Oxygen deficient, carbon coated self-organized TiO2 nanotubes as anode material for Li-ion intercalationElectronic supplementary information (ESI) available. See DOI: 10.1039/c5ta03621f

• Main Authors: Brumbarov, J, Vivek, J. P, Leonardi, S, Valero-Vidal, C, Portenkirchner, E, Kunze-Liebhäuser, J
• Format: Journal Article
• Language: English
• Published: 04.08.2015
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c5ta03621f

Since several years, research for high capacity anode materials in Li-ion batteries is addressed to titanium dioxide (TiO 2 ), which offers important advantages in terms of cost effectiveness, safety and environmental compatibility. This work reports on the lithiation and delithiation characteristics of anodically grown, self-organized TiO 2 nanotubes annealed in Ar (TiO 2− x ) and Ar/C 2 H 2 (TiO 2− x -C). The systems are used as model composite electrodes for the anode in Li-ion batteries. Anatase TiO 2− x -C nanotubes demonstrate a superior Li storage capacity as high as 320(±68) mA h g −1 (Li 0.96 TiO 2 ) compared to 180(±38) mA h g −1 (Li 0.54 TiO 2 ) for TiO 2− x . This is comparable to the highest reported capacities for TiO 2 nanotubes to date. The double layer capacities are estimated from cyclic voltammetry measurements to 85 μF cm − ² for TiO 2− x and 20 μF cm − ² for TiO 2− x -C nanotubes respectively. Additionally, electrochemical impedance spectroscopy reveals smaller charge transfer resistances for TiO 2− x -C nanotubes at the solid/liquid interface which improves the transfer of Li + -ions from the electrolyte into the electrode. Anatase TiO 2− x -C nanotubes demonstrate a superior Li storage capacity as high as 320(±68) mA h g −1 compared to 180(±38) mA h g −1 for TiO 2− x .