Porous inorganic filler Li4.7Ag1.63GeS4.8 in PEO electrolyte effectively inhibits Li dendrites for all-solid-state Li metal batteries

The newly created porous inorganic particles Li4.7Ag1.63GeS4.8 as filler are added into poly (ethylene oxide) (PEO) with LiTFSI salt, which greatly improves the electrochemical stability of solid-state PEO-based electrolytes against Li metal in a working battery. Due to many pores and channels in the filler, Li dendrites would grow along these channels thereby effectively inhibiting their fast spread in PEO matrix and retarding the short circuit on account of the penetration of Li dendrite. The Li+ conductivity of this solid-state electrolyte membrane could be 1.36 × 10-4 S/cm at 40 °C. The fabricated symmetrical Li metal cells could cycle above 550 h at 0.05 mA/cm2 and corresponding LiFePO4/Li all-solid-state cells have an excellent cycling stability of 160.65 mAh g-1 specific capacity after 200 cycles with 99.93% columbic efficiency at 50 °C environment.