Carbon foam@reduced graphene oxide scaffold grown with polyaniline nanofibers for high performance symmetric supercapacitor

To overcome the low capacitance of carbon foam and achieve a high utilization of polyaniline (PANI) pseudocapacitance, graphene nanosheets are filled into carbon foam framework to form a scaffold, and subsequently growing PANI nanofibers to prepare a ternary composite. In this material, carbon foam provides three-dimensional macroporous conductive framework, graphene nanosheets on the carbon foam framework support the deposition of PANI and increase the PANI loading, while much PANI nanofibers contribute a high pseudocapacitance. Therefore, this rationally designed ternary composite not only achieves a high PANI loading of 85.5%, but also exhibits a high specific capacitance and a high utilization of PANI capacitance. As self-supporting electrodes in a symmetrical two-electrode supercapacitor, a high capacitance of 868.5 F g−1 is achieved, in which, the capacitance contributed by PANI reaches 1003 F g−1, more than a half of its theoretical value, furthermore, the capacitance retention is 94.1% after 2000 cycles at 10 A g−1. The design principle of this ternary composite is simple and facile, which can be extended to prepare other nanocomposites containing metal oxides, sulfides, etc. for potential electrochemical applications.