This positive electrode active material is for a secondary battery and contains a lithium transition metal complex oxide. The lithium transition metal complex oxide is represented by general formula Li.sub.xMn.sub.yNi.sub.zSb.sub.aO.sub.bF.sub.c (x+y+z+a≤b+c=2, 1≤x≤1.2, 0.4≤y≤0.8, 0≤z≤0.4, 0<a<0.01, and 1.8<b<2 are satisfied) and does not include Co.

A process for producing a material in the form of nanosheets by ball milling of crystals of the material, wherein the ball milling takes place in the presence of a reactive gas.

A thin film structure including a dielectric material layer and an electronic device to which the thin film structure is applied are provided. The dielectric material layer includes a compound expressed by ABO.sub.3, wherein at least one of A and B in ABO.sub.3 is substituted and doped with another atom having a larger atom radius, and ABO.sub.3 becomes A.sub.1-xA′.sub.xB.sub.1-yB′.sub.yO.sub.3 (where x>=0, y>=0, at least one of x and y≠0, a dopant A′ has an atom radius greater than A and/or a dopant B′ has an atom radius greater than B) through substitution and doping. A dielectric material property of the dielectric material layer varies according to a type of a substituted and doped dopant and a substitution doping concentration.

A process for producing a surface-modified particulate lithium nickel metal oxide material is provided. The process comprises the dry mixing lithium nickel metal oxide particles with at least one metal-containing compound using acoustic energy and then calcining the mixture at a temperature of less than or equal to 800 # C.

Provided is a particulate phosphor including a single crystal having a composition represented by a compositional formula (Y.sub.1-x-y-zLu.sub.xGd.sub.yCe.sub.z).sub.3+aAl.sub.5−aO.sub.12 (0≤x≤0.9994, 0≤y≤0.0669, 0.001≤z≤0.004, −0.016≤a≤0.315) and a particle diameter (D50) of not less than 20 μm. Also provided is a light-emitting device including a phosphor-including member that includes the phosphor and a sealing member including a transparent inorganic material sealing the phosphor or a binder including an inorganic material binding particles of the phosphor, and a light-emitting element that emits a blue light for exciting the phosphor.

This application provides a positive active material and a preparation method thereof, an electrochemical battery, a battery module, a battery pack, and an apparatus. The positive active material includes an inner core and a coating layer, where the coating layer coats a surface of the inner core. The inner core is selected from a ternary material with a molecular formula of Li.sub.1+a[Ni.sub.xCo.sub.yMn.sub.zM.sub.bM′.sub.c]O.sub.2−dY.sub.d, where distribution of each of the doping elements M, M′, and Y in the inner core meets the following condition: there is a reduced mass concentration gradient from an outer side of the inner core to a center of the inner core. The positive active material herein features high gram capacity, high structural stability, and high thermal stability, so that the electrochemical battery has excellent cycle performance and storage performance and high initial discharge gram capacity.

To provide a dielectric composition having excellent reliability. The dielectric composition contains a main component represented by a composition formula (Sr.sub.1-xCa.sub.x).sub.m(Ti.sub.1-yHf.sub.y)O.sub.3-δN.sub.δ, in which 0.15<x≤0.90, 0<y≤0.15, 0.90≤m≤1.15, 0<δ≤0.05 are satisfied.

The present disclosure discloses a lithium-manganese rich material and a preparation method and a use thereof.

The present disclosure provides a cobalt-free cathode material of a lithium ion battery, a method for preparing the cobalt-free cathode material, and the lithium ion battery. A general formula of the cobalt-free cathode material is Li.sub.xNi.sub.aMn.sub.bR.sub.cO.sub.2, wherein, 1≤x≤1.15, 0.5≤a≤0.95, 0.02≤b≤0.48, 0<c≤0.05, and R is aluminum or tungsten. Therefore, as the cobalt-free cathode material is free of metal cobalt, the cost of the cathode material can be lowered effectively. Aluminum or tungsten in the cobalt-free cathode material can stabilize a crystal structure of the cathode material better, such that the lithium ion battery has excellent rate capability and cycle performance, and furthermore, good cycling stability of the lithium ion battery can be still maintained under a high-temperature and high-pressure testing condition.

The present invention belongs to the technical field of inorganic luminescent materials, particularly relates to a nitride fluorescent material, and further discloses a light-emitting device containing such a fluorescent material. The nitride fluorescent material contains a compound with a structure like M.sub.mAl.sub.xSi.sub.yN.sub.3: aR, bEu, cCe. The fluorescent material has very high physical stability and chemical stability, and the fluorescent material is better in crystallization, and thus has relatively high external quantum efficiency. When being applied to a light-emitting device, the fluorescent material can fully exert the advantages of good stability and high external quantum efficiency, and the light-emitting efficiency and stability of the light-emitting device can be further improved.