A power storage device includes a case, a power storage element disposed in the case, a lead connected to an electrode of the power storage element, a sealing member sealing an opening of the case. The sealing member includes a gasket and a sealing plate having conductivity. The gasket includes a base having a disk shape. The base is disposed between the sealing plate and the power storage element. The base has a through-hole formed therein. The sealing plate includes a protrusion inserted in the through-hole. The protrusion of the sealing plate is connected to the lead. The protrusion is configured to be displaced in a direction away from the lead in accordance with an increase of an internal pressure of the case so as to be disconnected from the lead.

A power storage device includes a case, a power storage element disposed in the case, a lead connected to an electrode of the power storage element, a sealing member sealing an opening of the case. The sealing member includes a gasket and a sealing plate having conductivity. The gasket includes a base having a disk shape. The base is disposed between the sealing plate and the power storage element. The base has a through-hole formed therein. The sealing plate includes a protrusion inserted in the through-hole. The protrusion of the sealing plate is connected to the lead. The protrusion is configured to be displaced in a direction away from the lead in accordance with an increase of an internal pressure of the case so as to be disconnected from the lead.

An embodiment of the present invention relates to a cylindrical secondary battery comprising: a cylindrical can having a bottom surface and a side portion extending from the bottom surface, one end of the side portion being open to form an opening; an electrode assembly accommodated in the can; and a cap assembly including a gasket which is inserted into the can with the electrode assembly inserted in the can to come into contact with the electrode assembly, and a cap plate which is disposed on the gasket and is electrically connected to the electrode assembly, wherein the can has, at the edge of the opening, a curling portion which presses the gasket to bring the gasket into contact with the cap plate.

A technical object to be solved according to the present disclosure is to provide a secondary battery which has reduced electrical resistance by directly connecting an electrode assembly to a can and/or a terminal without lead tabs and also has an increased battery capacity by removing lead tabs. To this end, the present disclosure provides a secondary battery comprising: a can; an electrode assembly accommodated in the can and including a first uncoated portion extending in a first direction and a second uncoated portion extending in a second direction opposite to the first direction; a first current collector plate electrically connected to the first uncoated portion of the electrode assembly; a first terminal portion coupled to the can and electrically connected to the first current collector plate; and a second terminal portion coupled to the can and electrically connected to the second uncoated portion of the electrode assembly.

A secondary battery includes: an electrode assembly; a case accommodating the electrode assembly, the case having an opening at a first end sized to accommodate the electrode assembly and a terminal hole at a second end opposite to the first end; a first current collector plate coupled to the electrode assembly; a terminal electrically coupled to the first current collector plate and extending through the terminal hole in the case; and a cap plate sealing the opening of the case.

A secondary battery includes: an electrode assembly; a case accommodating the electrode assembly, the case having an opening at a first end sized to accommodate the electrode assembly and a terminal hole at a second end opposite to the first end; a first current collector plate coupled to the electrode assembly; a terminal electrically coupled to the first current collector plate and extending through the terminal hole in the case; and a cap plate sealing the opening of the case.

A secondary battery includes: an electrode assembly; a case accommodating the electrode assembly; a cap plate sealing the case; and a current collector plate welded between the electrode assembly and the case or between the electrode assembly and the cap plate. The current collector plate has a slit therein.

A secondary battery includes: an electrode assembly; a case accommodating the electrode assembly; a cap plate sealing the case; and a current collector plate welded between the electrode assembly and the case or between the electrode assembly and the cap plate. The current collector plate has a slit therein.

A secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a can having a closed upper surface with a rivet opening therein and an open lower surface to accommodate the electrode assembly, the can being electrically connected to the first electrode plate; a rivet terminal in the rivet opening and electrically connected to the second electrode plate; a gasket between the can and the rivet terminal; and a cap plate sealing the lower surface of the can.

Provided is a secondary battery. The secondary battery includes a can, an electrode assembly in the can, a collector plate electrically connected to the electrode assembly, and a terminal having a coupling part mechanically coupled to the collector plate by a pressure, electrically connected to the collector plate, and electrically connected to the electrode assembly.