Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Sanyo Electric Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Masato Fujikawa

Mikinari Shimada

Tomohiko Yokoyama

Keisuke Shimizu

Hajime Nishino

Kaoru Inoue

Shinji Kasamatsu

Hideharu Takezawa

Yasunari Sugita

Kohei Suzuki

Shunsuke Yasui

Kazuki Endo

Daisuke Kishii

Tetsuya Hayashi

Masaya Ugaji

Takayuki Shirane

Kyosuke Miyata

Kazutaka Teramoto

Tatsuya Ishibashi

Koki Inoue

Toshitada Sato

Katsumi Kozu

Akiko Yuasa

Takuya Nakashima

Kenichi Suzuki

Shoichiro Watanabe

Takeshi Enomoto

Keisuke Naito

Toshiyuki Nakatsuji

Akira Nagasaki

Mitsuhiro Takeno

Jun Asakura

Masaru Kawabe

Natsuhiko Mukai

Shin-Ichi Yuasa

Kenichi Honoki

Tetsu Hashimoto

A battery includes a bottomed cylindrical case body that accommodates an electrode body and a bottom-portion insulating plate () that is disposed between the electrode body and a bottom portion of the case body. The bottom portion of the case body has a gas discharge port that opens when an internal pressure of the battery reaches a predetermined pressure. The bottom-portion insulating plate () has a through hole. An aperture ratio, which is a ratio of an area of the through hole with respect to a total area of the insulating plate, is greater than or equal to 10% and less than or equal to 40%. A Young's modulus of the bottom-portion insulating plate at 25&#xb0; C. is 10 GPa or greater.

Battery

The battery is sealed by a sealing member including a safety valve for exhausting the gas generated in the battery to the outside of the battery when the pressure in the battery is increased. A part of the sealing member is formed of a member having a melting point lower than that of high-temperature gas generated in the abnormal time and having a ratio of an area of an opening of the battery case to an area of a gas exhaust hole is 3.0&#xd7;10or more and 9.1&#xd7;10or less.

Sealed type battery

A non-aqueous electrolyte secondary battery includes battery element formed by laminating and winding positive electrode and negative electrode via separator. Positive electrode includes a positive electrode current-collector-exposed portion, in which the positive electrode current collector is exposed over a length dimension of not less than one turn of the winding of battery element in the outermost circumference and an intermediate layer portion of the winding. The negative electrode in a part facing the positive electrode current collector exposed in the intermediate layer portion includes the negative electrode active material layer laminated on the negative electrode current collector. Negative electrode can be provided with a slit at an exposed side with respect to both exposed ends of the positive electrode current-collector-exposed portion.

Non-aqueous electrolyte secondary battery

Even after the battery reaches the last stage of the end of life, the use can be continued. A charging system includes battery pack and charger. During the charge of lithium-ion secondary battery, charge control unit calculates the full charge capacity maintaining rate, sets a first charge current value on the basis of the full charge capacity maintaining rate, and charges the battery. When lithium-ion secondary battery reaches the last stage of the end of life, charge control unit sets a second charge current value lower than the first charge current value set based on the full charge capacity maintaining rate, and charges the battery.

Secondary battery charging system and method, and battery pack

In a battery pack, a plurality of cells are arranged, the cells each have an outlet through which gas generated in the cell is released in one direction, each two of the cells are arranged as one unit, and the each two of the cells are arranged such that directions of gas released through the outlets of the two cells are opposite to each other.

Battery pack

A nonaqueous electrolyte secondary battery includes: an electrode group including a positive electrode plate, a negative electrode plate, and a separator. The positive and negative electrode plates are wound with the separator interposed therebetween. The positive electrode plate includes a first current collector exposed portion where a portion of the positive electrode current collector corresponding to an outermost portion of the electrode group is exposed over a length of greater than or equal to one turn in a winding direction of the electrode group, and a second current collector exposed portion where a portion of the positive electrode current collector corresponding to a middle portion of the electrode group is exposed over a length of greater than or equal to one turn in the winding direction. A positive electrode lead is provided on the second current collector exposed portion so as to be connected to an external electrode.

Nonaqueous electrolyte secondary cell

A battery packincluding a plurality of cells, in which the plurality of cellsare arranged so as to be oriented in the same direction, the cellseach have a first safety valve and a second safety valve whose operating pressure is higher than an operating pressure of the first safety valve, the first safety valve of each cellis connected to a first exhaust passage, the second safety valve of each cellis connected to a second exhaust passage, and the first exhaust passageis spatially separated from the second exhaust passage

In a charging method for a lithium ion battery, constant current charging of the lithium ion battery is performed. The constant current charging includes at least three consecutive charging stages. The at least three consecutive charging stages include consecutive first, second, and third charging stages. The second charging stage has a set current value which is set lower than set current values of the first and third charging stages.

Lithium ion battery charging method and battery-equipped device

In a rectangular battery, a leadL connected to an electrode plate having a first polarity is connected to a battery casewhich is an external terminal having the first polarity. A leadL connected to an electrode plate having a second polarity is connected to an external terminalhaving the second polarity, through a connection plate. A distance between the battery caseand the connection plateat at least one end of the battery casein a long-side direction is equal to or less than the half of the width of the battery casein a short-side direction thereof.

Rectangular battery

A battery pack comprising: a secondary battery including a safety valve; a gas absorption portion including a gas absorbent represented by zeolite and a container hermetically enclosing the gas absorbent; and a case housing the secondary battery and the gas absorption portion. The safety valve is configured to discharge a gas produced in the secondary battery at the time of abnormality. The container includes a principal surface facing the safety valve, for example, and when the gas is discharged, the container is unsealed by rupturing of at least the principal surface of the container by an effect of heat or pressure of the gas.

Battery pack including gas absorption portion

An electrode group formed by winding a positive electrode plate and a negative electrode plate with a separator interposed therebetween is housed in a battery case, and a sealing plate seals an opening of the battery case. The sealing plate includes an upper metal plate, a valve, and a lower metal plate that are stacked, an insulating plate is placed on a portion of the electrode group near the opening of the battery case, one of the positive electrode plate or the negative electrode plate of the electrode group is connected to the lower metal plate through a lead, the lower metal plate and the insulating plate have a first opening and a second opening, respectively, and a ratio of Sis within the range of 1.8-3.3, where Srepresents an area of the first opening, and Srepresents an area of the second opening.

Sealed secondary battery

A cooling unitis provided in the vicinity of a cell, and includes a sealed portionformed by sealing a sheet. An easy-to-open portionis provided in part of the sealed portion, and the easy-to-open portionis opened when the cellabnormally generates heat.

Battery module

Batteriesare accommodated in a case, wherein the batterieseach include an opening portionfor releasing gas produced in an associated one of the batteries to outside the battery, the caseis partitioned into an accommodation sectionconfigured to accommodate the batteriesand an exhaust passageconfigured to expel the gas released from at least one of the opening portionsof the batteriesto outside the case, the opening portionsof the batteriesare allowed to communicate with the exhaust passagethrough sealed connection passages, and a one-way open valvewhich is configured to open only along a direction from the opening portionof the batteryto the exhaust passageis provided in an intermediate portion or at an end of each of the connection passages

Cell module

Disclosed is a positive electrode for non-aqueous electrolyte secondary batteries, the positive electrode including a positive electrode material mixture layer which includes positive electrode active material particles and a binder. A curve representing a correlation between a distance from a current collector in the thickness direction of the positive electrode material mixture layer and an amount of the binder has a first maximum point, a minimum point, and a second maximum point. The minimum point corresponds to a position in a center area of the positive electrode material mixture layer in a thickness direction thereof, and the first and second maximum points correspond to a position nearer the current collector and a position further away from the current collector than the position corresponding to the minimum point, respectively. A ratio W/Wof an amount Wat the first maximum point to an amount Wat the minimum point of the binder per 100 parts by weight of the positive electrode active material particles is greater than 2.

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Osaka, Japan

Masato Fujikawa