Optimized Chemical Stability and Electrochemical Performance of LiFePO[sub 4] Composite Materials Obtained by ZnO Coating

An improved electrode performance is achieved in Li Fe P O 4 materials of different origin by a simple coating procedure. Li Fe P O 4 samples were prepared by a conventional ceramic synthesis. Fe 57 Mössbauer data evidenced that heating above 750 ° C with carbon should be avoided to limit the amount of iron phosphide impurities. The ceramic sample was compared to a commercial sample differing in particle size and porous system. ZnO precipitation of a ca. 2 nm films on the particles surface of both phosphate samples resulted in a protection vs electrolyte hydrolysis product that limits iron dissolution during lithium battery operation. As a consequence, capacity retention improves significantly at different rates.