title: Low temperature hydrogen reduction of high surface area anatase and anatase/β-TiO₂ for high-charging-rate batteries.
abstract: There are several strategies to improve the electrochemical performance of TiO2 as negative electrode material for Li-ion batteries. Introducing oxygen vacancies through hydrogen reduction leads to an enhancement in electrical conductivity. However, this strategy does not improve the low lithium-ion mobility. Herein, we show that by decreasing the temperature of hydrogen annealing the improved lithium-ion mobility of high-surface-area TiO2 and β-TiO2 can be combined with the enhanced electrical conductivity of oxygen deficiencies. Annealing at only 275-300 °C in pure hydrogen atmosphere successfully creates oxygen vacancies in TiO2, as confirmed by UV/Vis spectroscopy, whereas the temperature is low enough to maintain a high specific surface area and prevent β-to-anatase phase transformation. The hydrogen reduction of high-surface-area anatase or anatase/β-TiO2 at these temperatures leads to improvements in the performance, achieving charge capacities of 142 or 152 mAh g(-1) at 10C, respectively.
authors.affiliation: Analytische Chemie-Elektroanalytik & Sensorik, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany). edgar.ventosa@rub.de.
authors.forename: Edgar
authors.initials: E
authors.lastname: Ventosa
authors.forename: Anna
authors.initials: A
authors.lastname: Tymoczko
authors.forename: Kunpeng
authors.initials: K
authors.lastname: Xie
authors.forename: Wei
authors.initials: W
authors.lastname: Xia
authors.forename: Martin
authors.initials: M
authors.lastname: Muhler
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schuhmann
mesh_terms: D011211:Electric Power Supplies; D004563:Electrochemistry; D004566:Electrodes; D006859:Hydrogen / Q000737:chemistry*; D010084:Oxidation-Reduction; D013499:Surface Properties; D013696:Temperature; D014025:Titanium / Q000737:chemistry*
chemical_list: C009495:titanium dioxide; D006859:Hydrogen; D014025:Titanium
keywords: batteries; lithium; oxygen deficiency; surface area; titania