Novel capacitance properties of polyaniline with branch-like chains

Abstract

A novel capacitance performance of polyaniline (PANI) with branch-like chains is investigated firstly at the molecular level in this paper. The PANI with branch-like molecular chains has been synthesized by a simple template-free polymerization method. The morphology and structure of the PANI have been studied by using scanning electron microscopy (SEM) and Fourier transform infra-red spectroscopy (FTIR). The results indicate that the branch-like chains disintegrate into small linear fragments during galvanostatic charge-discharge cyclings, with a concomitant increase of conductivity and decrease of the internal resistance (IR), which is consistent with a stronger π-π molecule conjugation inside the small linear PANI fragments. Therefore, the branch-like PANI exhibits a novel capacitance property with the specific capacitance rises up to 73-fold (from 4 to 294 F g−1) after 107 charge-discharge cycles. This work provides a new pathway to design and prepare high-quality PANI-based supercacitors with novel molecular chain structures.