Improving the properties of Li4Ti5O12 - a promising anode material for lithium-ion batteries

Abstract

Two materials with the stoichiometric composition Li3.85Ni0.15Ti5O12 and Li3.80Cu0.05Ni0.15Ti5O12 were obtained by solid-state reaction using lithium carbonate Li2CO3, titanium oxide TiO2, nickel oxide NiO and copper oxide CuO. The materials were characterized in terms of phase composition, crystal structure as well as cycle performance. Phase composition and crystal structure parameters were determined using X-ray Panalytical Empyrean XRD diffractometer in the range of 10-110° with CuKa radiation. The results were analyzed using Rietveld refinement which was then implemented in the GSAS computer software. The electrochemical properties of the samples were measured by galvanostatic charge/discharge cycles at different rates over a voltage range of 1.0-2.5 V and 0.2-2.5 V. Cyclic voltammetry measurements were also carried out. It was proved that the addition of both Ni and Cu results in high specific capacity of LTO especially at high current rates (2C and 5C). The sample Li3.80Cu0.05Ni0.15Ti5O12 delivers superior capacity above 200 mAh·g -1 when discharged to 0.2 V.