Donor-Node-Acceptor Ambipolar Conducting Polymer Electrode Materials for Wide-Voltage and High-Stability Supercapacitors

Supercapacitors are crucial energy storage devices on account of their high-power density. However, the low energy density of supercapacitors leads to a narrow range of applications. In this work, a donor-node-acceptor (D-n-A) ambipolar conductive polymer was synthesized, which displays a wide potential window (positive electrode: 1.5 V; negative electrode: -2 V vs Ag/Ag+) with good conductivity. Such electrochemical behaviors are brought about by the unique electrons inside the molecule, including the local delocalization of molecular charges and the effect of withdrawing electrons. A symmetrical supercapacitor assembled by this material exhibits a high energy density (23.8 mWh/cm3), high power density (14.99 W/cm3), and less energy density decay as power density increases, which maintains a high level in the same type of supercapacitor. In addition, the device maintains a high cycle stability of 81% over 10,000 cycles. This study provides an idea for developing high energy density supercapacitors.