Sumitomo Metal Mining Company, Ltd.

Panasonic Energy Co., Ltd.

Takahiro Ogawa

Kazuomi Ryoshi

Jun Yokoyama

Tetsufumi Komukai

Tomoko Nakayama

Jiro Okada

Takahiro Toma

Yoshiyuki Matsuura

A positive electrode active material for a lithium ion secondary battery contains a lithium metal composite oxide. The lithium metal composite oxide includes lithium (Li), nickel (Ni), cobalt (Co), and element M (M) in a mass ratio of Li:Ni:Co:M=1+a:1−x−y:x:y (wherein −0.05≤a≤0.50, 0≤x≤0.35, 0≤y≤0.35, and the element M is at least one element selected from Mg, Ca, Al, Si, Fe, Cr, Mn, V, Mo, W, Nb, Ti, Zr, and Ta), wherein when a line analysis is performed with STEM-EELS from a surface of a particle of the lithium metal composite oxide to a center of the particle in a cross-section of the particle during charging at 4.3 V (vs. Li/Li), a thickness of an oxygen release layer, in which an intensity ratio of a peak near 530 eV (1st) to a peak near 545 eV (2nd) at an O-K edge is 0.9 or less, is 200 nm or less.

Positive electrode active material for lithium ion secondary battery, method of manufacturing positive electrode active material for lithium ion secondary battery, and lithium ion secondary battery

The present invention provides a positive electrode active material for a non-aqueous electrolyte secondary battery including a lithium metal composite oxide powder represented by a general formula: LiNiCoMO, wherein 0&#x3c;x&#x2264;0.35, 0&#x2264;y&#x2264;0.35, 0.95&#x2264;z&#x2264;1.30, &#x2212;0.15&#x2264;&#x3b1;&#x2264;0.15, and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti and Al; and a coating layer placed on particle surfaces of the lithium metal composite oxide powder; wherein the coating layer is a mixed-phase of a crystalline phase and an amorphous phase.

Positive electrode active material for non-aqueous electrolyte secondary battery

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Ehime, Japan

Takahiro Ogawa