All-Solid-State Garnet Type Sulfurized Polyacrylonitrile/Lithium-Metal Battery Enabled by an Inorganic Lithium Conductive Salt and a Bilayer Electrolyte Architecture

An all-solid-state garnet Li-S cell with a solid-state sulfur cathode is fabricated by mixing sulfurized polyacrylonitrile (SPAN) with molten lithium bis(fluorosulfonyl)imide (LiFSI) and nano graphene wire (NGW) to improve interfacial contact and ionic and electronic conduction throughout the solid cathode structure. This solid SPAN/LiFSI/NGW cathode was deposited on a dense/porous bilayer garnet structure impregnated on the porous anode side with Li metal and obtained an average discharge capacity of 1400 mAh/g at a current density of 0.167 mA/cm2 (0.1C) for over 40 cycles and of 437 mAh/g at 0.84 mA/cm2 (0.5C) for over 200 cycles for our Li-S cell at 60 °C. This new cathode architecture is a significant advancement toward the development of high-performance all-solid-state Li-S batteries.