A cathode material, containing a crystal with a superlattice structure, is provided. A chemical formula of the crystal is xLi.sub.2MO.sub.3.(1-x)LiNi.sub.aCo.sub.bMn.sub.(1-a-b)O.sub.2, where 0<x≤0.1, 0.8≤a<1, b≤0.1, and M is selected from one or more of Mn, Co, and Ni. A preparation method of the cathode material and a battery or a capacitor containing the cathode material are also provided.

A gradient doped cobalt-free positive electrode material and a preparation method therefor, a lithium-ion battery positive electrode, and a lithium battery. The positive electrode material consists of LiNi.sub.xMn.sub.yA.sub.zO.sub.2. The content of element A in the positive electrode material decreases in a direction from a surface layer of the positive electrode material to the center, and A is one or more of Al, Zr, Ti, B, and W. The preparation method is easy to implement, simplifies roasting condition requirements, and provides a cobalt-free positive electrode material having good cycle performance.

A cobalt-free positive electrode material and a preparation method therefor, a lithium ion battery positive electrode, and a lithium ion battery, relating to the technical field of lithium ion batteries. The positive electrode material comprises a core and a shell covering the core, the core being a cobalt-free positive electrode material, the chemical formula of the core being LiNi.sub.xMn.sub.yO.sub.2, wherein 0.55≤x≤0.95 and 0.05≤y≤0.45, and the shell is a coating agent and carbon. The present method can improve the dispersibility of the cobalt-free positive electrode material during the coating process, and can also improve the conductivity of the cobalt-free positive electrode material.

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 method includes a delithiation step of deintercalating a part of lithium of a Li-rich metal oxide represented by [Formula 1] below and having a layered structure, and a heat-treatment step of heat-treating the delithiated Li-rich metal oxide, thereby allowing dispersion to be achieved through diffusion of M′ and/or M elements constituting the Li-rich metal oxide:

a{Li.sub.2M′O.sub.3}.Math.(1−a){LiMO.sub.2} or Li.sub.1+x(M′M).sub.1−xO.sub.2  [Formula 1]

(wherein 0<a<1.0, M′ and M are one or more selected from 3d, 4d, 5d transition metals or non-transition metals including Al, Mg, Mn, Ni, Co, Cr, V and Fe, and satisfy electrical neutrality according to the type and oxidation number of M′ and M and an amount of lithium in a layered structure of a material.

The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a positive electrode active material which includes a lithium-rich lithium manganese-based oxide containing at least lithium, nickel, manganese and molybdenum, wherein the lithium manganese-based oxide includes at least one primary particle and a molybdenum-containing flux is used to improve the crystal growth of the primary particle, resulting in mitigation and/or prevention of a decrease in stability caused by lithium and manganese present in excessive amounts in the lithium manganese-based oxide, and a lithium secondary battery including the same.

The present invention relates to a positive electrode active material, wherein the positive electrode active material is a lithium transition metal oxide including a first doping element (A) and a second doping element (B), wherein the first doping element is one or more selected from the group consisting of Zr, La, Ce, Nb, Gd, Y, Sc, Ge, Ba, Sn, Sr, Cr, Mg, Sb, Bi, Zn, and Yb, the second doping element is one or more selected from the group consisting of Al, Ta, Mn, Se, Be, As, Mo, V, W, Si, and Co, and a weight ratio (A/B ratio) of the first doping element to the second doping element is 0.5 to 5.

In one embodiment, the present disclosure relates to a method of preparing a positive electrode active material, which includes mixing a nickel cobalt manganese hydroxide precursor containing nickel in an amount of 60 mol % or more based on a total number of moles of transition metals in the precursor, a lithium-containing raw material, and a doping raw material represented by Formula 2 (set forth herein), and sintering the mixture to prepare a positive electrode active material represented by Formula 1 (set forth herein).