WINDING TYPE LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a winding type lithium ion secondary battery having high reliability in the long-term use.

SOLUTION: The winding type lithium secondary battery has a wound group 11 formed by winding a positive electrode and a negative electrode each having a lead piece at the end part in the length direction of metal foil through a separator, a positive lead piece 15 is connected to the outer peripheral surface of a positive current collecting ring 14, and when the outer diameter of the positive current collecting ring 14 is A (mm) and the outer diameter of the wound group 11 is B (mm), A and B are set in a range of 0.75COPYRIGHT: (C)2009,JPO&INPIT