Supercapacitor activity studies of a unique triangular oxo-vanadate-bisphosphonate composite with activated carbon

Electrochemical studies have been performed on a hybrid inorganic-organic oxo-vanadate (IV)-bisphosphonate assembly, viz. (NH4)(2)[H-6((VO)-O-IV)(3)(O){O3P-C(OH)(CH2-4-C5NH4)-PO3}(3)]center dot 26H(2)O [V-3-BP]. The compound has a triangular shaped structure consisting of reduced vanadium (IV) with 1-hydroxo-2-(4-pyridyl) ethylidene-1,1-bisphosphonic acid. Composites of this compound were prepared with activated carbon (AC), viz. AC-V-3-BP, and extensively characterized using various analytical techniques (e.g., FT-IR, TGA, P-XRD, FESEM, EDX, and BET) to study the interaction of V-3-BP with the activated carbon support. Electrochemical properties of AC-V-3-BP were studied, vis-a-vis its supercapacitor behavior, with the electrochemical performance of the composite AC-V-3-BP material tested in 0.1 (M) H2SO4 aqueous electrolytic solution. The composite exhibits a specific capacitance of 140.8 F g(-1) with a specific energy of 19.56 W kg(-1). With such interesting capacitive properties, electrochemical cells prepared with this material were observed to light up red and blue LED bulbs for 90 and 20 s, respectively, suggesting a substantial power density of the materials. The respective electrode prepared from the composite was also observed to retain 79.23% of the electrode stability after 4500 cycles.

Automated summary

In this study, electrochemical investigations were conducted on a hybrid inorganic-organic oxo-vanadate (IV)-bisphosphonate assembly, which was prepared by mixing with activated carbon. The composite material exhibited excellent supercapacitor properties and high power density.