Unraveling the lithiophilic nature of heteroatom-doped carbons for efficient oxygen reduction in Li-O2 batteries

Abstract Nonaqueous rechargeable lithium-oxygen batteries are promising candidates of the next generation batteries. However, the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) seriously impedes their practical implementations. Herein, heteroatom-doping strategies with respect to lithiophilicity chemistry are investigated to improve the catalytic performance of carbon materials during ORR process through first-principles calculations. The binding energy, electronegativity, electric dipole moment and lithium diffusion barrier are found to be key factors that govern the lithiophilicity of doped heteroatoms. Among all non-metallic elements, pyrrolic nitrogen, carboxylic group oxygen and ketone group oxygen doped graphene nanoribbons exhibit improved thermodynamics and kinetics of ORR, giving rise to uniform deposition of lithium oxides for further favorable OER. This work provides insights into the mechanisms of ORR as well as the formation of lithium oxides and a guidance to design an effectively catalyzed cathode for lithium-oxygen batteries.