A mixture of a low molecular weight poly(ethylene glycol) (PEG

Mn=600) and dichloromethane (CH2Cl2) was polycondensated to form a block polymer．The block polymer electrolytes containing lithium salt reacted with an appropriate amount of toluene 2

4-diisocyante(TDI) to form a cross-linked polymer network

with improving the film processability

mechanical and thermal stability properties．Enhancement of the ionic conductivity and electrochemical stability of cross-linked polymer electrolyte was observed by adding lithium bis(trifluoromethane sulfonylimide) (LiN(CF3SO2)2)．In the range of measured temperature

the relationship between conductivity and temperature coincided with Arrhenius formula(σ=Ae-Ea/RT)．One or two activity energy (Ea) values appeared in curves of Arrhenius plots with different salt concentrations．The cross-linked polymer electrolyte exhibited a high ionic conductivity of 1.12×10-5 S／cm at room temperature

and a decomposition voltage at about 5.0 V.