A high-performance rechargeable Li-O₂ battery with quasi-solid-state electrolyte

A novel transparent and soft quasi-solid-state electrolyte (QSSE) was proposed and fabricated, which consists of ionic liquid (PYR₁₄TFSI) and nano-fumed silica. The QSSE demonstrates high ionic conductivity of 4.6×10^-4 S/cm at room temperature and wide electrochemical stability window of over 5 V. The Li-O₂ battery using such quasi-solid-state electrolyte exhibits a low charge-discharge overpotential at the first cycle and excellent long-term cyclability over 500 cycles.