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

Abstract

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.