The present disclosure provides a sealing plate including a gas release vent capable of suppressing scattering of a metallic fragment during activation. A gas release vent of a sealing plate disclosed herein includes: a base portion with a flat plate shape; a thin portion which is thinner than the base portion; a groove portion formed in the thin portion; and a valve element formed inside the groove portion. In addition, the groove portion has a remaining portion which is a region with a larger remaining thickness as compared to another region of the groove portion. The remaining portion of the groove portion is formed in a region including one intersection point among two intersection points where a straight line which passes a center of the gas release vent and which extends in a short-side direction of the sealing plate intersects the groove portion with the approximately annular shape.

Embodiments of the present application provide an insulating film and related devices. The insulating film is configured to wrap a battery assembly, the insulating film includes a bottom coverage area, N side coverage areas and N pairs of bonding areas; the bottom coverage area has N sides, the N side coverage areas are respectively connected to the bottom coverage area outside the N sides, and can be respectively bend toward the bottom coverage area along the N sides; each pair of the N pairs of bonding areas is located between two adjacent side coverage areas, and is connected to the two adjacent side coverage areas respectively; each pair of bonding areas is configured to make the bottom coverage area and the N sides coverage areas form a space wrapping the battery assembly by bonding surfaces on the same side of each pair of bonding areas.

Embodiments of the present application provide an insulating film and related devices. The insulating film is configured to wrap a battery assembly, the insulating film includes a bottom coverage area, N side coverage areas and N pairs of bonding areas; the bottom coverage area has N sides, the N side coverage areas are respectively connected to the bottom coverage area outside the N sides, and can be respectively bend toward the bottom coverage area along the N sides; each pair of the N pairs of bonding areas is located between two adjacent side coverage areas, and is connected to the two adjacent side coverage areas respectively; each pair of bonding areas is configured to make the bottom coverage area and the N sides coverage areas form a space wrapping the battery assembly by bonding surfaces on the same side of each pair of bonding areas.

A rechargeable battery includes: a case receiving an electrode assembly and including an opening; a cap assembly including a cap plate coupled to the case to cover the opening, and a terminal plate thermally fused to the cap plate by a thermal-fusion member, the thermal-fusion member electrically insulating the cap plate and the terminal plate from each other; and a sealing part attached to and located on a side of the thermal-fusion member, a side surface of the terminal plate, and an outer surface of the cap plate.

A rechargeable battery includes: a case receiving an electrode assembly and including an opening; a cap assembly including a cap plate coupled to the case to cover the opening, and a terminal plate thermally fused to the cap plate by a thermal-fusion member, the thermal-fusion member electrically insulating the cap plate and the terminal plate from each other; and a sealing part attached to and located on a side of the thermal-fusion member, a side surface of the terminal plate, and an outer surface of the cap plate.

A rechargeable battery includes: an electrode assembly including a first electrode tab and a second electrode tab; a case including an opening and receiving the electrode assembly to be connected to the first electrode tab; a cap assembly including a cap plate coupled to the case and covering the opening, and a terminal plate coupled to the cap plate and connected to the second electrode tab; a first insulating member between the second electrode tab and the cap plate; a second insulating member attached to a surface of the second electrode tab; and a third insulating member between the second electrode tab and the electrode assembly.

A rechargeable battery includes: an electrode assembly including a first electrode tab and a second electrode tab; a case including an opening and receiving the electrode assembly to be connected to the first electrode tab; a cap assembly including a cap plate coupled to the case and covering the opening, and a terminal plate coupled to the cap plate and connected to the second electrode tab; a first insulating member between the second electrode tab and the cap plate; a second insulating member attached to a surface of the second electrode tab; and a third insulating member between the second electrode tab and the electrode assembly.

The present invention provides a cylindrical secondary battery which can have increased safety and capacity, and enhanced scratch resistance and pressure resistance on an external contact surface. To this end, a cylindrical secondary battery is disclosed, the battery comprising: a cylindrical case; an electrode assembly received in the case; and a cap assembly for sealing the case, wherein the cap assembly comprises a top plate having a notch formed on at least one surface thereof, a middle plate coupled to the top plate and including a first through-hole formed through the center thereof, and a bottom plate electrically connected with the electrode assembly and coupled to the top plate through the first through-hole of the middle plate, and includes a surface-treated region formed by surface-treating a surface of the top plate so as to have a concave-convex structure.

A battery cell has a case accommodating an electrode assembly; an electrode lead protruding from the case at front and rear ends of the case; a first sealing part formed at both side ends of the case; a second sealing part connecting the first sealing part at a portion in which the electrode lead is formed; a first cut surface formed by cutting the first sealing part; a second cut surface formed by cutting the second sealing part; and an insulating member covering the sealing parts and the cut surfaces, wherein the first sealing part is bent in a direction of a first surface of the case, and a main portion of the insulating member is attached in a shape surrounding the first sealing part and the first cut surface, and wherein a side surface portion of the insulating member surrounds the second sealing part and the second cut surface.

A battery cell includes an electrode assembly formed by stacking a first separator, a negative electrode plate, a second separator, and a positive electrode plate; a negative electrode tab protruding from the negative electrode plate; and a positive electrode tab protruding from the positive electrode plate, the first and second separators have larger size in all four surfaces than the negative and positive electrode plates, and the whole of the tab edge portions of the first and second separators located on the surface on which the positive electrode tab and the negative electrode tab are formed and a part of the both side edge portions connected to the tab edge portion are adhered to each other, the inward adhesion width at the tab edge portion is smaller than the inward adhesion width at both ends where the tab edge portion and the both side edges portions are connected.