A lithium transition metal oxide electrode including an additional metal is provided herein as well electrochemical cells including the lithium transition metal oxide electrode and methods of making the lithium transition metal oxide electrode. The lithium transition metal oxide electrode includes a first electroactive material including Li.sub.1+aNi.sub.bMn.sub.cCo.sub.dM.sub.eO.sub.2, where 0.05≤a≤0.5; 0.1≤b≤0.5; 0.3≤c≤0.8; 0≤d≤0.3; 0.001 ≤e≤0.1; a+b+c+d+e=1, and M represents an additional metal, such as W, Mo, V, Zr, Nb, Ta, Fe, Al, or a combination thereof.

The present disclosure provides a cobalt-free lamellar cathode material and a method for preparing the cobalt-free lamellar cathode material, a cathode piece and a lithium ion battery. The cobalt-free lamellar cathode material comprises a LiNi.sub.xMn.sub.yO.sub.2 crystal, wherein x+y=1, 0.55≤x≤0.95, 0.05≤y≤0.45; and a lithium ion conductor, the lithium ion conductor being attached to at least part of a surface of the LiNi.sub.xMn.sub.yO.sub.2 crystal. The cobalt-free lamellar cathode material has the advantages of low cost, low surface impedance and good conductivity. Lithium ions have high diffusion velocity and electrochemical activity in the cobalt-free lamellar cathode material. A lithium ion battery manufactured by the cobalt-free lamellar cathode material has the advantages of high charge specific capacity, high discharge specific capacity, high first effect, good cycle performance and good rate capability.

Disclosed is a cathode active material for lithium secondary batteries containing lithium transition metal composite oxide in the form of primary particles having a one-body structure, the cathode active material having a ratio (R/L) of a right area (R) to a left area (L) in a particle size distribution (PSD) graph of less than 1.1, based on a maximum point of a main peak in the particle size distribution (PSD) graph, in which an X-axis represents a particle size (μm) and a Y-axis represents a relative particle amount (%).

A method for producing a positive electrode active material includes preparing a lithium transition metal oxide in the form of a secondary particle in which primary particles are aggregated, mixing the lithium transition metal oxide and a carbon-based material of a hollow structure having a plurality of pores to form a mixture, and surface treating the mixture in a mechanical manner to form a carbon coating layer on the surface of the lithium transition metal oxide, wherein the carbon-based material of a hollow structure having a plurality of pores has a specific surface area of 200 m2/g or greater and a graphitization degree(ID/IG) of 0.5 or greater.

The present invention relates to a positive active material for lithium secondary battery, its manufacturing method, and lithium secondary battery including the same, and it provides that a positive active material for lithium secondary battery, comprising: a core and a coating layer, wherein, the core is lithium metal oxide, the coating layer comprises boron, the boron compound in the coating layer comprises a lithium boron oxide and a boron oxide, the lithium boron oxide is included 70 wt % or more and 99 wt % in the entire coating layer, the lithium boron oxide comprises Li.sub.2B.sub.4O.sub.7, with respect to the lithium boron oxide 100 wt %, the content of Li.sub.2B.sub.4O.sub.7 is 55 wt % or more and 99 wt % or less.

Disclosed is a positive active material for a nonaqueous electrolyte secondary battery containing a lithium transition metal composite oxide, in which the lithium transition metal composite oxide has an α-NaFeO.sub.2 structure, a molar ratio Li/Me of Li and a transition metal (Me) of 1.05≤Li/Me≤1.4, and a porosity of 5 to 15%.

Disclosed is a positive active material for a nonaqueous electrolyte secondary battery containing a lithium transition metal composite oxide, in which the lithium transition metal composite oxide has an α-NaFeO.sub.2 structure, a molar ratio Li/Me of Li and a transition metal (Me) of 1.05≤Li/Me≤1.4, and a porosity of 5 to 15%.

A positive electrode active material for a lithium secondary battery comprising a compound represented by Chemical Formula 1 is introduced.

Li.sub.1+mNi.sub.1-w-x-y-zCo.sub.wMn.sub.xM1.sub.yM2.sub.zO.sub.2-pX.sub.p  [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.)

Provided are a lithium nickel manganese oxide composite material, a preparation method thereof and a lithium ion battery. The preparation method includes: a first calcining process is performed on a nano-oxide and a nickel-manganese precursor, to obtain an oxide-coated nickel-manganese precursor; and a second calcining process is performed on the precursor and a lithium source material, to obtain the lithium nickel manganese oxide, and a temperature of the first calcining process is lower than the second calcining process. At a lower temperature, the nano-oxide may be melted, a denser nano-oxide coating layer is formed on the surface of the precursor, so the oxide-coated nickel-manganese precursor is obtained. At a higher temperature, the nano-oxide, a nickel-manganese material and a lithium element may be more deeply combined. A problem that the nano-oxide layer is easy to fall off is solved, and cycle performance of the lithium nickel manganese oxide is greatly improved.

A positive-electrode active material precursor for a nonaqueous electrolyte secondary battery is provided that includes a nickel-cobalt-manganese carbonate composite represented by general formula Ni.sub.xCo.sub.yMn.sub.zM.sub.tCO.sub.3 (where x+y+z+t=1, 0.05≤x≤0.3, 0.1≤y≤0.4, 0.55≤z≤0.8, 0≤t≤0.1, and M denotes at least one additional element selected from a group consisting of Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, and W) and a hydrogen-containing functional group, wherein H/Me representing the ratio of the amount of hydrogen to the amount of metal components Me included in the positive-electrode active material precursor is greater than or equal to 1.60.