Penta graphene: a superior anode material for Mg-ion batteries with high specific theoretical capacity

Magnesium ion batteries (MIB’s) have the potential to replace the existing lithium ion batteries due to its environment friendly and cost effective nature if anode materials with high theoretical capacity and fast ions diffusion are explored. Using density functional theory, we studied the potential application of penta graphene (PG) as anode material for magnesium ion battery. The unique bonding environment of sp2-hybridizing carbon atoms in PG offers multiple adsorption sites for Mg ions resulting in an ultra-high specific theoretical capacity of 1653.035 mAh/g, low diffusion barriers in the range of 0.04 to 0.30 eV, and low open circuit voltage (OCV) of 0.35 V. Ab-initio molecular dynamics (AIMD) simulation demonstrates the high thermodynamic stability of 37.07% Mg ions loaded PG. The unique structure, low mass density, and the outstanding electrochemical performance of PG suggest it as a potential anode material for Mg-ion batteries.