A versatile integrated rechargeable lead dioxide-polyaniline system with energy storage mechanism transformation

A versatile integrated rechargeable hybrid system by engineering a fibrous polyaniline negative electrode is proposed to essentially solve the existing problems of lead-acid battery, which include the dendrite formation, poor cycle stability, water loss, environmental hazards derived from the electrochemical functionality of negative lead. We demonstrate that polyaniline negative electrode could result into the boosting performance of the integrated system due to the reaction mechanism of polyaniline, which involves the transition of leucoemeraldine/polaronic emeraldine together with the doping/dedoping of dopant. As a result, the integrated system delivers an admirable specific capacity, effectively avoids the sulfuric acid salinization, presents considerable power and energy density, and distinctly enhances the cycle stability. Meanwhile, the reaction kinetics of the hybrid system is also investigated and the controllable mechanism transformation from the pseudo-capacitive to battery-type behavior could be realized by regulating the mass ratio. In addition, low employment of lead substances further increases its ecological acceptability, reflecting a promising prospect of application as an efficient energy storage system in the future. Moreover, the strategy features simple configuration and easy operation without altering the original structure, which could further bridge the gap between lead-acid battery and supercapacitor.