Self-assembly flower-like porous carbon nanosheet powders for higher lithium-ion storage capacity
Self-assembly flower-like porous carbon nanosheet powders for higher lithium-ion storage capacity
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DOI：
10.1016/j.electacta.2015.09.098
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发表时间：
2015-12
影响因子：
6.6
通讯作者：
Zhenhong Ma;Y. Cui;Xiaoxi Zuo;Yanhui Sun;Xin Xiao;J. Nan
中科院分区：
文献类型：
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作者：
Zhenhong Ma;Y. Cui;Xiaoxi Zuo;Yanhui Sun;Xin Xiao;J. Nan
基于自组装和重构的概念，通过喷雾干燥氧化石墨和十六烷基三甲基溴化铵（CTAB）悬浮液，然后进行热还原处理，制备出了几乎是原型石墨粉末理论容量两倍的花状多孔碳纳米片粉末（CNPs）。利用纳米氧化石墨中间体的官能团、边缘和缺陷位点及其与CTAB添加剂的相互作用，构建了具有丰富褶皱的CNP微纳米结构。这种独特的微纳米结构不仅有利于在锂离子电池的阳极衬底上涂覆CNPs，而且提高了它们的电化学性能。具体来说，这些CNPs显示出约807 mAh g - 1的初始比容量和约650 mAh g - 1的稳定容量，在充放电电流为100 mA g - 1的第6次循环后。经过100次循环后仍保持约600 mAh g−1的容量，表明制备的CNPs在锂离子电池中具有良好的应用前景。此外，基于插入/提取“路径记忆效应”，提出了锂离子的存储机制，以解释CNPs中褶皱对容量和循环稳定性的重要性。
Based on the concepts of self-assembly and re-construction, flower-like porous carbon nanosheet powders (CNPs), which exhibit almost double theoretical capacity of prototype graphite powders, are prepared by spray drying a suspension of graphite oxide and cetyltrimethylammonium bromide (CTAB) and subsequent thermally-reducing treatment. The functional groups, edges, and defective sites of nanoscale graphite oxide intermediate and their interaction with CTAB additive are utilized to construct the CNP micro-/nanostructure with abundant wrinkles. This unique micro-/nanostructure not only facilitates coating CNPs on the anode substrate of lithium-ion batteries (LIBs) but also improves their electrochemical performances. Specifically, these CNPs display an initial specific capacity of approximately 807 mAh g−1and a stable capacity of approximately 650 mAh g−1after the 6thcycle at a charge-discharge current of 100 mA g−1. And a capacity of approximately 600 mAh g−1is still kept after 100 cycles, showing the as-prepared CNPs have promising application in the LIBs. In addition, based on the insertion/extraction ‘path-memory effect’, a storage mechanism of lithium ions is proposed to explain the importance of wrinkles in the CNPs to the capacity and cycling stability.