Inducing Conductive Surface Layer on Nb2O5 via Ar-ion Bombardment: Enhanced Electrochemical Performance for Li-ion Batteries

Niobium pentoxide (Nb2O5) is in the limelight as a negative electrode material for advanced electrical energy storage devices owing to its unique pseudocapacitive behavior. However, its intrinsic poor electronic conductivity restricts its electrochemical performance. In this study, argon-ion bombardment is employed to enhance the interfacial properties of the Nb2O5 negative electrode by introducing highly conductive NbOx (1 ≤ x ≤ 2) species on the electrode surface. The NbOx surface architecture fosters significant improvements in the reversible capacity and rate performance of the argon-ion bombarded electrode than pristine electrodes. Detailed analysis reveals that introducing the surface NbOx layer promotes charge transfer at the electrode surface and breaks the limitations of charge transfer resistance. The result provides a pathway to enhance intrinsic shortness of conductivity and to establish surface modification simultaneously via a simple argon-ion bombardment method, thus achieving the improved electrochemical performance of Nb2O5 and serving as an expedient strategy for augmenting electrode materials for advanced energy-storage applications.