Addition effect of polymer materials, polyvinylpyrrolidone (PVP), polyacrylonitrile (PAN) and polyethylene oxide (PEO) in the electrolyte solutions, ethylene carbonate (EC)-propylene carbonate (PC) (1:1 vol.)/ 0.25 mol/l LiBF4 or Li (CF3SO2)(2)N, was investigated. In the electrolyte solutions containing PVP the charge-discharge current efficiency of lithium on Ni electrode was the highest and the interface resistance between a lithium metal electrode and the electrolyte solution was small during charge-discharge cycle.