Electrochemical properties of self-assembled porous micro-spherical LiFePO4/PAS composite prepared by spray-drying method

Polyacene (PAS) coated self-assembled porous micro-spherical LiFePO4 cathode material is successfully synthesized by spray drying method. The crystal structure of the sample is examined by X-ray diffraction (XRD). The micro-spherical morphology with porous structure is observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical properties are investigated via galvanostatic charge-discharge experiments and electrochemical impedance spectroscopy (EIS) analysis. The material exhibits a high lithium ion diffusion coefficient about 10(-12) cm(2) S-1, excellent electrochemical properties and good cyclability. The initial discharge capacity is as high as 168 mAh/g at 0.1 C rate, and the capacity retention is approximately 100% after 100 cycles at 1 C rate, almost no capacity fading. All demonstrate that self-assembled micro-spherical particles with nano primary particles and porous structure are benefit to improve the electrochemical performance of cathode materials. (C) 2015 Elsevier Ltd. All rights reserved.