JP7111264B2 - Exterior material for all-solid-state battery, manufacturing method thereof, and all-solid-state battery - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to an exterior material for an all-solid-state battery, a manufacturing method thereof, and an all-solid-state battery.

Conventionally, various types of power storage devices have been developed, and lithium ion batteries, for example, are used in a wide range of fields.

In all electricity storage devices, packaging materials (packaging materials) are essential members for sealing the electricity storage device elements such as electrodes and electrolytes. there is

A power storage device containing an electrolytic solution, such as a lithium ion battery, cannot be used in a temperature environment above the boiling point of the electrolytic solution. On the other hand, an all-solid battery in which the electrolyte is a solid electrolyte is known. An all-solid-state battery does not use an organic solvent in the battery, and thus has advantages such as high safety and a wide operating temperature range.

On the other hand, in all-solid-state batteries, due to expansion and contraction of the negative and positive electrodes during charging and discharging, separation between the solid electrolyte and the negative electrode active material layer or positive electrode active material layer is likely to occur, and the deterioration of the battery is likely to progress. Are known.

As a method for suppressing separation between a solid electrolyte and a negative electrode active material layer or a positive electrode active material layer, a technique of constraining an all-solid-state battery in a state of being pressed under high pressure is known. For example, in Patent Document 1, a stacking process for producing a laminate including a positive electrode current collector, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector in that order, and a laminate produced by the stacking process are disclosed. A battery comprising a pressurizing step of applying pressure in the stacking direction, and a restraining step of restraining the laminate while pressurizing it in the stacking direction for a predetermined time at a pressure of 0.1 MPa or more and 100 MPa or less after the pressurizing step. is disclosed.

JP 2012-142228 A Japanese Patent Application Laid-Open No. 2008-103288

In order to suppress separation between the solid electrolyte and the negative electrode active material layer or the positive electrode active material layer in the usage environment of the all-solid-state battery, the all-solid-state battery is pressed against the solid electrolyte by high pressure pressing from the outside of the exterior material. , the negative electrode active material layer and the positive electrode active material layer are desired to continue to be restrained.

On the other hand, in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., all-solid-state batteries are required to have various shapes, and are required to be thinner and lighter. However, conventional metal exterior materials, which are often used for batteries, have the disadvantage that it is difficult to follow the diversification of shapes and there is a limit to weight reduction. Therefore, as an exterior material that can be easily processed into various shapes and that can realize thinness and weight reduction, an exterior material made of a laminated film in which a base material, a metal foil layer, and a heat-fusible resin layer are sequentially laminated is proposed. Proposed.

In an exterior material made of such a laminated film, a space for housing a battery element is generally provided by molding into a bag or by molding using a mold, and electrodes, solid electrolytes, etc. are provided in the space. By disposing the battery elements and heat-sealing the heat-sealable resin layers, an all-solid-state battery in which the battery elements are housed inside the exterior material is obtained.

By applying the laminated film exterior material to the exterior material of all-solid-state batteries, it is expected to reduce the weight of electric vehicles and hybrid electric vehicles.

However, in a high-temperature environment, if the solid electrolyte, the negative electrode active material layer, and the positive electrode active material layer continue to be constrained from the outside of the exterior material of the all-solid-state battery in a high-pressure state, the heat-sealable resin layer of the exterior material will become the battery element. , the thickness of the heat-fusible resin layer (inner layer) of the exterior material may be reduced, and the barrier layer laminated on the exterior material may come into contact with the solid electrolyte.

Under such circumstances, the present disclosure provides an exterior material for an all-solid-state battery, which is composed of a laminate including, from the outside, at least, a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order. A main object of the present invention is to provide an exterior material for an all-solid-state battery that has excellent durability in a high-temperature, high-pressure environment.

The inventors of the present disclosure conducted extensive studies to solve the above problems. As a result, at least from the outside, the exterior material for an all-solid-state battery, which is composed of a laminate including a base material layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order, It was found that an all-solid-state battery exterior material having a residual rate of 80% or more of the total thickness of the adhesive layer and the heat-fusible resin layer, which is measured, has excellent durability in a high-temperature and high-pressure environment.

The present disclosure has been completed through further studies based on these findings. That is, the present disclosure provides inventions in the following aspects.
An exterior material for an all-solid-state battery, wherein the residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 80% or more.
<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraint jig, and in this state, it is placed in an oven at 120° C. and stored for 6 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples.

According to the present disclosure, an exterior material for an all-solid-state battery, which is composed of a laminate including at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside, It is possible to provide an exterior material for an all-solid-state battery that is excellent in environmental durability. Moreover, according to the present disclosure, it is also possible to provide a method for manufacturing an exterior material for an all-solid-state battery, and an all-solid-state battery.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of the cross-sectional structure of the all-solid-state battery to which the exterior material for all-solid-state batteries of this disclosure is applied. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of the cross-sectional structure of the all-solid-state battery to which the exterior material for all-solid-state batteries of this disclosure is applied. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view of an example of an all-solid-state battery to which the all-solid-state battery exterior material of the present disclosure is applied; 1 is a schematic cross-sectional view showing an example of a laminated structure of an exterior material for an all-solid-state battery of the present disclosure; FIG. 1 is a schematic cross-sectional view showing an example of a laminated structure of an exterior material for an all-solid-state battery of the present disclosure; FIG. 1 is a schematic cross-sectional view showing an example of a laminated structure of an exterior material for an all-solid-state battery of the present disclosure; FIG. It is a schematic diagram for demonstrating the insulation evaluation method in an Example.

The exterior material for an all-solid-state battery of the present disclosure is an exterior material for an all-solid-state battery, which is composed of a laminate including at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside. The residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 80% or more. The exterior material for an all-solid-state battery of the present disclosure has excellent durability in a high-temperature, high-pressure environment due to the configuration. In addition, the upper limit of the residual ratio of the total thickness is 100%.

<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraint jig, and in this state, it is placed in an oven at 120° C. and stored for 6 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples. The thickness is measured by cutting the measurement sample in the thickness direction using a microtome (for example, Yamato Koki Kogyo: REM-710 Ritratome), and observing the resulting cross section with a laser microscope (Keyence: VK-9700). and do.

The exterior material for an all-solid-state battery of the present disclosure will be described in detail below. In this specification, the numerical range indicated by "-" means "more than" and "less than". For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less.

1. Laminated structure and physical properties of all-solid battery exterior material 10 of the present disclosure (hereinafter sometimes referred to as "exterior material 10") is, for example, shown in FIGS. 4 to 6, at least , a substrate layer 1, a barrier layer 3, an adhesive layer 5, and a heat-fusible resin layer 4 in this order. In the exterior material 10, the base material layer 1 is on the outer layer side, and the heat-fusible resin layer 4 is on the inner layer side. When assembling an all-solid-state battery using the exterior material 10 and the battery element, the heat-sealable resin layers 4 of the exterior material 10 are opposed to each other, and the peripheral edge portions are heat-sealed to form a space. , in which the battery element is housed.

As shown in FIG. 5, the all-solid-state battery exterior material 10 has an adhesive layer between the base material layer 1 and the barrier layer 3 for the purpose of improving the adhesion between these layers, if necessary. 2. Further, as shown in FIG. 6, a surface coating layer 6 or the like may be provided on the outside of the base material layer 1 (the side opposite to the heat-fusible resin layer 4 side), if necessary.

The thickness of the laminate constituting the all-solid battery exterior material 10 is not particularly limited, but from the viewpoint of cost reduction, energy density improvement, etc., it is preferably about 10000 μm or less, about 8000 μm or less, and about 5000 μm or less. , From the viewpoint of maintaining the function of the all-solid battery exterior material 10 to protect the battery element, it is preferably about 100 μm or more, about 150 μm or more, about 200 μm or more. about 100 to 8000 μm, about 100 to 5000 μm, about 150 to 10000 μm, about 150 to 8000 μm, about 150 to 5000 μm, about 200 to 10000 μm, about 200 to 8000 μm, about 200 to 5000 μm, particularly about 100 to 500 μm. is preferred.

The details of each layer forming the all-solid-state battery exterior material 10 will be described in detail in the item "3. Each layer forming the all-solid-state battery exterior material".

In the all-solid-state battery exterior material 10 of the present disclosure, the residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the above measurement conditions is 80% or more, and the all-solid-state battery exterior From the viewpoint of further improving the durability of the material 10 in a high-temperature and high-pressure environment, it is preferably 90% or more, more preferably 95% or more, still more preferably 98% or more, still more preferably 99% or more, and still more preferably 100%. .

The all-solid battery exterior material 10 of the present disclosure is placed in an oven at 120 ° C. and stored for 24 hours. The residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer is preferably It is 40% or more, more preferably 45% or more, still more preferably 50% or more, still more preferably 60% or more, still more preferably 70% or more, and particularly preferably 75% or more. Note that the upper limit of the residual ratio of the total thickness is 100%.

Further, in the present disclosure, the all-solid-state battery exterior material 10 is placed in an oven at 120 ° C. and stored for 24 hours instead of "put in an oven at 120 ° C. and stored for 6 hours" under the above measurement conditions. ", the residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer, which is measured when % or more, more preferably 70% or more, particularly preferably 75% or more. Note that the upper limit of the residual ratio of the total thickness is 100%. In addition, the all-solid-state battery exterior material 10 of the present disclosure that satisfies the total thickness residual rate is 80 when "placed in an oven at 120 ° C. and stored for 6 hours" under the above measurement conditions. % or more, but it is preferable that the residual rate is 80% or more.

From the viewpoint of further improving the durability of the all-solid battery exterior material 10 in a high temperature and high pressure environment, the tensile elongation at break in a 120 ° C. environment of the laminate constituting the all-solid battery exterior material 10 is preferably about 300% or more. , more preferably about 350% or more, more preferably about 400% or more, and even more preferably about 545% or more. From the same point of view, the tensile elongation at break is preferably about 1000% or less, more preferably about 950% or less, even more preferably about 900% or less, still more preferably about 800% or less. The preferred range of the tensile elongation at break is about 300 to 1000%, about 300 to 950%, about 300 to 900%, about 300 to 800%, about 350 to 1000%, about 350 to 950%, 350 to 900 %, about 350-800%, about 400-1000%, about 400-950%, about 400-900%, about 400-800%, about 545-1000%, about 545-950%, about 545-900% , about 545 to 800%. In addition, the tensile elongation at break in a 23° C. environment of the laminate constituting the all-solid-state battery exterior material 10 is preferably about 350% or more, more preferably about 400% or more, and even more preferably about 450% or more. From the same point of view, the tensile elongation at break is preferably about 1000% or less, more preferably about 900% or less, and even more preferably about 800% or less. The preferred range of the tensile elongation at break is about 350 to 1000%, about 350 to 900%, about 350 to 800%, about 400 to 1000%, about 400 to 900%, about 400 to 800%, and 450 to 1000%. %, about 450 to 900%, and about 450 to 800%. The method for measuring the tensile strength at break is as follows.

[Measurement of tensile elongation at break of laminate]
The tensile elongation at break of the laminate constituting the exterior material is measured using a tensile tester (for example, AG-Xplus (trade name) manufactured by Shimadzu Corporation) in accordance with JIS K7127. The test sample width is JIS-K 6251-7 type dumbbell type, the distance between gauge lines is 15 mm, the tensile speed is 50 mm / min, the test environment is 23 ° C. or 120 ° C., respectively, 3 in the direction of MD and TD shall be the average value of times measured. That is, six test samples are prepared and measured, and an average value is obtained.

In addition, from the viewpoint of further improving the durability of the all-solid-state battery exterior material 10 in a high-temperature and high-pressure environment, the tensile breaking strength of the laminate constituting the all-solid-state battery exterior material 10 in a 120 ° C. environment is preferably about 5 MPa or more. , more preferably about 8 MPa or more, more preferably about 10 MPa or more, and even more preferably about 15 MPa or more. From the same point of view, the tensile strength at break is preferably about 50 MPa or less, more preferably about 40 MPa or less, even more preferably about 30 MPa or less, still more preferably about 25 MPa or less. The preferred range of the tensile breaking strength is about 5 to 50 MPa, about 5 to 40 MPa, about 5 to 30 MPa, about 5 to 25 MPa, about 8 to 50 MPa, about 8 to 40 MPa, about 8 to 30 MPa, about 8 to 25 MPa, About 10 to 50 MPa, about 10 to 40 MPa, about 10 to 30 MPa, about 10 to 25 MPa, about 15 to 50 MPa, about 15 to 40 MPa, about 15 to 30 MPa, and about 15 to 25 MPa. In addition, the tensile breaking strength of the laminate constituting the all-solid-state battery exterior material 10 in a 23° C. environment is preferably about 10 MPa or more, more preferably about 15 MPa or more, and even more preferably about 18 MPa or more. From the same point of view, the tensile strength at break is preferably about 60 MPa or less, more preferably about 50 MPa or less, even more preferably about 40 MPa or less, still more preferably about 35 MPa or less. The preferred range of the tensile breaking strength is about 10 to 60 MPa, about 10 to 50 MPa, about 10 to 40 MPa, about 10 to 35 MPa, about 15 to 60 MPa, about 15 to 50 MPa, about 15 to 40 MPa, about 15 to 35 MPa, 18 to 60 MPa, 18 to 50 MPa, 18 to 40 MPa, and 18 to 35 MPa. The method for measuring the tensile strength at break in each temperature environment is as follows.

[Measurement of tensile breaking strength of laminate]
The tensile breaking strength of the laminate constituting the exterior material is measured using a tensile tester (for example, AG-Xplus (trade name) manufactured by Shimadzu Corporation) in accordance with JIS K7127. The test sample width is JIS-K 6251-7 type dumbbell type, the distance between gauge lines is 15 mm, the tensile speed is 50 mm / min, the test environment is 23 ° C. or 120 ° C., respectively, 3 in the direction of MD and TD shall be the average value of times measured. That is, six test samples are prepared and measured, and an average value is obtained.

2. All-solid-state battery The all-solid-state battery to which the exterior material 10 for an all-solid-state battery of the present disclosure is applied is not particularly limited except that a specific exterior material 10 is used. That is, the configurations (electrodes, terminals, etc.) other than the solid electrolyte layer 40 and the exterior material 10 are not particularly limited as long as they are applied to all-solid-state batteries, and are used in known all-solid-state batteries. may be Hereinafter, the all-solid-state battery 70 of the present disclosure will be used as an example to specifically describe a mode in which the exterior material 10 for an all-solid-state battery of the present disclosure is applied to an all-solid-state battery.

As shown in the schematic diagrams of FIGS. 1 and 2, the all-solid-state battery 70 of the present disclosure includes a positive electrode active material layer 31, a negative electrode active material layer 21, and between the positive electrode active material layer 31 and the negative electrode active material layer 21 A battery element including at least a unit cell 50 including a solid electrolyte layer 40 laminated on a substrate is accommodated in a package formed by the all-solid-state battery outer packaging material 10 of the present disclosure. More specifically, the positive electrode active material layer 31 is laminated on the positive electrode collector 32 to form the positive electrode layer 30, and the negative electrode active material layer 21 is laminated on the negative electrode collector 22 to form the negative electrode. It constitutes layer 20 . The positive electrode current collector 32 and the negative electrode current collector 22 are each joined to a terminal 60 exposed to the outside and electrically connected to the external environment. A solid electrolyte layer 40 is laminated between the positive electrode layer 30 and the negative electrode layer 20 , and the positive electrode layer 30 , the negative electrode layer 20 , and the solid electrolyte layer 40 constitute the cell 50 . A battery element of the all-solid-state battery 70 may include only one unit cell 50 or may include a plurality of unit cells 50 . FIG. 1 shows an all-solid-state battery 70 including two cells 50 as battery elements, and FIG. 2 shows an all-solid-state battery 70 in which three cells 50 are stacked to form a battery element. showing.

In the all-solid-state battery 70, the terminal 60 connected to each of the positive electrode layer 30 and the negative electrode layer 20 is protruding outward, and the flange portion (the heat-sealable resin layers 4 are in contact with each other) is attached to the peripheral edge of the battery element. region) is formed, the battery element is covered, and the heat-sealing resin layers 4 of the flange portion are heat-sealed to form an all-solid-state battery using the exterior material for an all-solid-state battery. . When housing the battery element in the package formed by the all-solid-state battery exterior material 10 of the present disclosure, the heat-sealable resin portion of the all-solid-state battery exterior material 10 of the present disclosure is inside (with the battery element contact surface) to form a package.

As described above, the all-solid-state battery to which the exterior material 10 of the present disclosure is applied is not particularly limited as long as the solid electrolyte contains a sulfide solid electrolyte material and the specific exterior material 10 is used. , the same applies to the all-solid-state battery 70 of the present disclosure. Hereinafter, materials of members constituting a battery element of an all-solid-state battery to which the exterior material 10 of the present disclosure is applied are exemplified.

As described above, in the battery element of the all-solid-state battery 70 , at least the positive electrode layer 30 , the negative electrode layer 20 , and the solid electrolyte layer 40 constitute the cell 50 . The cathode layer 30 has a structure in which a cathode active material layer 31 is laminated on a cathode current collector 32 . The negative electrode layer 20 has a structure in which a negative electrode active material layer 21 is laminated on a negative electrode current collector 22 . The positive electrode current collector 32 and the negative electrode current collector 22 are respectively joined to terminals 60 exposed to the outside and electrically connected to the external environment.

[Positive electrode active material layer 31]
The positive electrode active material layer 31 is a layer containing at least a positive electrode active material. In addition to the positive electrode active material, the positive electrode active material layer 31 may further contain a solid electrolyte material, a conductive material, a binder, and the like, if necessary.

The positive electrode active material is not particularly limited, and examples thereof include an oxide active material and a sulfide active material. When the all-solid battery is an all-solid lithium battery, examples of oxide active materials used as positive electrode active materials include LiCoO ₂ , LiMnO ₂ , LiNiO ₂ , LiVO ₂ and LiNi _1/3 Co _1/3 Mn ₁ . rock salt layer type active materials such as _{/ 3O2} , _spinel type active materials such as _LiMn2O4 and Li _{( Ni0.5Mn1.5} ) _O4 , _olivine type active materials such as _LiFePO4 and _LiMnPO4 , _Li2FeSiO4 , Examples include Si-containing active materials such as Li ₂ MnSiO ₄ . Examples of sulfide active materials used as positive electrode active materials for all-solid-state lithium batteries include copper schuberls, iron sulfides, cobalt sulfides, and nickel sulfides.

Although the shape of the positive electrode active material is not particularly limited, for example, it may be in the form of particles. The average particle size (D ₅₀ ) of the positive electrode active material is preferably, for example, approximately 0.1 to 50 μm. Also, the content of the positive electrode active material in the positive electrode active material layer 31 is preferably about 10 to 99% by mass, more preferably about 20 to 90% by mass.

The positive electrode active material layer 31 preferably further contains a solid electrolyte material. Thereby, the ion conductivity in the positive electrode active material layer 31 can be improved. The solid electrolyte material contained in the positive electrode active material layer 31 is the same as the solid electrolyte material exemplified for the solid electrolyte layer 40 described later. The content of the solid electrolyte material in the positive electrode active material layer is preferably about 1 to 90% by mass, more preferably about 10 to 80% by mass.

The positive electrode active material layer 31 may further contain a conductive material. Addition of the conductive material can improve the electron conductivity of the positive electrode active material layer. Examples of conductive materials include acetylene black, ketjen black, and carbon fiber. Moreover, the positive electrode active material layer may further contain a binder. Examples of binders include fluorine-containing binders such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF).

The thickness of the positive electrode active material layer 31 is appropriately set according to the size of the all-solid-state battery and the like, and is preferably about 0.1 to 1000 μm.

[Positive electrode current collector 32]
Materials constituting the positive electrode current collector 32 include, for example, stainless steel (SUS), aluminum, nickel, iron, titanium, and carbon.

The thickness of the positive electrode current collector 32 is appropriately set according to the size of the all-solid-state battery and the like, and is preferably about 10 to 1000 μm.

[Negative electrode active material layer 21]
The negative electrode active material layer 21 is a layer containing at least a negative electrode active material. In addition to the negative electrode active material, the negative electrode active material layer 21 may contain a solid electrolyte material, a conductive material, a binder, and the like, if necessary.

The negative electrode active material is not particularly limited, and examples thereof include carbon active materials, metal active materials, oxide active materials, and the like. Carbon active materials include, for example, mesocarbon microbeads (MCMB), graphite such as highly oriented graphite (HOPG), amorphous carbon such as hard carbon and soft carbon, and the like. Examples of metal active materials include In, Al, Si and Sn. Examples of oxide active materials include Nb ₂ O ₅ , Li ₄ Ti ₅ O ₁₂ and SiO.

The shape of the negative electrode active material is not particularly limited, and examples thereof include a particle shape and a film shape. The average particle size (D ₅₀ ) of the negative electrode active material is preferably about 0.1 to 50 μm. Further, the content of the negative electrode active material in the negative electrode active material layer 21 is, for example, approximately 10 to 99% by mass, more preferably approximately 20 to 90% by mass.

The negative electrode active material layer 21 preferably further contains a solid electrolyte material. Thereby, the ion conductivity in the negative electrode active material layer 21 can be improved. The solid electrolyte material contained in the negative electrode active material layer 21 is the same as the solid electrolyte material exemplified for the solid electrolyte layer 40 described later. The content of the solid electrolyte material in the negative electrode active material layer 21 is preferably about 1 to 90% by mass, more preferably about 10 to 80% by mass.

The negative electrode active material layer 21 may further contain a conductive material. Moreover, the negative electrode active material layer 21 may further contain a binder. The conductive material and the binder are the same as those exemplified for the positive electrode active material layer 31 described above.

The thickness of the negative electrode active material layer 21 is appropriately set according to the size of the all-solid-state battery and the like, and is preferably about 0.1 to 1000 μm.

[Negative electrode current collector 22]
Examples of materials that constitute the negative electrode current collector 22 include stainless steel (SUS), copper, nickel, and carbon.

The thickness of the negative electrode current collector 22 is appropriately set according to the size of the all-solid-state battery and the like, and is preferably about 10 to 1000 μm.

[Solid electrolyte layer 40]
Solid electrolyte layer 40 is a layer containing a solid electrolyte material. Solid electrolyte materials include, for example, sulfide solid electrolyte materials and oxide solid electrolyte materials.

Sulfide solid electrolyte materials are preferable in that many of them have higher ionic conductivity than oxide solid electrolyte materials, and oxide solid electrolyte materials have higher chemical stability than sulfide solid electrolyte materials. point is preferable.

Specific examples of oxide solid electrolyte materials include, for example, compounds having a NASICON structure. An example of a compound having a NASICON structure is a compound represented by the general formula Li1 ₊ xAlxGe2 _{-x (} PO4) ₃ ( _0≤x≤2 ). Among them, the compound is _{preferably Li1.5Al0.5Ge1.5 ( PO4} ) ₃ . Another example of a compound having a NASICON structure is a compound represented by the general formula Li1 ₊ xAlxTi2 _-x (PO4) ₃ ( _0≤x≤2 ). Among them, the compound is _{preferably Li1.5Al0.5Ti1.5 ( PO4} ) ₃ . Other examples of oxide solid electrolyte materials used in all-solid lithium secondary batteries include _LiLaTiO (e.g., _{Li0.34La0.51TiO3} ), _LiPON (e.g. _{, Li2.9PO3.3N0.46} ), _LiLaZrO (e.g., , Li ₇ La ₃ Zr ₂ O ₁₂ ) and the like.

Specific examples of sulfide solid electrolyte materials include Li ₂ SP ₂ S ₅ , Li ₂ SP _{2 S 5 -LiI, Li 2 SP 2 S 5 -Li 2 O ,} Li ₂ S- P ₂ S ₅ —Li ₂ O—LiI, Li ₂ S—SiS ₂ , Li ₂ S—SiS ₂ —LiI, Li ₂ 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 -ZmSn (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, y is a positive number, and M is any one of P, Si, Ge, B, Al, Ga, and In.). The above description of "Li ₂ SP _{2 S 5 " means a sulfide solid electrolyte material using a raw material composition containing Li 2 S and P 2 S 5 , and} the same applies to other descriptions. be. Also, the sulfide solid electrolyte material may be sulfide glass or crystallized sulfide glass.

The content of the solid electrolyte material in the solid electrolyte layer 40 is not particularly limited, but is preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more. The solid electrolyte layer may contain a binder, or may be composed only of a solid electrolyte material.

The thickness of the solid electrolyte layer 40 is appropriately set according to the size of the all-solid-state battery and the like, preferably about 0.1 to 1000 μm, more preferably about 0.1 to 300 μm.

The all-solid-state battery 70 of the present disclosure can be used in an environment where it is constrained from the outside under high pressure. In this case, the pressure that constrains the all-solid-state battery 70 from the outside is, from the viewpoint of suitably suppressing separation between the solid electrolyte and the negative electrode active material layer (further between the solid electrolyte and the positive electrode active material layer), Preferably about 0.1 MPa or more, more preferably about 5 MPa or more, still more preferably about 10 MPa or more, preferably about 100 MPa or less, more preferably about 30 MPa or less, with a preferred range of 0.1 about 100 MPa, about 0.1 to 70 MPa, about 5 to 100 MPa, about 5 to 70 MPa, about 10 to 100 MPa, and about 1 to 30 MPa.

As a method of constraining the all-solid-state battery 70 from the outside under high pressure, the all-solid-state battery is sandwiched between metal plates or the like and fixed in a state of being pressed under high pressure (for example, tightened with a vise), or a method such as gas pressurization. is mentioned.

From the same viewpoint, the temperature at which the all-solid-state battery 70 is restrained from the outside is preferably 20° C. or higher, more preferably 40° C. or higher, and preferably 200° C. or lower, more preferably 150° C. or lower. A preferred range is about 20 to 150°C.

Although the shape of the all-solid-state battery 70 of the present disclosure is not particularly limited, it is preferably rectangular in plan view, as shown in the schematic diagram of FIG. 3, for example. Furthermore, the ratio of the length of the first side of the all-solid-state battery 70 rectangular in plan view to the length of the second side perpendicular to the first side (length of the first side: length of the second side) is preferably about 1:1 to 1:5, more preferably about 1:1 to 1:3. If the length of the second side is too long relative to the first side, it becomes difficult to fix the second side to the mold when molding the exterior material 10 to form a molded portion M, which will be described later. The R value (curvature radius) of the ridge (first curved portion described later) along the second side of M tends to be too large.

As shown in the schematic diagrams of FIGS. 1 to 3, in the all-solid-state battery 70 of the present disclosure, the battery element is formed so that the exterior material 10 protrudes from the heat-fusible resin layer 4 side to the barrier layer 3 side. It is preferably housed in the molded portion M which is rectangular in plan view. FIG. 1 shows a diagram in which a molding portion M is formed on one side of an all-solid-state battery 70 . Further, FIG. 2 shows a diagram in which the molding portions M are formed on both sides of the all-solid-state battery 70 .

In the present disclosure, when the all-solid-state battery 70 is viewed from the outer surface side of the exterior material 10, two sides parallel to each other of the rectangular molded portion M (two sides parallel to the y direction in FIGS. 1 to 3, Or, a straight line parallel to the two sides parallel to the z direction) and passing through the middle of the two parallel sides (see the broken line Y in the y direction and the broken line Z in the z direction in FIG. 3) , a first curved portion R1 (see R1z in FIG. 2) and a second curved portion R2 (see R2z in FIG. 2) in this order from the center to the end of the exterior material 10 in the cross section in the thickness direction of the exterior material 10. and the R value (radius of curvature) of the first curved portion R1 is preferably 1 mm or more. When the R value (curvature radius) is 1 mm or more, the force with which the exterior material 10 is stretched at the corners (corners) of the rectangular molding portion M does not become too large, and the molding depth reaches the predetermined molding depth. In addition, the occurrence of pinholes or the like in the barrier layer 3 is suppressed. When the exterior material 10 is molded using a mold, the exterior material 10 protrudes from the heat-fusible resin layer 4 side toward the barrier layer 3 side, forming the first curved portion R1 and the second curved portion R1. A molded portion M is formed comprising a portion R2. In the molded portion M, the first curved portion R1 is located at a position protruding to the outside of the all-solid-state battery.

In the schematic diagram of FIG. 3, the cross-sectional view on the dashed line Z corresponds to the schematic diagram of FIG. , and a second curved portion R2z. In the schematic diagram of FIG. 3, in the cross section along the dashed line Y, the molded portion M includes a first curved portion R1y and a second curved portion R2y in order from the center to the end of the exterior material 10. . Note that the notation “first curved portion R1z” means the first curved portion in the z direction. Similarly, the notation “second curved portion R2z” means the second curved portion in the z direction, and the notation “first curved portion R1y” means the first curved portion in the y direction. , the second curved portion R2y means the second curved portion in the y-direction. Similarly to the R value of the first curved portion R1, if the R value (curvature radius) of the first curved portion R1y is 1 mm or more, the outer material The R value (radius of curvature) is 1 mm or more because the force for stretching 10 does not become too large and the occurrence of pinholes or the like in the barrier layer 3 before reaching a predetermined molding depth is suppressed. is preferred.

In the present disclosure, the R values (curvature radii) of the first curved portion R1 and the second curved portion R2 are respectively on the barrier layer 3 side of the exterior material 10 (that is, on the outer surface side of the exterior material 10). is the R value (curvature radius) on the surface of ).

In the all-solid-state battery of the present disclosure, for the purpose of minimizing the dead space inside the battery and increasing the volumetric energy density, if explained in FIG. The first side is a short side, the second side parallel to the z direction is a long side, and the first side along the short side parallel to the y direction in which the terminal of the all-solid-state battery having a rectangular shape in plan view is installed The R value (curvature radius) at the curved portion R1z is preferably larger than the R value (curvature radius) at the first curved portion R1y along the long side parallel to the z direction.

3. Each layer forming the exterior material for an all-solid-state battery The exterior material 10 of the present disclosure includes at least a laminate comprising a base material layer 1, a barrier layer 3, an adhesive layer 5, and a heat-fusible resin layer 4 in this order from the outside. It is configured. Hereinafter, each layer constituting the exterior material 10 of the present disclosure will be described in detail.

[Base material layer 1]
In the present disclosure, the base material layer 1 is provided outside the barrier layer 3 (in the case of having a barrier layer protective film 3b described later, the barrier layer protects It is a layer provided outside the membrane 3b). The base material layer 1 is positioned on the outer layer side of the exterior material 10 .

The material forming the base material layer 1 is not particularly limited as long as it functions as a base material, that is, at least has insulating properties. The base material layer 1 can be formed using, for example, a resin, and the resin may contain additives described later.

For example, a resin film made of resin may be used to form the base material layer 1, or a resin film may be formed by applying a resin when forming the base material layer 1. FIG. The resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, with biaxially stretched films being preferred. Examples of stretching methods for forming a biaxially stretched film include successive biaxial stretching, inflation, and simultaneous biaxial stretching. Methods for applying the resin include a roll coating method, a gravure coating method, an extrusion coating method, and the like.

Examples of the resin forming the base material layer 1 include resins such as polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenolic resin, and modified products of these resins. Further, the resin forming the base material layer 1 may be a copolymer of these resins or a modified product of the copolymer. Furthermore, it may be a mixture of these resins.

As resin which forms the base material layer 1, polyester and polyamide are preferably mentioned among these.

Specific examples of polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester. Among these, polyethylene terephthalate is preferred. Examples of copolyester include copolyester having ethylene terephthalate as a main repeating unit. Specifically, copolymer polyester polymerized with ethylene isophthalate with ethylene terephthalate as the main repeating unit (hereinafter abbreviated after polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/phenyl-dicarboxylate), polyethylene (terephthalate/decanedicarboxylate), and the like. These polyesters may be used singly or in combination of two or more.

Further, as the polyamide, specifically, aliphatic polyamide such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, copolymer of nylon 6 and nylon 66; terephthalic acid and / or isophthalic acid Hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamide such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) containing structural units derived from, polyamide MXD6 (polymetallic Polyamides containing aromatics such as silylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); Copolymerized polyamides, polyesteramide copolymers and polyetheresteramide copolymers which are copolymers of copolymerized polyamides with polyesters or polyalkylene ether glycols; and polyamides such as these copolymers. These polyamides may be used singly or in combination of two or more.

The substrate layer 1 preferably includes at least one of a polyester film, a polyamide film, and a polyolefin film, preferably includes at least one of an oriented polyester film, an oriented polyamide film, and an oriented polyolefin film, More preferably, at least one of oriented polyethylene terephthalate film, oriented polybutylene terephthalate film, oriented nylon film and oriented polypropylene film is included, biaxially oriented polyethylene terephthalate film, biaxially oriented polybutylene terephthalate film and biaxially oriented nylon film. , biaxially oriented polypropylene film.

The base material layer 1 may be a single layer, or may be composed of two or more layers. When the substrate layer 1 is composed of two or more layers, the substrate layer 1 may be a laminate obtained by laminating resin films with an adhesive or the like, or may be formed by co-extrusion of resin to form two or more layers. It may also be a laminate of resin films. A laminate of two or more resin films formed by coextrusion of resin may be used as the base material layer 1 without being stretched, or may be used as the base material layer 1 by being uniaxially or biaxially stretched. When the substrate layer 1 is a single layer, the substrate layer 1 is preferably composed of a single layer of polyester (especially polyethylene terephthalate).

Specific examples of the laminate of two or more resin films in the substrate layer 1 include a laminate of a polyester film and a nylon film, a laminate of nylon films of two or more layers, and a laminate of polyester films of two or more layers. etc., preferably a laminate of a stretched nylon film and a stretched polyester film, a laminate of two or more layers of stretched nylon films, and a laminate of two or more layers of stretched polyester films. For example, when the substrate layer 1 is a laminate of two layers of resin films, a laminate of polyester films and polyester films, a laminate of polyamide resin films and polyamide resin films, or a laminate of polyester films and polyamide resin films. A laminate of polyethylene terephthalate film and polyethylene terephthalate film, a laminate of nylon film and nylon film, or a laminate of polyethylene terephthalate film and nylon film is more preferred.

When the substrate layer 1 is a laminate of two or more layers of resin films, the two or more layers of resin films may be laminated via an adhesive. Preferred adhesives are the same as those exemplified for the adhesive layer 2 described later. The method for laminating two or more layers of resin films is not particularly limited, and known methods can be employed. Examples thereof include dry lamination, sandwich lamination, extrusion lamination, thermal lamination, and the like. A lamination method is mentioned. When laminating by dry lamination, it is preferable to use a polyurethane adhesive as the adhesive. At this time, the thickness of the adhesive is, for example, about 2 to 5 μm. Alternatively, an anchor coat layer may be formed on the resin film and laminated. As the anchor coat layer, the same adhesives as those exemplified in the adhesive layer 2 described later can be used. At this time, the thickness of the anchor coat layer is, for example, about 0.01 to 1.0 μm.

At least one of the surface and the inside of the substrate layer 1 may contain additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents. good. Only one type of additive may be used, or two or more types may be mixed and used.

In the present disclosure, from the viewpoint of improving the moldability of the exterior material 10, it is preferable that a lubricant exists on the surface of the base material layer 1. The lubricant is not particularly limited, but preferably includes an amide-based lubricant. Specific examples of amide lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide and the like. Further, specific examples of methylolamide include methylol stearamide. Specific examples of saturated fatty acid bisamides include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, and hexamethylenebisstearin. acid amide, hexamethylenebisbehenamide, hexamethylenehydroxystearic acid amide, N,N'-distearyladipic acid amide, N,N'-distearylsebacic acid amide and the like. Specific examples of unsaturated fatty acid bisamides include ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N'-dioleyladipic acid amide, and N,N'-dioleylsebacic acid amide. etc. Specific examples of fatty acid ester amides include stearamide ethyl stearate. Further, specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N,N'-distearyl isophthalic acid amide and the like. Lubricants may be used singly or in combination of two or more.

When a lubricant exists on the surface of the base material layer 1, its amount is not particularly limited, but is preferably about 3 mg/m ² or more, more preferably about 4 to 15 mg/m ² , and still more preferably 5 to 14 mg. / m ² degree.

The lubricant present on the surface of the substrate layer 1 may be obtained by exuding the lubricant contained in the resin constituting the substrate layer 1, or by coating the surface of the substrate layer 1 with the lubricant. may

The thickness of the base material layer 1 is not particularly limited as long as it functions as a base material. When the substrate layer 1 is a laminate of two or more resin films, the thickness of each resin film constituting each layer is preferably about 2 to 25 μm.

[Adhesive layer 2]
In the exterior material 10, the adhesive layer 2 is the adhesiveness between the base material layer 1 and the barrier layer 3 (the adhesiveness between the base material layer 1 and the barrier layer protective film 3b when the barrier layer protective film 3b is provided). It is a layer provided between them, if necessary, for the purpose of increasing the

The adhesive layer 2 is formed of an adhesive capable of bonding the base material layer 1 and the barrier layer 3 (or barrier layer protective film 3b). The adhesive used to form the adhesive layer 2 is not limited, but may be any of a chemical reaction type, a solvent volatilization type, a hot melt type, a hot pressure type, and the like. Further, it may be a two-liquid curing adhesive (two-liquid adhesive), a one-liquid curing adhesive (one-liquid adhesive), or a resin that does not involve a curing reaction. Further, the adhesive layer 2 may be a single layer or multiple layers.

Specific examples of the adhesive component contained in the adhesive include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester; polyether; polyurethane; epoxy resin; Phenolic resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefin resins such as polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins; polyvinyl acetate; cellulose; (meth)acrylic resins; polyimide; polycarbonate; amino resin such as urea resin and melamine resin; rubber such as chloroprene rubber, nitrile rubber and styrene-butadiene rubber; These adhesive components may be used singly or in combination of two or more. Among these adhesive components, polyurethane adhesives are preferred. In addition, an appropriate curing agent can be used in combination with these adhesive component resins to increase the adhesive strength. The curing agent is selected from among polyisocyanates, polyfunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, etc., depending on the functional groups of the adhesive component.

Examples of polyurethane adhesives include polyurethane adhesives containing a first agent containing a polyol compound and a second agent containing an isocyanate compound. Preferred examples include a two-component curing type polyurethane adhesive comprising a polyol such as polyester polyol, polyether polyol, and acrylic polyol as the first agent and an aromatic or aliphatic polyisocyanate as the second agent. Moreover, as the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group in a side chain in addition to the terminal hydroxyl group of the repeating unit.

Further, the adhesive layer 2 may contain other components as long as they do not impede adhesion, and may contain colorants, thermoplastic elastomers, tackifiers, fillers, and the like. Since the adhesive layer 2 contains a coloring agent, the exterior material 10 can be colored. Known substances such as pigments and dyes can be used as the colorant. In addition, only one type of colorant may be used, or two or more types may be mixed and used.

The type of pigment is not particularly limited as long as it does not impair the adhesiveness of the adhesive layer 2 . Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments. Examples of pigments include carbon black, titanium oxide, cadmium, lead, chromium oxide, and iron pigments, as well as fine powder of mica and fish scale foil.

Among the coloring agents, carbon black is preferable, for example, in order to make the external appearance of the exterior material 10 black.

The average particle size of the pigment is not particularly limited, and is, for example, approximately 0.05 to 5 μm, preferably approximately 0.08 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction/scattering particle size distribution analyzer.

The content of the pigment in the adhesive layer 2 is not particularly limited as long as the exterior material 10 is colored.

The thickness of the adhesive layer 2 is not particularly limited as long as the substrate layer 1 and the barrier layer 3 can be adhered. Preferred ranges include about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, and about 2 to 5 μm.

[Colored layer]
The colored layer is a layer provided between the substrate layer 1 and the barrier layer 3 (or the barrier layer protective film 3b) as necessary (not shown). When the adhesive layer 2 is provided, a colored layer may be provided between the base material layer 1 and the adhesive layer 2 and between the adhesive layer 2 and the barrier layer 3 (or the barrier layer protective film 3b). . Further, a colored layer may be provided outside the base material layer 1 . By providing the colored layer, the exterior material 10 can be colored.

The colored layer is formed, for example, by applying an ink containing a coloring agent to the surface of the substrate layer 1 or the surface of the barrier layer 3 (the surface of the barrier layer protective film 3b when the barrier layer protective film 3b is provided). can be formed. Known substances such as pigments and dyes can be used as the colorant. In addition, only one type of colorant may be used, or two or more types may be mixed and used.

Specific examples of the colorant contained in the colored layer are the same as those exemplified in the section [Adhesive layer 2].

[Barrier layer protective films 3a and 3b]
In the exterior material 10, a barrier layer protective film 3a is provided on the surface of the barrier layer 3 on the heat-fusible resin layer 4 side, if necessary. In the exterior material 10, only the surface of the barrier layer 3 on the heat-fusible resin layer 4 side may be provided with the barrier layer protective film 3a, or both surfaces of the barrier layer 3 may be provided with the barrier layer protective film 3a, respectively. , 3b. In the all-solid-state battery 70 of the present disclosure, it is preferable to include a barrier layer protective film 3a on the surface on the heat-fusible resin layer side. Moreover, from the viewpoint of improving the adhesion of the barrier layer 3, it is preferable to provide barrier layer protective films 3a and 3b on both sides of the barrier layer.

In the all-solid-state battery 70 of the present disclosure, when the barrier layer protective film 3a of the exterior material 10 is analyzed using time-of-flight secondary ion mass spectrometry, the peak intensity P _CrPO4 derived from _CrPO4 ⁻ The ratio P _{PO3 /CrPO4} of peak intensities P _PO3 derived from ₃ ⁻ is preferably in the range of 6-120.

In an all-solid-state battery, the all-solid-state battery may be restrained by high-pressure pressing from the outside of the exterior material in order to suppress separation between the solid electrolyte and the negative electrode active material layer or the positive electrode active material layer. However, when the solid electrolyte, the negative electrode active material layer, and the positive electrode active material layer are restrained in a high pressure state from the outside of the exterior material of the all-solid-state battery, the heat-fusible resin layer of the exterior material is strongly pressed against the battery element, and the exterior material The thickness of the heat-fusible resin layer (inner layer) of the material becomes thin, and there is a risk that the barrier layer laminated on the exterior material may come into contact with the solid electrolyte. In particular, when the barrier layer of the exterior material and the solid electrolyte are in contact with each other and an electric current is passed between them, an alloy is formed on the surface of the barrier layer, resulting in deterioration of the barrier layer. On the other hand, in the all-solid-state battery 70 of the present disclosure, the barrier layer protective film 3a is provided on the surface of the barrier layer 3 of the exterior material 10, so that the all-solid-state battery 70 is restrained in a high pressure state. As a result, even when electricity is passed between the barrier layer 3 and the solid electrolyte layer 40 in a state in which the solid electrolyte penetrates the heat-fusible resin layer 4 and the adhesive layer 5, the alloy is formed on the surface of the barrier layer 3. is difficult to generate, and deterioration of the barrier layer 3 is effectively suppressed. In particular, since the peak intensity ratio _PPO3/CrPO4 of the barrier layer protective film 3a is within the range of 6 to 120, the formation of an alloy on the surface of the barrier layer 3 is more effectively suppressed. Deterioration is suppressed more effectively.

In the present disclosure, the ratio P _PO3/CrPO4 of the peak intensity P _PO3 derived from PO ₃ ⁻ to the peak intensity P _CrPO4 derived from CrPO ₄ ⁻ has a lower limit of preferably about 10 or more, and an upper limit of is about 115 or less, more preferably about 110 or less, and even more preferably about 50 or less. The preferred range of the ratio _PPO3/CrPO4 is about 6 to 120, about 6 to 115, about 6 to 110, about 6 to 50, about 10 to 120, about 10 to 115, about 10 to 110, 10 to about 50, with about 10 to 50 being more preferred, and about 25 to 32 being particularly preferred.

Further, in the present disclosure, when the barrier layer protective film is analyzed using time-of-flight secondary ion mass spectrometry, the peak intensity P derived from CrPO ₄ ⁻ derived from CrPO 4 − derived from PO ₂ ⁻ derived from _CrPO4 The _PO2 ratio _PPO2/CrPO4 is preferably in the range of 7-70.

The ratio P _{PO2 /CrPO4} of the peak intensity P _PO2 derived from PO ₂ ⁻ to the peak intensity P _CrPO4 derived from CrPO ₄ ⁻ is preferably in the range of 7 to 70, effectively suppressing deterioration of the barrier layer 3. From the viewpoint of the ratio P _{PO2 /CrPO4} , the lower limit is preferably about 10 or more, and the upper limit is preferably about 65 or less, more preferably about 50 or less. Preferable ranges of the ratio _PPO2/CrPO4 include about 7 to 70, about 7 to 65, about 7 to 50, about 10 to 70, about 10 to 65, and about 10 to 50. About 50 is more preferable, and about 15 to 37 is particularly preferable.

In the present disclosure, when the barrier layer protective films 3a and 3b are provided on both sides of the barrier layer 3, the peak intensity ratio _PPO3/CrPO4 is within the above range for both the barrier layer protective films 3a and 3b. _PPO2/CrPO4 is also preferably within the above range.

Specifically, the method of analyzing the barrier layer protective films 3a and 3b using time-of-flight secondary ion mass spectrometry is performed under the following measurement conditions using a time-of-flight secondary ion mass spectrometer. be able to.

(Measurement condition)
Primary ions: Double charged ions of bismuth clusters (Bi ₃ ⁺⁺ )
Primary ion acceleration voltage: 30 kV
Mass range (m/z): 0-1500
Measurement range: 100 μm×100 μm
Number of scans: 16 scans/cycle
Number of pixels (one side): 256 pixels
Etching ion: Ar gas cluster ion beam (Ar-GCIB)
Etching ion acceleration voltage: 5.0 kV

Moreover, it can be confirmed by using X-ray photoelectron spectroscopy that the barrier layer protective film contains chromium. Specifically, first, in the exterior material, layers laminated on the barrier layer (adhesive layer, heat-fusible resin layer, adhesive layer, etc.) are physically peeled off. Next, the barrier layer is placed in an electric furnace, and organic components present on the surface of the barrier layer are removed at about 300° C. for about 30 minutes. The inclusion of chromium is then confirmed using X-ray photoelectron spectroscopy of the surface of the barrier layer.

The barrier layer protective films 3a and 3b can be formed by chemically treating the surface of the barrier layer 3 with a treatment liquid containing a chromium compound such as chromium oxide.

As a chemical conversion treatment using a treatment liquid containing a chromium compound, for example, a solution in which a chromium compound such as chromium oxide is dispersed in phosphoric acid and/or a salt thereof is applied to the surface of the barrier layer 3 and baked. a method of forming a barrier layer protective film on the surface of the barrier layer 3 by carrying out.

The peak intensity ratio P _PO3/CrPO4 of the barrier layer protective films 3a and 3b and the peak intensity ratio P _PO2/CrPO4 are respectively determined by, for example, the composition of the treatment solution for forming the barrier layer protective films 3a and 3b, the post-treatment It can be adjusted by manufacturing conditions such as the temperature and time of baking treatment.

The ratio of the chromium compound and phosphoric acid and/or its salt in the treatment liquid containing the chromium compound is not particularly limited, but the peak intensity ratio P _PO3/CrPO4 and the peak intensity ratio P _PO2/CrPO4 are From the viewpoint of setting within the above range, the ratio of phosphoric acid and/or its salt to 100 parts by mass of the chromium compound is preferably about 30 to 120 parts by mass, more preferably about 40 to 110 parts by mass. . As phosphoric acid and its salt, for example, condensed phosphoric acid and its salt can also be used.

Moreover, the treatment liquid containing the chromium compound may further contain an anionic polymer and a cross-linking agent for cross-linking the anionic polymer. Examples of anionic polymers include poly(meth)acrylic acid or its salts, copolymers containing (meth)acrylic acid or its salts as main components, and the like. Examples of cross-linking agents include compounds having functional groups such as isocyanate groups, glycidyl groups, carboxyl groups, and oxazoline groups, and silane coupling agents. Each of the anionic polymer and the cross-linking agent may be of one kind, or two or more kinds thereof.

Moreover, from the viewpoint of effectively suppressing deterioration of the barrier layer 3, the treatment liquid containing the chromium compound preferably contains an aminated phenolic polymer or an acrylic resin. When the treatment liquid containing a chromium compound contains an aminated phenol polymer, the content of the aminated phenol polymer is preferably about 100 to 400 parts by mass, more preferably about 100 parts by mass, based on 100 parts by mass of the chromium compound. About 200 to 300 parts by mass can be mentioned. Moreover, the weight average molecular weight of the aminated phenol polymer is preferably about 5,000 to 20,000. The weight average molecular weight of the aminated phenol polymer is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard sample.

The acrylic resin is polyacrylic acid, acrylic acid methacrylic acid ester copolymer, acrylic acid maleic acid copolymer, acrylic acid styrene copolymer, or derivatives thereof such as sodium salts, ammonium salts, and amine salts. Preferably. In particular, derivatives of polyacrylic acid such as ammonium salt, sodium salt or amine salt of polyacrylic acid are preferred. In the present disclosure, polyacrylic acid means a polymer of acrylic acid. Further, the acrylic resin is preferably a copolymer of acrylic acid and dicarboxylic acid or dicarboxylic anhydride, and the ammonium salt, sodium salt, Alternatively, it is also preferably an amine salt. Only one type of acrylic resin may be used, or two or more types may be mixed and used.

The weight average molecular weight of the acrylic resin is preferably about 1,000 to 1,000,000, more preferably about 3,000 to 800,000, and still more preferably about 10,000 to 800,000. The higher the molecular weight, the higher the durability, but the water-solubility of the acrylic resin decreases, the coating liquid becomes unstable, and the manufacturing stability is lacking. Conversely, the smaller the molecular weight, the lower the durability. In the present disclosure, when the weight average molecular weight of the acrylic resin is 1,000 or more, the durability is high, and when it is 1,000,000 or less, the production stability is good. In the present disclosure, the weight average molecular weight of the acrylic resin is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard sample.

In addition, as for the acid value of the acrylic resin, it is considered that the more the COOH group is, the more effective it is to contribute to the adhesiveness, so the higher the value, the better. Since the amount of OC=O bonds may not be reflected in some cases, it is considered that analyzing OC=O bonds from the XPS spectrum as in the present disclosure can reflect adhesiveness.

In the treatment liquid containing a chromium compound, when an acrylic resin is contained, the content of the acrylic resin is preferably about 50 to 400 parts by mass, more preferably 80 to 200 parts by mass, with respect to 100 parts by mass of the chromium compound. part degree.

From the same point of view, the chromium compound is preferably at least one of chromium (III) fluoride and chromium (III) nitrate. It is thought that a coordinated crosslinked structure centered on Cr atoms and a highly durable film structure of aluminum fluoride are formed.

The solvent for the treatment liquid containing the chromium compound is not particularly limited as long as it disperses the components contained in the treatment liquid and is subsequently evaporated by heating, but water is preferred.

The solid content concentration of the chromium compound contained in the treatment liquid for forming the barrier layer protective films 3a and 3b is not particularly limited, but the peak intensity ratio P _PO3/CrPO4 and the peak intensity ratio P _PO2/CrPO4 From the viewpoint of effectively suppressing the deterioration of the barrier layer 3 by setting each of them to the predetermined range, for example, about 1 to 15% by mass, preferably about 7.0 to 12.0% by mass, more preferably 8% 0 to 11.0% by mass, more preferably 9.0 to 10.0% by mass.

The thickness of each of the barrier layer protective films 3a and 3b is not particularly limited, but from the viewpoint of effectively suppressing deterioration of the barrier layer 3, it is preferably about 1 nm to 10 μm, more preferably about 1 to 100 nm, and more preferably about 1 nm to 100 nm. Preferably, it is about 1 to 50 nm. The thickness of the barrier layer protective film can be measured by observation with a transmission electron microscope, or by a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy.

From the same point of view, the amount of the barrier layer protective films 3a and 3b per 1 m ² of the surface of the barrier layer 3 is preferably about 1 to 500 mg, more preferably about 1 to 100 mg, still more preferably about 1 to 50 mg. is mentioned.

Examples of methods for applying the treatment liquid containing the chromium compound to the surface of the barrier layer include bar coating, roll coating, gravure coating, and dipping.

The peak intensity ratio P _PO3/CrPO4 and the peak intensity ratio P _PO2/CrPO4 are each set within the above-described predetermined range, and from the viewpoint of effectively suppressing the deterioration of the barrier layer 3, the treatment liquid is baked. The heating temperature for forming the barrier layer protective film is preferably about 170 to 250.degree. C., more preferably about 180 to 230.degree. C., still more preferably about 190 to 220.degree. From the same point of view, the baking time is preferably about 2 to 10 seconds, more preferably about 3 to 6 seconds.

From the viewpoint of performing the chemical conversion treatment on the surface of the barrier layer 3 more efficiently, before providing the barrier layer protective films 3a and 3b on the surface of the barrier layer 3, an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid It is preferable to perform the degreasing treatment by a known treatment method such as a washing method or an acid activation method.

[Heat-fusible resin layer 4]
In the all-solid-state battery exterior material 10 of the present disclosure, the heat-fusible resin layer 4 corresponds to the innermost layer, and the heat-fusible resin layers 4 are heat-fused to form a battery element when assembling the all-solid-state battery. It is a layer (sealant layer) that exhibits a sealing function. Examples of the heat-sealing method for heat-sealing the heat-fusible resin layers 4 include bar sealing, hot plate sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, and ultrasonic sealing.

From the viewpoint of making the total thickness residual rate preferably 80% or more and particularly preferably improving the durability in a high-temperature and high-pressure environment, in the all-solid-state battery exterior material 10 of the present disclosure, the heat-fusible resin layer 4 is , polybutylene terephthalate film or polytetrafluoroethylene film. The polybutylene terephthalate film or polytetrafluoroethylene film that forms the heat-sealable resin layer 4 is prepared by laminating a previously prepared polybutylene terephthalate film or polytetrafluoroethylene film with the adhesive layer 5 and heat-sealing it. Alternatively, a resin that forms a polybutylene terephthalate film or a polytetrafluoroethylene film may be melt-extruded to form a film and laminated with the adhesive layer 5 .

The polybutylene terephthalate film preferably further contains an elastomer in addition to polybutylene terephthalate. The elastomer plays a role of increasing the flexibility of the polybutylene terephthalate film while ensuring durability in a high-temperature environment. Preferred elastomers include polytetramethylene glycol. In the polybutylene terephthalate film, the content of the elastomer is not particularly limited as long as it can increase the flexibility while ensuring the durability of the polybutylene terephthalate film in a high temperature environment, for example about 0.1 mass. % or more, preferably about 0.5 mass % or more, more preferably about 1.0 mass % or more, and even more preferably about 3.0 mass % or more. Also, the content is, for example, about 10.0% by mass or less, about 8.0% by mass or less, or about 5.0% by mass or less. Preferred ranges for the content are about 0.1 to 10.0% by mass, about 0.1 to 8.0% by mass, about 0.1 to 5.0% by mass, and 0.5 to 10.0% by mass. %, about 0.5 to 8.0% by mass, about 0.5 to 5.0% by mass, about 1.0 to 10.0% by mass, about 1.0 to 8.0% by mass, 1.0 about 5.0% by mass, about 3.0 to 10.0% by mass, about 3.0 to 8.0% by mass, about 3.0 to 5.0% by mass, and the like.

The heat-fusible resin layer 4 may be formed of only one layer, or may be formed of two or more layers of the same or different resins. When the heat-sealable resin layer 4 is formed of two or more layers, at least one layer is formed of a polybutylene terephthalate film or a polytetrafluoroethylene film, and the polybutylene terephthalate film is the innermost layer. is preferred. When the heat-sealable resin layer 4 is formed of two or more layers, the layer that is not formed of a polybutylene terephthalate film or a polytetrafluoroethylene film is, for example, a polyolefin such as polypropylene or polyethylene, or an acid-modified polypropylene. , or a layer formed of acid-modified polyolefin such as acid-modified polyethylene. However, since polyolefin and acid-modified polyolefin have lower durability in high-temperature environments than polybutylene terephthalate or polytetrafluoroethylene film, the heat-sealable resin layer 4 is made of polybutylene terephthalate film or polytetrafluoroethylene film. It is preferable that it is composed only of a film.

Specific examples of polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymer; homopolypropylene, block copolymer of polypropylene (for example, propylene-α-olefin copolymers; ethylene-butene-propylene terpolymers; and the like. Among these, polypropylene is preferred. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin-based resins may be used alone or in combination of two or more. Acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of polyolefin with an acid component. As the acid-modified polyolefin, the above polyolefin, a copolymer obtained by copolymerizing the above polyolefin with a polar molecule such as acrylic acid or methacrylic acid, or a polymer such as crosslinked polyolefin can be used. Examples of acid components used for acid modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride and itaconic anhydride, and anhydrides thereof.

From the viewpoint of further improving the durability of the all-solid-state battery exterior material 10 in a high-temperature and high-pressure environment, the indentation elastic modulus from the heat-fusible resin layer 4 side of the laminate constituting the exterior material is preferably about 0.3 GPa. Above, more preferably about 0.4 GPa or more, still more preferably about 0.5 GPa or more. From the same point of view, the indentation elastic modulus of the heat-fusible resin layer is preferably about 5 GPa or less, more preferably about 4 GPa or less, even more preferably about 3 GPa or less, still more preferably about 2 GPa or less, still more preferably about 1.5 GPa or less. It is 5 GPa or less. Preferred ranges for the indentation elastic modulus of the heat-fusible resin layer are about 0.3 to 5 GPa, about 0.3 to 4 GPa, about 0.3 to 3 GPa, about 0.3 to 2 GPa, and 0.3 to 1.0 GPa. About 5 GPa, about 0.4 to 5 GPa, about 0.4 to 4 GPa, about 0.4 to 3 GPa, about 0.4 to 2 GPa, about 0.4 to 1.5 GPa, about 0.5 to 5 GPa, 0.5 Up to about 4 GPa, about 0.5 to 2 GPa, and about 0.5 to 1.5 GPa can be mentioned. A method for measuring the indentation elastic modulus of the heat-fusible resin layer is as follows.

[Measurement of indentation modulus]
The indentation elastic modulus of the heat-fusible resin layer conforms to ISO 14577:2015. A method of measuring the indentation elastic modulus using an ultra-micro load hardness tester equipped with a square pyramidal diamond indenter with an angle of 136° is used. Measurement is performed at an indentation speed of 0.1 μm/sec, an indentation depth of 2 μm, a retention time of 5 seconds, and a withdrawal speed of 0.1 μm/sec. The micro-load hardness tester is preferably Picodenter HM500 (manufactured by Fisher Instruments). At least five samples are measured and the average of these measurements is taken as the indentation modulus value for that condition. It is desirable to use a suction table or instant adhesive to fix the sample.

In addition, from the viewpoint of further improving the durability of the all-solid-state battery exterior material 10 in a high-temperature and high-pressure environment, the tensile elongation at break in a 120° C. environment of the heat-fusible resin layer 4 is preferably about 300% or more, more preferably. is about 350% or more, more preferably about 400% or more. From the same point of view, the tensile elongation at break of the heat-fusible resin layer in a 120° C. environment is preferably about 1000% or less, more preferably about 900% or less, and even more preferably about 800% or less. Preferred ranges of the tensile elongation at break of the heat-fusible resin layer in a 120° C. environment are about 300 to 1000%, about 300 to 900%, about 300 to 800%, about 350 to 1000%, and about 350 to 900%. , about 350 to 800%, about 400 to 1000%, about 400 to 900%, and about 400 to 800%. From the same point of view, the tensile elongation at break of the heat-fusible resin layer in a 23° C. environment is preferably about 80% or more, more preferably about 100% or more, and even more preferably about 120% or more. From the same point of view, the tensile elongation at break of the heat-fusible resin layer in a 120° C. environment is preferably about 800% or less, more preferably about 700% or less, and even more preferably about 620% or less. Preferred ranges of the tensile elongation at break of the heat-fusible resin layer in a 23° C. environment are about 80 to 800%, about 80 to 700%, about 80 to 620%, about 100 to 800%, and about 100 to 700%. , about 100 to 620%. The method for measuring the tensile elongation at break of the heat-fusible resin layer is as follows.

[Measurement of Tensile Elongation at Break of Thermal Adhesive Resin Layer]
The tensile elongation at break of the heat-fusible resin layer is measured using a tensile tester (for example, AG-Xplus (trade name) manufactured by Shimadzu Corporation) in accordance with JIS K7127. The test sample width is JIS-K 6251-7 type dumbbell type, the distance between gauge lines is 15 mm, the tensile speed is 300 mm / min, the test environment is 23 ° C. or 120 ° C., respectively, 3 in the direction of MD and TD shall be the average value of times measured. That is, six test samples are prepared and measured, and the average value is obtained.

Further, from the viewpoint of further improving the durability of the all-solid battery exterior material 10 in a high-temperature and high-pressure environment, in the heat-fusible resin layer 4, the tensile breaking strength of the heat-fusible resin layer in a 120 ° C. environment is preferably It is about 10 MPa or higher, more preferably about 15 MPa or higher, and even more preferably about 20 MPa or higher. From the same point of view, the tensile breaking strength of the heat-fusible resin layer in a 120° C. environment is preferably about 70 MPa or less, more preferably about 60 MPa or less, and even more preferably about 50 MPa or less. The preferable range of the tensile breaking strength of the heat-fusible resin layer in a 120° C. environment is preferably about 10 to 70 MPa, more preferably about 10 to 60 MPa, still more preferably about 10 to 50 MPa, preferably about 15 to 70 MPa, More preferably about 15 to 60 MPa, more preferably about 15 to 50 MPa, preferably about 20 to 70 MPa, more preferably about 20 to 60 MPa, still more preferably about 20 to 50 MPa. From the same point of view, the tensile breaking strength of the heat-fusible resin layer in a 23° C. environment is preferably about 20 MPa or more, more preferably about 25 MPa or more, still more preferably about 30 MPa or more, and still more preferably about 40 MPa or more. be. From the same point of view, the tensile breaking strength of the heat-fusible resin layer in a 23° C. environment is preferably about 100 MPa or less, more preferably about 80 MPa or less, and even more preferably about 75 MPa or less. The preferable range of the tensile breaking strength of the heat-fusible resin layer in a 23° C. environment is preferably about 20 to 100 MPa, more preferably about 20 to 80 MPa, still more preferably about 20 to 75 MPa, preferably about 25 to 100 MPa, More preferably about 25 to 80 MPa, more preferably about 25 to 75 MPa, preferably about 30 to 100 MPa, more preferably about 30 to 80 MPa, still more preferably about 30 to 75 MPa, preferably about 40 to 100 MPa, more preferably about 40 Up to about 80 MPa, more preferably about 40 to 75 MPa. The method for measuring the tensile strength at break of the heat-fusible resin layer is as follows.

[Measurement of Tensile Breaking Strength of Thermal Adhesive Resin Layer]
The tensile breaking strength of the heat-fusible resin layer is measured using a tensile tester (for example, AG-Xplus (trade name) manufactured by Shimadzu Corporation) in accordance with JIS K7127. The test sample width is JIS-K 6251-7 type dumbbell type, the distance between gauge lines is 15 mm, the tensile speed is 50 mm / min, the test environment is 23 ° C. or 120 ° C., respectively, 3 in the direction of MD and TD shall be the average value of times measured. That is, six test samples are prepared and measured, and an average value is obtained.

The heat-fusible resin layer 4 may contain a lubricant or the like as necessary. When the heat-fusible resin layer 4 contains a lubricant, the moldability of the exterior material 10 can be enhanced. The lubricant is not particularly limited, and known lubricants can be used. Lubricants may be used singly or in combination of two or more.

The lubricant is not particularly limited, but preferably includes an amide-based lubricant. Specific examples of the lubricant include those exemplified for the base material layer 1 . Lubricants may be used singly or in combination of two or more.

When a lubricant exists on the surface of the heat-sealable resin layer 4, the amount of the lubricant is not particularly limited, but from the viewpoint of improving the moldability of the exterior material, it is preferably about 10 to 50 mg/m ² , more preferably about 10 to 50 mg/m 2 . is about 15 to 40 mg/m ² .

The lubricant present on the surface of the heat-fusible resin layer 4 may be obtained by exuding the lubricant contained in the resin constituting the heat-fusible resin layer 4 . The surface may be coated with a lubricant.

In addition, the thickness of the heat-fusible resin layer 4 is preferably 80% or more of the total thickness residual rate of the all-solid battery exterior material 10, and from the viewpoint of particularly preferably improving the durability in a high-temperature and high-pressure environment. , preferably 30 μm or more, more preferably 40 μm or more, and still more preferably 50 μm or more. The thickness of the heat-fusible resin layer 4 is, for example, about 150 μm or less, preferably about 120 μm or less, and the preferred range is about 30 to 150 μm, about 30 to 120 μm, about 40 to 150 μm, and about 40 to 120 μm. , about 50 to 150 μm, and about 50 to 120 μm.

[Adhesion layer 5]
In the exterior material 10, the adhesive layer 5 is provided between the barrier layer 3 (or the barrier layer protective film 3a if it has a barrier layer protective film 3a) and the heat-fusible resin layer 4 to firmly bond them. layer to be provided.

The total thickness residual rate is preferably 80% or more, and from the viewpoint of particularly preferably improving durability in a high temperature and high pressure environment, the adhesive layer 5 is composed of at least one of polyester and polycarbonate, an alicyclic isocyanate compound and an aromatic It is preferably formed by a cured product of a resin composition containing at least one isocyanate compound.

Preferably, the polyester is a polyester polyol. The polyester polyol is not particularly limited as long as it has an ester bond in its polymer main chain and has a plurality of hydroxyl groups in its terminals or side chains. Also, the polycarbonate is preferably a polycarbonate polyol. The polyester polyol is not particularly limited as long as it has a carbonate bond in the polymer main chain and a plurality of hydroxyl groups in the terminals or side chains. Each of the polyester and polycarbonate contained in the resin composition forming the adhesive layer 5 may be of one kind, or may be of two or more kinds.

The alicyclic isocyanate compound is not particularly limited as long as it is a compound having an alicyclic structure and an isocyanate group. The alicyclic isocyanate compound preferably has two or more isocyanate groups. Specific examples of the alicyclic isocyanate compound include isophorone diisocyanate (IPDI) and the like, polymers and nurates thereof, mixtures thereof and copolymers with other polymers. In addition, adducts, burettes, isocyanurates and the like are included. The number of alicyclic isocyanate compounds contained in the resin composition forming the adhesive layer 5 may be one, or two or more.

Moreover, the aromatic isocyanate compound is not particularly limited as long as it is a compound having an aromatic ring and an isocyanate group. The aromatic isocyanate compound preferably has two or more isocyanate groups. Specific examples of aromatic isocyanate compounds include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymers and nurates thereof, mixtures thereof and copolymers with other polymers. In addition, adducts, burettes, isocyanurates and the like are included. The number of aromatic isocyanate compounds contained in the resin composition forming the adhesive layer 5 may be one, or two or more.

When the resin composition forming the adhesive layer 5 contains at least one of an alicyclic isocyanate compound and an aromatic isocyanate compound, for example, the alicyclic isocyanate compound may be contained and the aromatic isocyanate compound may not be contained. However, for example, an aromatic isocyanate compound may be included without an alicyclic isocyanate compound, or both an alicyclic isocyanate compound and an aromatic isocyanate compound may be included.

The content of the alicyclic isocyanate compound and the aromatic isocyanate compound in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass in the resin composition constituting the adhesive layer 5. It is more preferably in the range of 0.5 to 40% by mass. Further, when the adhesive layer 5 contains both an alicyclic isocyanate compound and an aromatic isocyanate compound, the total content of these in the resin composition constituting the adhesive layer 5 is in the range of 0.1 to 50% by mass. preferably in the range of 0.5 to 40% by mass.

The thickness of the adhesive layer 5 is preferably about 50 μm from the viewpoint of preferably making the total thickness residual rate of the all-solid battery exterior material 10 80% or more and particularly preferably improving the durability in a high-temperature and high-pressure environment. Below, about 40 μm or less, about 30 μm or less, about 20 μm or less, about 5 μm or less, and preferably about 0.1 μm or more and about 0.5 μm or more are mentioned. is about 0.1 to 50 μm, about 0.1 to 40 μm, about 0.1 to 30 μm, about 0.1 to 20 μm, about 0.1 to 5 μm, about 0.5 to 50 μm, about 0.5 to 40 μm , about 0.5 to 30 μm, about 0.5 to 20 μm, and about 0.5 to 5 μm.

[Surface coating layer 6]
The exterior material 10 is provided on the substrate layer 1 of the laminate (opposite to the barrier layer 3 of the substrate layer 1) as necessary for the purpose of improving at least one of designability, scratch resistance, moldability, etc. side) may be provided with a surface coating layer 6 . The surface coating layer 6 is a layer positioned on the outermost layer side of the exterior material 10 when the all-solid-state battery is assembled using the exterior material 10 .

The surface coating layer 6 can be formed of resin such as polyvinylidene chloride, polyester, polyurethane, acrylic resin, and epoxy resin, for example.

When the resin forming the surface coating layer 6 is a curable resin, the resin may be either a one-component curable type or a two-component curable type, preferably the two-component curable type. Examples of the two-liquid curing resin include two-liquid curing polyurethane, two-liquid curing polyester, and two-liquid curing epoxy resin. Among these, two-liquid curable polyurethane is preferred.

Examples of two-liquid curable polyurethanes include polyurethanes containing a first agent containing a polyol compound and a second agent containing an isocyanate compound. Preferred examples include a two-component curing type polyurethane in which a polyol such as polyester polyol, polyether polyol, or acrylic polyol is used as the first agent and an aromatic or aliphatic polyisocyanate is used as the second agent. Examples of polyurethane include polyurethane containing a polyurethane compound obtained by reacting a polyol compound and an isocyanate compound in advance and an isocyanate compound. Examples of polyurethane include polyurethane containing a polyurethane compound obtained by reacting a polyol compound and an isocyanate compound in advance and a polyol compound. Examples of polyurethanes include polyurethanes obtained by reacting a polyurethane compound obtained by reacting a polyol compound and an isocyanate compound in advance with moisture in the air and the like to cure the compound. As the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group in a side chain in addition to the terminal hydroxyl group of the repeating unit. Examples of the second agent include aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds. Examples of isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), and diphenylmethane diisocyanate. (MDI), naphthalene diisocyanate (NDI), and the like. In addition, polyfunctional isocyanate-modified products of one or more of these diisocyanates are also included. Moreover, a polymer (for example, a trimer) can also be used as a polyisocyanate compound. Such multimers include adducts, biurets, nurates and the like. In addition, the aliphatic isocyanate compound refers to an isocyanate having an aliphatic group and no aromatic ring, and the alicyclic isocyanate compound refers to an isocyanate having an alicyclic hydrocarbon group, and the aromatic isocyanate compound refers to an isocyanate having an aromatic ring.

At least one of the surface and the inside of the surface coating layer 6 may be coated with the above-described lubricant or anti-rust agent as necessary depending on the functionality to be provided on the surface coating layer 6 and its surface. Additives such as blocking agents, matting agents, flame retardants, antioxidants, tackifiers and antistatic agents may be included. Examples of the additive include fine particles having an average particle size of about 0.5 nm to 5 μm. The average particle size of the additive is the median size measured with a laser diffraction/scattering particle size distribution analyzer.

Additives may be either inorganic or organic. Also, the shape of the additive is not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, scale-like, and the like.

Specific examples of additives include talc, silica, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, and antimony oxide. , titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotube, high melting point nylon, acrylate resin, Crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel, and the like. Additives may be used singly or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferred from the viewpoint of dispersion stability and cost. In addition, the additive may be subjected to various surface treatments such as insulation treatment and high-dispersion treatment.

A method for forming the surface coating layer 6 is not particularly limited, and an example thereof includes a method of applying a resin for forming the surface coating layer 6 . When adding additives to the surface coating layer 6, a resin mixed with the additives may be applied.

The thickness of the surface coating layer 6 is not particularly limited as long as it exhibits the above functions as the surface coating layer 6, and is, for example, approximately 0.5 to 10 μm, preferably approximately 1 to 5 μm.

The method for manufacturing the exterior material 10 is not particularly limited as long as a laminate obtained by laminating each layer included in the exterior material 10 is obtained. are laminated in this order.

An example of a method for manufacturing the exterior material 10 is as follows. First, a layered body (hereinafter also referred to as "layered body A") is formed by laminating a substrate layer 1, an adhesive layer 2, and a barrier layer 3 in this order. Specifically, the laminate A is formed by coating the base layer 1 or the barrier layer 3 with the adhesive used for forming the adhesive layer 2 by a coating method such as gravure coating or roll coating. , after drying, the barrier layer 3 or the substrate layer 1 is laminated and the adhesive layer 2 is cured by a dry lamination method.

Next, on the barrier layer 3 of the laminate A, the heat-fusible resin layer 4 is laminated. When the heat-fusible resin layer 4 is directly laminated on the barrier layer 3, the resin component constituting the heat-fusible resin layer 4 is applied onto the barrier layer 3 of the laminate A by a gravure coating method or a roll coating method. It may be applied by a method such as When the adhesive layer 5 is provided between the barrier layer 3 and the heat-fusible resin layer 4, for example, (1) the adhesive layer 5 and the heat-fusible resin layer are placed on the barrier layer 3 of the laminate A. 4 (co-extrusion lamination method); (3) a method of extruding or solution-coating an adhesive for forming an adhesive layer 5 on the barrier layer 3 of the laminate A, followed by drying and baking at a high temperature; (4) The barrier layer 3 of the laminate A and the barrier layer 3 of the laminated body A, which is laminated in advance in a sheet form A method of laminating the laminate A and the heat-fusible resin layer 4 via the adhesive layer 5 while pouring the melted adhesive layer 5 between the formed heat-fusible resin layer 4 (sandwich lamination method). etc.

When providing the surface coating layer 6 , the surface coating layer 6 is laminated on the surface of the substrate layer 1 opposite to the barrier layer 3 . The surface coating layer 6 can be formed, for example, by coating the surface of the substrate layer 1 with the above-described resin for forming the surface coating layer 6 . The order of the step of laminating the barrier layer 3 on the surface of the base material layer 1 and the step of laminating the surface coating layer 6 on the surface of the base material layer 1 is not particularly limited. For example, after forming the surface coating layer 6 on the surface of the substrate layer 1 , the barrier layer 3 may be formed on the surface of the substrate layer 1 opposite to the surface coating layer 6 .

As described above, surface coating layer 6 provided as required/base material layer 1/adhesive layer 2 provided as required/barrier layer protective film 3b provided as required/barrier layer 3/required A laminated body comprising barrier layer protective film 3a/adhesive layer 5/heat-fusible resin layer 4 provided in accordance with the requirements is formed in this order. In order to strengthen the properties, it may be further subjected to heat treatment such as hot roll contact type, hot air type, near-infrared type or far-infrared type. Conditions for such heat treatment include, for example, about 150 to 250° C. for about 1 to 5 minutes.

In order to improve or stabilize film formability, lamination processing, final product secondary processing (pouching, embossing) aptitude, etc., each layer constituting the exterior material 10 may be subjected to corona treatment, blasting, etc., as necessary. Surface activation treatment such as treatment, oxidation treatment, and ozone treatment may be applied. For example, by subjecting at least one surface of the substrate layer 1 to corona treatment, it is possible to improve or stabilize film formability, lamination processing, final product secondary processing suitability, and the like. Further, for example, the printability of the ink onto the surface of the base material layer 1 can be improved by applying a corona treatment to the surface of the base material layer 1 opposite to the barrier layer 3 .

EXAMPLES The present disclosure will be described in detail below with reference to examples and comparative examples. However, the present disclosure is not limited to the examples.

[Example 1]
A polyethylene terephthalate film (25 μm) was prepared as a base layer. Also, an aluminum alloy foil (JIS H4160:1994 A8021H-O, thickness 40 μm) was prepared as a barrier layer. Both sides of the aluminum foil are chemically treated. In the chemical conversion treatment of the aluminum foil, a treatment solution consisting of phenolic resin, fluorochromium compound, and phosphoric acid was applied to both sides of the aluminum foil by a roll coating method so that the coating amount of chromium was 10 mg/m ² (dry mass). It was carried out by coating and baking. A polybutylene terephthalate film (thickness: 50 μm) containing 3.5% by mass of an elastomer (polytetramethylene glycol) was prepared as a heat-fusible resin layer.

Using a two-liquid curing urethane adhesive (polyol compound and aromatic isocyanate compound), the substrate layer and the barrier layer are adhered by a dry lamination method to form a substrate layer (25 μm)/adhesive layer (4 μm)/barrier. A stack of layers (40 μm) was made. Next, using a two-component curable urethane adhesive (polyol compound and alicyclic isocyanate compound (including isophorone diisocyanate)), the barrier layer side of the laminate obtained by a dry lamination method, and the heat-sealable An adhesive layer (4 μm)/a heat-fusible resin layer (40 μm) was laminated on the barrier layer. Next, the resulting laminate is aged and heated to form a substrate layer (polyethylene terephthalate film (25 μm))/adhesive layer (cured two-liquid curable urethane adhesive (4 μm))/barrier layer. (Aluminum alloy foil (40 μm))/adhesive layer (hardened two-component urethane adhesive (4 μm))/heat-fusible resin layer (polybutylene terephthalate film (50 μm) containing elastomer) are laminated in this order. An exterior material composed of a laminated body was obtained.

[Example 2]
A base layer ( Polyethylene terephthalate film (25 μm)) / adhesive layer (cured product of two-component curable urethane adhesive (4 μm)) / barrier layer (aluminum alloy foil (40 μm)) / adhesive layer (curing of two-component curable urethane adhesive (4 μm))/heat-fusible resin layer (polybutylene terephthalate film (50 μm) containing elastomer) laminated in this order to obtain an exterior material.

[Example 3]
Substrate layer (polyethylene terephthalate film (25 μm))/adhesive in the same manner as in Example 1, except that an elastomer-free polybutylene terephthalate film (thickness: 50 μm) was used as the heat-fusible resin layer. Layer (cured product of 2-component curable urethane adhesive (4 μm))/barrier layer (aluminum alloy foil (40 µm))/adhesive layer (cured product of 2-component curable urethane adhesive (4 μm))/heat fusion An exterior material comprising a laminate in which resin layers (polybutylene terephthalate film (50 μm) containing no elastomer) were laminated in this order was obtained.

[Example 4]
A base material layer (polyethylene terephthalate Film (25 μm)) / adhesive layer (cured product of two-component curable urethane adhesive (4 μm)) / barrier layer (aluminum alloy foil (40 μm)) / adhesive layer (cured product of two-component curable urethane adhesive ( 4 μm))/heat-fusible resin layer (polybutylene terephthalate film (100 μm) containing elastomer) laminated in this order to obtain an exterior material.

[Example 5]
A polybutylene terephthalate film (thickness: 100 μm) containing 3.5% by mass of elastomer (polytetramethylene glycol) is used as the heat-fusible resin layer, and the barrier layer and the heat-fusible resin layer are bonded together. In the formation of the adhesive layer, the substrate layer (polyethylene terephthalate film ( 25 μm)) / adhesive layer (cured product of two-component curable urethane adhesive (4 μm)) / barrier layer (aluminum alloy foil (40 μm)) / adhesive layer (cured product of two-component curable urethane adhesive (4 μm) )/heat-fusible resin layer (polybutylene terephthalate film (100 μm) containing elastomer) laminated in this order to obtain an exterior material.

[Comparative Example 1]
Substrate layer (polyethylene terephthalate film (25 μm))/adhesive layer (2 liquid Cured product of curable urethane adhesive (4 μm)) / barrier layer (aluminum alloy foil (40 μm)) / adhesive layer (cured product of two-component curable urethane adhesive (4 μm)) / heat-fusible resin layer (not An exterior material comprising a laminate in which stretched polypropylene films (CPP (40 μm)) were laminated in this order was obtained.

[Measurement of elastomer content]
The elastomer content in the polybutylene terephthalate films used in Examples and Comparative Examples was measured by the following measuring method. The heat-fusible resin layer (polybutylene terephthalate film) was peeled off from the laminate constituting the exterior material. The resulting polybutylene terephthalate film was cut into approximately 55 mg test samples. Next, the test sample was placed in a screw vial, and 0.5 mL of deuterated chloroform and 0.5 mL of HFIP solvent were added using a micropipettor to fully dissolve the test sample. The dissolved test sample was transferred to an NMR sample tube to measure the elastomer content in the polybutylene terephthalate film. The measurement equipment and measurement conditions are as follows.

<Measurement equipment/measurement conditions>
・Apparatus: NMR AVANCE 400MHz made by Bruker Japan ・Probe: PA DUL 400S1 C-H-D05 Z BTO PLUS made by Bruker Japan ・Measurement nucleus: 1H
・ Solvent: HFIP (1,1,1,3,3,3-hexafluoro-2-propanol) / CDCl ₃ mixed solvent ・ Sample amount: 55 mg / 1 mL (solvent)
・Measurement temperature: Room temperature ・Number of integration times: ¹ H/64 times ・Waiting time: ¹ H/5 s
・Window function: exponential

[Measurement of tensile elongation at break]
The tensile elongation at break was measured for each of the laminate constituting the exterior material, the polybutylene terephthalate film (PBT) used for forming the heat-fusible resin layer, and the unstretched polypropylene film (CPP). The measurement was performed using a tensile tester (AG-Xplus (trade name) manufactured by Shimadzu Corporation) in accordance with JIS K7127. The test sample width is JIS-K 6251-7 type dumbbell type, the distance between gauge lines is 15 mm, the tensile speed is 300 mm / min, the test environment is 23 ° C. or 120 ° C., respectively, 3 in the direction of MD and TD The average value of the measurements was taken. That is, in each example and comparative example, six test samples were prepared and measured, and the average value was obtained. Table 1 shows the results.

[Measurement of indentation modulus]
The laminate was cut out, and the indentation elastic modulus was measured from the heat-sealable resin layer side. The indentation modulus of elasticity was measured in accordance with ISO 14577:2015, in an environment of about 23°C and about 60% RH, against the surface of the heat-sealable resin layer of the laminate. A method of measuring the indentation elastic modulus using an ultra-micro load hardness tester equipped with a diamond indenter was used. The measurement was performed at an indentation speed of 0.1 μm/sec, an indentation depth of 2 μm, a holding time of 5 seconds, and a withdrawal speed of 0.1 μm/sec. Pico Dentor HM500 (manufactured by Fischer Instruments) was used as the ultra-micro load hardness tester. At least five samples were measured and the average of these measurements was taken as the indentation modulus value for that condition. An adsorption table was used to fix the sample. Table 1 shows the results.

[Measurement of tensile breaking strength]
The tensile strength at break was measured for each of the laminate constituting the exterior material, the polybutylene terephthalate film (PBT) used for forming the heat-fusible resin layer, and the unstretched polypropylene film (CPP). The tensile strength at break was measured using a tensile tester (AG-Xplus (trade name) manufactured by Shimadzu Corporation) in accordance with JIS K7127. The test sample width is JIS-K 6251-7 type dumbbell type, the distance between gauge lines is 15 mm, the tensile speed is 50 mm / min, the test environment is 23 ° C. or 120 ° C., respectively, 3 in the direction of MD and TD The average value of the measurements was taken. That is, in each example and comparative example, six test samples were prepared and measured, and the average value was obtained. Table 1 shows the results.

[Measurement of thickness residual ratio]
Regarding the laminate constituting the exterior material, the residual thickness ratio between the adhesive layer and the heat-fusible resin layer was measured according to the following measurement conditions. Table 1 shows the results. The all-solid-state battery exterior material was cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample was measured and used as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and the measurement samples are restrained from both sides. A pressure of 100 MPa was applied using a jig, and in this state, it was placed in an oven at 120° C. and stored for 6 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample was measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressing was measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness was calculated as the residual ratio of the total thickness. The residual ratio of the total thickness was the average value of two measurement samples. The thickness is measured by cutting the measurement sample in the thickness direction using a microtome (manufactured by Yamato Koki Kogyo: REM-710 Ritratome), and observing the resulting cross section with a laser microscope (manufactured by Keyence: VK-9700). gone.

[Evaluation of insulating properties (stored at 120°C for 6 hours)]
As shown in FIG. 7, the all-solid-state battery laminate 10 was cut into two pieces of 30 mm square, and a stainless steel plate (SUS plate) 90 of 26 mm square was placed between them so that the heat-sealable resin layer side was in contact with them. At this time, a metal wire 100 having a diameter of 25 μm was sandwiched between the laminated body 10 and the SUS plate 90, and while being pressurized to 100 MPa by the restraining jig 80, it was placed in an oven at 120° C. and stored for 6 hours. A cushioning material was inserted between the restraining jig and the laminate so that a uniform pressure was applied. It was confirmed whether the metal wire was in contact with the barrier layer after performing the thermocompression test. Whether or not the metal wire was in contact with the barrier layer after the thermocompression test was performed was obtained by cutting the sample after the test in the thickness direction using a microtome (manufactured by Yamato Koki Kogyo Co., Ltd.: REM-710 Litratome). The cross section was observed with a laser microscope (manufactured by Keyence: VK-9700).
Insulation evaluation criteria are as follows. If the barrier layer and the metal wire are in contact with each other, it indicates that a short circuit is likely to occur. Table 1 shows the results.
A: The barrier layer and the metal wire are not in contact.
C: The barrier layer and the metal wire are in contact.

[Evaluation of insulation (stored at 120°C for 24 hours)]
In the measurement conditions of [Evaluation of insulation (stored at 120 ° C. for 6 hours)], instead of "put in an oven at 120 ° C. and store for 6 hours", instead of "put in an oven at 120 ° C. and store for 24 hours Evaluation was performed in the same manner as in [Evaluation of insulating properties (storage at 120° C. for 6 hours)] except for the above. Table 1 shows the results.

[Repeated Tensile Properties of Laminate]
The repeated tensile properties of the laminate constituting the exterior material were evaluated. It was measured using a tensile tester (AG-Xplus (trade name) manufactured by Shimadzu Corporation) in accordance with JIS K7127. The test sample width was a dumbbell type of JIS-K 6251-7 type, the distance between gauge lines was 15 mm, the tensile speed was 50 mm/min, and the test environment was 120°C. After pulling the test piece by 15 mm at 120°C, the test piece was returned to room temperature, pulled again at 120°C by 20 mm, and returned to room temperature. Further, pulling 20 mm at 120° C. and returning to room temperature were repeated until the film was broken. When the test piece was reinstalled, the distance was adjusted so that the strength was zero. Table 1 shows the results.

In Table 1, "not detectable" for tensile strength at break and "1000<" for tensile elongation at break mean that the test sample did not break even when pulled to the limit of the tensile tester.

As described above, the present disclosure provides inventions in the following aspects.
Section 1. An exterior material for an all-solid-state battery, which is composed of a laminate including at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside,
An exterior material for an all-solid-state battery, wherein the residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 80% or more.
<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraint jig, and in this state, it is placed in an oven at 120° C. and stored for 6 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples.
Section 2. An exterior material for an all-solid-state battery, which is composed of a laminate including at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside,
An exterior material for an all-solid-state battery, wherein the residual ratio of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 40% or more.
<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraining jig, and in this state, it is placed in an oven at 120° C. and stored for 24 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples.
Item 3. Item 3. The exterior material for an all-solid-state battery according to Item 1 or 2, wherein the laminate has an indentation elastic modulus of 0.3 GPa or more from the heat-fusible resin layer side.
Section 4. 4. The exterior material for an all-solid-state battery according to any one of items 1 to 3, wherein the heat-sealable resin has a tensile elongation at break of 500% or more in a 120°C environment.
Item 5. Item 5. The all-solid-state battery packaging material according to any one of items 1 to 4, wherein the laminate constituting the all-solid-state battery packaging material has a tensile breaking strength of 6 MPa or more in a 120° C. environment.
Item 6. Any one of Items 1 to 5, wherein the adhesive layer is formed from a cured product of a resin composition containing at least one of polyester and polycarbonate and at least one of an alicyclic isocyanate compound and an aromatic isocyanate compound. 2. The exterior material for an all-solid-state battery according to .
Item 7. Item 7. The exterior material for an all-solid-state battery according to any one of Items 1 to 6, wherein the base material layer contains at least one of polyamide and polyester.
Item 8. A battery element including at least a unit cell including a positive electrode active material layer, a negative electrode active material layer, and a solid electrolyte layer laminated between the positive electrode active material layer and the negative electrode active material layer is an exterior for an all-solid battery. An all-solid-state battery housed in a package formed of a material,
The all-solid-state battery exterior material is an all-solid-state battery exterior material composed of a laminate including at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside,
An all-solid-state battery, wherein the residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 80% or more.
<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraint jig, and in this state, it is placed in an oven at 120° C. and stored for 6 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples.
Item 9. A step of obtaining a laminate by laminating at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside,
A method for producing an exterior material for an all-solid-state battery, wherein the residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 80% or more.
<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraint jig, and in this state, it is placed in an oven at 120° C. and stored for 6 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples.

1 Base layer 2 Adhesive layer 3 Barrier layers 3a, 3b Barrier layer protective film 4 Thermal adhesive resin layer 5 Adhesive layer 6 Surface coating layer 10 Exterior material for all-solid battery 20 Negative electrode layer 21 Negative electrode active material layer 22 Negative electrode collection Electric body 30 Positive electrode layer 31 Positive electrode active material layer 32 Positive electrode current collector 40 Solid electrolyte layer 50 Unit cell 60 Terminal 70 All-solid battery 80 Restraining jig 90 Stainless steel plate 100 Metal wire

Claims (8)

An exterior material for an all-solid-state battery, which is composed of a laminate including at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside,
The heat-sealable resin layer is formed of a polybutylene terephthalate film containing polytetramethylene glycol ,
The adhesive layer is formed of a cured product of a resin composition containing a polyester polyol and at least one of an alicyclic isocyanate compound and an aromatic isocyanate compound,
An exterior material for an all-solid-state battery, wherein the residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 80% or more.
<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraint jig, and in this state, it is placed in an oven at 120° C. and stored for 6 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples. An exterior material for an all-solid-state battery, which is composed of a laminate including at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside,
The heat-sealable resin layer is formed of a polybutylene terephthalate film containing polytetramethylene glycol ,
The adhesive layer is formed of a cured product of a resin composition containing a polyester polyol and at least one of an alicyclic isocyanate compound and an aromatic isocyanate compound,
An exterior material for an all-solid-state battery, wherein the residual ratio of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 40% or more.
<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraining jig, and in this state, it is placed in an oven at 120° C. and stored for 24 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples. 3. The exterior material for an all-solid-state battery according to claim 1, wherein said laminate has an indentation elastic modulus of 0.3 GPa or more from said heat-fusible resin layer side. The exterior material for an all-solid-state battery according to any one of claims 1 to 3, wherein the thermal adhesive resin has a tensile elongation at break of 500% or more in a 120°C environment. The all-solid-state battery packaging material according to any one of claims 1 to 4, wherein the laminate constituting the all-solid-state battery packaging material has a tensile breaking strength of 6 MPa or more in a 120°C environment. The exterior material for an all-solid-state battery according to any one of claims 1 to 5, wherein the base material layer contains at least one of polyamide and polyester. A battery element including at least a unit cell including a positive electrode active material layer, a negative electrode active material layer, and a solid electrolyte layer laminated between the positive electrode active material layer and the negative electrode active material layer is an exterior for an all-solid battery. An all-solid-state battery housed in a package formed of a material,
The all-solid-state battery exterior material is an all-solid-state battery exterior material composed of a laminate including at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside,
The heat-sealable resin layer is formed of a polybutylene terephthalate film containing polytetramethylene glycol ,
The adhesive layer is formed of a cured product of a resin composition containing a polyester polyol and at least one of an alicyclic isocyanate compound and an aromatic isocyanate compound,
An all-solid-state battery, wherein the residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 80% or more.
<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraint jig, and in this state, it is placed in an oven at 120° C. and stored for 6 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples. A step of obtaining a laminate by laminating at least a substrate layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer in this order from the outside,
The heat-sealable resin layer is formed of a polybutylene terephthalate film containing polytetramethylene glycol ,
The adhesive layer is formed of a cured product of a resin composition containing a polyester polyol and at least one of an alicyclic isocyanate compound and an aromatic isocyanate compound,
A method for producing an exterior material for an all-solid-state battery, wherein the residual rate of the total thickness of the adhesive layer and the heat-fusible resin layer measured under the following measurement conditions is 80% or more.
<Measurement conditions>
The all-solid-state battery exterior material is cut into 30 mm squares and used as measurement samples. The total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as a reference total thickness. Next, a 26 mm square stainless steel plate is placed between the two measurement samples so that the heat-fusible resin layers of the two measurement samples face each other, and from both sides of the measurement samples, A pressure of 100 MPa is applied using a restraint jig, and in this state, it is placed in an oven at 120° C. and stored for 6 hours. After taking out from the oven, the total thickness of the adhesive layer and the heat-fusible resin layer of the measurement sample is measured and taken as the total thickness after heating and pressurization. The total thickness after heating and pressurization is measured for corners formed by pressing the stainless steel plate into the measurement sample. The ratio of the total thickness after heating and pressurization to the reference thickness is calculated as the residual ratio of the total thickness. The residual ratio of the total thickness is the average value of the two measurement samples.

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