Ishihara Sangyo Kaisha, Ltd.

Kazuyoshi Takeshima

Masatoshi Honma

Yusuke Okuda

Tsunehisa Takeuchi

Nariaki Moriyama

Naoya Nagahashi

Atsushi Ishizawa

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

Disclosed is lithium titanate having excellent rate properties and useful for electricity storage devices, which is produced by preparing lithium titanate secondary particles that are aggregates of lithium titanate primary particles and forming at least macro-pores on the surfaces of the secondary particles. The lithium titanate can be produced by a process which comprises drying and granulating a slurry comprising crystalline titan oxide, a titanic acid compound and a lithium compound and firing the granulated product to thereby produce lithium titanate secondary particles, wherein (1) the crystalline titan oxide to be used comprises at least two types of crystalline titan oxide particles having different average particle diameters from each other, and/or (2) the crystalline titan oxide is used in an amount at least four-fold larger than that of the titanic acid compound in terms of TiOcontent by weight. The lithium titanate can achieve a satisfactory level of charge-discharge capacity for practical uses when used in a electricity storage device without requiring the use of a carbon-containing substance, such as carbon black, acethylene black or Ketjen black, as an electrically conductive material in combination, in spite of a fact that lithium titanate has an electrically insulating properties by nature.

Lithium titanate, electrode active material and electricity storage device each comprising the 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.

Process for manufacturing lithium titanium oxides

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

Kazuyoshi Takeshima