Tuning the carbon content on TiO₂ nanosheets for optimized sodium storage

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• 作者：Yanfen Wen ; Jung-Ho Yun ; Bin Luo ; Miaoqiang Lyu ; Lianzhou Wang ; ^{l.wang@uq.edu.au" class="auth_mail" title="E-mail the corresponding author}
• 关键词：TiO2 nanosheets ; Carbon coating ; Anode ; Sodium storage
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：20 November 2016
• 年：2016
• 卷：219
• 期：Complete
• 页码：163-169
• 全文大小：3170 K

文摘

Titanium dioxide (TiO₂) has been considered as a promising anode candidate for sodium ion batteries (NIBs). In this work, we report the synthesis of anatase TiO₂ nanosheets coated by nitrogen doped carbon derived from dopamine precursor (TiO₂@C) as high performance anode materials for NIBs applications. The carbon contents can be controlled from 2.6 wt% to 10.4 wt% by varying the polymerization time of dopamine. X-ray diffraction patterns confirm there is no phase change after carbon coating. When employed as an anode for NIBs, the TiO₂@C composites exhibit improved electrochemical performances in terms of higher specific capacity and better cycling stability compared to pure TiO₂ nanosheets. Notably, with a carbon content of 4.8 wt%, the TiO₂@C nanosheets delivers a reversible capacity of 180 mA h g⁻¹ and shows stable cycling performance with no discharge capacity decay from 2nd cycle onward over 50 cycles. Even at high current density of 10C, the capacity still remains 82 mA h g⁻¹. The excellent cycling stability and rate performances can be ascribed to the protective effects of carbon coating layer which reserves the structure stability and enhances electrical conductivity during cycling.