Oxides overlayer confined Ni3Sn2 alloy enable enhanced lithium storage performance

Sn-based materials have been expected as promising anodes in lithium-ion batteries (LIBs) owing to the high theoretical specific capacity (over 2 times of graphite), low price and environmentally friendliness. However, the development of Sn-based materials is always restricted by the poor cyclic and rate performance caused by low conductivity. To address these problems, NiO&SnO2 (NiSnOx) surface oxides overlayer confined Ni3Sn2 particles supported on carbon nanotubes (Ni3Sn2@NiSnOx/CNT) are fabricated via a simple impregnation-reduction-oxidation method. Noteworthy, such hierarchical composites feature several merits including: (i) the oxides overlayer in-situ generates a nanometric matrix of Li2O, which separates the electrolyte from the active anodes, and accelerate lithium extraction from the anode material; (ii) the Ni matrix provides sufficient space to adjust the volume change during lithiation/delithiation processes; (iii) the CNT provides interconnected electronic conductive networks. As LIBs anodes, Ni3Sn2@NiSnOx/CNT exhibits higher specific capacitance values (1521 niA h g(-1)), superior rate capability (46% capacity remain at 50 times current amplification) and better cyclic stability (1041 mA h g(-1) after 1000 cycles). Relying on the excellent electrochemical performance, the hierarchical Ni3Sn2@NiSnOx/CNT nanocomposites are considered as a promising anode material for LIBs.