Yu Peng, Wang Lei, Sun Fanfei, Zhao Dongdong, Tian Chungui, Zhao Lu, Liu Xu, Wang Jianqiang, Fu Honggang
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080 (P. R. China), Fax: (+86) 451-8666-1259.
Chemistry. 2015 Feb 16;21(8):3249-56. doi: 10.1002/chem.201406188. Epub 2015 Jan 9.
Nanostructured iron compounds as lithium-ion-battery anode material have attracted considerable attention with respect to improved electrochemical energy storage and excellent specific capacity, so lots of iron-based composites have been developed. Herein, a novel composite composed of three-dimensional Fe2 N@C microspheres grown on reduced graphite oxide (denoted as Fe2 N@C-RGO) has been synthesized through a simple and effective technique assisted by a hydrothermal and subsequent heating treatment process. As the anode material for lithium-ion batteries, the synthetic Fe2 N@C-RGO displayed excellent Li(+) -ion storage performance with a considerable initial capacity of 847 mAh g(-1) , a superior cycle stability (a specific discharge capacity of 760 mAh g(-1) remained after the 100th cycle), and an improved rate-capability performance compared with those of the pure Fe2 N and Fe2 N-RGO nanostructures. The good performance should be attributed to the existence of RGO layers that can facilitate to enhance the conductivity and shorten the lithium-ion diffusion path; in addition, the carbon layer on the surface of Fe2 N can avert the structure decay caused by the volume change during the lithiation/delithiation process. Moreover, in situ X-ray absorption fine-structure analysis demonstrated that the excellent performance can be attributed to the lack of any obvious change in the coordination geometry of Fe2 N@C-RGO during the charge/discharge processes.
作为锂离子电池负极材料的纳米结构铁化合物，因其在改善电化学储能和优异比容量方面的表现而备受关注，因此人们开发了许多铁基复合材料。在此，通过水热法和后续热处理工艺辅助的简单有效技术，合成了一种由生长在还原氧化石墨烯上的三维Fe₂N@C微球组成的新型复合材料（记为Fe₂N@C-RGO）。作为锂离子电池的负极材料，合成的Fe₂N@C-RGO表现出优异的锂离子存储性能，初始容量可观，为847 mAh g⁻¹，循环稳定性优异（第100次循环后仍保持760 mAh g⁻¹的比放电容量），并且与纯Fe₂N和Fe₂N-RGO纳米结构相比，倍率性能有所提高。良好的性能应归因于RGO层的存在，它有助于提高导电性并缩短锂离子扩散路径；此外，Fe₂N表面的碳层可以避免在锂化/脱锂过程中因体积变化而导致的结构衰减。此外，原位X射线吸收精细结构分析表明，优异的性能可归因于Fe₂N@C-RGO在充放电过程中配位几何结构没有明显变化。
