Asymmetric Supercapacitor Performance Enhancement Through Fe-Doped MoS₂ Nanosheets Synthesized via Hydrothermal Method

As modern civilization’s energy demands continue to rise, the need for efficient renewable energy solutions becomes increasingly critical. In addressing this challenge, our research explores the potential of newly developed iron (Fe)-doped molybdenum disulfide (MoS2) thin-film electrodes, synthesized through a simple hydrothermal method, as a promising energy storage device. By systematically varying the Fe doping levels, we aim to elucidate the relationship between Fe content and the structural, morphological, and electrochemical properties of the MoS2 electrodes. The optimized FM-3 electrode exhibited a remarkable areal capacitance of 8.25 F/cm2 at a current density of 10 mA/cm2 with an energy density of 0.22 mWh/cm2 and a power density of 2.2 mW/cm2. Furthermore, the FM-3 demonstrated impressive long-term cycling stability, retaining 85.58% of its initial capacitance after 10,000 charge–discharge cycles. To further explore practical applicability, an asymmetric pouch-type supercapacitor device was assembled using an FM-3 electrode and activated carbon. The device achieved an impressive areal capacitance of 0.43 F/cm2 at a current density of 20 mA/cm2, delivering an energy density of 0.133 mWh/cm2 and a power density of 7.5 mW/cm2. The exceptional performance of the FM-3 electrode can be attributed to the enhanced diffusion rate, charge transfer efficiency, and better carrier mobility induced by Fe doping. This work not only highlights the significant electrochemical performance improvements of Fe-doped MoS2 electrodes but also demonstrates their potential for scalable energy storage solutions, making a valuable contribution to the field of next-generation energy storage technologies.