The microdefects and enhanced electrochemical performances of nano-VO2(B) induced by Mg doping

The Mg-doped VO2(B) nanorods were prepared by solvothermal and further heat treatment method. The effects of Mg doping on the structure, surface morphology, microdefects and electrochemical performances of the samples were comparatively investigated. The prepared samples were well crystallized in monoclinic structure, yet nonetheless there was a slight lattice expansion caused by Mg doping in the Mg-doped VO2(B) nanorods. With the increase of Mg doping concentration x (0.000, 0.005, 0.015, 0.030), the average grain size of the samples firstly decreased and then increased, and the grain size was the smallest when x was 0.015. Positron annihilation lifetime measurements revealed that there were vacancy-type defects in all the samples. The defect concentration and size in the Mg-doped VO2(B) samples were affected by Mg doping contents. The moderate amount of Mg doping can improve the structural stability and cycling performance of the samples. The Mg-doped VO2(B) sample with x = 0.015 showed the better cycling performance, which provided great potential applications in the electrode material of storage batteries.

Automated summary

The effects of Mg doping on the structure, morphology, defects, and electrochemical performances of Mg-doped VO2(B) nanorods were investigated. The results showed that moderate Mg doping improved the structural stability and cycling performance of the samples.