In an embodiment, a battery includes a container, a lid member, an electrode group, an electrode terminal and an electrode group retainer. The lid member is attached to a peripheral wall of the container with an opening of an inner cavity being closed. The electrode terminal is electrically connected to the current collecting tab. The electrode group retainer is arranged between the electrode group and the lid member. A proximity plate portion of the electrode group retainer is close to the electrode group from a side where the lid member is located and forms a space between the lid member and thereof. A facing surface of the proximity plate portion is formed to have a shape that is along an outer surface of an end portion of the electrode group on a side where the lid member is located.

In an embodiment, a battery includes a container, a lid member, an electrode group, an electrode terminal and an electrode group retainer. The lid member is attached to a peripheral wall of the container with an opening of an inner cavity being closed. The electrode terminal is electrically connected to the current collecting tab. The electrode group retainer is arranged between the electrode group and the lid member. A proximity plate portion of the electrode group retainer is close to the electrode group from a side where the lid member is located and forms a space between the lid member and thereof. A facing surface of the proximity plate portion is formed to have a shape that is along an outer surface of an end portion of the electrode group on a side where the lid member is located.

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 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 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 secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a case including a first side having an opening to accommodate the electrode assembly; a cap plate sealing the first side of the case; a first current collector plate arranged between the electrode assembly and the cap plate and electrically connecting the first electrode plate and the cap plate; a terminal arranged on a second side of the case; a second current collector plate electrically connecting the second electrode plate and the terminal; a first welding portion on an outer surface of the cap plate and welding the cap plate and the first current collector plate; and a second welding portion on the outer surface of the cap plate and welding the case and the cap plate.

A secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a case including a first side having an opening to accommodate the electrode assembly; a cap plate sealing the first side of the case; a first current collector plate arranged between the electrode assembly and the cap plate and electrically connecting the first electrode plate and the cap plate; a terminal arranged on a second side of the case; a second current collector plate electrically connecting the second electrode plate and the terminal; a first welding portion on an outer surface of the cap plate and welding the cap plate and the first current collector plate; and a second welding portion on the outer surface of the cap plate and welding the case and the cap plate.

A battery module includes a cell stack including a plurality of battery cells that are electrically connected to one another; a module housing accommodating the cell stack therein and including a pair of module holes formed in one surface; and a pair of venting hole terminals each including terminal hole communicating with the module hole, and electrically connected to the cell stack.

A battery module includes a cell stack including a plurality of battery cells that are electrically connected to one another; a module housing accommodating the cell stack therein and including a pair of module holes formed in one surface; and a pair of venting hole terminals each including terminal hole communicating with the module hole, and electrically connected to the cell stack.

An adhesive film for metal terminals is interposed between a metal terminal connected to an electrode of a power storage device element and a power storage device external member, and includes, a first polyolefin layer, a substrate, and a second polyolefin layer disposed on the metal terminal side. A sea-island structure is observed in a sectional image of the first polyolefin layer in a direction parallel to TD, the sectional image being obtained in the range of up to 30% of the thickness of the first polyolefin layer. In the sectional image, after the adhesive film for metal terminals is left to stand for 12 seconds in a heated and pressurized environment in which the temperature is 190° C. and the surface pressure is 0.016 MPa, and then left for one hour at 25° C., the of the total area of the island portions of the sea-island structure is 25.0% to 35.0%.