Insight into the Formation/Decomposition of Solid Electrolyte Interphase Films and Effects on the Electrochemical Properties of Sn/Graphene Anodes

Abstract

A robust solid electrolyte interphase film formed on the anode is of importance for the electrochemical performances of a lithium-ion battery. In this work, the formation and decomposition of the solid electrolyte interphase film on the Sn/graphene anode are studied through scanning electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy measurements, which are performed systematically on the anode before and after the lithiation and the lithiation/delithiation cycling. It is demonstrated that at the first few lithiation/delithiation cycles, the solid electrolyte interphase film is formed and decomposed accordingly. However, with lithiation/delithiation cycling progressing, the solid electrolyte interphase film gets stable and stable, and a robust solid electrolyte interphase film is formed after 10 lithiation/delithiation cycles, which is different from that on a bare Sn anode. The hyperfine X-ray photoelectron spectroscopy data show that the solid electrolyte interphase film should be initiated both on graphene and Sn, but the one formed on the graphene component is more stable than that on the Sn, which is enlarged with lithiation/delithiation progressing and covers the whole Sn/graphene anode after about 10 lithiation/delithiation cycles, forming a robust solid electrolyte interphase film.