Hydrogen adsorption on Li metal in boron substituted graphene: ab initio approach

The characteristics of hydrogen adsorption on Li metal atoms dispersed on graphene with boron substitution were investigated for Li clustering, hydrogen bonding characteristics and open metal states of Li adatom by using density functional theory calculations. It is found that Li atoms are well dispersed on boron substituted graphene and can form the (2 × 2) pattern because clustering of Li atoms is hindered by repulsive Coulomb interaction between Li atoms. One Li adatom dispersed on the double side of graphene can absorb up to 8 hydrogen molecules corresponding to 13.2% hydrogen storage capacity. In addition, adsorption behaviors of non-hydrogen atoms such as C, B, and O₂ are calculated to find whether Li atom can be remained as open metal state in boron substituted graphene.