All-Solid-State Sodium-Ion Batteries with Organic Quinone Cathodes and Na₃PS₄ Electrolyte for Grid-Scale Storage

Abstract

Grid-scale energy storage demands batteries that are safe, low-cost, and made from earth-abundant elements. We report an all-solid-state sodium-ion battery (ASS-SIB) using anthraquinone-grafted carbon nanotube (AQ-CNT) cathodes and a cold-pressed Na₃PS₄ solid electrolyte. The AQ-CNT cathode delivers a reversible capacity of 218 mAh/g at C/5 rate with 89% retention after 1,000 cycles at 60°C. The full cell achieves an energy density of 185 Wh/kg at the stack level, with raw material costs estimated at $32/kWh — well below the $100/kWh target for grid competitiveness. Operando Raman spectroscopy reveals a two-electron quinone/hydroquinone redox mechanism with minimal structural change, explaining the exceptional cycling stability.