Effect of coating thickness of Al-doped Li4Ti5O12 (LTO) on the electrochemical performance of half cell battery

Effect of coating thickness of Al-doped Li4Ti5O12 (LTO) sheet on the electrochemical performance of battery cells is reported. A 0.025 mol Al-doped LTO powder was synthesized by solid state reaction method, for the anode sheet was made by the doctor blade method. The sheet manufacturing was carried out by varying the coating thickness from 100, 200, 300 and 400 μm to determine the effect on the electrochemical performance of the battery cell. The analysis of phase was conducted by X-ray diffraction (XRD); for electrochemical performances were conducted by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and charge discharge (CD) method. XRD analysis showed that there are two phases formed, i.e. LTO and rutile phases (TiO2) of 75.6% and 24.4%, respectively. EIS results showed that the thicker the coating layer, the conductivity of the sample become slower. Furthermore, the results indicate that the sample with thickness of 100, 200 and 300μm indicated sharp redox peak, and 400 μm showed wide redox peaks. The specific capacity and specific power of the half cell battery decreases with the increasing of coating thickness. The best cell capacity is obtained by sample with 100 μm thickness with specific discharge capacity of 134.3 mAh/g.