However, most of the peaks from potential SEI components (like Li2CO3 and Li2O) are located from 1200 to 1500 cm -1 , which overlap the D and G bands . Therefore, surface chemical composition of Si-SiOx@Cs anodes after Li deposition was further investigated by XPS analysis for a better understanding of the advantage of introduced CNT skeleton. The XPS spectra were collected when lithium is fully intercalated into the anodes under 0.1 A•g -1 , as illustrated in Fig. . For comparison, XPS analysis of anodes before cycling was also conducted as shown in Fig. . The XPS spectra before cycling show the Si 2s and Si 2p peaks from SiOx@C and Si nanoparticles, while Si related peaks disappear after full lithiation, indicating that the outer SEI layer covers the anode surface and has enough thickness to stop the Si signal . Also, both the Si-SiOx@C and Si-SiOx@C-1.25 show the existence of F, C, O and Li elements, verifying the formation of SEI layer. From the high-resolution C 1s and O 1s spectra (Fig. , Fig. ), the C-O is detected at 286.3 eV and 531.1 eV while the C=O is detected at 286.9