Mesoporous and Nanostructured TiO₂ layer with Ultra-High Loading on Nitrogen-Doped Carbon Foams as Flexible and Free-Standing Electrodes for Lithium-Ion Batteries

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• 作者：Shiyong Chu ; Yijun Zhong ; Rui Cai ; Zhaobao Zhang ; Shenying Wei and Zongping Shao
• 刊名：Small
• 出版年：2016
• 出版时间：December 28, 2016
• 年：2016
• 卷：12
• 期：48
• 页码：6724-6734
• 全文大小：2388K
• ISSN：1613-6829

文摘

A simple and green method is developed for the preparation of nanostructured TiO₂ supported on nitrogen-doped carbon foams (NCFs) as a free-standing and flexible electrode for lithium-ion batteries (LIBs), in which the TiO₂ with 2.5–4 times higher loading than the conventional TiO₂-based flexible electrodes acts as the active material. In addition, the NCFs act as a flexible substrate and efficient conductive networks. The nanocrystalline TiO₂ with a uniform size of ≈10 nm form a mesoporous layer covering the wall of the carbon foam. When used directly as a flexible electrode in a LIB, a capacity of 188 mA h g⁻¹ is achieved at a current density of 200 mA g⁻¹ for a potential window of 1.0–3.0 V, and a specific capacity of 149 mA h g⁻¹ after 100 cycles at a current density of 1000 mA g⁻¹ is maintained. The highly conductive NCF and flexible network, the mesoporous structure and nanocrystalline size of the TiO₂ phase, the firm adhesion of TiO₂ over the wall of the NCFs, the small volume change in the TiO₂ during the charge/discharge processes, and the high cut-off potential contribute to the excellent capacity, rate capability, and cycling stability of the TiO₂/NCFs flexible electrode.