Aligned Ti3C2Tx Electrodes Induced by Magnetic Field for High-Performance Lithium-Ion Storage
Aligned Ti3C2Tx Electrodes Induced by Magnetic Field for High-Performance Lithium-Ion Storage
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DOI：
10.1021/acsaem.1c00361
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发表时间：
2021-06
期刊：
影响因子：
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通讯作者：
Li Zhang;Mingyang Zeng;Ziqiang Liu;Quanhu Ma;Yulan Lu;Jun Ma;Xingbin Yan
中科院分区：
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作者：
Li Zhang;Mingyang Zeng;Ziqiang Liu;Quanhu Ma;Yulan Lu;Jun Ma;Xingbin Yan
二维过渡金属碳化物/氮化物（简称MXenes）具有化学结构多样性、上级导电性和高比表面积等优点，在锂离子电池负极方面具有很大的应用前景，但其中间层不可避免的再堆叠和坍塌阻碍了Li+的传输，严重限制了其实际应用。在此，我们设计了通过石墨辅助磁对准技术的Ti 3C 2 Tx电极。石墨的引入不仅支撑Ti 3C 2 Tx薄片以实现取向结构，这有利于离子扩散，而且还充当高导电介质以促进电子转移。此外，石墨赋予锂存储容量，从而协同改善Ti 3C 2 Tx电极的电化学性能。因此，将电极的取向结构与协同效应相结合，取向的Ti 3 C 2 Tx电极在50 mA g-1下提供196. 5 mAh g-1，并且表现出优异的上级倍率性能和长循环稳定性（在2 A g-1下比容量是没有取向结构的电极的比容量的3. 6倍，并且在5000次循环后保持90%）。定向Ti 3C 2 Tx电极有望实现实际应用。此外，磁取向技术有望扩展到其他二维材料的工程设计，作为一种通用的策略，以满足优异的性能要求。
The promising two-dimensional transition-metal carbides/nitrides (named MXenes) present extremely competitive potential applications as anode of Li-ion battery owing to their advantages such as chemical diversity, superior conductivity, and high specific surface area, but the inevitable restack and collapse of interlayers hinder Li+transport and thus severely restrict the practical applications. Herein, we designed aligned Ti3C2Txelectrodes via graphite-assisted magnetic alignment technique. The introduction of graphite not only supports Ti3C2Txflakes to achieve the aligned structure, which is beneficial to ion diffusion, but also acts as a highly conductive medium to facilitate electron transfer. Moreover, graphite endows the lithium storage capacity, thus improving synergistically the electrochemical properties of Ti3C2Txelectrodes. Hence, combining the aligned structure of the electrode with synergistic effects, the aligned Ti3C2Txelectrode delivers 196.5 mAh g–1at 50 mA g–1and exhibits superior rate performance and long cycle stability (the specific capacity is 3.6 times more than that of the electrode without an alignment structure at 2 A g–1and retains 90% after 5000 cycles). The aligned Ti3C2Txelectrode is promising to achieve the practical applications. Furthermore, the magnetic alignment technique is expected to be extended to engineer other two-dimensional materials as a universal strategy for the requirement of excellent properties.