Carbon‐Shielded Selenium‐Rich Trimetallic Selenides as Advanced Electrode Material for Durable Li‐Ion Batteries and Supercapacitors

Abstract In order to achieve a sustainable future, researchers must continue to research improved electrode materials. Considering the high electronic conductivity, versatile redox activity, and enhanced energy storage performance, nanostructures have been employed as a novel electrode material for high‐performance lithium‐ion batteries (LIBs) and supercapacitors. Herein, carbon‐coated selenium‐rich trimetallic selenide (Cu 2 NiSnSe 4 @C) nanoparticles (NPs) as an efficient electrode material in energy storage devices are prepared. The prepared core‐shell Cu 2 NiSnSe 4 @C NPs electrode is employed as an anode material for LIBs, which demonstrated a high reversible specific capacity of 988.46 mA h g −1 over 100 cycles at 0.1 A g −1 with good rate capability. Additionally, the core‐shell Cu 2 NiSnSe 4 @C NPs electrode exhibited an outstanding capacity of 202.5 mA h g −1 at 5 A g −1 even after 10 000 cycles. Exploiting the synergistic characteristics, the core‐shell Cu 2 NiSnSe 4 @C NPs material is also investigated as a battery‐type electrode for hybrid supercapacitors. The assembled hybrid supercapacitor with Cu 2 NiSnSe 4 @C NPs and activated carbon showed excellent rate capability including high power (5597.77 W kg −1 ) and energy (64.26 Wh kg −1 ) densities. Considering the simple synthesis and enhanced energy storage properties, carbon‐coated selenium‐rich trimetallic selenide can be used as a durable electrode material for practical energy storage devices.