Abstract

A mixed-solvothermal method was used to synthesize the α-Fe₂O₃ nanoparticles with nearly spherical, rod-like, disk-like morphologies by varying the precipitant or solvent. When used as the anode material for Li-ion batteries, the nearly spherical α-Fe₂O₃ nanoparticles with a high monodispersity and an average diameter of about 50.5 nm exhibited much better cycle stability and rate performance than their disk-like and rod-like equivalents. Their reversible capacity reached up to 1500 mAh/g that far exceeded their theoretical value (1007 mAh/g) at a current density of 0.1 A/g. Even after 100 cycles, there was still a capability retention of about 1200 mAh/g. Moreover, the analysis of the Nyquist plots revealed that the nearly spherical α-Fe₂O₃ nanoparticles presented the lowest charge-transfer resistance among the three samples. The present study provides an effective way to control the morphologies of nanoparticles, and these nanostructures would present great potentials for the applications in LIBs or some other fields.

中文翻译：

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锂离子电池α-Fe2 O 3纳米粒子的混合溶剂热合成及形态相关的电化学性质

摘要

使用混合-溶剂热法合成的α-Fe _2个ö ₃纳米颗粒与近球形，棒状，盘状，通过改变沉淀剂或溶剂的形态。当用作锂离子电池的负极材料使用的，近似球形的α-Fe ₂ ö ₃具有高单分散性且平均直径约为50.5 nm的纳米颗粒比其盘状和棒状等效物具有更好的循环稳定性和速率性能。它们的可逆容量达到1500 mAh / g，在0.1 A / g的电流密度下远远超过其理论值（1007 mAh / g）。即使经过100次循环，容量保持率仍约为1200 mAh / g。此外，奈奎斯特图的分析表明，近球形的α-Fe ₂ ö ₃纳米颗粒所呈现的三个样品中的最低电荷转移电阻。本研究提供了一种控制纳米颗粒形态的有效方法，这些纳米结构将为LIB或其他领域的应用提供巨大潜力。