US Patent 11296388 Secondary battery

A secondary battery includes an outer can, a sealing body sealing an opening of the outer can, an electrode group housed together with an electrolyte inside the outer can, and a positive electrode current collector arranged between the electrode group and the sealing body. The positive electrode current collector has a current collector center through hole provided at a position facing an electrode group through hole of the electrode group. The sealing body includes a lid plate having an exhaust hole at the center, a valve body arranged at a position closing the exhaust hole from the outside of the lid plate, and a positive electrode terminal electrically connected to the lid plate and housing inside with the valve body pressed toward the lid plate. An inner diameter dimension DC of the current collector center through hole of the positive electrode current collector is equal to or less than an inner diameter dimension DL of the exhaust hole.