Promoted Electrochemical Performance of β-MnO2 through Surface Engineering

Different crystal facets with different surface atomic configurations and physical/chemical properties, will have distinct electrochemical performances during their surface/near-surface redox reactions, and it's important to realize controllable synthesis of high active surfaces for electrode materials. Herein, using first-principle calculations, the electrochemical performances of different surfaces for beta-MnO2 were investigated. Higher surface adsorption pseudocapacitance and lower ion diffusion barrier from surface to near-surface, make {001} surface of beta-MnO2 superior to other surfaces when acting as electrode material. Moreover, beta-MnO2 with large percentage of {001} surface was predicted to be obtained through surface F terminating. F-termination will decrease the surface energy of {001} surface while suppressing the growth of {110} surface, which is demonstrated as the surface with much lower electrochemical performances. This work might provide a feasible strategy to synthesize anticipated surfaces with high electrochemical performance for transition metal oxides.