Nitrogen-doped carbon nanofibers with effectively encapsulated GeO2 nanocrystals for highly reversible lithium storage

Germanium dioxide is a promising high-capacity anode material for Lithium-ion batteries, but it usually exhibits poor cycLing stabiLity due to its Large voLume change during the LithiationideLithiation process. In this paper, homogeneous dispersive Ge02 nanocrystaLs encapsulated by nitrogen-doped carbon nanofibers (GeO2-CNF5) were prepared by a faciLe eLectrospinning technoLogy. The GeO2-CNF anode materiaL exhibited remarkabLe capabiLity at a high rate and excellent cycLing stabiLity (1031 mA h g-1 at 100 mA g-1 after 200 cycLes). The good eLectrochemicaL performance couLd be attributed to the fact that uLtra-uniform CNFs act as a bLocking Layer and a buffer Layer to effectiveLy hoLd GeO2 nanocrystaLs and faciLitate the formation of a stabLe soLid eLectroLyte interphase during Li+ intakeiremovaL. The strategy is a simpLe and effective method which may be extended to other high-capacity anode materiaLs with a Large voLume change and Low eLectricaL conductivity.