SM-Doped Ferric Molybdate Gives Oxygen Vacancies and Co-Modified Carbon Nanotubes to Construct High-Energy Supercapacitors

In this paper, nanorods doped with Sm rare earth elements were successfully prepared by the hydrothermal method. In view of the formation of oxygen vacancies by replacing Fe³⁺ with Sm³⁺, it was found that the performance was excellent at the doping ratio of 0.5%, and the growth time was 12 h, and the specific capacity was as high as 1902 F/g at a current density of 1 A/g, and after 700 cycles, there was still 1892 F/g, and the capacitance was guaranteed. The holding rate is 99.1%. When the scanning rate is 10 mV/s, the surface control contributes 56.1% of the current, and when the scan rate is 140 mV/s, the contribution rate of pseudocapacitance behavior control increases to 75%, and the asymmetric device Sm–Fe₂(MoO₄)₃//CNTs is constructed with modified carbon nanotube anode material at a current density of 1 A/g, with a specific capacity of 265 F/g, and the device has been tested for 4000 cycles under the condition of 3 A/g, and the capacitance retention rate is 93.8%. It exhibits a high energy density of 79.3 Wh/kg and a high power density of 760 W/kg. It provides a new idea for the development of supercapacitors.