A positive electrode active material includes a lithium-rich lithium manganese-based oxide, wherein the lithium-rich lithium manganese-based oxide is represented by the following chemical formula (1),
Li.sub.1+aNi.sub.xCo.sub.yMn.sub.zM.sub.vO.sub.2-bA.sub.b  (1) wherein, 0<a≤0.2, 0<x≤0.4, 0<y≤0.4, 0.5≤z≤0.9, 0≤v≤0.2, a+x+y+z+v=1, and 0≤b≤0.5; M is one or more elements selected from the group consisting of Al, Zr, Zn, Ti, Mg, Ga, In, Ru, Nb, and Sn; and A is one or more elements selected from the group consisting of P, N, F, S and Cl; wherein (i) lithium tungsten (W) compound, or the (i) lithium tungsten (W) compound and (ii) tungsten (W) compound
are contained on the lithium-rich lithium manganese-based oxide; in an amount of 0.1% to 7% by weight based on the total weight of the positive electrode active material, wherein the (i) lithium tungsten (W) compound includes a composite of the (ii) tungsten (W) compound and a lithium.

A method embodiment involves preparing single metal or mixed transition metal chalcogenide using exfoliation of two or more different bulk transition metal dichalcogenides in a manner to form an intermediate hetero-layered transition metal chalcogenide structure, which can be treated to provide a single-phase transition metal chalcogenide.

A modified garnet-type solid electrolyte, includes: a garnet-type solid electrolyte; a modification layer, such that the modification layer is formed on at least one side of the garnet-type solid electrolyte, and possesses a three-dimensional crosslinking structure comprising at least one strongly acidic lithium salt and at least one weakly acidic lithium salt. A method of forming a modified garnet-type solid electrolyte, includes: exposing a garnet-type solid electrolyte in air to form a pre-passivation layer; mixing solutions of strong acid and weakly acidic salt to form a mixed solution; chemically treating at least one side of the garnet-type solid electrolyte with the mixed solution; and forming a modification layer on the at least one side of the garnet-type solid electrolyte.

A thermistor material composed of Ca.sub.1-xYb.sub.xCeNbWO.sub.8(0≤x≤0.2) can be used in a wide temperature range from 25 to 800° C. It is made from high-pure CaCO.sub.3, CeO.sub.2, NbO.sub.5, WO.sub.3 and Yb.sub.2O.sub.3. These ceramic materials with a scheelite structure can be obtained after mixing, grinding, calcination, pressing, cold isostatic pressing and high-temperature sintering, etc. The values of material constant B.sub.300° C./600° C. and ρ.sub.25° C. of thermistor materials are in the range of 6465K-6732K, 4.06×10.sup.7Ω.cm-8.63×10.sup.7Ω.cm. The thermistor material has a good thermostability and significant negative temperature coefficient (NTC) characteristic in the temperature range of 25° C. to 800° C., could be used as a potential for fabricating high-temperature thermistor sensors.

An infrared-shielding nanoparticle dispersion has a property whereby visible light is adequately transmitted, and light in the near-infrared region is adequately shielded. The infrared-shielding nanoparticles include a plural aggregate of electroconductive particles composed of a tungsten oxide expressed by the general formula WyOz (where W is tungsten, O is oxygen, and 2.2≤z/y≤2.999), and/or a composite tungsten oxide expressed by the general formula MxWyOz (where M is one or more elements selected from H, alkali metals, alkaline-earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I; W is tungsten; O is oxygen; 0.001≤x/y≤1.1; and 2.2≤z/y≤3.0).

A solid electrolyte for an all-solid-state sodium battery, represented by formula: Na.sub.3−xSb.sub.1−xα.sub.xS.sub.4, wherein α is selected from elements that provide Na.sub.3−xSb.sub.1−xα.sub.xS.sub.4 exhibiting a higher ionic conductivity than Na.sub.3SbS.sub.4, and x is 0<x<1.

A coated substrate is provided that comprises: a substrate; and a barrier coating comprising a compound having the formula: Ln.sub.2ABO.sub.8, where Ln comprises scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, or mixtures thereof; A comprises Si, Ti, Ge, Sn, Ce, Hf, Zr, or a combination thereof; and B comprises Mo, W, or a combination thereof. In one embodiment, B comprises Mo. A gas turbine is also provided that comprises the coated substrate described above.

A mixed oxide catalyst for the oxidative coupling of methane can include a catalyst with the formula A.sub.aB.sub.bC.sub.cD.sub.dO.sub.x, wherein: element A is selected from alkaline earth metals; elements B and C are selected from rare earth metals, and wherein elements B and C are different rare earth metals; the oxide of at least one of A, B, C, and D has basic properties; the oxide of at least one of A, B, C, and D has redox properties; and elements A, B, C, and D are selected to create a synergistic effect whereby the catalytic material provides a methane conversion of greater than or equal to 15% and a C.sub.2.sup.+ selectivity of greater than or equal to 70%. Systems and methods can include contacting the catalyst with methane and oxygen and purifying or collecting C.sub.2.sup.+ products.

A printable ammonium-based chalcogenometalate fluid may include an ammonium-based chalcogenometalate precursor; an aqueous solvent; water; and a dopant; wherein, in the presence of heat, the printable ammonium-based chalcogenometalate fluid dissipates to form a transition metal dichalcogenide having the form MX2 with the dopant distributed therethrough.

The present disclosure is directed to variable composition ceramics. Zr.sub.(2−x)Hf.sub.(x)WP.sub.2O.sub.12 and Hf.sub.2WP.sub.2O.sub.12 exhibit large negative thermal expansion that is linear over a large temperature range up to at least 900° C., These new ceramic material particles may be mixed with polymers to make a composite suitable for use in backsheets for photovoltaic modules or in other applications. The thermal expansion coefficient of the composite can be tailored to match that of the solar cell in order to reduce stress resulting from daily thermal cycling.