Effect of mechanical milling of graphite powder on lithium intercalation properties

Mechanically milled graphite powder for different durations was used as ano de in lithium-ion battery. Reversible capacity and coulombic efficiency of the milled and pristine powders were measured. It was found that the contro lled 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 su rface structure by particle size analyzer, powder X-ray diffractometer, and Raman spectroscopy and electron microscope, respectively, to understand th e effect of mechanical milling of graphite powder on its physical propertie s. The mild milling lead to aggregation of graphite particles, that had sig nificant influences on the electrode performance. Graphite-tin dioxide comp osite electrode has also been prepared by the mechanical milling and the pr eliminary result indicates that the mechanical milling would be used to pre pare the high capacity composite electrodes. (C) 2001 Elsevier Science B.V. All rights reserved.