SnSe₂ Nanoparticles Chemically Embedded in a Carbon Shell for High-Rate Sodium-Ion Storage

The development of advanced anode materials is crucial to enhance the performance of sodium-ion batteries (SIBs). In this study, SnSe₂ nanoparticles chemically embedded in a carbon shell (SnSe₂@C) were fabricated from Sn-organic frameworks and evaluated as an anode material for SIBs. The structural characterization demonstrated that there existed C-Sn chemical bonds between the SnSe₂ nanoparticles and carbon shell, which could strongly anchor SnSe₂ nanoparticles to the carbon shell. Such a structure can not only facilitate charge transfer but also ensure the structural stability of the SnSe₂@C electrode. In addition, the carbon shell also helped in the dispersion of SnSe₂ nanoparticles, thus offering more redox-active sites for Na⁺ storage. The as-prepared SnSe₂@C nanocomposite could deliver good cycling stability and a superior rate capability of 324 mA h g^-1 at 2 A g^-1 for SIBs.