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.