Graphene-like MoS2/amorphous carbon composites with high capacity and excellent stability as anode materials for lithium ion batteries
Graphene-like MoS2/amorphous carbon composites with high capacity and excellent stability as anode materials for lithium ion batteries
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DOI：
10.1039/c1jm10174a
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发表时间：
2011-01-01
影响因子：
--
通讯作者：
Lee, Jim-Yang
中科院分区：
文献类型：
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作者：
Chang, Kun;Chen, Weixiang;Lee, Jim-Yang
开发了一种简便的合成类石墨烯二硫化钼/无定形碳（a - C）复合材料的方法。以钼酸钠、硫脲和葡萄糖为起始原料，首先通过水热法制备了二硫化钼/碳复合材料。在氢气/氮气氛围中于800℃退火后得到类石墨烯二硫化钼/无定形碳复合材料。通过X射线衍射（XRD）、扫描电子显微镜（SEM）、能谱分析（EDS）和高分辨率透射电子显微镜（HRTEM）对样品进行了表征。证实了复合材料中的二硫化钼具有单层结构，即所谓的类石墨烯纳米结构。类石墨烯二硫化钼纳米片均匀地分散在无定形碳中。所测复合材料中相邻类石墨烯二硫化钼纳米片的层间距约为1.0 nm。研究了类石墨烯二硫化钼/无定形碳复合材料的形成机制。类石墨烯二硫化钼/无定形碳复合材料作为锂离子电池负极材料表现出高容量和优异的循环稳定性。在水热溶液中加入1.0 g葡萄糖制备的复合材料展现出最高的可逆容量（962 mAh g⁻¹）和优异的循环稳定性。100次循环后，其容量仍保持在912 mAh g⁻¹。类石墨烯二硫化钼/无定形碳复合材料电化学性能的显著提高可归因于二硫化钼纳米片的类石墨烯结构以及类石墨烯二硫化钼和无定形碳的协同效应。
A facile process to synthesize graphene-like MoS2/amorphous carbon (a-C) composites was developed. MoS2/C composites were firstly prepared by hydrothermal method employing sodium molybdate, sulfocarbamide and glucose as starting materials. The graphene-like MoS2/a-C composites were obtained after annealing at 800 degrees C in H-2/N-2. The samples were characterized by XRD, SEM, EDS and HRTEM. It was confirmed that in the composites MoS2 has a structure of single-layer, which is named graphene-like nanostructure. The graphene-like MoS2 nanosheets were uniformly dispersed in amorphous carbon. The interlaminar distance of the adjacent graphene-like MoS2 nanosheets in the composites measured was similar to 1.0 nm. The mechanism of the formation of the graphene-like MoS2/a-C composites was investigated. The graphene-like MoS2/a-C composites exhibited high capacity and excellent cyclic stability used as anode materials for Li-ion batteries. The composite prepared by adding 1.0 g of glucose in hydrothermal solution exhibited the highest reversible capacity (962 mAh g(-1)) and excellent cyclic stability. After 100 cycles, it still retained 912 mAh g(-1). The significant improvements in the electrochemical properties of the graphene-like MoS2/a-C composites could be attributed to the graphene-like structure of the MoS2 nanosheets and the synergistic effects of graphene-like MoS2 and amorphous carbon.