Fabrication of mesoporous TiVN powders and their electrochemical performance

Abstract

The mesoporous titanium vanadium nitride (TiVN) powders were prepared by sol–gel method combined with ammonia reduction nitridation process. The obtained powders were non-stoichiometry TiVN solid solution phase with different valence of Ti and V ions as determined by X-ray diffraction and X-ray photoelectron spectroscopy. The energy dispersive X-ray spectroscopy results showed that the N, Ti and V elements were homogeneously distributed in the TiVN powders. Scanning electron micrographs revealed that the diameter of TiVN powders was in the range of 1–2 µm. It was found that the TiVN powders possessed BET surface area of 24.3 m²/g and average pore size of 19.8 nm. A maximum specific capacitance of 231 F/g was tested by Galvanostatic charge–discharge and retained 99.4% of initial capacitance after 2000 cycles. While the capacitance of TiN and VN powders were only 93 and 221 F/g. Cyclic voltammetry and Electrochemical impedance spectroscopy measurements were also performed. The intrinsic resistance of the mesoporous TiVN powders electrodes was 0.9 Ω, which was smaller than that of the TiN (1.1 Ω) and VN (1.1 Ω). It indicated that the mesoporous TiVN powders with the uniform distribution of each element could also effectively improve the electrochemical properties of electrodes compared with TiN and VN powders.