Li∕Polymer Electrolyte∕Water Stable Lithium-Conducting Glass Ceramics Composite for Lithium–Air Secondary Batteries with an Aqueous Electrolyte

Abstract

A water-stable Li metal anode with water-stable lithium-conducting glass ceramics, Li1+x+yTi2−xAlxSiyP3−yO12Li1+x+yTi2−xAlxSiyP3−yO12 (LTAP), and a lithium-conducting polymer electrolyte, PEO18Li(CF3SO2)2NPEO18Li(CF3SO2)2N (PEO18LiTFSI)(PEO18LiTFSI) , was proposed as the lithium anode for lithium–air batteries with an aqueous solution at the air electrode. LTAP was unstable when in direct contact with Li metal, and the cell resistance of Li∕LTAP∕Li rapidly increased as a function of the contact time. The Li∕PEO18LiTFSI∕LTAP∕PEO18LiTFSI∕LiLi∕PEO18LiTFSI∕LTAP∕PEO18LiTFSI∕Li symmetrical cell showed no change in the total resistance (around 800Ωcm2800Ωcm2 at 60°C60°C ) over a period of 1month1month . The PEO18LiTFSIPEO18LiTFSI membrane served as a protective interlayer to suppress the reaction between the water-stable glass ceramics LTAP and Li metal effectively. The Li∕PEO18LiTFSILi∕PEO18LiTFSI ∕LTAP∕aqueous LiCl∕PtLiCl∕Pt air cell showed a stable open-circuit voltage of 3.70V3.70V at 60°C60°C for 2months2months . The open-circuit voltage was comparable with that calculated from the cell reaction of 2Li+1∕2O2+H2O=2LiOH2Li+1∕2O2+H2O=2LiOH . The cell exhibited a favorable discharge and charge performance at 0.25mAcm−20.25mAcm−2 and 60°C60°C .