Rapid Amorphization in Metastable CoSeO3•H2O Nanosheets for Ultrafast Lithiation Kinetics
Rapid Amorphization in Metastable CoSeO3•H2O Nanosheets for Ultrafast Lithiation Kinetics
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亚稳态 CoSeO3 中心点 H2O 纳米片的快速非晶化用于超快锂化动力学
DOI：
10.1021/acsnano.8b02352
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发表时间：
2018-05-01
期刊：
影响因子：
17.1
通讯作者：
Hu, Linfeng
中科院分区：
文献类型：
--
作者：
Jiang, Yingchang;Song, Yun;Hu, Linfeng
对于电动汽车等高功率应用而言，实现高性能负极材料具有高容量、快速的锂化动力学和优异的循环稳定性仍然是一个重大而关键的挑战。二维纳米结构因其耐人寻味的表面效应和显著减少离子扩散途径而在电化学储能装置中引起了广泛的研究兴趣。本文介绍了用简易水热法合成的用作锂离子电池负极的亚稳态CoSeO_3中心点状H_2O纳米片。这种晶态纳米片在第一次Le放电循环开始时就可以稳定地转变为非晶相，以3和10Ag(-1)的高倍率循环1000次后，可获得1100和515mAhg(-1)的超高可逆容量。所得到的非晶态结构经历了各向同性的应力，这可以显著降低电化学循环过程中的断裂风险。我们的研究为揭示与层状硒化钴纳米片的快速非晶化机制相关的超快锂化动力学提供了宝贵的机会。
The realization of high-performance anode materials with high capacity at fast lithiation kinetics and excellent cycle stability remains a significant but critical challenge for high-power applications such as electric vehicles. Two-dimensional nanostructures have attracted considerable research interest in electrochemical energy storage devices owing to their intriguing surface effect and significantly decreased ion-diffusion pathway. Here we describe rationally designed metastable CoSeO3 center dot H2O nano sheets synthesized by a facile hydrothermal method for use as a Li ion battery anode. This crystalline nanosheet can be steadily converted into amorphous phase at the beginning of the first Le discharge cycling, leading to ultrahigh reversible capacities of 1100 and 515 mAh g(-1) after 1000 cycles at a high rate of 3 and 10 A g(-1), respectively. The as-obtained amorphous structure experiences an isotropic stress, which can significantly reduce the risk of fracture during electrochemical cycling. Our study offers a precious opportunity to reveal the ultrafast lithiation kinetics associated with the rapid amorphization mechanism in layered cobalt selenide nanosheets.