KR20240034810A - Exterior materials for all-solid-state batteries and all-solid-state batteries - Google Patents

Abstract

Provided is an exterior material for an all-solid-state battery that can prevent defects such as damage from occurring. The present invention provides a solid battery comprising a base layer 11, a metal foil layer 12 laminated on the inner surface of the base layer 11, and a sealant layer 13 laminated on the inner surface of the metal foil layer 12. The target is the exterior material for an all-solid-state battery to enclose the main body (5). A heat-resistant gas barrier layer 21 made of resin is provided between the metal foil layer 12 and the sealant layer 13, and the heat-resistant gas barrier layer 21 has a Young's modulus at 90°C of both MD and TD of 1 GPa or more.

Description

Exterior materials for all-solid-state batteries and all-solid-state batteries

The present invention relates to exterior materials and all-solid-state batteries for all-solid-state batteries used as high-power batteries such as batteries for vehicles, batteries for portable devices such as mobile electronic devices, and batteries for storing regenerative energy.

Since lithium ion secondary batteries, which have been widely used in the past, use a liquid electrolyte as an electrolyte, there is a risk that the separator may be destroyed due to liquid leakage or generation of dendrites, and in some cases, ignition due to short circuit may occur.

In contrast, since the all-solid-state battery is a battery using a solid electrolyte, liquid leakage, dendrites do not occur, and the separator does not break. Therefore, there is no concern about ignition due to destruction of the separator, and it is attracting great attention in terms of safety, etc.

A typical all-solid-state battery is comprised of a solid battery body, such as an electrode active material or a solid electrolyte, encapsulated inside an exterior material serving as a casing. In this all-solid-state battery, as research on solid electrolytes progresses, the performance required for the exterior material is gradually becoming different from that of the exterior material for batteries using conventional liquid electrolytes, and the performance for all-solid-state batteries is gradually increasing. Various exterior materials have been proposed to meet these requirements.

The exterior material for an all-solid-state battery has a basic structure that includes a metal foil layer and a heat-sealing layer (sealant layer) laminated on the inside, and the solid-state battery body is encapsulated by heat-sealing the sealant layer.

For example, the exterior material for an all-solid-state battery shown in Patent Document 1 below has a protective film interposed between a metal foil layer and a sealant layer, and a sealant layer with high hydrogen sulfide gas permeability is used. In addition, the exterior material for an all-solid-state battery shown in Patent Document 2 has a high hydrogen sulfide gas permeability as a sealant layer. Additionally, the exterior material for an all-solid-state battery shown in Patent Document 3 is used as a sealant layer to absorb gas. Additionally, the exterior material for an all-solid-state battery shown in Patent Document 4 is composed of a vapor-deposited film layer laminated on the inner surface of a sealant layer.

Japanese Patent No. 6777276 Japanese Patent No. 6747636 Japanese Patent Laid-open No. 2020-187855 Japanese Patent Laid-open No. 2020-187835

However, in all-solid-state batteries as shown in Patent Documents 1 to 4, gases remaining in the casing (packaging material) cannot be replaced with electrolyte, so when encapsulating the solid battery body in the packaging material, it is performed under reduced pressure. No gas remains in the exterior material, and the exterior material is in close contact with the solid battery body. On the other hand, since the solid electrolyte does not have the same cushioning properties as the liquid electrolyte, if there is a foreign matter in the packaging material or a protruding part on the solid battery body, stress is concentrated on the part of the protruding part in close contact with the packaging material, and that part later becomes damaged. There is a problem that defective parts that occur, for example, defects such as damage to the exterior material, occur. In particular, since the probability of occurrence of defective parts increases in a high temperature environment where all-solid-state batteries have an advantage, the development of technology that can prevent the occurrence of defective parts even in high temperature environments, not limited to room temperature, is urgently desired.

Preferred embodiments of the present invention have been made in consideration of the above-mentioned and/or other problems in the related art. Preferred embodiments of the present invention are those that can significantly improve existing methods and/or devices.

The present invention was made in consideration of the above-described problems, and its purpose is to provide an exterior material for an all-solid-state battery and an all-solid-state battery that can prevent defects such as breakage from occurring even in a high temperature environment.

Other objects and advantages of the present invention will become apparent from the following preferred embodiments.

In order to solve the above problems, the present invention provides the following means.

[1] An exterior material for an all-solid-state battery for encapsulating a solid-state battery body, comprising a base layer, a metal foil layer laminated on the inner surface of the base layer, and a sealant layer laminated on the inner surface of the metal foil layer,

A heat-resistant gas barrier layer made of resin is provided between the metal foil layer and the sealant layer,

The heat-resistant gas barrier layer is an exterior material for an all-solid-state battery, characterized in that the Young's modulus at 90°C is 1 GPa or more in both MD and TD.

[2] The heat-resistant gas barrier layer is an exterior material for an all-solid-state battery according to the preceding paragraph 1, wherein the heat-resistant gas barrier layer has a tensile breaking strength of both MD and TD of 100 MPa or more at 90°C.

[3] The exterior material for an all-solid-state battery according to the preceding item 1 or 2, wherein the heat-resistant gas barrier layer has a tensile elongation at rupture of 50% to 200% in both MD and TD at 90°C.

[4] The exterior material for an all-solid-state battery according to any one of the preceding paragraphs 1 to 3, wherein the heat-resistant gas barrier layer is made of a resin with a melting point higher than that of the sealant layer by at least 10°C, and the thickness is set to 3 μm to 50 μm. .

[5] An all-solid-state battery, characterized in that the solid-state battery body is encapsulated in the exterior material for an all-solid-state battery according to any one of the preceding paragraphs 1 to 4.

According to the exterior material for an all-solid-state battery of invention [1], a heat-resistant gas barrier layer having a high Young's modulus at high temperature is interposed between the metal foil layer and the sealant layer, so the heat-resistant gas barrier layer is not limited to room temperature and even in a high temperature environment. Furthermore, it is possible to reliably prevent defects such as damage from occurring throughout the exterior material.

According to the exterior material for an all-solid-state battery of inventions [2] and [3], even if the exterior material expands and stretches due to an increase in internal pressure due to high temperature in a state in which the solid battery body is enclosed, damage to the exterior material can be more reliably prevented.

According to the exterior material for an all-solid-state battery of invention [4], a predetermined thickness can be secured while preventing melt and outflow of the heat-resistant gas barrier layer even by thermal bonding of the sealant layer, which has the effect of preventing the occurrence of defects by the heat-resistant gas barrier layer. can be obtained more reliably.

According to invention [5], since it specifies an all-solid-state battery using the exterior material of inventions [1] to [4], the above-mentioned effects can be obtained.

1 is a schematic cross-sectional view showing an all-solid-state battery according to an embodiment of the present invention.
Fig. 2 is a schematic cross-sectional view showing an exterior material used in an all-solid-state battery of the embodiment.

FIG. 1 is a schematic cross-sectional view showing an all-solid-state battery according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view showing the packaging material 1 used in the all-solid-state battery. As shown in both drawings, the exterior material 1 configured as the casing of the all-solid-state battery of this embodiment is made of a laminate such as a laminate sheet.

This exterior material 1 includes a base layer 11 disposed on the outermost side, a metal foil layer 12 laminated on the inner side of the base layer 11, and a heat-resistant gas barrier laminated on the inner side of the metal foil layer 12. It has a layer 21 and a sealant layer 13 laminated on the inner surface of the heat-resistant gas barrier layer 21, and in the present embodiment, between each layer 11 to 13 and 21 of the exterior material 1. is bonded through an adhesive (adhesive layer) using a dry lamination method or a heat lamination method. In other words, the exterior material 1 of this embodiment is a laminate composed of base material layer 11/adhesive layer/metal foil layer 12/adhesive layer/heat-resistant gas barrier layer 21/adhesive layer/sealant layer 13. It is composed by.

In this embodiment, as shown in FIG. 1, an all-solid-state battery is manufactured by encapsulating the solid-state battery body 5 to cover it with the exterior material 1 of the above-described configuration. That is, the two square-shaped exterior materials 1, 1 are overlapped top and bottom through the solid battery body 5, and the sealant layers 13, 13 of the outer peripheral edges of the two (pair of) exterior materials 1, 1 are formed. An all-solid-state battery in which the solid-state battery body (5) is housed in a bag-shaped casing made of the exterior materials (1, 1) by joining and integrating them in an airtight state (encapsulated state) by thermal bonding (heat sealing). is produced.

In the all-solid-state battery of this embodiment, although not shown, a tab lead is provided for extracting electricity. One end (inner side) of this tab lead is adhesively fixed to the solid battery body 5, the middle part passes between the outer peripheral edges of the two exterior bodies 1, 1, and the other end side (outer end side) is drawn out. It is arranged as much as possible.

In addition, in the present embodiment, the casing is formed by bonding two planar exterior materials 1, 1 together, but the casing is not limited to this, and in the present invention, at least one of the two exterior materials 1, 1 is molded into a tray shape in advance. Then, one tray-shaped exterior material may be bonded to the other tray-shaped or flat exterior material to form a casing.

Below, the detailed configuration of the exterior material 1 of the all-solid-state battery of this embodiment will be described.

The base material layer 11 of the exterior material 1 is made of a heat-resistant resin film with a thickness of 5 μm to 50 μm. As the resin constituting this base layer 11, polyamide, polyester (PET, PBT, PEN), polyolefin (PE, PP), etc. can be suitably used.

The thickness of the metal foil layer 12 is set to 5 μm to 120 μm, and has a function of blocking the intrusion of oxygen and moisture from the surface (outer surface) side. As this metal foil layer 12, aluminum foil, SUS foil (stainless steel foil), copper foil, nickel foil, etc. can be suitably used. Additionally, in this embodiment, the terms “aluminum,” “copper,” and “nickel” are used to include their alloys.

Additionally, if plating treatment or the like is performed on the metal foil layer 12, the risk of pinholes occurring is reduced, and the function of blocking the intrusion of oxygen or moisture can be further improved.

In addition, if the metal foil layer 12 is subjected to chemical conversion treatment such as chromate treatment, corrosion resistance is further improved, and defects such as defects can be more reliably prevented from occurring, and adhesion to the resin can be improved. This can further improve durability.

The sealant layer 13 has a thickness set to 10 μm to 100 μm and is made of a film of heat-sealable (heat-sealable) resin. Resins constituting this sealant layer 13 include polyethylene (LLDPE, LDPE, HDPE), polyolefins such as polypropylene, olefin-based copolymers, and acid-modified products and ionomers thereof, for example. For example, non-stretched polypropylene (CPP, IPP) can be used appropriately.

As the sealant layer 13, considering that electricity is extracted using a tab lead, that is, considering sealing and adhesiveness with the tab lead, polypropylene-based resin (non-stretched polypropylene film (CPP) , IPP)) is preferable.

The heat-resistant gas barrier layer 21 is made of a resin film having heat resistance and insulating properties. Resins constituting this heat-resistant gas barrier layer 21 include polyamides (6-nylon, 66-nylon, MXD nylon, etc.), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate ( It is preferable to use PEN), cellophane, polyvinylidene chloride (PVDC), etc.

In this embodiment, the resin film constituting the heat-resistant gas barrier layer 21 has a Young's modulus at 90°C of 1 GPa or more for both MD, which is the flow direction, and TD, which is the direction orthogonal to MD, and preferably 5 GPa or more. It is desirable. In other words, by adopting this configuration, a predetermined hardness can be secured in the heat-resistant gas barrier layer 21 and, by extension, the exterior material 1 even in a high-temperature environment, not limited to room temperature, thereby preventing the occurrence of defective parts such as breakage. can be prevented.

Additionally, in this embodiment, the Young's modulus of the heat-resistant gas barrier layer 21 at room temperature (25°C) is 1.5 GPa or more.

In addition, in this embodiment, it is preferable that the heat-resistant gas barrier layer 21 has a tensile breaking strength of 100 MPa or more and 400 MPa or less in both MD and TD at 90°C. In other words, when this configuration is adopted, even if the internal pressure increases due to expansion of the solid battery main body 5 under high temperature and the packaging material 1 expands, damage to the packaging material 1 can be reliably prevented.

In addition, in this embodiment, it is preferable that the heat-resistant gas barrier layer 21 adopts a configuration in which the tensile elongation at rupture at 90°C is 50% to 200% in both MD and TD. That is, in the case of this configuration, even if the exterior material 1 expands and elongates due to an increase in internal pressure under high temperature, damage to the exterior material 1 can be more reliably prevented.

In addition, in this embodiment, the tensile breaking strength of the heat-resistant gas barrier layer 21 at room temperature (25°C) is 150 MPa, and the tensile elongation at breaking is 50% to 150%.

In this embodiment, the resin constituting the heat-resistant gas barrier layer 21 preferably has a predetermined hydrogen sulfide (H ₂ S) gas permeability. Specifically, the heat-resistant gas barrier layer 21 is preferably made of a resin with a hydrogen sulfide gas permeability of 15 {cc·mm/(m2·D·MPa)} or less as measured in accordance with JIS K7126-1. It is preferably composed of a resin of 10{cc·mm/(㎡·D·MPa)} or less, and more preferably of a resin of 4.0{cc·mm/(㎡·D·MPa)} or less. It's good to do it. That is, when the hydrogen sulfide gas permeability of the heat-resistant gas barrier layer 21 is set to the above-mentioned specific value or less, when hydrogen sulfide gas is generated by the reaction between the solid electrolyte material and moisture in the external air, the hydrogen sulfide gas is generated by the heat-resistant gas barrier layer 21. It can prevent gas from leaking to the outside. In other words, if the hydrogen sulfide gas permeability of the heat-resistant gas barrier layer 21 is too large, the generated hydrogen sulfide gas may pass through the exterior material 1 (heat-resistant gas barrier layer 21) and leak to the outside, which is not desirable. not.

Also, for reference, “D” included in the unit of hydrogen sulfide gas permeability corresponds to “Day (24h).”

In addition, in this embodiment, the resin constituting the heat-resistant gas barrier layer 21 has a water vapor gas permeability of 50 (g/m2/day) measured in accordance with JIS K7129-1 (humidity sensor method 40°C 90% Rh). It is better to set it below, more preferably below 40 (g/m2/day), and even more preferably below 20 (g/m2/day). In other words, hydrogen sulfide gas is generated when external moisture penetrates the exterior material 1 and reacts with the solid electrolyte material. When the water vapor gas permeability of the heat-resistant gas barrier layer 21 is set to the above-mentioned specific value or less, the heat-resistant gas barrier layer 21 reacts with the solid electrolyte material. In addition to being able to prevent the intrusion of moisture by the gas barrier layer 21, the gas barrier function of the metal foil layer 12 is also compatible with each other, so that the intrusion of moisture can be more reliably prevented, thereby ensuring the generation of hydrogen sulfide gas itself. This can be prevented, and furthermore, it is possible to more reliably prevent hydrogen sulfide gas from leaking to the outside.

In this embodiment, the thickness of the heat-resistant gas barrier layer 21 is preferably set to 3 μm to 50 μm, and more preferably set to 10 μm to 40 μm. That is, when the thickness of the heat-resistant gas barrier layer 21 is set to this range, the effect of preventing the occurrence of defective parts described above can be reliably obtained, and even if the sealant layer 13 melts and flows out due to thermal bonding, The effect of preventing the occurrence of defective parts by the heat-resistant gas barrier layer 21 can be maintained. In other words, if the heat-resistant gas barrier layer 21 is too thin, there is a risk that the defect generation effect may not be obtained, which is not preferable. Conversely, if the heat-resistant gas barrier layer 21 is too thick, not only can the exterior material 1 not be made thinner, but the effect of making it thicker than necessary is not fully obtained, which is not desirable.

In this embodiment, it is preferable to use a resin film as the heat-resistant gas barrier layer 21. That is, because the entire film becomes a barrier layer, unlike vapor-deposited films, barrier cracks do not occur, and barrier properties can be improved.

Additionally, as the resin film constituting the heat-resistant gas barrier layer 21, an unstretched film or a slightly stretched film can be used, and it is especially preferable to use an unstretched film. That is, when a non-stretched film is used, formability and gas barrier properties can be further improved.

Additionally, in this embodiment, it is preferable to employ a resin constituting the heat-resistant gas barrier layer 21 that has a melting point of 10°C or more higher than that of the resin constituting the sealant layer 13. That is, when the heat-resistant gas barrier layer 21 is set to a high melting point, even if the sealant layer 13 is melted when heat-sealing the exterior material 1, it is impossible to prevent the melt and outflow of the heat-resistant gas barrier layer 21. Therefore, the effect of preventing the occurrence of defective parts by the heat-resistant gas barrier layer 21 can be reliably obtained.

Meanwhile, in the present embodiment, the adhesive (adhesive layer) for bonding the layers 11 to 13, 21 of the exterior material 1 is a curing type such as an energy ray (UV, X-ray, etc.) curing type. Among them, urethane-based adhesives, olefin-based adhesives, acrylic-based adhesives, epoxy-based adhesives, etc. can be appropriately used. Additionally, in this embodiment, the thickness of the adhesive layer is preferably set to 2 μm to 5 μm.

As described above, according to the all-solid-state battery of this embodiment, since the above-described unique heat-resistant gas barrier layer 21 is interposed between the metal foil layer 12 and the sealant layer 13 in the exterior material 1, the temperature is limited to room temperature. Even in a high-temperature environment, it is possible to reliably prevent defective parts such as damage from occurring in the heat-resistant gas barrier layer 21 and, by extension, the exterior material 1, and provides an all-solid-state battery product with excellent operational reliability, especially in a high-temperature environment. can do.

Example

[Table 1]

<Example 1>

1. Production of exterior materials

After applying a chemical treatment solution consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water, and alcohol to both sides of an aluminum foil (A8021-O) with a thickness of 40 μm as the metal foil layer 12, Drying was performed at 180°C to form a chemical conversion film. The chromium adhesion amount of this chemical conversion film was 10 mg/m2 per side.

Next, a two-component curing type urethane-based adhesive (3 μm) is applied to one surface (outer surface) of the chemically treated aluminum foil (metal foil layer 12) to form a biaxial layer with a thickness of 15 μm as a base material layer 11. Stretched 6 nylon (ONy) film was dry laminated (laminated).

As shown in Table 1, as the heat-resistant gas barrier resin layer 21, a 9 μm thick PET film was applied to the other side (inner surface) of the dry laminated aluminum foil with a two-component curing type urethane-based adhesive (3 μm). ) was met through.

Next, as shown in Table 1, as the sealant layer 13, a 40 ㎛ thick CPP film containing a lubricant (erucic acid amide, etc.) was laminated through a two-component curing type urethane adhesive (3 ㎛) to the dry laminate. The inner surface of the later PET film (heat-resistant gas barrier layer 21) is overlapped, sandwiched between a rubber nip roll and a laminate roll heated to 100°C, and dry laminated by pressing, thereby forming the exterior material 1. got a sieve

Next, this laminate was wound on a roll shaft and then aged at 40°C for 10 days to obtain an exterior material sample of Example 1.

2. Measurement of Young’s modulus, tensile strength at break and tensile elongation at break

Regarding the PET film (heat-resistant gas barrier layer 21) used when producing the exterior material sample of Example 1, Young's modulus, tensile strength at break, and tensile elongation at break at 90°C for both MD and TD in accordance with JIS K7127-1999. were measured respectively. That is, the PET film for the heat-resistant gas barrier layer was cut to a size of 15 mm in width A tensile test was performed at a speed of 200 mm/min to measure Young's modulus (MPa), tensile strength at break (MPa), and tensile elongation at break (%). As shown in Table 1, in the PET film for the heat-resistant gas barrier layer of Example 1, the Young's modulus is 3.6 GPa in MD and 3.2 GPa in TD, and the tensile breaking strength is 190 MPa in MD and 210 MPa in TD, The tensile elongation at break is 120% in MD and 110% in TD.

3. Evaluation of high temperature stone magnetism

The puncture strength of the exterior material sample of Example 1 was measured in an atmosphere of 90°C in accordance with JIS Z1707:1997. The measurement method (puncture strength test method) is as follows.

An exterior material sample of a predetermined size was fixed as a test piece, a semicircular needle with a diameter of 1.0 mm and a tip radius of 0.5 mm was pierced at a speed of 50 ± 5 mm per minute, and the maximum stress until the needle penetrated was measured. . The number of test pieces was 5, and the average value was taken as the strength. The results are also shown in Table 1.

4. Evaluation of formability

The exterior material sample of Example 1 was cut into a size of 100 mm x 100 mm to obtain a sample for evaluating formability. For this sample for moldability evaluation, a deep drawing molding test was performed using a mold for deep drawing molding attached to a 25t press machine and changing the molding height (drawing depth) in 0.5 mm units.

Also, if the desired moldability is obtained even when the molding height is 7 mm or more, it is evaluated as “◎”. If the mold height is 7 mm or more, the desired moldability is not obtained, but the moldability is determined in the range of 5 mm or more and less than 7 mm. When this was obtained, it was evaluated as “○”, and when the desired formability was not obtained at less than 5 mm, it was evaluated as “×”. The results are also shown in Table 1.

5. Measurement of yarn strength

After cutting out two pieces of the exterior material sample of Example 1 with a size of 15 mm in width Using (TP-701-A), heat sealing (thermal bonding) was performed by heating on one side under the conditions of heat seal temperature: 200°C, actual pressure: 0.2 MPa (gauge display pressure), and actual time: 2 seconds. A sample for evaluating the yarn strength of Example 1 was obtained.

Regarding this sample for yarn strength evaluation, a Strograph (AGS-5kNX) manufactured by Shimadzu Access was used in accordance with JIS Z0238-1998, and the sample for yarn strength evaluation was measured at a tensile rate of 100 mm/m between the inner sealant layers of the yarn portion. The peeling strength when peeled in a T shape was measured, and this was taken as the thread strength (N/15 mm width). The results are also shown in Table 1.

<Example 2>

The heat-resistant gas barrier layer 21 has a Young's modulus of MD: 1.5 GPa and TD: 1.2 GPa, a tensile strength at break of MD: 210 MPa and TD: 240 MPa, and a tensile elongation at break of MD: 140% and TD: 120%. A sample of Example 2 was produced in the same manner as Example 1 above, except that an axially stretched 6-nylon film (ONY-6 film) was used, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Example 3>

A sample of Example 3 was produced in the same manner as Example 2 except that a film with a thickness of 15 μm was used as the heat-resistant gas barrier layer 21, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Example 4>

A sample of Example 4 was produced in the same manner as Example 2 except that a film with a thickness of 25 μm was used as the heat-resistant gas barrier layer 21, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Example 5>

The heat-resistant gas barrier layer 21 is PET with Young's modulus of MD: 3.4 GPa, TD: 3.1 GPa, tensile strength at break of MD: 200 MPa, TD: 220 MPa, and tensile elongation at break of MD: 130% and TD: 125%. A sample of Example 5 was produced in the same manner as Example 1 except that a film was used, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

Additionally, in Example 5, the Young's modulus, tensile strength at break, and tensile elongation at break of the PET film were different from Example 1 by adjusting the conditions at the time of film production and changing the degree of crystallinity.

<Example 6>

The heat-resistant gas barrier layer 21 has a Young's modulus of MD: 1.1 GPa, TD: 1.6 GPa, a tensile strength at break of MD: 90 MPa, TD: 160 MPa, and a tensile elongation at break of MD: 140% and TD: 80%. A sample of Example 6 was produced in the same manner as Example 1 above except that an axially stretched polypropylene film (OPP film) was used, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Example 7>

A sample of Example 7 was produced in the same manner as Example 1 except that a CPP film with a thickness of 10 μm was used as the sealant layer 13, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Example 8>

A sample of Example 8 was produced in the same manner as Example 1 except that a CPP film with a thickness of 100 μm was used as the sealant layer 13, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Example 9>

The same procedure as Example 1 was carried out except that a polyvinylidene chloride (PVDC) film with a thickness of 10 μm was used as the heat-resistant gas barrier layer 21, and a CPP film with a thickness of 30 μm was used as the sealant layer 13. The sample of Example 9 was produced and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Example 10>

A sample of Example 10 was produced in the same manner as Example 9 above except that a PVDC film with a thickness of 15 μm was used as the heat-resistant gas barrier layer 21, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Example 11>

A sample of Example 11 was produced in the same manner as Example 9 above except that a PVDC film with a thickness of 25 μm was used as the heat-resistant gas barrier layer 21, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Example 12>

A sample of Example 12 was produced in the same manner as Example 9 above except that PVDC was coated to a thickness of 2 μm on the outer surface (inner surface) of the aluminum foil for the metal foil layer to form a heat-resistant gas barrier layer 21, and the same measurements were made. (Evaluation) was performed. The results are also shown in Table 1.

<Example 13>

A sample of Example 13 was produced in the same manner as Example 9 above except that a PVDC film with a thickness of 50 μm was used as the heat-resistant gas barrier layer 21, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

<Comparative example 1>

As the heat-resistant gas barrier layer 21, OPP has a Young's modulus of 0.9 GPa in MD, 1.5 GPa in TD, a tensile strength at break of 80 MPa in MD, 150 MPa in TD, and an elongation at break of 150% in MD and 80% in TD. A sample of Comparative Example 1 was produced in the same manner as in Example 6 except for using a film, and the same measurement (evaluation) was performed. The results are also shown in Table 1.

Additionally, in Comparative Example 1, the Young's modulus, tensile strength at break, and tensile elongation at break of the OPP film were different from Example 6 by adjusting the conditions at the time of film production and changing the degree of crystallinity.

<Overall review>

As is clear from Table 1, the exterior material samples of Examples 1 to 13 related to the present invention are excellent in magnetic resistance at 90°C, and it is thought that defective parts such as breakage are unlikely to occur in a high temperature environment. In particular, the exterior material sample of Example 13 has The stone magnetic properties were excellent.

On the other hand, the exterior material sample of Comparative Example 1, which deviates from the gist of the present invention, is inferior to the magnetic resistance at 90°C, and it is thought that defective parts such as breakage are more likely to occur in a high temperature environment compared to those of Examples 1 to 8. .

This application accompanies the priority claim of Japanese Patent Application No. 2021-132728, filed on August 17, 2021, and the disclosure content constitutes a part of this application as is.

The terms and expressions used herein are for the purpose of description and are not to be construed as limiting, nor do they exclude any equivalents of the features shown and stated herein, and do not exclude any equivalents of the features shown and stated herein, and are intended to cover a variety of issues within the claimed scope of the invention. It should be recognized that transformation is also allowed.

The exterior material for an all-solid-state battery of the present invention can be suitably used as a material for a casing for housing the solid-state battery body.

1: Exterior material
11: Base layer
12: Metal foil layer
13: Sealant layer
21: Heat-resistant gas barrier layer
5: Solid battery body

Claims (5)

An exterior material for an all-solid-state battery for encapsulating a solid-state battery body, comprising a base material layer, a metal foil layer laminated on the inner surface of the base layer, and a sealant layer laminated on the inner surface of the metal foil layer,
A heat-resistant gas barrier layer made of resin is provided between the metal foil layer and the sealant layer,
The heat-resistant gas barrier layer is an exterior material for an all-solid-state battery, characterized in that the Young's modulus at 90°C is 1 GPa or more in both MD and TD. According to paragraph 1,
The heat-resistant gas barrier layer is an exterior material for an all-solid-state battery, characterized in that the tensile breaking strength at 90°C is 100 MPa or more in both MD and TD. According to claim 1 or 2,
The heat-resistant gas barrier layer is an exterior material for an all-solid-state battery, characterized in that the tensile elongation at rupture at 90°C is 50% to 200% in both MD and TD. According to any one of claims 1 to 3,
An exterior material for an all-solid-state battery, wherein the heat-resistant gas barrier layer is made of a resin with a melting point that is at least 10°C higher than that of the sealant layer, and the thickness is set to 3 μm to 50 μm. An all-solid-state battery, characterized in that the solid-state battery main body is encapsulated in the exterior material for an all-solid-state battery according to any one of claims 1 to 4.

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