A renewable biopolymer cathode with multivalent metal ions for enhanced charge storage

Abstract

A ternary composite supercapacitor electrode consisting of phosphomolybdic acid (HMA), a renewable biopolymer, lignin, and polypyrrole was synthesized by a simple one-step simultaneous electrochemical deposition and characterized by electrochemical methods. It was found that the addition of HMA increased the specific capacitance of the polypyrrole–lignin composite from 477 to 682 F g⁻¹ (at a discharge current of 1 A g⁻¹) and also significantly improved the charge storage capacity from 69 to 128 mA h g⁻¹.