High-Performance Supercapacitor Electrodes Based on Composites of MoS<sub>2</sub> Nanosheets, Carbon Nanotubes, and ZIF-8 Metal–Organic Framework Nanoparticles
Duncan Houpt, Jaehoon Ji, Daniel D. Yang, Jong Hyun Choi
Abstract
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 ∼52.4 Wh/kg at a scan rate of 20 mV/s while keeping a high power density (∼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.