Battery and method for manufacturing same

A method of manufacturing a battery, the battery including:

• an electrode body which has a positive electrode and a negative electrode;
• an outer package which has an opening and which houses the electrode body;
• a sealing plate which seals the opening of the outer package and which has a through-hole and a recessed portion provided around the through-hole on a surface on a side opposing the electrode body;
• and
• a sealing member which seals the through-hole of the sealing plate,
• the sealing member having an inserted portion having been inserted to the through-hole and an enlarged diameter portion which extends from the inserted portion to inside of the outer package and which is formed with a larger diameter than the inserted portion, and
• at least a part of the enlarged diameter portion being arranged inside the recessed portion of the sealing plate,
• the method of manufacturing a battery comprising:
• forming the enlarged diameter portion by inserting the sealing member into the through-hole from the outside of the outer package and causing a tip of the sealing member to deform;
• and
• after forming the enlarged diameter portion, confirming whether or not the enlarged diameter portion has a predetermined shape by emitting X-rays.