Quinone functionalized highly porous polymer as cathode material for Mg ion batteries: A DFT study

Magnesium ion batteries (MIBs) are one of the vital strategies for the next-generation energy needs and computational simulations can accelerate this search many folds. In this paper, we suggest a novel cathode material, quinone functionalized hexahydroxytriphenylene (HHTP) and diphenylbutadiynebis (boronic acid) (DPB) based porous polymer (QHHTP-DPB), for Mg-ion batteries. The material is stable with highly porous structure and strong affinities for Mg ions to attach to C=O sites of the quinone rings. The single unit of the polymer layer can be fully loaded with Mg ions at various active sites exhibiting a specific theoretical-capacity of 720.48 mAhg−1 and positive low open-circuit voltage of 0.39 V. No structural variation is observed in QHHTP-DPB and a larger decrease in the HOMO-LUMO gap occurs after Mg ions adsorption onto the polymer, reflecting the better cycling performance and high capacity for Mg ion batteries. These results show that our designed quinone functionalized HHTP-DPB porous polymer could be a futuristic cathode material for MIBs and needs further theoretical and experimental investigations.