Materials Research Bulletin, Vol.48, No.11, 4641-4646, 2013
Effect of freeze-drying and self-ignition process on the microstructural and electrochemical properties of Li4Ti5O12
Crystalline Li4Ti5O12 is synthesized by a method involving the freeze-drying and self-ignition of a gel prepared from titanium isopropoxide, lithium nitrate and hydroxypropylmethylcellulose (HPMC). This synthesis route yields crystalline Li4Ti5O12 particles after calcination at 800 degrees C for 2 h. In an alternative route, addition of ammonium nitrate shifts the self-ignition mode from wave-like propagation to simultaneous. Powders with different microstructures are thereby obtained. Electrochemical characterization shows that the best results for Li+ intercalation/desintercalation are obtained for the powder prepared without ammonium nitrate addition. These results highlight the necessity for a control of the self-ignition mode to obtain adequate properties. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords:Oxides;Sol-gel chemistry;Thermogravimetric analysis (TGA);X-ray diffraction;Electrochemical properties