Gs Yuasa International Ltd.

Kie Tanaka

Hidefumi Hasegawa

An energy storage device includes: a negative electrode having a negative composite layer on a negative electrode collector foil and a negative composite layer non-forming part along a side of a negative electrode collector foil; a positive electrode including a positive composite layer on a positive electrode collector foil and a positive composite layer non-forming part along a side of the positive electrode collector foil; and a separator including an insulating layer on its surface opposing the positive electrode. An end Son a side of the negative electrode current collector of the separator is projected more than an end Pon the side of the negative electrode current collector of the positive composite layer, an end Son a side of the positive electrode current collector of the separator is projected more than an end Pon the side of the positive electrode current collector of the positive composite layer, and a distance Wfrom the end Pto the end Sis smaller than a distance Wfrom the end Pto the end S

Energy storage device

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.

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Kyoto, Japan

Kie Tanaka