| abstract |
The present invention relates to a positive electrode active material for a lithium secondary battery, comprising a compound represented by formula 1, a preparing method of the positive electrode active material, and a rechargeable lithium battery comprising the positive electrode active material, wherein the molar content of lithium present in the structure of the positive electrode active material, measured through neutron diffraction analysis, is 1.02 to 1.15 with respect to 1 mole of the positive electrode active material, and a change of a c-lattice constant in R-3m structure according to charging/discharging in a range of 2.5 V to 4.25 V is less than 2.3%. [Formula 1] Li 1+a (Ni b M 1 n 1-b ) 1-a O 2 , wherein in formula 1, 0<a<0.2, 0.8<b<1, and M 1 is at least one element selected from among Co, Mn, Al, Mg, Ca, Ti, V, Cr, Zr, Nb, Mo, and W. |