Ultra-StableHybrid Supercapacitor Enabled by α-MoO3/GrapheneNanohybrids: From Scalable Synthesis to Real-WorldApplications

The increasing demand for efficient and sustainable energy storage has accelerated research into supercapacitors (SCs), which provide high power density and a long cycle life. However, their poor performance remains a major drawback. The layered structure and rich redox chemistry of α-MoO3 make it a promising material for SCs. Despite its advantages, the inherent low conductivity and limited cycling stability of pristine α-MoO3 hinder its further development for SCs. In this work, α-MoO3/graphene nanocomposites were synthesized using a sol–gel method and solution-assisted shear mixing to improve their electrochemical performance. Graphene was incorporated at different weight ratios to investigate its impact on structural integrity and charge storage behavior. The optimized nanocomposite electrode (α-MoO3/G-2) delivered an areal capacitance of 106.02 mF cm–2 at 10 mV s–1. Additionally, an asymmetric supercapacitor (ASC) was also fabricated with the optimized nanohybrid. The device exhibited a high power density (∼3500 W kg–1) and exceptional cycling stability with nearly 100% capacitance retention of 50,000 cycles. These observations illustrate the synergistic contribution of α-MoO3 and graphene and highlight the potential of this scalable composite strategy for advanced energy storage applications.