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 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.

The present invention relates to a lithium composite oxide, a positive electrode active material for a lithium secondary battery including the lithium composite oxide, and a lithium secondary battery using a positive electrode including the positive electrode active material.

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).

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).

An object of the present invention is to provide a positive electrode material for a nonaqueous electrolyte secondary battery, which is capable of inhibiting the gelation of a positive electrode composite material paste without decreasing the charge and discharge capacity and the output characteristics, when used as a positive electrode material for batteries. The positive electrode active material for a nonaqueous electrolyte secondary battery comprises a mixture containing a lithium metal composite oxide represented by a general formula Li.sub.aNi.sub.1-x-y-zCo.sub.xMn.sub.yM.sub.zO.sub.2 (wherein, 0.03≤x≤0.35, 0≤y≤0.35, 0≤z≤0.05, 0.97≤a≤1.30, and M is at least one type of element selected from V, Fe, Cu, Mg, Mo, Nb, Ti, Zr, W and Al) and an ammonium tungstate powder, wherein when 5 g of the positive electrode material is mixed with 100 ml of pure water, the mixture is stirred for 10 minutes and then left to stand for 30 minutes, and then the pH of a supernatant fluid at 25° C. was measured, the pH ranges from 11.2 to 11.8.

An object of the present invention is to provide a positive electrode material for a nonaqueous electrolyte secondary battery, which is capable of inhibiting the gelation of a positive electrode composite material paste without decreasing the charge and discharge capacity and the output characteristics, when used as a positive electrode material for batteries. The positive electrode active material for a nonaqueous electrolyte secondary battery comprises a mixture containing a lithium metal composite oxide represented by a general formula Li.sub.aNi.sub.1-x-y-zCo.sub.xMn.sub.yM.sub.zO.sub.2 (wherein, 0.03≤x≤0.35, 0≤y≤0.35, 0≤z≤0.05, 0.97≤a≤1.30, and M is at least one type of element selected from V, Fe, Cu, Mg, Mo, Nb, Ti, Zr, W and Al) and an ammonium tungstate powder, wherein when 5 g of the positive electrode material is mixed with 100 ml of pure water, the mixture is stirred for 10 minutes and then left to stand for 30 minutes, and then the pH of a supernatant fluid at 25° C. was measured, the pH ranges from 11.2 to 11.8.