Highly Efficient Polyaniline Trapping and Covalent Grafting within a Three-Dimensional Porous Graphene Oxide/Helical Carbon Nanotube Skeleton for High-Performance Flexible Supercapacitors
Congxu Xuan, Xinyu Li, Zhun Wang, Hao Wu, Tao Tang, Jianfeng Wen, Ming Li, Jianrong Xiao
Abstract
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.