Self-Assembly of Co3V2O8 Multi layered Nanosheets: Controllable Synthesis, Excellent Li-Storage Properties, and Investigation of Electrochemical Mechanism
Self-Assembly of Co3V2O8 Multi layered Nanosheets: Controllable Synthesis, Excellent Li-Storage Properties, and Investigation of Electrochemical Mechanism
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DOI：
10.1021/nn406449u
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发表时间：
2014-05-01
期刊：
影响因子：
17.1
通讯作者：
Wang, Chengxin
中科院分区：
文献类型：
--
作者：
Yang, Gongzheng;Cui, Hao;Wang, Chengxin
开发具有高能量密度和高功率密度的电极材料是满足世界范围内能源存储迫切需求的关键。在此，我们证明了通过简单的水热方法自组装超薄纳米片，然后在空气中在350摄氏度下退火2小时，成功制备了Co 3 V2 O 8纳米结构。提出了一个基于时间依赖性实验的“滑动-剥离-自组装”模型来解释分级纳米片的形成。当作为锂离子阳极测试时，所合成的多层纳米结构表现出优异的可逆容量（100次循环后保持1114 mA h g（-1））和优异的速率性能（在10 A g（-1）的高电流密度下为361 mA h g（-1））用于锂存储。详细的形态和结构变化的Co 3V 2 O 8循环后的调查揭示了一个有趣的动力学锂离子嵌入，其中钴和CoO之间的可逆转化反应被发现进行非晶锂化钒氧化物矩阵。我们认为，这一观察结果对于基于金属破坏物的锂离子阳极是一个有价值的发现。多层Co 3V 2 O 8纳米片的上级电化学性能可以归因于独特的形貌，特别是在锂离子插入过程中产生的表面到表面的结构。
Developing electrode materials with both high energy and power densities holds the key for satisfying the urgent demand of energy storage worldwide. Herein, we demonstrate the successful preparation of Co3V2O8 nanostructures that are constructed from self-assembly of ultrathin nanosheets via a simple hydrothermal method followed by annealing in air at 350 degrees C for 2 h. A "slipping-exfoliating-self reassembly" model based on the time-dependent experiments was proposed to elucidate the formation of the hierarchical nanosheets. When tested as lithium ion anodes, the as-synthesized multilayered nanoarchitectures exhibit outstanding reversible capacity (1114 mA h g(-1) retained after 100 cycles) and excellent rate performance (361 mA h g(-1) at a high current density of 10 A g(-1)) for lithium storage. Detailed investigations of the morphological and structural changes of Co3V2O8 upon cycling reveal an interesting kinetics toward lithium ion intercalations, where reversible conversion reactions between Co and CoO are found proceeding on the amorphous lithiated vanadium oxides matrixes. We believe that this observation is a valuable discovery for metal vandates-based lithium ion anodes. The superior electrochemical performances of the multilayered Co3V2O8 nanosheets can be attributed to the unique morphologies and particularly the surface-to-surface constructions that are generated during the lithium ion insertion processes.