Controlled Tin Oxide Nanoparticles Encapsulated in N-Doped Carbon Nanofibers for Superior Lithium-Ion Storage

Tin oxide (SnOx) materials suffer from volume expansion and poor electronic conductivity when used as anodes for lithium-ion batteries (LIBs). In this paper, SnOx nanoparticles were controllably encapsulated in N-doped carbon nanofibers (NCNFs) by a facile electrospinning method and subsequent carbonization procedure. The achieved SnOx/NCNFs directly served as free-standing anodes for LIBs. Compared with SnOx prepared on the surface of NCNFs, the encapsulated one exhibits excellent cycling and rate performance, which delivers a specific capacity of 609 mA h g(-1) after 1000 cycles. There may be two reasons for the remarkable lithium storage performance. (1) Carbon nanofibers can effectively suppress the volume expansion of SnOx nanoparticles during electrochemical reactions. (2) The N doped in carbon nanofibers provides accelerated diffusion of lithium ions and electrons.