Battery and electric equipment

Abstract

The utility model provides a battery and electric equipment. The battery comprises a shell, an end cover and a confluence plate, the confluence disc comprises a disc body and a lap joint part, and the lap joint part is annularly arranged on the outer side of the disc body in the circumferential direction of the disc body. An opening is formed in one end, in the first direction, of the shell, at least part of the lap joint part is in lap joint with the opening end face of the shell, the end cover is arranged on the side, away from the shell, of the convergence disc, and the lap joint part and the shell as well as the lap joint part and the end cover are in welded connection; the outer diameter R1 of the lap joint part, the inner diameter R2 of the opening end face and the outer diameter R3 of the opening end face meet the condition that R1 is larger than R2 and smaller than R3, and therefore the welding efficiency and the welding reliability are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, concretely relates to a battery and electric equipment. BACKGROUND

[0002] Lithium ion batteries, such as cylindrical lithium ion batteries, have been gradually widely applied to electric vehicles, electric bicycles and other products due to the advantages of high energy density, high efficiency and the like.

[0003] The cylindrical lithium ion battery usually includes a shell, an electric core, a busbar and an end cover located at the end of the shell, the electric core and the busbar are arranged in the shell, and the electric core is connected with the end cover through the busbar to connect the power supply. However, the welding reliability and welding efficiency of the cylindrical battery in the related art are low during the assembling process. SUMMARY

[0004] Therefore, the utility model embodiment is dedicated to providing a battery and electric equipment to improve the welding reliability and welding efficiency of the battery to a certain extent.

[0005] In a first aspect, the utility model provides a kind of batteries, including shell, end cover and busbar;

[0006] The busbar includes disc body and lap joint portion, and the lap joint portion is circumferentially arranged on the outer side of the disc body;

[0007] The shell has an opening at one end in the first direction, at least part of the lap joint portion is lapped on the opening end surface of the shell, the end cover is arranged on the side of the busbar away from the shell, and the lap joint portion and the shell are welded and connected between the lap joint portion and the end cover.

[0008] Wherein, the outer diameter R1 of the lap joint portion, the inner diameter R2 of the opening end surface and the outer diameter R3 of the opening end surface satisfy: R2

[0009] Optionally, the thickness h1 of the lap joint portion in the first direction satisfies: 0.1mm≤h1≤0.5mm.

[0010] Optionally, the outer edge of the projection of the lap joint portion on the opening end surface is located on the inner side of the outer edge of the opening end surface.

[0011] And / or, the projection length b of the end cover on the opening end surface and the projection length a of the lap joint portion on the opening end surface satisfy: b-a>0.1mm.

[0012] And / or, in the first direction, the thickness h1 of the lap joint portion and the thickness h2 of the end cover at the corresponding position of the opening end surface satisfy: h1 / h2≤2 / 3.

[0013] Optionally, the outer edge of the projection of the lap joint on the opening end surface is located inside the outer edge of the opening end surface.

[0014] The end cover has a bending portion extending towards the housing, and the bending portion surrounds the outside of the lap joint.

[0015] Optionally, a groove is formed at the joint of the lap joint and the disc.

[0016] Optionally, in the first direction, the groove depth h3 satisfies h3≥0.1mm.

[0017] Optionally, in the first direction, the disc protrudes towards the inner cavity of the housing relative to the lap joint, and the outer wall surface of the disc and the lap joint jointly form a first positioning portion cooperating with the housing.

[0018] Optionally, the inner diameter R4 of the lap joint and the inner diameter R2 of the opening end surface satisfy R2-0.1mm≤R4≤R2+0.1mm.

[0019] And / or, the included angle r between the outer wall surface of the disc and the horizontal plane satisfies 80°<r<95°.

[0020] And / or, the end cover has a second positioning portion cooperating with the disc.

[0021] Optionally, the disc includes a connecting region and a stretching region, the stretching region is arranged outside the connecting region along the circumferential direction of the connecting region, and the lap joint is arranged outside the stretching region along the circumferential direction of the stretching region.

[0022] The stretching region protrudes towards the inner cavity of the housing, and the outer wall surface of the stretching region and the lap joint jointly form the first positioning portion.

[0023] In the first direction, the projection length h4 of the stretching region on the housing satisfies h4≥0.2mm.

[0024] Optionally, the inner diameter R2 of the opening end surface and the outer diameter R3 of the opening end surface satisfy 0.2mm≤R3-R2≤0.8mm.

[0025] And / or, in the first direction, the total thickness h of the busbar satisfies:

[0026] 0.5mm<h<2mm.

[0027] And / or, the disk body includes a connection area, an elastic connection part and a stretching area; the stretching area is arranged on the outside of the connection area along the circumference of the connection area, the overlapping part is arranged on the outside of the stretching area along the circumference of the stretching area, and along the first direction, there is a distance between the connection area and the stretching area, and the connection area is connected to the stretching area through the elastic connection part.

[0028] Optionally, the material of the end cover is the same as that of the shell, and different from that of the busbar.

[0029] Optionally, the end cover is a steel end cover, the shell is a steel shell, and the busbar is a copper busbar.

[0030] Optionally, the effective penetration depth of the metallographic structure formed at the welding point of the end cover, the overlapping portion and the shell satisfies: effective penetration depth>0.15mm;

[0031] And / or, an effective weld width of a metallographic structure formed at a welding point between the end cover, the overlapping portion, and the shell satisfies: effective weld width > 0.8 mm.

[0032] In a second aspect, the present invention provides an electrical device comprising the battery as described above.

[0033] The battery and electrical equipment provided by the utility model are such that the busbar includes a busbar body and an overlapping portion arranged on the circumferential outside of the busbar body, so that at least part of the overlapping portion is overlapped on the open end face of the shell, and the end cover is located on the side of the busbar facing away from the shell, and the overlapping portion and the shell, as well as the overlapping portion and the end cover are welded together. In this way, during assembly, the overlapping portion is overlapped on the open end face of the shell, and the end cover is overlapped on the side of the busbar facing away from the shell, so that the one-time welding of the three structural components of the shell, the busbar and the end cover can be completed through a one-time welding process. Compared with the solution of first welding the busbar to the shell and then welding the shell to the end cover, the above arrangement of the utility model saves the welding process and improves the welding efficiency. At the same time, by ensuring that the outer diameter R1 of the overlapped portion, the inner diameter R2 of the open end face, and the outer diameter R3 of the open end face satisfy the following relationship: R2 < R1 < R3, the overlapped portion is reliably overlapped on the shell, thereby improving the convenience and stability of the welding operation, and further improving the reliability and yield of the welding. Moreover, this arrangement can, to a certain extent, avoid the situation where the proportion of the busbar material components is too high during welding melting, which leads to an increase in the proportion of weld pores and cracks, resulting in welding defects, thus further improving the reliability and yield of the welding. In addition, this arrangement can also achieve a certain degree of covering of the busbar by the shell and end cover during welding melting, thereby improving the strength and stability of the overall structure formed after welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A structure schematic view of the battery according to an embodiment of the present application;

[0035] Figure 2 A structure schematic view of the battery according to an embodiment of the present application; Figure 1 A corresponding side structure schematic view;

[0036] Figure 3 A structure schematic view of the battery according to an embodiment of the present application; Figure 2 A sectional view of A-A direction in the structure schematic view of the battery according to an embodiment of the present application;

[0037] Figure 4 A structure enlarged view of I in the structure schematic view of the battery according to an embodiment of the present application; Figure 3 A structure enlarged view of I in the structure schematic view of the battery according to an embodiment of the present application;

[0038] Figure 5 A structure enlarged view of I in the structure schematic view of the battery according to an embodiment of the present application; Figure 4 A structure enlarged view of I in the structure schematic view of the battery according to an embodiment of the present application;

[0039] Figure 6 A structure schematic view of the battery according to an embodiment of the present application; Figure 5 A structure schematic view of the battery according to an embodiment of the present application;

[0040] Figure 7 A structure schematic view of the busbar according to an embodiment of the present application;

[0041] Figure 8 A top structure schematic view of the busbar according to an embodiment of the present application;

[0042] Figure 9 A structure schematic view of the busbar according to an embodiment of the present application; Figure 8 A sectional view of A-A direction in the structure schematic view of the busbar according to an embodiment of the present application;

[0043] Figure 10 A structure enlarged view of I in the structure schematic view of the busbar according to an embodiment of the present application; Figure 9 A structure enlarged view of I in the structure schematic view of the busbar according to an embodiment of the present application;

[0044] 1, shell; 10, gap; 11, open end face; 2, end cover; 21, second positioning part; 22, bending part; 3, busbar; 31, disc body; 310, outer wall face; 311, connecting area; 312, stretching area; 313, elastic connecting part; 32, lapping part; 321, groove; 301, liquid injection hole; 302, liquid permeation channel; 303, first positioning part; 4, battery cell; 5, pole; 6, sealing element. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application belong to the scope of protection of the present application.

[0046] The cylindrical lithium ion battery usually comprises a shell, an electrode core, a busbar and an end cover, the electrode core and the busbar are arranged in the shell, and the electrode core is connected with the end cover through the busbar to connect the power supply. During specific assembly, the busbar is welded with the shell first, and then the shell is welded with the end cover, which results in low welding efficiency and reliability of the cylindrical battery during the assembly process.

[0047] Therefore, the utility model discloses a battery and electric equipment, through the lap joint of the busbar lap joint on the open end surface of the shell, the end cover is located on the side of the busbar away from the shell, make the lap joint between the shell and the end cover, and the lap joint between the end cover and the shell is welded, and the outer diameter of the lap joint of the busbar is between the inner diameter of the open end surface of the shell and the outer diameter of the open end surface, so that the busbar, the shell and the end cover are lap jointed together through the lap joint mode, and one-time welding of the three can be realized through one-time welding process, thereby saving the welding process, and improving the welding efficiency and reliability.

[0048] The battery and electric equipment provided by the utility model will be described in detail below with specific embodiments in combination with the drawings:

[0049] Referring to Figures 1 to 10 The battery provided by the embodiment can be a cylindrical battery, and specifically can be a cylindrical lithium ion battery. The battery can be used as a power supply or an energy storage unit of an electronic device, and the electronic device can include but is not limited to an electric vehicle (for example, a pure electric vehicle, a hybrid electric vehicle, an electric bicycle, etc.).

[0050] The battery specifically comprises a shell 1, an electrode core 4, an end cover 2 and a busbar 3. The electrode core 4 is located in the shell 1.

[0051] Referring to Figures 1 to 3 The shell 1 can be a hollow cylindrical shell, and the shell 1 has an opening at one end in a first direction. The first direction can be the up-down direction as shown in the middle, and specifically can be the axial direction of the battery. The one end of the shell 1 in the first direction can be the bottom end of the shell 1. Figure 3

[0052] Specifically, the battery comprises a positive busbar, a negative busbar, a positive end cover and a negative end cover. Referring to Figures 1 to 3 For example, the positive busbar and the positive end cover are located at the top of the shell 1, the positive end cover has a pole 5, and the positive busbar is connected with the positive lug of the electrode core and the pole 5. The negative busbar and the negative end cover are located at the bottom of the shell 1.

[0053] The busbar 3 described in the embodiment can be a busbar at the bottom of the shell 1, for example, a negative busbar, and correspondingly, the end cover 2 described in the embodiment can be an end cover at the bottom of the shell 1. ​

[0054] The busbar 3 specifically includes a body 31 and an overlap portion 32, wherein the overlap portion 32 is provided on the outside of the body 31 along the circumference of the body 31. For example, the busbar 3 can be an integral stamped structure having an annular overlap portion 32 manufactured by mechanical stamping.

[0055] At least part of the overlap portion 32 overlaps the open end surface 11 of the shell 1 , and the end cover 2 is arranged on the side of the busbar 3 away from the shell 1 . The overlap portion 32 and the shell 1 and the overlap portion 32 and the end cover 2 are welded.

[0056] That is to say, during the specific assembly, the overlapping portion 32 of the busbar 3 is overlapped on the open end face 11 of the shell 1, and the end cover 2 is overlapped on the side of the busbar 3 facing away from the shell 1, that is, the end of the end cover 2 is overlapped on the overlapping portion 32, and then the three structural components of the shell 1, the busbar 3, and the end cover 2 can be welded into one through a one-time welding process, thereby realizing welding and sealing between the shell 1, the busbar 3 and the end cover 2, and improving welding efficiency.

[0057] In a specific implementation, for example, the body 31 of the busbar 3 can be first welded to the negative terminal tab of the battery cell 4. The overlapping portion 32 of the busbar 3, the housing 1, and the end cap 2 can then be overlapped together, performing a one-time welding of the overlapping portion 32 of the busbar 3, the housing 1, and the end cap 2. The body 31 has an injection hole 301 in the middle, and a liquid seepage channel 302 connected to the injection hole 301. Electrolyte is injected through the injection hole 301. The liquid seepage channel 302 can evenly disperse the electrolyte injected from the injection hole 301 into the battery cell 4, which not only facilitates electrolyte infiltration but also shortens the injection and immersion time. After formation is completed, the battery is sealed by welding the seal 6.

[0058] In order to ensure the reliability of the overlap and thus improve the welding efficiency, welding yield and welding reliability, the outer diameter R1 of the overlap portion 32, the inner diameter R2 of the opening end surface 11 and the outer diameter R3 of the opening end surface 11 can satisfy the following relationship:

[0059] R2<R1<R3.

[0060] Reference Figure 3 and Figure 4 As shown, the inner diameter R2 of the opening end face 11, that is, the inner ring of the opening end face 11, is along the Figure 3 The diameter dimension in the left and right directions is the outer diameter R3 of the opening end face 11, that is, the outer ring of the opening end face 11 is along the Figure 3 Diameter dimension in left and right direction. Figure 9 As shown, the outer diameter R1 of the overlap portion 32, i.e., the outer ring of the overlap portion 32, is Figure 9 Diameter dimension in the left-right direction.

[0061] The arrangement ensures reliable lapping of the lapping portion 32 on the shell 1, thereby improving welding efficiency, welding yield and welding reliability. Moreover, the arrangement can to some extent avoid the situation that the proportion of the material components of the busbar 3 is too high during welding melting, which leads to an increase in the proportion of welding pores and cracks, causing welding defects, i.e., further improving the welding yield, welding reliability and structural strength. In addition, the arrangement can also achieve the coverage of the shell 1 and the end cover 2 on the busbar 3 to some extent during welding melting, thereby improving the strength and stability of the overall structure formed after welding.

[0062] For example, a ring-shaped light spot laser can be used to weld the busbar 3, the shell 1 and the end cover 2 at one time.

[0063] The battery provided by the embodiment includes the busbar 3, the shell 1 and the end cover 2. The busbar 3 includes a disc body 31 and a lapping portion 32 arranged on the outer circumferential side of the disc body 31. At least part of the lapping portion 32 is lapped on the open end surface 11 of the shell 1. The end cover 2 is arranged on the side of the busbar 3 away from the shell 1. The lapping portion 32 is welded and connected with the shell 1 and the end cover 2. In the assembly, the lapping portion 32 is lapped on the open end surface 11 of the shell 1, and the end cover 2 is lapped on the side of the busbar 3 away from the shell 1. Thus, the welding of the shell 1, the busbar 3 and the end cover 2 can be completed at one time by one welding process. Compared with the scheme of welding the busbar 3 on the shell 1 first and then welding the shell 1 and the end cover 2, the embodiment saves the welding process, thereby improving the welding efficiency. At the same time, the outer diameter R1 of the lapping portion 32, the inner diameter R2 of the open end surface 11 and the outer diameter R3 of the open end surface 11 satisfy R2 < R1 < R3, which ensures reliable lapping of the lapping portion 32 on the shell 1, thereby improving the convenience and stability during welding operation, and further improving the welding reliability and welding yield. Moreover, the arrangement can to some extent avoid the situation that the proportion of the material components of the busbar 3 is too high during welding melting, which leads to an increase in the proportion of welding pores and cracks, causing welding defects, i.e., further improving the welding reliability and welding yield. In addition, the arrangement can also achieve the coverage of the shell 1 and the end cover 2 on the busbar 3 to some extent during welding melting, thereby improving the strength and stability of the overall structure formed after welding.

[0064] In some embodiments, the material of the end cover 2 is the same as that of the shell 1, and different from that of the busbar 3. Since the material of the end cover 2 is the same as that of the shell 1, the end cover 2 and the shell 1 can be better combined together during welding melting, thereby making the end cover 2 and the shell 1 have a better coverage effect on the lapping portion 32, and further improving the welding yield, welding reliability and structural strength after welding.

[0065] Specifically, the end cover 2 can be a steel end cover, the shell 1 can be a steel shell, and the busbar 3 can be a copper busbar, i.e., the lap joint 32 is a copper lap joint.

[0066] Since the outer diameter R1 of the lap joint 32, the inner diameter R2 of the open end face 11, and the outer diameter R3 of the open end face 11 satisfy R2 < R1 < R3, when the end cover 2 and the shell 1 are both steel and the busbar 3 is copper, the above setting causes the welded joint of the end cover 2, the shell 1, and the busbar 3 to form a steel-clad-copper metallurgical structure after welding, which mainly melts steel and a small amount of copper, realizing the steel cladding of the copper structure of the busbar 3 between the end cover 2 and the shell 1. This setting causes the melting ratio of copper during welding to be much lower than the melting ratio of steel, reducing the formation of cracks and pores of copper melting into the grain boundary of steel, thereby further improving the welding and sealing reliability of the whole.

[0067] In specific implementation, if the thickness of the lap joint 32 is too small, when the lap joint 32 is lapped on the open end face 11 of the shell 1, the lap joint 32 is prone to deformation, and since the battery cell 4 needs to conduct electricity to the power device outside the shell 1 through the busbar 3, if the thickness of the lap joint 32 is too small, it will cause the lap joint 32 to have a small flow area, thereby causing the busbar 3 to have poor flow capacity. However, if the thickness of the lap joint 32 is too large, it will cause the materials of the lap joint 32, the end cover 2, and the shell 1 to melt in a large proportion during welding, which is prone to cause welding pores and cracks, and cannot realize the metallurgical characteristics such as steel-clad-copper, affecting the structural strength of the battery.

[0068] Based on this, referring to FIG. 1, Figures 3 to 5 In some embodiments, the thickness h1 of the lap joint 32 in the first direction satisfies 0.1 mm ≤ h1 ≤ 0.5 mm.

[0069] The first direction here can be, for example, the up-down direction in Figure 3 The thickness h1 can be, for example, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, or 0.5 mm.

[0070] By setting the thickness of the lap joint 32 within the above range, not only can the deformation of the lap joint 32 be avoided to a certain extent, the reliability of the lapping is improved, the welding reliability and the structural strength after welding are ensured, but also the flow capacity of the busbar 3 is ensured.

[0071] Referring to FIG. 1, Figure 5 In some embodiments, the outer edge of the projection of the lap joint 32 on the open end face 11 is located inside the outer edge of the open end face 11.

[0072] That is, a gap 10 is formed between the outer edge of the lap portion 32 and the opening end face 11 of the shell 1. This facilitates the cladding effect of the shell 1 and the end cap 2 on the busbar 3 after the shell 1, the busbar 3, and the end cap 2 are welded and melted, thereby improving the welding reliability and the structural strength of the overall structure.

[0073] In some embodiments, the projected length b of the end cap 2 on the opening end face 11 and the projected length a of the lap portion 32 on the opening end face 11 can satisfy the following relationship:

[0074] b-a > 0.1 mm;

[0075] The projected length b here is specifically the dimension of the projection of the end cap 2 on the opening end face 11 along the left-right direction, and the projected length a is specifically the dimension of the projection of the lap portion 32 on the opening end face 11 along the left-right direction. Figure 5 Figure 5 For example, the difference between the projected length b of the end cap 2 and the projected length a of the lap portion 32 can be set to 0.15 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, or 0.3 mm.

[0076] This setting ensures the length of the end cap 2 corresponding to the position of the opening end face 11 of the shell 1, so that the end cap 2 can provide sufficient molten material during welding, and the material (such as steel) melted by the end cap 2 fills the gap 10 between the outer edge of the busbar 3 and the opening end face 11, thereby improving the cladding effect of the shell 1 and the end cap 2 on the busbar 3, such as forming a steel-clad copper metallographic structure, and improving the welding reliability and strength.

[0077] In some embodiments, continuing to refer to FIG. 2, in the first direction, the thickness h1 of the lap portion 32 and the thickness h2 of the end cap 2 at the position corresponding to the opening end face 11 satisfy: h1 / h2≤2 / 3. Figure 5

[0078] The thickness h1 is specifically the dimension of the lap portion 32 along the up-down direction, and the thickness h2 is specifically the dimension of the end cap 2 at the position corresponding to the opening end face 11 along the up-down direction. Figure 5 Figure 5

[0079] For example, h1 can be 0.1 mm and h2 can be 0.3 mm, for example, h1 can be 0.3 mm and h2 can be 0.5 mm, for example, h1 can be 0.5 mm and h2 can be 0.8 mm.

[0080] This setting can further ensure the thickness of the end cap 2, thereby ensuring that the end cap 2 provides sufficient molten material for cladding the end face of the busbar 3 during welding, thereby improving the welding reliability. ​​​​

[0081] Referring to Figure 6 In some embodiments, the end cover 2 has a bent portion 22 extending towards the housing 1, and the bent portion 22 is arranged outside the lap joint portion 32.

[0082] That is, the gap 10 between the outer edge of the lap joint portion 32 and the open end surface 11 of the housing 1 is filled by the bent portion 22, so that the housing 1 and the end cover 2 can cover the busbar 3 during welding, such as to achieve a steel covering copper metallurgical structure, thereby ensuring the welding effect and structural strength.

[0083] Referring to Figure 5 , Figure 6 and Figure 10 In some embodiments, a groove 321 is formed at the joint between the lap joint portion 32 and the disc body 31.

[0084] By arranging the groove 321, the busbar 3 can have a better stretching effect, which is convenient for adjusting the busbar 3 and is more conducive to welding operation. In addition, when the busbar 3 is a structure formed by stamping, the presence of the groove 321 is conducive to the flow of the busbar 3 blank, which can prevent burrs from being generated due to the accumulation of the blank, so as to prevent the burrs from piercing the surrounding components and affecting the performance of the battery.

[0085] Specifically, in some embodiments, in the first direction, the groove depth h3 of the groove 321 satisfies the following relationship:

[0086] h3≥0.1mm.

[0087] Wherein, the first direction is, for example, the up-down direction in Figure 10 The groove depth h3 is the size of the groove 321 in the up-down direction. Figure 10 For example, h3 can be 0.1mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, or 0.3mm.

[0088] By setting the groove depth of the groove 321 within the above range, the stretching effect of the busbar 3 is further improved, thereby further improving the convenience and reliability of welding, and burrs can be further prevented.

[0089] Referring to Figure 4 , Figure 5 and Figure 9 In some embodiments, in the first direction, the disc body 31 protrudes towards the inner cavity of the housing 1 relative to the lap joint portion 32, and the outer wall surface 310 of the disc body 31 and the lap joint portion 32 together form a first positioning portion 303 cooperating with the housing 1.

[0090] By making the disk body 31 protrude toward the inner cavity of the shell 1, it is convenient to weld the disk body 31 to the pole ear of the battery cell 4. At the same time, since the outer wall surface 310 of the disk body 31 and the overlapping portion 32 form a first positioning portion 303, when the overlapping portion 32 overlaps the open end surface 11 of the shell 1, the shell 1 and the busbar 3 can be positioned by the first positioning portion 303, avoiding the movement of the shell and the busbar 3 during welding and causing poor welding. That is, this arrangement improves the stability between the shell 1 and the busbar 3 during welding, and further improves the reliability and efficiency of welding.

[0091] Exemplarily, the first positioning portion 303 may be a positioning groove or a positioning notch, etc., to achieve positioning between the housing 1 and the busbar 3 .

[0092] Among them, if the inner diameter of the overlap portion 32 is too small relative to the inner diameter R2 of the opening end surface 11, the positioning between the housing 1 and the busbar 3 will be unstable when the overlap portion 32 overlaps the opening end surface 11, resulting in poor welding. However, if the inner diameter of the overlap portion 32 is too large, it will make it difficult to assemble the overlap portion 32 and the opening end surface 11, resulting in poor welding. Based on this, combined with Figure 3 、 Figure 4 、 Figure 5 and Figure 9 As shown, in some embodiments, the inner diameter R4 of the overlapping portion 32 and the inner diameter R2 of the opening end surface 11 satisfy the following relationship:

[0093] R2-0.1mm≤R4≤R2+0.1mm;

[0094] Among them, reference Figure 9 As shown, the inner diameter R4 of the overlap portion 32, i.e., the inner ring of the overlap portion 32, is Figure 9 Diameter dimension in the left-right direction.

[0095] This arrangement further ensures the positioning effect between the busbar 3 and the housing 1, thereby improving the welding effect and avoiding poor welding.

[0096] In some embodiments, the angle r between the outer wall surface 310 of the disk 31 and the horizontal plane satisfies: 80°<r<95°. Figure 5 As shown, the horizontal plane here can be specifically Figure 5 For example, the angle r can be 80°, 85°, 87.5°, 90°, or 95°.

[0097] By setting the outer wall surface 310 of the plate body 31 within the above-mentioned angle range, the smoothness and good positioning of the busbar 3 and the shell 1 during overlap are ensured, thereby ensuring the welding effect.

[0098] Reference Figure 4As shown, in some embodiments, the end cover 2 is formed with a second positioning part 21 matched with the disc body 31. Such arrangement enables the end cover 2 and the busbar 3 to be positioned through the second positioning part 21 when the end cover 2 is lapped on the busbar 3, thereby improving the relative stability between the end cover 2 and the busbar 3 during welding, and further improving the welding quality and the structural strength after welding.

[0099] Moreover, by positioning the end cover 2 and the busbar 3 through the second positioning part 21, and positioning the busbar 3 and the shell 1 through the first positioning part 303, the relative stability among the three is improved, and further the welding quality, the welding efficiency and the reliability are improved.

[0100] For example, the second positioning part 21 can be a positioning groove or a positioning notch, etc., to realize the positioning between the end cover 2 and the busbar 3.

[0101] With reference to Figures 5 to 9 As shown, in some embodiments, the disc body 31 can specifically include a connecting area 311 and a stretching area 312. The stretching area 312 is arranged outside the connecting area 311 along the circumferential ring of the connecting area 311, and the lapping part 32 is arranged outside the stretching area 312 along the circumferential ring of the stretching area 312.

[0102] Specifically, the stretching area 312 protrudes towards the direction of the inner cavity of the shell 1, and the outer wall surface 310 of the stretching area 312 and the lapping part 32 jointly form the above-mentioned first positioning part 303.

[0103] In specific implementation, the connecting area 311 can be welded with the tab of the battery cell 4 first, and then the lapping part 32, the shell 1 and the end cover 2 are welded together through one-time welding process.

[0104] In order to ensure the positioning effect between the busbar 3 and the shell 1, with reference to Figure 5 As shown, in some embodiments, along the first direction, the projection length h4 of the stretching area 312 on the shell 1 satisfies the following relationship:

[0105] h4≥0.2mm.

[0106] Wherein, the first direction is, for example, the up-down direction in Figure 5 The projection length h4 is the projection size of the stretching area 312 on the shell 1 along the up-down direction. For example, h4 can be 0.2mm, 0.22mm, 0.25mm, 0.3mm, 0.33mm, 0.35mm, 0.4mm, etc.

[0107] Such arrangement ensures the size of the stretching area 312 in the axial direction of the shell 1, thereby further ensuring the positioning effect between the busbar 3 and the shell 1, and further ensuring the stability of the lapping between the busbar 3 and the shell 1, and further ensuring the welding quality and the structural strength.

[0108] Further, with reference to Figures 5 to 9 , the busbar 3 can further include an elastic connecting portion 313, which has a spacing between the connecting region 311 and the stretching region 312 in a first direction, which is specifically the up-down direction in Figure 5 and Figure 9 . That is, the connecting region 311 and the stretching region 312 are not in the same plane. The connecting region 311 is connected to the stretching region 312 through the elastic connecting portion 313.

[0109] Such an arrangement makes the elastic adjustable space of the busbar 3 larger, so that after the connecting region 311 is welded with the battery cell 4, the busbar 3 can be stretched or the like to adjust the height of the busbar 3, so as to realize reliable welding between the busbar 3, the shell 1 and the end cover 2.

[0110] In specific implementation, if the total thickness of the busbar 3 is too small, the elastic adjustable range of the busbar 3 will be reduced; but if the total thickness of the busbar 3 is too large, the effective space utilization rate of the battery will be affected, and the battery will be too thick, thereby reducing the unit volume energy density of the battery. Based on this, with reference to Figure 9 , in some embodiments, in the first direction, the total thickness h of the busbar 3 satisfies the following relationship:

[0111] 0.5mm < h < 2mm;

[0112] wherein the first direction can be specifically the up-down direction in Figure 9 , such as the axial direction of the battery. The total thickness h of the busbar 3 here is the maximum thickness of the busbar 3 in the up-down direction.

[0113] For example, the total thickness h of the busbar 3 can be 0.55mm, 0.6mm, 0.7mm, 0.8mm, 1mm, 1.2mm, 1.25mm, 1.5mm, 1.7mm, 1.8mm, 1.9mm, 1.95mm.

[0114] By setting the total thickness of the busbar 3 in the above range, not only the elastic adjustable range of the busbar 3 is ensured, but also the welding effect of the busbar 3 is ensured, and the situation that the busbar 3 is too thick to affect the effective space utilization rate of the battery and reduce the unit volume energy density can be avoided.

[0115] In specific implementation, if the difference between the outer diameter and the inner diameter of the open end face 11 of the shell 1 is too small, that is, the width of the open end face 11 is too small, the difficulty of the lapping portion 32 lapping on the open end face 11 will be greatly increased; but if the width of the open end face 11 is too large, the weight of the battery will be increased. Based on this, with reference to Figures 3 to 5As shown, in some embodiments, the inner diameter R2 of the opening end face 11 and the outer diameter R3 of the opening end face 11 satisfy the following relationship:

[0116] 0.2mm≤R3-R2≤0.8mm;

[0117] By setting the difference between the outer diameter and the inner diameter of the opening end face 11 in the above range, it is ensured that the opening end face 11 has sufficient lap area to lap with the lap joint 32, and at the same time, the situation of excessive battery weight is avoided.

[0118] When the end cover 2 is a steel end cover, the shell 1 is a steel shell, and the busbar 3 is a copper busbar, the effective penetration depth of the metallographic structure formed by the welding of the end cover 2, the lap joint 32 and the shell 1 of the battery assembled by the above lap joint and one-time welding satisfies: effective penetration width > 0.15mm. The effective penetration width of the metallographic structure formed by the welding of the end cover 2, the lap joint 32 and the shell 1 satisfies: effective penetration width > 0.8mm. It can be seen that the welding joint of the end cover 2, the lap joint 32 and the shell 1 has high penetration width and penetration depth, and good welding strength and welding reliability are achieved.

[0119] The penetration depth is the depth of the molten pool, that is, the depth of the molten joint in the metal. The effective penetration depth is the depth of the joint between the steel shell and the steel end cover. The penetration width is the width of the molten joint in the metal.

[0120] The present embodiment also provides a battery for use in an electric device. The electric device can include, but is not limited to, an electric vehicle (e.g., a pure electric vehicle, a hybrid electric vehicle, an electric bicycle, etc.).

[0121] The battery of the present embodiment has the same specific structure and implementation principle as the battery provided in the above embodiments and can bring the same or similar technical effects. Details are not repeated here, and the description of the above embodiments can be referred to.

[0122] In this article, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixedly connected, it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances. In addition, the terms "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the application.

[0123] In this article, such as "first" and "second" and the like relationship terms are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0124] The above is only the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement and the like made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A battery, characterized by, The battery case (1), the end cover (2) and the busbar (3) are provided. The busbar (3) comprises a disc body (31) and a lap joint (32) arranged on the outer side of the disc body (31) along the circumferential direction of the disc body (31). The battery case (1) has an opening at one end in the first direction, at least part of the lap joint (32) is lapped on the opening end surface (11) of the battery case (1), the end cover (2) is arranged on the side of the busbar (3) away from the battery case (1), and the lap joint (32) and the battery case (1) and the lap joint (32) and the end cover (2) are welded. Wherein, the outer diameter R1 of the lap joint (32), the inner diameter R2 of the opening end surface (11) and the outer diameter R3 of the opening end surface (11) satisfy: R2 < R1 < R3.

2. The battery of claim 1, wherein, The thickness h1 of the lap joint (32) in the first direction satisfies: 0.1mm ≤ h1 ≤ 0.5mm.

3. The battery of claim 1, wherein, The outer edge of the projection of the lap joint (32) on the opening end surface (11) is located inside the outer edge of the opening end surface (11). And / or, the projection length b of the end cover (2) on the opening end surface (11) and the projection length a of the lap joint (32) on the opening end surface (11) satisfy: b-a>0.1mm; And / or, in the first direction, the thickness h1 of the lap joint (32) and the thickness h2 of the end cover (2) at the corresponding position of the opening end surface (11) satisfy: h1 / h2 ≤ 2 / 3.

4. The battery of claim 1, wherein, The outer edge of the projection of the lap joint (32) on the opening end surface (11) is located inside the outer edge of the opening end surface (11). The end cover (2) has a bending part (22) extending towards the battery case (1), and the bending part (22) surrounds the outside of the lap joint (32).

5. The battery of claim 1, wherein, The joint of the lap joint (32) and the disc body (31) is formed with a groove (321).

6. The battery of claim 5, wherein, In the first direction, the groove depth of the groove (321) satisfies h3 ≥ 0.1mm.

7. The battery of claim 1, wherein, In the first direction, the disc body (31) protrudes towards the inner cavity of the battery case (1) relative to the lap joint (32), and the outer wall surface (310) of the disc body (31) and the lap joint (32) together form a first positioning part (303) matched with the battery case (1).

8. The battery of claim 7, wherein, The inner diameter R4 of the lap joint (32) and the inner diameter R2 of the opening end surface (11) satisfy: R2-0.1mm ≤ R4 ≤ R2+0.1mm; And / or, the angle r between the outer wall surface (310) of the disc body (31) and the horizontal plane satisfies: 80° < r < 95°; And / or, the end cover (2) is formed with a second positioning part (21) matched with the disc body (31).

9. The battery of claim 7, wherein, The disc body (31) comprises a connecting area (311) and a stretching area (312), the stretching area (312) is arranged outside the connecting area (311) along the circumferential ring of the connecting area (311), and the lap joint (32) is arranged outside the stretching area (312) along the circumferential ring of the stretching area (312); The stretching area (312) protrudes towards the direction of the inner cavity of the shell (1), and the outer wall surface of the stretching area (312) and the lap joint (32) jointly form the first positioning part (303); In the first direction, the projection length h4 of the stretching area (312) on the shell (1) satisfies: h4≥0.2mm.

10. The battery of claim 1, wherein, The inner diameter R2 of the open end surface (11) and the outer diameter R3 of the open end surface (11) satisfy: 0.2mm≤R3-R2≤0.8mm; And / or, in the first direction, the total thickness h of the busbar (3) satisfies: 0.5mm<h<2mm; And / or, the disc body (31) comprises a connecting area (311), an elastic connecting part (313) and a stretching area (312); the stretching area (312) is arranged outside the connecting area (311) along the circumferential ring of the connecting area (311), the lap joint (32) is arranged outside the stretching area (312) along the circumferential ring of the stretching area (312), and in the first direction, the connecting area (311) and the stretching area (312) have a spacing, and the connecting area (311) is connected with the stretching area (312) through the elastic connecting part (313).

11. The battery of any one of claims 1 to 10, wherein, The material of the end cover (2) is the same as that of the shell (1), and different from that of the busbar (3).

12. The battery of claim 11, wherein, The end cover (2) is a steel end cover, the shell (1) is a steel shell, and the busbar (3) is a copper busbar.

13. The battery of claim 12, wherein, The effective penetration depth of the metallographic structure formed by the welding of the end cover (2), the lap joint (32) and the shell (1) satisfies: effective penetration depth>0.15mm; And / or, the effective fusion width of the metallographic structure formed by the welding of the end cover (2), the lap joint (32) and the shell (1) satisfies: effective fusion width>0.8mm.

14. An electrical device, characterized by The battery comprises the battery as claimed in any one of claims 1 to 13. The battery comprises the battery as claimed in any one of claims 1 to 13.

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