Electrochemical and spectroscopic characterization of lithium titanate spinel Li4Ti5O12

Herein we describe electrochemical and spectroscopic properties of lithium titanate spinel as well as an easy method based on colorimetry to determine the lithium content of electrodes containing lithium titanate spinel as active material. Raman microspectrometry measurements have been performed to follow lithium insertion into and extraction from the active material, respectively. The Raman signals display a pronounced fading of intensity already at low levels of lithium intercalation and disappear at a SOC higher than ∼10%. However, the colorimetric method can be used up to a SOC of 50%.