First Principles Study of Nitrogen Boron Doped Graphene and Co Doped Graphene as the Potential Catalysts in Nonaqueous Li O2 Batteries
In this work, we perform a first principles study of graphene, nitrogen boron doped graphene, and codoped graphene as the potential catalysts in nonaqueous lithium oxygen (Li O2) batteries. Among the samples studied, boron doped graphene exhibits the lowest discharge and charge overpotentials, suggesting that boron doped graphene is the best catalyst for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in nonaqueous Li O2 batteries. Another significant finding is that codoping of nitrogen and boron atoms does not enhance the ORR/OER in the presence of lithium atoms, indicating that the synergistic effect in the presence of protons does not appear in nonaqueous Li O2 batteries. This behavior is attributed to the fact that the existence of lithium atoms can change the most stable adsorption sites and adsorption energies of intermediates. Finally, on the basis of our calculation results, we propose that the adsorption energy of intermediates in the rate determining step (RDS.