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 secondary battery with a reduced degree of increase in internal pressure over time, is provided. In a preferred embodiment, a secondary battery including: an electrode body, a battery case, an electrode terminal, and a gasket sandwiched between the battery case and the electrode terminal is provided. The secondary battery is configured such ghat a parameter K calculated using the following equation (1): K=Wi/(VrG.sub.H2) (1) (where Wi represents an initial capacity (Ah) of the secondary battery, Yr represents a volume (cm.sup.3) of void in the battery case, and G.sub.H2, represents an H.sub.2 gas permeability coefficient (cm.sup.3.Math.cm)/(cm.sup.2.Math.s.Math.cmHg) of the gasket at 60° C.) satisfies 0.43×10.sup.8 or more to 0.59×10.sup.8 or less.

A secondary battery with a reduced degree of increase in internal pressure over time, is provided. In a preferred embodiment, a secondary battery including: an electrode body, a battery case, an electrode terminal, and a gasket sandwiched between the battery case and the electrode terminal is provided. The secondary battery is configured such ghat a parameter K calculated using the following equation (1): K=Wi/(VrG.sub.H2) (1) (where Wi represents an initial capacity (Ah) of the secondary battery, Yr represents a volume (cm.sup.3) of void in the battery case, and G.sub.H2, represents an H.sub.2 gas permeability coefficient (cm.sup.3.Math.cm)/(cm.sup.2.Math.s.Math.cmHg) of the gasket at 60° C.) satisfies 0.43×10.sup.8 or more to 0.59×10.sup.8 or less.

A device for manufacturing a battery cell according to one embodiment of the present disclosure includes a sealing tool that forms a sealing part on the outer peripheral surface of a battery case to which an electrode assembly is mounted, wherein the sealing tool comprises a sealing surface that is brought into contact with the outer peripheral surface of the battery case, and wherein the sealing surface comprises a central surface and an inclined surface formed on at least one side of the central surface.

A device for manufacturing a battery cell according to one embodiment of the present disclosure includes a sealing tool that forms a sealing part on the outer peripheral surface of a battery case to which an electrode assembly is mounted, wherein the sealing tool comprises a sealing surface that is brought into contact with the outer peripheral surface of the battery case, and wherein the sealing surface comprises a central surface and an inclined surface formed on at least one side of the central surface.

A storage battery sealing member includes a vulcanized rubber composition; the rubber composition contains a silicone rubber and a vulcanizing agent; a hardness Ha of the sealing member at 23° C. and a relative humidity of 50%, is 90 points or less; a compression set of the sealing member, measured after 25% compression followed by aging at 150° C. for 70 hours, is 80% or less; a difference between the hardness Ha of the sealing member at 23° C. and the relative humidity of 50% and a hardness Hb of the sealing member at 23° C. and the relative humidity of 50% after heated at 400° C. for 10 minutes is within 15 points; and a mass of a residue after heating the sealing member at 800° C. for 5 minutes, relative to the sealing member before heating, is 70 to 100% by mass.

A storage battery sealing member includes a vulcanized rubber composition; the rubber composition contains a silicone rubber and a vulcanizing agent; a hardness Ha of the sealing member at 23° C. and a relative humidity of 50%, is 90 points or less; a compression set of the sealing member, measured after 25% compression followed by aging at 150° C. for 70 hours, is 80% or less; a difference between the hardness Ha of the sealing member at 23° C. and the relative humidity of 50% and a hardness Hb of the sealing member at 23° C. and the relative humidity of 50% after heated at 400° C. for 10 minutes is within 15 points; and a mass of a residue after heating the sealing member at 800° C. for 5 minutes, relative to the sealing member before heating, is 70 to 100% by mass.

A terminal-equipped case member having an external terminal for electrically connecting an external device, which is fixed to a case body for housing an electronic component or a case member constituting a case lid attached to the case body, includes a base material made of metal that forms the case member; the external terminal inserted into a through hole formed through the base material; a sealing material formed of a first resin material that seals a gap between the external terminal and the base material; and a terminal adhesion layer. The external terminal and the sealing member are bonded to each other through the terminal adhesion layer formed of a second resin material with a higher adhesion to the external terminal than that of the first resin material.

A terminal-equipped case member having an external terminal for electrically connecting an external device, which is fixed to a case body for housing an electronic component or a case member constituting a case lid attached to the case body, includes a base material made of metal that forms the case member; the external terminal inserted into a through hole formed through the base material; a sealing material formed of a first resin material that seals a gap between the external terminal and the base material; and a terminal adhesion layer. The external terminal and the sealing member are bonded to each other through the terminal adhesion layer formed of a second resin material with a higher adhesion to the external terminal than that of the first resin material.

An adhesive film for metal terminals, which is capable of achieving high sealing performance between itself and a thermally fusible resin layer of an outer covering material in a short time, is interposed between a metal terminal that is electrically connected to an electrode of an electricity storage device element and an outer covering material for electricity storage devices. This adhesive film is configured from a multilayer body provided with: a first polyolefin layer; a base material; and a second polyolefin layer. The heat of fusion ΔH1 of the first polyolefin layer and the heat of fusion ΔH2 of the second polyolefin layer as determined in accordance with JIS K 7122 (2012) satisfy the relational expression ΔH1>ΔH2; and the heat of fusion ΔH3 of the base material as determined in accordance with JIS K 7122 (2012) is 70 J/g or more.