US 8,283,061 B2Granted

Film-encased electric device and production method therefor

AssigneeNEC Corporation

InventorsMakihiro Otohata, Hiroshi Yageta

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Abstract

A releasing pressure and a pressure releasing position, when enclosing films are expanded by gas produced at an abnormal time, are easily and positively configured. A film-enclosed battery (1) has a battery element (2) and two enclosing films (4, 5) for sealing the battery element (2). The enclosing films (4, 5) include heat-sealable resin layers and air-impermeable layers, and the heat-sealable resin layers and air-impermeable layers, and the heat-sealable resin layers that are face each other hold the battery element (2) and seal the battery element (2) when their peripheral edges are thermally fused. A cross-linking structure (8) formed by cross-linking heat-sealable resin layer is formed in one of the enclosing films (4, 5) so that a region in part of a heat-sealed area (6) has a position exposed to a battery element housing unit and another portion in contact with outside air.

Claims20

Dependent claims

A film-encased electric device comprising:

an electric device element having a positive pole tab and a negative pole tab connected thereto;
encasing films having at least respective heat-sealable resin layers and which surround said electric device element with the heat-sealable resin layers that face each other, the facing heat-sealable resin layers being thermally fused to each other along outer peripheral regions thereof to provide a heat-sealed area therealong, said encasing films having an inner space therebetween that serves as an electric device element housing which accommodates said electric device element sealed therein, with said positive pole tab and said negative pole tab extending from said electric device element;
and
a pressure releaser disposed in a portion of said heat-sealed area on a side from which said positive pole tab and said negative pole tab extend, between said positive pole tab and said negative pole tab, or on a side different from the side from which said positive pole tab and said negative pole tab extend, said pressure releaser being arranged to allow said thermally fused encasing films to peel off progressively more preferentially therein than other regions due to internal pressure buildup in said electric device element housing;
said pressure releaser having a cross-linked structure made of a cross-linked resin with a lower peel strength than the rest of the heat-sealed area and disposed in a continuous region in which said cross-linked structure has a portion exposed to said electric device element housing and another portion held in contact with ambient air.

2 more elements

A method of manufacturing a film-encased electric device having an electric device element that has a positive pole tab and a negative pole tab connected thereto and surrounded by encasing films having at least respective heat-sealable resin layers and having respective outer peripheral regions thermally fused to each other to provide a heat-sealed area, said encasing films having an inner space therebetween serving as an electric device element housing which accommodates said electric device element sealed therein, with said positive pole tab and said negative pole tab extending from said electric device element, said method comprising the steps of:

forming a cross-linked structure made of a cross-linked resin in a continuous region including a portion of said heat-sealed area of the encasing films, on a side of at least one of said encasing films from which said positive pole tab and said negative pole tab extend, between said positive pole tab and said negative pole tab, or on a side different from the side from which said positive pole tab and said negative pole tab extend, said cross-linked structure having a portion exposed to said electric device element housing and another portion held in contact with ambient air;
surrounding said electric device element between said encasing films with said cross-linked structure formed therein, said heat-sealable resin layers facing each other around said electric device element, with said positive pole tab and said negative pole tab extending from said electric device element;
and
thermally fusing the outer peripheral regions of said encasing films which surround said electric device element sandwiched therebetween to seal said electric device element, thereby forming a pressure releaser in a region including the region in which said cross-linked structure is formed, for allowing said thermally fused encasing films to peel off progressively more preferentially therein than other regions due to internal pressure buildup in said electric device element housing,
wherein said cross-linked structure has a lower peel strength than the remainder of the thermally fused encasing films.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/573,538Filed 5 Aug 2005
Priority: JP 2004-23452411 Aug 2004
Published: US 2008/0233468 A125 Sep 2008
Granted: 9 Oct 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

H01G 9/08
Details: housing; Encapsulation
H01G 2/08
Details of capacitors not covered by a single one of groups H01G4/00-H01G11/00: cooling arrangements; Heating arrangements; Ventilating arrangements
H01G 2/103
Housing; Encapsulation: sealings, e.g. for lead-in wires; Covers
H01G 9/12
Housing; Encapsulation: vents or other means allowing expansion