2003 Volume 71 Issue 12 Pages 1132-1135
In situ atomic force microscope observation coupled with cyclic voltammetry of the basal plane of highly oriented pyrolytic graphite was carried out at room and elevated temperatures to investigate the surface film formation on graphite negative electrode in lithium-ion cells. The observation revealed that solvent decomposition and precipitate layer formation were enhanced at elevated temperatures. The thickness of the resulting precipitate layer on the surface increased with an increase in temperature. It was concluded that enhanced solvent decomposition and the growth of the surface film are the major reasons for the increase in irreversible capacity at elevated temperatures.