Black anatase titania enabling ultra high cycling rates for rechargeable lithium batteriesElectronic supplementary information (ESI) available. See DOI: 10.1039/c3ee41960f

• Main Authors: Myung, Seung-Taek, Kikuchi, Masaru, Yoon, Chong Seung, Yashiro, Hitoshi, Kim, Sun-Jae, Sun, Yang-Kook, Scrosati, Bruno
• Format: Journal Article
• Language: English
• Published: 14.08.2013
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/c3ee41960f

In this work we report the synthesis and the characterization of black anatase TiO 2 . We show that this material displays a nanostructured architecture, with an electro-conducting trivalent Ti. The presence of trivalent Ti in this structure narrows the inherent high band gap energy to a semiconductor level, reaching a value as low as 1.8 eV, resulting in the very high electrical conductivity of 8 × 10 −2 S cm −1 . These extraordinary electro-conducting physical properties ensure an ultra fast Li + insertion into and extraction from the host structure of anatase TiO 2 making it a unique, high rate electrode, delivering at a 100 C-rate (20 A g −1 ) a discharge capacity of 127 mA h (g-TiO 2 ) −1 with approximately 86% retention during 100 charge-discharge cycles at 25 °C and approximately 84% retention at −20 °C. Black anatase TiO 2 has a band gap energy as low as 1.8 eV, resulting in a very high electrical conductivity of 8 × 10 −2 S cm −1 . These extraordinary electro-conducting physical properties ensure an ultra fast Li + insertion into and extraction from the host structure of anatase TiO 2 making it a unique, high rate electrode.