Temperature effects on electrochemical performance of Li4Ti5O12

Li4Ti5O12 (LTO) is one of the most popular Li+-storage anode materials. However, the influences of different operating tempera-tures 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 degrees C, 5 degrees C, 25 degrees C, 45 degrees C, and 60 degrees C. When the operation temperature increases from -10 degrees C to 45 degrees 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 Li+ transport, and higher rate capa-bility. Finally, the maximum unit-cell-volume shrinkage enlarges, resulting in the decay of the cyclic stability. However, when the temperature further rises to 60 degrees C, the rate capacity and cyclic stability rapidly decay due to the severe electrolyte decomposition catalyzed by Ti4+ and the formation of thick solid electrolyte interface (SEI) films.