Flexible solid-state supercapacitor based on ternary nanocomposites of reduced graphene oxide and ruthenium oxide nanoparticles bridged by polyaniline nanofibers

The rising demand for wearable electronics has driven research effort tremendously into flexible and compact supercapacitor materials furnished with high energy density, while retaining high-power density, cyclic stability, and durability. In this regard, we, herein, embedded ruthenium oxide nanoparticles (RuO2 NPs) and polyaniline nanofibers (PAni NFs) in the interplanar spaces of reduced graphene oxide (rGO) to prevent their re-stacking to maximize its electric double layer capacitance. It also integrates the pseudo-capacitance of RuO2 and PAni to the ternary nanocomposites (NCs), while the PAni NFs act as interconnecting conducting transmission channel between RuO2 and rGO to regulate charge-transfer kinetics within the system. The resultant ternary NCs display maximum areal capacitance of 1.66 F center dot cm(-2) at a current density of 2 mA center dot cm(-2). A flexible symmetric solid-state device (FSSSD), obtained by assembling the ternary NCs based electrode, attains a specific capacitance of 677 mF center dot cm(-2) with 87 % coulombic efficiency at 2 mA center dot cm(-2) and faster charge transport characteristics (R-ct = 5.5 Omega). The device demonstrates maximum energy density of 60.18 mu W center dot h center dot cm(-2) at a power density of 0.8023 mW center dot cm(-2). The functionality of the device is confirmed by turning on a red LED for up to 180 s with three FSSSDs connected in series.

Automated summary

This study focuses on the development of flexible and compact supercapacitor materials with high energy density and high-power density. By embedding ruthenium oxide nanoparticles and polyaniline nanofibers in reduced graphene oxide, the researchers were able to maximize the electric double layer capacitance and integrate the pseudo-capacitance of the materials within the ternary nanocomposites. The resulting materials exhibited improved charge-transfer kinetics and achieved high capacitance and energy density in a flexible symmetric solid-state device.