Battery connecting piece

Abstract

The utility model discloses a battery connecting piece. The battery connecting piece comprises a connecting piece body, a pole connecting area and a tab connecting area which are respectively connected with a pole and a tab are arranged on the connecting piece body, at least one first groove is formed in the pole connecting area, and the groove bottom of the first groove is an uneven rough surface. Under the condition that the current passing capacity of the battery connecting piece is ensured, the welding power requirement is lowered, welding burst points caused by too large welding power are avoided, and the oxidation blackening situation caused by the heat influence of welding of the battery connecting piece is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to lithium battery technical field especially relates to a battery connecting piece. BACKGROUND

[0002] At present, with the continuous improvement of environmental protection consciousness, more and more people begin to pay attention to environmental problems, especially the abnormal change of global climate, and it has been highly valued, which has become a social problem that human society needs to solve. In order to alleviate environmental problems, relevant technical personnel puts forward the scheme of using new energy vehicles instead of fuel vehicles, and achieves the effect of energy diversification, pollution reduction and energy utilization rate improvement.

[0003] The battery pack is the main power source of new energy vehicles, and has become one of the core components of electric vehicles. The battery pack includes a plurality of single batteries, and the single battery is generally connected with the pole and the pole ear through the battery connecting piece. In the prior art, the thickness of the battery connecting piece is between 0.4mm-1.5mm, one end of the battery connecting piece is welded to the pole, and the other end is welded to the pole ear. The battery connecting piece is welded to the surface of the pole bottom plate by laser welding.

[0004] At present, the design of the battery connecting piece is to make the thickness of each part consistent, and the thickness of the battery connecting piece in the laser welding area and other areas is the same. When the battery connecting piece is laser welded, in order to ensure the current passing capacity of the battery connecting piece, the battery connecting piece needs to meet the thickness requirement, but the increase of the thickness will lead to difficulty in laser welding penetration, and it is easy to produce virtual welding. By increasing the power welding, it will also lead to welding spatter, so that the welding area of the battery connecting piece is blackened.

[0005] Therefore, it is necessary to provide a battery connecting piece to solve the above problems. INVENTION CONTENTS

[0006] In order to overcome the above-mentioned shortcomings, the purpose of the utility model is to provide a battery connecting piece, which can reduce the welding power requirement under the condition of ensuring the current passing capacity of the battery connecting piece, avoid the welding spatter caused by excessive welding power, and reduce the oxidation blackening caused by the heat effect of the welded battery connecting piece.

[0007] In order to achieve the above purpose, the utility model adopts the technical scheme of: a battery connecting piece is used for connecting the pole and the pole ear arranged on the battery pack, comprising a connecting piece body; the connecting piece body is provided with a pole connecting area and a pole ear connecting area connected with the pole and the pole ear respectively; at least one first groove is formed in the pole connecting area, and the groove bottom of the first groove is a rough surface. The setting of the above-mentioned first groove can reduce the thickness of the welding position under the condition of unchanged thickness of the connecting piece body, so that the laser welding can easily penetrate the connecting piece body, and the requirement for welding power is greatly reduced.

[0008] Further, a second groove is formed in the bottom surface of the first groove in a direction towards the bottom of the lug body, or a welding bump is arranged on the surface of the first groove, or both a second groove and a welding bump are arranged on the surface of the first groove. By roughening the bottom surface of the first groove, the roughness of the bottom surface is increased, thereby reducing the reflection of light during laser welding, improving the light absorption rate during welding, and effectively avoiding the risk of poor welding or virtual welding during welding.

[0009] Further, the depth of the first groove is 20% to 60% of the thickness of the lug body. The depth of the first groove is reduced, that is, the welding thickness of the welding point is reduced, so that the laser can easily penetrate the lug body, thereby greatly reducing the requirement for welding power during welding, and further ensuring the welding efficiency of the lug body and the pole.

[0010] Further, the depth of the second groove is 0.05 to 0.2 mm.

[0011] Further, the distance D1 between two adjacent second grooves is 0.2 to 0.5 mm. The cross-sectional shape of the second groove can be rectangular, square, triangular, circular, elliptical, pentagonal, or other shapes. According to the selection and specific requirements of the actual situation, the cross-sectional shape of the second groove can be appropriately modified, which is not particularly limited here. There are 2 to 8 second grooves per square millimeter, which can meet the requirement of light absorption rate during welding.

[0012] Further, the second grooves or welding bumps are arranged in an array along the length direction of the first groove. The continuous structure of bumps, planes, and grooves formed on the bottom surface of the first groove can also increase the roughness of the bottom surface, thereby reducing the reflection of light during laser welding and improving the light absorption rate during laser welding.

[0013] Further, the bottom of the first groove is coated with a coating. The light absorption rate can be improved, and the preheating speed of the laser on the welded body can be accelerated.

[0014] Further, the coating is a UV ink coating, and the thickness of the coating is 0.2 to 2 microns. Specifically, the color of the UV ink can be black or gray. By spraying the above two colors, the pollution to the electrolyte can be reduced, so that the electrolyte can be recycled for subsequent use, thereby reducing the production loss of the enterprise. The setting of the coating can improve the light absorption rate and accelerate the preheating speed of the laser on the welded body, thereby improving the welding speed and efficiency of the laser welding.

[0015] Further, the pole connecting area and the tab connecting area are connected through the bending part. Through the setting of the bending part, when the connecting piece body is assembled with the pole and the tab in the battery pack, the pole connecting area and the tab connecting area will not overlap each other, thereby ensuring that the connecting piece body will not be short-circuited.

[0016] Further, the bending part is integrally formed with the pole connecting area and the tab connecting area, and the bending angle θ of the bending part is 110°-150°. The space waste in the battery pack is effectively avoided, and the overall space utilization rate of the battery pack is improved.

[0017] The beneficial effects of the utility model are as follows:

[0018] 1. In the utility model, a plurality of first grooves are formed in the pole connecting area of the connecting piece body from top to bottom, so that a local thickness difference is generated between the welding area connected with the pole and the connecting piece body. In the case that the overall thickness of the connecting piece body is unchanged, the welding position is reduced, the laser welding easily penetrates the connecting piece body, the requirement for welding power is greatly reduced in the case of ensuring the current passing capacity of the battery connecting piece, the welding power is prevented from being too large to cause welding explosion point, and the oxidation blackening caused by the welding battery connecting piece thermal influence is reduced.

[0019] 2. In the utility model, the groove bottom of the pole connecting area first groove is provided with a concave-convex surface, so that the light reflection in the laser welding process is reduced, the light absorption rate of laser welding is improved, and the efficiency of laser welding is improved.

[0020] 3. In the utility model, a coating is arranged on the groove bottom surface, which can improve the light absorption rate and also accelerate the preheating speed of the laser welding body, thereby improving the efficiency of laser welding. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the overall structure axial side view of an embodiment of the utility model;

[0022] Figure 2 It is the overall structure plan view of an embodiment of the utility model;

[0023] Figure 3 It is Figure 2 It is the enlarged structure schematic view of A in the figure;

[0024] Figure 4 It is the partial structure schematic view of an embodiment of the utility model;

[0025] In the figure: 1, connecting piece body; 2, pole connecting area; 3, tab connecting area; 4, bending part; 5, first groove; 6, groove bottom; 7, second groove; 8, welding bump. DETAILED DESCRIPTION

[0026] The advantages and features of the present application will be more clearly understood from the following detailed description of preferred embodiments, given by way of example only, with reference to the accompanying drawings, in which:

[0027] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed during use, and are merely for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third", and the like are only used for differentiation in description and cannot be understood as indicating or implying relative importance. The terms "horizontal", "vertical", "overhanging", and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0028] In the prior art, when the connecting piece body 1 is connected with the pole lug and the pole column on the battery pack, the pole lug is usually connected with the pole lug connection area 3 on the connecting piece body 1 through ultrasonic welding, which can prevent the pole lug from appearing welding spots or the connecting piece body 1 from being oxidized and blackened during welding. However, the connection between the pole column and the connecting piece is not suitable for ultrasonic welding, and is usually achieved by laser welding. However, during laser welding, welding spots or the connecting piece body 1 is often oxidized and blackened due to excessive welding power.

[0029] Therefore, in order to solve the above problems, the present application provides a battery connecting piece for connecting the pole column and the pole lug arranged on the battery pack. Figures 1 to 4 The battery connecting piece comprises a connecting piece body 1, and the connecting piece body 1 is provided with a pole column connection area 2 and a pole lug connection area 3 connected with the pole column and the pole lug, respectively. Specifically, the pole lug connection area 3 comprises a pole lug welding end and a pole lug connection end, and the pole column connection area 2 comprises a pole column welding end and a pole column connection end. The welding end of the pole lug connection area 3 and the pole column connection area 2 is the end far away from each other, and the connection end is the end close to each other. The pole lug connection end and the pole column connection end are arranged to connect the pole column connection area 2 and the connection area to form a complete battery connecting piece.

[0030] The pole connecting area 2 is provided with at least one first groove 5 from top to bottom, and the area in the first groove 5 is the welding area for connecting the connecting piece body 1 and the pole. The first groove 5 partially reduces the thickness of the connecting piece body 1, but does not reduce the overall thickness of the connecting piece body 1. Therefore, when the pole is welded with the pole connecting area 2, the current passing capacity of the connecting piece body 1 does not change, and the thickness of the connecting piece body 1 itself can meet the current passing demand during welding, so that the welding power does not need to be increased during welding, further reducing the requirement for welding power during welding, thereby avoiding the phenomenon of surface oxidation and blackening of the connecting piece body 1 due to the increase of welding power.

[0031] In addition, without increasing the thickness of the connecting piece body 1 and the welding power, the first groove 5 is arranged on the surface of the connecting piece body 1 in the application to reduce the thickness of the welding area, which can further ensure that there is no overwelding, virtual welding, and welding explosion point during laser welding, and effectively improve the stability of the welding and fixation of the connecting piece body 1 and the battery pack.

[0032] Referring to the accompanying drawings Figure 2 In some embodiments, the first groove 5 is arranged along the length direction of the pole connecting area 2 and is arranged in an array along the width direction of the pole connecting area 2. Specifically, the first groove 5 is arranged in four groups, and the four first grooves 5 are arranged in parallel with each other and do not intersect with each other. The arrangement of the multiple groups of first grooves 5 can make the welding of the pole and the pole connecting area 2 on the connecting piece body 1 more stable, and ensure that the connecting piece body 1 and the pole and the tab do not separate from each other even after the battery pack is used for a long time. The arrangement of the groove direction, length, and width of the multiple first grooves 5 is also matched with the laser welding path, so that the welding of the pole and the connecting piece body 1 is realized in the first groove 5.

[0033] It should be noted that the cross-sectional shape of the first groove 5 can be rectangular, oval, waist-shaped, or other shapes. The first groove 5 can be formed by directly stamping with a stamping head, and the overall production operation is simple and convenient for enterprise processing. For different shapes of the first groove 5, the staff can replace different shapes of the stamping head for stamping according to the needs.

[0034] Specifically, in some embodiments, the cross section of the first groove 5 is arranged in a waist-shaped structure. During production and processing, the staff replaces a matching waist-shaped stamping head one, places the connecting piece body 1 on the stamping workbench, starts the stamping workbench, and directly stamps downward with the waist-shaped stamping head one to stamp out the required first groove 5.

[0035] In some embodiments, the thickness of the connecting piece body 1 is 1.3-2 mm, and the depth of the first groove 5 accounts for 20-60% of the thickness of the connecting piece body 1. Within the above-mentioned depth range of the first groove 5, the distance between the surface of the groove bottom 6 and the bottom of the connecting piece body 1 makes it easier for laser welding to penetrate the welding area, thereby effectively avoiding the phenomenon of overwelding or false welding during welding and ensuring the welding efficiency of the pole and the connecting piece body 1.

[0036] In the above-mentioned embodiments, the thickness of the connecting piece body 1 can be 1.5 mm, 1.8 mm or 2 mm, which can meet the current passing capacity required by the connecting piece body 1 during laser welding and preliminarily ensure that there is no false welding phenomenon between the pole and the connecting piece body 1 during the welding process.

[0037] The depth of the first groove 5 is 0.4-0.8 mm, and the width of the first groove 5 is 1.0-3.0 mm. Specifically, the depth of the first groove 5 can be 0.5 mm, 0.6 mm or 0.8 mm, and the width of the first groove 5 can be 1.5 mm, 2 mm or 2.5 mm. The depth of the first groove 5 is reduced, that is, the welding thickness of the welding point is reduced, so that the laser can easily penetrate the connecting piece body 1, thereby greatly reducing the requirement for welding power during welding, and further ensuring the welding efficiency of the pole and the connecting piece body 1 on the premise that the thickness of the connecting piece body 1 meets the current passing capacity required by welding. It should be noted that the width of the first groove 5 also meets the movement path of the laser during laser welding, and can also ensure the welding area between the connecting piece body 1 and the pole and ensure the stability of welding.

[0038] Referring to FIG. 1, Figure 1 With 4 , the groove bottom 6 of the first groove 5 is a rough surface. By setting the groove bottom 6 as a rough surface, the roughness of the surface of the groove bottom 6 is improved, thereby reducing the reflection during laser welding and improving the light absorption rate during welding, effectively avoiding the risk of false welding or poor welding during welding.

[0039] Specifically, in some embodiments, the rough surface can be that a plurality of second grooves 7 are arranged on the surface of the groove bottom 6 of the first groove 5 in a direction towards the bottom of the connecting piece body 1, the plurality of second grooves 7 are arranged in the length direction of the groove bottom 6, the distance D1 between adjacent two second grooves 7 is 0.2-0.5 mm, and the depth of the second groove 7 is 0.05-0.2 mm.

[0040] The cross-sectional shape of the second groove 7 can be rectangular, square, triangular, circular, oval, pentagonal or other shapes. According to the actual situation and specific requirements, the cross-sectional shape of the second groove 7 can be appropriately modified, which is not particularly limited here. In the above embodiment, the shape of the second groove 7 can be selected as a square, and the side length of the square is 0.2-0.5 mm. Within each square millimeter, 2-8 second grooves 7 are provided, which can meet the requirements of light absorption rate during welding. Specifically, the side length of the second groove 7 can be 0.2 mm, 0.4 mm or 0.5 mm.

[0041] When the second groove 7 is opened, it is also formed by stamping. The bottom of the second stamping head is provided with a plurality of stamping blocks matched with the shape of the second groove 7. The connecting piece body 1 is placed on the stamping workbench. After the workbench is started, the second stamping head is pressed down to stamp a plurality of second grooves 7 on the groove bottom 6 of the first groove 5. The distance between the adjacent two stamping blocks at the bottom of the second stamping head is the same as the distance between the adjacent two second grooves 7.

[0042] In some embodiments, the rough surface can be a plurality of welding bumps 8 protruding from the surface of the groove bottom 6 of the first groove 5. The welding bumps 8 are also arranged in multiple along the length direction of the first groove 5 to form a concave-convex structure with the surface of the groove bottom 6, which can also reduce the reflection during laser welding and improve the light absorption rate during laser welding. Compared with the above-mentioned opening of a plurality of second grooves 7 at the bottom of the groove bottom 6, the forming of the welding bumps 8 in this embodiment is relatively complex, and the operation of opening the second groove 7 is more convenient, which can improve the processing efficiency of the connecting piece body 1. The distance D2 between the adjacent two welding bumps 8 is also 0.2-0.5 mm. The cross-sectional shape of the welding bump 8 can be rectangular, square, triangular, circular, oval, pentagonal or other shapes. According to the actual situation and specific requirements, the cross-sectional shape of the welding bump 8 can be appropriately modified, which is not particularly limited here.

[0043] In some embodiments, referring to FIG. 6, the rough surface can be formed by opening a plurality of second grooves 7 in the direction towards the bottom of the connecting piece body 1 and a plurality of welding bumps 8 protruding from the surface. The second grooves 7 and the welding bumps 8 are arranged alternately and also arranged in an array along the length direction of the first groove 5 to form a continuous structure of bumps, planes and grooves on the surface of the groove bottom 6, which can also increase the roughness of the surface of the groove bottom 6, reduce the reflection during laser welding and improve the light absorption rate during laser welding. Figure 4

[0044] ​The groove bottom 6 of the first groove 5 is coated with a coating. The coating can improve the light absorption rate, accelerate the preheating speed of the laser butt joint body, and thus improve the welding speed and efficiency of the laser welding. In some embodiments, the coating is a UV ink coating, and the thickness of the coating is 0.2-2 μm. Specifically, the color of the UV ink can be black or gray, and the above two colors can reduce the pollution of the electrolyte, so that the electrolyte can be recycled for subsequent use, thereby reducing the production loss of the enterprise. The thickness of the coating can be 0.5 μm, 1 μm, 1.5 μm or 2 μm. The thickness range can ensure that the light absorption rate of the coating reaches the highest. In addition, the coating can be realized by spraying.

[0045] In some embodiments, the opposite faces of the tab connecting end on the tab connecting area 3 and the pole connecting end on the pole connecting area 2 are directly fixed to each other, and the tab connecting area 3 and the pole connecting area 2 can be integrally formed into a connecting sheet body 1 for battery connection when the connecting sheet body 1 is produced. The connection between the pole connecting end and the tab connecting end on the connecting sheet body 1 is a smooth surface.

[0046] The connection and fixation of the above-mentioned tab connecting area 3 and pole connecting area 2 do not affect the welding and fixation of the tab and the pole, respectively, but after being installed in the battery pack, it will occupy a large space in the battery pack, thereby cannot guarantee the space utilization rate inside the battery. Therefore, in order to increase the use space inside the battery after the connecting sheet body 1 and the pole and the tab are installed, the pole connecting area 2 and the tab connecting area 3 are connected by the bending part 4 in the utility model.

[0047] Referring to the accompanying drawings Figure 1 The bending part 4 is arranged in a Z shape, and the two ends in the length direction thereof are respectively a connecting end one and a connecting end two. The connecting end one is connected with the pole connecting end on the pole connecting area 2, and the connecting end two is connected with the tab connecting end on the tab connecting area 3. After being connected into a complete connecting sheet body 1, the straight line in the length direction of the pole connecting area 2 is above the straight line in the length direction of the tab connecting area 3, and the two straight lines are parallel to each other in the same plane.

[0048] The bending angle θ of the bending part 4 is 110°-150°. Specifically, the bending angle θ refers to the included angle between the inclined surface of the Z-shaped bending part 4 and the horizontal surface connecting the tab connecting end. In some embodiments, the bending angle θ can be 120°, 135° or 145°. Of course, appropriate adjustments can be made according to the actual situation and specific needs, which are not particularly limited here.

[0049] Two corners on the Z-shaped bending part 4 are provided with rounded corners, so that the overall structure of the connecting sheet body 1 is more beautiful, and the worker will not be scratched when taking. In addition, through the arrangement of the bending part 4, when the connecting sheet body 1 is assembled with the pole and the tab in the battery pack, the pole connecting area 2 and the tab connecting area 3 will not overlap each other, thereby ensuring that the connecting sheet body 1 will not be short-circuited.

[0050] It should be noted that the bending part 4 is not limited to Z-shaped, as long as it can form a stepped shape and a height difference between the pole connecting area 2 and the tab connecting area 3 after the connection. After the connecting sheet body 1 is installed in the battery pack, the space between the upper surface of the tab connecting area 3 and the top of the inner wall of the battery pack can be used to install other battery pack accessories with small volume, thereby effectively avoiding the waste of space in the battery pack and improving the overall space utilization of the battery pack.

[0051] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made in accordance with the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A battery connector for connecting a terminal post and a tab disposed on a battery pack, characterized in that: The connecting sheet body is provided with a pole connecting area and a tab connecting area connected with a pole and a tab respectively, at least one first groove is arranged in the pole connecting area, and the groove bottom of the first groove is uneven.

2. The battery tab of claim 1, wherein: The surface of the groove bottom of the first groove is provided with a plurality of second grooves or a plurality of welding convex points, or is provided with a plurality of second grooves and a plurality of welding convex points.

3. The battery tab of claim 1, wherein: The depth of the first groove accounts for 20-60% of the thickness of the connecting sheet body.

4. The battery tab of claim 2, wherein: The depth of the second groove is 0.05-0.2 mm.

5. A battery tab as defined in claim 4, wherein: The interval D1 between two adjacent second grooves is 0.2-0.5 mm.

6. The battery tab of claim 2, wherein: The plurality of second grooves or welding convex points are arranged along the length direction of the first groove.

7. The battery tab of claim 1, wherein: The groove bottom of the first groove is coated with a coating.

8. A battery tab according to claim 7, characterized in that: The coating is a UV ink coating, and the thickness of the coating is 0.2-2 μm.

9. The battery tab of claim 1, wherein: The pole connecting area and the tab connecting area are connected through a bending part.

10. A battery tab as defined in claim 9, wherein: The bending part is integrally formed with the pole connecting area and the tab connecting area, and the bending angle θ of the bending part is 110-150°.

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