Abstract: The present invention is directed to a positive electrode active material for non-aqueous electrolyte secondary batteries that can reduce direct-current resistance while it contains a nickel-containing lithium transition metal oxide with a high Ni content. The positive electrode active material contains lithium borate and a nickel-containing lithium transition metal oxide (Ni?80 mol %) having a layered structure. The nickel-containing lithium transition metal oxide is composed of secondary particles formed by aggregation of primary particles. Lithium borate is attached to the surfaces of the primary particles. The proportion b of lithium borate with respect to the total molar amount of metal elements other than lithium in the nickel-containing lithium transition metal oxide is in the range of 0 mol %<b?0.5 mol % on a boron element basis. The porosity h of the secondary particles is in the range of 2%<h<6%.

Abstract: A nonaqueous electrolyte secondary battery includes a positive electrode containing a positive electrode active material, a negative electrode, and a nonaqueous electrolyte. The positive electrode active material includes lithium nickel complex oxide, and the lithium nickel oxide has a layered rock-salt structure and is represented by a composition formula of LixNiyMzO2 (where M is at least one metal element selected from the group consisting of Co, Al, Mg, Ca, Cr, Zr, Mo, Si, Ti, and Fe, and x, y, and z satisfy 0.95?x?1.05, 0.8?y?1, 0?z?0.2, and y+z=1). A half width n of a (104) diffraction peak in an X-ray diffraction pattern is 0.13° or less, and the content of the positive electrode active material with a particle size of 3.41 ?m or less is 2 volume % or less based on a total amount of the positive electrode active material contained in the positive electrode.

Abstract: A positive electrode active material for nonaqueous electrolyte secondary batteries which allows the capacity of nonaqueous electrolyte secondary batteries to be increased and offers a smaller decrease in charge discharge cycle characteristics, and to provide a nonaqueous electrolyte secondary battery having such a positive electrode active material. A positive electrode active material for nonaqueous electrolyte secondary batteries according to the present invention includes a composite oxide containing Li, Ni, Co, Al, W and additive elements M, the proportion of Ni in the composite oxide being not less than 80 mol % relative to the total number of moles of the metal elements except Li, the additive elements M including at least either of an alkaline earth metal element and an alkali metal element except Li, and a tetravalent or higher valent element, the average valence of the additive elements M being not less than 3.6.

Abstract: A non-aqueous electrolyte secondary battery according to one embodiment includes a positive electrode, a negative electrode, and a non-aqueous electrolyte. The positive electrode has lithium composite oxide particles containing 80 mol % or more but less than 100 mol % of Ni with respect to the total number of moles of metal elements excluding Li. The lithium composite oxide particles include particles (32) having a stair-like structure in which three or more layers of a flat surface (30) having a periphery length of 1 ?m or more are layered.

Abstract: A positive electrode active material for a nonaqueous electrolyte secondary battery contains silicon and lithium nickel complex oxide having a layered rock-salt structure and is composed of secondary particles formed of aggregated primary particles. Lithium nickel complex oxide contains 80 mol % or more of nickel, based on the total amount of metal excluding lithium, silicon content is 0.6 mass % or less based on the total amount of the positive electrode active material, and a porosity of the positive electrode active material is 0% or more and 1% or less.

Abstract: A nonaqueous electrolyte secondary battery includes a positive electrode containing a positive electrode active material, a negative electrode, and a nonaqueous electrolyte. The positive electrode active material includes lithium nickel complex oxide, and the lithium nickel oxide has a layered rock-salt structure and is represented by a composition formula of LixNiyMzO2 (where M is at least one metal element selected from the group consisting of Co, Al, Mg, Ca, Cr, Zr, Mo, Si, Ti, and Fe, and x, y, and z satisfy 0.95?x?1.05, 0.8?y?1, 0?z?0.2, and y+z=1). A half width n of a (104) diffraction peak in an X-ray diffraction pattern is 0.13° or less, and the content of the positive electrode active material with a particle size of 3.41 ?m or less is 2 volume % or less based on a total amount of the positive electrode active material contained in the positive electrode.

Abstract: The present invention is directed to a positive electrode active material for non-aqueous electrolyte secondary batteries that can reduce direct-current resistance while it contains a nickel-containing lithium transition metal oxide with a high Ni content. The positive electrode active material contains lithium borate and a nickel-containing lithium transition metal oxide (Ni?80 mol %) having a layered structure. The nickel-containing lithium transition metal oxide is composed of secondary particles formed by aggregation of primary particles. Lithium borate is attached to the surfaces of the primary particles. The proportion b of lithium borate with respect to the total molar amount of metal elements other than lithium in the nickel-containing lithium transition metal oxide is in the range of 0 mol %<b?0.5 mol % on a boron element basis. The porosity h of the secondary particles is in the range of 2%<h<6%.

Abstract: A positive electrode active material for a nonaqueous electrolyte secondary battery contains silicon and lithium nickel complex oxide having a layered rock-salt structure and is composed of secondary particles formed of aggregated primary particles. Lithium nickel complex oxide contains 80 mol % or more of nickel, based on the total amount of metal excluding lithium, silicon content is 0.6 mass % or less based on the total amount of the positive electrode active material, and a porosity of the positive electrode active material is 0% or more and 1% or less.