Refined, in-situ EDXD structural analysis of the Li[Li1/3Ti5/3]O4 electrode under lithium insertion–extraction

Abstract

An in-situ energy dispersive X-ray diffraction (EDXD) analysis has been run on the Li[Li_1/3Ti_5/3]O₄ compound upon Li intercalation–deintercalation process. The results confirm that this process is accompanied by a very small variation of the host lattice parameter, i.e., confined between 1‰ over the entire cycle. This value, which agrees with previous literature information, concurs to demonstrate that Li[Li_1/3Ti_5/3]O₄ may indeed be considered as a zero-strain intercalation compound, this being a characteristic of key technological importance since lattice strains upon cycling are among the main causes of capacity decays in lithium battery electrodes. In addition, this work confirms that EDXD is a quite convenient technique for electrochemical measurements since, allowing in-situ lattice parameter determinations, may lead to a complete evaluation of the intermediate stages of the intercalation process and, possibly, to detect differences among the various cycles.