Temperature effects on electrochemical performance of Li4Ti5O12

Abstract

Li4Ti5O12(LTO) is one of the most popular [Formula: see text]-storage anode materials. However, the influences of different operating temperatures on the electrochemical performance of LTO and the underlying mechanisms are still unclear. Herein, we systematically investigate its temperature-dependent electrochemical performance, electrochemical kinetics, and crystal-structural evolution at −10[Formula: see text]C, [Formula: see text]C, [Formula: see text]C, [Formula: see text]C, and [Formula: see text]C. When the operation temperature increases from −10[Formula: see text]C to [Formula: see text]C, more intensive electrolyte decomposition increases the irreversible capacity in the first cycle, which decreases the initial Coulombic efficiency. Meanwhile, the electrochemical kinetics becomes faster, leading to reduced electrode polarization, faster [Formula: see text]Transport, and higher rate capability. Finally, the maximum unit-cell-volume shrinkage enlarges, resulting in the decay of the cyclic stability. However, when the temperature further rises to 60°C, the rate capacity and cyclic stability rapidly decay due to the severe electrolyte decomposition catalyzed by [Formula: see text] and the formation of thick solid electrolyte interface (SEI) films.