Secondary batteries and their manufacturing methods

Abstract

This invention provides a secondary battery with excellent manufacturability and that is less prone to short circuits between the positive-side current collector and the negative-side current collector. A secondary battery 1 is an all-solid-state battery comprising an energy storage element 2 having a positive electrode layer 6, a negative electrode layer 7, and a solid electrolyte layer 5, a positive-side current collector layer 3, and a negative-side current collector layer 4; and, in top view, the outer peripheries 6a and 7a of the positive electrode layer 6 and the negative electrode layer 7 are disposed closer to the outer periphery 5a of the solid electrolyte layer 5; in top view, the positive-side current collector layer 3 has a positive-side current collector body portion 8 disposed closer to the outer periphery 5a of the solid electrolyte layer 5, and a positive-side current collector protrusion 9 protruding from the end face 8b of the positive-side current collector body portion 8, the positive-side current collector protrusion 9 having a connection with the solid electrolyte layer 5. The positive electrode side current collector protruding end face 9a is arranged in a manner aligned with the end face 5b of the solid electrolyte layer 5; when viewed from above, the negative electrode side current collector layer 4 has a negative electrode side current collector body portion 10 disposed on the inner side of the outer periphery 5a of the solid electrolyte layer 5, and a negative electrode side current collector protrusion 11 protruding from the end face 10b of the negative electrode side current collector body portion 10. The negative electrode side current collector protrusion 11 has a negative electrode side current collector protruding end face 11a arranged in a manner aligned with the end face 5b of the solid electrolyte layer 5; when viewed from above, the positive electrode side current collector protruding end face 9a and the negative electrode side current collector protruding end face 11a do not overlap.