Molten salt synthesis and electrochemical properties of spherical LiFePO 4 particles

• Published in: Materials letters Vol. 61; no. 4; pp. 1260 - 1264
• Main Authors: Ni, Jiang-Feng, Zhou, Heng-Hui, Chen, Ji-Tao, Zhang, Xin-Xiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2007
• Subjects: Electrochemical performance; Lithium iron phosphate; Molten salt; Spherical; Volumetric energy density; Spherical; Electrochemical performance; Volumetric energy density; Lithium iron phosphate; Molten salt
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2006.07.006

Well-crystallized LiFePO 4 was directly synthesized by the KCl molten salt (MS) method. According to this method, the pre-sintered intermediate was mixed with KCl, and then sintered at a certain temperature, which was determined by thermogravimetric analysis (TGA). The olivine structure and spherical morphology were confirmed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The spherical products show a higher tap density, which will benefit the enhancement of volumetric energy density. The electrochemical behavior was studied by cyclic voltammetry and galvanostatic tests. The LiFePO 4 product sintered at 755 °C for 3 h exhibits the best electrochemical performance. At a rate of 0.1 C, it can deliver an initial capacity of 130.3 mAh g − 1 , and a capacity of 137.2 mAh g − 1 at the 40th cycle. At a high discharge rate of 5 C, it still exhibits a capacity of 92 mAh g − 1 .