A lithium ion battery with square aluminum shell and an assembling method

Abstract

The invention relates to a lithium ion battery with a square aluminum shell, the battery comprises a shell and a cover plate, wherein the shell is provided with a rolling core, an electric conductor and a current collector; two ends of the rolling core are provided with lug flattening positions, and the electric conductor is welded to the lug flattening positions; the current collector is providedwith a clamping part and a welding part; the clamping part is clamped with the electric conductor; and the welding part is welded to the cover plate. According to the lithium battery, first the electric conductor is welded to the rolling core lug flattening positions, and then the electric conductor and the current collector are coated and assembled, so that the welding positions can be protected, the conductive cross-sectional area of the current collector is relatively large, the conductive flow rate is increased, the high-multiplying power charge and discharge can be realized, and the heatproduction amount of the current collector is relatively reduced.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a square aluminum shell lithium ion battery and an assembly method. Background technique [0002] At present, there are mainly two schemes for prismatic batteries, one is the all-tab design scheme, and the other is the multi-tab design scheme. The assembly scheme of all tabs is: winding - shaping - welding of positive and negative poles of the winding core and the current collector (the current collector and the cover plate are integrated) - wrapping the insulating film - entering the shell; multi-tab assembly scheme: positive and negative poles Ear die-cutting-winding-setting-welding of positive and negative poles of the core and cover plate-wrapping insulating film-into the shell. The traditional full tab solution does not need to die-cut the uncoated foil due to the simple process, but the positive and negative blanks are welded to the current collector through ...

AI Technical Summary

Problems solved by technology

The traditional full tab solution does not need to die-cut the uncoated foil due to the simple process, but the positive and negative blanks are welded to the current collector through ultrasonic welding. Due to the large welding area and the gap between layers during welding The dislocation of the positive and negative electrodes leads to a high proportion of white space in the coating of the positive and negative electrodes, and the effective volume of the winding core is small. The energy density of the full tab solution of the same size is lower than that of the multi-tab solution; Die-cutting of the uncoated part of the die-cut pole piece has many faults during the winding process, and the product production efficiency is low. When the design blank is relatively long, the process loss is much caused, and it has a certain impact on the improvement of compaction.

Whether it is full tab assembly or multiple tab assembly, the current collector is welded to the winding core by welding. Since there are pits or protrusions on the surface of the current collector after welding, it is easy to cause damage to the insulating film behind and cause battery damage. short circuit

Once the welding position falls off, there is a certain danger without corresponding protective measures

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