In Situ Raman Observation of Zinc-Induced Structural Dynamics and Charge Transfer of a Layered V2O5

In situ techniques to disclose electrochemical and interfacial behavior between electrode and electrolyte in a quantitative manner are in high demand in numerous fields including electrochromism, energy storage as well as basic science research. This work demonstrates a self-made in situ Raman spectra technique coordinating with an electrochemical workstation and its utility for zinc-induced structural dynamics and charge transfer of a layered V 2 O 5 . The increase or decrease of Raman activity modes of V–O 3 , O 1 –V–O 2 and O 1 –V–O 3 at applied low or high voltages is probably due to the presence of “free pathway” within layers. An interpretation is proposed where the two stages of bidirectional reversibility of Zn 2+ intercalation and deintercalation from “free pathway” and V 2 O 5 matrix occur via an electrochemical process, followed by Zn 2+ continuous aggregation, fusion and possible transformation to Zn x V 2 O 5 . A distinct difference between Li + -based and Zn 2+ -based electrolytes is that the Raman active modes between V atom and apical oxygen are almost not enhanced or weakened for V 2 O 5 in Zn 2+ -based electrolyte, most likely due to the greater Coulomb force of Zn 2+ on V 2 O 5 matrix than that of Li + . These observations have implications for understanding the performance and stability of electrochromic devices.