This positive electrode active material for nonaqueous electrolyte secondary batteries contains: first particles which have an average surface roughness of 4% or less and are mainly configured of a lithium-nickel composite oxide wherein the ratio of Ni relative to the total number of moles of metal elements other than Li is more than 30% by mole; and second particles which are present on the surfaces of the first particles and are mainly configured of at least one hydroxide selected from among hydroxides of lanthanoid elements (excluding La and Ce) and oxyhydroxides.

The present invention relates to a thermistor paste and a manufacturing method thereof. The thermistor paste includes specific contents of thermistor powder, a glass powder, and an organic carrier, in which the organic carrier includes an organic solvent, a binder, and an additive. A thermistor semi-finished product slurry of the present invention has been sintered. The thermistor paste of the present invention excludes a precious metal, such as ruthenium, gold, or platinum, etc., so the production cost can be reduced.

A manganese-based solid solution positive-electrode material, wherein the manganese-based solid solution positive-electrode material has a layered structure, and a chemical formula of the manganese-based solid solution positive-electrode material is aNa.sub.2Mn.sub.xR.sub.1-xO.sub.3.Math.(1a)LiMn.sub.yM.sub.1-O.sub.2, where 0.05a<1, 0<x1, 0.1y1, and each of the R and the M in the chemical formula independently comprises any one or combination of at least two of: alkali metal elements, alkaline earth metal elements, and transition metal elements.

A method for manufacturing a sintered body, the method including heating a mixture that contains a plurality of particles of a metal oxide having a spinel-type structure, and a metal acetylacetonate under pressure at a temperature of from a melting point or higher of the metal acetylacetonate to 600 C. or lower, to form a sintered body that contains the metal oxide having the spinel-type structure.