The formation of a solid electrolyte interface (SEI) at the surface of a SWNT electrode was investigated by SEM, TEM, XRD, and Raman spectroscopy. These analyses were carried out at different charge-discharge cycles, showing the cycle dependent character of the SEI formation. The changes in chemical species of SEI with increased number of cycles have been examined. This study shows by XRD, that inorganic species of SEI are LiF and Li2CO3, and that the SEI formation depends on the number of discharge-charge cycles.
