Provided are a nickel-manganese composite hydroxide capable of producing a secondary battery having a high particle fillability and excellent battery characteristics when used as a precursor of a positive electrode active material and a method for producing the same. A nickel-manganese composite hydroxide is represented by General Formula: Ni.sub.xMn.sub.yM.sub.z(OH).sub.2+α and contains a secondary particle formed of a plurality of flocculated primary particles. The primary particles have an aspect ratio of at least 3, and at least some of the primary particles are disposed radially from a central part of the secondary particle toward an outer circumference thereof. The secondary particle has a ratio I(101)/I(001) of a diffraction peak intensity I(101) of a 101 plane to a peak intensity I(001) of a 001 plane, measured by an X-ray diffraction measurement, of up to 0.15.

The present invention relates to aggregated boron nitride particles including hexagonal boron nitride primary particles aggregated, having a specific surface area measured by the BET method of 2 to 6 m.sup.2/g and a crushing strength of 5 MPa or more. The thermally conductive resin composition of the present invention includes the aggregated boron nitride particles of the present invention. The heat dissipation member of the present invention includes the thermally conductive resin composition of the present invention. According to the present invention, aggregated boron nitride particles that can suppress the formation of voids in a heat dissipation member and can improve the insulation breakdown characteristics and the thermal conductivity of a heat dissipation member, a thermally conductive resin composition including the aggregated boron nitride particles, and a heat dissipation member using the thermally conductive resin composition can be provided.

A nickel-based active material precursor for a lithium secondary battery includes: a secondary particle including a plurality of particulate structures, wherein each particulate structure includes a porous core portion and a shell portion, the shell portion including primary particles radially arranged on the porous core portion; and the secondary particle has a plurality of radial centers. When the nickel-based active material precursor is used, a nickel-based positive active material having a short lithium ion diffusion distance, in which intercalation and deintercalation of lithium are facilitated, may be obtained. A lithium secondary battery manufactured using the positive active material may exhibit enhanced lithium availability, and may exhibit enhanced capacity and lifespan due to suppression of crack formation in the active material during charging and discharging.

The present disclosure provides an apparatus capable of continuously producing carbon nanotubes having high crystallinity, a low residual catalyst content and a high aspect ratio. The apparatus for producing carbon nanotubes includes: a reaction unit configured to synthesize carbon nanotubes (CNTs), a supply unit configured to supply a carbon source to the reaction unit through a supply pipe; and a collection unit configured to collect carbon nanotubes discharged from the reaction unit, wherein the reaction unit may include a chemical vapor deposition reactor.

A powder of melted particles, more than 95% by number of the particles exhibiting a circularity of greater than or equal to 0.85. The powder including more than 99.8% of a rare earth metal oxide and/or of hafnium oxide and/or of an aluminum oxide, as percentage by mass based on the oxides. The powder has a median particle size D.sub.50 of less than 15 μm, a 90 percentile of the particle sizes, D.sub.90, of less than 30 μm, and a size dispersion index (D.sub.90−D.sub.10)/D.sub.10 of less than 2, and a relative density of greater than 90%. The D.sub.n percentiles of the powder are the particle sizes corresponding to the percentages, by number, of n %, on the cumulative distribution curve of the size of the particles in the powder and the particle sizes are classified by increasing order.

The titanium phosphate powder of the present invention includes plate-shaped crystalline particles of titanium phosphate, an average thickness of the plate-shaped crystalline particles is 0.01 μm or more and less than 0.10 μm, and an aspect ratio, which is a value obtained by dividing an average primary particle diameter of the plate-shaped crystalline particles by the average thickness, is 5 or more. In the method for producing a titanium phosphate powder of the present invention, a raw material containing titanium and phosphorus is caused to react by a hydrothermal synthesis method, and when the titanium phosphate powder including plate-shaped crystalline particles of titanium phosphate is produced, a mixture of titanium sulfate and phosphoric acid is used as the raw material.

Method of producing short carbon nanotube fibers from a carbonaceous gas.

The present invention relates to a positive electrode active material comprising a secondary particle formed of agglomerates of a plurality of primary particles, wherein each primary particle comprises a first primary particle constituting a core portion of the secondary particle, and a second primary particle provided so as to surround the first primary particle and constituting a shell portion of the secondary particle. In particular, the first primary particle consists of a1 and a2, wherein the a1 is the average length of the major axis of the first primary particle, and the a2 is the average length of the minor axis perpendicular to the a1, wherein the a1 is equal to or greater than the a2. In addition, the second primary particle consists of b1 and b2, wherein the b1 is an average length of the major axis of the second primary particle, and b2 is an average length of the minor axis perpendicular to the b1, wherein the b1 is greater than b2, and the ratio (b1/b2) of the b1 to b2 is 1 to 25.

An aluminum nitride particle including: a plurality of planes randomly arranged in a surface of the particle, the plurality of planes forming an obtuse ridge part or an obtuse valley part in the surface of the particle, the plurality of planes being observable in a scanning electron micrograph with 500 times magnification; wherein the particle has a longer diameter L of 20 to 200 μm; a ratio L/D of the longer diameter L (unit: μm) to a shorter diameter D (unit: μm) of the particle is 1 to 1.25; and the plurality of planes comprise a first plane, wherein an area S (unit: μm.sup.2) of the first plane satisfies S/L≥1.0 μm.

A method for producing silicon-containing oxide-coated aluminum nitride particles including aluminum nitride particles and a silicon-containing oxide coating covering a surface of each of the aluminum nitride particles. The method includes a first step including mixing aluminum nitride particles and an organic silicone compound solution in which an organic silicone compound containing a specific structure is dissolved in a solvent to form a mixture and then heating the mixture to remove the solvent and to obtain aluminum nitride particles coated with the organic silicone compound; and a second step including heating the aluminum nitride particles coated with the organic silicone compound at a temperature of 300° C. or more and 1,000° C. or less.