Controlled Synthesis of (Ni, Co) Bimetallic Selenide Composites Supported on Carbon Cloth and Their Application in Supercapacitors

Transition metal selenides have attracted much attention as electrode materials for supercapacitors, and reasonable morphology control strategies can effectively improve their actual energy storage capacity and performance. Here, we synthesized (Ni,Co)Se₂ nanosheet arrays with a nanopetal and nanoagaric morphology on a flexible carbon cloth by simply adjusting the solvothermal reaction conditions. It was found that compared with the nanoagaric (Ni,Co)Se₂ nanosheet array, the nanopetal (Ni,Co)Se₂ nanosheet array has a more highly ordered structure and larger specific surface area, which can provide a large number of reaction sites and promote the transfer of electrons and ions, which effectively enhances the performance of the supercapacitor. The power density of asymmetric supercapacitors with the nanopetal (Ni,Co)Se₂@CC as the positive electrode is 250.0 W kg^–1, while the maximum energy density can reach 75.3 Wh kg^–1, demonstrating superior performance compared to other similar materials. This work provides a new method for the design of electrode material morphology for high performance.