US Patent 11189874 Secondary battery and method of manufacturing the same

A method of manufacturing a secondary battery includes the following steps. An insertion portion of a negative-electrode terminal is inserted into a terminal connection hole that is formed in a first negative-electrode current collector and crimped on a tapered portion to form a crimped portion. A gap is formed between the crimped portion and the tapered portion. Energy rays are radiated toward at least one of the crimped portion and the tapered portion to melt the at least one of the crimped portion and the tapered portion such that a melted metal flows into the gap. The melted metal is solidified to form a solidified portion, and the negative-electrode terminal and the first negative-electrode current collector are joined to each other. The solidified portion has a recessed portion.