Hitachi Automotive Systems, Ltd.

Hitachi Vehicle Energy, Ltd.

Vehicle Energy Japan Inc.

Keisuke Sawada

Takuro Tsunaki

Kazuaki Urano

Kinya Aota

Naoki Kimura

Kouichi Kajiwara

Fujio Hirano

Takenori Ishizu

Sho Saimaru

Yutaka Sato

Mitsuru Koseki

Kiyoyuki Sekine

Hideyuki Shibanuma

Hidemasa Kawai

Ryuji Kono

Naoki Kojima

Masaaki Iwasa

Shou Saimaru

Provided is a secondary battery which is capable of more reliably cutting off current by increasing a deformation amount of a member, which is deformed by a rise of an internal pressure of a battery container and cuts off current. The secondary battery is provided with a current cut-off mechanism in a current path between an external terminal and an electrode inside a battery container. The current cut-off mechanism is accommodated in the battery container, and is provided with a diaphragm connected to the external terminal and a current collector connected to the electrode. The diaphragm is disposed on an outer side of the battery container than the current collector and has a convex shape toward an inside of the battery container. The current collector includes a concave portion on a surface facing the outer side of the battery container, and the diaphragm is bonded to the concave portion.

Secondary battery

A secondary battery includes a diaphragm which is disposed on a current path between a current collector plate connected to a wound electrode group in a battery container and an external terminal, deforms when an internal pressure of the battery container increases, and breaks the current path. The diaphragm has a convex portion which protrudes to the current collector plate. The current collector plate has a through-hole into which the convex portion is inserted. An inner wall portion of the through-hole and a side wall portion of the convex portion facing each other are welded.

Provided is a secondary battery which can more securely suppress vibrations applied to a current interrupting mechanism. A secondary battery including: a current interrupting mechanism that interrupts a current path between an external terminal and an electrode in a battery container. The current interrupting mechanism includes a collector plate that is connected to the electrode, a diaphragm that is connected to a base portion of the collector plate and disconnected from the base portion by being deformed when a pressure in the battery container is increased, and an insulating member that fixes the diaphragm and the base portion of the collector plate on the inside of the battery container. The insulating member includes a plurality of projections that protrude in a thickness direction of the base portion, and the base portion includes a plurality of notches through which the projection passes in the thickness direction. The projection includes an engaging member that is engaged with an end surface of the base portion on a side opposite to the insulating member and a side surface of the base portion along the thickness direction.

A rectangular secondary battery () includes a current interrupting portion () disposed in a current path between a collector plate () connected to a rolled electrode group () and an external terminal () disposed outside a battery container () and configured to interrupt the current path when an internal pressure of the battery container () is increased. The current interrupting portion () has a diaphragm () electrically connected to the external terminal () and deformed when the internal pressure of the battery container () is increased, a connection plate () connected to the diaphragm and disconnected from the diaphragm by the deformation of the diaphragm, and a connecting portion () connecting the connection plate and collector plate. A rigidity of the connecting portion () is lower than that of the collector plate ().

Rectangular secondary battery

A rectangular secondary battery () includes a current interrupting portion () disposed in a current path between a collector plate () connected to a rolled electrode group () and an external terminal () and configured to interrupt the current path when an internal pressure of a battery container () is increased. The current interrupting portion () has a diaphragm () whose top portion () is electrically connected to the collector plate () and whose edge portion () is electrically connected to the external terminal (). The diaphragm () is formed into a convex shape protruding inside the battery container () and into a planar shape elongated in a longitudinal direction of the battery container ().

Battery

Growing community of inventors

Hitachinaka, Japan

Keisuke Sawada