RECTANGULAR SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a rectangular secondary battery including an external terminal and a terminal block connected mechanically and electrically by a caulking portion and a welding portion by a high energy beam, in which reliability is enhanced by enhancing the bonding strength between the external terminal and the terminal block while suppressing variation in the internal resistance.SOLUTION: Upper end side of a caulking portion 17e of a positive electrode external terminal 17 is caulked to a positive electrode terminal block 41 and connected electrically therewith, and the caulking portion 17e is welded to the positive electrode terminal block 41 by irradiation with a high energy beam. The negative electrode side has the same configuration as the positive electrode side. Contact area of the positive electrode terminal block 41 and the caulking portion 17e of the positive electrode external terminal 17 is smaller than the corresponding contact area on the negative electrode side, and the volume at the caulking portion of the positive electrode external terminal is larger than the volume of the corresponding caulking portion on the negative electrode side.