LITHIUM ION SECONDARY BATTERY

PROBLEM TO BE SOLVED: To effectively restrain a cathode and an anode from short-circuiting while restraining deterioration of charge and discharge characteristics caused by expansion of a spiral electrode in a cylindrical lithium ion secondary battery using an anode active material alloyed with lithium. SOLUTION: The lithium ion secondary battery 1 has the spiral electrode 20, and a cylindrical battery container 10. The spiral electrode 20 has the anode 21, the cathode 22, and a separator 23. The anode 21 has anode active material layers 21b, 21c including the anode active material alloyed with lithium. The lithium ion secondary battery 1 has a biasing section 20a. The biasing section 20a is arranged on a center of the spiral electrode 20 so as to come in contact with the spiral electrode 20. The biasing section 20a can be contracted in size, and biases the spiral electrode 20 toward outside in a radial direction at least when contracted in size. COPYRIGHT: (C)2011,JPO&INPIT