 of the pole 111, thereby improving the working stability of the battery 1.

[0066] In order to further improve the connection strength between the second connection end 1112 of the pole 111 and the electrode lead terminal 112, in some embodiments, such as Figure 3 and Figure 4 As shown, a welding area 113 is formed at the connection between the electrode lead terminal 112 and the second connection end 1112 of the pole 111, the pole 111 includes a first welding portion 1113 located in the welding area 113, and the electrode lead terminal 112 includes a second welding portion 1121 located in the welding area 113, wherein the first welding portion 1113 wraps at least a portion of the second welding portion 1121. Thus, the bonding strength between the first welding portion 1113 and the second welding portion 1121 can be improved, thereby improving the connection strength between the electrode lead terminal 112 and the second connection end 1112 of the pole 111, and improving the technical problem that the connection strength between the pole 111 and the electrode lead terminal 112 of the pole structure 11 is insufficient, and the connection between the pole 111 and the electrode lead terminal 112 is prone to breakage.

[0067] Of course, the second welding portion 1121 can also wrap at least a portion of the first welding portion 1113, thereby improving the bonding strength between the first welding portion 1113 and the second welding portion 1121, and further improving the connection strength between the electrode lead terminal 112 and the second connecting end 1112 of the pole 111, thereby improving the technical problem that the connection strength between the pole 111 and the electrode lead terminal 112 of the pole structure 11 is insufficient, and the connection between the pole 111 and the electrode lead terminal 112 is prone to breakage.

[0068] It should be noted that in the embodiments of the present application, only the first welding portion 1113 can wrap at least a portion of the second welding portion 1121, or only the second welding portion 1121 can wrap at least a portion of the first welding portion 1113. It is also possible that the first welding portion 1113 wraps at least a portion of the second welding portion 1121 while the second welding portion 1121 wraps at least a portion of the first welding portion 1113. Of course, the latter can further improve the bonding strength between the first welding portion 1113 and the second welding portion 1121, so that the connection strength between the second connecting end 1112 of the pole 111 and the electrode lead terminal 112 is higher.

[0069] In addition, the welding area 113 is a region formed by heating and melting the connection between the electrode lead terminal 112 and the second connection end 1112 of the pole 111 through welding methods such as submerged arc welding and explosion welding, and then cooling and solidifying. In the process of forming the welding area 113 at the connection between the electrode lead terminal 112 and the second connection end 1112 of the pole 111, the first welding portion 1113 can be formed by at least a portion of the pole 111 located in the welding area 113 being melted, deformed and solidified; similarly, the second welding portion 1121 can be formed by at least a portion of the electrode lead terminal 112 located in the welding area 113 being melted, deformed and solidified.

[0070] In some embodiments, the first welding part 1113 and the second welding part 1121 can be embedded and diffused to make the first welding part 1113 wrap at least a part of the second welding part 1121; and / or, the second welding part 1121 wraps at least a part of the first welding part 1113, so that there is a stronger bonding strength between the first welding part 1113 and the second welding part 1121. The embedded diffusion composite means that part of the material of the first welding part 1113 is embedded in the second welding part 1121, and / or part of the material of the second welding part 1121 is embedded in the first welding part 1113. For example, the first welding part 1113 and the second welding part 1121 are two elements of different materials, part of the metal element of the first welding part 1113 is embedded in the second welding part 1121, and part of the metal element embedded in the second welding part 1121 is connected to the other part of the first welding part 1113, and part of the metal element of the second welding part 1121 is embedded in the first welding part 1113, and part of the metal element embedded in the first welding part 1113 is connected to the other part of the second welding part 1121. As a result, an irregular contact surface is formed at the junction of the first welding part 1113 and the second welding part 1121, and this irregular contact surface increases the interlocking strength of the first welding part 1113 and the second welding part 1121, making the connection between the first welding part 1113 and the second welding part 1121 more firmly. It is worth mentioning that the two materials of the first welding part 1113 and the second welding part 1121 are independent of each other, and do not form a metal bond or alloy, but the composite strength between the two is increased by the interlocking structure formed above.

[0071] In some embodiments, the welding area 113 can be solidified by heating the molten pool formed at the connection between the electrode lead terminal 112 and the pole 111, so that the first welding part 1113 and / or the second welding part 1121 melt and flow to form a structure in which the first welding part 1113 wraps at least a portion of the second welding part 1121, and / or a structure in which the second welding part 1121 wraps at least a portion of the first welding part 1113.

[0072] The first welding part 1113 and / or the second welding part 1121 may be heated or heated and pressurized at the same time, so that the first welding part 1113 and the second welding part 1121 can diffuse and recombine quickly. Specifically, the first welding part 1113 may be heated and melted, so that the high temperature of the first welding part 1113 melts at least a portion of the second welding part 1121, and the first welding part 1113 and the second welding part 1121 flow, so that the first welding part 1113 and the second welding part 1121 are interlocked and diffused, forming a welding area in which the first welding part 1113 wraps at least a portion of the second welding part 1121. Alternatively, the second welding part 1121 may be heated and melted, so that the high temperature of the second welding part 1121 melts at least a portion of the first welding part 1113, and the first welding part 1113 and the second welding part 1121 flow, so that the first welding part 1113 and the second welding part 1121 are interlocked and diffused, forming a welding area in which the second welding part 1121 wraps at least a portion of the first welding part 1113.

[0073] In some embodiments, Figure 1 As shown, the first welding part 1113 can be formed with a first connecting groove 1114, and the second welding part 1121 includes a first embedded part 1122, which is embedded in the first connecting groove 1114, so that the first welding part 1113 wraps the first embedded part 1122, that is, the first welding part 1113 wraps at least a portion of the second welding part 1121.

[0074] The first engaging portion 1122 of the second welding portion 1121 may include a first engaging body 1123 and a plurality of first branches 1124 protruding from the first engaging body 1123. Thus, when the first engaging portion 1122 of the second welding portion 1121 is engaged in the first connecting groove 1114 of the first welding portion 1113, the first engaging portion 1122 is less likely to be disengaged from the first connecting groove 1114, which is beneficial to improving the bonding strength between the first welding portion 1113 and the second welding portion 1121.

[0075] In some embodiments, the strength and / or hardness of the pole 111 can be made greater than the strength and / or hardness of the electrode lead terminal 112, so that during the welding connection between the second connection end 1112 of the pole 111 and the electrode lead terminal 112, it is easier to form a structure in which the first welding portion 1113 wraps at least a portion of the second welding portion 1121.

[0076] Specifically, the first connecting groove 1114 of the first welding part 1113 and the first interlocking part 1122 of the second welding part 1121 can be that during the process of the first welding part 1113 and the second welding part 1121 melting to form a molten pool, the molten first welding part 1113 and the second welding part 1121 flow to form the first connecting groove 1114 and the first interlocking part 1122 interlocked in the first connecting groove 1114.

[0077] It should be noted that only the strength of the pole 111 can be made greater than the strength of the electrode lead terminal 112, or only the hardness of the pole 111 can be made greater than the hardness of the electrode lead terminal 112. Alternatively, the strength and hardness of the pole 111 are both greater than the strength and hardness of the electrode lead terminal 112. Specifically, the pole 111 can be made of metal, which can include copper. Among them, the pole 111 can be an integrated structure to improve the strength and conductivity of the pole 111. The electrode lead terminal 112 is made of metal, which can include aluminum, so that the strength and hardness of the pole 111 are greater than the strength and hardness of the electrode lead terminal 112. Among them, the electrode lead terminal 112 can be an integrated structure to improve the strength and conductivity of the electrode lead terminal 112. Of course, the material of the pole 111 can also be aluminum or other metals, and the material of the electrode lead terminal 112 can also be copper or other metals.

[0078] Among them, the part of the second connection end 1112 of the pole 111 close to the electrode lead terminal 112 can be heated and melted by welding methods such as laser welding, submerged arc welding, and explosion welding to form a melting area. As the temperature of the melting area increases, the part of the electrode lead terminal 112 close to the melting area will also increase in temperature and melt to form a melting area. The melting area of ​​the pole 111 and the melting area of ​​the electrode lead terminal 112 together constitute a molten pool, and the part of the pole 111 located in the molten pool and the molten part of the electrode lead terminal 112 located in the molten pool will flow. After the parts of the pole 111 and the electrode lead terminal 112 in the molten pool are cooled and solidified, a first welding portion 1113 of the pole 111 and a second welding portion 1121 of the electrode lead terminal 112 will be formed. Among them, the first welding part 1113 that melts first is more likely to flow and wrap at least a portion of the molten second welding part 1121. Afterwards, when the first welding part 1113 and the second welding part 1121 are solidified, a structure in which the first welding part 1113 wraps at least a portion of the second welding part 1121 can be formed.

[0079] In other embodiments, the second welding portion 1121 can be formed with a second connecting groove 1125, and at least a portion of the first welding portion 1113 includes a second interlocking portion 1115, and the second interlocking portion 1115 is interlocked in the second connecting groove 1125, so that the second welding portion 1121 wraps at least a portion of the second interlocking portion 1115, that is, the second welding portion 1121 wraps at least a portion of the first welding portion 1113.

[0080] The second engaging portion 1115 of the first welding portion 1113 may include a second engaging body 1116 and a plurality of second branches 1117 protruding from the second engaging body 1116. Thus, when the second engaging portion 1115 of the first welding portion 1113 is engaged in the second connecting groove 1125 of the second welding portion 1121, the second engaging portion 1115 is less likely to be disengaged from the second connecting groove 1125, which is beneficial to improving the bonding strength between the first welding portion 1113 and the second welding portion 1121.

[0081] In some embodiments, the hardness and / or density of the pole 111 can be made smaller than the hardness and / or density of the lead terminal of the pole 111, so that during the welding connection between the second connection end 1112 of the pole 111 and the electrode lead terminal 112, it is easier to form a structure in which the second welding portion 1121 wraps at least part of the first welding portion 1113.

[0082] Specifically, the second connecting groove 1125 of the second welding part 1121 and the second interlocking part 1115 of the first welding part 1113 can be that during the process of the first welding part 1113 and the second welding part 1121 melting to form a molten pool, the molten first welding part 1113 and the second welding part 1121 flow to form the second connecting groove 1125 and the second interlocking part 1115 interlocked in the second connecting groove 1125.

[0083] It should be noted that only the strength of the pole 111 can be made smaller than the strength of the electrode lead terminal 112, or only the hardness of the pole 111 can be made smaller than the hardness of the electrode lead terminal 112. Alternatively, both the strength and hardness of the pole 111 can be made smaller than the strength and hardness of the electrode lead terminal 112. Specifically, the material of the pole 111 can include copper, and the material of the electrode lead terminal 112 can include aluminum, so that both the strength and hardness of the pole 111 are smaller than the strength and hardness of the electrode lead terminal 112.

[0084] Among them, the portion of the second connecting end 1112 of the electrode lead terminal 112 close to the pole 111 can be melted by welding methods such as laser welding, submerged arc welding, and explosion welding to form a melting area. As the temperature of the melting area increases, the portion of the second connecting end 1112 of the pole 111 close to the melting area will also increase in temperature and melt to form a melting area. The melting area of ​​the pole 111 and the melting area of ​​the electrode lead terminal 112 together constitute a molten pool, and the portion of the pole 111 located in the molten pool and the molten portion of the electrode lead terminal 112 located in the molten pool will flow. After the portions of the pole 111 and the electrode lead terminal 112 in the molten pool are cooled and solidified, a first welding portion 1113 of the pole 111 and a second welding portion 1121 of the electrode lead terminal 112 will be formed. Among them, the second welding part 1121 that melts first is more likely to flow and wrap at least part of the molten first welding part 1113. After that, when the first welding part 1113 and the second welding part 1121 are solidified, a structure in which the second welding part 1121 wraps at least part of the first welding part 1113 can be formed.

[0085] In some embodiments, the volume proportion of the first welding portion 1113 in the welding area 113 can be greater than or equal to 20%, and the volume proportion of the second welding portion 1121 in the welding area 113 can be greater than or equal to 30%, so that after the first welding portion 1113 wraps at least a portion of the second welding portion 1121, the bonding strength between the first welding portion 1113 and the second welding portion 1121 is higher.

[0086] Among them, the volume proportion of the first welding portion 1113 in the welding area 113 refers to the ratio of the volume of the first welding portion 1113 in the welding area 113 to the total volume of the welding area 113, and the first welding portion 1113 is non-uniformly distributed in the welding area 113. Similarly, the volume proportion of the second welding portion 1121 in the welding area 113 refers to the ratio of the volume of the second welding portion 1121 in the welding area 113 to the total volume of the welding area 113. The volume proportion of the first welding portion 1113 in the welding area 113 can be 25%, 35%, 40%, 45%, 50%, etc., and the volume proportion of the second welding portion 1121 in the welding area 113 can be 35%, 55%, 60%, 65%, 70%, etc., which can be determined according to the size of the welding area 113 and the materials of the pole 111 and the electrode lead terminal 112, and is not limited here.

[0087] Figure 6 It is an electronic image of a cross-sectional view of an embodiment of a welding area formed by welding and melting at the connection between the electrode lead terminal and the second connection end of the pole provided in an embodiment of the present application. Figure 7 for Figure 6 Distribution map of the total number of elements in the welding area. Figure 8 yes Figure 6 Distribution diagram of elements at each point on the line connecting point P and point Q. Fig. 9 yes Figure 6 The total distribution spectrum of elements at each point on the line connecting point P and point Q. Figures 6 to 9 As shown, the first welding part 1113 in the welding area 113 of the pole structure 11 in the embodiment of the present application wraps part of the second welding part 1121, and the first welding part 1113 and the second welding part 1121 have a high bonding strength. Among them, the material of the first welding part 1113 is copper (Cu), and the material of the second welding part 1121 is aluminum (Al). In the welding area 113, the volume of copper accounts for 50.62%, the volume of aluminum accounts for 40.97%, the volume of oxygen (O) accounts for 1.22%, and the volume of carbon (C) accounts for 7.19%. On the line connecting point P and point Q, the volume of copper accounts for 60.3%, the volume of aluminum accounts for 32.75%, the volume of oxygen (O) accounts for 0.75%, and the volume of carbon (C) accounts for 63.7%.

[0088] In some embodiments, the depth H of the welding area 113 can be greater than or equal to 0.5 mm. The width W of the welding area 113 can be greater than or equal to 1 mm. Thus, the first welding portion 1113 and the second welding portion 1121 have sufficient volume in the welding area 113 to ensure that the first welding portion 1113 and the second welding portion 1121 themselves have sufficient strength. When the first welding portion 1113 wraps at least a portion of the second welding portion 1121, or when the second welding portion 1121 wraps at least a portion of the first welding portion 1113, the bonding strength of the first welding portion 1113 and the second welding portion 1121 is higher.

[0089] Among them, the depth H of the welding area 113 can be 0.6mm, 0.7mm, 0.8mm, 1mm, etc., and the width W of the welding area 113 can be 1.1mm, 1.2mm, 1.3mm, 1.5mm, etc., which can be determined according to the size and material of the pole 111 and the electrode lead terminal 112, and is not limited here.

[0090] In some embodiments, the penetration depth of the first weld 1113 can be made smaller than the penetration depth of the second weld 1121, so that during the formation of the first weld 1113 and the second weld 1121, a structure is formed in which the first weld 1113 wraps around at least a portion of the second weld 1121 and / or the second weld 1121 wraps around at least a portion of the first weld 1113.

[0091] The penetration depth of the first welding part 1113 can be greater than or equal to 0.3 mm, and the penetration depth of the second welding part 1121 can be greater than or equal to 0.5 mm, so that after the molten pool solidifies, the first welding part 1113 can wrap at least a portion of the second welding part 1121, or the second welding part 1121 can wrap at least a portion of the first welding part 1113. The penetration depth of the first welding part 1113 can be 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, etc., and the penetration depth of the second welding part 1121 can be 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, etc., which can be determined according to the structure of the pole junction 111 and the electrode lead terminal 112.

[0092] In some embodiments, the welding area 113 can be extended along the circumference of the pole 111 to extend the length of the welding area 113, thereby increasing the connection length between the pole 111 and the electrode lead terminal 112. Specifically, the welding area 113 can be extended along the circumference of the second connection end 1112 of the pole 111 to form an annular structure.

[0093] In order to better prepare the pole structure provided in the embodiment of the present application, the embodiment of the present application also provides a method for preparing the pole structure. Fig.10 As shown, the pole structure preparation method includes steps S210 to S230, which are described in detail as follows:

[0094] S210, providing a pole 111, the pole 111 including a first connecting end 1111 and a second connecting end 1111 opposite to each other

[0095] 1112 , the first connection end 1111 is used to connect to the tab 21 of the battery 1 .

[0096] The structure and material of the pole 111 may refer to the above embodiments.

[0097] S220 , providing electrode lead terminals 112 .

[0098] The structure and material of the electrode lead terminal 112 may refer to the above-mentioned embodiments.

[0099] S230, welding the electrode lead terminal 112 to the second connection end 1112 of the pole 111 to form a welding area 113 at the connection between the electrode lead terminal 112 and the pole 111, so that the first welding portion 1113 of the pole 111 located in the welding area wraps at least a portion of the second welding portion 1121 of the electrode lead terminal 112 located in the welding area, and / or, the second welding portion 1121 of the electrode lead terminal 112 located in the welding area 113 wraps at least a portion of the first welding portion 1113 of the pole 111 located in the welding area 113.

[0100] The pole structure preparation method provided in the embodiment of the present application welds the electrode lead terminal 112 to the second connection end 1112 of the pole 111 to form a welding area 113 at the connection between the electrode lead terminal 112 and the pole 111, so that the first welding portion 1113 of the pole 111 located in the welding area 113 wraps at least a portion of the second welding portion 1121 of the electrode lead terminal 112 located in the welding area 113, and / or, the second welding portion 1121 of the electrode lead terminal 112 located in the welding area 113 wraps at least a portion of the first welding portion 1113 of the pole located in the welding area 113, which can improve the bonding strength between the first welding portion 1113 and the second welding portion 1121, thereby improving the connection strength between the electrode lead terminal 112 and the second connection end 1112 of the pole 111, and improving the technical problem that the connection strength between the pole 111 and the electrode lead terminal 112 of the pole structure 11 is insufficient, and the connection between the pole 111 and the electrode lead terminal 112 is prone to breakage.

[0101] Among them, the welding area 113 can be solidified by the molten pool formed by heating the connection between the electrode lead terminal 112 and the pole 111, so that the first welding part 1113 and / or the second welding part 1121 melt and flow to form a structure in which the first welding part 1113 wraps at least part of the second welding part 1121.

[0102] Specifically, the first welding part 1113 may be heated or heated and pressurized at the same time, so that the first welding part 1113 and the second welding part 1121 can be quickly embedded and diffused and composited. After the first welding part 1113 is heated and melted, the high temperature of the first welding part 1113 melts at least a portion of the second welding part 1121, and the first welding part 1113 and the second welding part 1121 flow, so that the first welding part 1113 and the second welding part 1121 are embedded and diffused and composited, forming a welding area 113 in which the first welding part 1113 wraps at least a portion of the second welding part 1121.

[0103] Alternatively, the second welding part 1121 may be heated and melted so that the high temperature of the second welding part 1121 melts at least a portion of the first welding part 1113, and the first welding part 1113 and the second welding part 1121 flow so that the first welding part 1113 and the second welding part 1121 are interlocked and diffused to form a welding area 113 in which the second welding part 1121 wraps at least a portion of the first welding part 1113.

[0104] The electrode lead terminal 112 can be welded to the second connection end 1112 of the pole 111 by laser, which can make the heating of the electrode lead terminal 112 and the second connection end 1112 of the pole 111 more accurate and rapid, which is conducive to improving welding efficiency. Of course, the electrode lead terminal 112 can also be welded to the second connection end 1112 of the pole 111 by welding methods such as submerged arc welding and explosion welding to form a welding area 113.

[0105] In some embodiments, the step of welding the electrode lead terminal 112 to the second connection end 1112 of the electrode column 111 to form the welding area 113 may include step S231 and step S232, which are described in detail as follows:

[0106] S231 , forming a laser welding spot 30 at the connection between the second connection end 1112 and the electrode lead terminal 112 .

[0108] Among them, Fig.11 As shown, a laser can be emitted to the connection between the second connection end 1112 of the pole 111 and the electrode lead terminal 112 by a laser to form a laser welding spot 30 at the connection between the second connection end 1112 and the electrode lead terminal 112. When the laser welding spot 30 can heat the connection between the second connection end 1112 and the electrode lead terminal 112, the connection between the second connection end 1112 and the electrode lead terminal 112 is heated and melted to form a molten pool.

[0109] In some embodiments, the laser welding spot 30 may include an annular melting spot 32 and an annular preheating spot 31, the power of the annular melting spot 32 is greater than the power of the annular preheating spot 31, and the annular preheating spot 31 and the annular melting spot 32 are sequentially distributed along the moving direction of the laser welding spot 30. Thus, the annular preheating spot 31 can preheat the area to be welded at the connection between the second connection end 1112 and the electrode lead terminal 112, so as to improve the efficiency of the annular melting spot 32 in melting the connection between the second connection end 1112 and the electrode lead terminal 112.

[0110] S232. Control the laser welding spot 30 to move along the moving trajectory 40 while swinging along the swinging trajectory in a direction intersecting the moving trajectory 40 to weld the electrode lead terminal 112 to the second connection end 1112 of the pole 111 to form a welding area 113; wherein the moving trajectory 40 extends along the circumference of the pole 111 and is located on the surface of the electrode lead terminal 112 or the surface of the second connection end 1112; the swinging trajectory intersects with the connection between the second connection end 1112 and the electrode lead terminal 112.

[0111] By controlling the laser welding spot 30 to move along a moving trajectory 40 located on the surface of the electrode lead terminal 112 or the surface of the second connection end 1112, and making the laser welding spot 30 swing along a swinging trajectory that intersects the connection between the second connection end 1112 and the electrode lead terminal 112 in a direction intersecting the moving trajectory 40, the second connection end 1112 of the pole 111 and the electrode lead terminal 112 can be quickly melted in the area irradiated by the welding spot to form a structure in which the first welding portion 1113 wraps part of the second welding portion 1121, and / or the second welding portion 1121 wraps part of the first welding portion 1113, which is beneficial to improving welding efficiency.

[0112] At the same time, if Fig.15 As shown, the welding effect of the second connection end 1112 of the pole 111 and the electrode lead terminal 112 can be significantly improved, so that a fish-scale weld with high welding quality is formed at the connection between the second connection end 1112 and the electrode lead terminal 112, and the molten pool is not prone to cracking. It also avoids the problem of excessive power of the laser welding spot 30 causing the pole 111 structure to melt the sealant, and can also avoid the problem of insufficient power of the laser welding spot 30 causing the first welding part 1113 and the second welding part 1121 to melt insufficiently, and unable to form a structure in which one wraps the other.

[0113] It should be noted that the actual trajectory of the laser welding spot 30 is a composite trajectory along the moving trajectory 40 and the swinging trajectory, that is, the laser welding spot 30 moves along the moving trajectory 40 as a whole and swings back and forth along the swinging trajectory.

[0114] Among them, Figure 12 to Figure 14 As shown, the swing trajectory can include a first annular trajectory 42 and a second annular trajectory 43 that respectively intersect the connection between the second connection end 1112 and the electrode lead terminal 112, the annular preheating spot 31 swings along the first annular trajectory 42, and the annular melting spot 32 swings along the second annular trajectory 43, so that the annular preheating spot 31 can effectively preheat the area to be melted at the connection between the second connection end 1112 and the electrode lead terminal 112.

[0115] That is, the real trajectory of the annular preheating light spot 31 is a first spiral trajectory 401 formed by the moving trajectory 40 and the first annular trajectory 42, that is, the annular preheating light spot 31 moves along the moving trajectory 40 as a whole and swings back and forth along the first annular trajectory 42. The real trajectory of the annular melting light spot 32 is a second spiral trajectory 402 formed by the moving trajectory 40 and the second annular trajectory 43, that is, the annular melting light spot 32 moves along the moving trajectory 40 as a whole and swings back and forth along the second annular trajectory 43.

[0116] It should be noted that the center point of the annular preheating spot 31 can be located on the moving trajectory 40 and the first swinging trajectory, and the center point of the annular melting spot 32 can be located on the moving trajectory 40 and the second swinging trajectory, so that the relative positions of the annular preheating spot 31 and the annular melting spot 32 remain stable, and thus the preheating effect of the annular preheating spot 31 remains stable.

[0117] The shapes of the first annular track 42 and the second annular track 43 can be circular, elliptical, etc. When the shapes of the first annular track 42 and the second annular track 43 are circular, the radius of the first annular track 42 and the second annular track 43 can be 0.5 mm, 0.6 mm, 0.7 mm, etc., which can be determined according to the size, power and other parameters of the annular preheating spot 31 and the annular melting spot 32.

[0118] The pitch of the first spiral track 401 and / or the pitch of the second spiral track 402 may be greater than or equal to 0.3 mm and less than or equal to 0.6 mm. Specifically, the pitch of the first spiral track 401 and / or the pitch of the second spiral track 402 may be 0.4 mm, 0.5 mm, etc., which may be determined according to the size, power and other parameters of the annular preheating spot 31 and the annular melting spot 32.

[0119] In some embodiments, the ratio of the power of the annular melting spot 32 to the power of the annular preheating spot 31 can be greater than or equal to 110% and less than or equal to 130%, so that the annular preheating spot 31 has a better preheating effect on the area to be melted, and the annular melting spot 32 can quickly melt the area to be melted while reducing the waste of power of the annular preheating spot 31 or the annular melting spot 32.

[0120] In some embodiments, the speed at which the laser welding spot 30 moves along the moving track 40 can be greater than or equal to 480 mm / s and less than or equal to 520 mm / s, thereby improving the welding effect of the laser welding spot 30. The speed at which the laser welding spot 30 moves along the moving track 40 can be 490 mm / s, 500 mm / s, 510 mm / s, etc., which can be determined according to parameters such as the power of the laser welding spot 30 and the size of the pole 111 structure.

[0121] An embodiment of the present application also provides a top cover assembly, which includes a pole structure. The pole structure refers to the above-mentioned embodiment. Since the top cover assembly adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0122] like Figure 2As shown, the top cover assembly 10 may include a top cover sheet 12, a pole structure 11 and an insulating sheet 13, the top cover sheet 12 having a through mounting hole 121; the pole structure 11 may refer to the above embodiments, which will not be described here. The pole 111 of the pole structure 11 passes through the mounting hole 121, and the top cover sheet 12 is located on one side of the electrode lead terminal 112 of the pole structure 11 along the direction from the second connection end 1112 to the first connection end 1111 of the pole 111. The insulating sheet 13 is clamped between the electrode lead terminal 112 and the top cover sheet 12.

[0123] The top cover assembly 10 provided in the embodiment of the present application is such that the first welding portion 1113 of the pole structure 11 wraps at least a portion of the second welding portion 1121, or the second welding portion 1121 wraps at least a portion of the first welding portion 1113. In this way, the bonding strength between the first welding portion 1113 and the second welding portion 1121 can be improved, thereby improving the connection strength between the electrode lead terminal 112 and the second connection end 1112 of the pole 111, improving the technical problem that the connection strength between the pole 111 and the electrode lead terminal 112 of the pole structure 11 is insufficient, and the connection between the pole 111 and the electrode lead terminal 112 is prone to fracture, thereby improving the connection stability between the battery 1 tab 21 and the electrode lead terminal 112, and making the battery 1 more stable.

[0124] An embodiment of the present application also provides a battery, which includes a top cover assembly. The specific structure of the top cover assembly refers to the above embodiment. Since the battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0125] Among them, Figure 5 As shown, the battery 1 may include a battery cell 20 , wherein the battery cell 20 has a pole tab 21 , and the pole tab is electrically connected to a first connection end 1111 of a pole post 111 of a pole post structure 11 .

[0126] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A pole structure, characterized in that: The pole structure comprises: A pole, comprising a first connecting end and a second connecting end opposite to each other, wherein the first connecting end is used to be connected to a pole lug of a battery; An electrode lead terminal is welded to the second connection end of the pole, and a welding area is formed at the connection between the electrode lead terminal and the pole; The pole includes a first welding portion located in the welding area, the electrode lead terminal includes a second welding portion located in the welding area, the first welding portion wraps at least a portion of the second welding portion; and / or the second welding portion wraps at least a portion of the first welding portion.

2. The pole structure according to claim 1, characterized in that: The first welding part and the second welding part are interlocked and diffusely composited, so that the first welding part wraps at least a portion of the second welding part; and / or the second welding part wraps at least a portion of the first welding part.

3. The pole structure according to claim 1, characterized in that: The welding area is formed by solidifying a molten pool formed by heating the connection between the electrode lead terminal and the pole.

4. The pole structure according to claim 1, characterized in that: The first welding portion is formed with a first connecting groove, the second welding portion includes a first embedding portion, and the first embedding portion is embedded in the first connecting groove; and / or, The second welding portion is formed with a second connecting groove, and the first welding portion includes a second embedding portion, and the second embedding portion is embedded in the second connecting groove.

5. The pole structure according to claim 4, characterized in that: The first engaging portion includes a first engaging body and a plurality of first branches protruding from the first engaging body; and / or, The second engaging portion includes a second engaging body and a plurality of second branches protruding from the second engaging body.

6. The pole structure according to claim 1, characterized in that: The hardness and / or density of the pole is greater than the hardness and / or density of the electrode lead terminal; or, The hardness and / or density of the pole is smaller than the hardness and / or density of the electrode lead terminal.

7. The pole structure according to claim 1, characterized in that: The first welding portion accounts for greater than or equal to 20% of the volume of the welding area, and the second welding portion accounts for greater than or equal to 30% of the volume of the welding area.

8. The pole structure according to any one of claims 1 to 7, characterized in that: The welding area extends along the circumference of the pole.

9. The pole structure according to any one of claims 1 to 7, characterized in that: The material of the pole includes copper, and the material of the electrode lead terminal includes aluminum.

10. The pole structure according to any one of claims 1 to 7, characterized in that: The pole is an integrated structure, and the pole is made of metal; and / or, The electrode lead terminal is an integrated structure, and the material of the electrode lead terminal is metal.

11. The pole structure according to any one of claims 1 to 7, characterized in that: The depth of the welding area is greater than or equal to 0.5 mm; the width of the welding area is greater than or equal to 1 mm.

12. The pole structure according to any one of claims 1 to 7, characterized in that: The penetration depth of the first weld portion is smaller than the penetration depth of the second weld portion.

13. The pole structure according to claim 12, characterized in that: The penetration depth of the first weld portion is greater than or equal to 0.3 mm; the penetration depth of the second weld portion is greater than or equal to 0.5 mm.

14. A method for preparing a pole structure, characterized in that: The method comprises: Providing a pole, the pole comprising a first connecting end and a second connecting end opposite to each other, the first connecting end being used for connecting to a pole lug of a battery; Providing electrode lead terminals; The electrode lead terminal is welded to the second connection end of the pole to form a welding area at the connection between the electrode lead terminal and the pole, so that the first welding portion of the pole located in the welding area wraps at least a portion of the second welding portion of the electrode lead terminal located in the welding area, and / or the second welding portion of the electrode lead terminal located in the welding area wraps at least a portion of the first welding portion of the pole located in the welding area.

15. The method for preparing a pole structure according to claim 14, characterized in that: The step of welding the electrode lead terminal to the second connection end of the pole to form a welding area includes: forming a laser welding spot at a connection between the second connection end and the electrode lead terminal; The laser welding spot is controlled to move along a moving trajectory while swinging along a swinging trajectory in a direction intersecting the moving trajectory to weld the electrode lead terminal to the second connecting end of the pole to form a welding area; wherein the moving trajectory extends along the circumference of the pole and is located on the surface of the electrode lead terminal or the surface of the second connecting end; and the swinging trajectory intersects the connection between the second connecting end and the electrode lead terminal.

16. The method for preparing a pole structure according to claim 15, characterized in that: The laser welding spot includes an annular melting spot and an annular preheating spot, the power of the annular melting spot is greater than the power of the annular preheating spot, and the annular preheating spot and the annular melting spot are distributed in sequence along the moving direction of the laser welding spot; The swing track includes a first annular track and a second annular track respectively intersecting with the connection between the second connection end and the electrode lead terminal, the annular preheating spot swings along the first annular track, and the annular melting spot swings along the second annular track.

17. The method for preparing a pole structure according to claim 16, characterized in that: The ratio of the power of the annular melting light spot to the power of the annular preheating light spot is greater than or equal to 110% and less than or equal to 130%.

18. A top cover assembly, characterized in that: include: A top cover sheet having a penetrating mounting hole; A pole structure, wherein the pole structure is the pole structure according to any one of claims 1 to 13, or the pole structure is the pole structure prepared by the pole structure preparation method according to any one of claims 14 to 17, wherein the pole of the pole structure passes through the mounting hole, and the top cover sheet is located on one side of the electrode lead terminal of the pole structure along the direction from the second connection end to the first connection end of the pole; The insulating sheet is clamped between the electrode lead terminal and the top cover sheet.

19. A battery, characterized in that: Includes the top cover assembly of claim 18.

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