JP2000188130A - Polymer electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce internal resistance and to improve a load characteristic by surrounding at least one electrode of a positive electrode and a negative electrode with a support made of a porous sheet such as a nonwoven fabric to form an integrated object of the electrode and the support, and using a gelatinous polymer electrolyte gelatinized by impregnating the integrated object with an electrolyte containing a gelatinized component. SOLUTION: For integrating an electrode and a support, the electrode is stored in the bag-like support to be surrounded by the support, or the electrode can be pinched by one or two strip-like supports to be surrounded by the supports. A negative electrode is normally made larger than a positive electrode to prevent the occurrence of dendrite and to ensure safety, the size of the support can be made smaller when the positive electrode is surrounded by the support than when the negative electrode is surrounded by the support, thus a battery capacity can be increased. When the negative electrode is surrounded by the support, the boundary face state between the negative electrode and a gelatinous polymer electrolyte can be made homogeneous, thus the polarization of the negative electrode at the time of a reaction can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polymer electrolyte battery, and more particularly, to a polymer electrolyte battery particularly suitable for use in portable equipment, 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. In particular, batteries using polymer electrolytes have excellent safety and storage properties including leak resistance,
In addition, because it is thin and flexible, it can be designed to match the shape of the device.

[0003] This polymer electrolyte battery usually uses a laminate film having an aluminum film as a core material as an outer package, and a unit cell in which a thin sheet-like electrode and a sheet-like polymer electrolyte layer are laminated is packaged with the above outer package. By doing so, a thin battery is completed.

[0004]

In the polymer electrolyte battery, since the electrodes and the polymer electrolyte layer essentially do not contain a free liquid, there is essentially no need for a separator, but the battery characteristics are improved. For this reason, the polymer electrolyte is not a solid electrolyte but a gel polymer electrolyte.

Since the gel polymer electrolyte is softer and has a lower physical strength than the solid electrolyte, if the gel polymer electrolyte alone is used to separate the electrodes, the electrolyte layer is broken when pressed or bent. May cause a short circuit. For this reason, non-woven fabrics have been used as a support for gel polymer electrolytes.However, due to the manufacturing method, it is difficult to produce a uniform and thin non-woven fabric. Even if it does, the strength is not sufficient, it is very difficult to handle it alone, and the workability at the time of battery assembly is reduced. For this reason, a nonwoven fabric having a certain thickness must be used, and as a result, the thickness of the gel polymer electrolyte layer becomes thicker, the internal resistance of the battery increases, and the load characteristics deteriorate. Was.

Accordingly, the present invention solves the above-mentioned problems in the prior art, and maintains the strength even when the thickness of the gel polymer electrolyte is reduced, so that the internal resistance is reduced and the load is reduced. An object of the present invention is to provide a polymer electrolyte battery having excellent characteristics.

[0007]

According to the present invention, 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 impregnated with an electrolytic solution containing a gelling component. This problem has been solved by gelation.

That is, the present invention provides a polymer electrolyte battery having a positive electrode, a negative electrode and a gel polymer electrolyte, wherein at least one of the positive electrode and the negative electrode is surrounded by a support made of a porous sheet such as a nonwoven fabric. The present invention also relates to a polymer electrolyte battery characterized in that an electrode and a support are integrated, and the resultant is impregnated with an electrolytic solution containing a gelling component and gelled to form a gelled polymer electrolyte.

As described above, by surrounding the electrode with a support made of a porous sheet such as a nonwoven fabric and integrating the support with the electrode, even when the support made of a nonwoven fabric is thin and low in strength, In addition, the strength of the electrode can compensate for the insufficient strength of the support. Therefore, a thin support can be used, and as a result, the thickness of the gel polymer electrolyte can be reduced, the internal resistance is reduced, and the load characteristics are improved.

[0010] The thinner the porous sheet such as a non-woven fabric, the lower the strength and the more difficult it is to handle.
When it is used as a support and laminated with an electrode such as a positive electrode or a negative electrode, misalignment or wrinkles (wrinkles) are likely to occur and workability is reduced. Into a bag, and accommodate the electrode in it, or surround the electrode with the support by folding the strip-shaped support at the approximate center and sandwiching the electrode between them. Is integrated,
Occurrence of displacement and wrinkling of the support can be suppressed, and workability can be improved. In particular, when the support made of a porous sheet is formed into a bag, the occurrence of displacement and wrinkles can be suppressed efficiently, and workability can be significantly improved.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, at least one of a positive electrode and a negative electrode is surrounded by a support made of a porous sheet, and the electrode and the support are integrated with each other. In the case where the electrode is surrounded by the support by being accommodated in the support and the electrode and the support are integrated,
For example, the electrode is surrounded by the support by sandwiching the electrode between one or two strip-shaped supports, and the electrode and the support are integrated. Furthermore, in the case where the latter electrode is sandwiched between strip-shaped supports to surround the electrode with the support, one strip-shaped support is folded at substantially the center thereof and the electrode is sandwiched between the supports. In some cases, the electrode is surrounded by the support, and in another case, two strip-shaped supports are overlapped, one end is sealed, and the electrode is sandwiched between the supports to surround the electrode. .

In the present invention, as the porous sheet serving as a support for the gel 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 is easily impregnated with an electrolytic solution containing a gelling component, the nonwoven fabric is often used as a support in the present invention. As this nonwoven fabric, for example, the basis weight is 12 g / m ² and the thickness is 30 μm.
Such a very thin nonwoven fabric can be used.

Such a non-woven fabric has a low mechanical strength including tensile strength because of its thinness, and is difficult to handle alone. However, for example, the non-woven fabric is formed into a bag and the electrodes are accommodated in the bag-shaped non-woven fabric. By surrounding and integrating the nonwoven fabric with the electrode, the insufficient strength of the nonwoven fabric can be compensated for by the strength of the electrode. 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 Insufficient strength can be compensated, and workability during battery assembly can be improved, internal resistance can be reduced, and load characteristics can be improved. However, if the flat nonwoven fabric is merely stacked on the electrode and the electrode is not wrapped with the nonwoven fabric, the above-described effects cannot be obtained. 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 is surrounded by the support made of a porous sheet such as a nonwoven fabric, and the electrode and the support are integrated, and the electrode is impregnated with an electrolytic solution containing a gelling component to gel. Thereby, the adhesion between the electrode and the gel polymer electrolyte is better than when the electrode and the gel polymer electrolyte layer are separately gelled and laminated as the electrode and the gel polymer electrolyte layer, and bubbles, foreign substances, etc. are interposed between the layers. As a result, the ion transfer at the interface becomes smooth, and the reactivity between the positive and negative electrodes is improved. 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 a support and the electrode and the support may be integrated. In this case, the positive electrode is surrounded by the support and When the anode and the support are integrated, the battery capacity can be increased as compared with the case where the negative electrode is surrounded by the support. That is, usually, the negative electrode is generally made larger than the positive electrode in order to prevent the generation of dendrite and to ensure safety, so if the positive electrode is surrounded by the support, the negative electrode is surrounded by the support. Can be reduced in size, so that
The battery capacity can be increased. Further, when the negative electrode is surrounded by the support and the negative electrode and the support are integrated, the interface state between the negative electrode and the gel polymer electrolyte can be made uniform, so that the negative electrode is inferior in reactivity to the positive electrode. Can reduce polarization during the reaction.

Further, if both the positive electrode and the negative electrode are surrounded by a support, the thickness of the support is increased by an amount corresponding to that, but the electrodes and the gel polymer electrolyte layer are integrated. Also, the polarization can be reduced, and the reaction at the time of charging / discharging can proceed smoothly, so that the load characteristics can be greatly improved.

In the present invention, the integration of the electrode and the support means that the electrode and the support are brought into close contact with each other without bubbles or foreign matter between the electrode and the support. It does not mean that it is adhered to.

When the support made of a porous sheet such as the above nonwoven fabric is formed into a bag shape, if the bag shape is described as, for example, a rectangular shape, usually, one side is 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.

In storing the electrode in the bag-shaped support, it is not required that the support is formed in a bag-like shape in advance, and the electrode is formed in a strip-shaped support (for example, when the length is 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, as is apparent from the above description, when the support is folded at substantially the center and the electrode is sandwiched between the supports, the electrode is inserted between the support after the center of the support is folded. It is not necessary, and as in the above, the electrode is a strip-shaped support (for example, the length is twice or more the length of the electrode,
A strip-shaped support having 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 turned back, whereby the electrode is sandwiched between the supports. What is necessary is just to be in a state. Also, when two strip-shaped supports are overlapped, one end thereof is sealed, and the electrode is sandwiched between them, it is not necessary to seal the electrodes in advance, and the electrode is formed in one strip-shaped support ( For example, it is placed on a strip-shaped support whose length is longer than the length of the electrode and whose width is wider than the width of the electrode), another strip-shaped support is placed thereon, and the support May be sealed continuously or discontinuously so that the electrode is sandwiched between the supports.

As the electrolytic solution, for example, dimethyl carbonate
, Diethyl carbonate, methyl ethyl carbonate
Salt, methyl propionate, ethylene carbonate,
Ropylene carbonate, butylene carbonate, gamma
Butyrolactone, ethylene glycol sulfite,
1,2-dimethoxyethane, 1,3-dioxolan, te
Trahydrofuran, 2-methyl-tetrahydrofuran,
In an organic solvent such as diethyl ether, for example, LiCl
O_Four, LiPF₆, LiBF_Four, LiAsF₆, LiS
bF₆, LiCF_ThreeSO_Three, LiC_FourF₉SO_Three, Li
CF_ThreeCO_Two, Li_TwoC_TwoF_Four(SO_Three)_Two, LiN
(CF_ThreeSO_Two)_Two, LiC (CF_ThreeSO _Two)_Three, Li
C_nF_{2n + 1}SO_Three(N ≧ 2), LiN (RfOSO_Two)
_Two[Where Rf is a fluoroalkyl group]
Used by dissolving
You. The concentration of the inorganic ion salt in the electrolytic solution is set to 0.1.
5 to 1.5 mol / l, especially 0.9 to 1.25 mol / l
l is preferred.

In the present invention, the gelling component refers to a component that gels an electrolytic solution. Examples of such a gelling component include polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, and vinylidene fluoride-hexafluoride. A linear polymer such as a propylene copolymer is dissolved in an electrolyte by heating, and then cooled to form a polymer that gels the electrolyte or a double bond that can be polymerized by actinic rays. A crosslinkable composition containing, as a main component, a monomer or prepolymer containing two or more molecules per molecule is exemplified.

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.

Examples of the monomer having three double bonds polymerizable by actinic ray per molecule (trifunctional crosslinkable monomer) include, for example, tris (2-hydroxyethyl) isocyanurate triacrylate and trimethylolpropane triacrylate. Trifunctional acrylates such as acrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate, caprolactone-modified trimethylolpropane triacrylate, and trifunctional methacrylates similar to the above acrylates And the like.

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.

In addition, a double bond polymerizable with actinic rays is
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 above monomer or prepolymer having two or more double bonds polymerizable by actinic light per molecule may be used as a main component, for example, 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 means that the above-mentioned crosslinkable composition is polymerized by actinic light. Monomers or prepolymers that have only two or more possible double bonds per molecule, and monomers or prepolymers that have two or more double bonds per molecule that can be polymerized with a monofunctional monomer or the like by actinic light When used together with a monofunctional monomer or the like having a monomer or prepolymer having two or more double bonds per molecule which can be polymerized by actinic light as the latter, Of a monomer or 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.

[0032]

Next, the present invention will be described in detail with reference to examples and comparative examples. However, the present invention is not limited only to those illustrated in the embodiments. In Examples and Comparative Examples, a non-woven fabric was used as a support for the gel polymer electrolyte, the non-woven fabric was formed into a bag, the electrodes were accommodated in the bag-shaped support, and the electrodes were wrapped with the non-woven fabric to form a gel. (Examples 1 to 3), a non-woven fabric that is folded at almost the center, an electrode is sandwiched between the non-woven fabrics, the electrodes are wrapped in a non-woven fabric, and gelled (Example 4). Various batteries such as (Comparative Example 1) and a non-woven fabric stacked with an electrode and gelled (Comparative Example 2) were prepared, and the workability, internal resistance, load characteristics, battery thickness, and the like during battery assembly were measured. Measure, but prior to their explanation,
The production of the positive electrode and the negative electrode will be described.

Preparation of positive electrode: LiCoO as positive electrode active material
₂ 80 parts by weight, acetylene black 10 as a conductive additive
The mixture was uniformly mixed with 10 parts by weight of polyvinylidene fluoride as a binder 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 then calendered to adjust the thickness of the positive electrode mixture layer so that the total thickness became 130 μm. The positive electrode was manufactured by cutting into a size of 40 mm. However, in producing the positive electrode, the paste containing the positive electrode mixture was not applied to a part of the aluminum foil, leaving an exposed portion of the aluminum foil, and the exposed portion was used as a connection portion with a positive electrode terminal as an external terminal.

Preparation of negative electrode: 90 parts by weight of graphite as a negative electrode active material and 10 parts by weight of polyvinylidene fluoride were uniformly mixed using N-methylpyrrolidone as a solvent to prepare a negative electrode mixture-containing paste. The paste was applied to both sides of a 10 μm thick copper foil serving as a current collector, dried, and then calendered to adjust the thickness of the negative electrode mixture layer so that the total thickness became 130 μm. A negative electrode was prepared by cutting to dimensions. However, in producing the negative electrode, the negative electrode mixture-containing paste was not applied to part of the copper foil, leaving an exposed portion of the copper foil, and the exposed portion was used as a connection portion with a negative electrode terminal as an external terminal.

Preparation of electrolytic solution containing gelling component: volume ratio of propylene carbonate to ethylene carbonate 1: 1
As an initiator, 2,4,4 was dissolved in an electrolyte prepared by dissolving 1.22 mol / l of LiPF _{6 in} a mixed solvent of
6-trimethylbenzoyldiphenylphosphine oxide (trade name: Lucirin TPO, manufactured by BSF Japan Co., Ltd.)
Wt% and dissolved therein, and dipentaerythritol hexaacrylate was added to the mixture at a concentration of 6 minutes before the start of use.
The mixture was added and mixed so as to obtain a weight percent, thereby preparing 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.

Example 1 In Example 1, both the positive electrode and the negative electrode were wrapped in a nonwoven fabric serving as a support in advance, and the electrode and the support were integrated.
Each of them is impregnated with a gelling component-containing electrolytic solution and gelled to form a gel polymer electrolyte. First, a process of integrating an electrode and a support into an electrode unit will be described.

Preparation of the positive electrode unit: A polybutylene terephthalate nonwoven fabric having a thickness of 30 μm and a basis weight of 12 g / m ² [MB1230 (trade name, manufactured by NKK)] was used as a support.
This was cut into strips measuring 75 mm × 90 mm in length × width.

In a portion near the terminal portion of the positive electrode, a thickness of 50 μm
An imide tape having a width of 3 mm and a width of 3 mm was adhered from both sides 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 heat release tape from which the adhesiveness of the adhesive surface is lost by heat, the positive electrode is leftward from the center in the length direction of the polybutylene terephthalate nonwoven fabric. After turning over the right side to cover the positive electrode, both sides in the width direction are sealed with a heat sealer (trade name: POLYLER, manufactured by Fuji Impulse Co., Ltd.) The non-woven fabric of polybutylene terephthalate was made into a bag shape, and the two were brought into close contact with each other to integrate the positive electrode and the support into a positive electrode unit.

Fabrication of the negative electrode unit: A polyimide tape having a thickness of 50 μm and a width of 3 mm was adhered to both sides of the negative electrode near the terminal to prevent short-circuit and maintain the strength of the terminal. In addition, the entire surface of the portion used for welding the terminal was covered with a heat-peeling tape from which the adhesiveness of the adhesive surface was lost by heat. Then, as in the case of the positive electrode, a bag-shaped polybutylene terephthalate nonwoven fabric was accommodated in the negative electrode, the two were brought into close contact with each other, and the negative electrode and the support were integrated to form a negative electrode unit.

Each of the positive electrode unit and the negative electrode unit was immersed in the above-mentioned gelling component-containing electrolytic solution for 1 minute under reduced pressure to impregnate the positive electrode unit and the negative electrode unit with the gelling component-containing electrolytic solution. Placed in a bag and sealed.

Next, ultraviolet light was applied to both sides of the polyethylene bag containing the electrode unit using an ultraviolet irradiation device manufactured by Fusion UV Systems Japan KK.
Irradiation was performed for 10 seconds at an illuminance of W / cm ² to polymerize the monomer components in the electrolytic solution and gel the electrolytic solution to obtain a gel polymer electrolyte.

The positive electrode unit and the negative electrode unit, which were gelled and held the gel polymer electrolyte as described above, were 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. After that, the above-mentioned gelled polymer electrolyte holding positive electrode unit and the gelled polymer electrolyte holding negative electrode unit are laminated to form a unit cell, which is made of a three-layer laminate film of a polyester film-aluminum film-modified polyolefin film. To produce a polymer electrolyte battery.

The schematic structure of the battery of Example 1 will be described with reference to FIG. 1. Reference numeral 10 denotes a gelled polymer electrolyte holding positive electrode unit, and reference numeral 20 denotes a gelled polymer electrolyte holding negative electrode unit.

As shown in FIG. 2, the gel-type polymer electrolyte holding positive electrode unit 10 comprises a positive electrode 1 and a bag-like support 3.
a, and the positive electrode 1 and the support 3a are integrated with each other, and then impregnated with an electrolytic solution containing a gelling component. In this state, the monomer component is polymerized by irradiating ultraviolet rays, and the electrolytic solution is gelled to form a gel. This was constituted by using the polymer electrolyte 3. Note that FIG. 2 schematically shows the gelled polymer electrolyte holding positive electrode unit 10 and shows the gelled polymer electrolyte 3 as if it were formed around the support 3a. When the positive electrode unit is impregnated with the gelling component-containing electrolytic solution, the gelling component-containing electrolytic solution penetrates into the inside of the support made of a porous nonwoven fabric, and further penetrates into the pores inside the positive electrode. ,
Thereupon, polymerization and gelation are performed to form a gel-like polymer electrolyte. However, the gel polymer electrolyte at that portion is not shown in FIG.

As shown in FIG. 3, the gelled polymer electrolyte holding negative electrode unit 20 accommodates the negative electrode 2 in a bag-shaped support 3a and integrates the negative electrode 2 with the support 3a.
The gelled polymer electrolyte 3 in the gelled polymer electrolyte holding negative electrode unit 20 is formed by impregnating the gelled component-containing electrolyte, polymerizing the monomer component, and gelling to form the gelled polymer electrolyte 3. Is also the same as that described in relation to the gelled polymer electrolyte holding positive electrode unit 10 described above.

In FIG. 1, reference numeral 4 denotes an outer package made of the above-mentioned laminated film. The outer package 4 is formed by laminating the gel polymer electrolyte holding cathode unit 10 and the gel polymer electrolyte holding anode unit 20. The positive electrode terminal 5 is drawn out of the exterior body 4 from the positive electrode of the gelled polymer electrolyte holding positive electrode unit 10, and the negative electrode terminal 6 is drawn from the negative electrode of the gelled polymer electrolyte holding negative electrode unit 20. Are drawn out to form a battery.

The thickness of the battery of Example 1, workability in assembling the battery, the measurement results of the internal resistance and load characteristics, and the like are shown in Table 1 below together with those of Examples 2 to 4 and Comparative Examples 1 and 2 described later. Show.

Example 2 The positive electrode side was a gelled polymer electrolyte holding positive electrode unit in the same manner as in Example 1, and the negative electrode side was a negative electrode prepared prior to the example without integration with the support or gelation. A polymer electrolyte battery was produced in the same manner as in Example 1, except that the battery was used as it was.

FIG. 4 shows a schematic structure of the battery of the second embodiment. In FIG. 4, reference numeral 10 denotes a gelled polymer electrolyte-holding positive electrode unit as in the case of the battery of Example 1 shown in FIG. 1, and its detailed structure is the same as that shown in FIG. Others are the same as those of the battery of Example 1 shown in FIG.

Example 3 On the positive electrode side, the positive electrode prepared prior to this example was used without any integration or gelation with the support, and on the negative electrode side, a gelled polymer electrolyte holding negative electrode was used in the same manner as in Example 1. A polymer electrolyte battery was manufactured in the same manner as in Example 1 except that the battery was a unit.

FIG. 5 shows a schematic structure of the battery of the third embodiment. In FIG. 5, 1 is a positive electrode, 20 is a negative electrode unit holding a gel polymer electrolyte, and the detailed structure is shown in FIG.
The other is the same as the case of the battery of Example 1 shown in FIG.

Example 4 Instead of accommodating in a bag-shaped support and wrapping it in a support as in Example 1, a strip-shaped support similar to that in Example 1 was used for both the positive electrode and the negative electrode. Turned back at the section, during which the positive electrode,
Same as Example 1 except that the negative electrode was separately sandwiched and wrapped with a support, and the support and the positive electrode and the support and the negative electrode were integrated as they were (that is, without forming a bag shape as in Example 1). The polymer electrolyte was impregnated with a gelling component-containing electrolyte, gelled, and the like, to produce a polymer electrolyte battery.

Comparative Example 1 On both the positive electrode side and the negative electrode side, the positive electrode and the negative electrode produced prior to the example were used as they were without being integrated with the support or gelled, and directly (ie, Without being integrated with the electrode as in Example 1, the same gelling component-containing electrolytic solution as in Example 1 was impregnated, and gelled as in Example 1 to produce a sheet-like gel polymer electrolyte. . Then, a negative electrode and a positive electrode were laminated with the obtained sheet-like gel-like polymer electrolyte interposed therebetween to produce a unit cell, which was packaged with a package 4 made of a laminate film as in Example 1. Thus, a polymer electrolyte battery was manufactured.

FIG. 6 shows a schematic structure of the battery of Comparative Example 1. In FIG. 6, 1 is a positive electrode, 2 is a negative electrode, 3 is a gel-like polymer electrolyte, which is formed in a sheet shape using a nonwoven fabric as a support, and is disposed between the positive electrode 1 and the negative electrode 2 in that state. are doing. Others are the same as the case of the battery of Example 1 shown in FIG.

Comparative Example 2 A non-woven fabric similar to that of Example 1 was used as a support, and a support made of the non-woven fabric was disposed above and below the positive electrode and the negative electrode to form a positive electrode unit and a negative electrode unit. A similar electrolyte solution containing a gelling component was impregnated in the same manner as in Example 1, and a polymer electrolyte battery was fabricated in the same manner as in Example 1 except for the above.

With respect to the batteries of Examples 1 to 4 and Comparative Examples 1 and 2, the battery thickness was measured, the internal resistance and load characteristics were examined, and the workability during battery assembly was evaluated.
Table 1 shows the results.

The height of the battery from the bottom surface to the top surface of the battery was measured with calipers. The internal resistance uses an LCR meter,
It measured by the alternating current method (1 kHz). The load characteristics are 4.2
V, charged at a constant current and a constant voltage of 0.2 C for 8 hours, discharged at a current density of 1 C and 0.2 C to 2.75 V, respectively, measured the discharge capacity, and measured the discharge capacity when discharged at a current density of 1 C. Ratio divided by discharge capacity when discharging at a density of 0.2 C [(discharge capacity at 1 C / discharge capacity at 0.2 C) ×
100]. In addition, the evaluation of workability at the time of assembling the battery is symbolized and displayed according to the following criteria.

A: There is no generation of wrinkles or mixing of bubbles between layers. 〇: The electrode is displaced with respect to the support, but after gelation, no wrinkles are generated and no bubbles are mixed between the layers. ×: Wrinkles or bubbles were generated on the support when superposed.

[0059]

[Table 1]

As is clear from the results shown in Table 1, Examples 1 to 4 have low internal resistance and excellent load characteristics,
Moreover, the workability during battery assembly was excellent. This is based on the fact that, in these examples, the electrode and the support were integrated in advance, impregnated with an electrolytic solution containing a gelling component, and gelled to form a gel polymer electrolyte.

On the other hand, in Comparative Example 1 in which a positive electrode, a negative electrode and a sheet-like gel polymer electrolyte which were separately prepared according to the prior art were laminated in the order of a negative electrode, a sheet-like gel polymer electrolyte and a positive electrode, The internal resistance was high, the load characteristics were inferior to those of Examples 1-4, the workability during battery assembly was poor, and the support had wrinkles. In Comparative Example 2 in which the sheet-shaped support was disposed above and below each of the positive electrode and the negative electrode without integrating the electrode and the support, the internal resistance was high, and the load characteristics were low.
4 and the workability during battery assembly was poor, and the support was wrinkled.

[0062]

As described above, according to the present invention, it is possible to provide a polymer electrolyte battery having excellent workability in assembling the battery, low internal resistance, and excellent load characteristics.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a polymer electrolyte battery according to Example 1 of the present invention.

FIG. 2 is a cross-sectional view schematically showing a gelled polymer electrolyte holding positive electrode unit of the polymer electrolyte battery according to Example 1 of the present invention.

FIG. 3 is a cross-sectional view schematically showing a gelled polymer electrolyte holding negative electrode unit of the polymer electrolyte battery according to Example 1 of the present invention.

FIG. 4 is a cross-sectional view schematically showing a polymer electrolyte battery according to Example 2 of the present invention.

FIG. 5 is a cross-sectional view schematically showing a polymer electrolyte battery according to Example 3 of the present invention.

FIG. 6 is a cross-sectional view schematically showing a polymer electrolyte battery of Comparative Example 1 based on the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Negative electrode 3 Gel polymer electrolyte 3a Support 4 Outer body 5 Positive electrode terminal 6 Negative terminal 10 Gel polymer electrolyte holding positive electrode unit 20 Gel polymer electrolyte holding negative electrode unit

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Taku Sugiyama 1-88 Ushitora, Ibaraki City, Osaka Prefecture Inside Hitachi Maxell Co., Ltd. (72) Eri Yokoyama 1-188 Ushitora, Ibaraki City, Osaka Prefecture F-term in Hitachi Maxell, Ltd. (reference) 5H011 AA00 CC10 HH13 5H014 AA02 AA07 BB08 CC01 EE01 5H029 AJ01 AJ06 AK03 AL07 AM00 AM03 AM04 AM05 AM16 BJ04 BJ13 CJ00 CJ01 CJ23 DJ04 DJ06 DJ15 EJ12 HJ12

Claims (6)

[Claims] 1. A polymer electrolyte battery comprising a positive electrode, a negative electrode, and a gel polymer electrolyte, wherein at least one of the positive electrode and the negative electrode is surrounded by a support made of a porous sheet, and the electrode and the support are integrated. A polymer electrolyte battery characterized in that the polymer electrolyte battery is formed into a gel polymer electrolyte by forming a gel, and then impregnating with an electrolyte solution containing a gelling component to form a gel. 2. The polymer electrolyte battery according to claim 1, wherein at least one of the positive electrode and the negative electrode is accommodated in a bag-shaped support, the electrodes are surrounded by the support, and the electrodes and the support are integrated. 3. An electrode is surrounded by a support by sandwiching at least one electrode of a positive electrode or a negative electrode between one or two strip-shaped supports, and the electrode and the support are integrated. The polymer electrolyte battery according to the above. 4. The polymer electrolyte battery according to claim 1, wherein the electrode surrounded by the support is a positive electrode. 5. The polymer electrolyte battery according to claim 1, wherein the electrode surrounded by the support is a negative electrode. 6. The polymer electrolyte battery according to claim 1, wherein the electrodes surrounded by the support are a positive electrode and a negative electrode.