Optimizing the supercapacitive performance of MoS2 by multivalent tungsten ion doping

Official URL: https://dx.doi.org/10.1039/d6nr00405a

This study examined the effect of tungsten doping on the structural and electrochemical performance of molybdenum disulfide (MoS2) in symmetric supercapacitor devices. MoS2 nanoflowers with different W contents (0–1%) were synthesized by a hydrothermal method and characterized using XRD, Raman, PL, EPR, SEM, and BET analysis. Tungsten incorporation induced lattice distortions, sulfur vacancies, and enhanced defect-assisted charge transport, while retaining the layered morphology. Electrochemical measurements revealed a combination of electric double-layer and pseudocapacitive behavior with the MoS2:W0.7 electrode material delivering the highest performance. This device achieved a specific capacitance of 848 F g−1 at 10 mV s−1, an energy density of 117.8 Wh kg−1, a power density of 2121 W kg−1, and excellent cycling stability, retaining 97% of its capacitance. The results demonstrate that W doping introduces additional electroactive sites and improves conductivity, highlighting a simple strategy to enhance the energy-storage capability of MoS2-based materials for supercapacitor applications.