A secondary battery that includes an electrode assembly; an exterior body defining a housing space that houses the electrode assembly; a positive electrode terminal that includes a first metal layer made of nickel and a second metal layer made of a metal other than nickel, the first metal layer of the positive electrode terminal is exposed from the exterior body, and the first metal layer has a fixing face; and an insulating material positioned so as to fix the fixing face of the first metal layer to an inner wall of the exterior body, and the insulating material abuts against a face of the positive electrode terminal other than the fixing face of the first metal layer.

A secondary battery that includes an electrode assembly; an exterior body defining a housing space that houses the electrode assembly; a positive electrode terminal that includes a first metal layer made of nickel and a second metal layer made of a metal other than nickel, the first metal layer of the positive electrode terminal is exposed from the exterior body, and the first metal layer has a fixing face; and an insulating material positioned so as to fix the fixing face of the first metal layer to an inner wall of the exterior body, and the insulating material abuts against a face of the positive electrode terminal other than the fixing face of the first metal layer.

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.

A battery cell may comprise: an electrode assembly, a housing and an end cap. The electrode assembly may have a first tab. The housing may have an opening for accommodating the electrode assembly. The end cap may be configured to connect with the housing and cover the opening. The end cap may have an abutting surface and a welding groove, the abutting surface may be configured to abut against the first tab, and the welding groove may be recessed from one side of the end cap away from the electrode assembly towards the abutting surface. The end cap may form a connector between the abutting surface and the bottom surface of the welding groove, and the connector is configured for being welded with the first tab. The end cap is provided with a reinforcing structure, and the reinforcing structure is protruded from the bottom surface.

A venting device for insertion into a sealing part of a pouch of a secondary battery includes: a housing configured to be inserted between two surfaces of the sealing part so as to be sealed together with the sealing part; a sheet disposed in the housing and defining a passage through which an inside and an outside of the pouch are configured to communicate with each other; a plate spring configured to open and close the passage according to an internal pressure of the pouch and made of a metal having elasticity; and a ball disposed between the sheet and the plate spring so as to contact or be spaced apart from the sheet at an outlet-side of the passage, thereby opening and closing the passage, wherein the ball has a hemispherical shape to be attached to an inner surface of the plate spring.

A venting device for insertion into a sealing part of a pouch of a secondary battery includes: a housing configured to be inserted between two surfaces of the sealing part so as to be sealed together with the sealing part; a sheet disposed in the housing and defining a passage through which an inside and an outside of the pouch are configured to communicate with each other; a plate spring configured to open and close the passage according to an internal pressure of the pouch and made of a metal having elasticity; and a ball disposed between the sheet and the plate spring so as to contact or be spaced apart from the sheet at an outlet-side of the passage, thereby opening and closing the passage, wherein the ball has a hemispherical shape to be attached to an inner surface of the plate spring.

A secondary battery includes a battery element including a positive electrode, a negative electrode, and an electrolytic solution, a housing member configured to accommodate the battery element, and a safety valve mechanism attached to the housing member. The safety valve mechanism includes a valve member including an opening valve portion configured to be opened; and an opening member including a plurality of opening portions radially arranged in a region opposed to the opening valve portion from a center of the region as a base point, and a plurality of protrusion portions radially arranged in a region outside the plurality of opening portions from the center and the plurality of protrusion portions protrude toward the plurality of opening portions. A number of the opening portions and a number of the protrusion portions are equal to each other, and each of the plurality of opening portions and each of the plurality of protrusion portions are opposed to each other in a direction toward the center.

An alkaline dry battery includes a battery case, a hollow cylindrical positive electrode accommodated in the battery case, a negative electrode disposed in the hollow portion of the positive electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolytic solution contained in the positive electrode, the negative electrode and the separator. The alkaline dry battery further includes a layer principally including a compound containing a polyoxyethylene group between the positive electrode and the inner surface of the battery case.

An alkaline dry battery includes a battery case, a hollow cylindrical positive electrode accommodated in the battery case, a negative electrode disposed in the hollow portion of the positive electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolytic solution contained in the positive electrode, the negative electrode and the separator. The alkaline dry battery further includes a layer principally including a compound containing a polyoxyethylene group between the positive electrode and the inner surface of the battery case.