Novel welding method for series connection of soft package lithium battery modules

Abstract

The invention discloses a novel welding method for series connection of soft package lithium battery modules. The method comprises the following steps: horizontally placing a PCB, enabling aluminum tabs and copper tabs on the soft package lithium battery modules to be welded in series to penetrate through adjacent clamping grooves in the PCB from bottom to top, and for each group of aluminum tabs and copper tabs which penetrate through the PCB and are to be welded and connected, folding and attaching the aluminum tabs down towards the upper end face of the PCB between the adjacent clamping grooves through which the aluminum tabs and the copper tabs penetrate,; and coating the upper end face of the folded aluminum tabs with soldering paste, folding and attaching the copper tab towards the upper end face of the corresponding aluminum tab to be welded and connected, and vertically pressing a pair of resistance welding electrodes on the folded copper tabs from top to bottom for resistance welding. The method is simple and reliable in process, low in power consumption, low in environment requirement, high in welding efficiency, high in welding performance and low in welding equipment cost and use and maintenance cost.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a novel welding method for connecting soft-pack lithium battery modules in series. Background technique [0002] With the development of battery technology, especially lithium-ion batteries, the battery pack composed of single lithium batteries can be used as a power supply, both as a power battery and as an energy storage battery, and has been widely used in electric vehicles, storage Power stations and other fields. The positive electrode of the single lithium battery is an aluminum sheet, and the negative electrode is a copper sheet. Single lithium batteries need to be connected in series to form a battery pack. The existing lithium battery pack is composed of two or more single lithium batteries stacked and connected in series. There are two main ways to connect the aluminum electrodes and copper electrodes of adjacent single lithium batteries: one is laser weldin...

AI Technical Summary

Problems solved by technology

The pain point is that the tinning time is long, and the high temperature of molten tin higher than 350°C will be conducted into the battery cell, causing irreversible damage to the battery cell and damaging the performance of the battery group, and the efficiency is low and the quality consistency is poor

[0003] In order to solve the above-mentioned problems, Chinese Patent Publication No. CN 209461558U discloses a lithium battery pack with electrodes directly welded, in which the aluminum electrodes and copper electrodes vertically placed on adjacent single lithium batteries are directly welded together. The connection between the copper and aluminum electrodes of the bulk lithium battery is firm, it can be overloaded with a large current, and at the same time avoids the electrical corrosion phenomenon caused by the connection between the copper electrode of the lithium battery and the aluminum electrode of the lithium battery, and has a small connection internal resistance, but when used, there are the following Disadvantages: First, when using it, it is necessary to use a sampling line to connect the electrodes, which is relatively cumbersome; second, the aluminum electrodes and copper electrodes are placed vertically, and the gap between the adjacent aluminum electrodes and copper electrode groups to be welded is small. Inserting into the welding position in the gap between adjacent aluminum electrodes and copper electrode groups to be welded, this process is time-consuming and labor-intensive, and the production efficiency is low

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