POSITIVE ACTIVE MATERIALS SHOWING RELATIVE SIZE OF PEAK WITH SPECIFIC RANGE IN LAMAN SPECTRUM

摘要

PURPOSE: Provided are positive active materials which are possibly used for evaluating the performance of cells before completing the cells to reduce time and cost in developing the active materials. CONSTITUTION: The lithium positive active material is represented by formula: LixCoyM(1-y)A2, in which 0.95=x=1.0, 0=y=1, M is not less than one atom selected from groups which are composed of Ni, Fe, Pb, Mg, Al, K, Na, Ca, Si, Ti, Sn, V, Ge, Ga, B, As, Zr, Mn and Cr and A is selected from O, F, S or P. In Raman spectrum analysis, the ratio of peak intensity at A1g vibration mode of spinel structure and peak intensity at A1g vibration mode of hexagonal structure is 1:0.1-0.4, that of peak intensity at A1g vibration mode of hexagonal structure and peak intensity at Eg vibration mode is 1:0.9-3.5 and that of peak intensity at A1g vibration mode of spinel structure and peak intensity at F2g vibration mode is 1:0.2-0.4.