Ngk Insulators, Inc.

Seiko Epson Corporation

Shigeki Okada

Yukinobu Yura

Yukihisa Takeuchi

Natsumi Shimogawa

Tsutomu Nanataki

Toshikazu Hirota

Akira Urakawa

Nobuyuki Kobayashi

Jun Yoshikawa

Ryuta Sugiura

Naoto Ohira

Makoto Ohmori

Nobuo Takahashi

Shuichi Ozawa

Masao Takahashi

Kazuki Maeda

Kengo Oishi

Nobou Takahashi

Yura Yukinobu

Provided is a lithium complex oxide sintered plate for use in a positive electrode of a lithium secondary battery. The lithium complex oxide sintered plate has a structure in which a plurality of primary grains having a layered rock-salt structure are bonded, and has a porosity of 3 to 40%, a mean pore diameter of 15 μm or less, an open porosity of 70% or more, and a thickness of 15 to 200 μm. The plurality of primary grains has a primary grain diameter, i.e., a mean diameter of the primary grains, of 20 μm or less and a mean tilt angle of more than 0° to 30° or less. The mean tilt angle is a mean value of the angles defined by the (003) planes of the primary grains and the plate face of the lithium complex oxide sintered plate.

Lithium composite oxide sintered body plate

Provided is a lithium secondary battery including a positive electrode layer composed of a lithium complex oxide sintered body, a negative electrode layer composed of a titanium-containing sintered body, a ceramic separator, an electrolytic solution, and an exterior body including a closed space, the closed space accommodating the positive electrode layer, the negative electrode layer, the ceramic separator, and the electrolytic solution, wherein the positive electrode layer, the ceramic separator, and the negative electrode layer are bonded together, the ceramic separator is composed of MgO and glass, the glass has an average grain size of 0.5 to 25 μm, and a ratio of the average grain size of the glass to the average grain size of MgO is 1.5 to 85.

Lithium secondary battery

Provided is a lithium secondary battery including a positive electrode layer composed of a cobalt-containing lithium complex oxide sintered body, a negative electrode layer composed of a titanium-containing sintered body, a ceramic separator interposed between the positive electrode layer and the negative electrode layer and containing MgO, an electrolytic solution with which the positive electrode layer, the negative electrode layer, and the ceramic separator are impregnated, and an exterior body including a closed space, the closed space accommodating the positive electrode layer, the negative electrode layer, the ceramic separator, and the electrolytic solution, wherein the positive electrode layer, the ceramic separator, and the negative electrode layer are bonded together, and the interface between the negative electrode layer and the ceramic separator has a larger roughness than the interface between the positive electrode layer and the ceramic separator.

Provided is a lithium secondary battery including a positive electrode layer composed of a lithium complex oxide sintered body, a negative electrode layer composed of a titanium-containing sintered body, a ceramic separator interposed therebetween, an electrolytic solution, and an exterior body including a closed space, which accommodates the positive electrode layer, the negative electrode layer, the ceramic separator, and the electrolytic solution, wherein the positive electrode layer, the ceramic separator, and the negative electrode layer are bonded together, a ratio C/A of a capacity C of the positive electrode layer to a capacity A of the negative electrode layer is 1.03 to 2.30, a ratio Tc/Ta of a thickness Tc of the positive electrode layer to a thickness Ta of the negative electrode layer is 0.50 to 2.00, the thickness Tc is 50 to 1000 μm, and the thickness Ta is 50 to 1200 μm.

Provided is a lithium secondary battery including a positive electrode layer composed of a lithium complex oxide sintered body, a negative electrode layer composed of a titanium-containing sintered body, a ceramic separator interposed between the positive electrode layer and the negative electrode layer, an electrolyte with which at least the ceramic separator is impregnated, and an exterior body comprising a closed space, the closed space accommodating the positive electrode layer, the negative electrode layer, the ceramic separator, and the electrolyte. The positive electrode layer, the ceramic separator, and the negative electrode layer form one integrated sintered plate as a whole, whereby the positive electrode layer, the ceramic separator, and the negative electrode layer are bonded together.

Disclosed is a lithium complex oxide sintered plate including a plurality of primary grains having a layered rock-salt structure, the primary grains being bonded. The lithium complex oxide has a composition represented by the formula: Li(CoM)O(wherein, 1.0&#x2264;x&#x2264;1.1, 0&#x3c;y&#x2264;0.1, 0&#x2264;&#x3b4;&#x3c;1, and M is at least one selected from the group consisting of Mg, Ni, Al, and Mn), and the primary grains have a mean tilt angle of more than 0&#xb0; to 30&#xb0; or less, the mean tilt angle being a mean value of the angles defined by the (003) planes of the primary grains and the plate face of the lithium complex oxide sintered plate.

Lithium composite oxide sintered body plate and lithium secondary battery

Provided is a lithium complex oxide sintered plate for use in a positive electrode of a lithium secondary battery. The lithium complex oxide sintered plate has a structure in which a plurality of primary grains having a layered rock-salt structure are bonded, and has a porosity of 3 to 40%, a mean pore diameter of 15 &#x3bc;m or less, an open porosity of 70% or more, and a thickness of 15 to 200 &#x3bc;m. The plurality of primary grains has a primary grain diameter, i.e., a mean diameter of the primary grains, of 20 &#x3bc;m or less and a mean tilt angle of more than 0&#xb0; to 30&#xb0; or less. The mean tilt angle is a mean value of the angles defined by the (003) planes of the primary grains and the plate face of the lithium complex oxide sintered plate.

Provided is a lithium titanate sintered plate for use in a negative electrode of a lithium secondary battery. The lithium titanate sintered plate has a structure in which a plurality of primary grains are bonded, and has: a thickness of 10 to 290 &#x3bc;m; a primary grain diameter of 0.70 &#x3bc;m or less, the primary grain diameter being a mean grain diameter of the primary grains; a porosity of 21 to 45%; an open pore rate of 60% or more; a mean pore aspect ratio of 1.15 or more; a ratio of 30% or more of pores having an aspect ratio of 1.30 or more to all the pores; and a mean pore diameter of 0.70 &#x3bc;m or less, wherein volume-based D10 and D90 pore diameters satisfy the relationship: 4.0&#x2264;D90/D10&#x2264;50.

Lithium titanate sintered plate

A positive electrode is configured by a plurality of mutually bonded primary particles respectively composed of a lithium composite oxide having a layered rock-salt structure. An average orientation angle of the plurality of primary particles relative to a plate face direction parallel to a plate face is more than 0&#xb0; and less than or equal to 30&#xb0;. An aggregate area of primary particles that have an orientation angle relative to the plate face direction of more than 0&#xb0; and less than or equal to 30&#xb0; is greater than or equal to 70% relative to a total area of the plurality of primary particles, in a cross section.

Positive electrode

The plate-shaped lithium composite oxide is configured by a plurality of mutually bonded primary particles respectively composed of a lithium composite oxide having a layered rock-salt structure. When fully charged, an expansion-contraction ratio E in a plate face direction parallel to a plate face is less than or equal to 0.5%.

Plate-shaped lithium composite oxide

An object of the present invention is to provide a lithium secondary battery cathode which can more improve characteristics of the battery. The cathode of the present invention includes an electroconductive cathode current collector, a plurality of plate-like particle formed of a cathode active material, and a binder containing microparticles formed of the cathode active material and being smaller than the plate-like particles. The plate-like particles are formed so as to have an aspect ratio of 4 to 50. The plate-like particles are arranged such that the particles cover the surface of the cathode current collector surface at a percent area of 85 to 98%. The binder is disposed so as to intervene between two adjacent plate-like particles.

Lithium secondary battery cathode

A cathode active material precursor particle, a method for producing thereof and a method for producing cathode active material for a lithium secondary battery. The cathode active material precursor particle is capable of forming a cathode active material for a lithium secondary battery including a lithium composite oxide having a layered rock salt structure through lithium incorporation. The particles are characterized by the cathode active material precursor particle being formed into a substantially spherical shape and includes therein a large number of voids in a substantially uniform manner; and the cathode active material precursor particle has: an average particle diameter D50 of 0.5 to 5 &#x3bc;m; a specific surface area of 3 to 25 m/g; and a relative tap density, which is a value obtained by dividing a tap density by a theoretical density of a material constituting the cathode active material precursor particle, of 0.25 to 0.4.

Cathode active material precursor particle, method for producing thereof and method for producing cathode active material for lithium secondary battery

The present invention relates to a cathode and a cathode active material plate for a lithium secondary battery, and the production method thereof. There is a feature of the present invention in that grooves consisting of a concave portion and having an infinite form (for example, an infinite cell-like shape) in a planar view are formed in a principal surface of the cathode active material plate.

Cathode and a cathode active material plate for a lithium secondary battery and method for manufacturing these

An object of the present invention is to provide a lithium secondary battery cathode which can more improve characteristics of the battery. The cathode of the present invention includes a first layer composed of a plate-like cathode active material and a second layer containing particles of the cathode active material and a binder, the second layer being joined to the first layer in a stacked state.

A sheet body includes an electrolyte layer, a fuel electrode layer formed on the upper surface of the electrolyte layer, and an air electrode layer formed on the lower surface of the electrolyte layer, wherein these layers are stacked and fired in such a manner that the electrolyte layer is sandwiched between the fuel electrode layer and the air electrode layer. The fuel electrode layer is a porous layer including a first layer on a side close to the electrolyte layer made of fine particles of Ni and YSZ, and a second layer on a side apart from the electrolyte layer made of fine particles of Ni, YSZ, and ZrSiO. The zircon particles are uniformly distributed in the second layer in the plane direction and in the stacking direction.

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Nishio, Japan

Shigeki Okada