A study of the most condensed configuration of oxocarbon molecule adsorption on graphene surface: A first-principle investigation

In our previous study, oxocarbon molecule C ₆ O ₆ was adopted as the active material for the electrode of Li-ion batteries. The cycling performance of organic electrodes could be increased by polymerization or adsorption on backbone materials like graphite or graphene. We choose the second method in our research system and have proven this system has at least 155 mAh/g theoretical capacity. In this research, we systematically investigate 11 different kinds of adsorption densities of C ₆ O ₆ on mono-graphene sheet by density functional theory. Lenard-Jones potential is introduced to calculate the interaction on X-Y plane and adsorption and distortion energy are elucidated separately. A proper graphene layer distance of ∼7.7 Å is determined. The results imply the maximum theoretical capacity is ∼290 mAh/g with relative lowest distortion. This combined material possess 2.04 V average voltage and improved conductivity, which can be compared to traditional in-organic materials like LiCoO ₂ or LiFePO ₄ .