Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Sanyo Electric Co., Ltd.

Yoshinori Aoki

Takeshi Ogasawara

Motoharu Saitou

Toshinobu Kanai

Hiroshi Kawada

Motoharu Saito

Kenichi Hotehama

Katsuya Inoue

Masakazu Togo

The positive electrode active material for a non-aqueous electrolyte secondary cell according to an embodiment of the present disclosure is characterized in having a Ni-containing lithium transition metal oxide having a layered structure; the proportion of Ni in the lithium transition metal oxide being 91 to 96 mol % relative to the total number of moles of metal elements excluding Li; a transition metal being present in the Li layer of the layered structure at an amount of 1 to 2.5 mol % relative to the total number of moles of transition metals in the Ni-containing lithium transition metal oxide; and the Ni-containing lithium transition metal oxide being such that the half width n of the diffraction peak for the (208) plane in an X-ray diffraction pattern obtained by X-ray diffraction is 0.30°≤n≤0.50°.

Positive electrode active material for non-aqueous electrolyte secondary cell, and non-aqueous electrolyte secondary cell

A positive electrode active material for non-aqueous electrolyte secondary batteries comprises a lithium transition metal oxide containing Ni, Mn, Co, and Al and having a layered structure, wherein the content ratio of Ni in the lithium transition metal oxide is 75 to 95 mol %, the content ratio of Mn in the lithium transition metal oxide is equal to or greater than the content ratio of Co in the lithium transition metal oxide, the content ratio of Co in the lithium transition metal oxide is 0.5 to 2 mol %, the content ratio of a metal element other than Li in an Li layer in the layered structure is 1 to 2.5 mol %, and, in the lithium transition metal oxide, the half width n of a diffraction peak for (208) plane of an X-ray diffraction pattern as measured by X-ray diffraction is as follows: 0.30°≤n≤0.50°.

Positive electrode active material for non-aqueous electrolyte secondary batteries, and non-aqueous electrolyte secondary battery

The positive electrode active material for a non-aqueous electrolyte secondary cell according to an embodiment of the present disclosure is characterized in having a Ni-containing lithium transition metal oxide having a layered structure; the proportion of Ni in the lithium transition metal oxide being 91 to 96 mol % relative to the total number of moles of metal elements excluding Li; a transition metal being present in the Li layer of the layered structure at an amount of 1 to 2.5 mol % relative to the total number of moles of transition metals in the Ni-containing lithium transition metal oxide; and the Ni-containing lithium transition metal oxide being such that the half width n of the diffraction peak for the (208) plane in an X-ray diffraction pattern obtained by X-ray diffraction is 0.30&#xb0;&#x2264;0&#x2264;0.50&#xb0;.

A positive electrode active material or non-aqueous electrolyte secondary batteries comprises a Co-containing lithium transition metal oxide containing Ni, Mn, and an arbitrary element and having a layered structure, wherein the content ratio of Ni in the lithium transition metal oxide is 75 to 95 mol %, the content ratio of Mn in the lithium transition metal oxide is equal to or greater than the content ratio of Co in the lithium transition metal oxide, the content ratio of Co in the lithium transition metal oxide is 0 to 2 mol %, the content ratio of a metal element other than Li in an Li layer in the layered structure is 1 to 2.5 mol %, and, in the lithium transition metal oxide, the half width n of a diffraction peak for (208) plane of an X-ray diffraction pattern as measured by X-ray diffraction is as follows: 0.30&#xb0;&#x2264;n&#x2264;0.50&#xb0;.

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&#x2265;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 %&#x3c;b&#x2264;0.5 mol % on a boron element basis. The porosity h of the secondary particles is in the range of 2%&#x3c;h&#x3c;6%.

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 LiNiMO(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&#x2264;x&#x2264;1.05, 0.8&#x2264;y&#x2264;1, 0&#x2264;z&#x2264;0.2, and y+z=1). A half width n of a (104) diffraction peak in an X-ray diffraction pattern is 0.13&#xb0; or less, and the content of the positive electrode active material with a particle size of 3.41 &#x3bc;m or less is 2 volume % or less based on a total amount of the positive electrode active material contained in the positive electrode.

Nonaqueous electrolyte secondary battery

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.

Positive electrode active material for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery

A positive electrode plate () includes a current collector () and a mixture layer () disposed on the current collector (). The mixture layer () has a thin portion () with a thickness of less than 200 &#x3bc;m disposed on an inner coil half of the current collector () and a thick portion () having a larger thickness than the thin portion (), the thick portion () having a yield loop height H measured by a stiffness test of 6 mm&#x3c;H&#x3c;15 mm.

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Hyogo, Japan

Yoshinori Aoki