Patent ID: 10505229

Abstract:
The energy storage device of the present invention includes: a negative electrode including a negative composite layer and a composite layer non-forming portion on both surfaces of a negative electrode current collecting foil respectively; a positive electrode including a positive composite layer on both surfaces of a positive electrode current collecting foil respectively; and a separator including an insulation layer which faces the positive electrode and is interposed between the negative electrode and the positive electrode. The negative electrode, the separator and the positive electrode are stacked in a first direction. The negative composite layer and the composite layer non-forming portion are disposed adjacently to each other in a second direction orthogonal to the first direction on the respective surfaces of the negative electrode. The separator is configured to project in the second direction from the positive composite layer at one end of the separator in the second direction. The separator contains a first bent portion including a recessed surface on a surface thereof which faces the negative electrode at a portion projecting in the second direction from the negative composite layer. The first bent portions of the separators disposed adjacently to each other in the first direction are brought into contact with each other.