Preparation of a self-healing polyaniline-based gel and its application as a healable all-in-one capacitor

Polyaniline (PANI) prepared by polymerization methods is fragile due to its rigid structure. The preparation of PANI with desirable flexible performance and good ductility still remains a challenge. Here, a self-healing conductive polyacrylamide (PAM)/PANI gel (PPG) with sandwich structure is reported. The surface of PPG is composed of interpenetrating network of conductive PANI and flexible PAM through dynamic hydrogen bonds. PPG exhibits outstanding mechanical property with remarkable tensile strength (0.342 MPa) and elongation at break (277%), as well as efficient self-healing ability. Thus, PPG makes up for the flexible requirement of PANI and can be developed for potential application as an all-in-one solid-state capacitor with high performance. The flexible solid-state capacitor delivers a large capacitance (473 mF/cm2) and extraordinary self-healing performance. This work may provide new insight into the design of flexible PANI and a practical strategy to fabricate mechanically and electrochemically robust gel.