Exterior material for all-solid-state battery and all-solid-state battery

Abstract

To provide a sheath material for an all-solid battery having good insulation properties even at a high temperature.SOLUTION: Provided is a sheath material for an all-solid battery for sealing a solid-state battery main body 5 that comprises: a base material layer 11; a metal foil layer 12 laminated at an inner surface side of the base material layer 11; and a sealant layer 13 laminated at an inner surface side of the metal foil layer 12. A heat-proof gas barrier layer 21 is provided between the metal foil layer 12 and the sealant layer 13. The heat-proof gas barrier layer 21 is composed of an insulative resin having a melting point higher than that of the sealant layer 13 by 20°C or more. The heat-proof gas barrier layer 21 has a dielectric breakdown voltage of 18 kV / mm or more and has a thickness of 3 to 50 μm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an exterior packaging material for an all-solid-state battery used as a high-power battery such as an in-vehicle battery, a battery for portable devices such as a mobile electronic device, a battery for storing regenerative energy, etc., and the all-solid-state battery. [Background technology]

[0002] Conventionally widely used lithium-ion secondary batteries use a liquid electrolyte, which can lead to the destruction of the separator due to leakage or the formation of dendrites, and in some cases, to the risk of fire or other problems caused by a short circuit.

[0003] In contrast, all-solid-state batteries use a solid electrolyte, so they do not leak or develop dendrites, and the separator is not damaged. Therefore, there is no risk of fire caused by separator damage, and they are attracting much attention from the perspective of safety.

[0004] A typical all-solid-state battery is configured by sealing a solid-state battery body, such as an electrode active material and a solid electrolyte, inside an exterior material serving as a casing. As research into solid electrolytes in all-solid-state batteries progresses, it has gradually become apparent that the performance required of the exterior material differs from that of exterior materials for batteries using conventional liquid electrolytes, and various exterior materials have been proposed to satisfy the performance requirements for all-solid-state batteries.

[0005] The basic structure of an exterior material for an all-solid-state battery includes a metal foil layer and a heat-sealing layer (sealant layer) laminated inside the metal foil layer, and the solid-state battery body is encapsulated by heat-sealing the sealant layer.

[0006] For example, the all-solid-state battery packaging material disclosed in Patent Document 1 below has a protective film interposed between a metal foil layer and a sealant layer, and uses a sealant layer with high hydrogen sulfide gas permeability. Furthermore, the all-solid-state battery packaging material disclosed in Patent Document 2 uses a sealant layer with high hydrogen sulfide gas permeability. Furthermore, the all-solid-state battery packaging material disclosed in Patent Document 3 uses a sealant layer that absorbs gas. Furthermore, the all-solid-state battery packaging material disclosed in Patent Document 4 is configured by laminating a vapor-deposited film layer on the inner surface of a sealant layer. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6777276 [Patent Document 2] Patent No. 6747636 [Patent Document 3] Patent Publication No. 2020-187855 [Patent Document 4] Patent Publication No. 2020-187835 Summary of the Invention [Problem to be solved by the invention]

[0008] However, like conventional batteries, all-solid-state batteries are likely to be used in high-temperature environments, but the all-solid-state batteries using the exterior materials shown in Patent Documents 1 to 4 do not fully consider the insulating properties in high-temperature environments, and there are concerns that the insulating properties may decrease in high-temperature environments.

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an exterior packaging material for an all-solid-state battery and an all-solid-state battery that can ensure sufficient insulation even in a high-temperature environment. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention comprises the following means.

[0011] [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 side of the base layer; and a sealant layer laminated on the inner surface side of the metal foil layer, a heat-resistant gas barrier layer is provided between the metal foil layer and the sealant layer; the heat-resistant gas barrier layer is made of an insulating resin having a melting point 20°C or more higher than that of the sealant layer, The heat-resistant gas barrier layer has a breakdown voltage of 18 kV / mm or more and a thickness of 3 μm to 50 μm.

[0012] [2] The packaging material for an all-solid-state battery according to item 1, wherein the resin constituting the heat-resistant gas barrier layer has a hot water shrinkage rate of 2% to 10%.

[0013] [3] The packaging material for an all-solid-state battery according to the above item 1 or 2, wherein the resin constituting the heat-resistant gas barrier layer is polyamide.

[0014] [4] A vapor deposition layer is formed between the gas barrier layer and the sealant layer, 4. The exterior packaging material for an all-solid-state battery according to any one of items 1 to 3 above, wherein the vapor deposition layer is composed of at least one of a metal, a metal oxide, and a metal fluoride.

[0015] [5] An all-solid-state battery, characterized in that a solid-state battery body is enclosed in the packaging material for an all-solid-state battery according to any one of items 1 to 4 above. [Effects of the Invention]

[0016] According to the all-solid-state battery packaging material of invention [1], a heat-resistant gas barrier layer having insulating properties is interposed between the metal foil layer and the sealant layer, so that sufficient insulation can be ensured even in a high-temperature environment.

[0017] According to the all-solid-state battery packaging material of the invention [2], the hot water shrinkage rate of the heat-resistant gas barrier layer is specified, so that it is possible to improve formability while ensuring high insulation properties.

[0018] According to the all-solid-state battery packaging material of the invention [3], a general-purpose polyamide resin is used as the heat-resistant gas barrier layer, so that it can be produced simply and efficiently.

[0019] According to the all-solid-state battery packaging material of the invention [4], a vapor-deposited film is formed between the heat-resistant gas barrier layer and the sealant layer, so that the gas barrier properties and insulating properties can be further improved.

[0020] According to the invention [5], an all-solid-state battery using the packaging material of the inventions [1] to [4] above is specified, and therefore the same effects as those described above can be obtained. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an all-solid-state battery according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an exterior material used in the all-solid-state battery of the embodiment. [Figure 3] FIG. 3 is a plan view showing a schematic diagram of the insulating property evaluation sample. [Figure 4] FIG. 4 is a cross-sectional view schematically showing the insulation evaluation sample of FIG. 3, and corresponds to the cross section taken along line IV-IV of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] 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 an exterior material 1 used in the all-solid-state battery. As shown in both figures, the exterior material 1, which serves as a casing for the all-solid-state battery according to this embodiment, is made of a laminate such as a laminate sheet.

[0023] This packaging material 1 includes a base material layer 11 disposed on the outermost side, a metal foil layer 12 laminated on the inner side of the base material layer 11, a heat-resistant gas barrier layer 21 laminated on the inner side of the metal foil layer 12, and a sealant layer 13 laminated on the inner side of the heat-resistant gas barrier layer 21. In this embodiment, the layers 11 to 13, 21 of the packaging material 1 are bonded together via adhesives (adhesive layers) by dry lamination. In other words, the packaging material 1 of this embodiment is composed of a laminate consisting of base material layer 11 / adhesive layer / metal foil layer 12 / adhesive layer / heat-resistant gas barrier layer 21 / adhesive layer / sealant layer 13.

[0024] 1, in this embodiment, an all-solid-state battery is produced by enclosing a solid-state battery body 5 in such a manner that it is covered with the exterior material 1 having the above-described configuration. That is, two rectangular exterior materials 1, 1 are stacked one on top of the other with the solid-state battery body 5 interposed therebetween, and the sealant layers 13, 13 at the outer peripheries of the two (pair of) exterior materials 1, 1 are joined together in an airtight (sealed) state by thermal bonding (heat sealing), thereby producing 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.

[0025] Although not shown, the all-solid-state battery of this embodiment is provided with a tab lead for taking out electricity. One end (inner end) of this tab lead is adhesively fixed to the solid-state battery body 5, and the middle part passes between the outer peripheral edges of the two exterior bodies 1, 1, and the other end (outer end) is arranged so as to be drawn out to the outside.

[0026] In this embodiment, two planar exterior materials 1, 1 are bonded together to form the casing, but this is not limited to this. In the present invention, at least one of the two exterior materials may be formed into a tray shape in advance, and the tray-shaped exterior material may be bonded to the other tray-shaped or planar exterior material to form the casing.

[0027] The detailed configuration of the exterior packaging material 1 of the all-solid-state battery of this embodiment will be described below.

[0028] The base material layer 11 of the packaging material 1 is made of a heat-resistant resin film having a thickness of 5 μm to 50 μm. Suitable resins that can be used to make this base material layer 11 include oriented polyamide, oriented polyester (PET, PBT, PEN), and oriented polyolefin (PE, PP).

[0029] The metal foil layer 12 has a thickness set to 5 μm to 120 μm and has the function of blocking the penetration of oxygen and moisture from the surface (outer surface) side. Aluminum foil, SUS foil (stainless steel foil), copper foil, nickel foil, etc. can be suitably used as this metal foil layer 12. In this embodiment, the terms "aluminum," "copper," and "nickel" are used to mean alloys thereof.

[0030] Furthermore, if the metal foil layer 12 is subjected to a plating process or the like, the risk of pinholes occurring is reduced, and the function of blocking the intrusion of oxygen and moisture can be further improved.

[0031] Furthermore, if the metal foil layer 12 is subjected to a chemical conversion treatment such as chromate treatment, the corrosion resistance is further improved, so that defects such as chipping can be more reliably prevented, and the adhesion to the resin can be improved, thereby further improving durability.

[0032] The sealant layer 13 has a thickness set to 10 μm to 100 μm and is made of a film of a heat-adhesive (heat-fusible) resin. Suitable resins for the sealant layer 13 include polyethylene (LLDPE, LDPE, HDPE), polyolefins such as polypropylene, olefin copolymers, acid-modified products thereof, and ionomers, such as unstretched polypropylene (CPP, IPP).

[0033] Considering that electricity is extracted using a tab lead, that is, in consideration of sealing and adhesive properties with the tab lead, it is preferable to use a polypropylene resin (non-oriented polypropylene film (CPP, IPP)) as the sealant layer 13.

[0034] The heat-resistant gas barrier layer 21 is made of a heat-resistant and insulating resin film. The resin that makes up the heat-resistant gas barrier layer 21 is preferably polyamide (PA6, PA66, MXD, etc.), polyester (PET, PBT, PEN, etc.), cellophane, polyvinylidene chloride, etc.

[0035] The heat-resistant gas barrier layer 21 of this embodiment has good insulating properties, and maintains good insulating properties even after the solid battery body 5 is encapsulated (sealed) by thermal bonding with the exterior material 1 of this embodiment.

[0036] In this embodiment, the resin film constituting the heat-resistant gas barrier layer 21 has a volume resistivity of 1×10 at room temperature (25° C.). 10 (Ω·m) or more is preferable, and in particular, a volume resistivity of 1×10 at 100°C is preferable. 5 (Ω·m) or more is preferable. For reference, the volume resistivity of polyamides such as nylon is 1×10 at room temperature. 11 (Ω m), and at 100°C it is 1×10 7 (Ω·m).

[0037] In this embodiment, the resin constituting the heat-resistant gas barrier layer 21 preferably has a predetermined hydrogen sulfide (H2S) gas permeability. Specifically, the heat-resistant gas barrier layer 21 has a hydrogen sulfide gas permeability of 30 cc·mm / (m2) as measured in accordance with JIS K7126-1. 2It is preferable that the heat-resistant gas barrier layer 21 be made of a resin having a resistance of {·D·MPa} or less. That is, if the hydrogen sulfide gas permeability of the heat-resistant gas barrier layer 21 is set to the above-mentioned predetermined value or less, when hydrogen sulfide gas is generated as a result of a reaction between the solid electrolyte material and moisture in the outside air, the heat-resistant gas barrier layer 21 can prevent the hydrogen sulfide 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 high, there is a risk that the generated hydrogen sulfide gas will pass through the exterior material 1 (heat-resistant gas barrier layer 21) and leak to the outside, which is not preferable.

[0038] For reference, the "D" included in the unit of hydrogen sulfide gas permeability corresponds to "Day (24h)."

[0039] Furthermore, in this embodiment, the resin that constitutes the heat-resistant gas barrier layer 21 must have a melting point that is at least 20° C. higher than that of the resin that constitutes the sealant layer 13. In other words, if the heat-resistant gas barrier layer 21 has a high melting point, even if the sealant layer 13 melts when the packaging material 1 is thermally bonded, the heat-resistant gas barrier layer 21 can be prevented from melting and flowing out, and the gas permeation suppression effect and insulating properties of the heat-resistant gas barrier layer 21 can be reliably obtained.

[0040] Furthermore, in this embodiment, the heat-resistant gas barrier layer 21 needs to have a breakdown voltage of 18 kV / mm or more. That is, if the breakdown voltage of the heat-resistant gas barrier layer 21 is equal to or greater than a specific value, sufficient insulation can be reliably ensured. In other words, if the breakdown voltage of the heat-resistant gas barrier layer 21 is too low, sufficient insulation may not be ensured.

[0041] Furthermore, in this embodiment, the thickness of the heat-resistant gas barrier layer 21 needs to be set to 3 μm to 50 μm. That is, by setting the thickness of the heat-resistant gas barrier layer 21 within this range, the above-mentioned hydrogen sulfide gas permeation suppression effect can be reliably obtained, and even if the sealant layer 13 melts and flows out due to thermal adhesion, the heat-resistant gas barrier layer 21 can reliably ensure insulation. In other words, if the heat-resistant gas barrier layer 21 is too thin, there is a risk that the gas permeation suppression effect and insulation property cannot be ensured, which is undesirable. Conversely, if the heat-resistant gas barrier layer 21 is too thick, not only will it be impossible to reduce the thickness of the packaging material 1, but the full effect of making the layer thicker than necessary will also be undesirable.

[0042] In this embodiment, the hot water shrinkage rate of the heat-resistant gas barrier layer 21 is preferably set to 2% to 10%. That is, when this configuration is adopted, the formability of the heat-resistant gas barrier layer 21, and therefore the exterior packaging material 1, is improved, and high insulating properties can be maintained even after the solid battery body 5 is encapsulated in the exterior packaging material 1 by thermal bonding. In other words, if the hot water shrinkage rate of the heat-resistant gas barrier layer 21 deviates from the above-mentioned specific range, there is a risk that good insulating properties cannot be ensured, which is not preferable.

[0043] In this embodiment, the hot water shrinkage of the heat-resistant gas barrier layer 21 is the rate of dimensional change in the stretching direction of a resin film test piece (10 cm × 10 cm) that constitutes the heat-resistant gas barrier layer 21 before and after immersion in hot water at 95°C for 30 minutes. In this embodiment, the hot water shrinkage can be calculated using the following formula, where "X" is the dimension in the stretching direction before immersion treatment and "Y" is the dimension in the stretching direction after immersion treatment.

[0044] Hot water shrinkage rate (%) = {(XY) / X} x 100 On the other hand, in this embodiment, the adhesive (adhesive layer) for bonding the layers 11 to 13, 21 of the exterior material 1 can be a curing type such as a two-component curing type or a UV (energy ray) curing type, and among these, urethane-based adhesives, olefin-based adhesives, acrylic-based adhesives, epoxy-based adhesives, etc. can be preferably used.

[0045] In this embodiment, it is also preferable to form a vapor-deposited film (vapor-deposited layer) between the heat-resistant gas barrier layer 21 and the sealant layer 13. That is, an adhesive is provided between the heat-resistant gas barrier layer 21 and the sealant layer 13, and it is preferable to form a vapor-deposited film on at least one of the surface (inner surface) of the heat-resistant gas barrier layer 21 facing the adhesive layer (sealant layer 13) and the surface (outer surface) of the sealant layer 13 facing the adhesive layer (heat-resistant gas barrier layer 21).

[0046] In the present embodiment, by forming a vapor deposition film, the gas barrier properties can be further improved, and leakage of hydrogen sulfide gas can be more reliably prevented. Furthermore, by preventing gas leakage, the exterior material 1 (casing) of the all-solid-state battery expands, thereby thinning the heat-resistant gas barrier layer 21 and making it less likely for insulation breakdown to occur, thereby further improving insulation properties.

[0047] The vapor-deposited film is preferably made of at least one of metals such as aluminum, titanium, and silicone; metal oxides such as alumina, silica, and zinc oxide; and metal fluorides such as aluminum fluoride and magnesium fluoride.

[0048] Furthermore, it is preferable that the thickness of the vapor deposition layer is set to 50 Å to 10,000 Å (5 nm to 1,000 nm (0.005 μm to 1 μm)). That is, by setting the thickness within this range, good gas permeation suppression and insulating properties can be more reliably ensured.

[0049] As described above, according to the all-solid-state battery of this embodiment, the above-mentioned specific heat-resistant gas barrier layer 21 is interposed between the metal foil layer 12 and the sealant layer 13 in the exterior packaging material 1, so that good insulation can be reliably ensured even in a high-temperature environment. [Example]

[0050] [Table 1]

[0051] Example 1 1. Fabrication of exterior materials A chemical conversion treatment solution consisting of phosphoric acid, polyacrylic acid (acrylic resin), a chromium (III) salt compound, water, and alcohol was applied to both sides of a 40 μm thick aluminum foil (A8021-O) serving as the metal foil layer 12, and then dried at 180°C to form a chemical conversion coating. The chromium deposition amount of this chemical conversion coating was 10 mg / m per side. 2 It was.

[0052] Next, a 15 μm thick biaxially oriented 6 nylon (O-Ny) film was dry laminated (attached) to one side (outer side) of the above-mentioned chemically treated aluminum foil (metal foil layer 12) via a two-component curing urethane adhesive (3 μm) as the base layer 11.

[0053] Next, a PA6 (6-nylon) stretched film (O-Ny film) with a thickness of 9 μm, a melting point of 225°C, a breakdown voltage of 19 kV / mm, and a hot water shrinkage of 5% was prepared as the heat-resistant gas barrier layer 21, and a 20 nm-thick vapor-deposited aluminum film was formed on one side thereof, as shown in Table 1. The non-vapor-deposited side of this O-Ny film with the vapor-deposited film was attached to the other side (inner surface) of the above-mentioned dry-laminated aluminum foil via a two-component curing urethane adhesive (3 μm).

[0054] Next, as shown in Table 1, a CPP film containing a lubricant (such as erucic acid amide) and having a thickness of 20 μm and a melting point of 150°C was superimposed on the vapor deposition surface (inner surface) of the dry-laminated O-Ny film (heat-resistant gas barrier layer 21) via a two-component curing urethane adhesive (3 μm), as the sealant layer 13, and then dry-laminated by being sandwiched between a rubber nip roll and a laminating roll heated to 100°C and pressure-bonded to obtain a laminate that constitutes the exterior packaging material 1.

[0055] Next, this laminate was wound around a roll shaft and then aged at 40° C. for 10 days to obtain an exterior packaging material sample of Example 1.

[0056] 2. Measurement of breakdown voltage The dielectric breakdown voltage of the resin film constituting the heat-resistant gas barrier layer 21 in Example 1 was measured in accordance with JIS C2151 before the deposition film was formed. The results are also shown in Table 1.

[0057] 3. Measurement of hot water shrinkage A test piece measuring 10 cm × 10 cm was cut out from the resin film constituting the heat-resistant gas barrier layer 21 in Example 1, and the test piece was immersed in hot water at 95°C for 30 minutes. The dimensional change rate in the stretching direction of the test piece before and after immersion was calculated using the following formula.

[0058] Hot water shrinkage rate (%) = {(XY) / X} x 100 In this formula, "X" is the dimension in the stretching direction before the immersion treatment, and "Y" is the dimension in the stretching direction after the immersion treatment.

[0059] 4. Measuring seal strength

[0060] [Table 2]

[0061] The packaging material sample of Example 1 was cut into two pieces measuring 15 mm wide x 150 mm long, and then the pair of samples were overlapped so that their inner sealant layers were in contact with each other. Using a heat sealing device (TP-701-A) manufactured by Tester Sangyo Co., Ltd., heat sealing (thermal adhesion) was performed by heating on one side under the following conditions: heat sealing temperature: 200°C, sealing pressure: 0.2 MPa (gauge pressure), and sealing time: 2 seconds, thereby obtaining a sample for seal strength evaluation of Example 1.

[0062] The seal strength evaluation sample was subjected to T-peel testing at a tensile speed of 100 mm / min between the inner sealant layers of the sealed portion using a Shimadzu Access Strograph (AGS-5kNX) in accordance with JIS Z0238-1998, and the peel strength was measured. This was taken as the seal strength (N / 15 mm width). The results are shown in Table 2.

[0063] 5. Measurement of survival rate The packaging material sample of Example 1 was cut into two pieces measuring 15 mm wide x 150 mm long, and then the pair of samples were overlapped so that their inner sealant layers were in contact with each other. Using a heat sealing device (TP-701-A) manufactured by Tester Sangyo Co., Ltd., heat sealing (thermal bonding) was performed by heating on one side under the following conditions: heat sealing temperature: 200°C, sealing pressure: 0.2 MPa (gauge pressure), and sealing time: 2 seconds, thereby obtaining a sample for measuring the survival rate of Example 1.

[0064] In this sample for measuring the remaining rate, the sealed portion was hardened with resin, cut to expose the cross section, and the cross section was observed by SEM to determine the thickness of the heat-resistant gas barrier layer 21. The results are also shown in Table 2.

[0065] The layer thickness after heat sealing was defined as "da1" and the layer thickness before heat sealing was defined as "da1", and the residual ratio "da1 / da0" was measured. The results are also shown in Table 2.

[0066] 6. Measurement of insulation resistance (evaluation of insulation properties) As shown in FIGS. 3 and 4 , two pieces of packaging material sample 1 of Example 1 were cut out, each measuring 100 mm long and 50 mm wide. These paired packaging material samples 1, 1 were overlapped with their sealant layers 13 facing each other and in contact. Meanwhile, a 10 mm wide, 100 μm thick aluminum foil tab lead 3 was sandwiched between the pair of packaging material samples 1, 1, with 50 μm thick acid-modified polypropylene tab films 31 placed on both sides of the tab lead 3. The tab lead 3 was positioned so that a portion of the tab lead 3 was positioned between the pair of packaging material samples 1, 1, and the remaining portion was pulled outward from the edge of the pair of packaging material samples 1, 1. The sealant layers of these unbonded samples were heat-sealed from both the top and bottom surfaces of the packaging material samples 1, 1 using a double-sided heat sealer under conditions of a seal width of 5 mm, 200°C, and 0.2 MPa for 2 seconds, to obtain a sample for insulation evaluation.

[0067] In the plan view of the insulation evaluation sample in Fig. 3, the heat-bonded portion (heat-sealed portion) 131 is hatched with oblique lines to facilitate understanding of the invention. In the cross-sectional view of the insulation evaluation sample in Fig. 4, the heat-resistant gas barrier layer 13 is omitted to facilitate understanding of the structure.

[0068] Next, as shown in Figure 3, at the longitudinal end of the insulation evaluation sample, the resin serving as the base material layer 11 was partially peeled off to partially expose the aluminum foil serving as the metal foil layer 12, and electrical continuity with the aluminum foil (metal foil layer 12) from the outside was ensured at the exposed portion 121.

[0069] One terminal of an insulation resistance measuring device (manufactured by Hioki E.E. Corporation: product number "HIOKI3154") 6 was connected to the metal foil layer 12 in the exposed portion 121 of the insulation evaluation sample, and the other terminal was brought into contact with the tab lead 3 to form a circuit, and then a voltage of 25 V was applied between the metal foil layer 12 and the tab lead 3 in the circuit for 5 seconds, and the resistance was measured to obtain the insulation resistance value. The results are also shown in Table 2.

[0070] 7. Evaluation of formability A sample for formability evaluation was obtained by cutting the exterior packaging material sample of Example 1 into a size of 100 mm × 100 mm. A deep-draw forming test was performed on this sample for formability evaluation using a deep-draw forming die attached to a 25-ton press, with the forming height (drawing depth) being changed in 0.5 mm increments.

[0071] If the desired formability was obtained even when the formed height was 7 mm or more, it was evaluated as "◎", if the desired formability was not obtained at 7 mm or more but was obtained in the range of 5 mm to less than 7 mm, it was evaluated as "◯", and if the desired formability was not obtained at less than 5 mm, it was evaluated as "×". The results are also shown in Table 2.

[0072] 8. Evaluation of H2S gas permeation through O-Ny films with evaporated films The H2S gas permeability was measured according to JIS K7126 for the O-Ny film with a vapor-deposited film used in the packaging material sample of Example 1. The results are also shown in Table 2.

[0073] <Example 2> A sample of Example 2 was prepared in the same manner as in Example 1, except that a 3 μm-thick O-Ny film was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0074] Example 3 A sample of Example 3 was prepared in the same manner as in Example 1, except that a 15 μm thick O-Ny film was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0075] Example 4 A sample of Example 4 was prepared in the same manner as in Example 1, except that a 25 μm thick O-Ny film was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0076] <Example 5> A sample of Example 5 was prepared in the same manner as in Example 1, except that an O-Ny film with a thickness of 45 μm and a breakdown voltage of 20 kV / mm was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0077] Example 6 A sample of Example 6 was prepared in the same manner as in Example 1, except that an O-Ny film with a thickness of 12 μm, a breakdown voltage of 18 kV / mm, and a hot water shrinkage rate of 2% was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0078] Example 7 A sample of Example 7 was prepared in the same manner as in Example 1, except that an O-Ny film with a thickness of 15 μm and a hot water shrinkage rate of 8% was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0079] Example 8 A sample of Example 8 was prepared in the same manner as in Example 1, except that a PET film having a thickness of 5 μm, a melting point of 260° C., a breakdown voltage of 18 kV / mm, and a hot water shrinkage rate of 0.5% was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0080] Example 9 A sample of Example 9 was prepared in the same manner as in Example 1, except that an OPP film (biaxially oriented polypropylene film) with a thickness of 5 μm, a melting point of 165° C., a breakdown voltage of 22 kV / mm, and a hot water shrinkage rate of 0.1% was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0081] Example 10 A sample of Example 10 was prepared in the same manner as in Example 1, except that no vapor-deposited film was formed, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0082] Example 11 A sample of Example 10 was prepared in the same manner as in Example 1, except that the vapor-deposited film was made of alumina, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0083] Example 12 A sample of Example 10 was prepared in the same manner as in Example 1, except that a 900 nm thick alumina vapor deposition film was formed, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0084] Example 13 A sample of Example 10 was prepared in the same manner as in Example 1, except that a 1200 nm thick alumina vapor deposition film was formed, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0085] <Comparative Example 1> A sample of Comparative Example 1 was prepared in the same manner as in Example 1, except that an O-Ny film with a breakdown voltage of 15 kV / mm was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0086] <Comparative Example 2> A sample of Comparative Example 1 was prepared in the same manner as in Example 1, except that a 2 μm-thick O-Ny film was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0087] <Comparative Example 3> A sample of Comparative Example 1 was prepared in the same manner as in Example 1, except that a 55 μm-thick O-Ny film was used as the heat-resistant gas barrier layer 21, and the same measurements (evaluations) were carried out. The results are shown in Tables 1 and 2.

[0088] <Overall review> As is clear from Table 2, the packaging material samples of Examples 1 to 13 related to the present invention were able to obtain excellent results in all evaluations.

[0089] In contrast, the packaging material samples of Comparative Examples 1 to 3, which deviate from the gist of the present invention, failed to achieve good results in any of the evaluations. [Industrial Applicability]

[0090] The all-solid-state battery packaging material of the present invention can be suitably used as a material for a casing for housing a solid-state battery body. [Explanation of symbols]

[0091] 1: Exterior material 11: Base material layer 12: Metal foil layer 13: Sealant layer 21: Heat-resistant gas barrier layer 5: Solid-state battery body

Claims

1. An exterior material for an all-solid-state battery for encapsulating a solid-state battery body, the exterior material comprising: a base layer; a metal foil layer laminated on an inner surface side of the base layer; and a sealant layer laminated on the inner surface side of the metal foil layer, a heat-resistant gas barrier layer is provided between the metal foil layer and the sealant layer; the heat-resistant gas barrier layer is made of an insulating resin having a melting point 20°C or more higher than that of the sealant layer, the heat-resistant gas barrier layer has a breakdown voltage of 18 kV / mm or more and a thickness of 3 μm to 50 μm; The heat-resistant gas barrier layer is made of a resin having a hydrogen sulfide gas permeability of 30 {cc·mm / (m 2 ·D·MPa)} or less as measured in accordance with JIS K7126-1.

2. 2. The all-solid-state battery packaging material according to claim 1, wherein the resin constituting the heat-resistant gas barrier layer has a hot water shrinkage rate of 2% to 10%.

3. 3. The all-solid-state battery packaging material according to claim 1, wherein the resin constituting the heat-resistant gas barrier layer is polyamide.

4. a vapor deposition layer is formed between the heat-resistant gas barrier layer and the sealant layer, The all-solid-state battery exterior material according to any one of claims 1 to 3, wherein the vapor deposition layer is composed of at least one of a metal, a metal oxide, and a metal fluoride.

5. An all-solid-state battery, comprising a solid-state battery body encapsulated in the all-solid-state battery packaging material according to any one of claims 1 to 4.

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