3D hierarchical AlV3O9 microspheres: First synthesis, excellent lithium ion cathode properties, and investigation of electrochemical mechanism

Despite considered as promising lithium ion cathode materials, the practical applications of vanadium oxide and its derivatives still suffer from the poor kinetics linked to the low electronic conductivity and slow lithium ion diffusion upon cycling. Engineering threedimensional (3D) architectures assembled from low-dimensional nanostructures has recently been of particular interests and proved an effective approach to enhance the electrochemical performances since the high surface area and intrinsic structural stability. Herein, we demonstrate the successful preparation of vanadium-based microspheres via a facile one-pot hydrothermal method. After the post-calcining in air, 3D hierarchical AlV3O9 nanostructures constructed from the assembly of ultrathin nanosheets were successfully obtained. When employed as lithium ion cathodes, the as-synthesized products exhibit outstanding reversible capacity (264 mA h g(-1) retained after 100 cycles) and excellent rate performance (145 mA h g(-1) at a high current density of 5 A g(-1)) for lithium storage. The superior electrochemical performances of the AlV3O9 microspheres can be ascribed to the unique 3D hierarchical morphologies with the ultrathin nanosheets building blocks. (C) 2015 Elsevier Ltd. All rights reserved.