Abstract

A novel graphite material for lithium ion batteries was prepared by encapsulation of an ionic conductive polymer on the surface of natural graphite particles via radiation-initiated polymerization. The graphite obtained shows great improvement in electrochemical performance such as initial coulombic efficiency and cycleability compared with the original natural graphite. Raman spectroscopy indicates that the structural stability of the graphite surface is enhanced due to the fact that encapsulated polymers can depress the exfoliation of graphite layers caused by co-intercalation of solvent molecules. The solid electrolyte interface (SEI) film formed on the encapsulated graphite electrode retains a stable morphology during repeated cycling, and thus avoids an increase in the electrode's impedance.