Welding method for tabs and poles of high-power lithium-ion batteries

Abstract

The invention relates to a welding method for high-power lithium-ion battery lugs and poles. The steps include: 1. Assembling an electron beam welding device; 2. Putting the device into the vacuum chamber of an electron beam welding machine; 3. Starting the electron beam Welding machine, the electron gun emits electron beams that penetrate the multi-layer copper negative pole ear and penetrate into the negative pole column to form a molten pool, so that the weld seam at the interface between the multi-layer copper negative pole ear and the negative pole pole is melted into one, and the multi-layer copper negative pole ear and the negative pole pole are controlled. The width of the cross-section at the center of the molten pool on the interface of the negative pole is more than 0.5 mm. The invention adopts the electron beam welding method to melt the interface between the multi-layer copper negative lug and the copper negative pole to form a molten pool, and the multi-layer copper negative lug and the negative pole are welded into an inseparable one, which ensures the multi-layer copper negative lug and the negative pole The reliability of the column connection ensures that the battery can still work reliably even after several mechanical vibrations or high and low temperature cycles.

Description

technical field [0001] The invention belongs to the technical field of high-power lithium-ion batteries, and in particular relates to a welding method for tabs and poles of high-power lithium-ion batteries. Background technique [0002] Lithium-ion batteries have been widely used due to their high specific energy, long charge and discharge life, and wide operating temperature range. With the advancement of electronic technology, the high power requirements of lithium-ion batteries are getting higher and higher. [0003] Due to the high thermal conductivity of copper, copper has become the material of choice for high-power lithium-ion battery negative poles and multi-layer copper negative tabs. The multi-layer copper negative tabs and copper negative poles of high-power batteries should not be connected by resistance welding; due to the high reflectivity of copper, laser welding should not be used. This increases the difficulty of welding. At present, riveting has become th...

AI Technical Summary

Problems solved by technology

With the development of aerospace technology, the requirements for high power and high reliability of high-power lithium-ion batteries have also increased. Due to the particularity of complex mechanical vibration and large temperature differences in the aerospace environment, high-power lithium-ion batteries During the use of the riveted multi-layer copper negative tabs and copper negative poles, the riveted parts of the multi-layer copper negative tabs and copper negative poles will loosen because the battery has to experience several times of mechanical vibration and high and low temperature cycles with large temperature differences. , resulting in a virtual connection of the battery electrodes, affecting the reliability of the battery and shortening the service life of the battery

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