posted on 2021-12-24, 12:35authored byDuncan Houpt, Jaehoon Ji, Daniel Yang, Jong Hyun Choi
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.