Other

Toyo Kohan Co., Ltd.

Akiyoshi Takada

Kinji Saijo

Kazuo Yoshida

Yoshihiko Isobe

Nobuyuki Yoshimoto

Akira Takagi

A closed battery which is capable of rapidly releasing the internal pressure there while simultaneously disconnecting the current to prevent the internal temperature of the battery from rising and causing the battery to explode. Thus, when the internal pressure of the closed battery is elevated due to a short circuit, overcharge, reverse charge, or the like, internal gas in the battery can be safely discharged and the battery prevented from bursting.

Closed battery

The object of the present invention is to provide an explosion-proof safety valve assemblage having a lead cap which allows some of the manufacturing man-hour in the process such as precision working and positioning to be deleted, since the lead cap is integrally formed with an explosion-proof safety valve and serves to provide a current circuit in a battery in place of a conventional one composed of lead plate or lead wire which requires such precision working and positioning operations, and to provide a closed secondary battery using the above mentioned safety valve assemblage. An explosion-proof safety valve assemblage for use in a closed secondary battery comprising an outer container, an electrode element, consisting of a positive electrode, negative electrode, and a separator, accommodated in said outer container, wherein said safety valve assemblage is sealingly secured to an open end portion of said outer container via an insulating gasket integrally with a closing cap, and it consists of an explosion-proof safety valve element, a coreless disc-shaped insulator, and a lead cap formed of a metal substrate and a metal foil laminated to the metal substrate, substantially the center of which is provided with an opening, and a closed secondary battery using the above mentioned safety valve assemblage.

Explosion-proof safety valve assemblage for a secondary battery

Hermetically sealed cell

The object of the present invention is to provide a closed battery capable of rapidly releasing the internal pressure thereof and at the same time disconnecting the current to effectively prevent itself from temperature rising and exploding so that in such a completely closed battery it may assure the safety and reliability thereof, when the internal pressure is elevated due to short circuit, overcharge, reverse charge, or the like. A valve element is provided with a slit between the circumference thereof and a metal substrate . When the internal pressure of a battery is elevated, the valve element is smoothly raised up together with a metal foil from a bending fulcrum portion to thereby cut a lead wire or permit a braze portion to detach from the lead wire , thus disconnecting the current reliably. Then, the metal foil which usually closes the slit formed around the circumference of the valve element is allowed to burst stably and accurately at a prescribed pressure to thereby form a valve opening portion so that the internal gas of the battery can be discharged.

Closed battery and closing member

The object of the present invention is to provide a closed battery capable of rapidly releasing the internal pressure thereof and at the same time disconnecting the current to effectively prevent itself from temperature rising and explosion so that it may assure the safety and reliability thereof, when the internal pressure is elevated due to short circuit, overcharge, reverse charge, or the like in such a completely closed battery. The formation of a valve element,whose center is eccentric to the center of a metal substrate,produces a slit,having a large width portion around the circumference of a valve element,. When the internal pressure of a battery is elevated, the valve element,is smoothly raised up together with a metal foil,from the bending fulcrum portion,to thereby cut a lead wire,or permit a braze portion,to detach from the lead wire,, thus reliably disconnecting the current. Then, the metal foil is allowed to burst stably and accurately at a prescribed pressure to thereby form a valve opening portion,so that the internal gas of the battery can be discharged. Thus, the battery can previously be prevented from exploding.

Hermetically sealed cell and sealing body

A safety valve element for battery use which ruptures at a stable pressure range so as to release the inner pressure of the battery is disclosed. The safety valve element for battery use comprises a metal substrate which is provided with a perforated opening and a metal foil laminated on the metal substrate so as to close the perforated opening. A battery which is provided with such a safety valve is also disclosed. A battery case provided with such a safety valve is also disclosed. The battery and the battery case lid is produced by forming the perforated opening in the metal substrate, pressure welding the metal foil to the metal substrate and molding the clad material into a form of the battery case lid.

Growing community of inventors

Shiga-ken, Japan

Akiyoshi Takada