MnO nanocrystals incorporated in a N-containing carbon matrix for Li ion battery anodes
MnO nanocrystals incorporated in a N-containing carbon matrix for Li ion battery anodes
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DOI：
10.1039/c6ra00571c
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发表时间：
2016-03
期刊：
影响因子：
3.9
通讯作者：
Chunyu Zhu;Cheng-Gong Han;G. Saito;T. Akiyama
中科院分区：
文献类型：
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作者：
Chunyu Zhu;Cheng-Gong Han;G. Saito;T. Akiyama
在本研究中，通过硝酸锰-甘氨酸凝胶的易热分解制备了含n碳基质中的MnO纳米晶体。通过控制锰与甘氨酸的初始比例，制备了不同碳含量的MnO/C复合材料。采用x射线衍射、x射线光电子能谱、拉曼光谱、扫描电镜和透射电镜以及热重分析对复合材料的组成、相结构和形貌进行了表征。结果表明，MnO纳米晶体均匀地嵌套在n掺杂碳基体中。碳基体可以有效地提高MnO的电导率，减轻充放电循环产生的应变。该复合材料具有较高的充放电能力、优良的循环性能和优良的倍率性能。在0.5 A g−1的放电和充电速率下，经过110次循环，获得了556 mA h g−1的高可逆容量。即使在3 a g−1的高电流下，样品仍然提供约286 mA h g−1的容量。简单的生产和优异的电化学性能使复合材料成为高性能锂离子电池阳极替代品的有希望的候选者。
In this study, MnO nanocrystals incorporated in a N-containing carbon matrix were fabricated by the facile thermal decomposition of manganese nitrate-glycine gels. MnO/C composites with different carbon contents were prepared by controlling the initial ratio of manganese to glycine. The composition, phase structure and morphology of the composites were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, scanning and transmission electron microscopy, and thermogravimetric analysis. The results indicated that MnO nanocrystals were uniformly embedded in the N-doped carbon matrix. The carbon matrix could effectively enhance the electrical conductivity of MnO and alleviate the strain arising from the discharge/charge cycling. The composite materials exhibited high discharge/charge capacities, superior cycling performance, and excellent rate capability. A high reversible capacity of 556 mA h g−1 was obtained after 110 cycles of discharging and charging at a current rate of 0.5 A g−1. Even at a high current rate of 3 A g−1, the sample still delivered a capacity of around 286 mA h g−1. The easy production and superior electrochemical properties enables the composites to be a promising candidate as an anode alternative for high-performance lithium-ion batteries.