Boosting the electrochemical properties of polyaniline by one-step co-doped electrodeposition for high performance flexible supercapacitor applications

Abstract

A facile one-step co-doped electrodeposition method is proposed to prepare polyaniline (PANI) electrodes with improved supercapacitive properties. During electrodeposition of PANI films, sulfuric acid and perchloric acid simultaneously act as dopants to obtain sulfuric acid and perchloric acid co-doped PANI (SP-PANI) electrode. For comparison, single-doped PANI (i.e., sulfuric acid-doped PANI (S-PANI) and perchloric acid-doped PANI (P-PANI)) electrodes are prepared with the same electrodeposition parameters. Electrochemical measurements indicate that the SP-PANI electrodes exhibit substantially improved electrochemical capacitive properties with respect to single-doped PANI electrodes. This improvement can be attributed to the fact that the co-doping changes the morphology, electrical conductivity, and roughness of the PANI films electrodeposited, thus leading to easy pathway for electron transport and increased electroactive surface area. Moreover, we have demonstrated the feasibility of SP-PANI electrodes for use in high performance flexible solid-state supercapacitors. The assembled supercapacitor with SP-PANI electrodes shows high areal capacitance of 149.3 mF cm−2 at 0.5 mA cm−2. It also features high mechanical flexibility, good electrochemical capacitive properties, and superior deformation and electrochemical stability, making it have high application potential in flexible electrochemical energy storage.