(211g) Hollow ZnSe/SnSe2 Cubes with Urchin Spines-like Rods Incorporated Carbon Nanofibers As Anodes for Sodium-Ion Batteries

The exploration of Sn-based anode materials has gained considerable momentum owing to their remarkable theoretical capacity and energy density. Among them, alloy-based materials provide a promising route for improved stability and enhanced reaction kinetics during a charging/discharging process. In addition, combining metal compounds with carbon matrix represents a common and effective strategy to further enhance structural stability and integrity for practical application of batteries. Herein, a unique three-dimensional (3D) carbon nanofibers (CNFs) scaffold comprising of hollow ZnSe/SnSe₂ cubes with urchin-like spines was rationally designed by hydrothermal, electrospinning and carbonization processes, as a free-standing anode, resulting in superior electrochemical performance. Selenides are preferentially chosen over other chalcogenides, attributable to their balanced characteristics in electrical conductivity for electron transfer, interlayer spacing for Na ion transfer, and theoretical capacity. Hollow cavity in ZnSe/SnSe₂ cubes increases specific surface area, exposes more accessing sites in electrolyte for reactions, and compensates volume expansion. Notably, heterostructures of ZnSe/SnSe₂ can facilitate fast ion/electron transfer and kinetics of reactions in batteries, through built-in electric field in the formed interfaces between ZnSe and SnSe₂ nanoparticles. To ensure the overall integrity of anode, carbon nanofiber matrices serve as another reliable protective shells and excellent conductive skeletons, preventing selenides from direct contact with electrolyte and enhancing conductivity of whole structure. This innovative approach combines the merits of various components for great integrality of electrodes and ultimately broadens the routes for developing high-performance Sn-based anode materials in SIBs.