Development of CoTe₂, CoS₂, and CoSe₂ Electrode Material for the Asymmetric Supercapacitors

Supercapacitors play a crucial role in electrical energy storage and conversion applications today due to their high power density and ability to integrate with various energy conversion devices. Many efforts have been made to address issues such as low energy density and finding efficient electrode materials to achieve high capacitances. Layered transition metal dichalcogenides have shown great potential in energy storage applications because of their numerous active edges, diverse electrochemical kinetics, and unique sandwich structure. Therefore, researchers have been exploring a meticulous method to formulate multiscale CoS₂, CoSe₂, and CoTe₂ nanoarchitectures to enhance the storage characteristics of supercapacitors. This study employed a single-step facile chemical reaction method to form CoSe₂, CoTe₂, and CoS₂ nanostructures. The synthesized CoTe₂ material demonstrated a specific capacity of 370 C g⁻¹ at 1 A g⁻¹ alongside reliable cycling robustness over 10,000 cycles (98%), superior to CoSe₂ and CoS₂ electrodes. An alkaline hybrid asymmetric supercapacitor based on CoTe₂ achieved a 157 F g⁻¹ specific capacitance with 56 Wh kg⁻¹ specific energy and a long cycling life of 97% capacitance retaining over 10,000 cycles. These findings reveal the significant potential of cobalt chalcogenide nanostructures to be applied as prototype electrodes for supercapacitor devices.