Effect of charging protocol and carbon electrode selection in Na–O2 batteries

Abstract Nonaqueous sodium- and lithium-oxygen batteries are of interest because their high theoretical specific energies relative to state-of-the-art Li-ion batteries. However, several challenges limit rechargeability, including instability the carbon electrode electrolyte with reactive oxygen species formed during cycling. This work investigates strategies improve cycling efficiency Na–O 2 system minimize irreversible degradation materials. We show that charging cells a constant current/constant voltage (CCCV) protocol is promising technique made possible by slight solubility sodium superoxide in nonaqueous electrolytes. In addition, type has significant impact on cell performance efficacy protocol. Graphitic electrodes coupled CCCV demonstrate higher reversibility, more efficient evolution, less outgassing than conventional using porous paper only current charge. Graphical abstract