Microdefects evolution and electrochemical performance modulation of Mn doped VO2(B) nanorods

A series of nano-V 1- x Mn x O 2 samples ( x = 0–0.035) were prepared by a simple solvothermal method. XRD patterns and the Rietveld refinement results of V 1- x Mn x O 2 samples showed that Mn ions were incorporated into the V sites during the solvothermal process. XPS results indicated that the valence state of Mn ion was a mixed state of Mn 2+ , Mn 3+ and Mn 4+ . The corresponding relationship between the diameter, specific surface area and electrochemical performances of V 1- x Mn x O 2 nanorods was studied. It can be found that Mn doping promoted the insertion of K + ions into the electrode material and improved the conductivity, discharge capacity and cycle stability, which was due to more defects induced by Mn doping. The x  = 0.020 sample had the largest specific capacitance (the 88% capacity retention rate after 550 cycles at 0.1 A·g −1 ) due to the improvement of structural stability by Mn-ion doping. These results provide great potential applications for nano-VO 2 (B) in the cathode material of lithium-ion battery and supercapacitor .