High-Performance Supercapacitor Electrodes Based on Composites of MoS2 Nanosheets, Carbon Nanotubes, and ZIF-8 Metal-Organic Framework Nanoparticles

Supercapacitors have received much attention to meet the growing demand for energy storage devices with high power and energy densities. Despite the efforts, it is still a long way to bridge the gap in the energy densities between batteries and capacitors. In this work, we introduce a hybrid framework for synergetic effects of heteromaterials to improve the performance of supercapacitors. Our composite electrode consists of carbon nanotubes (CNTs) with high conductivity, zeolitic imidazole framework (ZIF) allowing a fast ion diffusion, and molybdenum disulfide (MoS2) bearing a large ion capacity. The hybrid electrode demonstrates exceptional performances, with a specific capacitance over 262 F/g and an energy density of similar to 52.4 Wh/kg at a scan rate of 20 mV/s while keeping a high power density (similar to 3680 W/kg at a scan rate of 100 mV/s). The kinetics analysis reveals that the multicomponent electrode behaves as a hybrid supercapacitor storing energy by not only fast capacitive but also faradaic reactive processes. The CNT-ZIF-MoS2 electrode demonstrates remarkable durability with an outstanding capacitance retention over 10 000 charge/discharge cycles. This work should be beneficial in designing hybrid materials for high-performance supercapacitor devices with an ultralong life span.