CN205335338U - Power lithium cell electricity core and header connection structure - Google Patents

Abstract

The utility model provides a power lithium cell electricity core and header connection structure. Belong to lithium ion power batteries technical field. It mainly is a problem of solving current flexible coupling reliability. Its leading features is: electric core and top cap including the dispersion, the electric core that disperses on average divides into the electric core of first group, the electric core of second group, and the utmost point ear outside difference spot welding of first group electricity core, the electric core of second group forms first group prewelding plane, second group prewelding plane, first group prewelding plane, second group prewelding plane and the direct laser welding of the utmost point styletable face of top cap. The utility model has the characteristics of simple process welds the good reliability, is favorable to the production of follow -up equipment and notes liquid process, mainly used has multipolar ear structure and rolls up being connected of utmost point intercolumniation on core and the top cap.

Description

A connection structure between a power lithium battery cell and a top cover

technical field

The utility model belongs to the technical field of lithium-ion power batteries, and in particular relates to a lithium-ion power battery component, in particular to a connection structure between an inner winding core of the lithium-ion power battery and a shell cover plate pole.

Background technique

Lithium-ion power batteries are generally composed of multiple winding cores. The circuit channels of each winding core need to be effectively connected to the poles on the cover plate of the battery case. During use, the circuit connection is required to be reliable, durable, able to withstand mechanical shocks, and able to Withstand high current charge and discharge. To this end, before connecting the poles between the tabs 2 of the battery core 1 and the poles of the top cover 6, a deformable and conductive soft connection sheet 5 is used, and multiple pre-welding & ultrasonic welding are used. 3. Laser welding 4 and detection to ensure connection reliability, as shown in Figure 1 and Figure 2. In the previous design, the soft connecting piece 5 is firstly welded on the pole of the top cover 6 by laser welding, and the tab 2 of the cell 1 is pre-welded with a fine-toothed welding head, and then the pre-welded tab 2 When performing high-power ultrasonic welding with the flexible connecting piece 5, often the pre-welded position of the tab 2 is misaligned with the welding head during high-power ultrasonic welding, resulting in poor welding results. At the same time, the high-power ultrasonic welding technology is immature, and the life of the welding head is only 5 ~80,000 times. In addition, the ultrasonic welding head needs to avoid the interference of the top cover 5 when welding. The position of the folded tab (Z-shaped bend) cannot be at the welding place, so the soft connection piece will occupy the electrolyte space during liquid injection for a long time and cause the battery A second injection is required during production. For this reason, it is necessary to adopt a new design to replace the existing soft connection method, reduce the difficulty of the process and improve the quality of the battery on the basis of ensuring the performance of the battery.

Contents of the invention

The utility model is used to overcome the defects of the prior art and provide a connection structure of a power lithium battery cell and a top cover with reliable connection and easy production.

The technical solution of the utility model is: a power lithium battery cell and top cover connection structure, including dispersed cells and top cover, characterized in that: the dispersed cells are divided into the first group of cells and the second group of cells on average. Two sets of electric cores, the first set of electric cores and the outer sides of the second set of electric cores are spot-welded respectively to form the first set of pre-welding planes and the second set of pre-welding planes; the first set of pre-welding planes and the second set of pre-welding planes The flat surface is directly laser welded to the pole end face of the top cover.

The area of the first group of pre-welding planes, the second group of pre-welding planes and the end face of the pole described in the technical solution of the utility model is 2:1.

Because the utility model divides the scattered cells of the power lithium battery into the first group of cells and the second group of cells, the outer sides of the first group of cells and the second group of cells are respectively spot-welded to form the first group of pre-welding Plane, the second group of pre-welding planes, the plane pre-welding is to facilitate the laser welding of the subsequent battery cell and the pole on the top cover, the first group of pre-welding planes, the second group of pre-welding planes and the pole end of the top cover are directly Welding constitutes a new cell-to-pole connection structure that cancels the existing soft connection piece, and the use of laser welding instead of ultrasonic welding has the characteristics of reliable welding ability. The process is simple, the welding reliability is strong, and it is beneficial to the production of subsequent assembly and liquid injection processes. The utility model is mainly used for connecting lithium-ion power cells and poles.

Description of drawings

FIG. 1 is a schematic diagram of the connection structure between the existing battery cell and the top cover pole.

Fig. 2 is a schematic diagram of the structure of the folded tabs of the existing battery cell and the top cover pole.

Fig. 3 is a schematic diagram of the connection structure between the electric core and the top cover pole of the present invention.

Fig. 4 is a schematic diagram of the structure of the folded tab of the present invention.

In the figure: 1. Battery core, 2. Tabs, 3. Pre-welding & ultrasonic welding, 4. Laser welding, 5. Soft connection sheet, 6. Top cover, 7. The first group of batteries, 8. Tabs, 9. Laser welding & pre-welding position, 10. Tabs, 11. The second set of batteries.

detailed description

As shown in Figure 3 and Figure 4. The connection structure between the power lithium battery cell and the top cover of the utility model includes scattered cells and a top cover 6, and the dispersed cells are evenly divided into the first group of cells 7, the second group of cells 11, the first group of cells 7, The outer sides of the tabs 8 and 10 of the second group of cells 11 are respectively spot welded and flat compacted to form high-quality first group of pre-welded planes and second group of pre-welded planes. The method is ultrasonic pressure welding or high-pressure heating. Welding can directly carry out laser welding with the upper pole of the top cover 6. The area of the first group of pre-welding planes, the second group of pre-welding planes and the pole end face is 2:1. The first group of pre-welding planes and the second group of pre-welding planes are directly laser welded to the pole end face of the top cover 6 .

The utility model cancels the soft connecting piece 5, cancels the laser welding process and equipment between the direct cell and the pole on the top cover of the soft connection, reduces the zigzag bending by folding the tabs, and uses laser welding instead of ultrasonic welding to have reliable welding ability specialty. The simplified structure of the utility model makes the welding performance of the battery stable during the production process, and the service life of the laser welding head up to 20 million times is much higher than that of the ultrasonic welding, thereby improving the service life of the battery.

Claims (2)

1. A connection structure between a power lithium battery cell and a top cover, comprising dispersed cells and a top cover, characterized in that: the dispersed cells are evenly divided into a first group of cells and a second group of cells, the first The first group of pre-welding planes and the second group of pre-welding planes are spot-welded on the outer sides of the tabs of the first group of batteries and the second group of batteries; The end faces are directly laser welded. 2. A power lithium battery cell and top cover connection structure according to claim 1, characterized in that: the area of the first group of pre-welding planes, the second group of pre-welding planes and the pole end surface is 2 :1.