Secondary battery and fabrication method thereof

A secondary battery comprising:

• a jelly roll that includes a positive electrode and a negative electrode wound via a separator;
• a case housing the jelly roll;
• a lid that seals the case;
• and
• electrically conductive input/output members via which charge/discharge currents are input and output between the jelly roll and an external load, wherein:
• the electrically conductive input/output members include, at least;
• a positive electrode current collector plate with one end thereof connected to the positive electrode;
• a negative electrode current collector plate with one end thereof connected to the negative electrode;
• a positive electrode connector terminal with one end thereof connected to the positive electrode current collector plate;
• a negative electrode connector terminal with one end thereof connected to the negative electrode current collector plate;
• and
• a positive electrode external terminal disposed on an outer side of the lid, which is swage-fused with the positive electrode connector terminal with another end of the positive electrode connector terminal passing through the positive electrode external terminal;
• a negative electrode external terminal disposed on the outer side of the lid, which is swage-fused with the negative electrode connector terminal with another end of the negative electrode connector terminal passing through the negative electrode external terminal;
• and
• an oxide layer is formed at a surfaces of each swage-fused area where the positive or negative electrode connector terminal is swage-fused to the positive or negative electrode external terminal, wherein the other end of the swage-fused positive electrode connector terminal and the other end of the swage-fused negative electrode connector terminal each include a staged portion projecting out through a surface of the positive electrode external terminal or the negative electrode external terminal;
• and the positive electrode connector terminal is fused with the positive electrode external terminal at the staged portion and the negative electrode connector terminal is fused with the negative electrode external terminal at the staged portion, with the oxide layer formed at the surface of each swage-fused area.