Novel synthesis of layered MoS2/TiO2/CNT nanocomposite as a potential electrode for high performance supercapacitor applications

Summary This work is aimed to synthesize hybrid nanocomposite electrode materials for supercapacitor applications. The carbon nanotubes (CNTs) are incorporated into MoS2 as well as TiO2 to form different hybrid electrode materials such as MoS2/CNTs, TiO2/CNTs, and MoS2/TiO2/CNTs in an effort to improve the electrochemical performance. The resulting hybrid electrode materials are examined by SEM, TEM, XRD, XPS, and Raman studies. Cyclic voltammetry and galvanostatic charge‐discharge tests are used to evaluate the specific capacitance and charge‐discharge stability of the synthesized MoS2/TiO2/CNTs. Among the hybrid electrode materials investigated, the MoS2/TiO2/CNTs exhibits superior electrochemical performance with specific capacitance of 1252.57 mA h/g at a scan rate 20 mV/s as compared with MoS2/CNTs (810.53 mA h/g), TiO2/CNTs (607.10 mA h/g), and CNTs (204.35 mA h/g). All electrochemical tests were carried out in a solution of 1 M KOH. The Rct and Rf for the MoS2/TiO2/CNTs electrode were found to be 1.7 Ω.cm2 and 2.1 Ω.cm2, respectively, which were significantly lower than the corresponding Rct (40.2 Ω.cm2) and Rf (51.1 Ω.cm2) for the CNTs electrode, indicating that the MoS2/TiO2/CNTs has a significantly lower overall impedance, which could be one of the key factors responsible for the improved electrochemical performance of the MoS2/TiO2/CNTs. Moreover, this MoS2/TiO2/CNTs hybrid electrode displays good cycling stability with the capacitance retention of 98.83% after 10 000 cycles of charge‐discharge at 1 A/g. The energy density and power density of MoS2/TiO2/CNTs composites are found to be 757.80 Wh/kg and 4546.80 W/kg respectively. Re represents the resistance contribution from the electrolyte, electrode, and the passive film between them. The symbol Rf represented by the semicircle at high frequency are due to the Li+ migration through the solid electrolyte interphase film. The symbol Rct assigned to the charge‐transfer resistance at the electrode/electrolyte interface, which is shown by a semicircle in mid‐frequency region.