Iron-Doped Molybdenum Sulfide Nanoflowers on Graphene for High-Performance Supercapacitors

Supercapacitors (SCs) are widely acknowledged for their high-power density as energy storage devices; designing electrode materials with both high efficiency and exceptional energy density remains a significant challenge. In this study, a flower-like iron-doped molybdenum sulfide on graphene nanosheets (FMS/G) was synthesized through a simple, efficient, and scalable solvothermal approach. The FMS/G composite demonstrated exceptional performance when employed as both positive and negative electrodes, owing to the effective incorporation of iron into the MoS₂ crystal lattice. This doping induces defects and facilitates abundant redox reactions, ultimately boosting electrochemical performance. The FMS/G composite demonstrates an ultrahigh specific capacitance of 931 F g⁻¹ at 1 A g⁻¹, along with excellent rate capability, retaining 582 F g⁻¹ at 20 A g⁻¹. It also exhibits remarkable cycling stability, maintaining 90.5% of its initial capacitance after 10,000 cycles. Furthermore, the assembled FMS/G-3//FMS/G-3 supercapacitor device achieves a superior energy density of 64.7 Wh kg⁻¹ at a power density of 0.8 kW kg⁻¹ with outstanding cycling stability, retaining 92% of its capacitance after 10,000 cycles. The remarkable capabilities of the flower-like FMS/G composite underscore its noteworthy potential for promoting effective energy storage systems.