Abstract
? 2022 Elsevier B.V.Tin-based materials, which are one of the materials that store Li-ion through an alloying reaction, have been actively studied as anode materials for Li-ion and Na-ion batteries thanks to their high capacity, high electrical conductivity, and low cost. In this paper, we propose a porous Sn2Nb2O7-graphene oxide (GO) composite material that is prepared by a two-step hydrothermal and pyrolysis process. The ternary Sn2Nb2O7 material decomposes into Sn and niobium oxide during the first Li or Na insertion reactions and the niobium oxide acts as a buffer medium to alleviate the volume changes of Sn, as well as a Li/Na storage material through intercalation. Furthermore, a porous structure combined with GO was introduced into the composite, which increased the cycling stability of the electrode. The synthesized material was characterized by X-ray diffraction (XRD), electron microscopy, and X-ray photoelectron spectroscopy. The electrochemical reaction mechanism with Li was thoroughly investigated by ex situ XRD analysis. The electrochemical test results demonstrated that the composite electrode has great potential as both Li-ion and Na-ion anodes because of its high reversible capacity and initial Coulombic efficiency, as well as enhanced cycling and rate performance. The electrochemical performance can be attributed to the incorporation of a porous structure and GO.
NSTL
Elsevier