Designing an All-Solid-State Sodium-Carbon Dioxide Battery Enabled by Nitrogen-Doped Nanocarbon

All-solid-state sodium–carbon dioxide (Na-CO₂) battery is an emerging technology that effectively utilizes the greenhouse gas, CO₂, for energy storage with the virtues of minimized electrolyte leakage and suppressed Na dendrite growth for the Na metal anode. However, the sluggish reduction/evolution reactions of CO₂ on the solid electrolyte/CO₂ cathode interface have caused premature battery failure. Herein, nitrogen (N)-doped nanocarbon derived from metal–organic frameworks is designed as a cathode catalyst to solve this challenge. The porous and highly conductive N-doped nanocarbon possesses superior uptake and binding capability with CO₂, which significantly accelerates the CO₂ electroreduction and promotes the formation of thin sheetlike discharged products (200 nm in thickness) that can be easily decomposed upon charging. Accordingly, reduced discharge/charge overpotential, high discharge capacity (>10 000 mAh g^–1), long cycle life, and high energy density (180 Wh kg^–1 in pouch cells) are achieved at 50 °C.