On the way to the optimization of Li_3Fe_2(PO_4)_3 positive electrode materials

摘要

The electrochemical performances of the two polymorphs of Li_3Fe_2(Po_4)_3 are reported. We show that reversible capacities as high as 110 mA hg~(-1) at C/20 regime with an excellent capacity retention are obtained by playing with particle sizes and surface. Tailored made particles were done chemically, by developing a new low temperature synthetic route. In contrast, the modification of the particle surface was achieved by ball-milling of carbon/Li_3Fe_2(Po_4)_3 mixtures, confirming again the positive attribute of such process regarding the electrochemical performances of transition metal phosphates.