The disclosure relates to cerium based particles having a rough surface and their use as a component of a polishing composition, especially for chemical mechanical polishing. The cerium based particles have substantially the shape of polyhedrons which have one or more faces with protrusions thereon, said protrusions being integrally formed with said cerium based particles. The present disclosure also relates to the method of preparation of the cerium based particles.

The disclosure relates to cerium based particles having a rough surface and their use as a component of a polishing composition, especially for chemical mechanical polishing. The cerium based particles have substantially the shape of polyhedrons which have one or more faces with protrusions thereon, said protrusions being integrally formed with said cerium based particles. The present disclosure also relates to the method of preparation of the cerium based particles.

Disclosed are a composite oxide which is capable of maintaining a large volume of pores even used in a high temperature environment, and which has excellent heat resistance and catalytic activity, as well as a method for producing the composite oxide and a catalyst for exhaust gas purification employing the composite oxide. The composite oxide contains cerium and at least one element selected from aluminum, silicon, or rare earth metals other than cerium and including yttrium, at a mass ratio of 85:15 to 99:1 in terms oxides, and has a property of exhibiting a not less than 0.30 cm.sup.3/g, preferably not less than 0.40 cm.sup.3/g volume of pores with a diameter of not larger than 200 nm, after calcination at 900° C. for 5 hours, and is suitable for a co-catalyst in a catalyst for vehicle exhaust gas purification.

A lanthanum molybdenum composite oxide is provided. The lanthanum molybdenum composite oxide has a primary crystal phase formed of La.sub.2Mo.sub.2O.sub.9. The lanthanum molybdenum composite oxide also has a secondary crystal phase formed of a lanthanum molybdenum composite oxide species other than La.sub.2Mo.sub.2O.sub.9. The secondary crystal phase may contain at least one species selected from a group consisting of La.sub.2Mo.sub.3O.sub.12, La.sub.6MoO.sub.12, La.sub.7Mo.sub.7O.sub.30, La.sub.2Mo.sub.4O.sub.15, La.sub.2MoO.sub.6, La.sub.4MoO.sub.9, and LaMo.sub.2O.sub.5.

A lanthanum molybdenum composite oxide is provided. The lanthanum molybdenum composite oxide has a primary crystal phase formed of La.sub.2Mo.sub.2O.sub.9. The lanthanum molybdenum composite oxide also has a secondary crystal phase formed of a lanthanum molybdenum composite oxide species other than La.sub.2Mo.sub.2O.sub.9. The secondary crystal phase may contain at least one species selected from a group consisting of La.sub.2Mo.sub.3O.sub.12, La.sub.6MoO.sub.12, La.sub.7Mo.sub.7O.sub.30, La.sub.2Mo.sub.4O.sub.15, La.sub.2MoO.sub.6, La.sub.4MoO.sub.9, and LaMo.sub.2O.sub.5.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

A composite cathode active material, a method of preparing the composite cathode active material, and a lithium secondary battery including a cathode including the composite cathode active material are provided. The composite cathode active material includes: a nickel-based active material including about 60 mol % or more of nickel; and a coating layer on a surface of the nickel-based active material, the coating layer including a lanthanide composite. The composite cathode active material includes or is in the form of single crystal particles having an average particle diameter in a range of about 2 μm to about 8 μm.

A composite cathode active material, a method of preparing the composite cathode active material, and a lithium secondary battery including a cathode including the composite cathode active material are provided. The composite cathode active material includes: a nickel-based active material including about 60 mol % or more of nickel; and a coating layer on a surface of the nickel-based active material, the coating layer including a lanthanide composite. The composite cathode active material includes or is in the form of single crystal particles having an average particle diameter in a range of about 2 μm to about 8 μm.

Disclosed herein are electrolytes having increased proton conduction and steam tolerance for use in solid oxide electrolysis cells (SOECs). The disclosed SOECs provide an enhanced means for obtaining hydrogen. The disclosed SOECs provide enhanced conductivity and stability and, therefore, result in higher performance when used to fabricate electrolysis cells, fuel cells, and reversible cells.