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Lookup NU author(s): Professor Ulrich Stimming
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).
We report that an ultrafast kinetics of reversible metal-ion insertion can be realized in anatase titanium dioxide (TiO2). Niobium ions (Nb5+ ) were carefully chosen to dope and drive anatase TiO2 into very thin nanosheets standing perpendicularly onto transparent conductive electrode (TCE) and simultaneously construct TiO2 with an ion-conducting surface together with expanded ion diffusion channels, which enabled ultrafast metal ions to diffuse across the electrolyte/solid interface and into the bulk of TiO2. To demonstrate the superior metal-ion insertion rate, the electrochromic features induced by ion intercalation were examined, which exhibited the best color switching speed of 4.82 s for coloration and 0.91 s for bleaching among all reported nanosized TiO2 devices. When performed as the anode for the secondary battery, the modified TiO2 was capable to deliver a highly reversible capacity of 61.2 mAh/g at an ultrahigh specific current rate of 60 degrees C (10.2 A/g). This fast metal-ion insertion behavior was systematically investigated by the well-controlled electrochemical approaches, which quantitatively revealed both the enhanced surface kinetics and bulk ion diffusion rate. Our study could provide a facile methodology to modulate the ion diffusion kinetics for metal oxides.
Author(s): Wang HY, Chen HY, Hsu YY, Stimming U, Chen HM, Liu B
Publication type: Article
Publication status: Published
Journal: ACS Applied Materials & Interfaces
Print publication date: 26/10/2016
Online publication date: 11/10/2016
Acceptance date: 11/10/2016
Date deposited: 14/12/2016
ISSN (print): 1944-8244
ISSN (electronic): 1944-8252
Publisher: American Chemical Society
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