Comparative study of composites Li4Ti5O12/Li2TiO3 prepared by solid state and hydrothermal methods

Abstract

The composites LTO/Li2TiO3 with different Li2TiO3 phase content were synthesized by solid-state and hydrothermal methods and their phase composition and electrochemical properties were investigated. The solid-state method enabled obtaining a two-phase composites β-Li2TiO3/LTO with a given content of the β-Li2TiO3. In particular, the composite was obtained containing 17.79 mol % β-Li2TiO3 phase in the composite with the grain size of the components of 500.1 ± 20.8 nm and 154 ± 18 nm, for LTO and β-Li2TiO3, respectively. Using hydrothermal method from anatase and LiOH as precursors, only composites with high concentration of β-Li2TiO3 phase of 56.37 mol % was obtained. In this composite grain size values were 73.1 ± 7.4 nm and 67.7 ± 11.2 nm for LTO and β-Li2TiO3 phases, respectively. Unfortunately, using hydrothermal method we could not diminish the concentration of β-Li2TiO3 phase in the composites. Analysis of the charge–discharge curves showed that the discharge capacity of SS-LTC sample, nearly 175 mA·h, is close to the theoretical value for LTO, whereas the discharge capacity of HM-LTC sample, 75 mA·h, is low that is caused by the presence of a high content of electrochemically inert β-Li2TiO3 phase in the electrode material.