用于锂离子电池的磷酸铁锂正极材料的可控合成、形貌演变及电化学性能

Controllable synthesis, morphology evolution and electrochemical properties of LiFePO4 cathode materials for Li-ion batteries.

作者信息

Song Jianjun, Wang Lin, Shao Guangjie, Shi Meiwu, Ma Zhipeng, Wang Guiling, Song Wei, Liu Shuang, Wang Caixia

机构信息

Hebei Key Laboratory of Applied Chemistry, College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, China.

出版信息

Phys Chem Chem Phys. 2014 May 7;16(17):7728-33. doi: 10.1039/c4cp00251b.

DOI:10.1039/c4cp00251b

PMID:24638079

Abstract

Monodispersed LiFePO4 nanocrystals with diverse morphologies were successfully synthesized via a mild and controllable solvothermal approach with a mixture of ethylene glycol and oleic acid as the solvent. Morphology evolution of LiFePO4 nanoparticles from nanoplates to nanorods can be simply realized by varying the volume ratio of oleic acid to ethylene glycol. Moreover, the mechanism of competitive adsorption between ethylene glycol and oleic acid was proposed for the formation of different morphologies. Electrochemical measurements show that the LiFePO4/C nanorods have an initial discharge capacity of 155 mA h g(-1) at 0.5 C with a capacity retention of 80% at a high rate of 5 C, which confirms that LiFePO4/C nanorods exhibit excellent rate capability and cycling stability.

摘要

通过以乙二醇和油酸的混合物为溶剂的温和且可控的溶剂热法，成功合成了具有多种形态的单分散磷酸铁锂纳米晶体。通过改变油酸与乙二醇的体积比，可以简单地实现磷酸铁锂纳米颗粒从纳米片到纳米棒的形态演变。此外，还提出了乙二醇和油酸之间的竞争吸附机制来解释不同形态的形成。电化学测量表明，LiFePO₄/C纳米棒在0.5 C时的初始放电容量为155 mA h g⁻¹，在5 C的高倍率下容量保持率为80%，这证实了LiFePO₄/C纳米棒具有优异的倍率性能和循环稳定性。