Hybrid Supercapacitor Electrodes Made of Carbon Nanotubes, Zeolitic Imidazole Framework and Molybdenum Disulfide

Supercapacitors are electrochemical energy storage devices that are developed to bridge the gap between batteries and capacitors. Despite the progress over the years, the energy densities of supercapacitors are not yet comparable to those of lithium-ion batteries. This work introduces a hierarchical framework composed of hetero-materials for synergetic effects. We prepared an electrode with a highly conductive network of carbon nanotubes (CNT) encapsulated by zeolitic imidazole framework (ZIF) allowing a fast ion diffusion and molybdenum disulfide (MoS₂) offering a large ion capacity. The hybrid electrode shows exceptional performances, with a specific capacitance over 262 F/g and an energy density of ~52 Wh/kg at 20 mV/s while maintaining a high-power density. Our analysis suggests that the ternary network behaves as a hybrid supercapacitor through both double-layer capacitive and faradaic reactive mechanisms. We monitored the outstanding durability with 95 % of the capacitance retention over 30,000 cycles. The findings from this study could help develop highly efficient energy devices.