B-Doped Graphene as Catalyst To Improve Charge Rate of Lithium Air Battery

The lithium-air battery as an energy storage technology can be used in electric vehicles due to its large energy density, while its poor rate capability limits its practical usage under large current density. According to first-principles thermodynamics calculation, we predict B-doped graphene can be a potential catalyst to improve the charge rate of lithium-air battery. The lowest-energy reaction pathway for oxygen evolution reaction (OER) is predicted as Li+ -> Li+ -> O-2. The rate-determining step (RDS) is predicted as the O-2 evolution step. B doped graphene can reduce the RDS barrier by 0.40 eV, indicating that charge rate may be significantly improved. B-doping can increase charge transferring of Li2O2 to the substrate by 0.36 e(-), which helps to active Li-O bonds and oxidize O-2(2-) to O-2. We suggest a good OER catalytic substrate that can reduce the O-2 evolution barrier should show p-type surface behavior.