This application discloses a positive electrode active material and a preparation method thereof, a positive electrode plate, a lithium-ion secondary battery, and a battery module, battery pack and apparatus related thereto. The positive electrode active material includes secondary particles formed by agglomeration of primary particles, where the primary particles are a lithium transition metal oxide, and a transition metal site of the lithium transition metal oxide includes nickel and a doping element; and a Young's modulus E of the primary particles satisfies 175 GPa≤E≤220 GPa.

A positive electrode active material and a preparation method thereof, a positive electrode plate, a lithium-ion secondary battery, and a battery module, a battery pack, and apparatus containing the lithium-ion secondary battery are provided. The positive electrode active material includes secondary particles formed by agglomeration of primary particles, where the primary particles include a layered nickel-containing lithium composite oxide, and the nickel-containing lithium composite oxide includes a doping element; and when the positive electrode active material is charged from an 11% delithiated state to a 78% delithiated state at a rate of 0.1C, a lattice of the primary particles has a maximum shrinkage rate satisfying Δa.sub.max≤3.00% in an a-axis direction, and a maximum swelling rate satisfying Δc.sub.max≤3.02% in a c-axis direction.

A positive electrode active material and a preparation method thereof, a positive electrode plate, a lithium-ion secondary battery, and a battery module, battery pack, and apparatus containing such lithium-ion secondary battery are provided. The positive electrode active material includes matrix particles and a coating layer covering an exterior surface of the matrix particle, where the matrix particle includes a lithium nickel cobalt manganese oxide, and the coating layer includes an oxide of element M.sup.1; the matrix particle is doped with element M.sup.2 and element M.sup.3, element M.sup.2 in the matrix particle is uniformly distributed, and element M.sup.3 in the matrix particle has a decreasing concentration from the exterior surface to a core of the matrix particle; and element M.sup.1 and element M.sup.3 are each independently selected from one or more of Mg, Al, Ca, Ba, Ti, Zr, Zn, and B, and element M.sup.2 includes one or more of Si, Ti, Cr, Mo, V, Ge, Se, Zr, Nb, Ru, Rh, Pd, Sb, Te, Ce, and W.

The present application discloses a positive electrode active material including a lithium nickel cobalt manganese oxide, the molar content of nickel in the lithium nickel cobalt manganese oxide accounts for 60%-90% of the total molar content of nickel, cobalt and manganese, and the lithium nickel cobalt manganese oxide has a layered crystal structure of a space group R3m; a transition metal layer of the lithium nickel cobalt manganese oxide includes a doping element, and the local mass concentration of the doping element in particles of the positive electrode active material has a relative deviation of 20% or less; and in a differential scanning calorimetry spectrum of the positive electrode active material in a 78% delithiation state, an initial exothermic temperature of a main exothermic peak is 200° C. or more, and an integral area of the main exothermic peak is 100 J/g or less.

Provided is a thermal spraying material capable of forming a thermally sprayed coating film having improved plasma erosion resistance. The invention disclosed here provides a thermal spraying material. This thermal spraying material comprises composite particles in which a plurality of yttrium fluoride microparticles are integrated. In addition, the compressive strength of the composite particles is 5 MPa or more.

The purpose of the present invention is to provide a zirconia-based composite oxide for making it possible to form a catalyst layer which, despite having a reduced thickness, has a sufficient quantity of catalyst to function in exhaust gas treatment on a wall of a honeycomb structure. The purpose of the present invention is also to provide a method for manufacturing said zirconia-based composite oxide. The present invention relates to a zirconia-based composite oxide characterized in that the tap bulk density thereof is 0.75 g/mL or greater, and the specific surface area thereof after heat treatment for three hours at 1000° C. is 45 m.sup.2/g or greater.

A positive electrode active material and a preparation method thereof, a positive electrode plate, a lithium-ion secondary battery, and a battery module, battery pack, and apparatus containing such lithium-ion secondary battery are disclosed. The positive electrode active material includes a lithium nickel cobalt manganese oxide. In the lithium nickel cobalt manganese oxide, the number of moles of nickel accounts for 50% to 95% of the total number of moles of nickel, cobalt, and manganese. The lithium nickel cobalt manganese oxide has a layered crystal structure with a space group R3m. The lithium nickel cobalt manganese oxide includes a doping element. When the positive electrode active material is in a 78% delithiated state, the doping element has two or more different valence states, and the amount of doping element in a highest valence state accounts for 40% to 90% of the total amount of doping element.

This application discloses a positive electrode active material, including bulk particles and a coating layer applied on an exterior surface of each of the bulk particles, where the bulk particle includes a lithium composite oxide that contains element nickel and a doping element M.sup.1, and the coating layer includes an oxide of element M.sup.2. When the positive electrode active material is in a 11% delithiated state, average valences of element M.sup.1 and M.sup.2 are α.sup.1 and β.sup.1, respectively; when the positive electrode active material is in a 78% delithiated state, average valences of element M.sup.1 and M.sup.2 are α.sup.2 and β.sup.2, respectively; and α.sup.2>α.sup.1, β.sup.1=β.sup.2. Element M.sup.1 includes one or more of Si, Ti, Cr, Mo, V, Se, Nb, Ru, Rh, Pd, Sb, Te, Ce, and W, and element M.sup.2 is selected from one or more of Mg, Al, Ca, Zr, Zn, Y, and B.

Described herein are low or no-cobalt materials useful as electrode active materials in a cathode for lithium or lithium-ion batteries. For example, compositions of matter are described herein, such as electrode active materials that can be incorporated into an electrode, such as a cathode. The disclosed electrode active materials exhibit high specific energy and voltage, and can also exhibit high rate capability and/or long operational lifetime.

Various lithium cobalt oxides materials doped with one or more metal dopants having a chemical formula of Li.sub.x Co.sub.y O.sub.z (doped Me1.sub.a Me2.sub.b Me3.sub.c . . . MeN.sub.n), and method and apparatus of producing the various lithium cobalt oxides materials are provided. The method includes adjusting a molar ratio M.sub.LiSalt:M.sub.CoSalt:M.sub.Me1Salt:M.sub.Me2Salt:M.sub.Me3Salt: . . . M.sub.MeNSalt of a lithium-containing salt, a cobalt-containing salt and one or more metal-dopant-containing salts within a liquid mixture to be equivalent to a ratio of x:y:a:b:c: . . . n, drying a mist of the liquid mixture in the presence of a gas to form a gas-solid mixture, separating the gas-solid mixture into one or more solid particles of an oxide material, and annealing the solid particles of the oxide material in the presence of another gas flow to obtain crystalized particles of the lithium cobalt oxide material. The process system has a mist generator, a drying chamber, one or more gas-solid separator, and one or more reactors.