Patent ID: 8247115

Claim:
A wound-type electric storage device comprising: a stacked electrode sheet group that is formed by stacking a plurality of electrode sheets and accommodated in a casing as wound; one of a positive electrode and a negative electrode, including a first electrode sheet that is provided at one of outermost layers of the stacked electrode sheet group, and includes a first electrode current collector and a first electrode mixture layer applied onto one surface of the first electrode current collector, and a second electrode sheet that is provided at another one of the outermost layers of the stacked electrode sheet group, and includes a second electrode current collector and a second electrode mixture layer applied on one surface of the second electrode current collector; and the other one of the positive electrode and the negative electrode, including a third electrode sheet that is provided between the first electrode sheet and the second electrode sheet, and includes a third electrode current collector and a third electrode mixture layer applied on both surfaces of the third electrode current collector, wherein an ion source sheet, which supplies ions to at least any one of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer, is overlapped on the stacked electrode sheet group, and the stacked electrode sheet group is wound together with the ion source sheet, in order that one surface of the ion source sheet is faced to the first electrode sheet, while the other surface of the ion source sheet is faced to the second electrode sheet, wherein the lengths of the first electrode mixture layer, the second electrode mixture layer, the third electrode mixture layer and the ion source sheet are adjusted such that, when the stacked electrode sheet group and the ion source sheet are wound, the first electrode mixture layer and the second electrode mixture layer are positioned to always face the third electrode mixture layer and that the ion source sheet is positioned to always overlap the first electrode mixture layer, the second electrode mixture layer and the third electrode mixture layer, and each of the first electrode sheet and the second electrode sheet is the positive electrode.