JP2001243984A - Solid electrolyte battery and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the problem in a solid electrolyte that the internal resistance is high and the charge and discharge current and charge and discharge capacity are small. SOLUTION: The solid electrolyte battery comprises one polarity electrode made of a porous structure of active material and particle bound material, a solid electrolyte layer made of ion conductive material that has been adhered to the gap portion surface of this porous structure, and the other polarity electrode made of the other active material and a filling that have been filled in the gap portion of this porous structure. A current collector is provided to the above one polarity electrode and the other polarity electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolyte battery and a method of manufacturing the same, and more particularly, to a solid electrolyte battery having improved charge / discharge current and charge / discharge capacity by reducing the internal resistance of an electrode, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, devices utilizing an electrochemical reaction of electrodes include those of the liquid type and the gel type. For example, in a non-aqueous electrolyte lithium ion battery, a positive electrode in which a positive electrode active material is applied to a positive electrode current collector, and a negative electrode in which a negative electrode active material is applied to a negative electrode current collector are laminated with a separator interposed therebetween. Impregnation with an electrolyte with high ion conductivity composed of an organic solvent and a lithium salt causes good ion migration at the interface between the electrode and the electrolyte, and oxidation and oxidation at the interface between the active material of the positive and negative electrodes and the electrolyte. Good transfer of electrons and ions is caused along with the reduction reaction, and battery characteristics at a practical use level are obtained.
This is made possible by the good wettability of the liquid electrolyte and the high ionic conductivity, and the properties of the practical use level are obtained for the gel electrolyte for almost the same reason. There are the following examples as attempts to further improve a liquid or gel electrolyte battery.

According to Japanese Patent Application Laid-Open No. Hei 10-223207, in a non-aqueous electrolyte secondary battery similar to the above, unevenness is formed on at least one of a positive electrode and a negative electrode to increase the surface area of the battery. According to the company, the current capacity has been increased and the current load characteristics of the battery have been improved, so that even if the battery is overcharged or discharged with an excessive current, there is no danger of performance degradation. According to this publication, as a conventional example of improving the load characteristics, along with the adoption of a low-viscosity solvent system, the surface area that contributes to the electrochemical reaction by reducing the thickness of the electrode and increasing the length at the same time as reducing the thickness of the electrode In this example, the load characteristics of the secondary battery are improved by increasing the load. However, as the length of the electrode increases, the proportion of the volume occupied by the current collector that does not contribute to the electrochemical reaction also increases, and the battery capacity per unit volume decreases.

According to Japanese Patent Application Laid-Open No. H11-162519, in a conventional lithium ion secondary battery, since the reaction surfaces of a pellet-shaped positive electrode and a negative electrode are limited to a portion in contact with a separator, the entire active material is not used. This does not contribute to the reaction, the theoretical capacity required from the weight of the positive electrode active material cannot be obtained, and the contact area between the positive electrode, the negative electrode and the separator is not sufficient, and the internal resistance of the battery increases. Was. Therefore, by forming irregularities on the surfaces of the positive electrode and the negative electrode and arranging the positive electrode and the negative electrode via a separator so that the irregularities mesh with each other, the contact area is increased to reduce the internal resistance and improve the capacity. It is said that it was possible. On the other hand, demands for safety, miniaturization, a wide operating temperature range, or ease of use have increased in recent years,
The study of all solid-state devices has been studied, and a conventional example of a solid electrolyte has been given.

According to Japanese Patent Application Laid-Open No. 5-109429 (5), in a laminate having an electron conductor layer and an ion conductor layer made of an inorganic oxide, the interface between the two layers is brought into irregular contact to form a laminate. It is said that the reaction efficiency is improved by increasing the surface area of the interface, and the movement of electrons and ions in the electrode reaction is improved.

According to Japanese Patent Application Laid-Open No. Hei 9-180705, a positive electrode of a lithium battery having a solid electrode in which an active material or a mixed powder of an active material and a conductive agent is in direct contact with a polymer solid electrolyte or a gel electrolyte is disclosed. In the negative electrode, the contact between the active material particles and the solid polymer electrolyte or gel electrolyte was poor, and the impedance at the interface was high.Therefore, a layer of polyvinylpyridine and an electrolyte with good wettability was formed on the surface of the active material particles. By filling the voids of the particles with an electrolyte, the adhesion between the active material particles is improved, the capacity of the battery is improved, and a stable cycle property is obtained.

[0007]

SUMMARY OF THE INVENTION The present invention improves the problems of the conventional liquid system and the conventional solid system more effectively, and at the same time, the physical properties of the electrode matrix and the electrolyte are low in ionic conductivity. It is an object of the present invention to propose a structure that compensates for a solid electrolyte.

In the conventional examples 1 to 3, the sheet-shaped electrode and the electrolyte are laminated, and their cross sections are made rectangular by maintaining the interface between the electrodes 2 and 4 and the electrolyte 3 while maintaining a rectangular shape as shown in FIG. It is intended to increase the contact area, and it is thought that there is an effect of reducing the interface resistance in proportion to the increase in the contact area, but there is a limit to the improvement. Object 1 of the present invention is to overcome this limit.

In the conventional example shown in FIG. 3, the positive electrode 2, the negative electrode 4, and the solid electrolyte 3 each have a rectangular (sheet-like or pellet-like) cross-sectional shape. Laminated to form a solid electrolyte battery. In FIG. 3, each of the electrode 2 and the electrode 4 is made of either a positive electrode active material powder or a negative electrode active material powder, and a binder made of an electron conductivity-imparting substance and a solid electrolyte. According to FIG. 3, the contact area of the interface between the electrodes 2, 4 and the solid electrolyte 3 is proportional to the distance GH. In the above-mentioned conventional examples, the boundary between the electrodes 2, 4 and the solid electrolyte 3 is formed into a wavy line or a sawtooth shape by surface processing or the like at the time of sheet forming, and there is an effect of reducing the interface resistance in proportion to the increase of the line segment.

Further, according to FIG. 3, when ions or electrons move between layers, there is a difference in movement resistance due to a difference in movement distance. Between the positive electrode active material and the negative electrode active material, that is, A-
When compared between B and CD, the distance that the ions move between them is (between AB) <(between CD) and the migration resistance during this period is (between AB) <( CD-D), and there is an internal resistance proportional to the distance between any positive electrode active material and negative electrode active material. The layer thickness in FIG. 3 is generally around 100 μm for the electrode and around 10 μm for the electrolyte. Therefore, the moving distance is 10
μm to 200 μm, and the average travel distance is 100
It is around μm.

In addition, there is resistance due to the difference in carriers between ions and electrons. In addition, there is resistance due to the difference in electrolyte between the liquid system and the solid system. Ions are larger in size and mass than electrons and are generally difficult to move at high speed in solids, but can easily move at high speed in non-aqueous electrolytes.

A non-aqueous electrolyte comprising an organic solvent containing a lithium salt has an ion conductivity of 1 × 10 ^-2 to 10 ^-3 Ω ^-1 cm ^-1.
The resistance difference due to the difference in the moving distance is extremely small and can be ignored. On the other hand, in the solid electrolyte 3, the ionic conductivity is generally as small as 1 × 10 ⁻⁴ to 10 ⁻⁶ Ω ⁻¹ cm ^−1, and the resistance due to such a moving distance is large, and the resistance difference due to the difference in the moving distance is extremely large. On the other hand, electrons also have a C-
Although E and DF are different from AE and BF, the original moving speed of electrons is faster than the moving speed of ions, the resistance due to this moving distance is small, and the resistance difference due to the difference in moving distance is small. .

However, if the amount of the electron-conductivity-imparting material is reduced in order to increase the amount of the active material in the electrodes 2 and 4, for example, the electron-conductivity-imparting material becomes insufficient and the Disturbance occurs in the structure, the electron conductivity decreases, the resistance according to the moving distance of the electrons increases, and the resistance difference due to the difference in the moving distance increases, and cannot be ignored.

In the prior art, the contact interface (so-called grain boundary) resistance between the electrode active material powder and the matrix-like solid electrolyte surrounding the electrode active material powder is reduced. The present invention gives another example of reducing the grain boundary resistance.

There is an important problem which does not exist in the prior art.
That is, the bulk resistance of the electrode matrix surrounding the electrode active material powder composed of the solid electrolyte and the solid electrolyte layer is large. This is because the solid electrolyte has a lower ionic conductivity than liquid or gel electrolytes. For this reason, an internal resistance proportional to the movement distance of the ions from the positive electrode active material powder to the negative electrode active material powder appears, and due to this resistance, the charge / discharge current density decreases or the positive electrode and the negative electrode However, there has been a problem in that the reaction surface is limited to the region in contact with the solid electrolyte, the utilization factor of the active material decreases, and the charge / discharge capacity decreases. An object 2 of the present invention is to solve this problem.

In the first object, since the movement of ions also occurs at the interface between the electrode and the electrolyte layer, the surface area of this interface may be made as large as possible in comparison with the conventional example. In the purpose 2, since the chemical reaction (oxidation-reduction reaction), which is a characteristic of the electrochemical element, occurs at the interface between the active material powder and the electrolyte surrounding the active material powder, the surface area of the grain boundary should be increased as much as possible to increase the reaction efficiency. What is necessary is just to make the movement distance of the ions from the positive electrode active material powder to the negative electrode active material powder as short as possible.

The present invention proposes a new structure of an ionics element in which an electrolyte utilizing an electrochemical reaction of an electrode is a solid, more specifically, a new structure of a solid electrolyte battery. It is to reduce the transfer resistance of ions from the positive electrode active material powder to the negative electrode active material powder caused by the interface resistance of the electrolyte layer and the bulk resistance of the electrolyte. In addition, the transfer resistance of electrons from the positive electrode (or negative electrode) active material powder to the positive electrode (or negative electrode) current collector is also reduced. The ultimate object of the present invention is to reduce these internal resistances,
It is to improve the charge / discharge current and charge / discharge capacity of a solid electrolyte battery.

[0018]

According to a first aspect of the present invention, there is provided a solid electrolyte battery comprising: a monopolar electrode comprising a porous structure of an active material and a particle binding material; and a surface of a void portion of the porous structure. A solid electrolyte layer made of an adhered ion conductive material, and another polar electrode made of another active material and a filling material filled in a void portion of the porous structure; A current collector was provided on the electrode and the other polarity side electrode.

In the above solid electrolyte battery, it is preferable that an electron conductivity imparting substance is added to the active material of the porous structure.

In the above-mentioned solid electrolyte battery, it is preferable that the particle binder is composed of the ion-conductive substance and / or the dielectric substance.

In the above-mentioned solid electrolyte battery, it is desirable that the ion-conductive substance is made of one or more of crystallized glass, low-melting glass, and polymer.

In the above-mentioned solid electrolyte battery, it is desirable that the above-mentioned particle binder is added to the above-mentioned solid electrolyte layer.

In the above-mentioned solid electrolyte battery, it is preferable that the electron conductivity-imparting material is added to the other active material of the other polar electrode.

In the above solid electrolyte battery, it is preferable that the filling material is made of an ion conductive material and / or a dielectric material.

In the method of manufacturing a solid electrolyte battery according to the eleventh aspect, the formed form of the active material powder containing the particle binder and the organic binder is fired to form a porous structure, The solid electrolyte powder containing the agent is made viscous with a solvent, impregnated into the porous structure, fired, and a solid electrolyte layer is adhered to the surface of the void portion of the porous structure, further containing a filling material. The other active material powder to be converted into a viscous liquid with a solvent is filled in the voids of the porous structure and fired.

[0026]

FIG. 1 is a schematic view showing a cross section of a solid electrolyte battery according to the present invention. FIG. 2 is an enlarged view of a main part of the cross section of FIG.

1 and 2, reference numeral 1 denotes a collector on one polarity side (positive or negative electrode), 2 denotes an electrode on one polarity side (positive or negative), 3 denotes a solid electrolyte layer, and 4 denotes a collector on the other polarity side (negative or negative). Or positive) electrode, 5 is the other polarity side (negative electrode or positive electrode)
It is a current collector. Hereinafter, for convenience, one polarity side will be described as positive and the other polarity side will be described as negative. The difference between FIGS. 1 and 2 and FIG. 3 is the cross-sectional shape of the positive electrode, the negative electrode, and the solid electrolyte.

In FIG. 1, the cross-sectional shape of the positive electrode 2 having a porous structure as a skeleton is schematically shown as a grape cluster of large particles, and the cross-sectional shape of the negative electrode 4 is small particles. The cross-sectional shape of the solid electrolyte 3 has a constant thin thickness at the boundary between the cross section of the positive electrode 2 and the cross section of the negative electrode 4. 2 is a thin layer schematically shown in FIG. 2, which is an enlarged view of a main part of FIG.

The grape cluster-shaped positive electrode 2 is in a conductive state in electron conductivity and ion conductivity. It is electronically connected to the current collector 1. In addition, FIG. 1 shows an isolated grape cluster-shaped cross-section 6, which is connected to the grape cluster-shaped positive electrode 2 at other cuts, and each is a part of the porous material electrode.

In FIG. 1, the positive electrode 2 is composed of a positive electrode active material powder and a particle binder, and may further contain an electron conductive material. Further, the solid electrolyte 3 has ion conductivity and is made of a particle binding material or the like. Further, the negative electrode 4 is composed of a negative electrode active material powder and a filling material, and may further contain an electron conductive material. Current collectors 1, 5 of FIG.
The thickness excluding is set to about 200 μm in order to retain an active material substantially equivalent to that in FIG.

Based on FIG. 1, the movement distance between the positive electrode 2 and the negative electrode 4 for each of ions and electrons is considered as follows.
At any point of the electrodes 2 and 4, it is about the size of a grape cluster-shaped powder particle of the positive electrode 2 which is a porous structure, or the powder of the negative electrode 4 filled so as to fill the porous body. It is clear from the figure that the size is about the size of a grain, that is, several μm at most.

With such a small moving distance, the ionic resistance and the electronic resistance due to the moving distance are very small even if the ion conductivity and the electron conductivity in the electrodes 2 and 4 are small. Further, the thickness of the solid electrolyte 3 is small, and the ionic resistance in the solid electrolyte 3 is also small. Further, with respect to the electron conductivity accompanying the moving distance between the electrodes 2 and 4 and the current collectors 1 and 5, the electronic resistance is small and negligible if high electron conductivity is secured in the electrodes 2 and 4. That is, even if the resistivity of ions and electrons is two orders of magnitude higher than that of a liquid system, the moving distance can be reduced by about two orders of magnitude according to the present invention. it can. Also, the area of the interface between the electrodes 2 and 4 and the solid electrolyte 3 increases dramatically as can be easily inferred from FIG. Therefore,
The resistance at the interface between the electrodes 2, 4 and the solid electrolyte 3 can also be drastically reduced.

As described above, the electrodes 2, 4 and the solid electrolyte 3 have a thin layer thickness, and are uniform on the layer surface having a wide charge / discharge current density. The discharge current density (this density is per unit area with respect to the current collectors 1 and 5) increases, and the charge / discharge capacity also increases.

There are various methods for forming a solid electrolyte battery having a structure as shown in FIGS.

First, an electrode 2 having a porous structure made of a positive electrode active material is prepared. The powder of the positive electrode active material is bound with a particle binding material to produce a porous body serving as a skeleton of a solid electrolyte battery. The filling rate of the porous body is preferably 50% or less from the utilization rate of the charge / discharge action, but is not limited thereto.

As the particle binding substance, an ion conductive substance, a lithium-containing substance, a dielectric substance, and the like are preferable. For example, crystallized glass, amorphous glass, an organic polymer, or the like having ion conductivity, or lithium is contained. Examples thereof include a low melting point glass having a composition, an oxide of a metal alkoxide by a sol-gel method, and the like, and these can be used alone or in combination. For example, ion-conductive crystallized glass has a high melting point, and if the temperature of the active material powder rises at a high binding temperature, the crystal structure of the active material may be destroyed and hinder the oxidation-reduction reaction. Specifically, it is preferable to mix and use a low-melting glass or the like that can bind at a low temperature as the particle binder.

When the active material particles are bound with a particle binder to form a porous material, and the electron conductivity of the porous material is small and insufficient, the active material particles may be provided with an electron conductivity imparting material. When the particles are used in a mixed state, the electron conductivity can be increased and the electron transfer resistance can be reduced.

This porous structure is formed into a viscous liquid (slurry) together with a solvent, an organic binder, and the like, by powdering the active material powder and the particle binder material powder, forming the sheet with a doctor blade, drying, and sintering. Can be created. The organic binder or the like used for molding can be fired and blown off to form voids in the porous structure. In addition to the doctor blade method, there are a printing method and a dipping method. In addition, this porous structure
It can be prepared by mixing an active material powder or the like with a metal alkoxide to make a liquid (slurry), forming a sheet or the like, and drying. During drying, the alcohol component is vaporized, and voids in the porous structure can be created.

More specifically, as a particle binder, P
VdF (polyvinylidene fluoride), PEO (polyethylene oxide), lithium hydroxide, lithium carbonate, lithium phosphate, _{also, Li 2 O-SiO 2,} Li 2 O-SiO 2 -
Lithium-containing metal oxide such as P ₂ O ₅ (metal one or _{more), Li x P y O 1} -z N z lithium-containing metal nitride such as, TiS _2, or Li ₂ S-SiS ₂ -LiI etc. And lithium-containing transition metal oxides such as lithium titanium oxide. These may be used alone or in combination.

As the material of the positive electrode active material, for example, lithium
Cobalt oxide, lithium nickel oxide, lithium
Manganese oxide, lithium nickel manganese oxide,
Titanium oxide, lithium iron manganese oxide,
Or lithium-containing transitions such as lithium vanadium oxide
Metal oxides (one or more transition metals) and man dioxide
Gun, niobium pentoxide, lithium transition metal composite nitride, T
iS_TwoOr V_TwoO _Five-P_TwoO_FiveAnd the like.

Further, as the electron conductivity imparting substance, a car
And metal oxides such as acetylene black, ITO, and SnO ₂ . Here, the case where the electrode of the porous structure is the positive electrode 2 is described, but when the electrode is the negative electrode 4, it may be replaced with a negative electrode active material described later.

Next, the positive electrode current collector 1 is formed on one surface of the positive electrode 2. There are various methods for the formation. For example, an electron conductive film (Au, Ag, Al, Cu, or the like) is formed on at least one surface of the electrode 2 of the porous structure by a vapor deposition method or a sputtering method, or a conductive paste (Au or Ag) is formed.
Or a mixture of Al and Cu particles mixed with a resin) and sintering. As another forming method, a sheet-shaped metal foil made of nickel, stainless steel, aluminum, copper, carbon, or the like may be attached to an electrode with a resin paste containing a mixture of electron conductive particles, and then dried and fired.

Next, the surface of the void portion of the obtained porous structure is covered with an electrolyte to form a thin solid electrolyte layer 3 as shown in FIG. In order to form such a solid electrolyte layer 3, a material having ion conductivity such as the above-mentioned particle binding material is suitable. Impregnated into the porous structure and dried. Further, the coating is formed by impregnating the porous structure with a solution capable of forming an oxide of a metal alkoxide or the like by a sol-gel method without using the above-mentioned particle binder, hydrolyzing and heating. .

Next, the negative electrode active material is filled into the voids of the porous structure on which the solid electrolyte 3 is adhered to form the electrode 4.
The powder of the negative electrode active material is impregnated into the voids of the electrode 2 together with the filling material to prepare a filling body that will be the other electrode of the solid electrolyte battery. Due to the filling of the packing, these structures have a packing ratio of 1
It is preferable to be able to be formed to be close to 00% from the viewpoint of the volume energy density of the charge / discharge action, but it is not limited to this.

As the filling material of the negative electrode, an ion conductive material, a lithium-containing material, a dielectric material, or the like is preferable.
Specifically, crystallized glass having ion conductivity, amorphous glass, organic polymer, gel electrolyte, non-aqueous electrolyte, or the like, or low melting glass having a lithium-containing composition, or metal alkoxide by the sol-gel method Such as oxides or dielectric materials such as organic solvents,
These can be used alone or in combination. For example, ion-conductive crystallized glass has a high melting point, and if the temperature of the active material powder rises at a high binding temperature, the crystalline structure of the active material may be destroyed, which may hinder the oxidation-reduction reaction. More specifically, it is preferable to use a mixture of an organic polymer capable of binding at a low temperature as a filling substance.

When the active material particles are bound with a filler material to form a filler, if the electron conductivity of the filler material is small and insufficient, the active material particles are mixed with electron conductivity imparting material particles. If used, the electron conductivity can be improved and the electron transfer resistance can be reduced.

The filling structure can be prepared by making the active material powder and the filling material into a liquid (slurry) together with a solvent and the like, impregnating the porous body, drying and firing. The size of the impregnated particles forming the electrode 4 is preferably smaller from the viewpoint of increasing the impregnation amount (filling rate) than the size of the skeletal particles forming the electrode 2. In addition, a filling material that can be formed at a lower temperature and does not generate a vaporized material during firing can increase the filling rate.

As the material of the negative electrode active material, for example, metal materials such as lithium metal, lithium alloy, graphite and coke, lithium titanium oxide, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium manganese oxide, lithium A transition metal oxide containing lithium such as nickel manganese oxide, lithium iron manganese oxide or lithium vanadium oxide (at least one type of transition metal), manganese dioxide, niobium pentoxide, lithium transition metal composite nitride, or TiS ₂ And the like.

Examples of the electron conductivity-imparting material used together with the negative electrode active material include carbon, acetylene black, metal oxides such as ITO and SnO. Here, the case where the electrode of the filling structure is a negative electrode is described,
In the case of a positive electrode, the negative electrode active material may be replaced with the above-described positive electrode active material.

Next, a negative electrode (or positive electrode) current collector 5 is formed on the current collector 1 on the side facing the battery cell. As a formation method,
Various methods are conceivable, and are not limited to the following forming methods. For example, an electron conductive film or the like is formed on the filling electrode 4 by a vapor deposition method, a sputtering method, or application and firing of a conductive paste.

In FIG. 2, an intermediate layer may be provided between the electrode 2 and the solid electrolyte 3 and between the electrode 4 and the solid electrolyte 3, and such an intermediate layer is preferably formed spontaneously by a reaction at a process temperature. The composition is generally an intermediate composition.

In FIG. 2, the electrode 2, the solid electrolyte 3, and all the constituent layers of the electrode 4 are impregnated with an organic solvent or an organic solvent and a non-aqueous electrolyte such as a lithium salt. In addition, a small void (defect) included in the electrode 2 can be filled, and a better current density result can be obtained. Examples of the organic solvent include PC (propylene carbonate) and NMP (N-methyl-2-pyrrolidone). The lithium salt to be impregnated is L
iBF _4, and the like.

By stacking a plurality of power generation cells of the present invention, it is possible to increase the generated voltage or the generated current.

Although FIG. 1 does not show the positive / negative electrode terminals, the protective film, or the outer package of the solid electrolyte battery, these electrode terminals may be metal leads connected to the current collectors 1, 5, and the like. The protective film or the exterior may be formed so as to cover the outer peripheral surface of the solid electrolyte battery so as not to cover the metal leads. As a result, intrusion of moisture into the solid electrolyte battery can be suppressed. Examples of the protective film include a sealing material for moisture resistance and / or airtightness, such as a protective resin for a semiconductor chip and inorganic glass. As the protective exterior body, a laminated film in which a metal sheet is laminated with insulating polyethylene terephthalate (PET) or polyethylene (PE) or the like can be used in order to impart electrical insulation and decorative properties to the outer surface.

[0055]

EXAMPLE A solid electrolyte battery having a plane size of 20 mm × 20 mm and a sectional shape as shown in FIG. 1 was produced.

Low-melting glass (Li ₂ O—) having lithium ion conductivity as a particle binder is 85% by weight of lithium titanium oxide (Li [Li _1/3 Ti _5/3 ] O ₄ ) as a negative electrode active material. B ₂ O ₃ -ZnO) were mixed 15% by weight. A binder (polyvinyl butyral) was added to this mixture, and the paste was adjusted using toluene as a solvent. The adjusted paste was formed into a sheet with a doctor blade so as to have a thickness of 200 μm. After drying, it was sintered at 650 ° C. to form a porous electrode.

On one side of this porous electrode, A
u was deposited to a thickness of 0.5 μm to form a negative electrode current collector.

Next, a low-melting glass (Li ₂ O—B ₂ O ₃ —Zn) having lithium ion conductivity as a solid electrolyte
The fine powder of O) was adjusted in viscosity with toluene to form a solution. The prepared solution was impregnated into a porous electrode, dried, and fired at 500 ° C. Shortening was prevented by reducing the solution viscosity and repeating the film formation several times.

Next, lithium manganese was used as the positive electrode active material.
Oxide (Li [Li_0.1Mn_1.9] O _Four) At 80% by weight
Acetylene butane as an additive to impart electronic conductivity
10% by weight of rack and PVd as particle binder
F (polyvinylidene fluoride) was mixed at 10% by weight. this
NMP (N-methyl-2-pyrrolide) was added to the mixture.
Was added and mixed to prepare a positive electrode forming paste. Key
The prepared solution is impregnated into the porous material electrode, dried and filled
Electrodes were made.

Next, A was deposited on the surface of the filled electrode with a vapor deposition device.
u was deposited to a thickness of 0.5 μm to form a positive electrode current collector.

The discharge current density of this cell was 11 μA / cm ² . The charge / discharge utilization rate was 20%. [Comparative] Next, for comparison, the plane size was 20 mm.
A solid electrolyte battery having a size of × 20 mm and a cross section as shown in FIG. 3 was produced.

Low-melting glass (Li ₂ O—) having lithium ion conductivity as a particle binder is 85% by weight of lithium titanium oxide (Li [Li _1/3 Ti _5/3 ] O ₄ ) as a negative electrode active material. B ₂ O ₃ -ZnO) were mixed 15% by weight. A binder (polyvinyl butyral) was added to this mixture, and the paste was adjusted using toluene as a solvent. The adjusted paste was formed into a sheet by a doctor blade. After drying, this was sintered at 700 ° C. to form a more dense negative electrode 2 having a thickness of 90 μm.

Next, as the solid electrolyte 3, lithium ion conductive crystallized glass (Li ₂ O—SiO _{2 ,} Li ₂ O—
A powder of SiO ₂ —P ₂ O ₅ ) and a powder of low melting point glass (Li ₂ O—B ₂ O ₃ —ZnO) having lithium ion conductivity were adjusted with toluene to obtain a paste. After printing the prepared paste on the negative electrode and drying it, 550
The solid electrolyte 3 having a thickness of 20 μm was obtained by firing at ℃.

Next, lithium manganese was used as the positive electrode active material.
Oxide (Li [Li_0.1Mn_1.9] O _Four) At 80% by weight
Acetylene butane as an additive to impart electronic conductivity
11% by weight of rack and PVdF as filling material
(Polyvinylidene fluoride) at 9% by weight,
Add NMP (N-methyl-2-pyrrolidone) to the mixture
The paste for forming the positive electrode was adjusted in total. Adjusted pace
After printing on the laminate and drying, baking at 500 ° C
As a result, a positive electrode having a thickness of 90 μm was formed.

Next, on both surfaces of the negative electrode and the positive electrode, Au was vapor-deposited to a thickness of 0.5 μm by a vapor deposition device to form a negative electrode and a positive electrode current collector.

When the discharge current density of this cell was determined, it was 1 μA / cm ² . The charge / discharge utilization rate was 2%.

[0067] For comparative example of the conventional structure, the product of the present invention the discharge current density is increased from 1 .mu.A / cm ² to 11μA / cm ^2, and improved utilization of the charging and discharging from 2% to 20% along with this .

[0068]

As described above, according to the solid electrolyte battery according to the first aspect, the unipolar electrode composed of the porous structure of the active material and the ion adhered to the void surface of the porous structure are provided. Since it has a solid electrolyte layer made of a conductive material and another polar side electrode made of another active material filled in the voids of the porous structure, the high internal resistance of the solid electrolyte is significantly reduced, and the solid electrolyte is filled. Discharge current and charge / discharge capacity can be improved.

Further, according to the method for manufacturing a solid electrolyte battery according to the eleventh aspect, a porous structure is formed by firing a formed form of active material powder containing a particle binder and an organic binder. The solid electrolyte powder containing the binder is made viscous with a solvent, impregnated into the porous structure, fired, and the solid electrolyte layer is adhered to the surface of the void portion of the porous structure,
Furthermore, since the other active material powder containing the filling material is made into a viscous state together with a solvent and filled into the voids of the porous structure and fired, the high internal resistance of the solid electrolyte is significantly reduced, and the charge / discharge current and A solid electrolyte battery with improved charge / discharge capacity can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a solid electrolyte battery according to the present invention.

FIG. 2 is a sectional view of a main part showing a solid electrolyte battery according to the present invention.

FIG. 3 is a cross-sectional view showing a conventional solid electrolyte battery.

[Explanation of symbols]

1: positive electrode current collector, 2: positive electrode, 3: solid electrolyte, 4: negative electrode, 5: negative electrode current collector

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 6/18 H01M 6/18 Z F term (Reference) 5H024 AA03 BB01 BB07 BB08 BB10 BB17 CC04 DD15 DD17 EE06 EE09 FF15 FF19 FF23 FF31 GG08 5H029 AJ06 AK03 AK05 AL03 AL04 AL06 AL12 AM03 AM07 AM12 AM16 BJ04 BJ12 CJ02 CJ08 CJ22 CJ23 CJ24 DJ04 DJ07 DJ08 DJ09 DJ13 EJ01 EJ06 EJ12 5H050 AA12 BA15 CA02 CB03 DA10 FA10

Claims (11)

[Claims] 1. A unipolar electrode comprising a porous structure of an active material and a particle binder, a solid electrolyte layer comprising an ion-conductive substance adhered to the surface of a void of the porous structure, It has another active material and another polar electrode made of a filling material filled in the void portion of the porous structure, and a current collector is provided on the one polar electrode and the other polar electrode. Solid electrolyte battery. 2. The solid electrolyte battery according to claim 1, wherein an electron conductivity-imparting substance is added to the active material of the porous structure. 3. The solid electrolyte battery according to claim 1, wherein the particle binding material comprises the ion conductive material and / or a dielectric material. 4. The method according to claim 1, wherein the ion conductive material is crystallized glass,
The solid electrolyte battery according to claim 1, comprising one or more of low-melting glass and a polymer. 5. The solid electrolyte battery according to claim 3, wherein the dielectric material is made of one or more of a low-melting glass and a metal alkoxide oxide obtained by a sol-gel method. 6. The solid electrolyte battery according to claim 1, wherein the particle binder is added to the solid electrolyte layer. 7. The solid electrolyte battery according to claim 1, wherein the electron conductivity-imparting substance is added to another active material of the other polarity side electrode. 8. The solid electrolyte battery according to claim 1, wherein the filling material comprises an ion conductive material and / or a dielectric material. 9. The method according to claim 9, wherein the ion conductive material is crystallized glass,
9. The solid electrolyte battery according to claim 8, comprising one or more of low-melting glass, polymer, gel, and non-aqueous electrolyte. 10. The method according to claim 1, wherein the dielectric material is low-melting glass, sol-
9. The solid electrolyte battery according to claim 8, comprising one or more of a metal alkoxide oxide and an organic solvent by a gel method. 11. A porous structure is formed by firing a formed form of an active material powder containing a particle binder and an organic binder, and the solid electrolyte powder containing the particle binder is viscous with a solvent. Impregnated into the porous structure and fired to apply a solid electrolyte layer to the surface of the void portion of the porous structure, and further make another active material powder containing a filling material into a viscous liquid with a solvent. And filling the voids of the porous structure and firing the porous structure.