Insights into the Li Diffusion Dynamics and Nanostructuring of H2Ti12O25 To Enhance Its Li Storage Performance

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• 作者：Soomin Park ; Young Geun Yoo ; Inho Nam ; Seongjun Bae ; Jongseok Park ; Jeong Woo Han ; Jongheop Yi
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：May 18, 2016
• 年：2016
• 卷：8
• 期：19
• 页码：12186-12193
• 全文大小：517K
• 年卷期：0
• ISSN：1944-8252

文摘

Dodecatitanate H₂Ti₁₂O₂₅ crystal has a condensed layered structure and exhibits noteworthy Li storage performance that makes it an anode material with great potential for use in Li-ion batteries. However, an unknown Li diffusion mechanism and a sluggish level of Li dynamics through elongated diffusion paths inside this crystal has impeded any forward development in resolving its limited rate capability and cyclic stability. In this study, we investigated the Li diffusion dynamics inside the H₂Ti₁₂O₂₅ crystal that play an essential role in Li storage performance. A study of density functional theory combined with experimental evaluation confirmed a strong dependence of Li storage performance on its diffusion. In addition, a nanostructured H₂Ti₁₂O₂₅ containing a bundle of nanorods is developed via the introduction of a kinetic gap during the structural transformation, which conferred a significantly shortened diffusion time/length for Li in H₂Ti₁₂O₂₅. The nanostructured H₂Ti₁₂O₂₅ has high specific capacity (∼230 mAh g^–1) and exhibits enhanced cyclic stability and rate capability compared with conventional bulky H₂Ti₁₂O₂₅. The H₂Ti₁₂O₂₅ proposed in this study has high potential for use as an anode material with excellent safety and stability.