Polyoxovanadate-Activated Carbon-Based Hybrid Materials for High-Performance Electrochemical Capacitors

Abstract

Two different polyoxovanadates derivatives, K5MnIVV11O32.10 H2O (MnV11) and K7MnIVV13O38.18 H2O (MnV13), have been studied to evaluate their electrochemical performance. These polyoxovanadates were deposited on activated carbon (AC) to prepare AC-MnV11 and AC-MnV13 composites. The electrochemical performance of the AC- MnV11 electrode exhibits the remarkable specific capacitance of 479.73 F g−1 at a current density of 0.6 A g−1, along with incredible specific power and energy of 960 W kg−1. Likewise, the AC-MnV13 exhibits a specific capacitance of 357.33 F g−1 at the current density of 0.6 A g−1 with a specific energy of 71.46 Wh kg−1. Interestingly, the AC- MnV11 could light up the red and yellow color LED bulbs for a duration of 80 and 60 s, respectively, indicating a considerable specific power of the material. The AC-MnV13 electrode shows significantly less lighting up during the 65 and 30 s period with red and yellow LED bulbs.