Development of integrated V2O5/mSi for supercapacitors: Exhibiting diffusion controlled charge storage dominance

The direct use of silicon is restricted in supercapacitors due to its drawbacks. Seeking some measures to overcome these drawbacks, an integrated micro-sized silicon (mSi) and Vanadium oxide (V2O5NRs@mSi) is developed using hydrothermal method which exhibits a high Faradaic-redox charge storage ability. Development and investigations of hydrothermally grown V2O5 on mSi are reported for the first time. The morphology and microstructural study of fabricated integrate through X-ray diffraction, SEM (EDAX), TEM, FTIR, and Raman spectroscopy revealed that the Vanadium oxide nanorods (NRs) were wrapped around the mSi substrate. The electrochemical study of integrated material as an electrode exhibited a specific capacitance of 441.4 F g−1 at 2 mV s−1 for 2 V voltage window and showed a ∼70 % capacitance retention after 500 cycles. The charge storage kinetics study hinted towards a dominant Faradaic charge storage phenomenon. The observed specific capacitance of integrated V2O5NRs@mSi is comparable with a 3D hierarchical structure of VOx NRs on Silicon nanowires. A low series resistance of 5.62 ohm and a negligible charge-transfer resistance have been observed from Electrochemical Impedance Spectroscopy (EIS) study. Thus, the results establish the mSi as a suitable candidate for developing various integrates with pseudocapacitive materials for energy storage applications.