Abstract: A positive electrode active material for a lithium secondary battery comprising a compound represented by Chemical Formula 1 is introduced. Li1+mNi1-w-x-y-zCowMnxM1yM2zO2-pXp??[Chemical Formula 1] (In the Chemical Formula 1, M1 and M2 are different from each other, and any one element selected from the group consisting of Al, Mg, Zr, Sn, Ca, Ge, Ti, Cr, Fe, Zn, Y, Ba, La, Ce, Sm, Gd, Yb, Sr, Cu and Ga respectively, X is any one element selected from the group consisting of F, N, S, and P, w, x, y, z, p and m are respectively 0.125<w<0.202, 0.153<x<0.225, 0?y?0.1, 0?z?0.1, 0.34?w+x?0.36, 0?p?0.1, and ?0.1?m?0.2.

Abstract: The present disclosure relates to a positive active material for a lithium rechargeable battery and a lithium rechargeable battery including the same, which include a first compound represented by Chemical Formula 1 and a second compound represented by Chemical Formula 2, and a content of the first compound is 65 wt % or more based of the positive active material of 100 wt %. Lia1Nib1Coc1Mnd1M1e1M2f1O2-f1 ??[Chemical Formula 1] Lia2Nib2Coc2Mnd2M3e2M4f2O2-f2 ??[Chemical Formula 2] Chemical Composition 1 and 2 of each composition and molar ratio is as defined in the specification. Each composition and molar ratio of Chemical Formula 1 and 2 is as defined in the specification.

Abstract: An austenitic high manganese steel having superior formability, strengths and weldability, and a process for manufacturing the steel, are disclosed. The superior formability of the steel is suitable for use on automobiles and electronic panel. The steel has a composition of (in weight %) less than 1.5% of C, 15.0-35.0% of Mn, 0.1-6.0% of Al, and the balance of Fe and other indispensable impurities. The size of the austenite grains is less than 40.0 .mu.m, and, one or more elements are added by selecting them from a group consisting of less than 0.60% of Si, less than 5.0% of Cu, less than 1.0% of Nb, less than 0.5% of V, less than 0.5% of Ti, less than 9.0% of Cr, less than 4.0% of Ni, and less than 0.2% of N, thereby providing an austenitic high manganese steel having superior formability, strengths and weldability.