Surface-modified layered double hydroxides (LDHs) are disclosed, as well as processes by which they are made, and uses of the LDHs in composite materials. The surface-modified LDHs of the invention are more organophilic than their unmodified analogues, which allows the LDHs to be incorporated in a wide variety of materials, wherein the interesting functionality of LDHs may be exploited.

A precipitated silica having an SiOH.sub.isolated absorbance ratio of greater than or equal to 1.5, a silanol group density of 1 to 3.0 SiOH/nm.sup.2, a modified tapped density of 1 to 50 g/l, and a pH of 3-5, when measured as a aqueous suspension of 5.00 g of the precipitated silica in 100 ml. of deionized water allows preparation of storage-stable RTV-1 silicone rubber formulations without stabilizer. A process for preparing the precipitated silica and its use in thickening sealants is provided.

To provide a zirconia sintered body having both excellent translucency and bending strength, specifically a zirconia sintered body having both translucency and strength suitable as a denture for front tooth, and a process for its production. A translucent zirconia sintered body containing more than 4.0 mol % and at most 6.5 mol % of yttria and less than 0.1 wt % of alumina, and having a relative density of at least 99.82%, a total light transmittance of at least 37% and less than 40% to light with a wavelength of 600 nm at a thickness of 1.0 mm, and a bending strength of at least 500 MPa, and a process for its production.

An object of the present invention is to provide a non-aqueous electrolyte secondary battery which has a large charge/discharge capacity, has a small irreversible capacity, and is capable of effectively using an active material.

This object can be achieved by a material for a non-aqueous electrolyte secondary battery anode; a specific surface area determined by a BET method being not greater than 30 m.sup.2/g; an atomic ratio (H/C) of hydrogen atoms to carbon atoms determined by elemental analysis being not greater than 0.1; an average particle size being not greater than 50 μm; and a diffraction intensity ratio (R-value) determined by Equation (1) being not greater than 1.25: (wherein I.sub.max is a maximum value of a 002 diffraction intensity of carbon measured at an angle of diffraction (2θ) within a range of from 20 to 25° as determined by powder X-ray diffraction measured using CuKα rays; I.sub.min is a minimum value of a diffraction intensity measured at an angle of diffraction (2θ) within a range of from 15 to 20° as determined by powder X-ray diffraction; and 135 is a diffraction intensity at an angle of diffraction (2θ) of 35° as determined by powder X-ray diffraction).

Disclosed herein are dendritically porous three-dimensional structures, including hierarchical dendritically porous three-dimensional structures. The structures include metal foams and graphite structures, and are useful in energy storage devices as well as chemical catalysis.

The present application discloses a positive electrode active material satisfying the chemical formula L.sub.xNa.sub.yM.sub.zCu.sub.αFe.sub.βMn.sub.γO.sub.2+δ−0.5ηX.sub.η and a preparation method therefor, a sodium ion battery and an apparatus including such battery, wherein L is a doping element at alkali metal site, M is a doping element at transition metal site, and X is a doping element at oxygen site, 0≤x<0.35, 0.65≤y≤1, 0<α≤0.3, 0<β≤0.5, 0<γ≤0.5, −0.03≤δ≤0.03, 0≤η≤0.1, z+α+β+γ=1, mx+y+nz+2α+3β+4γ=2(2+δ), m is the valence state of L, and n is the valence state of M; and the pH of the positive electrode active material is 10.5-13, wherein L is a doping element at alkali metal site, M is a doping element at transition metal site, and X is a doping element at oxygen site.

A non-aqueous electrolyte secondary battery having a charge/discharge capacity, and a small irreversible capacity, which is a difference between a doping capacity and a de-doping capacity, and utilizing an active material efficiently, is provided. Such a non-aqueous electrolyte secondary battery can be provided by using a carbonaceous material for a non-aqueous electrolyte secondary battery anode of the present invention, a production method of which includes: (1) impregnating an alkali metal to a carbonaceous material precursor by adding a compound including an elemental alkali metal to obtain an alkali-impregnated carbonaceous precursor; (2) subjecting the alkali-impregnated carbonaceous precursor to heat treatment by: (a) subjecting the alkali-impregnated carbonaceous precursor to main heat treatment in a non-oxidizing gas atmosphere at a temperature from 800° C. to 1500° C.; wherein a true density is from 1.35 to 1.60 g/cm.sup.3; a specific surface area obtained by BET method using nitrogen adsorption is not greater than 30 m.sup.2/g; an average particle size is not greater than 50 μm; and an atomic ratio of hydrogen and carbon obtained by elemental analysis, H/C, is not greater than 0.1.

A carbon nanotube aggregate includes a plurality of carbon nanotubes, a metal compound added to inside and/or outside of each of the carbon nanotubes, and an oxide film that is made of an oxide of the metal compound, and covers an outer periphery of the plurality of carbon nanotubes to define an outer surface of the carbon nanotube aggregate. Since the metal compound is shielded from the atmosphere by the oxide film, separation of the metal compound and reaction of the metal compound with oxygen or water in the atmosphere are suppressed, increasing heat resistance of the carbon nanotube aggregate.

A carbon nanotube aggregate includes a plurality of carbon nanotubes, a metal compound, and an oxide of the metal compound. The metal compound is contained in a space inside of each of the carbon nanotubes and/or in a space defined between the plurality of carbon nanotubes. When the metal compound is added inside the carbon nanotube aggregate, the metal compound is oxidized by reacting with oxygen or the like during or after a production process of the CNT aggregate, and the oxide is formed in the opening of the space to which the metal compound is added, so that the metal compound is capped with the oxide. Since the metal compound inside the CNT aggregate is shielded from the atmosphere, separation of the metal compound and reaction between the metal compound and oxygen and water in the atmosphere are suppressed, increasing heat resistance of the carbon nanotube aggregate.

Methods of forming transition metal dichalcogenide aerogels are provided. Some methods include adding at least one solvent to one or more two-dimensional transition metal dichalcogenide sheets to form a transition metal dichalcogenide solution and freeze drying the transition metal dichalcogenide solution to form frozen transition metal dichalcogenide. The methods also include heating the frozen transition metal dichalcogenide to form a transition metal dichalcogenide aerogel.