POSITIVE ELECTRODE ACTIVE MATERIAL WITH ENHANCED ELECTRODE EFFICIENCY AND ENERGY DENSITY CHARACTERISTICS

Provided is a cathode active material having a composition represented by the following Formula I: LiFe(P)O) (I) wherein a molar fraction (1-x) of phosphorus (P) is in the range of 0.910 to 0.999, to allow operational efficiency of the cathode active material to be leveled to a lower operational efficiency of an anode active material and improve energy density of the cathode active material. Furthermore, a cathode active material, wherein a molar fraction (1-x) of phosphorus (P) is lower than 1, contains both Feand Fethus advantageously preventing structural deformation, improving ionic conductivity, exhibiting superior rate properties and inhibiting IR drop upon charge/discharge, thereby imparting high energy density to batteries.