JP2009252548A - Solid type battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid type battery which suppresses the electrolysis of a fluid sealant and secures its insulation in the long run even in a solid type battery which has a bipolar structure and is sealed by a fluid sealant. <P>SOLUTION: The solid type battery comprises: a power generation element of a bipolar structure, in which two or more layers of power generation units with a positive electrode layer, a solid electrolyte membrane, and a negative electrode layer laminated in this order laminated, a bipolar layer is arranged among the two or more power generation units, and further power collectors are respectively arranged on the outermost layer of the two or more layers of power generation units; a battery case which contains the power generation element; and a fluid seal layer which comprises a fluid sealant which allows the generation element to be immersed in the battery case and which has a property not to react the solid electrolyte membrane, wherein the fluid seal layer is airtightly divided into at least two or more layers by the bipolar layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  Even if the present invention has a bipolar structure and is a solid battery sealed with a fluid sealant, it can suppress the electrolysis of the fluid sealant and ensure insulation over a long period of time. The present invention relates to a solid-state battery that can be used.

  With the rapid spread of information-related equipment and communication equipment such as personal computers, video cameras, and mobile phones in recent years, development of batteries that are used as power sources has been regarded as important. Also in the automobile industry and the like, development of high-power and high-capacity batteries for electric vehicles or hybrid vehicles is being promoted. Currently, lithium batteries are attracting attention among various batteries from the viewpoint of high energy density.

  The lithium battery currently on the market uses an organic electrolyte that uses a flammable organic solvent as a solvent. Improvement is required.

  In contrast, an all-solid-state lithium battery in which the liquid electrolyte is changed to a solid electrolyte to make the battery all solid does not use a flammable organic solvent in the battery. It is considered to be excellent in productivity. However, when a sulfide-based solid electrolyte membrane is used as the solid electrolyte membrane, hydrogen sulfide is generated when the sulfide-based solid electrolyte membrane comes into contact with moisture in the air, and the performance of the sulfide-based solid electrolyte membrane There has been a problem that the material deteriorates significantly.

In order to solve such a problem, a solid battery in which a power generation element including a positive electrode, a sulfide-based solid electrolyte membrane, and a negative electrode is sealed with a sealant is known. For example, Patent Document 1 discloses an all-solid-state lithium battery in which a power generation element is sealed using a high-temperature curable resin. Since this all solid lithium battery protects the power generation element using a sealant, it has an advantage that it is possible to prevent the sulfide-based solid electrolyte membrane from deteriorating due to the ingress of moisture in the air. However, when a volume change (expansion / shrinkage) of the power generation element caused by movement of Li ions between the positive electrode and the negative electrode during charging / discharging or the like occurs, a crack occurs in the sealing portion formed by the high-temperature curable resin. In some cases, moisture in the air permeates through the gap, and there is a problem that the sulfide-based solid electrolyte membrane deteriorates.
Further, when an electrolyte other than the sulfide-based solid electrolyte is used as the solid electrolyte, there is a problem that the electrolyte is deteriorated when it comes into contact with moisture in the air.

  For this problem, an all-solid lithium battery sealed with a fluid sealing agent such as paraffin has been proposed. This all-solid-state lithium battery can flexibly cope with the volume change of the power generation element during charging.

  On the other hand, as a lithium battery for an electric vehicle, attention is focused on a stacked bipolar battery that can achieve a high energy density and a high output density. In the bipolar battery, a bipolar electrode in which a positive electrode active material layer is formed on one surface of a current collector and a negative electrode active material layer is formed on the other surface, and an electrolyte are alternately stacked.

  Even when a solid electrolyte is used as the electrolyte of the bipolar battery, there is a problem that the solid electrolyte deteriorates due to moisture in the air, as in the case of the solid battery described above.

  In order to solve this problem, a method of sealing a bipolar battery using a fluid sealant having fluidity such as paraffin has been proposed. However, a high voltage is applied in the case of a bipolar battery. In this case, there is a problem that the fluid sealing agent is electrolyzed and the insulating property cannot be maintained, and degradation of the solid electrolyte is caused by the decomposition product.

  Patent Document 2 discloses a bipolar battery that ensures insulation against a high voltage, but does not solve the above problem because a solid electrolyte is not used as the electrolyte.

JP-A-6-275247 JP-A-2005-310402 JP 2005-63775 A

  The present invention has been made in view of the above problems, and suppresses electrolysis of a fluid sealant even in a solid battery having a bipolar structure and sealed with a fluid sealant. The main object of the present invention is to provide a solid-state battery capable of ensuring insulation over a long period of time.

  To achieve the above object, the present invention provides a plurality of power generation units in which a positive electrode layer, a solid electrolyte membrane, and a negative electrode layer are stacked in this order, and a bipolar layer is disposed between the plurality of power generation units. Further, the outermost layer of the multi-layer power generation unit has a bipolar structure power generation element in which current collectors are respectively disposed, a battery case for storing the power generation element, and the power generation element in the battery case. And a fluidity sealing layer made of a fluidity sealing agent that does not react with the solid electrolyte membrane, and the bipolar layer causes the fluidity sealing layer to be at least Provided is a solid-state battery characterized in that it is divided into two or more layers in a sealed state.

  According to the present invention, the voltage applied to each fluid sealing layer is limited by separating the fluid sealing layer in a sealed state by the bipolar layer, so that the fluidity even when used under high voltage. Electrolysis of the fluid sealant filled in the sealing layer can be prevented. Thereby, insulation can be ensured. In addition, the deterioration of the electrolyte membrane due to the electrolytic product can be suppressed.

  In the said invention, it is preferable that the said solid electrolyte membrane is a sulfide type solid electrolyte membrane. This is because the present invention exhibits a greater effect when used for a solid-state battery having a sulfide-based solid electrolyte membrane.

  In the said invention, it is preferable that the said fluid sealing agent is a hydrophobic liquid. This is because moisture in the air can be prevented from coming into contact with the solid electrolyte membrane.

  The present invention has an effect that the insulating property can be ensured even in a high voltage state by separating the fluid sealing layer in a sealed state by the bipolar layer.

  The solid state battery of the present invention will be described in detail below.

  In the solid state battery of the present invention, a plurality of power generation units in which a positive electrode layer, a solid electrolyte membrane, and a negative electrode layer are stacked in this order are stacked, and a bipolar layer is disposed between the plurality of power generation units. In the outermost layer of the multiple-layer power generation unit, a bipolar structure power generation element in which a current collector is disposed, a battery case that houses the power generation element, and the power generation element are immersed in the battery case, And a solid state battery having a bipolar structure having a fluid sealing layer made of a fluid sealing agent having a property of not reacting with the solid electrolyte membrane, and wherein a plurality of the power generation units are stacked via the bipolar layer. However, the bipolar sealing layer is characterized in that the fluid sealing layer is separated into at least two layers in a sealed state.

FIG. 1 is a schematic cross-sectional view showing an example of a solid state battery of the present invention. As shown in FIG. 1A, the solid battery 1 includes a plurality of power generation units 5 each including a positive electrode layer 2, a solid electrolyte membrane 3, and a negative electrode layer 4. In addition, a power generation element 8 in which a bipolar layer 6 is disposed and a current collector 7 (a positive current collector 7a and a negative current collector 7b in the drawing) is disposed in the outermost layer of each of the plurality of power generation units 5. And a battery case 9 that houses the power generation element 8 and a fluid sealing layer 10 made of a fluid sealing agent that immerses the power generation element 8 in the battery case. The power generation element 8 has a bipolar structure in which a plurality of power generation units 5 are stacked via a bipolar layer 6. In addition, the current collector 7 is usually provided with an electrode tab 21 for electrical connection and extraction of current.
The fluid sealing layer 10 is divided into at least two layers in a sealed state by the bipolar layer 6p. (In the figure, the fluid sealing layers 10a and 10b).
FIG. 1A shows an example in which an open battery case is used, and FIG. 1B shows an example in which a sealed battery case is used. Further, reference numerals not described in FIG. 1B are the same as those in FIG.

According to the present invention, the voltage applied to the fluid sealing agent in the fluid sealing layer is limited by partitioning the fluid sealing layer with the bipolar layer in a sealed state. Decomposition is unlikely to occur. Thereby, insulation can be ensured over a long period of time. In addition, it is possible to suppress the deterioration of the solid electrolyte membrane due to the reaction between the decomposition product of the fluid sealant and the solid electrolyte membrane.
Hereinafter, the solid state battery of the present invention will be described in detail.

In the present invention, as shown in FIG. 1, the bipolar layer is stretched and brought into close contact with the inner wall of the battery case, thereby separating the fluid sealing layer in a sealed state. This is because the voltage applied to each of the separated fluid sealing layers is restricted by sealing with the bipolar layer, so that the fluid sealing agent can be prevented from being decomposed.
Moreover, even if it is a case where an impurity arises in a fluid sealing agent by making it a sealing state, there also exists an advantage that it can suppress spreading | diffusion to the whole.

  The sealing method using the bipolar layer may be the same as a method for forming a general liquid-tight state such as forming using a bipolar layer having an outer diameter equal to the inner diameter of the battery case. At this time, a seal layer may be formed between the bipolar layer and the inner wall of the battery case.

  In the power generation element used in the present invention, a plurality of the above power generation units are stacked via a bipolar layer. The number of power generation units to be stacked is preferably 2 or more, assuming an automotive application, and is preferably about 10 to 100, and more preferably about 70 to 80.

  In the present invention, the number of power generation units in the fluid sealing layer that is partitioned in a sealed state by the bipolar layer is such that the voltage applied to the fluid sealing agent in the fluid sealing layer does not cause electrolysis. Although it will not be specifically limited if it becomes a grade, It exists in the range of 1-50 in a fluid sealing layer, Especially in the range of 2-20, especially in the range of 5-10. It is preferable that it is divided so as to. When the number of power generation units in the fluid sealing layer exceeds the above range, the voltage applied to the fluid sealing agent in the partitioned fluid sealing layer may increase and may be electrolyzed. Because. This is because if it is less than the above range, there is a problem that the cost is high.

  Below, each structure of the solid-state battery of this invention is each demonstrated.

  In addition, the solid-state battery of this invention has a big characteristic in using the fluid sealing agent mentioned later. Therefore, the type of the ionic conductor in the solid battery is not particularly limited, but Li ion is particularly preferable. That is, the solid state battery of the present invention is preferably an all solid state lithium battery. This is because the battery can have a high energy density. Further, the solid state battery of the present invention may be a primary battery or a secondary battery, but among them, a secondary battery is preferable. For example, it is useful as a vehicle battery. Hereinafter, the material of the power generation element will be described focusing on the case of a lithium battery.

1. Power Generation Element The power generation element used in the solid-state battery of the present invention includes a plurality of power generation units in which a positive electrode layer, a solid electrolyte membrane, and a negative electrode layer are stacked in this order, and a bipolar layer is interposed between the plurality of power generation units. In addition, a current collector is disposed on each outermost layer of the plurality of power generation units.

a. Bipolar layer The bipolar layer used in the present invention is disposed between a plurality of power generation units described later, and a part or all of them are sealed with at least two fluid sealing layers described later. They are separated by state.
In the present invention, the bipolar layer used to divide the fluid sealing layer into at least two layers in a sealed state is referred to as a “first bipolar layer”, and the other bipolar layer is referred to as a “second bipolar layer”. explain.

(I) First Bipolar Layer Examples of the material of the first bipolar layer used in the present invention include Al, Ti, SUS, Ni, Cu and the like, and in particular, Ni and SUS are oxidation resistance and reduction resistance. preferable.

  Further, the shape of the first bipolar layer used in the present invention is such that the outer diameter is equal to the inner diameter of the battery case or slightly smaller than the inner diameter of the battery case, and has a certain degree of rigidity. If it is the shape which can seal a fluid sealing layer, it will not specifically limit, A foil shape etc. are mentioned.

In the present invention, as shown in FIG. 2, the first bipolar layer (bipolar layer 6p) may have a hollow structure, and the fluid sealing layer 10c may be introduced into the bipolar layer 6p. Here, it is assumed that the fluid sealing layer 10c inside the bipolar layer 6p is connected to either the adjacent fluid sealing layer 10a or the fluid sealing layer 10b.
By having such a structure, the convection of the fluid sealant occurs due to the temperature difference of each layer generated when the battery is driven, and the temperature inside the solid battery can be made constant, so that the cooling performance can be improved. It becomes possible.

  The thickness of the first bipolar layer is preferably in the range of 1 μm to 1000 μm, more preferably in the range of 10 μm to 500 μm, and particularly preferably in the range of 15 μm to 100 μm. This is because if it is less than the above range, the durability is weak and it is difficult to maintain the sealed state of the fluid sealing layer, and if it exceeds the above range, the volume and weight of the solid battery increase. .

(Ii) Second Bipolar Layer The material of the second bipolar layer used in the present invention can be the same as that described in the above-mentioned section “(i) First Bipolar Layer”. Description is omitted.

  The shape of the second bipolar layer used in the present invention can be the same as that of a general bipolar layer, and examples thereof include a foil-like thin film and a mesh shape.

  The thickness of the second bipolar layer used in the present invention is preferably in the range of 0.01 μm to 1000 μm, more preferably in the range of 0.1 μm to 100 μm, and particularly preferably in the range of 0.5 μm to 10 μm.

b. Next, the power generation unit used in the present invention will be described. The power generation unit used in the present invention has a positive electrode layer, a solid electrolyte membrane, and a negative electrode layer laminated in this order.

  The solid electrolyte membrane used in the present invention can be the same as the solid electrolyte membrane used in a general solid lithium battery, and is not particularly limited. A sulfide-based solid electrolyte membrane or an oxide-based electrolyte is not limited. Examples include membranes. A sulfide-based solid electrolyte membrane can be cited as a more effective example of the present invention. This is because the sulfide-based solid electrolyte membrane generates hydrogen sulfide when it reacts with moisture in the air, which significantly deteriorates the performance of the sulfide-based solid electrolyte membrane.

The sulfide-based solid electrolyte membrane used in the present invention is not particularly limited as long as it contains a sulfur component and has ionic conductivity. Specific examples of the material for the sulfide-based solid electrolyte membrane include those having Li, S, and the third component A. Examples of the third component A include at least one selected from the group consisting of P, Ge, B, Si, I, Al, Ga, and As. Specific examples of the sulfide-based solid electrolyte membrane include Li ₂ S—P ₂ S ₅ , 70Li ₂ S-30P ₂ S ₅ , 80Li ₂ S-20P ₂ S ₅ , Li ₂ S—SiS ₂ , LiGe _{0. .25} P _0.75 S _{4 and the} like, and 70Li ₂ S-30P ₂ S ₅ is particularly preferable. This is because a solid electrolyte membrane having high ionic conductivity can be obtained.

  Examples of the method for producing a sulfide-based solid electrolyte include a method of vitrifying a raw material containing Li, S, and the third component A with a planetary ball mill, or a method of vitrifying by melting and quenching. be able to. In the production of the sulfide solid electrolyte, heat treatment may be performed for the purpose of improving performance. Examples of the method for forming a sulfide-based solid electrolyte membrane include a method of pelletizing a sulfide-based solid electrolyte by uniaxial compression molding. The thickness of the sulfide-based solid electrolyte membrane is not particularly limited, but is, for example, in the range of 0.1 μm to 1000 μm, and particularly preferably in the range of 0.1 μm to 300 μm.

As what is used for an oxide type solid electrolyte membrane, for example, Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) ₃ , Li _1.5 Al _0.5 Ti _1.5 (PO ₄ ) ₃ , Li _0.5 La _0.5 TiO _{3 and the} like.

The positive electrode layer used in the present invention may be the same as the positive electrode layer used in a general solid battery. The positive electrode layer has at least a positive electrode active material. Examples of the positive electrode active material include LiCoO ₂ , LiMnO ₂ , Li ₂ NiMn ₃ O ₈ , LiVO ₂ , LiCrO ₂ , LiFePO ₄ , LiCoPO ₄ , LiNiO ₂ , LiNi _1/3 Co _1/3 Mn _1/3 O. _{2 and the} like, and LiCoO ₂ is particularly preferable. The positive electrode layer may contain a conductive material in order to improve conductivity. Examples of the conductive material include acetylene black and carbon fiber.

  Although it does not specifically limit as a film thickness of the said positive electrode layer, Usually, it exists in the range of 1 micrometer-100 micrometers. Moreover, as a formation method of the said positive electrode layer, the method of compression-molding powder, such as said positive electrode active material, etc. can be mentioned, for example.

The negative electrode layer used in the present invention may be the same as the negative electrode layer used in a general solid battery. The negative electrode layer has at least a negative electrode active material. Examples of the negative electrode active material include metal-based active materials and carbon-based active materials. Examples of the metal-based active material include In, Al, Si, and Sn. In particular, In is preferable. The metal active material may be an inorganic oxide active material such as Li ₄ Ti ₅ O ₁₂ . On the other hand, examples of the carbon-based active material include mesocarbon microbeads (MCMB), highly oriented graphite (HOPG), hard carbon, and soft carbon.

  Further, the negative electrode layer used in the present invention may be a metal film of a metal-based active material, or may be a compression-molded powder of a metal-based active material or a carbon-based active material. Specific examples of the metal film of the metal-based active material include metal foils, plating foils, vapor-deposited foils, and the like of the above-described metal-based active materials. Among these, metal foils of the metal-based active material are preferable. In addition, for example, when a negative electrode layer is formed by compression molding powder of a metal-based active material, a conductive material may be added in order to improve conductivity. Examples of the conductive material include acetylene black and carbon fiber.

  Although it does not specifically limit as a film thickness of the said negative electrode layer, Usually, it exists in the range of 1 micrometer-100 micrometers.

c. Current Collector The current collector used in the present invention is disposed in the outermost layer of the above-described power generation unit, and as shown in FIG. 1 (a), the positive electrode current collector is disposed on the positive electrode layer side of the outermost layer. The negative electrode current collector 7b is arranged on the negative electrode layer side of the outermost layer 7a.
Examples of the material of the positive electrode current collector include SUS, and examples of the shape of the positive electrode current collector include a foil shape and a mesh shape.
Examples of the material for the negative electrode current collector include SUS, and examples of the shape of the negative electrode current collector include a foil shape and a mesh shape.

2. Fluidity sealing layer The fluidity sealing layer used for this invention consists of a fluidity sealing agent which has a property which a power generation element is immersed in a battery case, and does not react with the solid electrolyte membrane mentioned later. In the present invention, “does not react with the solid electrolyte membrane” means that it does not substantially deteriorate the function of the solid electrolyte membrane by reacting with the solid electrolyte membrane. The fluid sealant used in the present invention has fluidity. “Having fluidity” means that it is not solid or gas, and means that it can flexibly follow the volume change of the power generation element accompanying charging and discharging. Accordingly, the fluid sealant in the present invention includes a dispersion system such as a sol, a gel, and an emulsion in addition to a normal liquid (organic solvent). Moreover, the material excellent in insulation is normally used for the fluid sealing agent in this invention.
Hereinafter, the fluid sealant used in the present invention will be described separately for a case where the battery case is an open type and a case where the battery case is a sealed type.

(I) When the battery case is an open type When the battery case is an open type, as shown in FIG. 1A described above, the fluid sealant comes into contact with the atmosphere (air). Therefore, it is preferable that the fluid sealant has high hydrophobicity. More specifically, the fluid sealant is preferably a hydrophobic liquid. This is because moisture in the air can be prevented from coming into contact with the solid electrolyte membrane.

  In the present invention, the amount of water contained in the fluid sealant is preferably small. Specifically, it is preferably 100 ppm or less, particularly 50 ppm or less, particularly preferably 30 ppm or less. This is because when the amount of water contained in the fluid sealant is too large, the deterioration of the solid electrolyte membrane easily proceeds.

The solubility of the fluid sealant in water (water vapor) is, for example, 1% (w / w) or less, particularly 0.5% (w / w) or less, particularly 0 at 25 ° C. and 1 atm. .1% (w / w) or less is preferable. In general, as an index representing the hydrophobicity of an object, there is a method of evaluation using a partition coefficient of a fluid sealant with respect to a mixed solvent of n-octanol and water. In the present invention, LogP _ow of flowable sealant, for example 0 or more and preferably 1 or more, and particularly preferably 2 or more.

  Examples of the hydrophobic liquid include chain saturated hydrocarbons, cyclic saturated hydrocarbons, and nonpolar liquids.

  As long as the chain saturated hydrocarbon has fluidity, it may have a straight chain structure or a branched structure. Furthermore, the fluid sealant may be a single chain saturated hydrocarbon or a mixture of a plurality of chain saturated hydrocarbons as long as it has fluidity.

  Examples of the simple chain saturated hydrocarbon include pentane, hexane, heptane, octane, nonane, decane, undecane, and dodecane. On the other hand, examples of the mixture of a plurality of chain saturated hydrocarbons include liquid paraffin. Liquid paraffin generally refers to a mixture of chain saturated hydrocarbons having 20 or more carbon atoms and liquid at room temperature. In the present invention, the hydrophobic liquid is preferably liquid paraffin.

Specific examples of the cyclic saturated hydrocarbon include cycloalkanes. Examples of the cycloalkane include cyclopentane, cyclohexane, cycloheptane, and cyclooctane.
Examples of the nonpolar liquid include benzene, toluene, diethyl ether, chloroform, ethyl acetate, tetrahydrofuran, and methyl chloride.
In the present invention, a dispersible fluid sealant such as a sol, gel, or emulsion can also be used.

(Ii) When the battery case is a sealed type When the battery case is a sealed type, the fluid sealant basically does not contact the atmosphere (air) as shown in FIG. Therefore, the kind of fluid sealant is not particularly limited as long as it has a property that does not react with a solid electrolyte membrane described later. Among them, in the present invention, it is preferable that the fluid sealant has high hydrophobicity, and more specifically, the fluid sealant is preferably a hydrophobic liquid. For example, even if air remains in the positive electrode layer or the like, it can be easily removed, and moisture can be prevented from coming into contact with the solid electrolyte membrane. In addition, since the kind etc. of hydrophobic liquid are the same as the content mentioned above, description here is abbreviate | omitted.

3. Battery Case Next, the battery case used in the present invention will be described. The battery case used in the present invention houses a power generation element and a fluid sealant. The battery case used in the present invention may be an open battery case in which the atmosphere and the fluid sealant can be in contact with each other, or may be a sealed battery case in which the battery case cannot be contacted.

  The battery case is not particularly limited as long as it can store a power generation element and a fluid sealant. For example, a battery case for a laminate pack, a battery case for a coin cell, a vent hole A battery case for an air battery having The battery case material and the like are the same as those used for general battery cases.

4). Solid-state battery The solid-state battery of the present invention may be an open-type solid battery as illustrated in FIG. 1 (a), or a closed-type battery as illustrated in FIG. 1 (b). It may be a solid battery.
This is because in the case of an open-type solid battery, a sudden change in internal pressure can be alleviated even when a volume change of the power generation unit accompanying charge / discharge or the like occurs. Specifically, as shown in FIG. 1A described above, a solid battery including a battery case 9 having a ventilation hole can be given. In an open type solid battery, the diameter of the vent is preferably small. This is because volatilization of the fluid sealant can be suppressed. The diameter of the vent hole is not particularly limited as long as a rapid change in internal pressure can be mitigated.

  On the other hand, in the case of a sealed solid battery, moisture in the air can be prevented from entering the battery. Furthermore, volatilization of the fluid sealant can be prevented. Specifically, as shown in FIG. 1B described above, a solid type battery including a sealed battery case 9 can be exemplified. Moreover, it is preferable that the sealed solid battery further includes an internal pressure adjusting means. This is because a sudden change in internal pressure can be alleviated even when the volume of the power generation unit is changed due to charging / discharging or the like.

Specific examples of the internal pressure adjusting means include means using a partition plate 11 and a spring 12 as shown in FIG. For example, when the power generation unit expands, the partition plate 11 is pushed by the fluid sealant, and the spring 12 contracts, so that the rapid increase in internal pressure is alleviated. On the other hand, when the power generation unit contracts, the spring 12 is extended, and the partition plate 11 presses the fluid sealant, so that the rapid decrease in internal pressure is alleviated. On the other hand, as shown in FIG. 3 (b), even if an inert gas 13 containing no moisture is enclosed in a sealed battery case 9 and the internal pressure is adjusted via the inert gas 13. good. In this case, since the fluid sealant does not come into contact with the internal pressure adjusting means, there is an advantage that contamination of the fluid sealant can be prevented. As another internal pressure adjusting means, for example, a means for providing a resin balloon or the like instead of the partition plate and the spring, and a means for using a stretchable material for the battery case itself can be cited.
In addition, the code | symbol which is not demonstrated is the same as that of FIG.

  In the solid-state battery of the present invention, other than the fluid sealing layer, the power generation element, and the battery case described above, necessary configurations can be appropriately added. For example, you may have a stirring means, a temperature adjustment means, a guide means, etc. Such stirring means, temperature adjusting means, and guide means will be described below.

  The solid state battery of the present invention preferably has a stirring means for stirring the fluid sealing agent. This is because, for example, the temperature can be easily equalized when the power generation unit is heated or cooled via the fluid sealant. Since the conventional sealing agent uses a solid resin or the like that does not have fluidity, there is a problem that even if the power generation unit is heated or cooled via the sealing agent, the temperature is uneven. In contrast, in the present invention, by stirring the fluid sealant, the temperature of the power generation unit can be adjusted uniformly, and the power generation efficiency can be improved.

  The stirring means is not particularly limited as long as it can stir the fluid sealant. For example, a means for circulating the fluid sealant through an external path connected to the battery case, etc. Can be mentioned. Specifically, as shown in FIG. 4, a means for circulating the fluid sealant through an external path 14 connected to the battery case 9 can be exemplified. In the present invention, liquid circulation means (for example, a motor) for circulating the fluid sealing agent may be disposed in the external path 14. In the solid battery shown in FIG. 4, the fluid sealant inside the battery case 9 is heated and raised by the power generation unit, and conversely, the fluid sealant inside the external path 14 is natural. It descends by cooling. Therefore, it is possible to gently circulate the fluid sealant using the difference in specific gravity without providing any liquid circulation means. Another example of the stirring means is a means for installing a screw or the like inside the battery case.

  In the present invention, it is preferable to have a temperature adjusting means for heating or cooling the fluid sealant. This is because, by adjusting the temperature of the power generation unit via the fluid sealant, charging / discharging and the like can be performed under optimal temperature conditions, and power generation efficiency can be improved. Further, since the fluid sealant is in direct contact with the power generation unit, there is an advantage that the temperature of the power generation unit can be adjusted efficiently. As a method for heating / cooling the fluid sealant, for example, a method for heating / cooling the fluid sealant via a battery case, a temperature adjusting tube is installed inside the battery case, Examples thereof include a method of heating / cooling the fluid sealant through a medium / refrigerant and a method of heating / cooling the fluid sealant through the external path described above. In the case of an in-vehicle solid battery, the fluid sealant may be cooled through a radiator, for example. In particular, the solid-state battery of the present invention preferably has a temperature adjusting means and the above-described stirring means. It is because the advantage using the sealing agent which has fluidity | liquidity can fully be utilized.

  In the present invention, it is preferable that the power generation unit has guide means for releasing air bubbles on the bottom surface side of the battery case. This is because by providing the guide means, it is possible to prevent bubbles from remaining near the bottom surface of the battery case when the power generation unit is immersed in the fluid sealant. Specifically, as shown in FIG. 5, the power generation unit 5 may include a guide unit 15 having an electrode tab 21 on the bottom surface side of the battery case 9. Thereby, it is possible to suppress the bubbles 16 from remaining near the bottom surface of the battery case 9. Examples of the guide means shape include an inverted triangle. Further, a groove may be formed on the surface of the current collector or electrode tab to serve as guide means.

Further, normally, as shown in FIG. 1, electrode tabs for taking out current are electrically connected to the respective current collectors.
The shape of such an electrode tab can be the same as that used for a general solid battery, and examples thereof include a foil shape and a lead shape.
Moreover, as a material used for an electrode tab, it can be set as the thing similar to what is used for a general solid type battery, For example, Al, Ti, SUS, Ni, Cu etc. can be mentioned.

  In the present invention, as shown in FIG. 6, the electrode tab may be incorporated in a part of the battery case. This is because leakage of the fluid sealant can be prevented. In the solid-state battery as shown in FIG. 1B described above, the electrode tab 21 is disposed so as to penetrate the battery case 9, so even if the penetration portion is sealed with resin or the like, the resin tab or the like deteriorates. There is a possibility that the fluid sealant leaks from the through portion. On the other hand, in the solid-state battery as shown in FIG. 6, since the sealing of the penetrating portion is unnecessary, leakage of the fluid sealing agent can be surely prevented.

  Moreover, the solid-state battery of the present invention may have a dehydrating means for reducing the water content of the fluid sealant. In particular, when a sulfide-based solid electrolyte membrane is used, deterioration can be further prevented by providing a dehydrating means. Examples of the dehydrating means include a method of disposing a dehydrating agent inside the battery case. The dehydrating agent is not particularly limited as long as it has water absorption and does not adversely affect the fluid sealant, and a general dehydrating agent can be used. Specific examples include silica gel and molecular sieve.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

It is a schematic sectional drawing which shows an example of the solid battery of this invention. It is a schematic sectional drawing which shows the other example of the solid battery of this invention. It is explanatory drawing explaining the internal pressure adjustment means in this invention. It is explanatory drawing explaining the external path | route in this invention. It is explanatory drawing explaining the guide means in this invention. It is explanatory drawing explaining the battery case used for this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Solid type battery 2 ... Positive electrode layer 3 ... Solid electrolyte membrane 4 ... Negative electrode layer 5 ... Power generation unit 6, 6p ... Bipolar layer 7 ... Current collector 7a ... Positive electrode current collector 7b ... Negative electrode current collector 8 ... Power generation element 9 ... Battery case 10, 10a, 10b, 10c ... Fluid sealing layer 21 ... Electrode tab

Claims (3)

A plurality of power generation units in which a positive electrode layer, a solid electrolyte membrane, and a negative electrode layer are stacked in this order are stacked. A bipolar layer is disposed between the plurality of power generation units. The outer layer has a bipolar power generation element in which a current collector is disposed, a battery case that houses the power generation element, the power generation element immersed in the battery case, and a reaction with the solid electrolyte membrane A solid-state battery having a fluid sealing layer made of a fluid sealing agent having a non-performing property,
A solid-state battery characterized in that the fluid sealing layer is hermetically separated into at least two layers by the bipolar layer.   The solid state battery according to claim 1, wherein the solid electrolyte membrane is a sulfide-based solid electrolyte membrane.   The solid type battery according to claim 1, wherein the fluid sealant is a hydrophobic liquid.

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