SECONDARY BATTERY, LAYER-BUILT SECONDARY BATTERY AND BATTERY PACK

摘要

A secondary battery (4) includes collector electrodes (21, 23), a contact area of the collector electrode in contact with a cathode (28) or a anode (26), a terminal portion formed in the collector electrode (21, 23) and not in contact with the cathode or anode, and a connecting portion to which a conductive member is connected. As compared with cross-sectional area of the terminal portion forming a first current path between the connecting portion and a first portion of the contact area closest to the connecting portion in the contact area, cross-sectional area of a terminal portion forming a second current path between the connecting portion and a second portion positioned in a region of the periphery of the contact area and extending along the terminal portion, of which length to the connection portion is longer than path length of said current path, is made larger.