Provided is a secondary battery including an electrode assembly and an exterior body that houses the electrode assembly. In the secondary battery, the exterior body includes a metal plate joined via an insulating material interposed therebetween, and the exterior body has a cavity, and one of a peripheral edge of the cavity and an outer edge of the metal plate is bent so as to be separated from the insulating material.

Provided is a secondary battery including an electrode assembly and an exterior body that houses the electrode assembly. In the secondary battery, the exterior body includes a metal plate joined via an insulating material interposed therebetween, and the exterior body has a cavity, and one of a peripheral edge of the cavity and an outer edge of the metal plate is bent so as to be separated from the insulating material.

A secondary battery with favorable cycle performance is provided. Alternatively, a secondary battery with higher capacity is provided. A positive electrode active material layer including a first graphene layer, a second graphene layer, and a positive electrode active material. The first graphene layer includes a first region covering the positive electrode active material. The second graphene layer includes a second region covering the positive electrode active material and a third region overlapping with the first region. The first region includes a plane positioned between the positive electrode active material and the third region and formed of arranged six-membered carbon rings. The positive electrode active material includes a fourth region with a layered rock-salt structure. A lithium layer with a layered rock-salt structure included in the fourth region is substantially perpendicular to the plane formed of six-membered carbon rings and included in the second region.

Provided is a secondary battery including an electrode assembly and an exterior body that houses the electrode assembly. In the secondary battery, the exterior body includes a metal plate joined via an insulating material interposed therebetween, and the exterior body has a cavity, and one of a peripheral edge of the cavity and an outer edge of the metal plate is bent toward the insulating material.

Provided is a secondary battery including an electrode assembly and an exterior body that houses the electrode assembly. In the secondary battery, the exterior body includes a metal plate joined via an insulating material interposed therebetween, and the exterior body has a cavity, and one of a peripheral edge of the cavity and an outer edge of the metal plate is bent toward the insulating material.

A button-type secondary battery including an electrode assembly having a first and second electrode tabs; a lower can having an accommodation part, in which the electrode assembly is accommodated and to which the first electrode tab is connected, and a flange part on an outer circumferential surface of the accommodation part; an upper cap on the accommodation part covering the accommodation part and a curl part on an outer circumferential surface of the cover part; a terminal member coupled to the upper cap and connected to the second electrode tab; and an insulating member configured to insulate the terminal member and the upper cap from each other and seal a gap between the terminal member and the upper cap. The flange part and the curl part are coupled to each other in a seaming manner to seal a gap between the lower can and the upper cap.

A button-type secondary battery including an electrode assembly having a first and second electrode tabs; a lower can having an accommodation part, in which the electrode assembly is accommodated and to which the first electrode tab is connected, and a flange part on an outer circumferential surface of the accommodation part; an upper cap on the accommodation part covering the accommodation part and a curl part on an outer circumferential surface of the cover part; a terminal member coupled to the upper cap and connected to the second electrode tab; and an insulating member configured to insulate the terminal member and the upper cap from each other and seal a gap between the terminal member and the upper cap. The flange part and the curl part are coupled to each other in a seaming manner to seal a gap between the lower can and the upper cap.

A rechargeable battery according to an embodiment of the present invention 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 opening in one side and receiving the electrode assembly; and a cap assembly combined to the opening and closing and sealing the case, wherein the cap assembly includes a cap plate combined to the opening and including a terminal hole, a terminal plate combined to the top of the cap plate to cover the terminal hole, an upper insulator disposed at the top of the cap plate to be provided between the cap plate and the terminal plate, and a lower insulator disposed at a bottom of the cap plate and including an edge disposed near the case and extending downward.

A rechargeable battery according to an embodiment of the present invention 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 opening in one side and receiving the electrode assembly; and a cap assembly combined to the opening and closing and sealing the case, wherein the cap assembly includes a cap plate combined to the opening and including a terminal hole, a terminal plate combined to the top of the cap plate to cover the terminal hole, an upper insulator disposed at the top of the cap plate to be provided between the cap plate and the terminal plate, and a lower insulator disposed at a bottom of the cap plate and including an edge disposed near the case and extending downward.

The invention relates to a button lithium ion battery, a preparation method thereof, and a method of producing a lithium ion cell composite flat sheet, wherein the button lithium ion battery comprises a battery housing, a cell accommodated in the battery housing and an electrolyte filled in the battery housing; the cell is formed by winding a composite flat sheet in which a first separator, a positive piece, a second separator and a negative piece are sequentially stacked and hot-laminated to form an integrated structure. The cell of the button lithium ion battery is formed by winding a composite flat sheet, so that winding efficiency can be improved, and misalignment can be avoided; moreover, chances of hand contact can be reduced, the influence of dust and water vapor can be avoided, and the quality of the lithium battery can be improved to the maximum extent.