Ishihara Sangyo Kaisha, Ltd.

Tsunehisa Takeuchi

Masatoshi Honma

Kazuyoshi Takeshima

Yusuke Okuda

Naoya Nagahashi

Hiroomi Horie

Atsushi Ishizawa

Provided is lithium titanate that is readily pulverized, and readily dispersed in a binding agent. The lithium titanate is characterized in that the value of a degree of pulverization Zd representing the ratio of the 50% cumulative diameter pre- and post-pulverization is 2 or greater. The lithium titanate is produced by the following steps (1)-(3). (1) a step in which titanyl sulfate or titanium sulfate is thermally hydrolyzed to produce metatitanic acid; (2) a step in which a slurry containing the metatitanic acid is prepared, and the slurry, subsequent to neutralization to bring the pH to 6.0-9.0, undergoes solid-liquid separation, to produce a metatitanic acid-containing titanium starting material having a BET specific surface area of 100-400 m/g, and in which the sulfuric acid (SO) content is 0.01-2.0 mass % with respect to the amount of metatitanic acid, on a TiO-converted basis; and (3) a step in which the titanium starting material and a lithium compound are mixed and baked.

Process for manufacturing lithium titanium oxides

The invention provides a low-cost, efficient method for producing lithium titanate that is useful for applications in electric storage devices. The desired lithium titanate can be obtained by heating at least (1) titanium oxide having a BET single point specific surface area of 50 to 450 m/g based on nitrogen adsorption and (2) a lithium compound. Preferably the titanium oxide and lithium compound are heated together with (3) a lithium titanate compound having the same crystal structure as the desired lithium titanate. Preferably these ingredients are dry-mixed before heating.

Titanium raw material for lithium titanate production and method for producing lithium titanate using same

Provided is a process for manufacturing, at a low cost and efficiently, lithium titanium oxides which are useful for electricity storage devices. A desired lithium titanium oxide can be obtained by heating at least both (1) a titanium compound and (2) a lithium compound that has a volume-mean particle diameter of 5 &#x3bc;m or less. The lithium compound is preferably obtained by adjusting the volume-mean particle diameter to 5 &#x3bc;m or less by pulverizing. It is preferable that the titanium compound and the lithium compound are heated together with (3) a lithium titanium oxide compound that has the same crystal structure as that of objective lithium titanium oxide. It is preferable that these materials are dry-blended prior to the heating.

A method for producing a lithium titanate precursor includes the step of grinding a lithium compound and a titanium compound in a state where these compounds coexist. More preferably, a method for producing a lithium titanate precursor includes the steps of; mixing a lithium compound and a titanium compound; and grinding the lithium compound and the titanium compound in a state where these compounds coexist by the mixing.

Method for producing lithium titanate precursor, method for producing lithium titanate, lithium titanate, electrode active material, and electricity storage device

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Yokkaichi, Japan

Tsunehisa Takeuchi