Construction of High-performance Hybrid Supercapacitor Devices by V-doped Flower-like Fe₂(MoO₄)₃ and SnO₂/CNTs

In this work, we present for the first time an innovative strategy to construct high-performance hybrid supercapacitors through the synergistic optimization of vanadium-doped self-supported three-dimensional Flower-like Fe₂(MoO₄)₃ anodes and SnO₂/CNTs composite anodes. The V-doped Fe₂(MoO₄)₃ anode synthesized by a microwave-assisted hydrothermal method combines vanadium doping-induced oxygen vacancies, lattice distortion effects and self-supporting properties of the three-dimensional floral structure, which enhances the specific surface area of the material to 190.58 m²/g, and obtains a high specific capacitance of 2,157 F/g at a current density of 1 A/g, and undergoes a 15 A/g After 10,000 cycles at 15 A/g, the capacitance retention rate is still 98.2 %. To address the limitations of traditional anode materials, SnO₂/CNTs composites significantly reduce the charge transfer resistance (5.61 Ω) and enhance the multiplicity performance by combining the high theoretical capacity of SnO₂ with the three-dimensional conductive network of CNTs. Based on this, the V-Fe₂(MoO₄)₃//SnO₂/CNTs hybrid supercapacitor achieves a high energy density of 151 Wh/kg at 3 A/g, which is a 30-60 % enhancement over the conventional molybdate capacitor, and maintains 96.2 % capacitance stability after 10,000 cycles. This provides a new idea for the development of energy storage devices with high energy density and long cycle life.