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.

Compounds, particles, and cathode active materials that can be used in lithium ion batteries are described herein. Methods of making such compounds, powders, and cathode active materials are described. The particles have a particle size distribution with a D50 ranging from 10 μm to 20 μm.

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.H.sub.2O in a mortar and then calcined at a high temperature to obtain an MOF-coated monocrystal ternary positive electrode material.

Provided herein are processes for producing positive electrode active substance particles for non-aqueous electrolyte secondary batteries which is excellent in life characteristics of a battery with respect to a repeated charging and discharging performance thereof, as well as a non-aqueous electrolyte secondary battery. In particular, provided herein are processes for producing a positive electrode active substance for non-aqueous electrolyte secondary batteries comprising lithium transition metal layered oxide having a composition represented by the formula: Li.sub.a(Ni.sub.xCo.sub.yMn.sub.1-x-y)O.sub.2 wherein a is 1.0≤a≤1.15; x is 0<x<1; and y is 0<y<1, in which the positive electrode active substance is in the form of secondary particles formed by aggregating primary particles thereof, and a coefficient of variation of a compositional ratio: Li/Me wherein Me is a sum of Ni, Co and Mn as measured on a section of the secondary particle is not more than 25%.

A sacrificial positive electrode material, a positive electrode comprising the same, and a lithium secondary battery having the positive electrode are disclosed herein. In some embodiments, a sacrificial positive electrode material includes a lithium cobalt oxide represented by the following Chemical Formula 1, wherein the sacrificial positive electrode active material has a defect formation energy of metal (M) of −4.0 to −8.5 eV, calculated using density functional theory (DFT):

Li.sub.xCo.sub.(1-y)M.sub.yO.sub.4   [Chemical Formula 1]

M is at least one selected from the group consisting of Al, Fe, Zn, Ti, W, Mg, Ge and Si, pa x and y are 5≤x≤7 and 0.05≤y≤0.6. When the defect formation energy of the metal is controlled within a specific range, a high initial charging/discharging efficiency is realized during initial charging/discharging, and the amount of gas additionally generated at the later time of charging/discharging is reduced. Thus, stability and the charging/discharging performance of a battery is improved.

A positive electrode active material that has high capacity and excellent charge and discharge cycle performance for a secondary battery is provided. A positive electrode active material that inhibits a decrease in capacity in charge and discharge cycles is provided. A high-capacity secondary battery is provided. A secondary battery with excellent charge and discharge characteristics is provided. A highly safe or reliable secondary battery is provided. A positive electrode active material contains lithium, cobalt, oxygen, and aluminum and has a crystal structure belonging to a space group R-3m when Rietveld analysis is performed on a pattern obtained by powder X-ray diffraction. In analysis by X-ray photoelectron spectroscopy, the number of aluminum atoms is less than or equal to 0.2 times the number of cobalt atoms.

A compound of formula Li.sub.4+xMnM.sup.1.sub.aM.sup.2.sub.bO.sub.c wherein: M.sup.1 is selected from the group consisting in Ni, Mn, Co, Fe and a mixture thereof; M.sup.2 is selected from the group consisting in Si, Ti, Mo, B, Al and a mixture thereof;
with: −1.2≦x≦3; 0<a≦2.5; 0≦b≦1.5; 4.3≦c≦10; and c=4+a+n.Math.b+x/2
wherein n=2 when M.sup.2 is selected from the group consisting in Si, Ti, Mo or a mixture thereof; and n=1.5 when M.sup.2 is selected from the group consisting in B, Al or a mixture thereof; and n=0 if b=0.

A positive electrode active material includes powder of composite particles including a lithium transition metal composite oxide having a lamellar rock-salt structure and a spinel phase. The spinel phase includes an oxide including lithium and at least a first element X1 selected from the group consisting of magnesium, aluminum, titanium, manganese, yttrium, zirconium, molybdenum, and tungsten, and the lithium transition metal composite oxide includes nickel or cobalt and the first element X1.

A positive electrode active material, which has higher capacity and excellent charge and discharge cycle performance, for a lithium-ion secondary battery is provided. The positive electrode active material includes lithium, cobalt, magnesium, oxygen, and fluorine; when a pattern obtained by powder X ray diffraction using a CuKα1 ray is subjected to Rietveld analysis, the positive electrode active material has a crystal structure having a space group R-3m, a lattice constant of an a-axis is greater than 2.814×10(−10th power) m and less than 2.817×10(−10th power) m, and a lattice constant of a c-axis is greater than 14.05×10(−10th power) m and less than 14.07×10(−10th power) m; and in analysis by X-ray photoelectron spectroscopy, a relative value of a magnesium concentration is higher than or equal to 1.6 and lower than or equal to 6.0 with the cobalt concentration regarded as 1.

A positive electrode active material, which has higher capacity and excellent charge and discharge cycle performance, for a lithium-ion secondary battery is provided. The positive electrode active material includes lithium, cobalt, magnesium, oxygen, and fluorine; when a pattern obtained by powder X ray diffraction using a CuKα1 ray is subjected to Rietveld analysis, the positive electrode active material has a crystal structure having a space group R-3m, a lattice constant of an a-axis is greater than 2.814×10(−10th power) m and less than 2.817×10(−10th power) m, and a lattice constant of a c-axis is greater than 14.05×10(−10th power) m and less than 14.07×10(−10th power) m; and in analysis by X-ray photoelectron spectroscopy, a relative value of a magnesium concentration is higher than or equal to 1.6 and lower than or equal to 6.0 with the cobalt concentration regarded as 1.