Fabrication of a Three-Dimensionally Networked MoO₃/PPy/rGO Composite for a High-Performance Symmetric Supercapacitor

A three-dimensionally interconnected molybdenum trioxide (MoO₃)/polypyrrole (PPy)/reduced graphene oxide (rGO) composite was synthesized via an eco-friendly three-step method. The as-obtained electrode shows a high specific capacity of 412.3 F g^-1 at a current density of 0.5 A g^-1 and a good cycling stability (85.1% of the initial specific capacitance after 6000 cycles at 2 A g^-1 is retained), and these excellent electrochemical performances can be attributed to the unique structure, remarkable electrical conductivity, and the synergetic effects between MoO₃, PPy, and rGO. Furthermore, a symmetric supercapacitor based on a MoO₃/PPy/rGO electrode was assembled to investigate the practical application performance of this material. The results demonstrate a high energy density of 19.8 W h kg^-1 at a power density of 301 W kg^-1. These findings shine a light on the rational design of electrode materials with multicomponents for high-performance supercapacitors.