CTAB assisted in the synthesis of scandium doped-induced oxygen vacancy porous CoMoO4 positive electrode and MoO3-CNTs negative electrode to construct ultra-high performance supercapacitors

Abstract

In this paper, we present an effective strategy to significantly enhance the electrochemical performance of CMO (CoMoO 4 ) through doping rare earth elements (Sc) to induce the formation of oxygen-generating vacancies, combined with cetyltrimethylammonium bromide (CTAB)-assisted synthesis. Sc doping improves the conductivity and charge transfer rate of the CMO material while enhancing the permeability and ion transport capacity of the electrolyte by inducing oxygen vacancies . Additionally, the introduction of CTAB promotes the formation of a porous structure in the material, increasing the specific surface area and further enhancing electrochemical performance. Experimental results show that the specific capacitance of the CMO-SC-CTAB electrode reaches 1765 F/g at a current density of 1 A/g, significantly higher than that of unmodified CMO (1052 F/g). After 10,000 cycles, its capacitance retention rate is 99.3 %, indicating excellent cycle stability. Meanwhile, molybdenum trioxide (MoO 3 ) was loaded onto carbon nanotubes (CNTs) as the negative electrode material for supercapacitors (MoO 3 -CNTs). This synergistic effect significantly increased the specific capacitance to 1130 F/g at a current density of 1 A/g, far exceeding that of CNTs alone. Importantly, asymmetric supercapacitors (ASCs) assembled with the optimized CMO-Sc-CTAB positive electrode and MoO 3 -CNTs negative electrode exhibited outstanding performance, achieving an energy density of 52.5 Wh/kg and a power density of 13,000 W/kg. These results underscore the great potential of this strategy for high-energy storage applications.