It is an object to achieve a resin sheet having high thermal conductance and high dielectric strength. Hexagonal boron nitride powder in accordance with an aspect of the present invention includes hexagonal boron nitride agglomerate particles each including agglomerated hexagonal boron nitride primary particles, and has a specific surface area of not less than 0.5 m.sup.2/g and not more than 5.0 m.sup.2/g. The hexagonal boron nitride primary particles each have a long diameter of not less than 0.6 μm and not more than 4.0 μm and an aspect ratio of not less than 1.5 and not more than 5.0.

A method of preparing a positive electrode active material precursor for a secondary battery includes preparing a positive electrode active material precursor by a co-precipitation reaction while adding a transition metal-containing solution containing transition metal cations, a basic solution, and an ammonium solution to a batch-type reactor, wherein a molar ratio of ammonium ions contained in the ammonium solution to the transition metal cations contained in the transition metal-containing solution added to the batch-type reactor is 0.5 or less, and a pH in the batch-type reactor is maintained at 11.2 or less.

A method of producing high strength shaped alumina by feeding alumina power into an agglomerator having a shaft with mixers able to displace the alumina power along the shaft, spraying a liquid binder onto the alumina power as it is displaced along the shaft to form a shaped alumina, and calcining the shaped alumina. The shaped alumina produced having a loose bulk density of greater than or equal to 1.20 g/ml, a surface area less than 10 m.sup.2/g, impurities of less than 5 ppm of individual metals and less than 9 ppm of impurities in total, and/or crush strength of greater than 12,000 psi.

A negative electrode material for a lithium ion battery, a negative electrode for a lithium ion battery, a lithium ion battery, a battery pack and a battery powered vehicle are disclosed herein. The negative electrode material for the lithium ion measured by means of XPS has a half-value width of 0.55-7 eV at a peak of 284-290 eV; a C/O atomic ratio of (65-75):1, and a peak area ratio of sp.sup.2C to sp.sup.3C of 1:(0.5-5) with the sum of the spectral peak areas of sp.sup.2C and sp.sup.3C being a reference. Using the negative electrode material having the structure above for the negative electrode of the lithium ion battery may provide a large lithium storage, and form a stable SEI film, thereby improving the stability of the negative electrode of the lithium during a cycling process, and improving the rate performance of the lithium ion battery.

The problem to be solved by the present invention is to provide colloidal silica for metal polishing that is capable of achieving a high polishing rate. This problem can be achieved by a colloidal silica for metal polishing, comprising a silica particle having a surface on which a functional group having at least one carboxyl group is immobilized by covalent bonding.

A positive electrode active material is provided, including a lithium transition metal oxide containing nickel (Ni), cobalt (Co), and manganese (Mn), wherein the lithium transition metal oxide has 60 mol % or more nickel (Ni) with respect the total number of moles of transition metal except lithium, and is doped with at least any one doping element selected from the group consisting of B, Zr, Mg, Ti, Sr, W, and Al. The positive electrode active material has an average particle diameter (D.sub.50) of 4 μm to 10 μm after rolling at a rolling density of 3.0 g/cm.sup.3 to 3.3 g/cm.sup.3 and has the form of a single particle. A method of preparing the positive electrode active material, a positive electrode including the positive electrode active material, and a lithium secondary battery are also provided.

A negative electrode for a secondary battery including: a negative electrode current collector; and a negative electrode active material layer present on the negative electrode current collector. The negative electrode active material layer includes a negative electrode active material, wherein the negative electrode active material for a secondary battery includes natural graphite, and has a sphericity of 0.58 to 1, a tap density of 1.08 g/cc to 1.32 g/cc, and D.sub.max−D.sub.min of 16 μm to 19 μm, wherein D.sub.max−D.sub.min is a difference between a maximum particle diameter D.sub.max and a minimum particle diameter D.sub.min in a particle size distribution.

The present invention relates to a lithium positive electrode active material for a high voltage secondary battery, where the lithium positive electrode active material comprising a spinel, and the spinel has a chemical composition of Li.sub.xNi.sub.yMn.sub.2-yO.sub.4, wherein: 0.95≤x≤1.05; and 0.43≤y≤0.47. The lithium positive electrode active material is synthesized from precursors containing Li, Ni, and Mn in a ratio Li:Ni:Mn:X:Y:2−Y, wherein: 0.95≤X≤1.05; and 0.42≤Y<0.5. The present invention also relates to a process of preparing the lithium positive electrode active material as well as a secondary battery comprising the lithium positive electrode active material.

A method for producing a metal composite hydroxide, which includes a first crystallization process of supplying a first raw material aqueous and performing a crystallization reaction and a second crystallization process of supplying a second raw material aqueous solution containing a more amount of tungsten than the first raw material aqueous solution and performing a crystallization reaction to form a tungsten-concentrated layer and in which switching of reaction atmosphere from either atmosphere of a non-oxidizing atmosphere or an oxidizing atmosphere to the other atmosphere is performed two or more times in particle growth and the time for supplying the second raw material aqueous solution into the reaction tank in the non-oxidizing atmosphere is 50% or more with respect to the entire time for supplying the second raw material aqueous solution into the reaction tank.

The present application discloses an artificial graphite, a secondary battery, a preparation method and an apparatus. The artificial graphite includes secondary particles formed by agglomeration of primary particles, the artificial graphite having a volume average particle size Dv50, denoted as A, the artificial graphite through powder compaction under a pressure of 2000 kg having a volume average particle size Dv50, denoted as B, wherein A and B satisfies: B/A≥0.85. Using the artificial graphite provided by the present application can greatly reduce the cyclic expansion of the secondary battery.