Enhanced Cyclability of Li鈥揙2 Batteries Based on TiO2 Supported Cathodes with No Carbon or Binder

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• 作者：Guangyu Zhao ; Runwei Mo ; Baoyu Wang ; Li Zhang ; Kening Sun
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：April 22, 2014
• 年：2014
• 卷：26
• 期：8
• 页码：2551-2556
• 全文大小：397K
• 年卷期：v.26,no.8(April 22, 2014)
• ISSN：1520-5002

文摘

The decomposition of carbon materials and organic binders in Li鈥揳ir batteries has been reported repeatedly in recent literature. The decomposition of carbon can harm the batteries鈥?cyclability further by catalyzing electrolyte degrading. Therefore, there is a critical need to exploit a new catalyst support substituting carbon and develop a binder free cathode preparation strategy for Li鈥揳ir batteries. Herein, TiO₂ nanotube arrays growing on Ti foam are used as the catalyst support to construct carbon and binder free oxygen diffusion electrodes. After being coated with Pt nanoparticles by a cool sputtering approach, the TiO₂ nanotube arrays are used as cathodes of Li鈥揙₂ batteries. Benefiting from the stability of TiO₂ in the discharge/charge processes, the Li鈥揙₂ batteries realize enhanced cyclability at high current densities (for instance, more than 140 cycles at 1 or 5 A g^鈥?), within wide discharge/charge voltage windows (for instance, 1.5鈥?.5 V). X-ray photoelectron spectra and a scanning electron microscope image of the cathodes after cycling at 5 A g^鈥? 150 times indicate that the TiO₂ nanotubes can remain stable in the long term cycle test. ¹H nuclear magnetic resonance analysis reveals that the tetraethylene glycol dimethyl ether electrolyte has no degradation, showing enhanced stability compared with that in the carbon containing batteries.