Electroactivity of natural and synthetic triphylite

The electrochemical behavior of three triphylite (LiFePO4) ores from differ ent mining localities has been investigated. Two Of them show clearly an ac tivity corresponding to the triphylite phase. A discharge capacity of 85 mA h g(-1) was obtained. The benefit of heat treatment that allows to deposit the electronically conductive carbon-based coating on the particles is repo rted for both natural and Synthetic LiFePO4 samples, Discharge capacity, ki netics and Stability upon cycling were all improved after the heating proce ss. The best results Were obtained with carbon coatings coming from the dec omposition of a modified polycyclic aromatic. In this case, for synthetic s amples, the whole capacity was reversibly exchanged and less than 1% of the initial capacity was lost after 10 cycles. (C) 2001 Elsevier Science B.V. All rights reserved.