A battery pack includes: a battery cell having a cell tab extending outwardly; a protection circuit module electrically connected to the cell tab to prevent over-charging and over-discharging of the battery cell; and a module case accommodating the protection circuit module and mounted on the battery cell, wherein the module case includes a first region, a second region positioned on the first region, and a third region extending from the first region through the second region, and the protection circuit module is accommodated in a cavity provided between the first region and the second region.

A secondary battery includes: an electrode assembly including a negative electrode plate, a positive electrode plate, and a separator between the negative electrode plate and the positive electrode plate; and a case accommodating the electrode assembly. The electrode assembly includes an adhesive part on an outermost region of the electrode assembly. The adhesive part is arranged to cover a boundary line between the negative electrode plate and the separator or between the positive electrode plate and the separator, and is bonded to the case.

A battery module includes: a plurality of cylindrical battery cells including a gas vent portion to discharge an internal gas; and a busbar plate including a plurality of connection terminals that protrude and extend from an inner edge of a connection opening, and to electrically connect the cylindrical battery cells by contacting a positive or negative electrode terminal, and have different shapes depending on the contacted positive or negative electrode terminal, and a connection terminal contacting a positive or negative electrode terminal not having the gas vent portion. The connection terminal includes: a fuse portion to be disconnected when a current of a predetermined level or higher flows from the cylindrical battery cells and having a bent structure bent; and a protection tube to contract at a predetermined temperature with electric insulation and to surround at least a portion of an outer surface of the fuse portion.

An electronic device (1) includes: a battery pack (10) that includes a battery cell housed inside an exterior member (30) so that a battery element (20) is movable in a movable direction (M); a housing (40) that houses the battery pack (10); and adhesive members (50) that bond the battery pack (10) inside the housing (40), in which the adhesive members (50) bond the battery pack (10) and the housing (40) on a second line (L2) where an angle formed with a first line (L1) parallel to the movable direction (M) is an acute angle and that passes through a center (10S) of the battery pack (10).

An electronic device (1) includes: a battery pack (10) that includes a battery cell housed inside an exterior member (30) so that a battery element (20) is movable in a movable direction (M); a housing (40) that houses the battery pack (10); and adhesive members (50) that bond the battery pack (10) inside the housing (40), in which the adhesive members (50) bond the battery pack (10) and the housing (40) on a second line (L2) where an angle formed with a first line (L1) parallel to the movable direction (M) is an acute angle and that passes through a center (10S) of the battery pack (10).

Disclosed is a rechargeable battery including: an electrode assembly wound with a separator between a first electrode and a second electrode; a first exterior material including an opening receiving the electrode assembly and facing a bottom side of the electrode assembly; a second exterior material covering the opening, and combined to the first exterior material to seal an internal side of the first exterior material; and a reinforcing member having greater rigidity than the first exterior material and the second exterior material, disposed between the electrode assembly and the first exterior material, and including a side wall for surrounding a lateral side of the electrode assembly.

A cell includes a first current collector and a second current collector. A tail end of the first current collector exceeds a tail end of the second current collector by at least half a circle in a winding direction. The inventor of the present application finds that after the length of the first current collector is increased, and the tail end of the first current collector exceeds the tail end of the second current collector by at least half a circle, the following situation may occur: the outermost circle of the cell is the first current collector, the secondary outer circle is the first current collector, and the next secondary outer circle is the second current collector, such that both the outermost circle and the secondary outer circle of the cell are the first current collector.

A cell includes a first current collector and a second current collector. A tail end of the first current collector exceeds a tail end of the second current collector by at least half a circle in a winding direction. The inventor of the present application finds that after the length of the first current collector is increased, and the tail end of the first current collector exceeds the tail end of the second current collector by at least half a circle, the following situation may occur: the outermost circle of the cell is the first current collector, the secondary outer circle is the first current collector, and the next secondary outer circle is the second current collector, such that both the outermost circle and the secondary outer circle of the cell are the first current collector.

A button-type secondary battery includes an electrode assembly in which a negative electrode, a separator, and a positive electrode are layered wound in a state of being layered; a lower can in which the electrode assembly is mounted, and a space portion is defined as a surplus space in addition to a space in which the electrode assembly is mounted; an upper can coupled to the lower can to close the lower can in a state in which the electrode assembly is mounted in the lower can, and an electrolyte is injected; and a swelling member mounted in the lower can in a state of being coupled to an outer surface of the electrode assembly. When the electrolyte is injected, the swelling member absorbs the electrolyte to be expanded in volume within the space portion.

A button-type secondary battery includes an electrode assembly in which a negative electrode, a separator, and a positive electrode are layered wound in a state of being layered; a lower can in which the electrode assembly is mounted, and a space portion is defined as a surplus space in addition to a space in which the electrode assembly is mounted; an upper can coupled to the lower can to close the lower can in a state in which the electrode assembly is mounted in the lower can, and an electrolyte is injected; and a swelling member mounted in the lower can in a state of being coupled to an outer surface of the electrode assembly. When the electrolyte is injected, the swelling member absorbs the electrolyte to be expanded in volume within the space portion.