Highly Efficient Polyaniline Trapping and Covalent Grafting within a Three-Dimensional Porous Graphene Oxide/Helical Carbon Nanotube Skeleton for High-Performance Flexible Supercapacitors

Optimizing the electrode structure to achieve efficient material utilization is crucial for high-capacity wearable energy storage devices. Here, a strategy of embedding and covalently grafting polyaniline (PANI) into a three-dimensional porous reduced graphene oxide (RGO)/helical carbon nanotube (HCNT) skeleton was designed to prepare self-supporting flexible supercapacitors (SCs) via an ingenious hydrothermal method, followed by regulation by carbonization. The resulting hybrid aerogel possesses a uniform porous mesh space configuration with excellent flexibility, provides fast ion/electron transmission channels, and maximizes the utilization of pseudocapacitive PANI. Considering the unique spatial configuration of PANI trapped into the porous network, the electrode possesses a remarkable gravimetric capacitance (696.75 F g–1) at 2 A g–1 and an excellent cycling retention (93.57%) after 3500 cycles. Furthermore, the assembled flexible symmetric SC based on carbonized RGO/HCNTs/PANI (CRCP) shows considerable electrochemical performance with a high specific capacitance of 140.1 F g–1 (84.1 F cm–3) at 1 A g–1 (0.6 A cm–3) and a superior energy density of 12.46 W h kg–1 at a power density of 400.36 W kg–1. Moreover, this SC maintains good performance stability at large bending angles. The particular PANI parasitic carbon skeleton-laminated grid design of the CRCP electrode with outstanding capacitance behavior and robust flexibility provides a feasible and efficient preparation technology for fabricating flexible energy storage devices.