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 cylindrical secondary battery includes: an electrode assembly including a positive electrode plate having a positive electrode multi-tab, a separator, and a negative electrode plate having a negative electrode multi-tab, the positive electrode plate, the separator, and the negative electrode plate being laminated and wound; a cylindrical can accommodating the electrode assembly; a cap plate coupled at an upper end of the cylindrical can and being electrically connected to the negative electrode multi-tab; and a positive electrode terminal protruding upwardly through the cap plate and being electrically connected to the positive electrode multi-tab.

A housing part for an electrical device, which is an electrical storage device, a sensor housing, a battery, a microbattery, or a capacitor, the housing part including: a feedthrough, the housing part or a base body which is a part of the housing part including the feedthrough, the feedthrough having at least one opening, the at least one opening having a wall with a reduced enclosure length EL.sub.red, the at least one opening configured for receiving a conductive material or a conductor in a glass material or a glass-ceramic material, the reduced enclosure length EL.sub.red being in a range of 0.05 mm to 0.6 mm, 0.1 mm to 0.5 mm, 0.1 mm to 0.4 mm, or 0.15 mm to 0.2 mm.

A collector plate assembly includes a collector plate and a collector plate support, the collector plate having a welding part for welding to a terminal of a battery unit, and the collector plate being installed in the collector plate support in such a way that the welding part is exposed by the collector plate support. A battery pack includes a housing; a battery support, enclosed by the housing and supported in the housing, the battery support being electrically connectable to an electric tool to supply electric power to the electric tool; and a collector plate assembly including a collector plate support and a collector plate installed in the collector plate support.

A secondary battery includes an outer package member, an electrode terminal, and a battery device. The outer package member has a flat and columnar shape and includes a first bottom part and a second bottom part opposed to each other. The electrode terminal is supported by the first bottom part and is insulated from the first bottom part. The battery device is contained inside the outer package member and includes a first electrode and a second electrode. The first bottom part has a recess around the electrode terminal.

A secondary battery includes an outer package member, a battery device, and an insulating member. The outer package member has a flat and columnar shape and includes a first bottom part and a second bottom part opposed to each other. The battery device is contained inside the outer package member, and has a first through hole extending from the first bottom part toward the second bottom part. The insulating member is adhered in part to the battery device between the second bottom part and the battery device, and has a second through hole at a position overlapping with the first through hole.

A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a case including an inner space accommodating the electrode assembly, and an opening; a cap plate coupled to the case at the opening and including a terminal hole exposing the inner space; an electrode terminal electrically connected to the electrode assembly through the terminal hole and overlapping the cap plate; electrode tabs respectively connected to the first electrode and the second electrode; and an electrolyte solution in the inner space, and at least one electrode tab of the electrode tabs has an inclined portion that is inclined at a first angle with respect to a surface of the electrode assembly facing the at least one electrode tab.

A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a case configured to be connected to the first electrode and accommodate the electrode assembly, and including an opening to expose the electrode assembly; a cap plate configured to be coupled to the case to cover an outer area of the opening, and including a through-hole to expose a central area of the opening; a terminal plate configured to cover the through-hole and to be connected to the second electrode; and a thermal-fusion layer configured to be arranged between the cap plate and the terminal plate and to insulation-bond the cap plate and the terminal plate, and the thermal-fusion layer includes a plurality of layers including a thermoplastic resin layer.

Provided are a cover assembly for a battery and a battery. The cover assembly for the battery includes an elastic cover, an insulating cover, a frame support member and a terminal column assembly. The insulation cover is embedded in one end of the elastic cover. The frame support member has a greater hardness than the elastic cover and the insulating cover. The frame support member is embedded in the other end of the elastic cover. The elastic cover has an encapsulation portion disposed on an outside, in a radical direction, of the insulating cover and the frame support member. The encapsulation portion is in a cylindrical shape and configured to abut against an inner surface of a housing of the battery. The terminal assembly includes a terminal penetrating the insulating cover and the elastic cover.

A secondary battery includes: a case member; a cover member having a through-hole and configured to close an opening of the case member; a terminal member passed through the through-hole; and a sealing member configured to close a gap between the cover member and the terminal member. The sealing member includes: an exposed end portion placed to be exposed inside the case member; and an extending portion extending from the exposed end portion toward the position of the through-hole. The cover member includes a first surface portion. The terminal member includes a second surface portion placed to face the first surface portion via a distance. The first surface portion and the second surface portion are placed to compress the extending portion. The distance between the first surface portion and the second surface portion increases toward the position of the exposed end portion.