LITHIUM ION SECONDARY BATTERY

PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery having an enhanced battery capacity in which the risk of the degradation of safety is eliminated as likely according to the conventional configuration, such that a positive lead is welded to the reaction surface of a positive electrode plate and the mix of positive electrode active material is peeled in the welded part for leading to a decrease in the battery capacity, wherein a losses in the safety are produced in association with an internal short-circuiting, resulting from exposure of the positive electrode lead or the penetration of an insulation tape by burrs, etc., at the dge of the positive electrode lead. SOLUTION: The shape of a positive electrode plate 1 is made different from that of a conventional item, and an electricity-collecting part 9 is provided on the base material for applying a mix of positive electrode active materials, and thereby the conventional process to weld a positive electrode lead to the reaction surface of the positive electrode plate is eliminated, and the use of an insulation tape covering the welded part for preventing internal short- circuiting can be discontinued. This enables enhancement of safety and increase in the battery capacity, and a lithium ion secondary battery having a high capacity and high safety can be established.