A device comprising a nonlinear optical (NLO) material according to the formula XLi.sub.2Al.sub.4B.sub.6O.sub.20F. A device comprising a nonlinear optical material (NLO) according to the formula KSrCO.sub.3F, wherein the NLO comprises at least one single crystal. A nonlinear optical material selected from the group consisting of KSrCO.sub.3F Rb.sub.3Ba.sub.3Li.sub.2Al.sub.4B.sub.6O.sub.20F and K.sub.3Sr.sub.3Li.sub.2Al.sub.4B.sub.6O.sub.20F.

The present invention relates to a lithium composite metal oxide which satisfies the requirements (1) and (2) described below. Requirement (1): The ratio of the half width A of the diffraction peak within the range of 2θ=64.5±1° to the half width B of the diffraction peak within the range of 2θ=44.4±1°, namely A/B is from 1.39 to 1.75 (inclusive) in powder X-ray diffractometry using a Cu-Kα ray. Requirement (2): The ratio of the volume-based 90% cumulative particle size (D.sub.90) to the volume-based 10% cumulative particle size (D.sub.10), namely D.sub.90/D.sub.10 is 3 or more.

Multi-layered graphene materials and methods of making and use are described herein. A multi-layered graphene material can include a plurality of graphene layers having a plurality of intercalated nano- or microstructures that form a plurality of yolk/shell type structures. Each yolk/shell type structure can include at least two graphene layers that form a shell-like structure that encompasses a void space having at least one of the plurality of nano- or microstructures. The void space has a volume sufficient to allow for volume expansion of the at least one of the plurality of nano- or microstructures without deforming the shell-like structure.

A thermal interface material for transferring heat by interposing between two materials may include a graphite film. The graphite film may have a thickness of 1 μm to 50 μm, a density of 1.40 g/cm.sup.3 to 2.26 g/cm.sup.3, a thermal conductivity of 500 W/mK to 2000 W/mK in a film plane direction, and an arithmetic average roughness Ra of 0.1 μm to 10 μm on a surface of the graphite film.

A method of manufacturing a conversion element is disclosed. A precursor material is selected from one or more of lutetium, aluminum and a rare-earth element. The precursor material is mixed with a binder and a solvent to obtain a slurry. A green body is formed from the slurry and the green body is sintered to obtain the conversion element. The sintering is performed at a temperature of more than 1720° C.

A positive electrode active material for a nonaqueous electrolyte secondary battery includes particles of a lithium-transition metal composite oxide that contains nickel in the composition thereof and has a layered structure. The particles have an average particle size D.sub.SEM based on electron microscopic observation in a range of 1 μm to 7 μm in which a ratio D.sub.50/D.sub.SEM of a 50% particle size D.sub.50 in volume-based cumulative particle size distribution to the average particle size based on electron microscopic observation is in a range of 1 to 4, and a ratio D.sub.90/D.sub.10 of a 90% particle size D.sub.90 to a 10% particle size D.sub.10 in volume-based cumulative particle size distribution is 4 or less.

Disclosed is a cathode active material for secondary batteries comprising one or more compounds having a layered-crystal structure, represented by the following Formula 1, wherein a transition metal layer contains Li, in an amount lower than 20%, based on a total amount of a transition metal site, and a ratio of Ni positioned in a lithium layer, that is, a cation mixing ratio is 1% to 4.5%, based on a total amount of a lithium site in the lithium layer to stably support the layered-crystal structure: (1-s-t)[Li(Li.sub.aMn.sub.(1-a-x-y)Ni.sub.xCo.sub.y)O.sub.2]*s[Li.sub.2CO.sub.3]*t[LiOH] (1), wherein 0<a<0.2; 0<x<0.9; 0<y<0.5; a+x+y<1; 0<s<0.03; and 0<t<0.03. The cathode active material exhibits long lifespan and superior stability at room temperature and high temperatures in spite of repeated charge and discharge at a high current.

Single crystals of a new noncentrosymmetric polar oxysulfide SrZn.sub.2S.sub.2O (s.g. Pmn2.sub.1) grown in a eutectic KF-KCl flux with unusual wurtzite-like slabs consisting of close-packed corrugated double layers of ZnS.sub.3O tetrahedra vertically separated from each other by Sr atoms and methods of making same.

A method for configuring a non-lithium-intercalation electrode includes intercalating an insertion species between multiple layers of a stacked or layered electrode material. The method forms an electrode architecture with increased interlayer spacing for non-lithium metal ion migration. A laminate electrode material is constructed such that pillaring agents are intercalated between multiple layers of the stacked electrode material and installed in a battery.

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.