The possibility of manganese disorder in LiMnPO4 and its effect on the electrochemical activity

Orthorhombic structured LiMnPO4 was synthesized by a hydrothermal method. The possibility of manganese disorder in LiMnPO4 was studied using powder X-ray diffraction and X-ray absorption fine structure analysis. A manganese-rich model was proposed for the hydrothermally synthesized LiMnPO4. It is found that the extent of Mn2+ disorder on the Li+ sites was suppressed by increasing the reaction temperature, which led to an enhanced electrochemical activity. These observations are explained on the basis of the manganese-rich model, in which the disordered Mn2+ on the Li+ sites may act as a blockage in one-dimensional lithium ion transport pathway, thus reducing the electrochemical activity of the LiMnPO4 prepared at low temperatures. (C) 2008 Elsevier B.V. All rights reserved.