Effect of mechanical milling of graphite powder on lithium intercalation properties

Mechanically milled graphite powder for different durations was used as anode in lithium-ion battery. Reversible capacity and coulombic efficiency of the milled and pristine powders were measured. It was found that the controlled milling increases the reversible capacity and coulombic efficiency of the first cycle from 356 to 368 Ah kg(-1) and from 83 to 86%, respectively. The milled powder was analyzed for particle size distribution, bulk and surface structure by particle size analyzer, powder X-ray diffractometer, and Raman spectroscopy and electron microscope, respectively, to understand the effect of mechanical milling of graphite powder on its physical properties. The mild milling lead to aggregation of graphite particles, that had significant influences on the electrode performance. Graphite-tin dioxide composite electrode has also been prepared by the mechanical milling and the preliminary result indicates that the mechanical milling would be used to prepare the high capacity composite electrodes. (C) 2001 Elsevier Science B.V. All rights reserved.