High energy density asymmetric supercapacitors based on polyaniline nanotubes and tungsten trioxide rods

Abstract

A high energy density asymmetric supercapacitor (ASC) is assembled utilizing polyaniline (PANI) nanotubes as the positive electrode and tungsten trioxide (WO3) rods as the negative electrode. The PANI nanotubes are synthesized via a simple chemical template-free method in the presence of D-tartaric acid as the dopant, and ammonium persulfate as the oxidant, and the WO3 rods are synthesized via a simple hydrothermal process in the presence of sodium carboxymethyl cellulose as a template. The PANI//WO3 ASC device operates with a voltage of 2.0 V and achieved a remarkable specific capacitance of 151 F g−1 at a charge/discharge current density of 0.25 A g−1 and a high energy density of 41.9 Wh kg−1 at a power density of 261 W kg−1. Furthermore, the device showed an excellent charge/discharge cycling performance in 1 M H2SO4 electrolyte, with capacitance retention of 71 % after 10,000 cycles. The high performance of the supercapacitor is due to the unique structure of the electrode materials which can provide high electrode/electrolyte contact area and make electrochemical reaction quickly.