Secondary battery

A secondary battery comprising:

• exterior bodies that look a quadrilateral as a whole in a plan view, the exterior bodies each being a sheet member of an exterior material;
• an electrode body that is housed in the exterior bodies, the electrode body comprising:
• a cathode current collector layer;
• a cathode active material layer;
• a separator layer;
• an anode active material layer;
• and
• an anode current collector layer;
• cutout parts at respective two sides among sides of the quadrilateral, the two sides being opposite to each other, the two cutout parts being provided at respective corners of the quadrilateral, walls of the exterior bodies extending along sides of the quadrilateral and terminating at the two cutout parts before the respective corners of the quadrilateral, the corners being opposite to each other, the two cutout parts being provided at all the exterior bodies and the electrode body, cross sections of the two cutout parts being perpendicular to the plane direction;
• a cathode terminal disposed in one of the cutout parts;
• and
• an anode terminal disposed in another one of the cutout parts, wherein
• the cathode and anode terminals extend in two directions orthogonal to one another and parallel to the electrode body, the cathode and anode terminals extending beyond an outer perimeter of the electrode body in the two directions, and
• part of the cathode terminal and part of the anode terminal are enclosed within the exterior bodies and extend in a direction parallel to the electrode body.