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.