Evaluation of graphite materials as anodes for lithium-ion batteries

The electrochemical performance of a series of natural and synthetic graphite powders was investigated for their viability as anode materials in lithium-ion batteries. The variation of the charge and discharge capacities can be qualitatively correlated to their structural and morphological differences. The specially treated natural graphite samples show excellent capacity and relatively small irreversible capacity losses. A noticeable percentage of the rhombohedral phase was observed in the natural graphite samples. The good electrochemical performance of these graphite powders may be attributed to the combination of low surface area and absence of exfoliation due to the presence of the rhombohedral phase and defects in the grain boundaries. Graphitized cokes generally exhibited larger irreversible capacity loss, and mesophase carbons produced relatively low reversible capacity. (C) 2000 The Electrochemical Society. S0013-4651(00)01-045-4. All rights reserved.