Lamellar flower inspired hierarchical alpha manganese vanadate microflowers for high-performance flexible hybrid supercapacitors

Abstract

Hybrid flexible supercapacitors (HFS) offer high power density and stability making them an ideal choice for the energy storage system in wearable devices. In this work, the synthesis of lamellar flower-like alpha manganese vanadate (α-Mn2V2O7) on nickel foam was proposed for efficient and highly stable HFS applications for the first time. The voltammetric characterization indicated that the capacitance contribution of α-Mn2V2O7 is derived from the diffusion-controlled (battery-type, 89.93%) and capacitive controlled (10.07%) mechanisms in aqueous electrolyte (0.5 M KOH). The optimized α-Mn2V2O7 electrode exhibited an impressive specific capacity of 125.6 mAhg−1 (760.3 Fg-1). In the HFS device configuration, the utilization of α-Mn2V2O7 resulted in a remarkable specific capacitance of 35.7 F g−1 with energy, and a power density of 28.4 Whkg−1 and 8.5 kWkg−1, respectively. Furthermore, the α-Mn2V2O7 fabricated device is found to operate in a wide potential window exhibiting remarkable and stable electrochemical performance in the gel electrolyte even under mechanical stress conditions. Importantly, the α-Mn2V2O7 HFS showed an impressive and stable performance over 5000 cycles. The superior specific capacitance performances obtained in the present study are noted to be the best results reported for vanadium-based ternary oxides so far.