Performance Improvement by Adding Reduced Graphene Oxides in Brush-Painted NiMoO₄ Nanowires-Polyaniline-Chitosan...

Flexible energy-storage devices are essential for emerging applications such as wearable electronics and soft integrated systems, where mechanical adaptability and long-term stability are required. In this work, a cost-effective brush-painted strategy is developed to fabricate a flexible symmetric supercapacitor based on a NiMoO₄ nanowire/polyaniline/chitosan/reduced graphene oxide composite electrode. The incorporation of reduced graphene oxide significantly enhances the electrochemical performance by improving the electrical conductivity and interfacial charge transfer, leading to more efficient energy storage. The device operates stably within a voltage window of 0.8 V and delivers an areal capacitance of 125.85 mF/cm² at a low scan rate. In addition, it exhibits excellent cycling durability with 94.5% capacitance retention after 10,000 cycles, as well as robust mechanical flexibility, maintaining stable performance under repeated bending conditions. These results demonstrate that the synergistic design of hybrid electrode materials combined with a simple fabrication approach provides an effective route toward high-performance flexible supercapacitors for next-generation wearable and portable electronics.