Nitrogen and Sulfur Co-doped Biomass-Derived Porous Carbon Electrodes for Ultra-High-Performance All-Aqueous Thermally Regenerative Flow Batteries

Developing high-performance electrodes for the all-aqueous thermally regenerative ammonia battery (ATRB) system, serving as superior substitutes for commercial carbon cloth electrodes, is anticipated to enhance performance, yet it lacks effective guidance and research. In this work, theoretical analysis is initially used to evaluate the effective conversion and adsorption capacity of nitrogen and sulfur co-doped carbon with respect to copper ion by density functional theory calculation. On the basis of this concept, the nitrogen and sulfur co-doped biomass-derived porous carbon electrode (DGC) is prepared using natural porous carbon materials and thiourea. Compared with commercial carbon cloth electrodes, ATRB with DGC achieves a significant improvement in maximum power density of 49.2%. Via optimization of the doping conditions, the active sites can be effectively regulated to boost charge transfer at the reaction interface. Furthermore, the rapid charge transfer can match the excellent mass transfer performance, generating an impressive net power density of 847.5 W/m2.