A PVB-based rheological phase approach to nano-LiFePO4/C composite cathodes

Nano-LiFePO4/C cathode materials were synthesized by a PVB-based theological phase method, followed by calcination at 550 degrees C for 10 h in argon. Simultaneous thermogravimetric-differential scanning calorimetry analysis indicates that the crystallization temperature of LiFePO4 is about 436 degrees C. In the process of heat treatment, the decomposition of polyvinylbutyral coats carbon on the synthesized LiFePO4 particles in situ. The resulting LiFePO4 powders with fine particle sizes and homogeneous carbon network connection were observed by using scanning electron microscopy and transmission electron microscopy. Electrochemical measurements show that the LiFePO4/C composite cathode delivers a large discharge capacity of 162.3 mAh.g(-1) 1 at the 0.1 C rate, and exhibits a favorable capacity cycling maintenance at lower charge and discharge rate such as 0.5 C rate. (c) 2007 Elsevier B.V. All rights reserved.