Kaneka Corporation

Ayumi Takaoka

Masato Kuratsu

Akiko Waki

Yukimasa Niwa

Fujika Ogaki

The present invention is intended to provide a nonaqueous electrolyte secondary battery that is suppressed in generation of a gas and a micro short circuit of a negative electrode, while exhibiting an excellent rate characteristic. The present invention relates to a nonaqueous electrolyte secondary battery having a sealed bodythat encloses a positive electrode, a nonaqueous electrolyte solution, a negative electrode, and a separatorformed of an electrically insulating material. The negative electrodeis formed by forming a negative electrode active material layer, which contains at least a negative electrode active materialand a negative electrode binder, on a current collector. The negative electrode active materialcontains a titanium compound as a main component, the titanium compound having a particle diameter of 0.1 &#x3bc;m or more and 20.0 &#x3bc;m or less. The negative electrode binderis an acid-modified PVdF obtained by introducing a carboxyl group into a polyvinylidene fluoride (PVdF). A negative electrode water content in the sealed bodyis 400 ppm or less.

Nonaqueous electrolyte secondary battery

A method for producing a positive electrode containing a positive electrode active material and/or a negative electrode containing a negative electrode active material. The method includes a process for producing an electrode slurry including: a first process in which a positive or negative electrode active material, a conductive additive, and a nonaqueous solvent are mixed to obtain a slurry; and a second process in which the slurry is diluted or concentrated and then mixed to obtain the electrode slurry. In the first process, the mixing is performed such that the obtained slurry has a water content of 1000 ppm or less and a viscosity of 500 cP or more and 8000 cP or less, and, in the second process, the mixing is performed such that a water content of the obtained electrode slurry is maintained at the water content of the slurry after the first process is completed.

Method for producing electrode for lithium-ion secondary battery

The present invention provides a nonaqueous electrolyte secondary battery characterized by a significantly smaller amount of gas formation and excellent cycle stability exhibited during cycle testing even when a titanium compound is used for a negative electrode. A nonaqueous electrolyte secondary battery is structured to have a casing, encapsulating a positive electrode, nonaqueous electrolyte, and a negative electrode facing the positive electrode across a separator. The negative electrode contains a titanium compound as a negative-electrode active material,

Nonaqueous electrolyte secondary battery, and positive electrode of nonaqueous electrolyte secondary battery

A non-aqueous electrolyte secondary battery comprising an enclosure in which plural kinds of positive electrodes having a positive electrode active material; a non-aqueous electrolyte; a negative electrode containing a titanium compound as a main component of a negative electrode active material; and a separator held between the positive electrode and the negative electrode and formed from an electrical insulating material are enclosed, which comprises a separator-holding negative electrode which is held by the separator from both sides thereof and is disposed between one of the positive electrodes and the other one of the positive electrode adjacent thereto, the separator-holding negative electrode serving as the negative electrode, and wherein the plural kinds of the positive electrodes comprises a first positive electrode containing a layered rock salt compound as the positive electrode active material, and a second positive electrode whose main component is a positive electrode active material different in kind from the layered rock salt compound. According to the battery, even when the titanium compound is used for the negative electrode, the amount of gas generated during a cycle test is remarkably decreased, and the cycle stability is excellent.

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Osaka, Japan

Ayumi Takaoka