Photo-electrochemical Lithium Insertion Characteristics of Carbon Nanotubes Modified with SrTiO3 Photocatalyst

Perovskite-type SrTiO3 nanoparticles were synthesized by direct hydrolysis-precipitation method and were employed to modify the surface of the carbon nanotubes to form a SrTiO3/CNTs composite. The photo-electrochemical lithium insertion characteristics of the SrTiO3/CNTs composite under xenon light irradiation were investigated. The results show that the light irradiation has little influence on the specific capacity of the CNTs electrode. However, for the SrTiO3/CNTs electrode irradiated by light, the lithium insertion capacity reaches about 251 mAh/g, much higher than that without light irradiation (170 mAh/g). Cyclic voltammetry test reveals that the light irradiation can remarkably increase the reaction currents of lithium insertion and extraction. This may be attributed to the photo-excited intercalation of Li-ions into the CNTs by the SrTiO3 photocatalyst when irradiated by light.