In-situ liquid-phase transformation of SnS2/CNTs composite from SnO2/CNTs for high performance lithium-ion battery anode

Abstract SnS2/CNTs composite with hexagonal SnS2 nanosheet growing along carbon nanotube (CNTs) by C-S bonding is synthesized via in-situ sulfuration of prefabricated SnO2/CNTs in the liquid environment. When they are used as Li ion batteries (LIBs) anode materials, the SnS2/CNTs exhibits much better cycling and rate performances than that of SnO2/CNTs. Through in-situ XRD characterization, SnS2/CNTs electrode possesses an additional Li+ intercalation reaction besides conversion and alloying/dealloying reaction in the first cycle. Further analysis by density functional theory (DFT) computations finds that hexagonal SnS2 exhibits lower Li+ adsorption energies and migration barrier than tetragonal structured SnO2, suggesting that Li+ storage and transfer in the SnS2/CNTs electrode is much easier and faster than SnO2/CNTs. As a consequence, SnS2/CNTs composite is more favorable for Li+ storage and is a promising anode material for LIBs.