Sony Corporation

Panasonic Corporation

Sanyo Electric Co., Ltd.

Yasuo Fukase

Masatoshi Takahashi

Mikinari Shimada

Masayuki Nagamine

Shinji Kasamatsu

Katsuhiko Watanabe

Masato Iwanaga

The invention provides a method for evaluating the safety of a battery under an internal short-circuit condition. The battery includes: an electrode group including a positive electrode, a negative electrode, and an insulating layer for electrically insulating the electrodes, which are wound or laminated; an electrolyte; a housing for housing the electrode group and the electrolyte; and a current-collecting terminal for electrically connecting the electrode group and the housing. The method of the invention includes: placing a foreign object at a location inside the electrode group of the battery where the positive electrode and the negative electrode face each other; and pressing the location by the pressure applied by a pressing tool to locally crush the insulating layer between the positive and negative electrodes, thereby causing an internal short-circuit. The contact area of the electrode group and the pressing tool during the pressing is larger than the area of a rectangle circumscribed about the foreign object. A short-circuit test is conducted at a given location inside the battery to comprehensively evaluate the safety of the battery under an internal short-circuit condition.

Method for evaluating battery safety under internal short-circuit condition, battery and battery pack whose safety is identified by internal short-circuit safety evaluation method, and method for producing the same

An insulating plate of a nonaqueous electrolyte secondary cell is interposed between a cell element and a cover member in a nonaqueous electrolyte secondary cell including the cell element formed by stacking cathodes and anodes through separators, a cell can including a can body which houses the cell element and the cover member which closes an opening of the can body to seal the cell element, and an electrolyte injected into the cell can. The insulating plate includes a plate-shaped insulating plate body having insulating property, an injection hole which passes through the insulating plate body in the thickness direction and through which the electrolyte can be injected, and a filter member permeable to only the electrolyte and provided on one of the surfaces of the insulating plate body so as to cover the injection hole.

Insulating plate of nonaqueous electrolyte secondary cell, nonaqueous electrolyte secondary cell, and method for producing insulating plate of nonaqueous electrolyte secondary cell

Growing community of inventors

Fukushima, Japan

Yasuo Fukase