Toyota Jidosha Kabushiki Kaisha

Sanyo Electric Co., Ltd.

Hiroshi Inukai

Yasuhiro Yamauchi

Toshihiro Takada

Yoshinori Yokoyama

Hironori Harada

Akira Kiyama

Toshiyuki Nohma

Takayuki Hattori

Eiji Okutani

Ryuta Morishima

Naoya Nakanishi

Yasushi Tsuchida

Takuichi Arai

Naoya Tada

Takashi Tokunaga

Yoshiya Maruyama

A prismatic secondary battery of one configuration has a current disconnection mechanism, and a distance from a first conductive member to a second conductive member along a surface of a first insulation member and passing an outer periphery of the first insulation member is greater than or equal to 2.4 mm. At least one of the first insulation member and a second insulation member is formed from a material having a weight reduction percentage of 100% in thermo gravimetric measurement under conditions of a measurement temperature of 25&#xb0; C.-600&#xb0; C., a temperature increase rate of 5&#xb0; C.&#xb1;0.5&#xb0; C./min, a measurement atmosphere of inert gas flow, and an amount of measurement sample of 10 mg&#xb1;5 mg.

Prismatic secondary battery having spark prevention mechanism and battery pack using the same

Provided is a sealed battery with improved safety and reliability in which no spark discharge or voltage recovery occurs after a current interrupt mechanism has been actuated. A sealed batteryincludes a current interrupt mechanism: having an inversion plateand a collector. The collectorand the inversion plateare electrically and mechanically joined in the easily breakable sectionand the inversion section, the easily breakable sectionis broken and displaced together with the inversion sectionby the displacement of the inversion section, and the electric connection of the collectorand the inversion plateis interrupted. The distance between the collectorand the easily breakable sectionafter the displacement is within a range of 0.3 mm to 1.5 mm.

Sealed battery including current interrupting mechanism

Provided is a sealed secondary battery having a current interrupt mechanism with a high heat resistance that prevents fusion of the current collecting plate by the Joule heat generated during high-rate charge and discharged. A current interrupt mechanismof a sealed secondary batteryprovided in accordance with the present invention is configured such that when the internal pressure inside a battery caserises above the predetermined level, a current interrupt valveis deformed by the internal pressure in a direction of separating from a rectangular plate-shaped current collecting plateand the current collecting plate breaks in the portion of an annular grooveof a central thin sectionof the current collecting plate.

Sealed secondary battery

A current interruption mechanism for prismatic secondary battery includes a tubular conductive member electrically connected to a positive electrode external terminal, an inversion plate, and a positive electrode collector connected to the inversion plate. The positive electrode collector has a first region that is parallel to a sealing body and a second region that is connected to a positive electrode plate. The boundaries between the first and second regions are disposed further outward than the inner surface of the tubular conductive member, and at least one of the edge portions, other than the boundaries between the first region and second region, is located further outward than the inner surface of the tubular portion of the conductive member. The current interruption mechanism is unlikely to be damaged even if the battery is subjected to shock due to vibration, falling, etc.

Prismatic secondary battery

A high-reliability prismatic secondary battery with a current interruption mechanism that is unlikely to be damaged even if the battery is subjected to shock is provided. The prismatic secondary battery includes a second insulating member having a first through-hole, the second insulating member being arranged between a first region of a positive electrode collector and an inversion plate. The first region of the positive electrode collector and the inversion plate are electrically connected to each other through the first through-hole. The second insulating member has a plurality of fixing pawl portions. The fixing pawl portions are hooked and fixed to a fixing portion formed on the outer surface side of the conductive member.

A crimped portion of a positive electrode external terminal is crimped on its upper end side to be electrically connected to a positive electrode terminal plate. This crimped portion is welded to the positive electrode terminal plate by applying high energy beams. The negative electrode side has a configuration similar to that of the positive electrode side. The contact area between the positive electrode terminal plate and the crimped portion of the positive electrode external terminal is set smaller than the corresponding contact area on the negative electrode side, and the volume of the crimped portion of the positive electrode external terminal is set larger than that of the corresponding crimped portion on the negative electrode side. Thus, a prismatic secondary battery is provided that shows strong joining strength between the external terminal and the terminal plate, suppressed internal resistance variations, and improved reliability.

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Toyota, Japan

Hiroshi Inukai