Commercial Cellulosic Paper-Based Solid Electrolyte for High-Temperature Lithium–Sulfur Batteries

Solid-state lithium-sulfur (Li-S) batteries show promise for future electric mobility due to their high energy density potential. However, high internal impedance, Li polysulfide shuttling, and dendrite formation exist. Herein, we present a Li-rich cellulosic solid-state electrolyte (SSE) that, when paired with a sulfurized polyacrylonitrile (SPAN) cathode, leads to durable Li-S batteries for use in the room temperature to 50 °C range. Our cellulosic SSE is prepared via a scalable, viable method and exhibits high area-normalized conductance (24.4 mS cm^-2) and Li-ion transference number (0.76) at 50 °C. After 150 cycles at 50 °C, solid-state Li-S half cells retained 82.2% capacity. Full cells with a thin Li foil anode and an N/P ratio of 4.92 showed stable cycling at both room temperature and 50 °C for nearly 40 cycles, attributed to the excellent conformability of the paper-derived SSE. These results place our work among the top few for SPAN-based all-solid-state Li-S batteries.