The present invention relates to a lithium metal composite oxide powder having a layered structure, and comprising at least Li, Ni, and an element X, wherein: said element X is at least one element selected from the group consisting of Co, Mn, Fe, Cu, Ti. Mg, Al, W, Mo, Nb, Zn, Sn, Zr, Ga, V, B, Si, S, and P; and the lithium metal composite oxide powder satisfies requirements (1), (2), and (3): (1) an angle of difference (θ1- θ2) calculated from an angle of repose (θ1) and an angle of fall (θ2) is 15° or less, wherein the angle of repose (θ1) is an angle of slope of the lithium metal composite oxide powder piled on a measurement table, and the angle of fall (θ2) is an angle of slope measured after application of a predetermined impact force to the measurement table; (2) an average primary particle diameter is 1 .Math.m or more; and (3) an amount of water contained in the lithium metal composite oxide powder is 1000 ppm or less.

A battery includes a positive electrode including a positive electrode active material, a negative electrode, and an electrolytic solution including a nonaqueous solvent. The positive electrode active material includes a compound having a crystal structure belonging to a space group FM3-M and represented by Compositional Formula (1): Li.sub.xMe.sub.yO.sub.αF.sub.β, where, Me is one or more elements selected from the group consisting of Mn, Co, Ni, Fe, Al, B, Ce, Si, Zr, Nb, Pr, Ti, W, Ge, Mo, Sn, Bi, Cu, Mg, Ca, Ba, Sr, Y, Zn, Ga, Er, La, Sm, Yb, V, and Cr; and subscripts x, y, α, and β satisfy the following requirements: 1.7≤x≤2.2, 0.8≤y≤1.3, 1≤α≤2.5, and 0.5≤β≤2. The nonaqueous solvent includes a solvent having at least one fluoro group.

The present invention provides a method of preparing an MOF-coated monocrystal ternary positive electrode material. Firstly, a solution A of nickel, cobalt and manganese metal salts, an ammonia complexing agent solution and a caustic soda liquid are added to a reactor for reaction to obtain a precursor core; then, an organic carboxylate is dissolved in an amount of an organic solvent to obtain a solution B; the solution B and a manganese metal salt solution with a given concentration are added to the reactor and aged to obtain an MOF-coated core-shell structure precursor; the core-shell structure precursor is pre-sintered at a low temperature to obtain a nickel-cobalt-manganese oxide with monocrystal structure; the nickel-cobalt-manganese oxide with monocrystal structure is uniformly mixed with LiOH.Math.H.sub.2O in a mortar and then calcined at a high temperature to obtain an MOF-coated monocrystal ternary positive electrode material.

The present invention relates to a lithium metal composite oxide with a layered structure wherein: at least Li, Ni, and an element X are included; the element X is at least one element selected from the group consisting of Co, Mn, Mg, Ca, Sr, Ba, Zn, B, Al, Ga, Ti, Zr, Ge, Fe, Cu, Cr, V, W, Mo, Sc, Y, Nb, La, Ta, Tc, Ru, Rh, Pd, Ag, Cd, In, and Sn; and an average three-dimensional particle unevenness of primary particles with an equivalent spherical diameter of at least 1.0 μm is at least 1.91 and less than 2.9.

Particulate electrode active material with an average particle diameter in the range of from 2 to 20 μm (D50) having a general formula Li.sub.1+xTM.sub.1−xO.sub.2 wherein TM is a combination of Ni, Co and Al, and, optionally, at least one more metal selected from Mg, Ti, Zr, Nb, Ta, Mo, Mn, and W, with at least 80 mole-% of TM being Ni, and wherein x is in the range of from zero to 0.2, wherein the Co content at the outer surface of the secondary particles is higher than at the center of the secondary particles by a factor of at most 5 or by at most 30 mol-%, referring to TM.

A process for preparing a lithium nickel metal oxide is provided. The process comprises a step of high-energy milling a mixture of a nickel source, a lithium source and at least one additional metal source to form a high-energy milled intermediate, and subsequently calcining the high-energy milled intermediate to form the lithium nickel metal oxide.

Compounds that can be used as cathode active materials for lithium ion batteries are described. In some embodiments, the cathode active material includes the compound Li.sub.xNi.sub.aM.sub.bN.sub.cO.sub.2 where M is selected from Mn, Ti, Zr, Ge, Sn, Te and a combination thereof; N is selected from Mg, Be, Ca, Sr, Ba, Fe, Ni, Cu, Zn, and a combination thereof; 0.9<x<1.1; 0.7<a<1; 0<b<0.3; 0<c<0.3; and a+b+c=1. Other cathode active materials, precursors, and methods of manufacture are presented.

Provided are a nickel-based active material for a lithium secondary battery, a method of preparing the nickel-based active material, and a lithium secondary battery including a positive electrode including the nickel-based active material. The nickel-based active material includes at least one secondary particle that includes at least two primary particle structures, the primary particle structures each including a porous inner portion and an outer portion having a radially arranged structure, and the secondary particle including at least two radial centers.

A lithium-manganese composite oxide containing a lithium-iron-manganese composite oxide represented by the composition formula. Li.sub.1+x−w(Fe.sub.yNi.sub.zMn.sub.1−y−z).sub.1−xO.sub.2−δ, where 0<x<⅓, 0≤w<0.8, 0<y<1, 0<z<0.5, y+z<1, and 0≤δ<0.5, in which at least in a state of charge of a lithium ion battery using the lithium-manganese composite oxide as a positive-electrode active material, at least some of iron atoms are pentavalent.

The present invention relates to a cobalt-free positive electrode active material having improved thermal stability and electrochemical properties, and a lithium secondary battery using the same.