Cobalt pyrophosphate nano/microstructures as promising electrode materials of supercapacitor

Cobalt pyrophosphate (Co₂P₂O₇) nano/microstructures (oblong plate, microplate, microflower, and hierarchical architectures) have been successfully synthesized through calcination of NH₄CoPO₄·H₂O nano/microstructures. More importantly, supercapacitive performances of Co₂P₂O₇ nano/microstructures were studied using cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy methods in 3.0 M KOH solution. These results show that Co₂P₂O₇ hierarchical architecture electrodes exhibit high specific capacitance of 367 F?g^?1 at current density of 0.625 A?g^?1 in aqueous KOH solution. Co₂P₂O₇ hierarchical architecture electrodes remain 96.2 % of the initial specific capacitance after 3,000 charge/discharge cycles.