Electrochemical properties and kinetic studies of sulphur-induced oxygen vacancies in hydrothermally synthesized manganese molybdenum oxide

Manganese molybdenum oxide (MnMoO4) has recently garnered significant attention as a promising electrode material for advanced energy storage systems. It is found that the incorporation of oxygen vacancies due to the sulphur doping in MnMoO4led to a larger interlayer spacing, facilitated charge storage kinetics, and maintained structural durability throughout the electrochemical processes. Hence, this work is focused on the hydrothermal synthesis of MnMoO4 with the sulphurinduced oxygen vacancies (S-MnMoO4) by secondary thermal heating processes. Structural and morphological characterizations confirmed the successful inclusion of oxygen vacancies in MnMoO4. Further drop casting S-MnMoO4 on nickel foam revealed significant improvements in electrochemical performance. It showed a specific capacitance of about 1131F g-1 at 1 A/g, which is six-fold that of pristine MnMoO4. S-MnMoO4 demonstrated excellent cyclic stability with 90% of capacitive retention across 5000 cycles and a coulombic efficiency of 98%. These results highlight the potential of S-MnMoO4 as an efficient electrode material for advanced energy storage applications.