Synthesis of Lithium Silicon Vanadium Oxide by Solid-State Reaction with Microwave-Assisted Method and Electrochemical Characterization

Abstract

In this research, the synthesis of lithium silicon vanadium pentaoxide compounds is performed by the solid-state reaction and heated by a microwave. This combines the advantages of a solid-state reaction and the microwave method. The precursors were lithium nitrate, vanadium pentaoxide, and silica from rice husk ash. The conditions were studied according to grinding time and microwave heating. Each condition was examined for electrochemical properties by cyclic voltammetry. The grinding time at 6 hr and heating at 600 W for 5 min provided the highest specific capacitance of 376 F g⁻¹. The product morphology was determined to be irregular in shape by scanning electron microscopy. The X-ray diffraction and transmission electron microscopy results identify that the product was Li_3.6Si_0.6V_0.4O₄. X-ray absorption near edge structure technique found the oxidation of vanadium was V⁴⁺ and V⁵⁺. Fourier transform infrared spectroscopy and resonance Raman spectroscopy exhibited the bonds of Si − O, Li − O, V − O − V, V = O and Si − O−Si.

Keywords:

• Microwave-assisted
• solid-state reaction
• lithium vanadium silicon oxide
• supercapacitors

Acknowledgments

The authors would like to thank National Research Council of Thailand (NRCT) for the financial support and Synchrotron Light Research Institute (Public Organization) (BL5.2), Nakhon Ratchasima, Thailand.