Mesophase Pitch Carbon Coated with Phenolic Resin for the Anode of Lithium-Ion Batteries

Abstract

A procedure was developed to prepare surface-modified mesophase pitch carbon to increase the charge−discharge capacity and cycleability of carbon electrodes for lithium-ion batteriers (LIBs). According to Raman spectra and X-ray diffraction (XRD) patterns, the mesophase pitch carbon-coated phenolic resin consists of a non-graphitic carbon and a graphitic carbon. After high-temperature treatment, GMP40 shows the highest first charge and discharge capacities of 426 and 322 mAh g−1, respectively, while mesophase pitch carbon shows the first charge and discharge capacities of 237 and 206 mAh g−1, respectively. The modified carbon demonstrates higher initial charge−discharge capacity and cycleability than mesophase pitch carbon because the coating layer has improved compatibility with electrolytes and the outer turbostratic structure provided more sites for Li+. The differences in capacity and cycleability between the mesophase pitch carbon and modified carbons are discussed.