Hybrid electrodes based on polyoxometalate-carbon materials for electrochemical supercapacitors

摘要

Hybrid electroactive materials based on polyoxometalate-adsorbed activated carbons have been developed for the first time as electrodes for supercapacitors. By combining the double layer capacitance of a high-surface area material with the reversible redox activity of a polyoxometalate (POM), enhanced electrochemical performance is obtained. In this paper, phosphomolybdic acid H 3PMo 12O 40 (PMo 12) was anchored to an activated carbon providing 160 F g - 1 and 183 F g - 1 for the positive and negative hybrid electrodes, respectively (at 2 A g - 1), substantially larger than the 136 F g - 1 of the unmodified activated carbon. This translates to a cell capacitance for the AC-POM supercapacitor is 45 F g - 1 versus 35 F g - 1 for the AC supercapacitor, i.e. a 29% increase after POM integration into the AC matrix.