Mitsui Minings & Melting Co., Ltd.

Toshikazu Matsuyama

Tetsuya Mitsumoto

Shinya Kagei

Hideaki Matsushima

Hitohiko Ide

Daisuke Washida

Yoshimi Hata

Daisuke Inoue

Kyohei Yamaguchi

Provided is a novel positive electrode active material capable of suppressing resistance and improving rate characteristics and cycle characteristics while enhancing lithium ionic conductivity, wherein the surface of particles composed of a spinel-type composite oxide containing Li, Mn, O, and two or more other elements is coated with a lithium ion conductive oxide such as LiNbO. Proposed is a positive electrode active material for an all-solid-type lithium secondary battery, wherein the surface of present core particles composed of a spinel-type composite oxide containing Li, Mn, O, and two or more other elements is coated with an amorphous compound containing Li, A (A represents one or more elements selected from the group consisting of Ti, Zr, Ta, Nb, and Al), and O; and the molar ratio (Li/A) of Li relative to the A element in the surface, as obtained by XPS, is 1.0 to 3.5.

Cathode active material for all-solid-state lithium secondary battery

Provided is a new 5 V class spinel-type lithium manganese-containing composite oxide which enables the expansion of a high potential capacity region and the suppression of gas generation. The 5 V class spinel-type lithium manganese-containing composite oxide has an operating potential of 4.5 V or more at a metal Li reference potential, and contains Li, Mn, O and two or more other elements. The spinel-type lithium manganese-containing composite oxide is characterized in that, in an electronic diffraction image from a transmission electron microscope (TEM), a diffraction spot observed in the Fd-3m structure as well as a diffraction spot not observed in the Fd-3m structure are confirmed.

5V-class spinel-type lithium-manganese-containing composite oxide

A positive electrode active material comprising a lithium metal composite oxide having a layered crystal structure provides a novel lithium metal composite oxide powder which can suppress the reaction with an electrolytic solution and raise the charge-discharge cycle ability of a battery, and can improve the output characteristics of a battery. A lithium metal composite oxide powder comprises a particle having a surface portion where one or a combination of two or more ('surface element A') of the group consisting of Al, Ti and Zr is present, on the surface of a particle comprising a lithium metal composite oxide having a layered crystal structure, wherein the amount of surface LiOH is smaller than 0.10% by weight, and the amount of surface LiCOis smaller than 0.25% by weight; in an X-ray diffraction pattern, the ratio of an integral intensity of the (003) plane of the lithium metal composite oxide to that of the (104) plane thereof is higher than 1.15; and the amount of S obtained by a measurement using ICP is smaller than 0.10% by weight of the lithium metal composite oxide powder (100% by weight).

Lithium metal composite oxide powder

Provided is a new 5 V-class spinel-type lithium-manganese-containing composite oxide capable of achieving both the expansion of a high potential capacity region and the suppression of gas generation. Proposed is the spinel-type lithium-manganese-containing composite oxide comprising Li, Mn, O and two or more other elements, and having an operating potential of 4.5 V or more at a metal Li reference potential, wherein a peak is present in a range of 14.0 to 16.5&#xb0; at 2&#x3b8;, in an X-ray diffraction pattern measured by a powder X-ray diffractometer (XRD) using CuK&#x3b1;1 ray.

The present invention relates to a positive electrode active material including a lithium metal composite oxide having a layer crystal structure, and provides a novel positive electrode active material for a lithium secondary cell, which can suppress the reaction with an electrolyte solution and can raise the charge-discharge cycle ability of the cell, and can make good the output characteristics of the cell. There is proposed a positive electrode active material for a lithium secondary cell, including an active particle having a surface portion where one or a combination of two or more (these are referred to as 'surface element A') of the group consisting of Al, Ti and Zr is present, on a surface of a particle including a lithium metal composite oxide having a layer crystal structure and represented by the general formula: Li1+xM1&#x2212;xO2 (wherein M is one or a combination of two or more (these are referred to as 'constituent element M') of the group consisting of Mn, Co, Ni, transition elements of from the third group elements to the 11th group elements of the periodic table, and typical elements up to the third period of the periodic table), wherein the ratio (CA/CM) of a concentration CA of the surface element A to a concentration CM of the constituent element M is higher than 0 and lower than 0.8, as measured by XPS; the amount of surface lithium impurity is smaller than 0.40% by weight; and in an X-ray diffraction pattern measured by XRD, the ratio (003)/(104) of an integral intensity of the peak originated from the (003) plane to an integral intensity of the peak originated from the (104) plane is higher than 1.15.

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Takehara, Japan

Toshikazu Matsuyama