LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To prevent deposition of dendrite to the lead wire connecting part of a negative electrode current collector by constituting the separator part between the opposed end parts of a positive electrode plate containing transition metal oxide and the lead wire connecting part of the negative electrode current collector positioned on the outer peripheral side of a spiral plate group of a negative electrode plate containing a carbon material capable of doping/depoping lithium so as not to pass lithium ions. SOLUTION: A strip positive electrode plate 1 having a positive electrode material layer 1b on a positive electrode current collector 1, a strip negative electrode plate 2 having a negative electrode material layer 2b on a negative electrode current collector 2b and a separator 3 such as an ion transmissive porous synthetic resin sheet, constitute a spiral plate group. A part of an inside winding layer 3b of the separator 3 between the negative electrode side lead wire connecting part 2c of the exposed one end part of the negative electrode current collecting body 2 on the outer peripheral side and the lengthwise directional end part 1d of the positive electrode plate 1, is formed as the nonporous checking part 3c by thermal contraction or the like so as not to pass a lithium ion. Even if the negative electrode plate 2 becomes deposition potential or less of lithium at rapid charge time, the lithium does not deposit in the negative electrode side lead wire connecting part 2c.