Laminated battery and manufacturing method therefor
A laminated battery provided with an electricity-producing element and an outer case. The electricity-producing element contains a positive electrode, a negative electrode, and an electrolyte. The outer case comprises two sheets of laminating film and includes the following: a containing section that contains the electricity-producing element; and a sealing section that is formed around the edge of the containing section by bonding the sheets of laminating film to each other. Corners are formed along the boundary between the containing section and the sealing section, and an adhesive resin layer in the sealing section is thicker in corner regions near the aforementioned corners than in other regions.
1. A laminated battery comprising:
a power generation element having a cathode, an anode, and an electrolyte; and
an outer structure formed by two laminated films each including an adhesive resin layer, the outer structure having a storage unit for the power generation element, and a sealing section formed at a periphery of the storage unit by joining the films, wherein
a corner is formed at a boundary between the storage unit and the sealing section,
in the sealing section, a thickness of the adhesive resin layer in a direction perpendicular to an adhesive surface of the adhesive resin layer at a corner region proximate the corner is greater than a thickness of the adhesive resin layer in the direction perpendicular to the adhesive surface of the adhesive resin layer at the other regions, and
a portion of the adhesive resin layer having the greater thickness is formed to surround the corner,
wherein in the corner region of the sealing section, a plurality of protrusions are formed on at least one of the laminated films,
wherein each of the protrusions is formed in a string form from a side of the storage unit toward the outside.
2. The laminated battery according to claim 1 , wherein
the storage unit is provided by forming in advance a depression that can store the power generation element on one of the laminated films, and
the protrusion is formed only on the laminated film having the depression.
3. The laminated battery according to claim 1 , wherein
a thickness of the adhesive resin layer in the direction perpendicular to the adhesive surface of the adhesive resin layer at a recess positioned between the protrusions is greater than a thickness of the adhesive resin layer in the direction perpendicular to the adhesive surface of the adhesive resin layer at the other regions.
4. The laminated battery according to claim 1 , wherein
a thickness of the adhesive resin layer in the direction perpendicular to the adhesive surface of the adhesive resin layer at the protrusion is less than or equal to three times the thickness of the adhesive resin layer in the direction perpendicular to the adhesive surface of the adhesive resin layer at the other regions.
5. A method of manufacturing a laminated battery having a power generation element having a cathode, an anode, and an electrolyte, and an outer structure formed by two laminated films each including an adhesive resin layer, the method comprising:
a first step in which a depression that becomes a storage unit for the power generation element is formed through a drawing process and by pressing at least one of the laminated films with a pressing jig in which a through hole is formed; and
a second step in which, after the power generation element is stored in the depression, a sealing section is formed at a periphery of the storage unit by joining the laminated films, wherein
in the first step, a load applied at a portion proximate a corner of the through hole is set smaller than a load at the other portions when a load is applied to the pressing jig, to form a plurality of protrusions at a region, of a portion that becomes the sealing section, proximate a corner formed at a boundary with the depression, so that a thickness of the adhesive resin layer in a direction perpendicular to an adhesive surface of the adhesive layer at the region is set greater than a thickness of the adhesive resin layer in the direction perpendicular to the adhesive surface of the adhesive layer at the other regions and a portion of the adhesive layer having the greater thickness is formed to surround the corner,
wherein the plurality of protrusions are formed on at least one of the laminated films,
wherein each of the protrusions is formed in a string form from a side of the storage unit toward the outside.