The fine structure and elemental composition of Si-SiOx@Cs were further characterized by TEM and STEM-EDS. Fig. shows the TEM image of Si-SiOx@C- This could also be verified by XRD (Fig. ), in which the broad peak from 15 o to 30 o are ascribed to amorphous carbon and silicon oxide and the series of sharp peaks are from crystalline silicon . In Fig. , the broad peaks from 101 to 106 eV could be fitted with Si 2+ (103.1eV) and Si 3+ (103.7 eV) . The typical peak of Si-O bond at around 532 eV is also confirmed in the O 1s spectra (Fig. ). For the Si 2p spectrum of Si-SiOx@C, the normalized percentages of Si 2+ and Si 3+ are 48.1% and 51.99%, respectively. Therefore, the estimated Si valence state is 3.56. Similarly, the Si valence states of Si-SiOx@C-1.25, Si-SiOx@C-2.5 and Si-SiOx@C-5 are 2.14, 2.14 and 2.28, respectively (Table ). The valence differences between samples with and without CNTs might be caused by that the existence of CNTs having an effect on the formation of SiOx@C polymer precursors. The ratios of D and G bands of Si-SiOx@Cs in the Raman spectra are 0.895, 0.854, 0.872 and 0.897, respectively (Fig. ), indicating the formation of a carbon framework during the carbonization process.