Battery

Abstract

The utility model relates to the technical field of batteries, and discloses a battery which comprises a shell, an end cover, a roll core and a confluence plate structure, and the roll core is arranged in the shell; the confluence plate structure comprises a first welding unit suitable for being connected with a shell and / or an end cover in a welded mode; the second welding unit comprises a second welding unit body and a connecting piece formed by at least partially extending the second welding unit body; the second welding unit body is suitable for being welded with a roll core; the connecting piece is connected between the first side edge of the first welding unit and the second side edge of the second welding unit body; and the connecting piece is locally thinned to form a fusing part. According to the battery provided by the embodiment of the utility model, the fusing part is arranged to form the diversion blocking region, so that the capability of current passing through the diversion blocking region is reduced, the resistance is increased, the current is seriously heated at the diversion blocking region, and the fusing part can be fused due to local high temperature when the current is too large, so that the situation that the current is too large to generate heat and burn is avoided; and the safety is improved.

Description

TECHNICAL FIELD

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

[0002] With the wide application of lithium battery, the safety performance requirement of battery monomer is higher and higher.

[0003] In the application process of lithium battery, internal short circuit can be caused by some factors, and then current overlarge heating combustion is easily caused, and certain security risks exist. UTILITY MODEL CONTENT

[0004] Therefore, the utility model provides a battery to solve the problem that lithium battery is prone to security risks caused by internal short circuit.

[0005] The utility model provides a battery, which comprises:

[0006] The shell, the end cover, the roll core and the bus bar structure, and the roll core is arranged in the shell.

[0007] The bus bar structure comprises:

[0008] The first welding unit is suitable for welding connection with the shell and / or the end cover.

[0009] The second welding unit comprises a second welding unit body and a connecting piece formed by the second welding unit body at least partially extending.

[0010] The second welding unit body is suitable for welding connection with the roll core.

[0011] The connecting piece is connected between the first side edge of the first welding unit and the second side edge of the second welding unit body.

[0012] The connecting piece is partially thinned to form a fuse part.

[0013] The battery provided by the embodiment of the utility model has the fuse part to form a flow resistance area, so that the current capacity passing through the area is reduced, the resistance is increased, the current is seriously heated at the area, and the fuse part can be fused due to local high temperature when the current is too large, so that the situation of current overlarge heating combustion is avoided, and the safety is improved.

[0014] In an optional embodiment, the first welding unit has a clearance hole formed in the middle part, and the second welding unit is arranged inside the clearance hole.

[0015] The first welding unit has a plurality of first side edges arranged on the inner side surface of the clearance hole, the second welding unit has a plurality of second side edges arranged on the outer side surface facing the first welding unit, and the plurality of first side edges and the plurality of second side edges correspond one by one.

[0016] Each first side edge is connected to a corresponding second side edge via at least one connecting piece.

[0017] In an optional embodiment, the connecting piece is continuously arranged around the second side edge.

[0018] In an optional embodiment, the connecting piece is continuously arranged around the second side edge; the fuse portion is formed in the connecting piece and arranged in a continuous ring.

[0019] In an optional embodiment, the connecting piece comprises a plurality of connecting segments, the plurality of connecting segments are arranged at intervals around the circumference of the second side edge; each connecting segment is formed with a fuse portion.

[0020] In an optional embodiment, the length of the connecting piece from the first side edge to the second side edge is b, the distance from the edge close to the first side edge side of the fuse portion to the first side edge is a, which satisfies: b≥a+1.5mm; and satisfies: a>2mm.

[0021] Beneficial effect: Because the length of b will affect the distance of the fuse portion to the welding area of the inner and outer sides, if the size of b is too small, it is easy to be affected by the internal stress of the second welding unit body and the welding heat radiation of the first welding unit, which will affect the stress of the connecting piece, and further easily lead to the decline of the fusing capacity of the fuse portion. On the contrary, if the size of b is too large, it will affect the projection area S of the first welding unit, so that the welding area of the second welding unit is too small, the resistance from the core to the negative bus bar is too large, and further cause the internal resistance of the battery to be too large.

[0022] In an optional embodiment, the width of the fuse portion is c, which satisfies: c≤0.5mm.

[0023] Beneficial effect: If the width c of the fuse portion is too large, it will affect the size of the total length b of the connecting piece, and further affect the welding area of the second welding unit, and the width of the fuse portion being too large is more likely to cause the overall rigidity to decline, resulting in fatigue fracture.

[0024] In an optional embodiment, the length of the fuse portion is W4, the diameter of the bus bar structure is W3, which satisfies: 16mm≤W4≤W3.

[0025] Beneficial effect: When W4 is too small, the minimum overcurrent capacity of the whole battery will not meet the general market demand, so it is necessary to limit the lower limit of W4.

[0026] In an optional embodiment, along the axis direction of the accommodation hole, the recess depth of the fuse portion is h1, the thickness of the second welding unit body and the connecting piece is h3, which satisfies: 0.3·h3≤h1≤0.8·h3.

[0027] Beneficial effects: when h1 is too large, that is, the thickness of the connecting piece at the position of the melting portion is too thin, the whole structure is prone to brittle fracture at the position of the connecting piece, and the overcurrent capacity is greatly reduced; when h1 is too small, the melting effect of limiting overcurrent that the connecting piece at the position of the melting portion should play will fail.

[0028] In an alternative embodiment, the second welding unit body is staggered with the first welding unit along the axis direction of the accommodation hole; and the connecting piece is arranged obliquely relative to the axis direction of the accommodation hole and connected between the second welding unit body and the first welding unit.

[0029] In an alternative embodiment, the second welding unit body and the connecting piece are integrally formed; the second welding unit body and the connecting piece are made of the same material.

[0030] In an alternative embodiment, the first welding unit and the second welding unit are integrally formed by a composite material, or are weldedly connected.

[0031] The first welding unit and the second welding unit are made of different materials.

[0032] In an alternative embodiment, the material of the first welding unit includes steel, and the material of the second welding unit includes copper.

[0033] In an alternative embodiment, the extension direction of the melting portion is parallel to the extension direction of the first side edge and / or the second side edge.

[0034] In an alternative embodiment, the first welding unit includes a stretching plane portion parallel to the plane where the end face of the winding core is located, and a flange portion folded from the stretching plane portion to the side away from the end face of the winding core. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0036] Figure 1 It is a schematic diagram of the battery of the present application;

[0037] Figure 2 It is a top view of the busbar structure of the present application Figure 1 ;

[0038] Figure 3 It is a top view of the busbar structure of the present application Figure 2 ;

[0039] Figure 4 is a partial enlarged view of Figure 3 ;

[0040] Figure 5 is a sectional view of the busbar structure of the utility model;

[0041] Figure 6 is a sectional view of the battery of the utility model;

[0042] Figure 7 is a partial enlarged view of Figure 6 ;

[0043] Figure 8 is an exploded schematic view of another busbar structure of the utility model.

[0044] BRIEF DESCRIPTION OF DRAWINGS

[0045] 1, busbar structure; 2, shell; 3, end cover; 4, winding core;

[0046] 11, first welding unit; 111, flange portion; 112, tensile flat portion; 113, accommodation hole; 114, first side edge;

[0047] 12, second welding unit; 121, connecting piece; 1211, fusing portion; 122, second welding unit body; 124, second side edge. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0049] In the description of the utility model, it should be explained that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0050] In the description of the utility model, it is necessary to explain that, unless there is definite stipulation and limitation, the terms "mount", "connect", "connect" should be understood in a broad sense, for example, it can be fixed connection, or it can be detachable connection, or it can be integrally connected, it can be mechanical connection, or it can be electrical connection, it can be directly connected, or it can be indirectly connected through intermediate medium, it can be the communication inside two elements, for ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0051] In addition, the technical features involved in the different embodiments of the utility model described below can be combined with each other as long as there is no conflict between them.

[0052] In the application process of lithium battery, internal short circuit may be caused by some factors, and then the current is too large to heat and burn, which has certain safety hazard. In order to reduce the occurrence of internal short circuit of lithium battery, it is a feasible measure to design corresponding fuse structure in structural part. The fuse structure is that when the current exceeds the specified value for a period of time, the heat generated by itself makes the fuse melt, so that the circuit is disconnected.

[0053] Taking cylindrical lithium battery as an example, its structure includes roll core, shell, end cover and pole provided on the end cover. In order to facilitate the current output of the roll core, positive and negative bus bars are usually provided, wherein the positive bus bar is used to connect the roll core and the pole, so that the pole is positively charged, and the negative bus bar is used to connect the roll core, the shell and the end cover, so that the shell and the end cover are used as negative electrode. Among them, the bus bar as a flow guide medium plays an important role in the structure of the battery core, and the fuse structure is arranged at the position of the bus bar which plays the role of connection and conduction, which is more convenient to maintain the integrity of other structures and is convenient for processing.

[0054] However, the fuse structure used in the related art often has poor stability of the fusing effect, and cannot make the fusing current of each battery monomer uniform, which still has certain safety hazard to a certain extent.

[0055] The battery provided by the embodiment of the utility model has the advantages that the thinning fusing part is arranged on the bus bar structure, the positions formed by the thinning fusing part are mostly linear segments or regular shapes, the setting of arc segments or irregular shapes is reduced, so that it is more conducive to make the fusing current of the thinning fusing part uniform, avoid the situation that the fusing effect has poor stability, and reduce the safety hazard.

[0056] The embodiments of the utility model will be described below in combination with Figures 1 to 8 , the description of the embodiments of the utility model.

[0057] According to the embodiment of the utility model, a kind of battery is provided, comprising:

[0058] The shell 2, the end cover 3, the winding core 4 and the busbar structure 1, the winding core 4 is arranged in the shell 2;

[0059] The busbar structure 1 comprises:

[0060] The first welding unit 11 is adapted to be welded with the shell 2 and / or the end cover 3;

[0061] The second welding unit 12 comprises a second welding unit body 122 and a connecting piece 121 formed by the second welding unit body 122 at least partially extending;

[0062] The second welding unit body 122 is adapted to be welded with the winding core 4;

[0063] The connecting piece 121 is connected between the first side edge 114 of the first welding unit 11 and the second side edge 124 of the second welding unit body 122;

[0064] The connecting piece 121 is partially thinned to form a fuse portion 1211.

[0065] The busbar structure 1 is used to lead out the current of the winding core 4 to the outside; the shell 2 serves as a container of the winding core 4, and bears the functions of sealing the winding core 4 and the electrolyte and resisting external force deformation, and the material of the shell 2 is usually stainless steel or low-carbon steel; the end cover 3 is a cell end cover, and also bears the functions of sealing the winding core and the electrolyte and resisting external force deformation, and the material of the end cover 3 is also stainless steel or low-carbon steel.

[0066] In some examples, the materials of the shell 2, the end cover 3 and the first welding unit 11 are the same, all being stainless steel or low-carbon steel. The first welding unit 11 is lapped on the shell 2, and the end cover 3 abuts against the other side of the first welding unit 11, so that the yield of welding, especially laser welding, can be greatly improved.

[0067] The second welding unit body 122 contacts the tab of the winding core 4, and the second welding unit body 122 and the winding core tab are also made of the same material, so that the yield of welding at this position is also improved.

[0068] The connecting piece 121 is a part of the second welding unit 12, and serves as a connecting piece of the second welding unit body 122 and the first welding unit 11. The connecting piece 121 is further partially thinned to form a fuse portion 1211. The fuse portion 1211 forms a flow resistance area by the thinning of the thickness, and the cross section of the area is reduced, so that the current capacity of the area is reduced and the resistance is increased, the current generates a lot of heat at this position, and then a local high temperature is formed to fuse.

[0069] The battery provided by the embodiment of the utility model, by setting the fusing part 1211 to form the flow resistance area, the current capacity of the area is reduced, the resistance is increased, the current is seriously heated at the area, and when the current is too large, the fusing part 1211 can be fused due to local high temperature, thereby avoiding the situation of too large current heating and burning, and improving the safety.

[0070] In addition, in the embodiment, the first side edge 114 and the second side edge 124 are arranged in parallel and spaced apart, and the first side edge 114 and the second side edge 124 are both configured as non-arc surfaces.

[0071] The battery provided by the embodiment of the utility model, by setting the fusing part 1211 on the connecting piece 121 of the bus bar structure, the connecting piece 121 is connected between the first side edge 114 of the first welding unit 11 and the second side edge 124 of the second welding unit body 122, the first side edge 114 and the second side edge 124 are arranged in parallel and spaced apart, and the first side edge 114 and the second side edge 124 are both configured as non-arc surfaces; so that the shape of the connecting piece 121 is more regular, for example, a rectangular sheet structure, and the shape of the corresponding fusing part 1211 is more regular, for example, a straight line segment, thereby avoiding the fusing part 1211 adopting an irregular line segment form, and more conducive to making the fusing current of the fusing part 1211 uniform, avoiding the situation that the fusing effect stability is poor, and reducing the security risk.

[0072] As an option, the shape of the connecting piece 121 can be a rectangular sheet structure, or a trapezoidal sheet structure, etc. so that the cross-sectional size of each position of the fusing part 1211 remains consistent or remains linearly changed.

[0073] The fusing capacity of the fusing part 1211 can be adjusted by reducing the thickness according to the demand, improving the adaptability of different models of batteries, and greatly increasing the safety of the battery.

[0074] In addition, the bus bar structure of the embodiment is specifically a bus bar structure arranged on the negative electrode. Since the bus bar pole and the tab on the positive electrode position are completely matched, the disconnection cannot be realized after fusing, so it is not convenient to set the connecting piece 121 as a connecting bridge, and further, it is also not convenient to form the fusing part 1211 with consistent size.

[0075] The second welding unit 12 is partially extended to form a connecting piece 121, and a fuse portion 1211 is further arranged on the connecting piece 121. The advantage of this arrangement is that, through welding with the second welding unit body 122, the current can be fully conducted in the second welding unit body 122, and then the current in the second welding unit body 122 needs to be fully conducted through the fuse portion 1211, so that the real overcurrent capacity can be maximally reflected. If the fuse portion 1211 is located at the center of the second welding unit body 122, a part of the current will not pass through the fuse portion 1211 but directly flow to the shell 2, so that the overcurrent capacity level cannot be reflected.

[0076] In some embodiments, in combination Figure 2 As shown, the first welding unit 11 is formed with a through hole 113 in the middle, and the second welding unit 12 is arranged inside the through hole 113.

[0077] The first welding unit 11 is provided with a plurality of first side edges 114 around the inner side surface of the through hole 113, and the second welding unit 12 is provided with a plurality of second side edges 124 facing the outer side surface of the first welding unit 11, and the plurality of first side edges 114 and the plurality of second side edges 124 correspond one-to-one.

[0078] Each first side edge 114 is connected to the corresponding second side edge 124 via at least one connecting piece 121.

[0079] The second welding unit 12 is arranged inside the through hole 113, that is, along the axis direction of the through hole 113, the projection of the second welding unit 12 is located within the range of the through hole 113.

[0080] In an example, in combination Figure 2 As shown, the first welding unit 11 is provided with four first side edges 114 around the inner side surface of the through hole 113, and the second welding unit 12 is provided with four second side edges 124 facing the outer side surface of the first welding unit 11. The four second side edges 124 can be arranged to form a quadrilateral, or a transition edge structure is arranged between adjacent two second side edges 124.

[0081] As an implementation form, in combination Figure 3 As shown, the connecting piece 121 includes a plurality of connecting segments, and the plurality of connecting segments are arranged at intervals around the circumference of the second side edge 124; each connecting segment is formed with a fuse portion 1211.

[0082] By arranging the plurality of connecting segments around the circumference of the second side edge 124 to be spaced from each other, the second welding unit body 122 can only be connected to the first welding unit 11 through the connecting piece 121, and the fuse portion 1211 is formed at each connecting segment. Further, after the fuse is broken, the possibility of the second welding unit body 122 and the first welding unit 11 continuing to be overlapped can be minimized, and the safety performance is improved.

[0083] In the embodiment, the first welding unit 11 is arranged on the inner side of the accommodation hole 113, and the second welding unit 12 is arranged on the outer side of the accommodation hole 113. Figure 2 As shown in the figure, the plurality of connecting segments are uniformly arranged around the inner side of the accommodation hole 113.

[0084] For example, the busbar structure of the embodiment is applied to a cylindrical battery, the outer periphery of the first welding unit 11 is circular, and the inner side of the accommodation hole 113 is polygonal, which can be a polygonal structure of axial symmetry. Correspondingly, the outer peripheral edge of the second welding unit 12 is also polygonal, which can be a polygonal structure of axial symmetry.

[0085] By uniformly distributing the connecting piece 121 around the inner side of the accommodation hole 113, the overcurrent capacity of each connecting piece 121 is more balanced. This is conducive to making the fuse current of the fuse portion 1211 uniform.

[0086] As another implementation form, in combination with Figure 8 As shown in the figure, the connecting piece 121 can also be arranged continuously around the second side edge 124; and the fuse portion 1211 is formed in the connecting piece 121 and arranged in a continuous ring shape.

[0087] By arranging the connecting piece 121 continuously around the second side edge 124, the connection strength between the second welding unit body 122 and the first welding unit 11 is improved.

[0088] Further, the fuse portion 1211 is formed in the connecting piece 121 and arranged in a continuous ring shape; so that the fuse portion 1211 can form a fuse due to local high temperature, and then disconnect the connection between the second welding unit body 122 and the first welding unit 11, avoid the situation of excessive current heating and burning, and improve the safety.

[0089] In some embodiments, in combination with Figure 3 As shown in the figure, the minimum distance between the outer periphery of the first welding unit 11 and the inner side of the accommodation hole 113 is w1, which satisfies: w1≥2mm.

[0090] Because the high temperature caused by the welding of the first welding unit 11 and the shell 2 can easily deform or even disconnect the weak part of the welding area, a certain safety distance needs to be set. In order to ensure that there is a certain interval between the inner side of the accommodation hole 113 and the high-temperature welding area, and avoid deformation of the first welding unit 11 during welding.

[0091] In some embodiments, in combination Figure 3 As shown, along the axis direction of the accommodation hole 113, the projection area of the first welding unit 11 is S1, and the total projection area of the busbar structure is S0, which satisfies: 1 / 2·S0≤S1≤9 / 10·S0.

[0092] The axis direction of the accommodation hole 113 can be the height direction of the battery.

[0093] When the S1 area is too small, the welding area of the second welding unit 12 inside will be too small, the resistance from the core 4 to the negative busbar will be too large, and thus the internal resistance of the battery will be too large. When the S1 area is too large, the size of w1 of the first welding unit 11 will be affected, and thus poor welding is easily caused.

[0094] In some embodiments, in combination Figure 4 As shown, the length of the connecting piece 121 from the first side edge 114 to the second side edge 124 is b, and the distance from the edge of the fuse portion 121 close to the first side edge 114 to the first side edge 114 is a, which satisfies: b≥a+1.5mm; and satisfies: a>2mm.

[0095] Because the length of b will affect the distance from the fuse portion 1211 to the welding area of the inner and outer sides, if the size of b is too small, the connecting piece 121 will be easily affected by the stress inside the second welding unit body 122 and the welding heat radiation of the first welding unit 11, and thus the stress on the connecting piece 121 will be affected, and the fuse capability of the fuse portion 1211 will be easily reduced. Conversely, if the size of b is too large, the projection area S1 of the first welding unit 11 will be affected, and thus the welding area of the second welding unit 12 will be too small, the resistance from the core 4 to the negative busbar will be too large, and thus the internal resistance of the battery will be too large.

[0096] In addition, if the distance of a is too small, when the second welding unit 12 and the first welding unit 11 are connected by welding or the like, the heat radiation generated will easily cause stress concentration at the fuse portion 1211, and thus the fuse will be unstable.

[0097] In some embodiments, in combination Figure 4 As shown, the width of the fuse portion 1211 is c, which satisfies: c≤0.5mm.

[0098] Here, the width c of the fuse portion 1211 can be the distance between the edge of the fuse portion 1211 close to the first side edge 114 and the edge of the fuse portion 1211 close to the second side edge 124.

[0099] If the width c of the melting portion 1211 is too large, the overall length b of the connecting piece 121 will be affected, and the welding area of the second welding unit 12 will also be affected. In addition, if the width c of the melting portion 1211 is too large, the overall rigidity will be reduced, and the deformation fatigue fracture will be caused.

[0100] In some embodiments, in combination Figure 4 As shown in the figure, the length of the melting portion 1211 is W4, and the diameter of the busbar structure is W3, and the following condition is met: 16mm≤W4≤W3.

[0101] It should be noted that when the extension direction of the melting portion 1211 is parallel to the extension direction of the first side edge and / or the second side edge, the length W4 of the melting portion 1211 is the width of the connecting piece 121.

[0102] When the melting portion 1211 is a straight line segment, and the extension direction of the melting portion 1211 is not parallel to the extension direction of the first side edge or the second side edge, the length W4 of the melting portion 1211 is the length of the straight line segment formed by the extension of the melting portion 1211.

[0103] When the melting portion 1211 is a non-straight line segment, the length W4 of the melting portion 1211 is the length of the melting portion 1211 along its extension path. For example, in some embodiments, the shape of the melting portion 1211 can be circular, square, etc.

[0104] When W4 is too small, the minimum overcurrent capacity of the overall battery cell will not meet the general market demand, and therefore the lower limit of W4 needs to be limited.

[0105] In some embodiments, in combination Figure 5 As shown in the figure, the maximum distance between the outer circumferential surface of the first welding unit 11 and the inner side surface of the accommodation hole 113 is W2, and the diameter of the busbar structure is W3, and the following condition is met: 8%·W3≤W2≤15%·W3.

[0106] When W2 is too small, the welding heat radiation when the first welding unit 11 is overlapped with the shell will cause a thermal effect on the contact port of the first welding unit 11 and the second welding unit 12. When W2 is too large, the welding area between the second welding unit body 122 and the winding core 4 will be too small, and the overcurrent capacity of the winding core 4 and the negative busbar will be reduced.

[0107] In some embodiments, in combination Figure 7 As shown in the figure, along the axis direction of the accommodation hole 113, the thickness of the first welding unit 11 is h2, and the thickness of the second welding unit 12 is h3, and the following condition is met: 0.2mm≤h3≤h2≤0.5mm.

[0108] When h2<0.2mm or h3<0.2mm, the busbar structure is too thin, the whole busbar structure is easy to deform, causing insufficient rigidity, and the too thin thickness will cause insufficient current carrying capacity, causing serious heating and even melting. When h2>0.5mm or h3>0.5mm, the structure is too rigid, which affects the smooth assembly and reduces the welding yield.

[0109] When h3>h2, the current carrying capacity of the first welding unit 11 is less than that of the second welding unit body 122, which will cause heating at the contact surface of the first welding unit 11 and the end cover 3, and there is a certain safety hazard.

[0110] For example, in the present embodiment, the value of h3 can be 0.2mm or 0.3mm or 0.4mm or 0.5mm, etc., or the interval range formed by any two of the above values. The value of h2 can be 0.2mm or 0.3mm or 0.4mm or 0.5mm, etc., or the interval range formed by any two of the above values.

[0111] In some embodiments, in combination with Figure 7 As shown, along the axis direction of the accommodation hole 113, the recess depth of the melting portion 1211 is h1, the thickness of the second welding unit body 122 and the connecting piece 121 is h3, and 0.3·h3≤h1≤0.8·h3 is satisfied.

[0112] When h1 is too large, that is, the thickness of the connecting piece 121 at the position of the melting portion 1211 is too thin, the whole structure is easy to break at the position of the connecting piece 121, and the current carrying capacity is greatly reduced; when h1 is too small, the melting effect of limiting current of the connecting piece 121 at the position of the melting portion 1211 will be invalid.

[0113] In some embodiments, in combination with Figure 7 As shown, along the axis direction of the accommodation hole 113, the second welding unit body 122 and the first welding unit 11 are staggered; and the connecting piece 121 is inclined relative to the axis direction of the accommodation hole 113 and connected between the second welding unit body 122 and the first welding unit 11.

[0114] It should be noted that, along the axis direction of the displacement hole 113, the second welding unit body 122 is staggered with the first welding unit 11; that is, the second welding unit body 122 and the first welding unit 11 are not in the same plane, and there is a height difference between the two. Thus, the second welding unit body 122 can be in full contact with the end face of the core 4, ensuring the welding effect, while ensuring that the second welding unit body 122 does not contact the end cover 3 and the shell 2; and the first welding unit 11 can form good contact with the end cover 3 and the shell 2, without contacting the end face of the core 4; thus, after the fuse portion 1211 is fused, the circuit is broken.

[0115] In some embodiments, the second welding unit body 122 is integrally formed with the connecting piece 121; the second welding unit body 122 and the connecting piece 121 are made of the same material.

[0116] In some embodiments, the first welding unit 11 and the second welding unit 12 are integrally formed of a composite material, or are welded together.

[0117] The first welding unit 11 and the second welding unit 12 are made of different materials.

[0118] In some embodiments, the material of the first welding unit 11 includes steel, and the material of the second welding unit 12 includes copper.

[0119] Since the busbar structure of the present embodiment is composed of two parts of the first welding unit 11 and the second welding unit 12, wherein the first welding unit 11 is made of steel, and the second welding unit 12 is made of copper. Correspondingly, since the shell 2 and the end cover 3 are made of steel, the first welding unit 11 can be sealed and welded with the shell 2 and the end cover 3, which are made of the same material, so that the sealing reliability is greatly enhanced. At the same time, the tab of the core 4 is made of copper, so that the area of the busbar structure and the core 4 welded together is also welded by the same material, so that the yield of welding is increased. The electrical conduction and the overall stability are realized.

[0120] The steel material of the first welding unit 11 can specifically be stainless steel or low-carbon steel or steel plated with nickel, etc.

[0121] The copper material of the second welding unit 12 can specifically be red copper or copper plated with nickel, etc.

[0122] Since the busbar structure of the present embodiment contains two different materials, in order to realize the forming of the first welding unit 11 and the second welding unit 12, the composite material can be integrally formed, and the busbar structure composed of two different materials inside and outside can be formed by direct stretching of the composite material. The first welding unit 11 and the second welding unit 12 composed of two different materials can also be connected by welding.

[0123] In some embodiments, the extension direction of the fusing portion 1211 is parallel to the extension direction of the first side edge and / or the second side edge.

[0124] In some embodiments, the first welding unit 11 is welded to the housing 2 and the end cover 3. Figure 5 As shown, the first welding unit 11 includes a stretching plane portion 112 parallel to the plane in which the end face of the winding core 4 is located, and a flange portion 111 folded by the stretching plane portion 112 towards the side away from the end face of the winding core 4.

[0125] The position where the first welding unit 11 is welded to the housing 2 and the end cover 3 connects the components by means of mutual fusion, forms a seal of the housing, and conducts the electric current of the negative electrode to the outside of the housing.

[0126] The stretching plane portion 112 is a main body portion, which can be in a plane form, and forms an included angle of about 90° with the flange portion 111, so that the busbar structure 1 and the housing 2 can be well fitted and fixed.

[0127] Obviously, the above embodiments are only examples for clearly illustrating, but not limit the embodiments. Although the embodiments of the present application are described in conjunction with the drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations all fall within the scope of the present application.

Claims

1. A battery, characterized in that, include: The housing (2), end cap (3), core (4) and manifold structure (1) are provided, wherein the core (4) is disposed inside the housing (2); The busbar structure (1) includes: The first welding unit (11) is adapted to be welded to the housing (2) and / or end cap (3); The second welding unit (12) includes a second welding unit body (122) and a connector (121) formed by at least a partial extension of the second welding unit body (122); The second welding unit body (122) is adapted to be welded to the core (4); The connector (121) is connected between the first side edge (114) of the first welding unit (11) and the second side edge (124) of the second welding unit body (122); The connector (121) is partially thinned to form a fusible portion (1211).

2. The battery according to claim 1, characterized in that, The first welding unit (11) has a clearance hole (113) formed through the middle, and the second welding unit (12) is disposed inside the clearance hole (113); The first welding unit (11) is provided with a plurality of first side edges (114) around the inner side of the relief hole (113), and the second welding unit (12) is provided with a plurality of second side edges (124) facing the outer side of the first welding unit (11), and the plurality of first side edges (114) and the plurality of second side edges (124) correspond one-to-one; Each of the first side edges (114) is connected to the corresponding second side edge (124) via at least one of the connectors (121).

3. The battery according to claim 1, characterized in that, The connector (121) is continuously arranged around the second side edge (124); the fusible part (1211) is formed on the connector (121) and is arranged in a continuous ring.

4. The battery according to claim 1, characterized in that, The connector (121) includes a plurality of connecting segments, which are circumferentially spaced from each other around the second side edge (124); each connecting segment is formed with the fusible portion (1211).

5. The battery according to claim 1, characterized in that, The length of the connector (121) from the first side edge (114) to the second side edge (124) is b, and the distance from the edge of the fuse (1211) near the first side edge (114) to the first side edge (114) is a, satisfying: b≥a+1.5mm; and satisfying: a>2mm.

6. The battery according to claim 1, characterized in that, The width of the fused portion (1211) is c, which satisfies: c≤0.5mm.

7. The battery according to claim 1, characterized in that, The length of the fuse section (1211) is W4, and the diameter of the busbar structure is W3, satisfying: 16mm≤W4≤W3.

8. The battery according to claim 2, characterized in that, Along the axial direction of the relief hole (113), the recess depth of the fusion portion (1211) is h1, and the thickness of the second welding unit body (122) and the connector (121) is h3, satisfying: 0.3·h3≤h1≤0.8·h3.

9. The battery according to claim 2, characterized in that, Along the axial direction of the clearance hole (113), the second welding unit body (122) and the first welding unit (11) are staggered; and the connector (121) is inclined relative to the axial direction of the clearance hole (113) and connected between the second welding unit body (122) and the first welding unit (11).

10. The battery according to claim 1, characterized in that, The second welding unit body (122) and the connector (121) are integrally formed; the second welding unit body (122) and the connector (121) are made of the same material.

11. The battery according to claim 10, characterized in that, The first welding unit (11) and the second welding unit (12) are integrally formed from composite materials or welded together; The first welding unit (11) and the second welding unit (12) are made of different materials.

12. The battery according to claim 11, characterized in that, The first welding unit (11) is made of steel, and the second welding unit (12) is made of copper.

13. The battery according to claim 1, characterized in that, The extension direction of the fused portion (1211) is parallel to the extension direction of the first side edge and / or the second side edge.

14. The battery according to claim 1, characterized in that, The first welding unit (11) includes a stretching plane portion (112) parallel to the plane of the end face of the core (4), and a flange portion (111) folded from the stretching plane portion (112) toward the side away from the end face of the core (4).

Images