Modular pressurized hotbox for use and substitution in a variety of pressurized electrochemical applications to include reversible solid oxide electrolyzer and fuel cells, energy storage systems, renewable fuel production, solid-state hydrogen pumping and liquefaction, and oxygen transport membranes. This is enabled by mixed electronic and ionic conducting compositions of vanadia-yttria and vanadia-calcia stabilized zirconia and a dry powder method of manufacture for ceramic core stacks.

An object of the present invention is to provide means for releasing oxygen at a temperature lower than conventional means in an exhaust gas purification catalyst. A Ce—Zr composite oxide is provided, which has a crystallite diameter of 6.5 nm or less and a BET specific surface area of 90 m.sup.2/g or more.

A positive electrode active material includes lithium transition metal-containing composite oxide particles containing an additive element M1 and includes a coating layer formed of a metal composite oxide of Li and a metal element M2 on a part of a surface of the particles. The particles have a d50 of 3.0 to 7.0 μm, a BET specific surface area of 2.0 to 5.0 m.sup.2/g, a tap density of 1.0 to 2.0 g/cm.sup.3, and an oil absorption amount of 30 to 60 ml/100 g. For each of a plurality of primary particles having a primary particle size within a range of 0.1 to 1.0 μm among the primary particles, a coefficient of variation of the concentration of M1 is 1.5 or less, and the amount of M2 is 0.1 to 1.5 atom % with respect to the total number of atoms of Ni, Mn, and Co contained in the composite oxide particles.

The present invention relates to a method of quickly preparing a large amount of octacalcium phosphate and octacalcium phosphate prepared thereby. A method of preparing octacalcium phosphate according to an embodiment of the present invention includes preparing a calcium phosphate solution, controlling an initial pH by controlling a pH of the calcium phosphate solution to a range from 5 to 6 using an acidic solution at a time point at which the pH of the calcium phosphate solution increases, heating the calcium phosphate solution to a temperature ranging from 60° C. to 90° C., and controlling a terminal pH by controlling the pH of the calcium phosphate solution to a range from 5 to 6 using a basic solution at a time point at which the pH of the heated calcium phosphate solution decreases.

Systems and methods are disclosed for a rock-salt structure formed from an electrochemically-driven amorphous-to-crystalline (a-to-c) transformation of nanostructured Nb.sub.2O.sub.5, the rock-salt structure including, upon cycling with lithium ions (Li+), an insertion of lithium ions (Li+) into Nb.sub.2O.sub.5 to form the rock-salt structure (RS—Nb.sub.2O.sub.5).

An iron oxide powder includes a porous structure having the diameter of from 0.3 μm to 2 μm, wherein the iron oxide powder has an aluminum content of from 10 mol % to 80 mol %.

The present disclosure provides for compositions, methods of making compositions, and methods of using the composition. In an aspect, the composition can be a reactive material that can be used to split a gas such as water or carbon dioxide.

The invention relates to a strontium aluminate mixed oxide precursor and a method for producing same, as well as to a strontium aluminate mixed oxide and method for producing same. The strontium aluminate mixed oxide precursor can be transformed into a strontium aluminate mixed oxide at relatively low temperature. The strontium aluminate mixed oxide is characterized by substantially spherically-shaped particles with a spongy- or porous bone-like microstructure. A luminescent material including a strontium aluminate mixed oxide is also provided.

A lithium vanadium oxide crystal and usage thereof that can achieve further excellent electrochemical characteristics are provided. New lithium vanadium oxide crystal is a lithium vanadium oxide crystal which is Li.sub.3VO.sub.4 to which tetravalent metal species M is doped, in which the lithium vanadium oxide crystal is represented by a chemical formula of Li.sub.3+1V.sub.1−xM.sub.xO.sub.4 and includes only a single crystal structure with γ-phase as Li.sub.3VO.sub.4 under a temperature environment including normal temperature, and the tetravalent metal species M is included in a ratio of x≥0.2.

The present invention relates to a cathode active material, and a lithium secondary battery comprising the same, the present invention provides a cathode active material, represented by the following Chemical Formula 1, wherein I003/I104 ratio is 1.6 or more, and R-factor value represented by the following Formula 1 is 0.40 to 0.44, and c-axis lattice constant (c) and a-axis lattice constant (a) satisfy 3(a)+5.555≤(c)≤3(a)+5.580:
R-factor=(I102+I006)/(I101)  Formula 1 wherein I003, I006, I101, I102, and I104 are the intensity of diffraction peaks on the (003), (006), (101), (102), and (104) planes by X-ray diffraction analysis using CuKα-rays,
Li.sub.α[(Ni.sub.xCo.sub.y).sub.1-βA.sub.β]O.sub.z  Chemical Formula 1 in the Chemical Formula 1, 0.95≤α≤1.1, 0.75≤x≤0.95, 0.03≤y≤0.25, 0<β≤0.2, and 1.9≤z≤2.1, and A is a dopant metal element, and the average oxidation number N of A is 3.05≤N≤3.35.