US Patent 12091725 Method of manufacturing cylindrical battery case having reduced surface roughness

A method of manufacturing a cylindrical battery case includes performing an ironing process, which is one of the processes of manufacturing the battery case, a plurality of times in order to decrease the surface roughness of the battery case, thereby improving the corrosion characteristics of the battery case. The surface roughness of the cylindrical battery case is decreased by performing a thickness reducing process when a process for forming the outer circumferential surface of a body of the cylindrical battery case is performed at the time of manufacturing the cylindrical battery case. In addition, corrosion characteristics are improved for respective values of the surface roughness.