Atomic Cobalt Covalently Engineered Interlayers for Superior Lithium-Ion Storage
Atomic Cobalt Covalently Engineered Interlayers for Superior Lithium-Ion Storage
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用于卓越锂离子存储的原子钴共价设计夹层
DOI：
10.1002/adma.201802525
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发表时间：
2018
影响因子：
29.4
通讯作者：
Song Li
中科院分区：
文献类型：
--
作者：
Wang Changda;Xie Hui;Chen Shuangming;Ge Binghui;Liu Daobin;Wu Chuanqiang;Xu Wenjie;Chu Wangsheng;Babu Ganguli;Ajayan Pulickel M.;Song Li
MXenes具有独特的层状结构，可作为储能设备（包括锂离子（Li+）电容器和电池）的电极。然而，低的Li+储存容量阻碍了MXene代替商业碳材料的应用。在这里，碳化钒（V2 C）MXene与设计的层间距所需的存储容量进行了演示。原始V2 C MXene的层间距离可控地调节到0.735 nm，从而在0.1 A g−1下提高了686.7 mA h g− 1的Li离子容量，这是迄今为止报道的最佳MXene基Li+存储容量。此外，钴离子稳定地插入V2 C MXene的层间，通过强V-O-Co键合形成新的层间扩展结构。插层V2 C MXene电极不仅在0.1 A g−1下表现出高达1117.3 mA h g−1的上级容量，而且在15000次循环中具有显著的超长循环稳定性。这些结果清楚地表明，具有工程化层间距离的MXene材料将是实现它们作为超稳定和高性能Li+电容器电极的合理途径。
With the unique‐layered structure, MXenes show potential as electrodes in energy‐storage devices including lithium‐ion (Li+) capacitors and batteries. However, the low Li+‐storage capacity hinders the application of MXenes in place of commercial carbon materials. Here, the vanadium carbide (V2C) MXene with engineered interlayer spacing for desirable storage capacity is demonstrated. The interlayer distance of pristine V2C MXene is controllably tuned to 0.735 nm resulting in improved Li‐ion capacity of 686.7 mA h g−1at 0.1 A g−1, the best MXene‐based Li+‐storage capacity reported so far. Further, cobalt ions are stably intercalated into the interlayer of V2C MXene to form a new interlayer‐expanded structure via strong V–O–Co bonding. The intercalated V2C MXene electrodes not only exhibit superior capacity up to 1117.3 mA h g−1at 0.1 A g−1, but also deliver a significantly ultralong cycling stability over 15 000 cycles. These results clearly suggest that MXene materials with an engineered interlayer distance will be a rational route for realizing them as superstable and high‐performance Li+capacitor electrodes.