In Situ Raman Observation of Dynamically Structural Transformation Induced by Electrochemical Lithium Intercalation and Deintercalation from Multi‐Electrochromic V₂O₅ Thin Films

Abstract

Understanding the dynamic nature of electrochemical interface induced by ion transfer is of great significance. Herein, in situ Raman spectroscopy combined with electrochemistry has been developed to real‐time monitor the transfer of lithium ions at electrode‐electrolyte interface and reveal the associated structure and performance variation of the vanadium pentoxide (V2O5) thin films on the indium tin oxide/silver/aluminum zinc oxide/poly(ethylene terephthalate) (ITO/Ag/AZO/PET) substrates. It is demonstrated that the Raman active/silent states of the vibrational modes of VO, V3O, and VO bonds, as well as the transformation of the V2O5 thin films from V2O5 to lithium vanadate (LixV2O5), can be reversibly changed with reversible extraction/insertion of lithium ions. In situ UV‐vis spectroscopy in combination with in situ Raman analysis is applied to show that the reversible evolutions involving V2O5/LixV2O5 and VO bonding characteristic contribute to the multi‐color electrochromic characteristic of the V2O5 thin films enabling a superior optical modulation of up to 75.41%. This experimental approach establishes a significative guideline for the more elaborate research on the dynamic nature of electrochemical interface.

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

“…Throughout a full circle, the shape of this peak becomes sharper, which may be due to the squeeze of the inserted ion and electrons causing the rotation of the V atom and thus affecting its ordering. 32 Comparing with our previous work 23 on in situ Raman spectrum of Li + -induced V 2 O 5 •H 2 O, the peaks at 1027 cm −1 and 976 cm −1 change in a very slight extent (see Fig. S5 in supporting information), which is most likely due to the greater Coulombic force between Zn 2+ and the V 2 O 5 skeleton.…”

“…In our previous work, as an alternative to ex situ Raman, an unconventional self-manufactured electrochemical in situ Raman technique was used to investigate structure variation of the nanocrystal-in-glass and layered V 2 O 5 thin films in Li + -based electrolyte. 23 Here, we develop this powerful and sensitive in situ spectroscopic Raman measurement system as presented in Fig. 1a to monitor the local structure changes on the electrode-electrolyte interface of a layered V 2 O 5 and Zn 2+ -based electrolyte during the redox reaction.…”