α-CuV2O6 Nanowires: Hydrothermal Synthesis and Primary Lithium Battery Application

We report on the synthesis, characterization, and electrochemical lithium intercalation of alpha-CuV2O6 nanowires, mesowires, and microrods that were prepared through a facile hydrothermal route. The diameters of the as-synthesized alpha-CuV2O6 nanowires, mesowires, and microrods were about 100 nm, 400 nm, and 1 microm, respectively. It was found that by simply controlling the hydrothermal reaction parameters, such as the reagent concentration and the dwell time, the transformation of microrods to nanowires was readily achieved via a "ripening-splitting" mechanism. Electrochemical measurements revealed that the as-prepared alpha-CuV2O6 nanowires and mesowires displayed high discharge capacities (447-514 mAh/g at 20 mA/g and 37 degrees C) and excellent high-rate capability. In particular, the alpha-CuV2O6 nanowires showed capacities much higher than those of alpha-CuV2O6 mesowires, microrods, and bulk particles. The mechanisms for the electrochemical lithium intercalation into the alpha-CuV2O6 nanowires were also discussed. From the Arrhenius plot of lithium intercalation into alpha-CuV2O6 nanowires, the activation energies were calculated to be 39.3 kJ/mol at 2.8 V (low lithium uptake) and 35.7 kJ/mol at 2.3 V (high lithium uptake). This result indicates that the alpha-CuV2O6 nanowires are promising cathode candidates for primary lithium batteries used in long-term implantable cardioverter defibrillators (ICD).