Cr-doped VO2(B) has been successfully prepared via the hydrothermal method by adding appropriate amount of Cr(NO3)3·9H2O in the process of synthesis. Combined with some characterization methods such as XRD
XPS
FESEM
EDS
FTIR and so on
the influence of different doping amounts on the phase
morphology
and the electrochemical performance of the Cr-doped VO2(B) sample were investigated. The constant current charge-discharge test result shows that doping appropriate amount of Cr3+ can improve the cycling stability and charge-discharge capacity. When the doping amount was 0.49% and the current density was 0.1C
the initial discharge capacity of the sample was up to 282 mA·h·g-1
about 36 mA·h·g-1 more than that of the sample with no doping
and still more than 189 mA·h·g-1 after 50 cycles
the capacity retention was 67%
better than that of the undoped sample (60.6%) significantly. The results of electrochemical impedance spectra (EIS) and cyclic voltammetry (CV) tests showed that the charge transfer impedance resistance and electrochemical polarization of the sample which doping amount was 0.49% decreased greatly
which further demonstrated its excellent electrochemical properties.