Patent ID: 7432018
Filing Date: 2008-10-07
Classification: H01M,Y02E,Y02P

Abstract:
1. A cylindrical alkaline storage battery, comprising: an electrically-conductive cylindrical outer can; and an electrode group accommodated in the outer can together with an alkaline electrolyte, said electrode group being formed by rolling up together a positive electrode, a negative electrode placed outside the positive electrode and including a strip-shaped negative-electrode core body and an active material layer supported by the negative-electrode core body, and a separator inserted between the postive electrode and the negative electrode, an outermost circumferential part of the electrode group being formed of the negative electrode and in contact with a circumferential wall of the outer can, said negative electrode extending beyond an outer end of the positive electrode in a circumferential direction of the electrode group, wherein said negative electrode comprises: a main part forming an inside part of the electrode group, a thin part forming the outermost circumferential part of the electrode group, the thin part being smaller in thickness of the active material layer and smaller in amount of the active material contained in unit volume of the active material layer than the main part, and a boundary part formed between the main part and the thin part in which the thickness of the active material layer changes in a lengthwise direction of the negative-electrode core body; and the outer end of the positive electrode and the boundary part of the negative electrode are positioned at different positions in the circumferential direction of the electrode group, wherein the negative-electrode core body is made of punching metal, wherein the active material layer of the negative electrode is supported on outer and inner sides of the negative-electrode core body, and wherein in the thin part of the negative electrode, the active material layer supported on the inner side of the negative-electrode core body is thicker than the active material layer supported on the outer side of the negative-electrode core body.