High performance battery–supercapacitor hybrid energy storage system based on self-doped polyaniline nanofibers

Nanostructured self-doped polyaniline (SDPA) is prepared from an aqueous solution of aniline and m-aminobenzoic acid using an electrochemical method onto a stainless steel electrode. This electrode employed as a positive shared electrode in the construction of a hybrid battery–supercapacitor energy storage system AC/SDPA/Zn. This hybrid system is constructed using a parallel combination of an asymmetric supercapacitor (AC/SDPA) and a secondary battery (Zn/SDPA) in a single cell configuration and same electrolyte. Different electrochemical methods including cyclic voltammetry, galvanostatic charge–discharge and rate charge–discharge studies are carried out to characterize electrochemical performances of the hybrid system. Based on the obtained results, the hybrid system shows specific capacity, specific energy, specific power and maximum power values of 215 Ah kg−1, 204 Wh kg−1, 863 W kg−1 and 8909 W kg−1, respectively, at a current density of 2.5 mA cm−2.