Bilayer graphene, bilayer GeC and graphene/GeC bilayer heterostructure as anode materials for lithium-ion batteries: First-principles calculations

There is a great effort to develop the high-efficient anode materials for lithium-ion batteries with high stability and mobility. In this paper, we adopt the first-principles calculations to study the electrochemical properties of Li intercalation within bilayer graphene (BLG), bilayer GeC (BLGeC) and graphene/GeC bilayer heterostructure (BLGGeC) as anode materials. Our calculations disclose the following findings: (1) The interlayer is modulated by the stacking patterns and bilayer species. (2) The most energetically favorite intercalation of the Li atom is achieved in BLG with AA stacking because of the lowest adsorption energy. (3) The descending order of energy barriers is BLGGeC > BLGeC > BLG. The low diffusion barriers of BLG (0.025 eV) and BLGeC (0.09 eV) imply their high charging/discharging rates. Finally, the findings underline that the bilayer is a promising anode material and its electrochemical characteristics can be changed by adjusting the stacking configurations and its species.