Lithium Ion Conductive Membrane for Lithium-Air Batteries

Lithium ion conductive membrane for lithium-air batteries

Wonsung Choi, Dong Joon Lee, Dongmin Im, and Seok-Gwang Doo

Lithium-air secondary battery is characterized by a high specific capacity derived from utilization of lithium metal and oxygen molecule in anode and cathode. To prevent a crossover of anode and cathode material and short circuit, separator membrane is required to be Lithium ion conductive and mechanically strong. We have demonstrated that lithium ion conducting ceramic-based membrane exhibited high conductivity and barrierability. However their brittle nature and large areal weight impeded flexible design of the cell to increase areal capacity.

In this study we adopted polymer electrolyte based membrane. Polyethyleneoxide was impregnated into porous polyethylene to form composite membrane by several methods. Especially thermally melted polyethyleneoxide homogeneously filled nm-scale pore of the porous polyethylene exhibiting ionic conductivity of >10^-3 mS/cm. The polymer electrolyte based membrane allowed 1.2 mAh/cm² of areal capacity of Li-air cell.