JP2023090080A - METHOD FOR MANUFACTURING SOLID ELECTROLYTE LAYER - Google Patents

Abstract

To provide a manufacturing method of a solid electrolyte layer which enables the reduction in resistance of an all-solid battery chiefly.SOLUTION: The above problem is solved by providing a manufacturing method of a solid electrolyte layer to be used for an all-solid battery in this disclosure. The manufacturing method of a solid electrolyte layer comprises: a preparation step of preparing a slurry containing a solid electrolyte, a binder and a dispersion medium; a setting step of setting a support body having pores on a first mold releasing film; a coating step of coating the support body with the slurry to impregnate the slurry into the support body; a drying step of drying the support body coated with the slurry to remove the dispersion medium; and a press step of setting a second mold releasing film on a face of the support body having gone through the drying step on the side opposite to the first mold releasing film, and pressing the first mold releasing film, the support body and the second mold releasing film in a lamination direction.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a method for manufacturing a solid electrolyte layer.

All-solid-state batteries are batteries that have a solid electrolyte layer between the positive electrode layer and the negative electrode layer. Compared to liquid-based batteries, which have an electrolyte containing a flammable organic solvent, the advantage is that it is easier to simplify the safety device. have

For example, Patent Literature 1 discloses a nonwoven fabric and a solid electrolyte sheet containing a solid electrolyte on the surface and inside of the nonwoven fabric as a solid electrolyte layer used in an all-solid-state battery. Further, Patent Document 2 discloses, as a solid electrolyte layer used in an all-solid-state battery, a separator in which crystalline oxide-based inorganic solid electrolyte particles are supported in a single layer on a non-woven fabric.

JP 2016-031789 A JP 2020-188026 A

From the viewpoint of improving the performance of all-solid-state batteries, a solid electrolyte layer capable of reducing resistance is desired. The present disclosure has been made in view of the above circumstances, and a main object thereof is to provide a method for manufacturing a solid electrolyte layer capable of reducing the resistance of an all-solid-state battery.

In order to solve the above problems, the present disclosure provides a method for manufacturing a solid electrolyte layer used in an all-solid-state battery, comprising a preparation step of preparing a slurry containing a solid electrolyte, a binder and a dispersion medium; A placement step of placing a support having the A drying step of drying the processed support to remove the dispersion medium, and placing a second release film on the surface opposite to the first release film on the support after the drying. and a pressing step of pressing the first release film, the support, and the second release film in a stacking direction.

According to the present disclosure, since a support having pores is impregnated with a slurry containing a solid electrolyte, a solid electrolyte layer capable of reducing the resistance of an all-solid-state battery can be manufactured.

The present disclosure has the effect of providing a method for manufacturing a solid electrolyte layer that can reduce the resistance of an all-solid-state battery.

FIG. 3 is a flow diagram illustrating a method for manufacturing a solid electrolyte layer in the present disclosure; 1 is a schematic perspective view illustrating an all-solid-state battery in the present disclosure; FIG.

Hereinafter, the method for manufacturing the solid electrolyte layer according to the present disclosure will be described in detail.

FIG. 1 is a flow diagram illustrating a method for manufacturing a solid electrolyte layer in the present disclosure. As shown in FIG. 1, first, a slurry containing a solid electrolyte, a binder and a dispersion medium is prepared (preparation step). Then, a support having pores is placed on the first release film (placement step). Note that the placement process may be performed before the preparation process, or may be performed simultaneously with the preparation process. Next, the support is coated with the slurry to impregnate the support with the slurry (coating step). Next, the slurry-coated support is dried to remove the dispersion medium (drying step). Then, on the support after drying, the second release film is placed on the surface opposite to the first release film, and the first release film, the support, and the second release film are pressed in the stacking direction. (Pressing process). Thereby, a solid electrolyte layer arranged between the first release film and the second release film can be produced.

According to the present disclosure, since a support having pores is impregnated with a slurry containing a solid electrolyte, a solid electrolyte layer capable of reducing the resistance of an all-solid-state battery can be manufactured. Moreover, since a support is used, a thin solid electrolyte layer can be manufactured, and the resistance of the all-solid-state battery can be reduced. Furthermore, according to the present disclosure, since a support is used and densification is performed by pressing, the produced solid electrolyte layer can stand on its own, and when used to manufacture an all-solid-state battery, it is easy to handle. become good.

1. Preparation Step The preparation step in the present disclosure is a step of preparing a slurry containing a solid electrolyte, a binder and a dispersion medium.

(1) Solid electrolyte Solid electrolytes include inorganic solid electrolytes and organic solid electrolytes. Examples of inorganic solid electrolytes include sulfide solid electrolytes, oxide solid electrolytes, halide solid electrolytes, hydrogen boride solid electrolytes, and molten salts that are solid at room temperature. Organic solid electrolytes include, for example, flexible crystalline solid electrolytes. Among these, sulfide solid electrolytes are preferred because of their high ionic conductivity. One type of solid electrolyte may be used, or two or more types may be used.

A sulfide solid electrolyte usually contains sulfur (S) as a main component of the anion element. The sulfide solid electrolyte contains, for example, Li element, X element (X is at least one of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In), and S element. preferably. Moreover, the sulfide solid electrolyte may contain at least one of Cl element, Br element and I element as a halogen element. Moreover, the sulfide solid electrolyte may contain an O element.

Examples of sulfide solid electrolytes include Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -LiI, Li ₂ SP ₂ S ₅ -GeS ₂ , Li ₂ SP ₂ S ₅ - _Li2O , _Li2SP2S5 - _{Li2O -} LiI, _Li2SP2S5 -LiI _- LiBr _{, Li2S} - _SiS2 , _Li2S - _{SiS2 -} LiI, _Li2 S—SiS ₂ —LiBr, Li ₂ S—SiS ₂ —LiCl, Li ₂ S—SiS ₂ —B ₂ S ₃ —LiI, Li ₂ S—SiS ₂ —P ₂ S ₅ —LiI, Li ₂ S—B ₂ S ₃ , Li ₂ SP ₂ S ₅ -Z _m Sn (where m and n are positive numbers; Z is one of Ge, Zn, and Ga), Li ₂ S—GeS ₂ , Li ₂ S -SiS ₂ -Li ₃ PO ₄ , Li ₂ S-SiS ₂ -Li _x MO _y (where x and y are positive numbers, M is any of P, Si, Ge, B, Al, Ga, In ).

The composition of _the sulfide solid electrolyte _{is not} particularly limited _. S·(1−x)P ₂ S ₅ ) (0.7≦x≦0.8, 0≦y≦30, 0≦z≦30).

The solid electrolyte may be glass (amorphous), glass ceramics, or crystal. Glass is obtained, for example, by amorphizing raw materials. Glass-ceramics are obtained, for example, by heat-treating glass. A crystal can be obtained, for example, by heating the raw material of the solid electrolyte.

Examples of the shape of the solid electrolyte include particulate. The particle size (D50) of the solid electrolyte is, for example, 10 nm or more and 50 μm or less. D50 can be calculated from measurements using, for example, a laser diffraction particle size distribution meter and a scanning electron microscope (SEM). The ionic conductivity (25° C.) of the solid electrolyte is preferably high. The ionic conductivity (25° C.) of the solid electrolyte is, for example, 1×10 ⁻⁴ S/cm or more, and may be 1×10 ⁻³ S/cm or more. Moreover, the ratio of the solid electrolyte in the solid components of the slurry is, for example, 70% by weight or more and 99% by weight or less.

(2) Binder Binders include, for example, rubber-based binders such as butylene rubber (BR) and styrene-butadiene rubber (SBR), and fluoride-based binders such as polyvinylidene fluoride (PVdF). One type of binder may be used, or two or more types may be used. The ratio of the binder in the solid components of the slurry is, for example, 1% by weight or more and 30% by weight or less.

(3) Dispersion medium Examples of dispersion medium include esters such as butyl butyrate, dibutyl ether, and ethyl acetate, ketones such as diisobutyl ketone (DIBK), methyl ketone, and methyl propyl ketone, and aromatic hydrocarbons such as xylene, benzene, and toluene. , alkanes such as heptane, dimethylbutane and methylhexane, and amines such as tributylamine and allylamine. The proportion of the dispersion medium in the slurry is, for example, 60 parts by weight or more and 120 parts by weight or less when the solid component of the slurry is 100 parts by weight.

(4) Slurry Slurry may be purchased from a commercial product or prepared by yourself. In the latter case, examples of methods for preparing the slurry include a method of kneading a composition containing a solid electrolyte, a binder and a dispersion medium. Examples of kneading methods include methods using general kneading devices such as dissolvers, homomixers, kneaders, roll mills, sand mills, attritors, ball mills, vibrator mills, high-speed impeller mills, ultrasonic homogenizers, and shakers. be done.

2. Arranging Step The arranging step in the present disclosure is a step of arranging a support having pores on the first release film.

A voided support may have a woven or non-woven structure. A woven fabric structure refers to a structure in which fibers (eg, resin fibers and glass fibers) are regularly arranged, and a non-woven fabric structure refers to a structure in which fibers (eg, resin fibers and glass fibers) are randomly arranged. Non-woven fabrics can be mentioned as substrates in the present disclosure.

The porosity of the support is not particularly limited, but may be, for example, 30% or more, may be 50% or more, or may be 70% or more. On the other hand, the porosity of the support is, for example, 90% or less. The porosity of the support can be calculated from the density and true density of the support.

The thickness of the support is, for example, 10 μm or more, and may be 20 μm or more. On the other hand, the thickness of the support is, for example, 50 μm or less.

The release film preferably has, for example, a film and a coating film containing a release agent. Examples of film materials include resins such as polyethylene terephthalate (PET) and polyester. Further, examples of release agents include silicone-based release agents.

It is preferable that the first release film has a small peeling force with respect to a predetermined tape. The peel strength of the first release film is, for example, 0.15 N/50 mm or less, and may be 0.10 N/50 mm or less, against a polyester adhesive tape (No. 31B, manufactured by Nitto Denko). If the peeling force is too large, defects may occur in the solid electrolyte layer when the first release film is peeled off after the pressing step described later. The peel strength can be measured, for example, by the method described in JIS Z 0237:2009 (Testing methods for adhesive tapes and adhesive sheets).

Although the thickness of the first release film is not particularly limited, it is, for example, 10 μm or more and 30 μm or less.

3. Coating Step The coating step in the present disclosure is a step of applying slurry to a support and impregnating the support with the slurry. Through this step, the pores of the support can be filled with the solid electrolyte.

The slurry coating method is not particularly limited, and examples thereof include a doctor blade method, a die coating method, a gravure coating method, a spray coating method, an electrostatic coating method, and a bar coating method.

4. Drying Step The drying step in the present disclosure is a step of drying the slurry-coated support to remove the dispersion medium.

The drying method is not particularly limited as long as the dispersion medium can be volatilized, and examples thereof include general methods such as hot air/hot air drying, infrared drying, reduced pressure drying, and dielectric heating drying. Examples of the drying atmosphere include an inert gas atmosphere such as an Ar gas atmosphere and a nitrogen gas atmosphere, an air atmosphere, and a vacuum.

Although the drying temperature is not particularly limited, it is preferably a temperature at which the solid electrolyte does not deteriorate. The drying temperature is, for example, 100° C. or higher and 200° C. or lower. The drying time is not particularly limited and can be adjusted as appropriate.

5. Pressing step In the pressing step of the present disclosure, in the support after drying, a second release film is placed on the surface opposite to the first release film, and the first release film, the precursor layer and the second release film are This is a step of pressing in the stacking direction of the release film. In the present disclosure, the pressing process can obtain the solid electrolyte layer disposed between the first release film and the second release film.

The second release film is the same as the first release film described above. The materials of the second release film and the first release film may be the same or different. Moreover, the thickness of the second release film and the thickness of the first release film may be the same or different.

The pressing method is not particularly limited as long as it is a method capable of applying pressure in the stacking direction of the first release film, the support and the second release film. Examples of the pressing method include roll pressing and flat plate pressing. In the case of roll press, the linear pressure is, for example, 1 ton/cm or more and 8 ton/cm or less. Also, the press may be a hot press.

When using the produced solid electrolyte layer in an all-solid battery, the first release film and the second release film are usually peeled off.

6. Solid Electrolyte Layer The solid electrolyte layer produced by the above process contains a support, a solid electrolyte and a binder. Moreover, a dispersion medium may be contained as a residual component. The support, solid electrolyte, binder and dispersion medium are as described above.

The thickness of the solid electrolyte layer is, for example, 10 μm or more, may be 15 μm or more, or may be 20 μm or more. On the other hand, the thickness of the solid electrolyte layer is, for example, 50 μm or less, may be 40 μm or less, or may be 30 μm or less. Moreover, the Young's modulus of the solid electrolyte layer is, for example, 1 GPa or more and 100 GPa or less.

Moreover, since the solid electrolyte layer in the present disclosure contains a support, it can stand on its own. Therefore, when used in an all-solid-state battery, which will be described later, the area in plan view can be made larger than those of the positive electrode layer and the negative electrode layer.

7. All-Solid Battery The solid electrolyte layer in the present disclosure is used for all-solid-state batteries. FIG. 2 is a schematic perspective view illustrating an all-solid-state battery in the present disclosure. The all-solid-state battery 10 shown in FIG. 2 has a positive electrode layer 1 , a negative electrode layer 2 , and a solid electrolyte layer 3 arranged between the positive electrode layer 1 and the negative electrode layer 2 . The solid electrolyte layer 3 is a solid electrolyte layer manufactured by the method described above. The all-solid-state battery 10 also has a positive electrode current collector 4 that collects current from the positive electrode layer 1 and a negative electrode current collector 5 that collects current from the negative electrode layer 2 .

In the present disclosure, since the solid electrolyte layer is the solid electrolyte layer manufactured by the method described above, the all-solid battery has a low resistance.

Further, as shown in FIG. 2, in the all-solid-state battery according to the present disclosure, the area of the solid electrolyte layer 3 is larger than the area of the negative electrode layer 2 and the positive electrode layer 1 when viewed in plan along the thickness direction _DT . is preferably large. This is because the occurrence of an internal short circuit is suppressed.

The materials for the positive electrode layer and the negative electrode layer can be those conventionally used for all-solid-state batteries. In addition, all-solid-state batteries usually have a positive electrode current collector that collects current for the positive electrode layer and a negative electrode current collector that collects current for the negative electrode layer. Materials for the positive electrode current collector and the negative electrode current collector can be materials conventionally used for all-solid-state batteries. In addition, the shapes of the positive electrode current collector and the negative electrode current collector can be appropriately adjusted.

All-solid-state batteries in the present disclosure are typically all-solid-state lithium-ion secondary batteries. Applications of all-solid-state batteries are not particularly limited, but examples include power sources for vehicles such as hybrid vehicles (HEV), electric vehicles (BEV), gasoline vehicles, and diesel vehicles. In particular, it is preferably used as a drive power source for hybrid vehicles or electric vehicles. In addition, the all-solid-state battery according to the present disclosure may be used as a power source for mobile objects other than vehicles (for example, railroads, ships, and aircraft), and may be used as a power source for electric appliances such as information processing devices.

Note that the present disclosure is not limited to the above embodiments. The above embodiment is an example, and any device that has substantially the same configuration as the technical idea described in the claims of the present disclosure and produces the same effect is the present invention. It is included in the technical scope of the disclosure.

[Example 1]
(Preparation of solid electrolyte layer)
They were weighed so that the sulfide solid electrolyte was 99% by weight and the SBR binder was 1% by weight. These were added to butyl butyrate so that the solid content was 55% by weight, and subjected to ultrasonic dispersion treatment for 1 minute using an ultrasonic dispersion device. Thus, a solid electrolyte layer slurry was obtained. As the sulfide solid electrolyte, 15LiBr·10LiI·75 (0.75Li ₂ S·0.25P ₂ S ₅ ) glass ceramics having a particle diameter (D50) of 2.5 µm measured based on a laser diffraction/scattering method. It was used.

Next, a polyester nonwoven fabric (thickness 25 μm, porosity 80%, MD direction tensile strength 5 N / cm, CD direction tensile strength 1 N / cm ) was placed. Then, the solid electrolyte layer slurry was uniformly applied onto the nonwoven fabric by blade coating using an applicator. The basis weight including the nonwoven fabric was set to 5.0 mg/cm ² . Then, the nonwoven fabric was dried at 100° C. for 60 minutes to obtain a nonwoven fabric in which the pores were filled with the solid electrolyte. After that, another release film was overlaid on the nonwoven fabric and roll-pressed at a press pressure of 1 ton/cm. After pressing, the release films above and below the support were peeled off. A solid electrolyte layer was thus obtained. The resulting solid electrolyte layer had a thickness of 30 μm and could stand on its own. Moreover, no slurry component remained in the peeled release film, and all of the solid electrolyte could be transferred to the nonwoven fabric.

(Preparation of positive electrode)
LiNi _1/3 Co _1/3 Mn _1/3 O ₂ powder having a particle size (D50) of 5 μm measured by a laser diffraction/scattering method was used as the positive electrode active material. Next, the surface of the positive electrode active material was coated with LiNbO ₃ using a sol-gel method. As the sulfide solid electrolyte, the above glass ceramics was used. The positive electrode active material and the sulfide solid electrolyte were weighed so that the weight ratio was 75:25. Furthermore, 3 parts by weight of the SBR-based binder and 10 parts by weight of the conductive material (CNF) were weighed with respect to 100 parts by weight of the positive electrode active material. These were added to butyl butyrate so that the solid content was 60% by weight, and subjected to ultrasonic dispersion treatment for 1 minute using an ultrasonic dispersion device. Thus, a positive electrode slurry was obtained.

The obtained positive electrode slurry was uniformly applied onto a 15 μm thick aluminum foil (positive electrode current collector) by blade coating using an applicator so that the basis weight was 25 mg/cm ² . After that, it was dried at 100° C. for 60 minutes. As a result, a positive electrode having a positive electrode layer formed on an aluminum foil was obtained.

(Preparation of negative electrode)
As a negative electrode active material, Si powder having a particle size (D50) of 5 μm measured based on a laser diffraction/scattering method was used. As the sulfide solid electrolyte, the above glass ceramics was used. The negative electrode active material and the sulfide solid electrolyte were weighed so that the weight ratio was 50:50. Furthermore, 3 parts by weight of the SBR-based binder and 10 parts by weight of the conductive material (CNF) were weighed with respect to 100 parts by weight of the negative electrode active material. These were added to butyl butyrate so that the solid content was 40% by weight, and subjected to ultrasonic dispersion treatment for 1 minute using an ultrasonic dispersion device. A negative electrode slurry was thus obtained.

The obtained negative electrode slurry was uniformly applied onto a copper foil (negative electrode current collector) having a thickness of 25 μm by blade coating using an applicator so that the basis weight was 5 mg/cm ² . After that, it was dried at 100° C. for 60 minutes. As a result, a negative electrode having a negative electrode layer formed on the copper foil was obtained.

(Preparation of all-solid-state battery for evaluation)
The positive electrode layer was cut into squares of 4.0 cm×4.0 cm together with the aluminum foil, the negative electrode layer together with the copper foil of 4.0 cm×4.0 cm, and the solid electrolyte layer into squares of 4.4 cm×4.4 cm. A negative electrode layer, a solid electrolyte layer, and a positive electrode layer were laminated in this order, and roll-pressed at a pressure of 3 tons/cm to obtain a laminated electrode body. The laminated electrode body thus obtained was sealed with an exterior body made of an aluminum laminate film to which positive and negative terminals were attached in advance. Thus, an evaluation all-solid battery (all-solid lithium ion secondary battery) was produced.

[Comparative Example 1]
(Preparation of polymer solid electrolyte layer)
Polyethylene oxide (PEO; Mw is about 4,000,000) and lithium bistrifluoromethanesulfonylimide (Li-TFSI) were weighed in a molar ratio of EO units:TFSI=20:1. These were dissolved in acetonitrile to obtain a polymer electrolyte solution. Next, benzoyl peroxide (BPO, a radical polymerization initiator) was added to the polymer electrolyte solution so as to be 10% by weight with respect to the mixture of PEO and Li-TFSI, and stirred until a homogeneous solution was obtained. . The prepared solution was applied onto a release film (PET film) by a blade method using an applicator. Then, after natural drying, it was dried on a hot plate at 100° C. for 60 minutes. Thereby, a polymer solid electrolyte layer having a thickness of 50 μm was obtained. The resulting polymer solid electrolyte layer was self-supporting.

(Preparation of all-solid-state battery for evaluation)
An all-solid-state battery for evaluation was produced in the same manner as in Example 1, except that the polymer solid electrolyte layer was used as the solid electrolyte layer (SE layer).

[evaluation]
(Measurement of open circuit voltage)
The batteries for evaluation produced in Example 1 and Comparative Example 1 were restrained at a pressure of 100 MPa, and the open circuit voltage (OCV) was measured to confirm the presence or absence of a short circuit. Table 1 shows the results.

(Resistance measurement)
The all-solid-state battery for evaluation produced in Example 1 and Comparative Example 1 was restrained under a pressure of 100 MPa, and the resistance was measured. The measurement was performed according to the following procedures. First, the battery was CCCV charged to 4.5 V at a current rate of 16 mA (current cutoff value, 0.16 mA). Next, CCCV discharge was performed to 4.0 V at a current rate of 16 mA (current cutoff value, 0.16 mA). After discharging, it was left for 1 hour. Then, the battery was discharged under CC discharge, a current rate of 10 mA, and a 10-second cut, and the battery resistance was measured according to Ohm's law. Table 1 shows the results.

As shown in Table 1, the resistance of Example 1 was lower than that of Comparative Example 1. This is probably because the thickness of the SE layer (solid electrolyte layer) could be reduced by using the support (nonwoven fabric) having pores. In addition, it is considered that the solid electrolyte layer was denser because the solid electrolyte layer was produced in Example 1 by pressing. Furthermore, it is considered that the ionic conductivity of the sulfide solid electrolyte was higher than that of the polymer solid electrolyte. Moreover, in Example 1 and Comparative Example 1, the OCV was greater than 0 V, and no short circuit (internal short circuit) occurred. This confirmed that the occurrence of an internal short circuit can be suppressed by making the area of the SE layer larger than the areas of the positive electrode and the negative electrode.

[Example 2]
A solid electrolyte layer was produced in the same manner as in Example 1, except that the nonwoven fabric had a thickness of 10 μm and the slurry was uniformly applied so as to have a basis weight of 2.0 mg/cm ² . The resulting solid electrolyte layer had a thickness of 15 μm and could stand on its own. Moreover, no coating film remained on the peeled release film, and all of the sulfide solid electrolyte could be transferred to the nonwoven fabric.

[Comparative Example 2]
Except that the solid electrolyte slurry was uniformly applied to a 25 μm-thick release film (Therapeal WZ, manufactured by Toray) without using a nonwoven fabric so that the basis weight was 5.0 mg/cm ² . , a solid electrolyte layer was prepared in the same manner as in Example 1. The resulting solid electrolyte layer collapsed at the same time as the release film was peeled off, and could not stand on its own.

[Comparative Example 3]
A solid electrolyte layer was produced in the same manner as in Example 2, except that a SUS foil was used instead of the release film. The obtained solid electrolyte layer was able to stand on its own, but the peeled SUS foil had a residual coating film, and the nonwoven fabric side was see-through.

[Comparative Example 4]
After drying, a solid electrolyte layer was produced in the same manner as in Example 2, except that the nonwoven fabric was peeled off from the release film without being roll-pressed. The obtained solid electrolyte layer was able to stand on its own, but the coating film remained on the release film and the non-woven fabric was see-through.

[Comparative Example 5]
An all-solid-state battery for evaluation was produced in the same manner as in Example 1, except that the solid electrolyte layer produced in Comparative Example 4 was used as the solid electrolyte layer. The above-described open-circuit voltage measurement was performed on the obtained all-solid-state battery for evaluation, and the presence or absence of a short circuit was evaluated. It is shown in Table 2 together with the results of Example 1 and Comparative Example 1.

As shown in Table 2, in Comparative Example 5, although the area of the solid electrolyte layer was larger than the areas of the positive electrode and the negative electrode, the OCV was 0 V and a short circuit (internal short circuit) occurred. This is probably because the support (nonwoven fabric) could not be sufficiently filled with the solid electrolyte, resulting in insufficient insulation of the solid electrolyte layer. In Comparative Example 5, the resistance value could not be measured because an internal short circuit occurred.

Further, in Comparative Example 5, it is conceivable that the occurrence of short circuits can be suppressed by increasing the thickness of the solid electrolyte layer, but it is presumed that the battery resistance increases as the thickness increases. In addition, as shown in Comparative Example 4, the solid electrolyte layer produced without pressing was not sufficiently filled with the solid electrolyte in the nonwoven fabric, and the solid electrolyte layer had a large amount of voids. Therefore, it is presumed that the battery resistance increases due to an increase in the bending degree in the solid electrolyte layer and a decrease in the contact surface between the solid electrolyte layer and the active material layer.

DESCRIPTION OF SYMBOLS 1... Positive electrode layer 2... Negative electrode layer 3... Solid electrolyte layer 4... Positive electrode collector 5... Negative electrode collector 10... All-solid-state battery

Claims (1)

A method for producing a solid electrolyte layer used in an all-solid-state battery, comprising:
a preparation step of preparing a slurry containing a solid electrolyte, a binder and a dispersion medium;
an arranging step of arranging a support having pores on the first release film;
a coating step of coating the slurry on the support and impregnating the support with the slurry;
a drying step of drying the support coated with the slurry to remove the dispersion medium;
In the support after drying, a second release film is placed on the surface opposite to the first release film, and the first release film, the support, and the second release film are laminated in the stacking direction. A method for manufacturing a solid electrolyte layer, comprising a pressing step of pressing into the solid electrolyte layer.

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