JPH0864200A - Electrode for secondary battery and secondary battery having the electrode - Google Patents

Abstract

PURPOSE: To provide an electrode with high flexibility and high adhesion with a substrate by containing a plasticizer in a polymer material in the electrode having the polymer material conducting at least one kind of electrochemical oxidation/reduction reaction. CONSTITUTION: In an electrode for a battery having a material conducting at least one kind of electrochemical oxidation/reduction reaction (an active material 1), a plasticizer is contained in the active material 1. The kind of the plasticizer is not limited as far as it can plasticize the active material. However, in order that the plasticizer is left in the active material 1 in a drying process and the function to increase the adhesion with a substrate is sufficiently realized, a solvent having a boiling point of 200 deg.C or higher and a vapor pressure of 5mm Hg or less (at 85 deg.C) is preferable. As the solvent, it is preferable that the solvent is easily oxidized/reduced by electrode reaction, does not adversely affect the battery performance even if dissolved in an electrolyte, and soluble in an electrolyte salt. As the solvent, dibutyl phthalate, di-n-octyl phthalate and the like are used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a secondary battery having high strength, flexibility, and high energy density, and an electrode used for the battery.

[0002]

2. Description of the Related Art A secondary battery (hereinafter abbreviated as a lithium secondary battery) based on the movement of lithium ions between a positive electrode and a negative electrode is a lead-acid battery or a nickel battery.
Since it has a simpler construction than a cadmium battery and has the highest electromotive force in theory, it has received a great deal of attention. And
In the 1970s, a secondary battery using metallic lithium as a negative electrode active material and titanium disulfide as a positive electrode active material was commercialized, and in 1987, a secondary battery in which the positive electrode active material of the secondary battery was changed to molybdenum disulfide was commercially available. Development is progressing by the time. Further, in 1987, a secondary battery using metallic lithium as a negative electrode active material and polyaniline as a positive electrode active material was put into practical use. In addition to this, development of a lithium secondary battery using a conductive polymer as an electrode is in progress. However, it cannot be said that the prototype battery currently announced makes full use of the capability of the lithium secondary battery, and one of the main causes is considered to be the poor electrode performance. Positive electrode active materials used in lithium secondary batteries include titanium, molybdenum, niobium, chromium,
In addition to chalcogen compounds such as manganese, vanadium and cobalt, conductive organic polymer compounds such as polyaniline and polypyrrole are being studied. However, when the above chalcogen compound is used as the positive electrode, the diffusion rate of chaos in the electrode during the electrode reaction during charging / discharging is slow, so that rapid charging / discharging
Discharge is difficult and reversibility is poor in over discharge. In addition, when an inorganic active material is used as an electrode, a binder is used for molding, but when using commonly used Teflon powder etc. as a binder, the pressure / heat molding method provides sufficient mechanical strength. It is difficult to get a large electrode.

As the binder for forming electrodes, it is desirable to use a binder in the form of a fine powder having a high melting point, which is insoluble in the electrolyte solution and difficult to uniformly contact, and is generally a polyolefin-based binder such as polyethylene or Teflon. A fine powder of molecules is used. The fine particles of the inorganic active material are mixed well with the fine powder of the binder, and fixed by heating and pressurizing the fine particles of the lithium secondary battery.
Since the insertion and release of lithium cations into the active material crystals are repeated during discharge, the binder having no ability as an active material lowers the insertion and release efficiency of lithium cations, and the energy per unit capacity of the electrode is reduced. It also causes a decrease in efficiency.

A conductive polymer used as an electrode active material of a lithium secondary battery can take advantage of plastics in terms of molding and processing, and is 100% in a secondary battery using this as an electrode active material. High cycle characteristics can be exhibited even if the discharge of is repeated. However, in a secondary battery in which a conductive polymer is used as an electrode active material, there is a problem that the volume energy density is lowered due to the low density of the active material. On the other hand, it has also been attempted to reversibly insert / release anions into / from a conductive polymer to form a secondary battery by this electrode reaction. In this case, however, cations are taken in and out at the negative electrode. It is necessary to have enough electrolyte therein for the electrode reaction. Further, in this case, since the concentration of the electrolytic solution greatly changes with the charge / discharge reaction, the change of the liquid resistance and the like is large, and an excessive amount of the electrolytic solution is necessary for the smooth progress of the charge / discharge reaction. And, for these reasons, it is difficult to improve the volume energy density.

In order to eliminate the above-mentioned problems, Japanese Patent Laid-Open No. Sho 63-63
JP-A-102162 and JP-A-5-82120 disclose a method of forming a positive electrode with a conductive polymer and an inorganic chalcogen compound. However, in these applications, the positive electrode is formed only by mixing the above two in the form of powder, which cannot be said to be a method of sufficiently increasing the energy density. Further, in JP-A-2-220373, a coating film-forming liquid prepared by dissolving a conductive polyaniline in N-methylpyrrolidone is prepared, coated on a substrate for a support and dried to obtain a porous film. A secondary battery using the porous film as a positive electrode active material is disclosed. However, since the film obtained by this method uses polyaniline, which has a lower energy density per volume than the inorganic active material, as the active material, an electrode with a high energy density cannot be obtained, and the obtained coating film is hard and brittle, so it is flexible. Poor adhesion to the substrate.

There are several conventional methods for improving the adhesion between the film and the substrate. One is a method of roughening the surface of the substrate to bring it into close contact with the substrate. However, in this method, since only physical adhesion between the film and the substrate was enhanced, it was unavoidable that peeling occurred gradually due to repeated expansion and contraction of the active material. Secondly, an anchor layer having a composition close to that of the film may be provided between the substrate and the film. However, in this method, the anchor layer needs to be conductive in order to transfer electrons between the film and the substrate, which is subject to many restrictions. In addition, it is not possible to solve even peeling due to cracking of the thick film. As described above, it is difficult to obtain a secondary battery electrode having a high energy density by the conventional method, which can be said to hinder the development of an ideal secondary battery.

[0007]

An object of the present invention is to solve the above-mentioned problems of the prior art and to develop a high-strength, flexible and high-energy-density secondary battery and an electrode that can be used in the battery and achieve the purpose. To do.

[0008]

According to the present invention, there is provided an electrode for a battery, which comprises at least one kind of a polymeric material which exhibits an electrochemical redox reaction [hereinafter referred to as an active material (1)].
Relates to a secondary battery electrode containing a plasticizer. The inventors of the present invention have invented that the plasticizer added to the active material (1) remains in the electrode film to enhance the adhesion to the substrate in the drying step during the production of the electrode. It has arrived. The type of the plasticizer added to the active material (1) in the present invention is not particularly limited as long as it can plasticize the active material (1), but when the plasticizer is dried, the active material (1) is added. ), The vapor pressure is 5 mmH at a boiling point of 200 ° C. or higher in order to fully exert the function of enhancing the adhesion with the substrate.
The solvent is preferably g (85 ° C.) or less. In addition, these solvents have characteristics that they are not easily redox-reduced by an electrode reaction, that they do not adversely affect the battery performance even if they are dissolved in an electrolytic solution, or that they exhibit solubility in an electrolyte salt. Those having are preferred. Examples of the solvent include dibutyl phthalate (DBP), di-n-octyl phthalate (DnOP), di (2-phthalate).
At least one selected from the group consisting of ethylhexyl) (DOP), di (2-ethylhexyl) adipate (DOA), di (2-ethylhexyl) sebacate (DOS), and dibutyl sebacate.
The addition amount of the plasticizer employed in the present invention varies depending on the type of the plasticizer used, but is usually preferably in the range of 0.1 to 5 wt% with respect to the active material (1).
If it is 0.1 wt% or less, the effect of including the plasticizer cannot be expected so much, and if it exceeds 5 wt%, the adhesion to the substrate is rather deteriorated. Particularly preferably 0.2 to 2 w
t%. Further, a reactive plasticizer, for example, a plasticizer which is decomposed by receiving an oxidation-reduction (reaction) by an electrode reaction and adversely affecting the battery characteristics, exceeds 0.5 wt% of the battery using the electrode. 0.3 wt% or less is preferable because it significantly reduces the cycle life.

At least a part of the active material (1) used for forming the electrode of the present invention is electrochemically redox-reactive and has an ability as an electrode active material, and at the same time, it is insoluble in an electrolytic solution and is a polymer. It is a material that can bind each other. When this polymer is a conductive polymer, when an inorganic active material is blended, the inorganic active material is included in the polymer, and the entire periphery of the inorganic active material becomes conductive, so that the electrode material Is extremely preferable as Specific examples of the above-mentioned active material (1) used for electrode formation include conductive polymers such as polyacetylene, polypyrrole, polythiophene, and polyaniline; Redox active conductive materials such as polydiphenylbenzidine, polyvinylcarbazole, and polytriphenylamine. And the like. Further, a conventional electrode forming binder having no conductivity or electrochemical property, such as Teflon or polyethylene, may be used in combination with the polymer. However, if this amount is too large, the electrical properties of the polymer will not be exhibited, and therefore the electrode performance will be significantly reduced. The polymers having the above electrical characteristics may be used alone or in combination of two or more.

The polymer having the above-mentioned electrical characteristics used in the present invention is particularly advantageous in terms of electrode formation and the like when a solvent-soluble polymer is used. This is a dispersion liquid in which fine particles of an inorganic active material are dispersed in a solution of the polymer having electrical characteristics, or a liquid in which a small amount of Teflon fine powder or various additives is dispersed in this liquid is prepared. This is because an electrode formed by coating and drying the current collector is extremely preferable. Since the electrode is homogeneous and strong and is formed more densely than the electrode formed by heating and pressurization, a secondary battery with a small capacity and a high output can be obtained. In addition, since the inorganic active material is homogeneously included in the polymer in the electrode, the inorganic active material is protected by the polymer even when overcharged or overdischarged, and there is no problem such as capacity reduction. . Among the above polymers used for electrode formation, a polymer containing nitrogen is particularly suitable for the electrode material, and the polymer contains 10 ⁻⁵ S when doped with the electrolyte forming the battery. It exhibits an electric conductivity of / cm ² or more and is excellent in the diffusibility of electrolyte ions. In particular, polyaniline has a relatively large electric capacity per weight and can be charged and discharged comparatively stably, so it can be said that polyaniline is most suitable as the polymer for electrode formation of the present invention.

Further, in the present invention, the active material (1)
It is preferable that at least one kind of particulate inorganic active material [hereinafter referred to as active material (2)] is homogeneously dispersed in the matrix. The particulate active material (2) is preferably an active material having a plateau region in which the potential change is 1 V or less, preferably 0.8 V or less at a discharge amount of 100 mAh / g during discharge. With an active material in which the potential changes by 1 V or more at a discharge amount of 100 mAh / g, the discharge voltage range of the battery manufactured is too large and not practical. Specifically, V, C
Examples thereof include oxides of transition metals such as o, Mn, and Ni, or complex oxides of the above transition metals and alkali metals, and crystallinity is obtained in consideration of stable electrode potential, voltage flatness, and energy density. Vanadium oxide is preferred,
Particularly, vanadium pentoxide is preferable. The reason is that the potential flat portion of the discharge curve of crystalline vanadium pentoxide is relatively close to the electrode potential associated with the insertion and desorption of anions in the conductive polymer. However, the conductivity of vanadium pentoxide is poor, and even if its periphery is covered with the active material (1) and its conductivity is improved, if the particle size is large, the diffusion of ions within the particle will be rate-determining and the influence of voltage drop. Cannot be ignored.

As the method for combining the active materials (1) and (2), a suitable amount of the active materials (1) and (2) is sampled and sufficiently mixed, or a solvent in which the active material (1) is dissolved or partially dissolved. A method of thoroughly mixing the active materials (1) and (2) therein,
A method in which the active material (1) is chemically or electrochemically produced in the presence of the active material (2) to form a composite is preferably used. Particularly, in order to obtain a film with a high density on the substrate, is most desirable, and by applying the coating solution, a film in which the active material is uniformly and uniformly dispersed can be obtained. The active material (2) for an electrode active material has an average particle size of 10 μm or less, preferably 3 μm or less, and a maximum particle size of 30 μm or less, so that the active material (2) with the compound and the active material (1) forming an electrode are in close contact with each other. It is preferably 10 μm or less. When atomized, it adheres well to the polymer, and when forming the electrode with the coating liquid, the liquid becomes homogeneous and a uniform film is obtained, so problems such as the electrode falling off from the current collector are prevented. However, problems such as a decrease in the diffusion rate of electrolyte ions into the inorganic compound during the electrode reaction can be prevented. The active material (2) detailed above is 70% of the total weight of the electrode.
It may be added in an amount of about 95%. If the addition amount of the active material (2) exceeds 95% by weight, the binding ability of the electrode will be insufficient and it will be difficult to form the electrode. If it is less than 70% by weight, the amount of polymer having a low energy density will increase. The overall energy density is reduced.

The electrode of the present invention can be used as both a positive electrode and a negative electrode, but in general, it is often used as a positive electrode.
Metal lithium is often used for the negative electrode. When using the electrode as a positive electrode, a known additive that is added to the positive electrode of a secondary battery can be added. That is, if necessary, acetylene black, aniline black, activated carbon powder,
Conductive carbon powder such as graphite powder; powder of carbon body formed of polyacrylonitrile, pitch, cellulose, phenol resin, etc .; fine oxide powder composed of metal such as Ti, Sn, In; stainless steel, nickel, etc. Metal powder or fibrous material; and the like can be added as a conductive auxiliary agent. Similarly, in the case where the electrode is used as a negative electrode, the same known additives as the above-mentioned conductive additive can be added.

As described above, the electrode of the present invention is preferably formed into a coating film, and a polymer such as polyaniline is dissolved in a polar non-aqueous solvent such as polyalkylthiophene, dimethylformamide, N-methylpyrrolidone and tetrahydrofuran. , A fine powder of an inorganic active material or the like is well dispersed in this solution to prepare a dispersion, which is then coated on any substrate, preferably a current collector substrate with a wire bar or a blade coater, or It may be formed by applying after spraying and drying. In this case, the weight of the solid content in the coating liquid is preferably 20% or more of the weight of the solvent, and the viscosity of the coating liquid is 1%.
It is preferable that the pressure is 000 cpm or more and 10,000 cpm or less. If the viscosity is lower than 1000 cpm, the solid content of the inorganic active material or the like is likely to settle in the solution, and if the viscosity exceeds 10,000 cpm, the coating becomes difficult due to the high viscosity. A ball mill, a barren mill, or the like is used to disperse the solid content.
When polyaniline is used as the polymer, particularly good results are obtained when the concentration in the liquid is 8 to 15% by weight.

It is desirable that the above coating liquid is prepared and coated in an inert gas atmosphere in order to prevent the conductive polymer from being deteriorated. The dry coating thickness is 10 μm or more, preferably 20 to 100 μm. The electrode thus formed has a density of 1.8 g / cm ³ or more, preferably 2.2 g / cm ³ or more. The secondary battery of the present invention is composed of a positive electrode, a negative electrode, an electrolytic solution, and members such as a separator, a current collector, and partition walls. Then, the electrode of the present invention is used for the positive electrode, and in addition to the electrode of the present invention for the negative electrode, various materials capable of incorporating metal lithium or lithium between layers, for example, an intercalation type such as graphitized carbon body. A substance or the like is used. A solid electrolyte may be used instead of the electrolytic solution and the separator. The separator is preferably one having a low resistance to ion migration of the electrolyte solution and an excellent solution retention property. A glass fiber filter; a pore filter or a non-woven fabric formed of a polymer such as polyester, Teflon, polyflon, polypropylene; glass fiber and the above A nonwoven fabric made of a polymer; or the like is preferably used.

The electrolytic solution is a solution in which a lithium salt is dissolved in an organic solvent, and the organic solvent dissolves the lithium salt well and does not have to react with the electrode constituent substance or the lithium salt, but it is a solvent having a relatively large polarity. Is preferred. Specifically, propylene carbonate, ethylene carbonate, benzonitrile, acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, γ-butyrolactone, dioxolane, triethylphosphite, triethylphosphate, dimethylformamide, dimethylacetamide, dimethylsulfoxide, dioxane, dimethoxyethane,
Examples thereof include one or a mixture of two or more organic solvents such as polyethylene glycol, sulfolane, dichloroethane, chlorobenzene, nitrobenzene, and diethyl carbonate. LiPF ₆ Specifically illustrating a preferred lithium salt as an electrolyte, LiSbF _6, LiAsF _6, LiB
F ₄ , LiClO ₄ , LiCF ₃ CO ₃ , LiI, LiAl
Examples thereof include Cl _{4 and the} like, but the present invention is not limited thereto. These lithium salts may be used alone or in combination of two or more.

When an electrolytic solution is used in the secondary battery of the present invention,
Careful attention is required to prevent liquid leakage. Further, it is desirable that the separator be used by preliminarily containing an electrolytic solution. In order to avoid these complications, it is preferable to use a solid electrolyte in the present invention, and the use of a solid electrolyte is also advantageous in that the distance between the positive and negative electrodes is kept constant. The solid electrolyte suitable for the secondary battery of the present invention is specifically shown as LiI
_{-Li 2 S (37wt%) -} P 2 S 5 (18wt%) inorganic compound complex such as; LiI polyethylene oxide, polypropylene oxide, polyvinylidene fluoride, a polymer matrix such as polyacrylamide, Li
A complex in which a lithium salt such as BF ₄ , CF ₃ SO ₃ Li, etc. is dissolved; or a gel cross-linked product thereof, etc., but is not limited thereto. The solid electrolyte may be used alone, but it is preferable to use it in combination with the separator from the viewpoint of making the current density uniform and preventing short circuit.

In the secondary battery of the present invention, nickel, titanium, copper, stainless steel, aluminum or the like is used as a metal film current collector, and the current collector film is used as a substrate on which electrodes are formed in a film shape. In particular, aluminum is suitable as a material for the current collector film because it is inexpensive, lightweight, and has high malleability and conductivity. The partition wall (frame) used in the battery of the present invention is preferably an insulator that is not reactive with the battery element and can be bonded to the current collector or the exterior. Specifically, it is preferable to use a resin layer made of polyethylene, polypropylene, nylon, polyester or the like and an adhesive layer. The adhesive layer may be made of a heat-fusible resin such as modified polyethylene or modified polypropylene, or an epoxy resin or an acrylic resin. An adhesive such as a system is used. In particular, when polyethylene or polypropylene is used for the resin layer and modified polyethylene or modified polypropylene is used for the adhesive layer, it is optimal in terms of adhesion to the current collector, stability, and the like.

Specific embodiments of the present invention will be described below. However, the following specific embodiments are examples of the embodiments of the present invention, and the present invention is not limited to these embodiments. 1. A battery electrode having at least one kind of active material (1), wherein the active material (1) contains a plasticizer. 2. In the above secondary battery electrode, the active material (1)
An electrode for a secondary battery in which is polyaniline. 3. The secondary battery electrode according to 1 or 2 above, wherein at least one kind of particulate active material (2) is homogeneously dispersed in a matrix of the active material (1). 4. In the secondary battery electrode according to the above 3, the active material (2)
Is 70 to 95% of the total weight of the electrode. 5. In the secondary battery electrode according to 4 above, the active material (2)
Is a fine particle having an average particle size of 10 μm or less, preferably 3 μm or less, and a maximum particle size of 30 μm or less, preferably 10 μm or less. 6. In the secondary battery electrode of 3, 4, or 5,
An electrode for a secondary battery, wherein the active material (2) is an oxide of a transition metal such as V, Co, Mn, or Ni, or a composite oxide of the above transition metal and an alkali metal. 7. In the secondary battery electrode according to the above 6, the active material (2)
Is a vanadium pentoxide electrode for a secondary battery. 8. In the secondary battery electrode of 3, 4, 5, 6 or 7, the active material (1) and (2) are combined in a solvent in which the active material (1) is dissolved or at least partially dissolved. A certain secondary battery electrode. 9. In the secondary battery electrode of 1, 2, 3, 4, 5, 6, 7 or 8, the plasticizer can plasticize the polymer material, and is less likely to be easily redox-reduced by the electrode reaction. Which is an electrode for a secondary battery. 10. The secondary battery electrode according to 9 above, wherein the plasticizer is an organic solvent having a boiling point of 200 ° C. or higher and a vapor pressure of 5 mmHg (85 ° C.) or lower. 11. In the secondary battery electrode of 9 or 10, diphtyl phthalate (DBP), di-n-octyl phthalate (DnOP), di (2-ethylhexyl) phthalate (D
OP), di (2-ethylhexyl) adipate (DO
A), di (2-ethylhexyl) sebacate (DOS)
And an electrode for a secondary battery, which is at least one plasticizer selected from the group consisting of dibutyl sebacate. 12. 3, 4, 5, 6, 7, 8, 9, 10 or 1
The secondary battery electrode according to item 1, wherein the plasticizer content is 0.1 to 5% by weight relative to the active material (1). 13. 1, 2, 3, 4, 5, 6, 7, 8, 9, 1
A secondary battery using a 0, 11 or 12 secondary battery electrode as a positive electrode.

[0020]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 A polyaniline powder prepared by a chemical polymerization method was dissolved in N-methylpyrrolidone to prepare a solution containing 13% by weight of polyaniline. V liquid of fine powder having an average particle size of 5 μm was added to this liquid.
₂ O ₅ fine powder was converted to polyaniline: V ₂ O ₅ = 3: 7 (weight ratio)
Was added. DBP was added to the dispersion so as to be 1% by weight of polyaniline solid content to prepare a homogeneous dispersion a for forming a positive electrode. On the other hand, outer diameter 140 × 140 mm,
140 x 140 outer diameter on aluminum foil 1 with a thickness of 30 μm
A polypropylene partition wall 2 having a diameter of 130 mm, an inner diameter of 130 × 130 mm, and a thickness of 350 μm was adhered by a heat fusion method. Then, the positive electrode forming dispersion liquid a was uniformly applied onto the aluminum foil 1 partitioned by the partition walls 2 so that the thickness was 100 μm, and then dried at 100 ° C. for 30 minutes to produce the positive electrode member 3. . The procedure for producing the positive electrode member is shown in FIG.

Next, 3 mol of L was added to 1 liter of a mixed solution of propylene carbonate and dimethoxyethane having a volume ratio of 7: 3.
A polymer solid electrolyte forming liquid b was prepared which was composed of 80% by weight of a solution in which iBF ₄ was dissolved, 19.2% by weight of ethoxydiethylene glycol acrylate and 0.8% by weight of benzoin isopropyl ether. A 25 μm thick polypropylene pore filter (trade name: Celgard)
And was laminated on the positive electrode member 3 and then irradiated with ultraviolet light of a high pressure mercury lamp to obtain a positive electrode member 4 on which a gelled solid electrolyte was laminated. On the other hand, a metallic lithium negative electrode 6 having an outer diameter of 130 × 130 mm and a thickness of 100 μm was attached onto a copper plate current collector 5 having an outer diameter of 140 × 140 mm and a thickness of 30 μm with a commercially available conductive adhesive, The polymer solid electrolyte-forming liquid b was applied on top, and then irradiated with ultraviolet light from a high-pressure mercury lamp to obtain a negative electrode member 7 in which a polymer solid electrolyte was laminated on metallic lithium. The member is a member in which a negative electrode 6 is laminated on a current collector 5 and a polymer solid electrolyte is laminated thereon.

Next, as shown in FIG. 2, the member 4 and the member 7 are pressure-bonded to each other and the solid polymer electrolytes are adhered to each other, and the partition wall 2 is heat-sealed with the current collector 5 to be sealed, and the outer diameter is obtained. 140 mm x 140
A thin sheet-shaped battery having a thickness of 0.4 mm and a thickness of about 0.4 mm was produced. The battery was charged to a capacity where the output voltage was 4.2 V, and then discharged to a capacity where the output voltage was 2.5 V at a current value of 50 mA. The results of various battery evaluations performed by repeating the above evaluation test are shown in Table 1. The initial capacity shown in Table 1 is the data of the 5th cycle. In addition to the above, Table 1 shows the results of a battery bending (5 times) test.

Example 2 A thin sheet battery having a thickness of about 0.4 mm was prepared in the same manner as in Example 1 except that DOA was used instead of DBP.
The results of the evaluation test of the battery are shown in Table 1.

Example 3 A thin sheet battery having a thickness of about 0.4 mm was produced in the same manner as in Example 1 except that dibutyl sebacate was used instead of DBP. The results of the evaluation test of the battery are shown in Table 1.

Comparative Example 1 A thin sheet battery having a thickness of about 0.4 mm was produced in the same manner as in Example 1 except that the positive electrode was applied and dried without adding DBP. Table 2 shows the results of the evaluation test of the battery.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

【effect】

1. Regarding the inventions of claims 1, 3, 4, 5 and 6, a plasticizer capable of plasticizing the active material (1) to the active material (1), particularly one which is not easily susceptible to redox due to electrode reaction, or boiling point 200 ℃ or more, vapor pressure 5mmHg
By blending a plasticizer as an organic solvent having a temperature of (85 ° C.) or less, a flexible secondary battery electrode having high adhesion to a substrate could be obtained. 2. According to the invention of claim 2, by homogenously dispersing the particulate active material (2) in the active material (1), a secondary battery electrode having a high energy density and excellent cycle characteristics could be obtained. 3. With respect to the invention of claim 7, a secondary battery having high strength, flexibility, and high energy density can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a procedure for producing a positive electrode member.

FIG. 2 is an explanatory diagram showing a procedure for producing a thin battery using the positive electrode member shown in FIG.

[Explanation of symbols]

 a dispersion liquid for forming a positive electrode b solid polymer electrolyte forming liquid 1 aluminum foil 2 partition wall 3 positive electrode member 4 positive electrode member 5 having a solid electrolyte laminated 5 current collector 6 negative electrode 7 negative electrode member having a solid electrolyte laminated

Front page continued (72) Inventor Toshiyuki Kabata 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (7)

[Claims] 1. A battery electrode having at least one kind of polymer material which shows an electrochemical redox reaction,
An electrode for a secondary battery, wherein the polymer material contains a plasticizer. 2. The electrode for a secondary battery according to claim 1, wherein at least one kind of particulate inorganic active material is homogeneously dispersed in a matrix of a polymer material. 3. The secondary battery electrode according to claim 1, wherein the plasticizer can plasticize the polymer material,
In addition, an electrode for a secondary battery, which is resistant to redox due to an electrode reaction. 4. The secondary battery electrode according to claim 3, wherein the plasticizer has a boiling point of 200 ° C. or higher and a vapor pressure of 5 mmHg (8
An electrode for a secondary battery, which is an organic solvent having a temperature of 5 ° C. or less. 5. The secondary battery electrode according to claim 3 or 4, wherein dibutyl phthalate (DBP) or di-phthalate is used.
n-octyl (DnOP), di (2-ethylhexyl) phthalate (DOP), di (2-ethylhexyl) adipate (DOA), di (2-ethylhexyl) sebacate
An electrode for a secondary battery, comprising at least one plasticizer selected from the group consisting of (DOS) and dibutyl sebacate. 6. The secondary battery electrode according to claim 1, 2, 3, 4, or 5, wherein the content of the plasticizer is the active material (1).
0.1 to 5% by weight of the electrode for secondary battery. 7. A secondary battery using the electrode for secondary battery according to claim 1, 2, 3, 4, 5 or 6 as a positive electrode.