Heterostructural Snse/Snte Ultrasmall Nanoparticles Embedded in Nitrogen-Doped Carbon Nanofibers (Snse/SnteN-Cnfs) for High Performance Sodium-Ion Batteries

Heterostructural ultrasmall particles are attractive for batteries due to their rapid charge transfer kinetics. A novel material with SnSe/SnTe heterostructural nanoparticles embedded in N-doped carbon nsnofibers (SnSe/SnTe@N-CNFs) was firstly synthesized by using a facile selenization/tellurization process of Sn 2+ to SnSe/SnTe heterostructure and a pyrolysis of electrospun PAN-P123 fibers to porous N-CNFs. SnSe/SnTe can offer high Na-storage capacity based on the Na-rich alloying/de-alloying reactions (Na 3.75 Sn, Na 2 Se, and Na 2 Te). Meanwhile, the porous N-CNFs conductive matrix endows the hybrid with rapid ion/charge transfer kinetics, efficient buffer space, and strong fibers skeleton for severe volume variation. As a result, the SnSe/SnTe@N-CNFs nanofibers exhibited large Na-storage capacity (480 mAh g −1 at 0.1 A g −1 ), remarkable rate capability (250 mAh g −1 even at 2 A g −1 ) with highly practical initial Coulombic efficiency (80%). This study provides not only a facile method for designing Na-rich alloying electrode materials but also a strategy of offering excellent electrochemical performances by using heterostructural nanoparticles embedding in porous carbon fibers for SIBs