METHOD FOR WELDING PLURAL ELECTRODE TAB AND ELECTRODE LEAD OF SECONDARY BATTERY AND SECONDARY BATTERY USING THE SAME METHOD FOR INSPECTING POOR WELDING OF SECONDARY BATTERY

摘要

The present invention relates to a method of welding a plurality of electrode tabs and electrode leads of a secondary battery having an electrode assembly, the method comprising the steps of: (a) forming a plurality of electrode tabs extending from a plurality of electrode plates constituting the electrode assembly, Overlapping each other; (b) positioning the electrode leads on the upper or lower portions of the plurality of electrode tabs so as to overlap with a part of the plurality of electrode tabs overlapping with each other; (c) forming a welding surface by welding a plurality of electrode tabs and the electrode lead overlapping portion using a welding apparatus, wherein in the step (c), the length of the welding surface is 0.4 mm or more and 0.7 mm or less. Thus, it is possible to prevent the welding failure due to weak welding of the plurality of electrode tabs and the electrode leads and the disconnection of the electrode tab due to the strong welding.