Preparation and characterization of spinel Li4Ti5O12 anode material from industrial titanyl sulfate solution

Metatitanic acid was synthesized from industrial titanyl sulfate solution via controlling pH during hydrolyzing process. Inductively coupled plasma (ICP) analysis confirmed that a little Fe, Mg and Ca were deposited into precursor TiO2·H2O. Spinel Li4Ti5O12 was prepared by sintering amorphous mixture at 800 °C for 16 h. The amorphous mixture was activated by ball-milling at room temperature, using the as-prepared TiO2·H2O and Li2CO3 as raw materials. The sample was characterized by X-ray diffractometry, scanning electron microscopy and electrochemical charge and discharge test. The results show that spinel Li4Ti5O12 is obtained, but it contains a few rutile TiO2 impurities. The sample has fine particles with size of around 50 nm and homogenous size distribution. At room temperature, the initial reversible specific capacity of the sample is 136.9, 128.0, 119.2 and 96.3 mA·h/g at 0.1C, 1C, 2C and 5C, respectively, and the sample shows excellent cycling performance.