Coal Tar Pitch-Based Porous Carbon Loaded MoS2 and Its Application in Supercapacitors

In this paper, with coal tar pitch as the carbon source, porous carbon (PC) was prepared by one-step carbonization. To improve the energy density of coal tar pitch-based porous carbon, MoS2@PC was prepared by a hydrothermal method on a PC substrate. The effect of MoS2 loading on the structure and electrochemical properties of the sample was studied. The results show that the specific surface area of the MoS2@PC-0.3 synthesized is 3053 m2 g-1, and the large specific surface area provides sufficient attachment sites for the storage of electrolyte ions. In the three-electrode system, the specific capacitance of MoS2@PC-0.3 at 0.5 A g-1 is 422.5 F g-1, and the magnification performance is 57.3% at 20 A g-1. After 10,000 charge/discharge cycles, the capacitance retention rate of the sample is 76.73%, with the Coulombic efficiency being 100%. In the two-electrode test system, the specific capacitance of MoS2@PC-0.3 at 0.5 A g-1 is 321.4 F g-1, with the power density and energy density being 500 W kg-1 and 44.6 Wh kg-1, respectively. At a current density of 20 A g-1, the capacitance retention rate is 87.69% after 10,000 cycles. This study greatly improves the energy density of PC as the electrode material of supercapacitors.