Abstract
A combination of operando Electrochemical Quartz Microbalance (EQCM) and Electrochemical Dilatometer techniques (ECD) have been used to study lithium intercalation into TiS2. Confirmation of two distinct Li-ion intercalation regions was achieved, showing distinct diffusion kinetics and interlayer space parameters. Starting from Li0TiS2, a first lithiation zone exhibits diffusion limited (battery-like) behavior, which is associated with a significant electrode volume expansion. Conversely, once a maximum interlayer distance is attained, subsequent lithiation results in nondiffusion limited (capacitive-like) behavior, with no further evolution of the volume of the material. Additionally, EQCM motional resistance analysis shows that the TiS2 under consideration undergoes a reversible transformation, while keeping its viscoelastic properties constant. This study sheds light on the mass transport and deformation analysis of a model material such as TiS2. Finally, a direct correlation between two operando techniques such as ECD and EQCM to explain charge storage mechanisms is for the first time reported.