QPHO-graphene: a two-dimensional hexagon-free carbon allotrope as a high-performance anode material for sodium-ion batteries

), a moderate average open-circuit voltage (0.34 V), and a minor lattice alteration (<2%). The existence of solvents having high dielectric constants can facilitate the adsorption and diffusion of Na. In addition, the appearance of a monovacancy defect enhances the binding strength of Na on QPHO-graphene but decreases the ion mobility. These findings make QPHO-graphene a potential anode material for high-performance SIBs.