A Study of the Composition and Structure of a Solid Electrolyte Interface (SEI) Formed on the Surface of Electrode Material Based on SnOx/Sn@MWCNT Nanocomposite

Abstract

In the process of the performed studies, new information has been obtained about the composition and structure of the solid electrolyte interface (SEI) formed on the surface of electrodes based on the initial composite SnOx@MWCNT (tin oxide/multiwall carbon nanotubes) and the SnOx/Sn@MWCNT composite formed by irradiation using a pulsed ion beam of nanosecond duration. It has been shown that, after long сycling of electrode based on an irradiated composite (SnOx/Sn@MWCNT), the tin concentration remained approximately at the same level. This result indicated high interphase adhesion of the metal–oxide component to the surface of MWCNTs in the irradiated composite. Using X-ray photoelectron spectroscopy methods, it has been established that the SEI layer formed under these conditions consisted predominantly of lithium carbonate and oxide and organic compounds comprising products of interaction of solvents (ethylene carbonate and dimethyl carbonate) of the electrolyte with the electrode surface. It has been found that the electrode based on the irradiated composite demonstrates the best electrochemical characteristics as a material for the electrodes of lithium-ion batteries.