Electrochemical performances of FePO4-positive active mass prepared through a new sol–gel method

This investigation is a contribution to the research on alternative cathode materials with much more promising performances for lithium batteries. It deals with the electrochemical properties of iron phosphate compound FePO 4 , chemically prepared through the so-called sol–gel Pechini process, terminated by a calcination of the product precursor at temperatures ( T c ) ranging between 350°C and 650°C. A crystalline phase was obtained for temperatures ≥400°C. The particle size decreased with the decrease in T c , giving rise to a Brunauer–Emmett–Teller (BET)-specific surface area, S BET , as high as 28 m 2 g −1 for the sample annealed at 400°C. The electrochemical properties of FePO 4 -based composite cathodes were characterized on three-electrode laboratory cells. Charge–discharge cycling determined a maximum reversible capacity of 132 mAh g −1 , which fell with the increase in T c . A direct correlation was established between the activity of the material and its active surface area.