Fine Lithium Iron(II) Phospho-Olivine Prepared by Different Methods

摘要

The electroactive materials LiFePO_4, Li_(0.98)Mg_(0.01)FePO_4 and carbon-coated LiFePO_4 were synthesized by an improved solid-state reaction and by a sol-gel process and characterized by XRD, SEM, and their electrochemical performance. The reaction conditions favor stabilization of the iron as Fe~(2+) as well as offering some control of the product morphology and particle size. Electrochemical evaluation of the products reveals a lithium insertion plateau around 3.4V vs Li. Excellent electro- chemical properties in terms of capacity, reversibility and cycling stability have been achieved for doped LiFePO_4 synthesized by an improved solid-state reaction. The two methods all produced pure, fine and homogeneous particles.