Microstructure and Electrochemical Properties of Boron-Doped Mesocarbon Microbeads

Abstract

The microstructure and electrochemical properties of pristine and boron‐doped mesocarbon microbeads (MCMBs) were comparatively studied by X‐ray diffraction, field‐emission scanning electron microscopy, Raman spectroscopy, and electrochemical measurements. We examined the correlation between the boron‐doping effect and the electrochemical properties of boron‐doped MCMBs prepared at different heat‐treatment temperatures. It was found that boron doping in MCMBs starts above 1800°C, and then the substitution reaction proceeds with increasing heat‐treatment temperature. The effect of boron doping is to accelerate graphitization of MCMBs for heat‐treatment temperatures in the range from 1800 to 2500°C. Electrochemical lithium intercalation takes place at a higher potential in boron‐doped MCMBs than in undoped MCMBs, presumably because the substitutional boron acts as an electron acceptor in the MCMBs. © 2000 The Electrochemical Society. All rights reserved.