JP2018006242A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack capable of being miniaturized, and having enough durability.SOLUTION: A battery pack 10 comprises: a plurality of electric cells 2; and a battery outer packaging for packaging each electric cell 2. Facing conductive sheets 31 and 32 form a plurality of cylindrical parts 35 divided by adhesive parts 31A and 32A, a battery housing part 5 is ensured in an inner part of each cylindrical part 35. Each cylindrical part 35 is formed by an intermediate part of the conductive sheets 31 and 32. The intermediate part includes a flexure form of which at least one part is convexly formed to an outer direction. The electric cell 2 comprises: a positive electrode collector 51; a positive active material layer 52; a negative electrode collector 53; a negative active material layer 54; a separator 55; and an electrolyte 56. The electric cell is provided in each of the plurality of battery housing parts 5. The positive electrode collector 51 is conductively contacted with the conductive sheet 31. The negative electrode collector 53 is conductively contacted to the conductive sheet 32.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an assembled battery.

As environmental awareness increases, secondary batteries such as lithium ion batteries are attracting attention as storage batteries for storing electrical energy.
As an exterior container that accommodates a battery, a container made of a laminate sheet in which a metal foil and a resin layer are laminated is used in order to reduce the size and weight (for example, see Patent Document 1).

JP 2000-357494 A

For example, in a storage battery for an electric vehicle or the like, an assembled battery configured by connecting a plurality of single cells is used to increase the capacity. For example, there is an assembled battery having a structure in which a plurality of single cells in a container in which a battery is housed in an exterior container are connected.
The assembled battery is required to be small and durable, but it has not been easy to achieve both miniaturization and improved durability. For example, if the structure of the assembled battery is simplified for downsizing, the durability is lowered. If a protective structure is provided to increase durability, it is difficult to reduce the size of the assembled battery.

  One embodiment of the present invention has been made in view of the above-described situation, and an object thereof is to provide an assembled battery which can be downsized and has sufficient durability.

In order to solve the above-described problem, one embodiment of the present invention includes a plurality of single cells and a battery outer body that covers the single cells, and the battery outer body includes a plurality of conductor sheets, Among the conductor sheets, at least a pair of the conductor sheets facing each other are partially bonded at a plurality of linear bonding portions, and the plurality of bonding portions are formed apart from each other in the width direction orthogonal to the length direction. The pair of opposing conductor sheets form a plurality of cylindrical portions partitioned by the adhesive portion, a battery accommodating portion is secured inside the cylindrical portion, and at least one of the pair of conductor sheets Is formed continuously in the width direction over the plurality of cylindrical portions, and the cylindrical portion is formed by an intermediate portion between the adjacent adhesive portions of the conductor sheet, The middle part Each of the unit cells has a bent shape in which at least a part is convex outward, the positive electrode current collector, a positive electrode active material layer in contact with the positive electrode current collector, a negative electrode current collector, and the negative electrode A negative electrode active material layer in contact with the current collector, a separator separating the positive electrode active material layer and the negative electrode active material layer, and an electrolyte, each provided in the plurality of battery housing portions, Provided is an assembled battery in which one of the pair of conductor sheets abuts electrically and the negative electrode current collector abuts on the other of the pair of conductor sheets.
The intermediate portions of the pair of conductor sheets extend at an incline with respect to the substrate portion so as to approach the opposite conductor sheet toward the widening direction from both side edges of the substrate portion and the substrate portion, respectively. It is preferable that the cylindrical part is formed in a hexagonal cylindrical shape by the substrate part and the side plate part of the pair of conductor sheets.
The conductive sheet having a plurality of sets of the pair of conductive sheets, both surfaces of which are bonded to the other conductive sheet, the bonding portion of which one surface is bonded to the other conductive sheet; It is preferable that the other portion of the adhesive portion bonded to the other conductor sheet is alternately arranged in the width direction.
Of the bonded portion in which the one surface is bonded to the other conductive sheet and the bonded portion in which the other surface is bonded to the other conductive sheet, one is formed wider than the other. It is preferable that
Among the plurality of sets of the conductive sheets facing each other in the thickness direction, a space is secured between one set of the conductive sheets facing each other and the other set of the conductive sheets facing each other. preferable.
It is preferable that a sealing plate for closing one and the other openings of the cylindrical portion is provided at both ends of the battery exterior body in the adhesive portion length direction.
It is preferable that the sealing plate is in contact with the opening of the cylindrical portion via a seal member.
It is preferable that the sealing plate that closes one opening of the cylindrical portion and the sealing plate that closes the other opening are fixed to the battery exterior body by a fastening fixture.
It is preferable that the conductor sheet has a metal layer, and the metal layer faces the battery housing portion.
The metal layer is preferably a metal foil containing one or more of aluminum, copper, stainless steel, nickel, and iron.
The conductor sheet is a laminate further including a resin layer, and the resin layer preferably includes one or more of polyester, polyamide, polyimide, polyolefin, acrylic resin, polyurethane, fluororesin, and thermosetting resin. .
The conductor sheet is preferably bonded by a polyolefin-based adhesive at the bonding portion.

According to one aspect of the present invention, since the plurality of battery housing portions are formed of a common conductor sheet, compared to an assembled battery using a plurality of exterior body containers that individually wrap a single cell, for example, connection Since a part of the structure can be omitted, the structure can be simplified. Therefore, the battery pack can be reduced in size and weight.
Moreover, since the positive electrode current collector and the negative electrode current collector of the unit cell are connected to the conductor sheet, the conductor sheet can function as a terminal. Therefore, the structure of the unit cell can be simplified, and the assembled battery can be further reduced in size and weight.

In one embodiment of the present invention, since a plurality of battery housing portions are formed of a common conductor sheet, the mechanical strength is higher than that of an assembled battery using a plurality of outer packaging containers that individually wrap single cells. Is excellent. For example, damage is unlikely to occur when a tensile force in the width direction of the conductor sheet, a shearing force in the length direction of the bonded portion, or a shearing force in the thickness direction is applied. Moreover, since it has the some cylindrical part formed in a row by the common conductor sheet, durability with respect to the compressive force of the adhesion part length direction can be improved.
Therefore, according to one embodiment of the present invention, reduction in size and weight can be achieved, and sufficient durability can be provided.
Since one embodiment of the present invention has a simple structure, it can be formed in a plurality of stages without complicating the structure. Therefore, an assembled battery in which a plurality of single cells are connected not only in parallel but also in series can be configured. Therefore, a variety of assembled batteries can be provided in accordance with the purpose of use, such as battery capacity and voltage.

It is sectional drawing which shows the assembled battery of 1st Embodiment typically. It is sectional drawing which shows typically the battery exterior body used for the assembled battery of FIG. It is a circuit diagram of the assembled battery of FIG. It is a perspective view which shows the assembled battery of 2nd Embodiment typically. It is a disassembled perspective view which shows the structure of the assembled battery of a previous figure typically. It is a side view which shows typically the modification of the assembled battery of FIG. It is explanatory drawing which shows the manufacturing process of the assembled battery of FIG. It is explanatory drawing which shows the manufacturing process following a previous figure. It is sectional drawing which shows typically the example of the assembled battery using the 1st modification of the battery exterior body of embodiment. It is sectional drawing which shows typically the example of the assembled battery using the 2nd modification of the battery exterior body of embodiment. It is sectional drawing which shows typically the 1st modification of the cylindrical part of the battery exterior body of embodiment. It is sectional drawing which shows typically the 2nd modification of the cylindrical part of the battery exterior body of embodiment. It is sectional drawing which shows typically the 3rd modification of the cylindrical part of the battery exterior body of embodiment. It is sectional drawing which shows typically the assembled battery using the example of a battery exterior body.

  Hereinafter, the present invention will be described based on preferred embodiments.

[Battery] (first embodiment)
FIG. 1 is a cross-sectional view schematically showing an assembled battery 10 that is the assembled battery of the first embodiment. FIG. 2 is a cross-sectional view schematically showing the battery outer package 1.
The assembled battery 10 includes a battery outer package 1 and a plurality of single cells 2.
The battery outer package 1 includes a plurality of conductor sheets 3. The battery outer package 1 shown in FIGS. 1 and 2 includes, for example, four conductor sheets 3 arranged in the overlapping direction. These four conductor sheets 3 are also referred to as first to fourth conductor sheets 31, 32, 33, and 34 in order from the top.

As shown in FIG. 2, the conductor sheet 3 (31, 32, 33, 34) is a laminated body in which a metal layer 6 and a resin layer 7 are laminated, and has flexibility.
In the conductor sheet 3, the metal layer 6 is a configuration necessary for ensuring the conductive performance. The conductor sheet 3 may be composed of only the metal layer 6, but preferably has a resin layer 7 in order to ensure insulation.

The metal constituting the metal layer 6 may be, for example, aluminum, copper, stainless steel, nickel, iron, or an alloy including one or more of these. The metal layer 6 is a metal foil containing one or more of aluminum, copper, stainless steel, nickel, and iron, for example. The metal may be carbon steel that is an iron alloy. In particular, aluminum foil, copper foil, and stainless steel foil are preferable from the viewpoints of workability, availability, price, strength (such as piercing strength and tensile strength), and corrosion resistance.
The metal layer 6 may have a structure having a base metal layer and a plating layer formed on the surface thereof. The base metal layer and the plating layer are made of, for example, the aforementioned metals.

The stainless steel foil is made of stainless steel such as austenite, ferrite, and martensite. Examples of austenite include SUS304, 316, 301, etc., ferrite include SUS430, and martensite includes SUS410.
The metal layer 6 has a function of reducing leakage of liquid from the battery housing portion 5, for example.

The thickness of the metal layer 6 is preferably 1 mm or less, more preferably 500 μm or less, and most preferably 200 μm or less from the viewpoint of improving the workability of the conductor sheet 3. The thickness of the metal layer 6 is preferably 5 μm or more, more preferably 20 μm or more, and most preferably 40 μm or more from the viewpoint of increasing the mechanical strength of the conductor sheet 3. In addition, the upper limit value and lower limit value in the numerical range can be arbitrarily combined.
When a metal layer (O material) softened by annealing is used as the metal layer 6, the flexible performance is improved, and the conductor sheet 3 can be easily formed in the shape described later.

  In the assembled battery 10 shown in FIGS. 1 and 2, the metal layer 6 of the first conductor sheet 31 and the third conductor sheet 33 is preferably made of aluminum or an alloy thereof. It is preferable that the metal layer 6 of the 2nd conductor sheet 32 and the 4th conductor sheet 34 consists of copper or its alloy. The metal layer 6 of the conductor sheets 32 and 34 may have a structure in which a nickel plating layer is formed on the surface of a base metal layer made of copper or an alloy thereof.

The resin layer 7 is, for example, a polyolefin resin such as expanded polypropylene (OPP); a polyester resin such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polybutylene terephthalate (PBT); a polyamide resin such as nylon (Ny); It consists of one or more of polyimide resin; fluororesin; acrylic resin; thermosetting resin-based paint (thermosetting resin); polyurethane resin. Of these, OPP and thermosetting resin-based paints are preferable from the viewpoint of durability.
The thickness of the resin layer 7 is preferably 200 μm or less, more preferably 100 μm or less, and most preferably 50 μm or less from the viewpoint of improving the workability of the conductor sheet 3. From the viewpoint of increasing the mechanical strength of the conductor sheet 3, the thickness of the resin layer 7 is preferably 1 μm or more, and more preferably 10 μm or more.

The resin layer 7 may have a single layer structure or a multilayer structure. Examples of the resin layer 7 having a multilayer structure include a two-layer film in which a PET film and a biaxially stretched polyamide resin film (ONy) are laminated. The resin layer 7 may have a multilayer structure of three or more layers.
The resin layer 7 may be provided with a desired color or design by containing a colorant such as a pigment.
The conductor sheet 3 has a posture in which the metal layer 6 faces the battery housing portion 5.

1 and 2, the X direction is the width direction of the conductor sheet 3. The Y direction is a direction orthogonal to the X direction in a plane along the conductor sheet 3 (for example, the substrate portion 31C). The Z direction is a direction orthogonal to the X direction and the Y direction, and is the thickness direction of the conductor sheet 3.
Of the conductor sheets 31, 32, 33, 34, the first and second conductor sheets 31, 32 are a pair of conductor sheets 3 arranged to face each other. The conductor sheets 31 and 32 are referred to as the first set 30A of conductor sheets 3.
The third and fourth conductor sheets 33 and 34 are a pair of conductor sheets 3 disposed to face each other. The conductor sheets 33 and 34 are referred to as the second set 30B of conductor sheets 3. The first set 30A and the second set 30B are adjacent to each other in the thickness direction (Z direction).

The first conductor sheet 31 and the second conductor sheet 32 are partially bonded by a plurality of linear adhesive layers 4 (adhesive layers 41). The adhesive layer 41 is formed by laminating an adhesive layer 41A formed on the lower surface 31a (opposing surface) of the conductor sheet 31 and an adhesive layer 41B formed on the upper surface 32b (opposing surface) of the conductor sheet 32. Configured.
The adhesive layers 41 </ b> A and 41 </ b> B are formed, for example, in a band shape having a constant width along the Y direction. The adhesive layers 41A and 41B have the same width and are formed to overlap each other. The plurality of adhesive layers 41 are formed apart from each other in the X direction. The plurality of adhesive layers 41 are preferably formed at regular intervals in the X direction.

A portion of the first conductor sheet 31 that is adhered to the second conductor sheet 32 by the adhesive layer 41 is referred to as an adhesive portion 31A. The adhesion part 31A is, for example, a band-shaped part having a constant width along the Y direction. The plurality of adhesive portions 31A are formed apart from each other in the X direction. The plurality of adhesive portions 31A are preferably formed at a constant interval in the X direction.
A portion of the second conductor sheet 32 that is adhered to the first conductor sheet 31 by the adhesive layer 41 is referred to as an adhesive portion 32A. The bonding part 32A is, for example, a band-shaped part having a constant width along the Y direction. The plurality of adhesive portions 32A are formed apart from each other in the X direction. The plurality of bonding portions 32A are preferably formed at regular intervals in the X direction.

The second conductor sheet 32 and the third conductor sheet 33 are partially bonded by a plurality of linear adhesive layers 42.
The adhesive layer 42 is formed between the lower surface 32 a (opposing surface) of the conductor sheet 32 and the upper surface 33 b (opposing surface) of the conductor sheet 33.
The adhesive layer 42 is formed, for example, in a band shape having a constant width along the Y direction. The plurality of adhesive layers 42 are formed apart from each other in the X direction. The plurality of adhesive layers 42 are preferably formed at regular intervals in the X direction.

A portion of the second conductor sheet 32 that is bonded to the third conductor sheet 33 by the adhesive layer 42 is referred to as an adhesive portion 32B. The bonding portion 32B is, for example, a band-shaped portion having a constant width along the Y direction. The plurality of bonding portions 32B are formed apart from each other in the X direction. The plurality of bonding portions 32B are preferably formed at a constant interval in the X direction.
A portion of the third conductor sheet 33 bonded to the second conductor sheet 32 by the adhesive layer 42 is referred to as an adhesive portion 33B. The bonding portion 33B is, for example, a band-shaped portion having a constant width along the Y direction. The plurality of bonding portions 33B are formed apart from each other in the X direction. The plurality of bonding portions 33B are preferably formed at a constant interval in the X direction.

In the second conductor sheet 32, an adhesive portion 32A in which the upper surface 32b (first surface) is adhered to the first conductor sheet 31 and an adhesion in which the lower surface 32a (second surface) is adhered to the third conductor sheet 33. The portions 32 </ b> B are alternately arranged in the width direction (X direction) of the second conductor sheet 32.
The bonding part 32B is preferably formed wider than the bonding part 32A.

The third conductor sheet 33 and the fourth conductor sheet 34 are partially bonded by a plurality of linear adhesive layers 43.
The adhesive layer 43 is formed by laminating an adhesive layer 43A formed on the lower surface 33a (opposing surface) of the conductor sheet 33 and an adhesive layer 43B formed on the upper surface 34b (opposing surface) of the conductor sheet 34. Configured.
The adhesive layers 43A and 43B are formed, for example, in a band shape having a constant width along the Y direction. The adhesive layers 43A and 43B have the same width and are formed to overlap each other. The plurality of adhesive layers 43 are formed apart from each other in the X direction. The plurality of adhesive layers 43 are preferably formed at regular intervals in the X direction.

Examples of the adhesive constituting the adhesive layers 41, 42, 43 include polyolefin adhesives, urethane adhesives, epoxy adhesives, acrylic adhesives, urethane adhesives, nylon adhesives, and polyester adhesives. An insulating material such as an agent can be given.
The adhesive is preferably a polyolefin-based adhesive made of a polyolefin resin. Examples of the polyolefin resin include polyethylene, polypropylene, poly-1-butene, polyisobutylene, a copolymer of propylene and ethylene, a copolymer of propylene and an olefin monomer, and the like. Of these, maleic anhydride-modified polypropylene is preferable from the viewpoints of adhesion, durability, and the like. Moreover, it is preferable that the crosslinking agent contains a compound containing a plurality of epoxy groups. More specifically, an adhesive containing an acid-modified polyolefin resin (for example, maleic anhydride-modified polypropylene) (A) and an epoxy resin compound (B) can be used. The adhesive containing the acid-modified polyolefin resin (A) and the epoxy resin compound (B) is preferable from the viewpoint of strength in bonding, and a high-strength exterior body can be manufactured. The epoxy resin compound (B) preferably has, for example, two or more epoxy groups in one molecule, and is an adhesive containing 1 to 30% of bisphenol type phenol A type epoxy resin or phenol novolac modified epoxy resin. Is more preferable.

By using a polyolefin-based adhesive as the adhesive constituting the adhesive layers 41, 42, and 43, the adhesive strength of the conductor sheet 3 can be increased, and the battery outer package 1 having excellent strength can be obtained. .
When the adhesive contains an acid-modified polyolefin resin and a cross-linking agent, the battery outer package 1 having high adhesive strength and excellent durability of the conductor sheet 3 can be manufactured.

A portion of the third conductor sheet 33 bonded to the fourth conductor sheet 34 by the adhesive layer 43 is referred to as an adhesive portion 33A. The bonding portion 33A is, for example, a band-shaped portion having a constant width along the Y direction. The plurality of adhesive portions 33A are formed apart from each other in the X direction. The plurality of adhesive portions 33A are preferably formed at a constant interval in the X direction.
A portion of the fourth conductor sheet 34 that is adhered to the third conductor sheet 33 by the adhesive layer 43 is referred to as an adhesive portion 34A. The bonding portion 34A is, for example, a band-shaped portion having a constant width along the Y direction. The plurality of bonding portions 34A are formed apart from each other in the X direction. The plurality of adhesive portions 34A are preferably formed at a constant interval in the X direction.

In the third conductor sheet 33, an adhesive portion 33A in which the lower surface 33a (first surface) is adhered to the fourth conductor sheet 34 and an adhesion in which the upper surface 33b (second surface) is adhered to the second conductor sheet 32. The portions 33 </ b> B are alternately arranged in the width direction (X direction) of the third conductor sheet 33.
The bonding portion 33B is preferably formed wider than the bonding portion 33A.

As shown in FIG. 2, the portion of the first conductor sheet 31 between the adhering portions 31 </ b> A and 31 </ b> A adjacent in the X direction is referred to as an intermediate portion 31 </ b> E (non-adhering portion). The intermediate portion 31E includes a substrate portion 31C and a pair of side plate portions 31D and 31D that are inclined with respect to the substrate portion 31C. The substrate portion 31C faces one surface (upper surface in FIG. 1) of the unit cell 2 (2A) in the battery housing portion 5 (5A).
The side plate portions 31D and 31D extend from both side edges of the substrate portion 31C toward the bonding portions 31A and 31A, respectively. The side plate portions 31D and 31D are inclined and extended so as to gradually approach the second conductor sheet 32 (the counterpart conductor sheet 3) in the widening direction from both side edges of the substrate portion 31C. The side plate portions 31 </ b> D and 31 </ b> D are separated from each other as the second conductive sheet 32 is approached.
The intermediate portion 31E has a bent shape that is convex in a direction away from the second conductor sheet 32 (outward) with respect to a plane passing through the adjacent adhesive portions 31A and 31A.

The bonding portion 32B of the second conductor sheet 32 is also referred to as a substrate portion 32C. The substrate portion 32C faces the other surface (the lower surface in FIG. 1) of the unit cell 2 (2A) in the battery housing portion 5 (5A). The substrate portion 31C of the conductor sheet 31 and the substrate portion 32C of the conductor sheet 32 are separated in the thickness direction (Z direction).
Of the second conductor sheet 32, portions extending from both side edges of the substrate portion 32C toward the bonding portions 32A and 32A are referred to as side plate portions 32D and 32D. The side plate portions 32D and 32D are inclined and extended so as to gradually approach the first conductor sheet 31 (the counterpart conductor sheet 3) in the widening direction from both side edges of the substrate portion 32C. The side plate portions 32 </ b> D and 32 </ b> D are separated from each other as they approach the first conductor sheet 31.
A portion of the second conductor sheet 32 including the substrate portion 32C and the pair of side plate portions 32D and 32D is referred to as an intermediate portion 32E (non-adhesive portion). The intermediate part 32E is a part between the adhering parts 32A and 32A adjacent in the X direction.
The intermediate portion 32E includes a substrate portion 32C and side plate portions 32D and 32D that are inclined with respect to the substrate portion 32C. The intermediate portion 32E has a bent shape that protrudes in a direction away from the first conductor sheet 31 (outward) with respect to a plane passing through the adjacent adhesive portions 32A and 32A.

The side plate portions 31D and 31D of the intermediate portion 31E of the first conductor sheet 31 approach the second conductor sheet 32 in the widening direction, and the side plate portions 32D and 32D of the intermediate portion 32E of the second conductor sheet 32 are The first conductor sheet 31 approaches the widening direction. Therefore, the cylindrical portion 35 (35A) has a hexagonal cylindrical shape composed of the substrate portions 31C and 32C and the side plate portions 31D, 31D, 32D, and 32D.
One intermediate portion has a substrate portion and a pair of side plate portions inclined so as to approach the mating conductor sheet in the widening direction, and the other intermediate portion faces the substrate portion and the widening direction. And having a pair of side plate portions inclined so as to approach the mating conductor sheet, the shape constituted by these substrate portions and side plate portions can be called a hexagonal cylindrical shape.

It is desirable that the intermediate portions 31E and 32E of the conductor sheets 31 and 32 have a small difference in width dimension. For example, the difference in the width dimension of the intermediate portions 31E and 32E is preferably 10% or less, for example, with respect to the larger dimension of the width dimensions of the intermediate portions 31E and 32E.
The width dimension of the intermediate part 31E of the conductor sheet 31 is preferably equal to the width dimension of the intermediate part 32E of the conductor sheet 32.
The width dimension of the intermediate part 31E is the sum of the width dimensions of the substrate part 31C and the side plate parts 31D and 31D. The width dimension of the intermediate part 32E is the total of the width dimensions of the substrate part 32C and the side plate parts 32D, 32D.
The width dimensions of the substrate portions 31C and 32C are dimensions in a direction along the substrate portions 31C and 32C and orthogonal to the bonding portions 31A and 32A. The width dimensions of the side plate portions 31D and 32D are dimensions in a direction along the side plate portions 31D and 32D and orthogonal to the bonding portions 31A and 32A.

The bonding portion 33B of the third conductor sheet 33 is also referred to as a substrate portion 33C. The board portion 33C faces one surface (upper surface in FIG. 1) of the unit cell 2 (2B) in the battery housing portion 5 (5B).
Of the third conductor sheet 33, portions extending from both side edges of the substrate portion 33C toward the bonding portions 33A and 33A are referred to as side plate portions 33D and 33D. The side plate portions 33D and 33D are inclined and extended so as to gradually approach the fourth conductor sheet 34 (the counterpart conductor sheet 3) in the widening direction from both side edges of the substrate portion 33C. The side plate portions 33 </ b> D and 33 </ b> D are separated from each other as the fourth conductive sheet 34 is approached.
A portion of the third conductor sheet 33 including the substrate portion 33C and the pair of side plate portions 33D and 33D is referred to as an intermediate portion 33E (non-adhesive portion). The intermediate portion 33E is a portion between the adhesive portions 33A and 33A adjacent in the X direction.
The intermediate portion 33E includes a substrate portion 33C and side plate portions 33D and 33D that are inclined with respect to the substrate portion 33C. The intermediate portion 33E has a bent shape that is convex in a direction away from the fourth conductor sheet 34 (outward) with respect to a plane that passes through the adjacent adhesive portions 33A and 33A.

A portion of the fourth conductor sheet 34 between the adhering portions 34A and 34A adjacent in the X direction is referred to as an intermediate portion 34E (non-adhering portion). The intermediate portion 34E includes a substrate portion 34C and a pair of side plate portions 34D and 34D inclined with respect to the substrate portion 34C. The board portion 34C faces one surface (the lower surface in FIG. 1) of the unit cell 2 (2B) in the battery housing portion 5 (5B). The substrate portion 33C of the conductor sheet 33 and the substrate portion 34C of the conductor sheet 34 are separated in the thickness direction (Z direction).
The side plate portions 34D and 34D extend from both side edges of the substrate portion 34C toward the bonding portions 34A and 34A, respectively. The side plate portions 34D, 34D are inclined and extended so as to gradually approach the third conductor sheet 33 (the counterpart conductor sheet 3) in the widening direction from both side edges of the substrate portion 34C. The side plate portions 33 </ b> D and 33 </ b> D are separated from each other as the third conductive sheet 33 is approached.
The intermediate portion 34E has a bent shape that is convex in a direction away from the third conductor sheet 33 (outward) with respect to a plane passing through the adjacent adhesive portions 34A and 34A.
In FIG. 2, the substrate portions 31C, 32C, 33C, and 34C are formed along the XY plane.

  The side plate portions 33D and 33D of the intermediate portion 33E of the third conductor sheet 33 approach the fourth conductor sheet 34 in the widening direction, and the side plate portions 34D and 34D of the intermediate portion 34E of the fourth conductor sheet 34 are The third conductor sheet 33 is approached in the widening direction. Therefore, the cylindrical portion 35 (35B) has a hexagonal cylindrical shape composed of the substrate portions 33C, 34C and the side plate portions 33D, 33D, 34D, 34D.

It is desirable that the intermediate portions 33E and 34E of the conductor sheets 33 and 34 have a small difference in width dimension. For example, the difference in the width dimension between the intermediate portions 33E and 34E is preferably 10% or less, for example, with respect to the larger dimension of the width dimensions of the intermediate portions 33E and 34E.
The width dimension of the intermediate portion 33E of the conductor sheet 33 and the width dimension of the intermediate portion 34E of the conductor sheet 34 are preferably equal.
The width dimension of the intermediate portion 33E is the total width dimension of the substrate portion 33C and the side plate portions 33D and 33D. The width dimension of the intermediate portion 34E is the total width dimension of the substrate portion 34C and the side plate portions 34D and 34D.
The width dimensions of the substrate portions 33C and 34C are dimensions in a direction along the substrate portions 33C and 34C and orthogonal to the bonding portions 33A and 34A. The width dimensions of the side plate portions 33D and 34D are dimensions in a direction along the side plate portions 33D and 34D and orthogonal to the bonding portions 33A and 34A.

  The intermediate portion 31E (substrate portion 31C and side plate portions 31D and 31D) of the first conductor sheet 31 and the intermediate portion 32E (substrate portion 32C and side plate portions 32D and 32D) of the second conductor sheet 32 are hollow corners. A cylindrical tubular portion 35 (35A) is formed. The internal space of the cylindrical portion 35 (35A) is the battery accommodating portion 5 (5A). The cylindrical portion 35 (35A) is partitioned by adhesive portions 31A and 32A.

The side plate portions 31D and 31D have a flat shape in which the XZ cross section is linear, and are inclined at an angle θ1 (0 ° <θ1 <90 °) with respect to the substrate portion 31C. The side plate portions 32D and 32D have a flat shape in which the XZ cross section is linear, and are inclined at an angle θ2 (0 ° <θ2 <90 °) with respect to the substrate portion 32C.
The conductor sheets 31 and 32 are both formed continuously in the width direction over a plurality of cylindrical portions 35 (35A).

  The intermediate portion 33E (substrate portion 33C and side plate portions 33D, 33D) of the third conductor sheet 33 and the intermediate portion 34E (substrate portion 34C and side plate portions 34D, 34D) of the fourth conductor sheet 34 are hollow corners. A cylindrical tubular portion 35 (35B) is formed. The internal space of the cylindrical part 35 (35B) is the battery accommodating part 5 (5B). The cylindrical portion 35 (35B) is partitioned by bonding portions 33A and 34A.

The side plate portions 33D and 33D have a flat shape in which the XZ section is linear, and are inclined at an angle θ3 (0 ° <θ3 <90 °) with respect to the substrate portion 33C. The side plate portions 34D and 34D have a flat shape in which the XZ section is linear, and are inclined at an angle θ4 (0 ° <θ4 <90 °) with respect to the substrate portion 34C.
The angle θ3 may be the same as the angle θ1. The angle θ4 may be the same as the angle θ2. The angles θ1 to θ4 may be the same angle.
The conductor sheets 33 and 34 are both formed continuously in the width direction over a plurality of cylindrical portions 35 (35B).
The substrate portions 31C, 32C, 33C, and 34C have a flat shape in which, for example, the XZ section is linear.
The cylindrical portion 35 is a hexagonal cylindrical shape having flat side plate portions 31D, 32D, 33D, and 34D, and thus is a particularly preferable configuration in terms of strength of the assembled battery 10.

The side plate portions 32D and 32D and the bonding portion 32A of the second conductor sheet 32 and the side plate portions 33D and 33D and the bonding portion 33A of the third conductor sheet 33 have a plurality of hollow rectangular tube shapes (in FIG. 1, hexagonal tubes). A cylindrical portion 37 is formed.
Since the bonding part 32A is narrower than the bonding part 32B and the bonding part 33A is formed narrower than the bonding part 33B, the internal space 38 of the cylindrical part 37 is an internal space of the cylindrical part 35. The width dimension is smaller than the part 5.
The internal space 38 of the cylindrical portion 37 is a space secured between the first set 30A and the second set 30B. A heat medium (for example, cooling water or cooling air) supplied by a supply mechanism (not shown) can be circulated in the internal space 38. Thereby, the temperature of the assembled battery 10 can be adjusted.

  In the battery outer package 1, the plurality of cylindrical portions 35 are arranged side by side in the width direction (X direction) of the conductor sheet 3. The cylindrical portions 37 are also arranged side by side in the width direction (X direction) of the conductor sheet 3. The battery outer package 1 is a honeycomb structure in which a plurality of cylindrical portions 35 are regularly arranged.

The pair of opposing conductor sheets 3, 3 of the battery exterior body 1 has two or more cylindrical portions 35. For example, in the battery outer package 1 shown in FIG. 1, the conductor sheets 31 and 32 have two or more cylindrical portions 35 arranged in the width direction (X direction). The number of cylindrical portions formed by the pair of opposing conductor sheets is preferably 3 or more, and can be, for example, 4-10.
Since the battery outer package 1 has two or more cylindrical portions 35, the assembled battery 10 having two or more unit cells 2 connected in parallel is obtained. The number of the unit cells 2 is preferably 3 or more, for example, 4 to 10.
Since the battery exterior body 1 can constitute the assembled battery 10 in which two or more single cells 2 are arranged in parallel, it is preferable from the viewpoint of power supply.

The battery outer package 1 preferably has two or more pairs of conductive sheets 3 and 3 facing each other. For example, the battery outer package 1 shown in FIG. 1 has two sets of conductor sheets 3 (first set 30A and second set 30B). The number of conductor sheets 3 and 3 facing each other (the number of sets) is preferably 3 or more, for example, 4 to 20 sets.
When the battery outer package 1 has two or more sets of conductor sheets 3 and 3, an assembled battery 10 in which two or more unit cells 2 are arranged in series is obtained. The number of serially connected single cells 2 is preferably 3 or more, for example, 4 to 20.
The battery outer package 1 having two or more sets of conductor sheets 3 and 3 is preferable from the viewpoint of power supply because it can constitute the assembled battery 10 in which two or more unit cells 2 are arranged in series.

  At least one of the plurality of bonding portions 32 </ b> A of the second conductor sheet 32 is electrically connected to at least one of the bonding portions 33 </ b> A of the third conductor sheet 33 via the connection portion 39.

As shown in FIG. 1, the unit cell 2 is, for example, a lithium ion battery, and includes a positive electrode current collector 51, a positive electrode active material layer 52 in contact with the positive electrode current collector 51, a negative electrode current collector 53, and a negative electrode current collector. A negative electrode active material layer 54 in contact with the body 53, a separator 55, and an electrolyte 56 are provided.
The positive electrode current collector 51 and the negative electrode current collector 53 are made of metal, for example. The positive electrode active material layer 52 includes a positive electrode active material such as a lithium-based material. The negative electrode active material layer 55 includes a negative electrode active material such as a carbon-based material. The separator 56 separates the positive electrode active material layer 52 and the negative electrode active material layer 54.

The positive electrode current collector 51 is brought into contact with the metal layer 6 of one of the conductor sheets 3 and 3 (conductor sheets 31 and 33 in FIG. 1) of the cylindrical portion 35 so as to be conductive. 6 is electrically connected.
The negative electrode current collector 53 is in contact with the metal layer 6 of the other one (conductor sheets 32 and 34 in FIG. 1) of the conductor sheets 3 and 3 constituting the cylindrical portion 35 so as to be conductive. 6 is electrically connected.

  The electrolyte 56 (electrolytic solution) is filled in the battery housing part 5. As the electrolyte 56, for example, propylene carbonate (PC), diethyl carbonate (DEC), ethylene carbonate (EC), or the like can be used. The electrolyte 56 (electrolytic solution) is interposed between the positive electrode current collector 51 and the negative electrode current collector 53.

The unit cells 2 are respectively provided in the battery housing portions 5 of the plurality of cylindrical portions 35. The unit cell 2 is preferably flat and has a constant thickness.
The one and the other conductor sheets 3 constituting the cylindrical portion 35 are connected to the positive electrode current collector 51 and the negative electrode current collector 53, respectively, and thus function as connection terminals.

FIG. 3 is a circuit diagram of the assembled battery 10.
As shown in FIG. 3, the plurality of single cells 2 </ b> A and 2 </ b> A are connected in parallel by conductor sheets 31 and 32. The plurality of single cells 2B, 2B are connected in parallel by conductor sheets 33, 34.
The unit cells 2A, 2A and the unit cells 2B, 2B are connected in series by a connection part 39.

[Battery] (Second Embodiment)
FIG. 4 is a cross-sectional view schematically showing an assembled battery 20 that is the assembled battery of the second embodiment. FIG. 5 is an exploded perspective view schematically showing the structure of the assembled battery 20.
As shown in FIGS. 4 and 5, the assembled battery 20 includes a battery outer package 1, a plurality of single cells 2 (see FIG. 1) provided in the battery housing 5, and a pair of sealing plates 11 and 11. Have The assembled battery 20 has a configuration in which sealing plates 11 are added to the assembled battery 10 shown in FIG.
For the sealing plates 11, 11, it is preferable to use a metal plate or foil in order to prevent moisture from entering the battery outer package 1 from the outside. The sealing plates 11 and 11 are respectively provided on one and the other side of the battery exterior body 1 in the Y direction, and close one and the other openings of the cylindrical portion 35.
The sealing plates 11 and 11 are preferably bonded to the battery outer package 1 with an adhesive. Thereby, the opening of the cylindrical portion 35 can be reliably sealed.

The sealing plates 11 and 11 are fixed to the battery exterior body 1 by a fastening fixture 61. The fastening fixture 61 includes, for example, a bolt 62 and a nut 63. The screw shaft portion 62 b of the bolt 62 can be inserted into the insertion hole 11 a from the outer surface of one sealing plate 11 and fastened to the nut 63 on the outer surface side of the other sealing plate 11. Accordingly, the sealing plates 11 and 11 can be pressed toward each other by the head portion 62 a of the bolt 62 and the nut 63, and the sealing plates 11 and 11 can be fixed while pressed against the battery exterior body 1.
The bolt 62 can be inserted into the internal space 38 of the cylindrical portion 37.
Since the fastening fixture 61 can arbitrarily determine the distance between the head portion 62a and the nut 63, the pressing force against the sealing plates 11 and 11 can be adjusted.
The sealing plates 11, 11 are in liquid-tight contact with one and the other end 35 a of the cylindrical portion 35, and can seal the battery housing portion 5.

FIG. 6 is a side view showing a modified example of the assembled battery 20. As shown in FIG. 6, a seal layer 12 (seal member) can be formed on the inner surface 11 c (surface on the battery outer package 1 side) of the sealing plates 11 and 11.
The seal layer 12 is a layer made of an elastic material such as an elastic adhesive (silicone resin or the like), for example. The seal layer 12 preferably has an insulating property.
In the assembled battery 20, the opening of the cylindrical portion 35 can be reliably sealed by bringing the sealing plate 11 into contact with the battery exterior body 1 through the seal layer 12.

[Method of manufacturing assembled battery]
Next, an example of a method for manufacturing the assembled battery 20 will be described.
(First step: Adhesion step)
As shown in FIG. 7A, a long conductor sheet 70 is prepared.
As shown in FIG. 7B, the adhesive 4A is applied to the conductor sheet 70 in a linear form.
As shown in FIG. 7C, a plurality of conductor sheets 70 are stacked and bonded with an adhesive 4A.

(Second step: cutting step)
As shown in FIG. 7C, the plurality of conductor sheets 70 are cut using a cutter 71 so as to have a predetermined Y-direction dimension. As a result, the battery outer package 72 made of the plurality of conductor sheets 3 bonded by the adhesive layer made of the adhesive 4A is obtained.

(Third step: Deployment step)
As shown in FIG. 7D, the plurality of conductor sheets 3 of the battery outer body 72 are spread to form the battery housing portion 5 (see FIG. 2).

(Fourth process: Battery housing process)
As shown in FIG. 8A, the battery main body 2 </ b> C is accommodated in the battery accommodating portion 5 of the battery exterior body 1. The battery body 2C includes a positive electrode current collector 51, a positive electrode active material layer 52, a negative electrode current collector 53, a negative electrode active material layer 54, a separator 55, and the like that constitute the unit cell 2.
The thickness of the battery housing part 5 is adjusted by applying a tensile force in the width direction (X direction) to the battery exterior body 1 or by applying a compressing force in the thickness direction (Z direction). As shown in (B), the conductor sheet 3 is brought into contact with the battery body 2C.
By further applying a tensile force in the width direction (X direction) or a compressive force in the thickness direction (Z direction) to the battery exterior body 1, the distance in the thickness direction of the conductor sheets 3 and 3 can be reduced. Can be small. Thereby, the power generation efficiency of each single cell 2 is improved, and the assembled battery 20 excellent in output characteristics is obtained.

(5th step: sealing plate installation step)
As shown in FIGS. 4 and 5, the battery outer package 1 in which the battery main body 2 </ b> C is accommodated in the battery accommodating portion 5 is disposed between the sealing plates 11 and 11. At this time, the sealing plates 11 and 11 are brought into contact with the battery exterior body 1 by pressing the sealing plates 11 and 11 against the battery exterior body 1 by the fastening fixture 61.
The electrolyte 56 (electrolytic solution) is filled into the cylindrical portion 35 through the filling hole 11 b formed in one sealing plate 11. Next, the filling hole 11b is sealed using a sealing material such as a laminated film including a metal layer. Thereby, the battery accommodating part 5 is sealed.
As a result, the assembled battery 20 shown in FIG. 4 is obtained.

In the assembled battery 10 shown in FIG. 1, since a plurality of battery accommodating portions 5 are formed by a common conductor sheet 3, for example, compared to a battery using a plurality of outer packaging containers that individually wrap a single cell, for example, Since a part of the connection structure and the like can be omitted, the structure can be simplified. Therefore, the battery pack 10 can be reduced in size and weight.
Moreover, since the positive electrode current collector 51 and the negative electrode current collector 53 of the single battery 2 are connected to the conductor sheets 3 and 3, the conductor sheets 3 and 3 can function as terminals. Therefore, the structure of the unit cell 2 can be simplified, and the assembled battery 10 can be further reduced in size and weight.

The assembled battery 10 has a plurality of battery housing portions 5 formed of a common conductor sheet 3, so that it has higher mechanical strength than a battery using a plurality of outer packaging containers that individually wrap single cells. Are better. Damage is unlikely to occur when a tensile force in the width direction (X direction), a shearing force in the length direction (Y direction), or a shearing force in the thickness direction (Z direction) of the conductor sheet 3 is applied. Moreover, since the battery exterior body 1 has the some cylindrical part 35 formed in a row by the common conductor sheet 3, it can improve the durability with respect to the compressive force in the bonded part length direction (Y direction).
Therefore, the assembled battery 10 can be reduced in size and weight, and can have sufficient durability.
Since the assembled battery 10 is small and light, it can be applied to applications where installation space is limited and applications where weight is likely to be a problem. For example, it can be suitably used as a battery for in-vehicle use or residential use.

  Since the assembled battery 10 has a simple structure, it can be configured in a plurality of stages (a structure having a plurality of sets of conductor sheets 3) without complicating the structure. Therefore, the assembled battery 10 in which the plurality of single cells 2 are connected not only in parallel but also in series can be configured. Therefore, it is possible to provide a variety of assembled batteries 10 in which battery capacity, voltage, etc. are matched to the intended use.

The assembled battery 10 has a bent shape in which the intermediate portions 31E, 32E, 33E, and 34E of the conductor sheets 31, 32, 33, and 34 are outwardly convex, and thus one of the opposing conductor sheets is flat. Compared to the battery (see FIG. 14), the difference in the width dimension of the intermediate portion of the facing conductor sheet is reduced. Therefore, the dimension in the thickness direction (Z direction) can be easily adjusted. Therefore, the distance between the electrode plates in the unit cell 2 can be reduced by applying a compressive force in the thickness direction to the conductor sheet 3 and displacing the conductor sheet 3 in a direction approaching each other. Therefore, energy efficiency can be improved and the performance of the assembled battery 10 as a battery can be improved.
Moreover, by applying a force that compresses the battery outer body 1 in the thickness direction, the conductor sheet 3 can be reliably brought into contact with the unit cell 2 to ensure sufficient conduction.
In order to apply a compressive force to the battery pack 10, a structure in which a pressing material (not shown) having elasticity is provided on at least one of the battery exterior bodies 1 in the thickness direction (Z direction) is possible.

  Since the assembled battery 10 can reduce the difference in the width dimension of the intermediate part of the conductive sheets facing each other, as shown in FIGS. 7A to 7D, a plurality of flat conductive sheets 70 that are superimposed are provided. Easy to use.

  In the assembled battery 10, since the cylindrical portion 35 has a hexagonal cylindrical shape, the tensile force in the width direction (X direction) of the conductor sheet 3, the shearing force in the bonded portion length direction (Y direction), or the thickness direction The strength against the shearing force in the (Z direction) can be increased. Further, since the cylindrical portion 35 is a hexagonal cylindrical shape, a sufficient volume can be secured in the cylindrical portion 35.

In the assembled battery 10, since the internal space 38 is secured between the second conductor sheet 32 and the third conductor sheet 33, a heat medium (cooling water, cooling air, etc.) is supplied to the internal space 38. By circulating, the temperature of the assembled battery 10 can be adjusted.
Since the internal space 38 is adjacent to the battery housing part 5, the temperature of the unit cell 2 in the battery housing part 5 can be adjusted efficiently.

  In the assembled battery 10, the adhesive portions 32 </ b> A and 33 </ b> A and the adhesive portions 32 </ b> B and 33 </ b> B are alternately arranged in the width direction (X direction) on the conductor sheets 32 and 33, so The honeycomb structure is arranged side by side in the (X direction). Therefore, as described above, the battery pack 10 can be reduced in size and weight.

  The assembled battery 10 has a width sufficient for the battery accommodating portion 5 that is the internal space of the cylindrical portion 35 because the adhesive portions 32B and 33B of the conductor sheets 32 and 33 are wider than the adhesive portions 32A and 33A. Can be secured. Therefore, the unit cells 2 can be arranged densely, and the battery pack 10 can be downsized.

  In the assembled battery 10, since the conductor sheet 3 has flexibility, the cylindrical part 35 is easily displaced so as to approach each other in the thickness direction (Z direction). Therefore, as described above, the performance of the assembled battery 10 as a battery can be enhanced.

  Next, a modified example of the battery outer package 1 will be described. Hereinafter, the same components as those of the battery outer package 1 shown in FIGS. 1 and 2 may be denoted by the same reference numerals and description thereof may be omitted.

FIG. 9 is a cross-sectional view schematically showing an assembled battery 10 </ b> A using a battery outer package 1 </ b> A that is a first modification of the battery outer package 1.
The battery outer package 1A has the same structure as the battery outer package 1 shown in FIGS. 1 and 2 except that the conductor sheets 33 and 34 are not provided and only the pair of conductor sheets 3 (31, 32) is used. is there.

FIG. 10 is a cross-sectional view schematically showing an assembled battery 10 </ b> B using a battery exterior body 1 </ b> B that is a third modification of the battery exterior body 1.
The battery outer package 1B has the same structure as the battery outer package 1A shown in FIG. 9 except that a plurality of conductor sheets 81 arranged in the width direction (X direction) are used instead of the first conductor sheet 31. is there.
The conductor sheet 81 is, for example, a strip having a constant width along the Y direction.
The conductor sheet 81 is bonded to the bonding portion 32A of the second conductor sheet 32 by the adhesive layer 41 in the bonding portion 81A that is a portion including both side edge portions.
The portion (intermediate portion 81E) between the adhesive portions 81A and 81A of the first conductor sheet 81 and the intermediate portion 32E of the second conductor sheet 32 form a tubular portion 85.

FIG. 11 is a cross-sectional view showing a cylindrical portion 95 that is a first modification of the cylindrical portion 35. The intermediate portion 91E1 of the first conductor sheet 31 includes a substrate portion 31C and a pair of side plate portions 91D1 and 91D1.
The side plate portions 91D1 and 91D1 have a curved shape (for example, a circular arc shape) that protrudes outward from the cylindrical portion 95, and gradually approaches the second conductor sheet 32 in the widening direction from both side edges of the substrate portion 31C. Inclined and extended. The intermediate portion 91E1 has a bent shape that is convex in the direction away from the second conductor sheet 32 (outward).

The intermediate part 92E1 of the second conductor sheet 32 has a substrate part 32C and a pair of side plate parts 92D1, 92D1. The side plate portions 92D1 and 92D1 have a curved shape (for example, a circular arc shape) that protrudes outward from the cylindrical portion 95, and gradually approaches the first conductor sheet 31 in the widening direction from both side edges of the substrate portion 32C. Inclined and extended. The intermediate portion 92E1 has a bent shape that is convex in the direction away from the first conductor sheet 31 (outward).
The intermediate portions 91E1 and 92E1 of the conductor sheets 31 and 32 form a cylindrical portion 95. The cylindrical portion 95 is a preferable configuration when the battery accommodating portion 5 is enlarged and the volume ratio of the battery in the assembled battery is desired to be increased.

FIG. 12 is a cross-sectional view showing a cylindrical portion 105 that is a second modification of the cylindrical portion 35.
The intermediate portion 91E2 of the first conductor sheet 31 includes a substrate portion 31C and a pair of side plate portions 91D2 and 91D2. The side plate portions 91D2 and 91D2 have a curved shape (for example, a circular arc shape) that protrudes inward of the cylindrical portion 105, and gradually approaches the second conductor sheet 32 in the widening direction from both side edges of the substrate portion 31C. Inclined and extended. The intermediate portion 91E2 has a bent shape that is convex in the direction away from the second conductor sheet 32 (outward).

The intermediate portion 92E2 of the second conductor sheet 32 includes a substrate portion 32C and a pair of side plate portions 92D2 and 92D2. The side plate portions 92D2 and 92D2 have a curved shape (for example, a circular arc shape) that protrudes inward of the cylindrical portion 105, and gradually approaches the first conductor sheet 31 in the widening direction from both side edges of the substrate portion 32C. Inclined and extended. The intermediate portion 92E2 has a bent shape that is convex in the direction away from the first conductor sheet 31 (outward).
The intermediate portions 91E2 and 92E2 of the conductor sheets 31 and 32 form a cylindrical portion 105. The cylindrical portion 105 is a preferable configuration when it is desired to increase the internal space 38 (see FIG. 2) and increase the cooling efficiency by a heat medium such as cooling water.

FIG. 13 is a cross-sectional view showing a cylindrical portion 115 that is a third modification of the cylindrical portion 35.
The intermediate portion 91E3 of the first conductor sheet 31 includes a substrate portion 31C and a pair of side plate portions 91D3 and 91D3.
The side plate portion 91D3 includes a first curved portion 91D31 having a curved shape that protrudes outward from the cylindrical portion 115 (for example, a circular arc shape), and a curved shape that protrudes inward from the cylindrical portion 115 (for example, a circular cross-section). An arc shape) is combined with the second curved portion 91D32 to form an S shape. The first bending portion 91D31 is connected to the substrate portion 31C, and the second bending portion 91D32 is connected to the bonding portion 31A. The side plate portions 91D3 and 91D3 are inclined and extended so as to gradually approach the second conductor sheet 32 in the widening direction from both side edges of the substrate portion 31C.

The intermediate portion 92E3 of the second conductor sheet 32 includes a substrate portion 32C and a pair of side plate portions 92D3 and 92D3.
The side plate portion 92D3 includes a first curved portion 92D31 having a curved shape that protrudes outward from the cylindrical portion 115 (for example, an arc shape in cross section) and a curved shape that protrudes inward from the cylindrical portion 115 (for example, a circular shape in cross section). The second curved portion 92D32 having an arc shape is combined with an S shape. The first bending portion 92D31 is connected to the substrate portion 32C, and the second bending portion 92D32 is connected to the bonding portion 32A. The side plate portions 92D3 and 92D3 are inclined and extended so as to gradually approach the first conductor sheet 31 in the widening direction from both side edges of the substrate portion 32C.
The intermediate portions 91E3 and 92E3 of the conductor sheets 31 and 32 form a cylindrical portion 115. Since the cylindrical part 115 can be produced even if the tensile force applied to the conductor sheet 3 is small in the unfolding process shown in FIG.

For comparison, an assembled battery using a battery casing having a shape different from that of the battery casing 1 of the embodiment will be described.
FIG. 14 is a cross-sectional view schematically showing an assembled battery 110 using a battery outer package 101 different from the battery outer package 1 of the embodiment shown in FIG.
The battery exterior body 101 includes first to fourth conductor sheets 131, 132, 133, and 134.
The intermediate portion 131E of the first conductor sheet 131 includes a substrate portion 131C and a pair of side plate portions 131D and 131D that are inclined with respect to the substrate portion 131C. The intermediate portion 133E of the third conductor sheet 133 has a substrate portion 133C and a pair of side plate portions 133D and 133D that are inclined with respect to the substrate portion 133C.
The second conductor sheet 132 and the fourth conductor sheet 134 are formed flat. Therefore, the cylindrical part 135 (135A) formed by the intermediate part 131E of the first conductor sheet 131 and the second conductor sheet 32, and the intermediate part 133E of the third conductor sheet 133 and the fourth conductor sheet The cylindrical portion 135 (135B) formed by the shape 134 is a square cylinder having a trapezoidal cross section.

  Compared to the battery exterior body 1 (see FIG. 1) having the hexagonal tubular portion 35, the battery exterior body 101 is flat in the conductor sheets 132 and 134. Therefore, the tubular portion 135 is deformed in the widening direction. It is difficult to adjust the distance between the electrode plates. Therefore, it is disadvantageous in terms of energy efficiency. Moreover, the battery exterior body 101 tends to cause wrinkles in the conductor sheets 131, 132, 133, and 134 during manufacturing. In addition, when the battery exterior body 101 is applied with a compressive force in the thickness direction (Z direction) (see FIG. 6), the conductor sheets 131, 132, 133, and 134 are likely to be distorted.

In addition, this invention is not limited to the above-mentioned embodiment, A various change is possible in the range which does not deviate from the summary of this invention.
In the battery outer package 1 shown in FIG. 1, the conductor sheets 31 and 32 are both formed continuously in the width direction across the plurality of cylindrical portions 35, but only one of the facing conductor sheets is formed. The structure currently formed continuously in the width direction over the some cylindrical part is also possible.
In the battery outer package 1 shown in FIG. 1, the adhesive layer 42 that bonds the second conductor sheet 32 and the third conductor sheet 33 may not have an integral structure, for example, two spaced apart in the width direction. You may be comprised from the above adhesion part. Similarly, the adhesive layers 41 and 43 may be composed of, for example, two or more adhesive portions that are separated in the width direction.
As the conductor sheet, a sheet having no flexibility may be used.
In the battery exterior body 1 shown in FIG. 1, the intermediate portions 31E, 32E, 33E, and 34E have a bent shape that is convex outward, but at least a portion of the intermediate portion is outwardly convex. Any bent shape may be used.

In the battery outer package 1, the side plate portions 31D, 32D, 33D, and 34D of the conductor sheets 31, 32, 33, and 34 are inclined at an angle of less than 90 ° with respect to the substrate portions 31C, 32C, 33C, and 34C. The cylindrical portion 35 has a hexagonal cylindrical shape, but the angle may be 90 ° or more.
The battery accommodated in the battery outer package 1 is not limited to a lithium ion battery, and may be an electric double layer capacitor or the like.
In the battery pack 10 shown in FIG. 1, the positive electrode current collector 51 and the negative electrode current collector 53 of the unit cell 2 are electrically connected by directly contacting the conductor sheet 3 of the battery outer package 1. The positive electrode current collector 51 and the negative electrode current collector 53 may be electrically connected by indirectly contacting the conductor sheet 3 via a conductor (not shown).

As a structure for sealing the opening of the cylindrical portion 35, a lid body that is a two-layered body composed of a continuous foamed resin sheet and an independent foamed resin sheet may be used. For example, the opening of the cylindrical portion 35 is sealed by pressure-inserting the lid body in which the continuous foamed resin sheet is impregnated with an electrolytic solution-resistant adhesive (for example, a polyolefin-based adhesive). can do.
In order to provide waterproofness to the assembled battery, a barrier material such as a metal foil can be provided on the surface layer of the lid. The barrier material is provided so as not to cause a short circuit in the assembled battery. In addition, the structure which seals opening of a cylindrical part is not limited to this.

DESCRIPTION OF SYMBOLS 1,1A, 1B ... Battery exterior body, 2 ... Single cell, 3,31,32,33,34 ... Conductor sheet, 4,41,42,43,41A, 41B, 43A, 43B ... Adhesive layer, 5 , 5A, 5B ... battery housing part, 6 ... metal layer, 7 ... resin layer, 10, 20 ... assembled battery, 11 ... sealing plate, 12 ... seal layer (sealing member), 30A ... first set, 30B ... first 2 sets, 31A, 32A, 32B, 33A, 33B, 34A ... Adhesive part, 31C, 32C, 33C, 34C ... Substrate part, 31D, 32D, 33D, 34D, 91D1, 91D2, 91D3, 92D1, 92D2, 92D3 ... Side plate Part, 31E, 32E, 33E, 34E, 81E, 91E1, 91E2, 91E3, 92E1, 92E2, 92E3... Intermediate part, 32a... Upper surface (one surface), 33a ... lower surface (one surface) of the third conductor sheet, 33b ... upper surface (other surface) of the third conductor sheet, 35, 35A, 35B, 85, 95, 105, 115 ... Cylindrical part, 38 ... Internal space (space between one set of opposing conductor sheets and the other set of opposing conductor sheets), 51 ... positive electrode current collector, 52 ... positive electrode active material layer, 53 ... Negative electrode current collector, 54 ... Negative electrode active material layer, 55 ... Separator, 56 ... Electrolyte, 61 ... Fastening fixture

Claims (12)

A plurality of unit cells, and a battery outer body that covers the unit cells,
The battery exterior body includes a plurality of conductor sheets,
At least a pair of the conductive sheets facing each other among the conductive sheets are partially bonded at a plurality of linear bonding portions,
The plurality of adhesive portions are formed apart from each other in the width direction orthogonal to the length direction,
The pair of opposing conductor sheets form a plurality of cylindrical parts partitioned by the adhesive part, and a battery accommodating part is secured inside the cylindrical part,
At least one of the pair of conductor sheets is continuously formed in the width direction over the plurality of cylindrical portions,
The cylindrical part is formed by an intermediate part between the adhering parts adjacent to the conductor sheet,
The middle part of the pair of conductor sheets has a bent shape in which at least a part is convex outward,
The unit cell includes a positive electrode current collector, a positive electrode active material layer in contact with the positive electrode current collector, a negative electrode current collector, a negative electrode active material layer in contact with the negative electrode current collector, the positive electrode active material layer, and the A separator that separates the negative electrode active material layer, and an electrolyte, each provided in the plurality of battery housing portions,
The assembled battery, wherein the positive electrode current collector is in conductive contact with one of the pair of conductor sheets, and the negative electrode current collector is in contact with the other of the pair of conductive sheets. The intermediate portions of the pair of conductor sheets extend at an incline with respect to the substrate portion so as to approach the opposite conductor sheet toward the widening direction from both side edges of the substrate portion and the substrate portion, respectively. A pair of side plate portions to be taken out,
The assembled battery according to claim 1, wherein the cylindrical portion is formed in a hexagonal cylindrical shape by the substrate portion and the side plate portion of the pair of conductor sheets. Having a plurality of sets of the pair of conductor sheets,
The conductive sheet having both surfaces bonded to the other conductive sheet has one surface bonded to the other conductive sheet and the other surface bonded to the other conductive sheet. The assembled battery according to claim 1, wherein the bonded portions are arranged alternately in the width direction.   Of the bonded portion in which the one surface is bonded to the other conductive sheet and the bonded portion in which the other surface is bonded to the other conductive sheet, one is formed wider than the other. The assembled battery according to claim 3.   A space is secured between one set of the facing conductive sheets and the other set of the facing conductive sheets among the plurality of sets of facing conductive sheets adjacent in the thickness direction. Item 5. The assembled battery according to Item 3 or 4.   The sealing body which is equipped with the sealing plate which closes one side and the other opening of the said cylindrical part at the both ends of the said adhesion part length direction of the said battery exterior body respectively is provided. The assembled battery as described.   The assembled battery according to claim 6, wherein the sealing plate is in contact with an opening of the cylindrical portion via a seal member.   The said sealing plate which closes one opening of the said cylindrical part, and the said sealing plate which closes the other opening are being fixed with respect to the said battery exterior body with the fastening fixture. 7. The assembled battery according to 7. The conductor sheet has a metal layer,
The assembled battery according to claim 1, wherein the metal layer faces the battery housing portion.   The assembled battery according to claim 9, wherein the metal layer is a metal foil containing one or more of aluminum, copper, stainless steel, nickel, and iron. The conductor sheet is a laminate further having a resin layer,
The assembled battery according to claim 9 or 10, wherein the resin layer includes one or more of polyester, polyamide, polyimide, polyolefin, acrylic resin, polyurethane, fluororesin, and thermosetting resin.   The assembled battery according to any one of claims 1 to 11, wherein the conductor sheet is bonded to the adhesive portion with a polyolefin-based adhesive.

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