Nitrogen-doped carbon flakes inlaid with bimetallic selenide for high-performance sodium ion storage

A simple preparation method of the anode is designed for sodium ion battery. The bimetallic selenide (CoSe₂/ZnSe) and nitrogen-doped carbon composite materials are obtained by selenization and carbonization of the metal organic framework precursors, and applied to high-performance sodium ion storage. The ingenious nanostructure is shown in that CoSe₂ and ZnSe nanoparticles are evenly distributed on the fusiform flake carbon skeleton. This synergy can improve the capacity and conductivity, and inhibit the volume expansion during the cycle. For electrochemical performance analysis, the prepared 1:1-CoSe₂/ZnSe@NCC electrode shows a high discharge specific capacity of 621.5 mA h g^-1 at 0.1 A g^-1 after 100 cycles (coulomb efficiency close to 100%, capacity retention reaches ~ 90%), and has advantages over other electrodes in terms of rate performance and reaction kinetics. The excellent electrochemical performance confirms the successful development of a high performance electrode for sodium ion storage by this strategy.