화학공학소재연구정보센터
Journal of Power Sources, Vol.196, No.4, 2155-2163, 2011
More on the reactivity of olivine LiFePO4 nano-particles with atmosphere at moderate temperature
The changes appearing for LiFePO4-C nano-composites exposed to atmosphere at 120 C have been structurally and chemically examined by the use of TGA XRD XPS Mossbauer Li-7 MAS NMR and electrochemical methods The results conclude that a highly disordered phase resulting from the aging of LiFePO4 appears on the surface of the grains of the material is assigned to a phosphate phase and can insert lithium around 2 6V with poor reversibility The essential role of water has been investigated and clearly demonstrated Thus the aging mechanism occurring in hot humid air is completely different from a simple oxidation as well as from the aging process observed above 150 C and Involves the incorporation of hydroxyl groups In addition Fe2O3 formation has not been observed for such an aging in mild conditions (C) 2010 Elsevier B V All rights reserved