Li-ion uptake and increase in interlayer spacing of Nb4C3 MXene
Li-ion uptake and increase in interlayer spacing of Nb4C3 MXene
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DOI：
10.1016/j.ensm.2017.03.012
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发表时间：
2017-07
影响因子：
20.4
通讯作者：
Shuangshuang Zhao;Xing Meng;K. Zhu;Fei Du;Gang Chen;Yingjin Wei;Y. Gogotsi;Yu Gao
中科院分区：
文献类型：
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作者：
Shuangshuang Zhao;Xing Meng;K. Zhu;Fei Du;Gang Chen;Yingjin Wei;Y. Gogotsi;Yu Gao
二维（2D）碳化物，MXenes，已经显示出用于电化学能量存储的前景，但大多数研究都是在碳化钛上进行的。在这里，我们报告锂插入到2D Nb 4C 3 TxMXene，通过在室温下在HF中从Nb 4AlC 3中蚀刻铝形成。Nb 4C 3 Tx的理论容量尚未研究，但当作为锂离子电池的阳极进行测试时，它显示出比所生产的碳化钛和其他MXene更高的容量。此外，Nb 4C 3 Tx阳极的充/放电容量随着循环而增加。例如，在100次充放电循环之后，在0.1A g-1的电流密度下，比容量从310 mA h g-1（194 mA h cm-3）增加到380 mA h g-1（238 mA h cm-3），并且在1A g-1下，容量从116 mA h g-1（73 mA h cm-3）增加到320 mA h g-1（200 mA h cm-3）。已经证明了优异的倍率性能和在高倍率下的优异的上级长期稳定性。这项工作有望激发MXene用于高性能锂离子电池和电容器的进一步探索。由于Nb 4C 3 Ti只是许多MXene中的一种，因此存在很大的空间来改善MXene的电子导电层状结构的可及性并实现更好的电化学性能。
Two-dimensional (2D) carbides, MXenes, have shown promise for electrochemical energy storage, but most studies were conducted on titanium carbides. Herein we report on Li insertion into a 2D Nb4C3TxMXene, formed by etching aluminum from Nb4AlC3in HF at room temperature. The theoretical capacity of Nb4C3Txhas not been studied, but it displayed a higher capacity than as-produced titanium carbide and other MXenes, when tested as anode for lithium ion batteries. In addition, the charge/discharge capacity of the Nb4C3Txanode increases with cycling. For instance, after 100 charge/discharge cycles, the specific capacity increased from 310 mA h g−1(194 mA h cm−3) to 380 mA h g−1(238 mA h cm−3), at a current density of 0.1 A g−1, and the capacity increased from 116 mA h g−1(73 mA h cm−3) to 320 mA h g−1(200 mA h cm−3) at 1 A g−1. Excellent rate capability and superior long-term stability at the ultrahigh rates have been demonstrated. This work is expected to inspire further exploration of MXenes for high-performance Li-ion batteries and capacitors. Since Nb4C3Txis just one of many MXenes, there is much room for improving the accessibility of the electronically conducting layered structures of MXenes and achieving a better electrochemical performance.