Open AccessDegradation Dynamics for Electrochromic WO3 Films under Extended Charge Insertion and Extraction: Unveiling Physicochemical Mechanisms
Author(s) -
RuiTao Wen,
Sara Malmgren,
Claes G. Granqvist,
Gunnar A. Niklasson
Publication year - 2017
Publication title -
acs applied materials and interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.535
H-Index - 228
eISSN - 1944-8252
pISSN - 1944-8244
DOI - 10.1021/acsami.7b01324
Subject(s) - electrochromism , materials science , dielectric spectroscopy , electrolyte , diffusion , chemical physics , transmittance , electrochromic devices , cyclic voltammetry , intercalation (chemistry) , electrode , degradation (telecommunications) , analytical chemistry (journal) , optoelectronics , chemical engineering , electrochemistry , inorganic chemistry , electronic engineering , thermodynamics , chemistry , organic chemistry , physics , engineering
Degradation of electrochromic thin films under extended charge insertion and extraction is a technically important phenomenon for which no in-depth understanding is currently on hand. Here, we report on an explorative study of sputter-deposited WO 3 films in a Li-ion-conducting electrolyte by use of cyclic voltammetry, in situ optical transmittance, and impedance spectroscopy. A cycling-dependent decrease of the charge capacity could be accurately modeled by a power-law function, and impedance spectroscopy gave evidence for anomalous diffusion as well as a higher charge-transfer resistance during deintercalation than during intercalation. Thus, a consistent conceptual picture emerged for the degradation dynamics; it includes the growth of an interfacial barrier layer and also embraces anomalous diffusion coupled with dispersive power-law chemical kinetics.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom