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.