Two-phase separation in a lithiated spinel Li4Ti5O12 crystal as confirmed by electron energy-loss spectroscopy

The coexistence state of two phases (Li4Ti5O12 and lithiated Li7Ti5O12) in spinel lithium titanium oxide (LTO; Li4Ti5O12) is examined using scanning transmission electron microscopy with electron energy-loss spectroscopy (STEM–EELS). A single crystalline LTO specimen is prepared from a TiO2 wafer and is then partially lithiated.