| 摘要 |
PROBLEM TO BE SOLVED: To stabilize electrolyte retaining property and enhance durability for charging and discharging cycle by using a copolymer containing a polymerization unit base on tetrafluoroethylene and a polymerization unit based on hexafluoropropylene in a specific ratio as a matrix for the electrolyte and by using a solvent which can dissolve lithium salt and salt. SOLUTION: Electrolyte of a lithium battery has as a matrix a copolymer containing a polymerization unit based on tetrafluoroethylene for 30-70 wt.% and a polymerization unit based on hexafluoropropylene for 8-50 wt.%. Solute of lithium salt and a solution which can dissolve lithium salt are included. A melting point of the copolymer is preferably not less than 50 deg.C. Solvent for the lithium salt is preferably carbonic estel such as propylene carbonate, dimethyl carbonate and the like. It is preferably that the solution in which the lithium salt is dissolved in the solvent is contained in the polymer electrolyte for 30-80 wt.%. Also, a molecular weight of the copolymer used is preferably 10,000-1,000,000. |
