JP2000251870A - Layered type polymer electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently manufacture layered electrodes by contriving shapes for current collecting members of electrodes which constitute the lower and upper outermost layers of a layered electrode group. SOLUTION: This battery is a layered type polymer electrolyte battery, wherein a layered electrode group, in which positive electrodes 6 with a positive electrode mixture layer formed on a current collecting member and negative electrodes 7 with a negative electrode mixture layer formed on a current collecting member are layered via polymer electrolyte layers therebetween, is sheathed by a facing member. The lower and upper outermost layers constituting the layered electrode group are made to have the same polarity, and electrode leads 8, 9 are formed in a central part in the electrode-width direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stacked polymer electrolyte battery, and more particularly, to a stacked polymer electrolyte battery suitable for use as a power source for portable electronic devices, electric vehicles, road leveling, and the like.

[0002]

2. Description of the Related Art In a polymer electrolyte battery, the electrolyte can be made into a sheet shape, thereby making it possible to produce a large-area and thin battery such as an A4 size plate or a B5 size plate.
Application to various thin products has become possible, and the range of use of batteries has been greatly expanded. Batteries using this polymer electrolyte have excellent safety and storage properties including leakage resistance,
Moreover, because it is thin and flexible, it has the unique feature of batteries that can be designed to match the shape of the device.

[0003] This polymer electrolyte battery usually uses a laminate film in which an aluminum film is used as a core material, and a resin film as an adhesive layer is disposed on a surface on the inner side when used as an exterior body, as a sheet. By packaging the unit cell having the above electrode and a sheet-like polymer electrolyte layer laminated with the above-mentioned package, a thin sheet-type battery is completed.

As shown in FIG. 1 (which schematically shows a cross-sectional structure of a stacked electrode group), a sheet-like electrode constituting this type of stacked battery is intended to improve the capacity density. , An active material layer was formed on both sides of the current collector by applying,
So-called double-sided coated electrodes are often used. That is, one current collector serves to transfer electrons to and from the active material layers on both surfaces (two surfaces). In order to allow the battery reaction to proceed in such an electrode configuration, it is, of course, necessary to provide electrodes 3 having other polarities on both surfaces of the central electrode 1 via the polymer electrolyte layer 2.

However, as in the case of the electrode 1, if the electrode 3 has an electrode structure in which active material layers are formed on both surfaces of the current collector, the electrodes 3 correspond to the upper and lower outermost layers constituting the stacked electrode group.
The active material layer portion of the electrode 3 that is not opposed to the above does not contribute to the battery reaction, and there is a problem that the electrode configuration in which the active material is provided on both surfaces to improve the capacity density is not utilized.

In order to solve such a problem, as shown in FIG. 2 (which schematically shows a cross-sectional structure of the stacked electrode group), electrodes 3 corresponding to upper and lower outermost layers constituting the stacked electrode group are used. Is a so-called single-sided coated electrode provided with an active material layer only on one side of the current collector, and the active material layer 3 is configured to face the electrode 1 with the polymer electrolyte layer 2 interposed therebetween.
It is possible to solve the problem of the decrease in the capacitance density described above.

[0007] However, in the conventional laminated battery, FIG.
As shown in FIG. 1 (a plan view schematically showing a state in which the electrode 1 and the electrode 3 are overlapped), an active material is provided on the current collector on the electrode 1 in order to take out the current generated by the battery reaction to the outside. A lead portion 4 on which no active material layer is formed on the current collector is also formed on the electrode 3 similarly to the lead portion 4 on which no layer is formed. 1,3
Is formed by punching with a punching die, but the shape is substantially similar.

[0008]

In order to improve the capacity density of a stacked battery, as described above, it is necessary to employ single-side coated electrodes as the upper and lower outermost electrodes of the stacked electrode group. However, in producing the stacked electrode group, only the two single-sided coated electrodes constituting the outermost layer have the active material layer forming surface facing inward to contribute to the battery reaction, in other words, the position of the lead portion 5 of the electrode 3. Must be transported to the stacked electrode group manufacturing process in a uniform direction, which not only complicates the work, but also incorrectly replaces the electrode with the active material layer formed on the non-regular surface by mistake. The problem of supply to the factory also raises the problem.

The present invention solves the above-mentioned problems, and a stacked battery can be efficiently manufactured by devising the shape of the current collector of the electrodes constituting the upper and lower outermost layers of the stacked electrode group. The purpose is to be.

[0010]

Means for Solving the Problems The present invention comprises a positive electrode having a positive electrode mixture layer formed on a current collector and a negative electrode having a negative electrode mixture layer formed on the current collector. A laminated polymer electrolyte battery in which a laminated electrode group laminated with a polymer electrolyte layer interposed therebetween is packaged with a package, wherein the upper and lower outermost electrodes constituting the laminated electrode group have the same polarity, and It is an object of the present invention to provide a laminated polymer electrolyte battery characterized in that the lead portion is formed at the center in the electrode width direction.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, an aluminum foil, a punched metal, a net, an expanded metal, or the like can be used as a current collector for a positive electrode, and an aluminum foil is usually used. The current collector of the positive electrode preferably has a thickness of 30 μm or less from the viewpoint of reducing the overall thickness of the positive electrode. Because I do n’t go out more,
Less risk of damage.

However, if the thickness is too small, wrinkles may occur when the positive electrode mixture-containing paste is applied, or the film may be broken by pulling in the preparation of the positive electrode. Below, 10 μm or more is preferable.

Usually, the lead portion on the positive electrode side is formed by leaving an exposed portion of the current collector without forming a positive electrode mixture layer on a part of the current collector made of aluminum at the time of manufacturing the positive electrode, and using that as the lead portion. Provided by However, the lead portion is not necessarily required to be integrated with the current collector from the beginning,
The current collector may be provided by connecting an aluminum foil or the like later.

In the present invention, as the current collector of the negative electrode, copper foil, punched metal, mesh, expanded metal, and the like can be used. Usually, a copper foil is used. Due to thickness reduction, thickness is 3
The thickness is preferably 0 μm or less, and in the present invention, even with such a thin thickness, the exposed portion does not come out of the sealing portion of the exterior body, so that there is little possibility of breakage.

However, if it is too thin, wrinkles may occur when the negative electrode mixture-containing paste is applied, or the film may be broken by pulling, so that the thickness is 30 μm as described above. Below, 5 μm or more is preferable.

Also, the lead portion on the negative electrode side is usually left as a lead portion while leaving the exposed portion of the current collector without forming the negative electrode mixture layer on a part of the copper current collector at the time of producing the negative electrode. It is provided by. However, the lead portion on the negative electrode side is not necessarily required to be integrated with the current collector from the beginning, and may be provided by connecting a copper foil or the like to the current collector later.

In the present invention, it is preferable that at least one of the positive electrode and the negative electrode is surrounded by a polymer electrolyte layer so that the electrode and the polymer electrolyte layer are integrated. As an embodiment in this case, after surrounding the electrodes in a bag-like porous sheet serving as a support for the polymer electrolyte layer,
In the case where an electrolyte solution containing a gelling component which is a precursor of a polymer electrolyte is entirely retained and gelled, and an integrated product of an electrode containing a polymer electrolyte and a polymer electrolyte layer is produced, or a polymer electrolyte is contained. A case in which the electrode and the polymer electrolyte layer are integrated by sandwiching the electrode between strip-shaped polymer electrolyte sheets in which a porous sheet support is provided. Further, when the electrode is surrounded by an electrolyte layer by sandwiching the latter electrode between strip-shaped polymer electrolyte sheets, one strip-shaped polymer electrolyte sheet is folded at almost the center thereof to form an electrode between the polymer electrolyte sheets. May be surrounded by the polymer electrolyte layer, or the electrode may be surrounded by the polymer electrolyte layer by sandwiching the electrode between two strip-shaped polymer electrolyte sheets.

In the present invention, as the porous sheet serving as a support for the polymer electrolyte, for example, a nonwoven fabric or a microporous film is used. Examples of the nonwoven fabric include nonwoven fabrics such as polypropylene, polyethylene, polyethylene terephthalate, and polybutylene terephthalate. Examples of the microporous film include microporous films of polypropylene, polyethylene, and ethylene-propylene copolymer.

Since the nonwoven fabric has a high porosity and can easily hold an electrolytic solution containing a gelling component, the case of using the nonwoven fabric as a support in the present invention will be described in detail. To describe this nonwoven fabric in more detail, for example, a very thin nonwoven fabric having a basis weight of 12 g / m ² and a thickness of 30 μm can be used.

Since such a nonwoven fabric is thin, it has low mechanical strength including tensile strength, and is difficult to handle alone. For example, the nonwoven fabric is formed into a bag, and the electrodes are accommodated in the bag-shaped nonwoven fabric. By surrounding and unifying the nonwoven fabric and the electrode, the strength of the electrode can compensate for the insufficient strength of the nonwoven fabric. Also, without forming a bag shape, the strip-shaped non-woven fabric is folded almost at the center, and the electrode is sandwiched between the non-woven fabrics to surround the electrode with the non-woven fabric and integrate the electrode and the non-woven fabric. By laminating strip-shaped non-woven fabrics, sealing one end of the non-woven fabric, sandwiching the electrodes between the non-woven fabrics, surrounding the electrodes with a support, and integrating the electrodes and the non-woven fabrics, the strength of the It is suitable for use because it can compensate for insufficient strength, improve workability during battery assembly, reduce internal resistance, and improve load characteristics. The case where a microporous film is used as the support is the same as the case of the nonwoven fabric.

As described above, the electrode and the support are integrated by surrounding the electrode with a support made of a porous sheet such as a non-woven fabric, and gelling is performed by holding an electrolyte containing a gelling component. Thereby, the adhesion between the electrodes and the polymer electrolyte layer is better than when the electrodes and the polymer electrolyte sheet are individually gelled to form the electrode and the polymer electrolyte sheet and then laminated, and bubbles, foreign substances, and the like can be interposed between the layers. Since there is no,
Ion transfer at the interface becomes smooth, and reactivity between the positive and negative electrodes improves. In addition, by surrounding either one of the positive electrode and the negative electrode with a support, it can also serve as a physical separator.

In the present invention, either the positive electrode or the negative electrode may be surrounded by the electrolyte layer to integrate the electrode and the electrolyte layer. At this time, the positive electrode is surrounded by the electrolyte layer and When the battery and the electrolyte layer are integrated, the battery capacity can be increased as compared with the case where the negative electrode is surrounded by the electrolyte layer. That is, since it is common practice to make the negative electrode larger than the positive electrode in order to prevent the occurrence of dendrite and ensure safety, if the positive electrode is surrounded by the electrolyte layer, the negative electrode is surrounded by the electrolyte layer rather than the electrolyte layer. Can be reduced, and as a result, the battery capacity can be increased.
Also, in the case where the negative electrode is surrounded by the electrolyte layer and the negative electrode and the electrolyte layer are integrated, the interface state between the negative electrode and the electrolyte layer can be made uniform, so that, similarly to the positive electrode, there is an effect of improving the reactivity. .

Further, if both the positive electrode and the negative electrode are surrounded by the electrolyte layer, the thickness of the electrolyte layer is increased by an amount. However, since both the electrodes are integrated with the electrolyte layer, both the positive electrode and the negative electrode are polarized. Since the reaction can be reduced and the reaction at the time of charging and discharging can smoothly proceed, the load characteristics can be greatly improved.

In the present invention, the term “integration of the electrode and the electrolyte layer” means that the electrode and the electrolyte layer are brought into close contact with each other without bubbles or foreign matter between the electrode and the electrolyte layer. It does not mean that it is inseparably bonded.

When the support made of a porous sheet such as the nonwoven fabric is made into a bag shape, if the bag shape is described as a square shape, for example, one side is usually open and the other three sides are sealed. However, the sealing is not always required to be continuously performed, and the sealing may be discontinuously performed.

When the electrode is accommodated in the bag-like support, it is not required that the support be made into a bag-like shape in advance, and the electrode is made into a strip-like support (for example, the length is equal to the length of the electrode). (A strip-shaped support having a size of twice or more and a width larger than the width of the electrode) is placed on one side from the substantially central portion in the longitudinal direction, and the other side is folded back (that is, the electrode is substantially at the central portion). In a state sandwiched between the folded support), and continuously or discontinuously seal both sides in the width direction,
What is necessary is just to make the electrode accommodated in the bag-shaped support body.

Also, in the case where two supports are overlapped and one end thereof is sealed and an electrode is sandwiched between them, it is not required to seal in advance, and the electrodes are formed in a single strip-like support ( For example, placed on a strip-shaped support whose length is longer than the length of the electrode and whose width is larger than the width of the electrode),
Another strip-shaped support may be placed thereon, and one end of the support may be continuously or discontinuously sealed so that the electrode is sandwiched between the supports.

Examples of the electrolyte for forming the polymer electrolyte layer include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propionate, ethylene carbonate, propylene carbonate, and the like.
Butylene carbonate, gamma-butyrolactone, ethylene glycol sulfite, 1,2-dimethoxyethane, 1,3-dioxolan, tetrahydrofuran, 2-
Organic solvents such as methyl-tetrahydrofuran and diethyl ether include, for example, LiClO ₄ , LiPF ₆ , LiB
F ₄ , LiAsF ₆ , LiSbF ₆ , LiCF ₃ SO ₃ , L
iC ₄ F ₉ SO ₃ , LiCF ₃ CO ₂ , Li ₂ C ₂ F ₄ (S
O ₃ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ ,
LiC _n F _2n + 1SO ₃ (n ≧ 2), LiN (RfOSO ₂ ) ₂
What is prepared by dissolving an inorganic ion salt such as [here, Rf is a fluoroalkyl group] is used. The concentration of the inorganic ion salt in the electrolytic solution is set to 0.1.
It is preferably from 5 to 1.5 mol / l, particularly preferably from 0.9 to 1.25 mol / l.

Similarly, as the gelling component for converting the electrolytic solution into a polymer electrolyte, for example, polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile,
After dissolving a linear polymer such as a vinylidene fluoride-propylene hexafluoride copolymer in an electrolytic solution by heating and then cooling it to polymerize the electrolytic solution, or polymerizing with actinic rays Examples include a crosslinkable composition containing a monomer or prepolymer containing two or more possible double bonds per molecule as a main component.

Examples of the monomer capable of being polymerized by actinic light include monomers having two double bonds per molecule (bifunctional crosslinkable monomers) such as 1,3-butanediol diacrylate and 1,4 -Butanediol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, propylene glycol diacrylate, dipropylene glycol diacrylate Acrylate, tripropylene glycol diacrylate, ethoxylated bisphenol A diacrylate, novolak diacrylate, propoxylated neopentyl glycol diacrylate Such as difunctional acrylates and the acrylate and similar difunctional methacrylates such as chromatography bets and the like.

As a monomer having three double bonds per molecule which can be polymerized by actinic rays (trifunctional crosslinkable monomer), for example, tris (2-hydroxyethyl)
Trifunctional acrylates such as isocyanurate triacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate, and caprolactone-modified trimethylolpropane triacrylate And the same trifunctional methacrylate as the above acrylate.

Examples of monomers having four or more double bonds per molecule which can be polymerized by actinic rays (tetrafunctional or more crosslinkable monomers) include, for example, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, ethoxylated Examples include tetrafunctional or higher acrylates such as pentaerythritol tetraacrylate, dipentaerythritol hydroxypentaacrylate, dipentaerythritol hexaacrylate, and tetrafunctional or higher methacrylates similar to the above acrylates.

Further, two double bonds polymerizable by actinic rays
Examples of the prepolymer having at least 4, preferably at least 4, include prepolymers of urethane acrylate, epoxy acrylate, and polyester acrylate, and can be used in place of the above-mentioned monomers.

In the present invention, the monomer or prepolymer having two or more double bonds polymerizable by actinic light per molecule may be used as a main component, and may be used for adjusting physical properties such as gel hardness. For this purpose, a monofunctional monomer or the like can be used in combination. Further, a usage such as mixing a bifunctional monomer and a hexafunctional monomer is also possible.

In the present invention, the term "crosslinkable composition comprising a monomer or prepolymer having at least two double bonds per molecule capable of being polymerized by actinic light" as a main component refers to the above-mentioned crosslinkable composition polymerized by actinic light. Monomers or prepolymers containing only possible monomers or prepolymers having two or more double bonds per molecule, and monomers or prepolymers having two or more double bonds per molecule that can be polymerized with actinic rays with monofunctional monomers In the case where a monomer or a prepolymer having two or more double bonds per molecule capable of being polymerized by actinic rays is used in combination with a monofunctional monomer or the like as in the latter case, the crosslinkable composition Of a monomer or a prepolymer having two or more double bonds per molecule which can be polymerized by actinic light, more than 50% by weight, especially 70% by weight. Or more at a wavelength of 550 nm. Also,
The crosslinkable composition does not have to be all crosslinkable as long as the constituents thereof are not crosslinkable, as long as it is entirely crosslinkable.
Other components can be added as needed.

And, if necessary, as a polymerization initiator,
For example, benzoins, benzoin alkyl ethers, benzophenones, benzoylphenylphosphine oxides, acetophenones, thioxanthones, anthraquinones, and the like can be used. Further, alkylamines, aminoesters and the like can be used as a sensitizer of the polymerization initiator.

In the present invention, for example, ultraviolet (UV), electron beam (EB), visible light, far ultraviolet and the like can be used as the active light.

[0038]

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited only to those illustrated in the embodiments.

Preparation of positive electrode: LiCo as positive electrode active material
80 parts by weight of O _2, 10 parts by weight of acetylene black as a conductive additive, and polyvinylidene fluoride 1 as a binder
0 parts by weight were uniformly mixed using N-methylpyrrolidone as a solvent to prepare a positive electrode mixture-containing paste.
The paste was applied to both sides of a 20 μm-thick aluminum foil serving as a current collector, dried, and calendered. The thickness of the positive electrode mixture layer was adjusted to a total thickness of 130 μm. The positive electrode was manufactured by cutting so that the application area was 70 mm × 40 mm. However, in producing the positive electrode, the paste containing the positive electrode mixture was not applied to part of the aluminum foil, the exposed portion of the aluminum foil was left as a lead portion, and the lead portion was used as a connection portion with the positive electrode terminal.

Preparation of negative electrode A: graphite 9 as a negative electrode active material
0 parts by weight and 10 parts by weight of polyvinylidene fluoride are mixed uniformly using N-methylpyrrolidone as a solvent to prepare a paste containing the negative electrode mixture, and a thickness of 10
After coating on both sides of a μm current collector and drying, the thickness of the negative electrode mixture layer was adjusted to a total thickness of 130 μm by calendering, and the active material application area was 72 mm × 42 mm.
To obtain a negative electrode A. The cutting was performed so that the lead portion serving as a connection portion with the negative electrode terminal was located at the center position in the width direction of the electrode. Also, similar to the above positive electrode,
In producing the negative electrode A, the paste containing the negative electrode mixture was not applied to the lead portion, and the exposed portion of the copper foil was left as the lead portion.

Preparation of negative electrode B: The same negative electrode mixture-containing paste as described above was applied to one side of a current collector made of copper foil and having a thickness of 10 μm, dried, and then calendered to a total thickness of 70 μm. The thickness of the negative electrode mixture layer was adjusted so as to obtain a negative electrode B. The negative electrode B was prepared by cutting the negative electrode mixture layer so that the active material application area became 72 mm × 42 mm. Similarly to the above-described positive electrode, in producing the negative electrode B, the negative electrode mixture-containing paste was not applied to the lead portion, and the exposed portion of the copper foil was left as the lead portion.

Preparation of gelling component-containing electrolyte: volume ratio of propylene carbonate to ethylene carbonate 1:
2,4,6 as an initiator in an electrolyte prepared by dissolving 1.22 mol / l of LiPF _{6 in} the mixed solvent of
-Trimethylbenzoyldiphenylphosphine oxide (trade name: Lucirin TPO, manufactured by BSF Japan Co., Ltd.) was added to 2% by weight of the monomer component in advance and dissolved, and dipentaerythritol hexaacrylate was used therein. One minute before, the mixture was added to a concentration of 6% by weight and mixed to prepare an electrolytic solution containing a gelling component. Hereinafter, the electrolyte containing the gelling component is simply referred to as a “gelling component-containing electrolyte” as described above.

In this embodiment, the positive electrode is wrapped with a nonwoven fabric serving as a support for the polymer electrolyte layer. The positive electrode and the support are integrated, and the gelling component-containing electrolyte is retained throughout the
It was gelled to obtain a polymer electrolyte-containing positive electrode unit.
The negative electrode held the gelled component-containing electrolyte solution without being wrapped in a nonwoven fabric and gelled to obtain a polymer electrolyte-containing negative electrode.

Preparation of polymer electrolyte-containing positive electrode unit: As a support, a polybutylene terephthalate nonwoven fabric having a thickness of 30 μm and a basis weight of 12 g / m ² [manufactured by NKK, MB
1230 (trade name)], and the length × width is 144 mm.
It was cut into strips of × 42 mm.

A polyimide tape having a thickness of 50 μm and a width of 3 mm was attached to both sides of the active material layer application position of the positive electrode and the lead portion so as to prevent short-circuit and maintain the strength of the terminal. In addition, after covering all surfaces of the portion used for welding of the terminal with a thermal release tape from which the adhesiveness of the adhesive surface is lost due to heat, the surface of the polybutylene terephthalate nonwoven fabric is located on the left side of the longitudinal center portion. After mounting, the right side is folded back to cover the positive electrode, and both sides in the width direction are heat-sealed [trade name: POLYLER, Fuji Impulse
(Manufactured by Co., Ltd.), and a polybutylene terephthalate nonwoven fabric as a support was formed into a bag, and both were brought into close contact with each other to integrate the positive electrode and the support. This integrated product was immersed in the gelling component-containing electrolyte for 1 minute under reduced pressure to hold the gelling component-containing electrolyte in the positive electrode unit, and then placed in a polyethylene bag and sealed. Next, from both sides of the polyethylene bag, Fusion UV Systems Japan
Using an ultraviolet irradiator manufactured by Co., Ltd., the ultraviolet light was applied to 1 W / cm ²
Irradiation was performed for 10 seconds at an illuminance of 10 to polymerize the monomer components in the electrolytic solution, and the electrolytic solution was gelled to obtain a gel polymer electrolyte. The integrated body of the polymer electrolyte layer and the positive electrode, which has been gelled to retain the gel polymer electrolyte, is taken out of the bag, and the terminal portion is blown with hot air at 150 ° C. to peel off the thermal release tape from the terminal portion, and the polymer electrolyte is removed. A holding positive electrode unit was obtained.

Preparation of negative electrode A containing polymer electrolyte: Like the positive electrode, a polyimide tape having a thickness of 50 μm and a width of 3 mm is attached to both sides of the negative electrode A so as to straddle the active material application position and the lead, thereby preventing short circuit. And the strength of the terminals was maintained. In addition, all surfaces of the part used for welding the terminals
After covering with a heat-releasing tape from which the adhesiveness of the adhesive surface is lost by heat, and immersing in the gelling component-containing electrolyte for 1 minute under reduced pressure to hold the gelling component-containing electrolyte, Placed in a bag and sealed. Next, from both sides of the polyethylene bag, Fusion UV Systems Japan
Using an ultraviolet irradiator manufactured by Co., Ltd., the ultraviolet light was applied to 1 W / cm ²
Irradiation was performed for 10 seconds at an illuminance of 10 to polymerize the monomer components in the electrolytic solution, and the electrolytic solution was gelled to obtain a gel polymer electrolyte. After the gelled gel electrolyte was held, the negative electrode A was taken out of the bag, and 15
By blowing hot air of 0 ° C., the thermal release tape was peeled off from the terminal portion, and a negative electrode A containing a polymer electrolyte was obtained.

Preparation of a negative electrode B containing a polymer electrolyte: As in the case of the negative electrode A, a polyimide tape having a thickness of 50 μm and a width of 3 mm is attached to both sides of the negative electrode B so as to straddle the active material application position and the lead portion. Prevention and maintenance of terminal strength. In addition, the entire surface of the portion used for welding the terminal is covered with a heat-peeling tape that loses the adhesiveness of the adhesive surface due to heat, and immersed in the gelled component-containing electrolyte for 1 minute under reduced pressure to obtain a gel. After holding the chemical component-containing electrolytic solution, it was placed in a polyethylene bag and sealed. Next, from the outside of the polyethylene bag corresponding to the active material layer forming surface, ultraviolet rays were irradiated for 10 seconds at an illuminance of 1 W / cm ² using an ultraviolet irradiation device manufactured by Fusion UV Systems Japan Co., Ltd.
The monomer component in the electrolytic solution was polymerized, and the electrolytic solution was gelled to obtain a gel polymer electrolyte. The negative electrode B, which was gelled to hold the gel polymer electrolyte, was taken out of the bag, and the terminal portion was blown with hot air at 150 ° C. to peel off the thermal release tape from the terminal portion, thereby obtaining a polymer electrolyte-containing negative electrode B.

The five polymer electrolyte holding positive electrode units C and the polymer electrolyte holding negative electrode A
(Negative electrode A) 4 sheets and negative electrode B holding polymer electrolyte
(Negative electrode B) Two sheets were prepared, and as shown in FIG. 4 (which schematically shows the cross-sectional structure of the laminated electrode group),
The polymer electrolyte holding negative electrode B, the polymer electrolyte holding positive electrode unit C, the polymer electrolyte holding negative electrode A, the polymer electrolyte holding positive electrode unit C,..., The polymer electrolyte holding positive electrode unit C, and the polymer electrolyte holding negative electrode B are stacked in this order to form a laminated electrode group. obtain.

At this time, the two sheets of the polymer electrolyte holding negative electrode B
Are placed toward the center of the electrode group. That is, the current collectors of the polymer electrolyte holding negative electrode B are all directed to the outermost layer. The obtained laminated electrode group was packaged with a package consisting of a laminate film having a three-layer structure of a polyester film-aluminum film-modified polyolefin film to prepare a polymer electrolyte battery.

FIG. 5 (a plan view schematically showing the stacked battery) shows the obtained stacked battery. In the figure, reference numeral 8 denotes a positive electrode terminal, 9 denotes a negative electrode terminal, 6 denotes a positive electrode, 7 denotes a negative electrode, and 10 denotes a sealing portion of an exterior body. In this figure, a part of the exterior body is broken for easy understanding of the internal structure. The positive electrode terminal 8 and the negative electrode terminal 9 are connected to the positive electrode lead portion 8 'and the negative electrode lead portion 9' by melting, and are drawn out.

[0051]

As described above, according to the present invention, a battery having a high capacity density can be manufactured without deteriorating the workability in assembling the battery.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a cross-sectional structure of a stacked electrode group.

FIG. 2 is a schematic diagram showing a cross-sectional structure of an improved stacked electrode group.

FIG. 3 is a plan view schematically showing a state in which electrodes are overlapped.

FIG. 4 is a cross-sectional view schematically illustrating a stacked electrode group according to an example of the present invention.

FIG. 5 is a plan view schematically showing a battery obtained in an example of the present invention.

[Explanation of symbols]

 6 Positive electrode 7 Negative electrode 8 Lead 9 Lead 8 'Positive terminal 9' Negative terminal

Continuation of the front page (72) Inventor Osamu Ishida 1-88 Ushitora, Ibaraki-shi, Osaka F-term in Hitachi Maxell Co., Ltd. 5H011 AA09 KK01 5H022 AA09 CC08 CC12 5H029 AK03 AL07 AM00 AM03 AM04 AM07 AM16 HJ04 HJ12

Claims (2)

[Claims] 1. A positive electrode having a positive electrode mixture layer formed on a current collector, and a negative electrode having a negative electrode mixture layer formed on a current collector,
A laminated polymer electrolyte battery in which a laminated electrode group laminated with a polymer electrolyte layer interposed therebetween is packaged with a package, and the upper and lower outermost electrodes constituting the laminated electrode group have the same polarity, and A laminated polymer electrolyte battery, wherein a lead portion of the electrode is formed at the center in the electrode width direction. 2. The stacked polymer electrolyte battery according to claim 1, wherein the upper and lower outermost electrode active material layers are formed only on one surface of the current collector.