High-performance supercapacitors based on silver nanoparticle–polyaniline–graphene nanocomposites coated on flexible carbon fiber paper

Abstract

For practical use of supercapacitors, new electrode materials are needed with high ionic adsorption capacity at the solid–liquid interface, fast and reversible surface redox reaction, and fast charge transfer. In the current study, we produce a new hybrid material of electrochemical double layer capacitive graphene, pseudocapacitive polyaniline (PANI) and highly conductive silver nanoparticles (AgNPs). The nanocomposite of AgNP–PANI–graphene in a weight ratio of 0.1 : 1 : 1, coated on flexible carbon fiber paper (CFP), exhibits high specific capacitance and capacity retention. At an applied current density of 1.5 A g−1, the maximum specific capacitance of AgNP–PANI–graphene/CFP is 828 F g−1, which is about 4.0-, 2.2-, 1.6-, and 1.5-fold higher than those of graphene/CFP, PANI/CFP, AgNP–PANI/CFP, and PANI–graphene/CFP, respectively. The capacity retention of AgNP–PANI–graphene/CFP after a charge–discharge test having 3000 cycles is 97.5% of the original specific capacitance. This was 4.4, 12.9, 14.5, and 23.5% more stable than PANI–graphene/CFP, graphene/CFP, AgNP–PANI/CFP, and PANI/CFP, respectively. An 0.8′′ × 6′′ all-solid-state supercapacitor device composed of AgNP–PANI–graphene/CFP exhibited a specific capacitance of 142 F g−1 measured at an applied current density of 1.5 A g−1 and a wide working potential of 6.2 V after consecutive charge–discharge tests over a 16.40 h period. This fully charged supercapacitor could power a 3 V motor for 7.30 min.