LITHIUM ION SECONDARY BATTERY, AND METHOD FOR PRODUCING GEL ELECTROLYTIC SOLUTION

摘要

PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery which has a cell having a high mechanical strength and including a gel electrolyte and enables the large reduction of cell expansion in a cyclic process, and in which the gel electrolyte includes, as monomers, a modified polyvinyl alcohol having a large average molecular weight and a derivative thereof.SOLUTION: A lithium ion secondary battery comprises: a liquid electrolyte; a monomer; a crosslinker; and an initiator. The weight percentages of the respective components are as follows: the liquid electrolyte is 90-99.4%; the monomer is 0.5-3%; the crosslinker is 0.25-0.6%; and the initiator is 0.1-1.5%. The monomer includes a modified polyvinyl alcohol and a derivative thereof, of which the average molecular weight is 5×10to 15×10g/mol.