Moisture driven aging mechanism of LiFePO4 subjected to air exposure

作者：Cuisinier Marine^*; Martin Jean Frederic; Dupre Nicolas; Yamada Atsuo; Kanno Ryoji; Guyomard Dominique

来源：Electrochemistry Communications, 2010, 12(2): 238-241.

DOI：10.1016/j.elecom.2009.12.003

• Li-ion
• Cathode
• LiFePO4
• Aging
• Moisture

The impact of air exposure on LiFePO4-C nanocomposites has been investigated at moderate temperature. We show here that the storage in 120 degrees C hot air for 30 days leads not only to the material delithiation but also to the formation of an amorphous ferric phosphate side-phase, accounting for 38% of the total iron. The formed phase is found to be partially hydrated, suggesting a water-driven aging mechanism and a proposed hypothetic formula: LixFePO4(OH)(x). The side-phase displays new electrochemical activity but poor cyclability and the overall battery performance is thus deteriorated. The regeneration of pristine structure, together with the performance recovery can be achieved by a simple thermal treatment under inert atmosphere.

• 出版日期2010-2