High-performance core-shell CoSe2@NiSe2/NC cathode for magnesium-ion batteries

This study focuses on the novel core-shell structured bimetallic selenide CoSe 2 @NiSe 2 /NC., and explores its application in Magnesium-ion batteries (MIBs). Through an efficient electrochemical reaction mechanism, CoSe 2 @NiSe 2 /NC material exhibits excellent performance during charge-discharge cycles, especially in terms of high-rate capability and long cycle stability. At a current density of 0.1 A g −1 , the initial specific capacity of CoSe 2 @NiSe 2 /NC material reaches 380 mAh g −1 , significantly higher than that of CoSe 2 /NC and NiSe 2 /NC materials. Additionally, CoSe 2 @NiSe 2 /NC material demonstrates favorable capacitive and diffusive contributions at different scan rates, with a stable and predictable charge transfer process, reflecting good charge/ion transport capabilities. The outstanding electrochemical performance of the CoSe 2 @NiSe 2 /NC composite is attributed to its unique core-shell architecture, which facilitates efficient charge transport and ion diffusion through interfacial coupling and electronic modulation between the CoSe 2 core and NiSe 2 shell. The material not only effectively buffers volume changes but also suppresses the pulverization and aggregation of the active material, further enhancing the structural stability of the material during long-term charge-discharge processes. Therefore, CoSe 2 @NiSe 2 /NC material provides a new research direction for efficient energy storage systems and holds significant importance for the design of future high-performance battery materials.