wang hay kan - Synthesis of nanocrystals and morphology control of hydrothermally prepared LiFePO4

Version 1

      Publication Details (including relevant citation   information):

      B. Ellis, Wang Hay Kan, W. R. M. Makahnouk and L. F. Nazar

      J. Mater. Chem., 2007,   17, 3248-3254


      Lithium transition metal phosphate olivines such as   LiFePO4 have been recognized as very   promising electrodes for lithium-ion batteries because of their   energy storage capacity combined with electrochemical and thermal   stability. A key issue in these materials is to determine the   synthetic conditions for optimum control of particle size and   morphology, and ideally to find those that result in   nanocrystalline products. Here, we report a full study that   examines the synthesis of the material via hydrothermal   methods to give single phase nanocrystalline materials for   LiFePO4 and   LiMnPO4, and their solid solutions with   Mg2+. A reaction mechanism is proposed.   Variation of the synthesis parameters showed that increasing   reactant concentration strongly favours the formation of   nanocrystalline products, but as less defect-free materials are   formed at temperatures above 180 °C, and ideally above 200 °C,   control of nucleation and growth can (and should) also be   effected using polymeric or surfactant additives. The nature of   the precursor and carbon-containing additives in the autoclave   also have profound effects on morphology and the electrochemical   properties.

      Address (URL):