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 containing such lithium-ion secondary battery. The positive electrode active material includes bulk particles and an element M.sup.1-containing oxide coating layer applied on an exterior surface of each of the bulk particles. The bulk particle includes a nickel-containing lithium composite oxide. Bulk phases of the bulk particles are uniformly doped with element M.sup.2. A surface layer of the bulk particle is an exterior doped layer doped with element M.sup.3. Element M.sup.1 and element M.sup.3 are each independently selected from one or more of Mg, Al, Ca, Ce, Ti, Zr, Zn, Y, 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.

One aspect of the present disclosure provides a hexagonal boron nitride powder having a purity of 98 mass % or more and a specific surface area of less than 2.0 m.sup.2/g.

The present invention is directed to a method for producing a silicon nitride sintered material, the method including heating a molded article, which contains a silicon nitride powder having a β phase ratio of 80% or more, a dissolved oxygen content of 0.2% by mass or less, and a specific surface area of 5 to 20 m.sup.2/g, and a sintering auxiliary containing a compound having no oxygen bond, and which has an overall oxygen content controlled to be 1 to 15% by mass and an aluminum element overall content controlled to be 800 ppm or less, to a temperature of 1,200 to 1,800° C. in an inert gas atmosphere under a pressure of 0 MPa.Math.G or more and less than 0.1 MPa.Math.G to sinter the silicon nitride.

In the present invention, there can be provided a method for producing a silicon nitride sintered material, which method is advantageous in that a silicon nitride sintered material having high thermal conductivity can be obtained even when using a silicon nitride powder having a high β phase ratio and conducting calcination under normal pressure or substantially normal pressure.

The present invention relates to a lubricant containing molybdenum sulfide particles, and the molybdenum sulfide particles contain molybdenum disulfide having a 3R crystal structure. The present invention relates to a lubricating composition containing molybdenum sulfide particles, which are the lubricant, and a base oil which is a mineral oil, a synthetic oil, or a partially synthetic oil.

A positive electrode active material precursor, a method of preparing the same, and a positive electrode active material, a positive electrode, and a lithium secondary battery prepared from the same. In some embodiments, a positive electrode active material precursor includes nickel, cobalt, and manganese, wherein the positive electrode active material precursor satisfies: Equation 1 (2.5≤C.sub.(100)/C.sub.(001)≤5.0) and Equation 2 (1.0≤C.sub.(101)/C.sub.(001)≤3.0), where C.sub.(001) is a crystalline size in a (001) plane, C.sub.(100) is a crystalline size in a (100) plane, and C.sub.(101) is a crystalline size in a (101) plane. The positive electrode active material precursor has particle growth of a (001) plane that is suppressed.

The present invention relates to a process for preparing a surface treated filler material product with succinic anhydride(s), a surface treated filler material product, a polymer composition, a fiber and/or filament and/or film and/or thread comprising the surface treated filler material product and/or the polymer composition, an article comprising the surface treated filler material product and/or the polymer composition and/or the fiber and/or filament and/or film and/or thread as well as the use of a mono-substituted succinic anhydride for decreasing the hydrophilicity of a calcium carbonate-containing filler material surface and the use of a surface-treated filler material product for initiating the crosslinking reaction in epoxide resins.

Preparation, characterization, and an electrochemical study of Mg.sub.0.1V.sub.2O.sub.5 prepared by a novel sol-gel method with no high-temperature post-processing are disclosed. Cyclic voltammetry showed the material to be quasi-reversible, with improved kinetics in an acetonitrile-, relative to a carbonate-, based electrolyte. Galvanostatic test data under a C/10 discharge showed a delivered capacity >250 mAh/g over several cycles. Based on these results, a magnesium anode battery, as disclosed, would yield an average operating voltage ˜3.2 Volts with an energy density ˜800 mWh/g for the cathode material, making the newly synthesized material a viable cathode material for secondary magnesium batteries.

A positive electrode active material for lithium secondary batteries includes a lithium composite metal compound containing secondary particles that are aggregates of primary particles which are capable of being doped or dedoped with lithium ions and satisfies all of specific requirements (1) to (4).

A method of making a purified precipitated calcium carbonate from lime mud can include admixing a lime mud cake with water and sodium carbonate to form a first slurry; heating the first slurry under conditions to age the slurry and form one or more of pirssonite, shortite, and gaylussite; separating a solid portion from the aged slurry; washing the solid portion under conditions sufficient to decompose the one or more of pirssonite, shortite, and gaylussite to a CaCO.sub.3 solid fraction and Na.sub.2CO.sub.3 solid fraction and to remove sodium salts; and admixing the CaCO.sub.3 solid fraction with water and a dispersant to disperse the CaCO.sub.3 solid fraction in water and form a dispersed slurry having a Brookfield viscosity of less than about 1000 cps at 100 rpm, thereby producing a dispersed slurry containing the purified precipitated calcium carbonate.

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.