Improvement of the Electrochemical Properties in Nano-Sized Al2O3 and AlF3-Coated LiFePO4 Cathode Materials
The surface conditions of LiFePO4 powder were modified by adding AlF3 and Al2O3 by using the sol-gel process to improve its electrochemical properties. The surface of LiFePO4 powders was partially covered with nano-sized AlF3 and Al2O3, which is confirmed by using a transmission electron microscope image. The states of coated Al materials were examined by using X-ray photoelectron spectrometer results. The nano-sized AlF3- and Al2O3-coated LiFePO4 powders showed no difference in the bulk structure compared with the pristine one. However, the AlF3- and Al2O3-coating on LiFePO4 powders improved the overall electrochemical properties such as the discharge capacity, the cyclability, and the rate capability compared with those of a pure LiFePO4. Such enhancements were attributed to the presence of a stable AlF3 and Al2O3 layer which acts as an interfacial stabilizer on the surface of LiFePO4 powders.
Andreas Öchsner, Graeme E. Murch, Ali Shokuhfar and João M.P.Q. Delgado
C.W. Ahn et al., "Improvement of the Electrochemical Properties in Nano-Sized Al2O3 and AlF3-Coated LiFePO4 Cathode Materials", Defect and Diffusion Forum, Vols. 297-301, pp. 906-911, 2010