JP5779815B2 - Battery cell - Google Patents

Description

  The present invention relates to a battery cell.

  A battery cell such as a lithium ion secondary battery is used as a power supply source in various devices such as a mobile device such as a mobile phone and a mobile device such as an automobile. Battery cells are expected to improve flexibility and durability.

  The battery cell has a pair of electrodes and an electrolyte layer held between the pair of electrodes. When water vapor, oxygen gas, or the like enters the battery cell, the electrode or the electrolyte layer deteriorates, leading to a decrease in battery cell performance or a shortened life. In order to improve the durability of a battery cell, a technique for providing a battery cell with a barrier film having gas barrier properties has been proposed (for example, Patent Document 1).

  The exterior body for a lithium ion battery of Patent Document 1 has a barrier laminated film in which a vapor deposition thin film layer of aluminum oxide, a gas barrier coating layer, a vapor deposition thin film layer of aluminum oxide, and a gas barrier coating layer are sequentially laminated on one surface of a polyester film. doing. A nylon film is laminated on the gas barrier coating layer surface outside the laminated film. A sealant layer is laminated on the other polyester film surface.

JP 2005-19077 A

  In general, an organic material barrier film has higher flexibility than an inorganic material barrier film, but it is difficult to improve gas barrier properties. When the barrier film of an inorganic material passes through a bent state, the gas barrier property may be remarkably lowered. As described above, the conventional battery cell may have insufficient gas barrier properties in taking advantage of flexibility, and there is a possibility of performance degradation and shortened life due to insufficient gas barrier properties. The present invention has been made in view of the above circumstances, and an object thereof is to achieve both high flexibility and high gas barrier properties in a battery cell.

The battery cell according to the first aspect of the present invention is disposed on the opposite side of the electrolyte layer with respect to one electrode of the pair of electrodes, the electrolyte layer disposed between the pair of electrodes, and one electrode of the pair of electrodes. A barrier film having one or more thin film layers, wherein at least one of the thin film layers contains silicon, oxygen, and carbon, and the layer in the film thickness direction of the thin film layer The distance from the surface, the ratio of the amount of silicon atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms (atom ratio of silicon), the ratio of the amount of oxygen atoms (the atomic ratio of oxygen) and the ratio of the amount of carbon atoms In the silicon distribution curve, oxygen distribution curve, and carbon distribution curve showing the relationship with (atom ratio of carbon), the following conditions (i) to (iii): (i) The carbon distribution curve is substantially continuous. (Ii) the carbon distribution curve has at least one extreme value (Iii) the absolute value of the difference between the maximum value and the minimum value of the atomic ratio of carbon in the carbon distribution curve is 5 at% or more, and the carbon distribution curve is 2 in the thin film layer. Has more than one extreme value.

  In at least one of the thin film layers, the battery cell according to the first aspect has an electron beam transmittance curve indicating a relationship between a distance from the surface of the layer in the film thickness direction of the layer and an electron beam transmittance. The aspect which has at least 1 extreme value may be sufficient.

  The battery cell according to the first aspect may be an aspect in which the carbon distribution curve has a maximum value and a minimum value.

  The battery cell according to the first aspect may be an aspect in which the absolute value of the difference between the maximum value and the minimum value of the atomic ratio of silicon in the silicon distribution curve is less than 5 at%.

  The battery cell according to the second aspect is disposed on the opposite side of the electrolyte layer with respect to one electrode of the pair of electrodes, the electrolyte layer disposed between the pair of electrodes, and one electrode of the pair of electrodes. An electron beam showing the relationship between the distance from the surface of the layer in the film thickness direction of the layer and the electron beam transmittance in at least one of the thin film layers. The transmission curve has at least one extreme value.

In the battery cells of the first and second aspects, the roughness of the surface on the one electrode side of the barrier film is the following condition (iv):
(Iv) Rmax <200 nm, where Rmax is the maximum surface height,
The aspect which satisfy | fills may be sufficient.

The battery cell of the first and second aspects includes a base material disposed on the opposite side of the electrolyte layer with respect to one electrode of the pair of electrodes,
The aspect in which the said barrier film is formed in the said base material may be sufficient.

  The battery cell of the 1st, 2nd aspect may be the aspect by which the said barrier film is formed in each of both surfaces of the said base material.

In the battery cells of the first and second aspects, a pair of base materials are arranged so as to sandwich the pair of electrodes, and the barrier film is formed on each of the pair of base materials,
One electrode of the pair of electrodes is formed on one substrate of the pair of substrates, and the other substrate of the pair of substrates on the other electrode of the pair of electrodes May be an embodiment in which is adhered.

  The battery cell of the first and second aspects may be an aspect in which the electrolyte layer is formed of a non-aqueous electrolyte.

  According to the present invention, both high flexibility and high gas barrier properties can be achieved in the battery cell.

(A) is a schematic diagram which shows the structural example of the battery cell which concerns on this invention, (b) is the sectional view on the A-A 'line of Fig.1 (a). It is a figure which shows the structural example of the manufacturing apparatus of a barrier film. (A) is an image which shows the cross section of the barrier film of Example 1, (b) is a graph which shows the electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film of Example 1. 4 is a graph showing an atomic ratio distribution in the barrier film of Example 1. (A) is an image which shows the cross section of the barrier film of Example 2, (b) is a graph which shows the electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film of Example 2. 6 is a graph showing the distribution of atomic ratios in the barrier film of Example 2. 10 is a graph showing the distribution of atomic ratios in the barrier film of Example 3. (A) is an image showing a cross section of the barrier film of Comparative Example 1, and (b) is a graph showing electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film of Comparative Example 1. 6 is a graph showing the distribution of atomic ratios in the barrier film of Comparative Example 1. (A) is an image which shows the cross section of the barrier film of the comparative example 2, (b) is a graph which shows the electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film of the comparative example 2. 10 is a graph showing an atomic ratio distribution in the barrier film of Comparative Example 2. (A) is an image showing a cross section of the barrier film of Comparative Example 3, and (b) is a graph showing electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film of Comparative Example 3. (A)-(d) is a figure which shows the example of a structure of the device to which the battery cell which concerns on this invention is applied, respectively.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In the following description, the same components are denoted by the same reference numerals, and redundant description may be omitted.

Fig.1 (a) is a schematic diagram which shows the structural example of the battery cell based on this invention, FIG.1 (b) is the sectional view on the AA 'line of Fig.1 (a).
The battery cell according to the present embodiment is a secondary battery that can be repeatedly charged and discharged. The battery cell according to the present embodiment can be used as a power supply source in various devices such as a portable device such as a mobile phone and a mobile device such as an automobile, and as a power buffer of a power generation device. Here, an example in which the present invention is applied to a film-type lithium ion secondary battery will be described. The present invention can be applied to various secondary batteries such as a sodium secondary battery, various primary batteries, and the like in addition to the lithium ion secondary battery.

  A battery cell 1 shown in FIGS. 1A and 1B includes an electrode body 2, a current collector 3, a current collector 4, a laminated film 5, a laminated film 6, and a sealing material 7. The electrode body 2 includes a pair of electrodes (a positive electrode active material layer 8 and a negative electrode active material layer 9) and an electrolyte layer 10. The laminated film 5 includes a base material 11 and a barrier film 12. The laminated film 6 includes a base material 13 and a barrier film 14.

  The electrode body 2 of the present embodiment is a thin plate-like or film-like laminate. A laminated film 5 is disposed on one surface side of the electrode body 2, and a laminated film 6 is disposed on the other surface side of the electrode body 2. The current collector 3 is disposed between the electrode body 2 and the laminated film 5. The current collector 4 is disposed between the electrode body 2 and the laminated film 6. The sealing material 7 is disposed between the laminated film 5 and the laminated film 6 so as to surround the outer periphery of the electrode body 2 in an annular shape. The electrode body 2 is hermetically sealed in a space surrounded by the laminated film 5, the laminated film 6, and the sealing material 7.

  In the electrode body 2, the positive electrode active material layer 8 and the negative electrode active material layer 9 are spaced apart so as not to be in direct contact with each other. The electrolyte layer 10 is disposed between the positive electrode active material layer 8 and the negative electrode active material layer 9. The positive electrode active material layer 8 is in contact with the current collector 3 and is electrically connected to the current collector 3. The negative electrode active material layer 9 is in contact with the current collector 4 and is electrically connected to the current collector 4.

  The laminated film 5 has a structure in which a barrier film 12 is formed on a film-like substrate 11. The laminated film 5 is disposed with the surface on which the barrier film 12 is formed facing the electrode body 2. The laminated film 6 has a structure in which a barrier film 14 is formed on a film-like substrate 13. The laminated film 6 is disposed with the surface on which the barrier film 14 is formed facing the electrode body 2.

  The battery cell 1 generally operates as follows. When the battery cell 1 is charged, electrons are supplied from the current collector 4 to the negative electrode active material layer 9 and lithium ions are taken into the negative electrode active material layer 9 from the electrolyte layer 10. Further, when the battery cell 1 is charged, lithium ions are released from the positive electrode active material layer 8 into the electrolyte layer 10, and electrons are released from the positive electrode active material layer 8 to the current collector 3. When the battery cell 1 is discharged, lithium ions are released from the negative electrode active material layer 9 into the electrolyte layer 10, and electrons are released from the negative electrode active material layer 9 to the current collector 4. Further, when the battery cell 1 is discharged, electrons are supplied from the current collector 3 to the positive electrode active material layer 8, and lithium ions are taken into the positive electrode active material layer 8 from the electrolyte layer 10.

Next, each component of the battery cell 1 will be described in detail.
The current collectors 3 and 4 are, for example, a thin metal plate or a metal foil. The current collector 3 is formed on the barrier film 12 of the laminated film 5. The current collector 4 is formed on the barrier film 14 of the laminated film 6. The material of the current collector 3 may be the same as or different from the material of the current collector 4. Examples of the material for forming the current collectors 3 and 4 include metal materials such as gold, copper, nickel, and aluminum.

  The positive electrode active material layer 8 is formed by being laminated on the current collector 3 formed on the laminated film 5. The positive electrode active material layer 8 only needs to be capable of doping and dedoping lithium ions at a higher potential than the negative electrode active material layer 9. The positive electrode active material layer 8 is formed of a positive electrode mixture containing a positive electrode active material and a binder. As the positive electrode mixture, a conductive agent may be contained.

  As the positive electrode active material, a salt containing lithium and at least one transition metal selected from V, Mn, Fe, Co, Ni, Cr and Ti, for example, lithium cobaltate, lithium nickelate, nickel nickelate Examples thereof include lithium composite metal oxides partially substituted with other elements such as Mn and Co, fluorine compounds containing the above transition metals and lithium, phosphates containing the above transition metals and lithium, and the like. Specific examples of the phosphate include lithium iron phosphate. Further, as the positive electrode active material, a lithium composite metal oxide having a spinel structure such as lithium manganese spinel can be used.

  A thermoplastic resin can be used as the binder. Specific examples of the binder include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride copolymer, and hexafluoropropylene / vinylidene fluoride copolymer. Examples include polymers, fluororesins such as tetrafluoroethylene / perfluorovinyl ether copolymer, polyolefin resins such as polyethylene and polypropylene, and the like. Moreover, you may mix and use these 2 or more types. Moreover, you may use a fluororesin and polyolefin resin as a binder. For example, by containing 100 parts by weight of the positive electrode active material so that the fluororesin is 1 to 10 parts by weight and the ratio of the polyolefin resin is 0.1 parts by weight to 2 parts by weight, the connection with the current collector 3 is achieved. A positive electrode mixture having excellent adhesion can be obtained. The positive electrode mixture may contain an aggregation inhibitor such as vinylpyrrolidone.

  A carbon material can be used as the conductive agent. Examples of the carbon material include graphite powder, carbon black, acetylene black, and fibrous carbon materials (carbon nanotubes, carbon nanofibers, etc.). Since carbon black and acetylene black are fine particles and have a large surface area, by adding a small amount to the positive electrode mixture, the conductivity inside the electrode can be increased, and charge / discharge efficiency and rate characteristics can be improved. Usually, the ratio of the conductive agent in the positive electrode mixture is 5 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the positive electrode active material. When the fibrous carbon material as described above is used as the conductive agent, this ratio can be lowered.

  The positive electrode active material layer 8 is formed by supporting the positive electrode mixture on the current collector 3. Specifically, a method in which the positive electrode mixture is pressure-molded on the current collector 3, a positive electrode mixture pasted using an organic solvent or the like is applied on the current collector, and then pressed after drying. The method of adhering is mentioned. When the positive electrode mixture is made into a paste, a slurry made of, for example, a positive electrode active material, a conductive agent, a binder, and an organic solvent is prepared. Examples of the organic solvent include amine solvents such as N, N-dimethylaminopropylamine and diethylenetriamine, ether solvents such as tetrahydrofuran, ketone solvents such as methyl ethyl ketone, ester solvents such as methyl acetate, dimethylacetamide, N-methyl- Examples include amide solvents such as 2-pyrrolidone. Examples of the method for applying the positive electrode mixture to the positive electrode current collector include a slit die coating method, a screen coating method, a curtain coating method, a knife coating method, a gravure coating method, and an electrostatic spray method.

  The negative electrode active material layer 9 is formed by being laminated on the current collector 3 formed on the laminated film 5. The negative electrode active material layer 9 is formed of a negative electrode mixture containing a negative electrode active material such as graphite. The negative electrode mixture may contain a binder and a conductive agent. Examples of the binder used in the negative electrode mixture include a polymer of a fluorine compound, an addition polymer of a monomer that does not contain a fluorine atom and contains an ethylenic double bond, a polysaccharide, and a derivative thereof.

  The electrolyte layer 10 is made of a material containing an electrolytic component (here, lithium ions). The electrolyte layer 10 may be an electrolytic solution or a solid electrolyte. When an electrolytic solution is used as the electrolyte layer 10, a separator is disposed between the positive electrode active material layer 8 and the negative electrode active material layer 9 so that the positive electrode active material layer 8 and the negative electrode active material layer 9 are not in direct contact with each other. Often.

The electrolytic solution is composed of an organic solvent containing an electrolyte. The electrolytes include LiClO ₄ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiN (SO ₂ CF ₃ ) (COCF ₃ ), Li (C ₄ F ₉ SO ₃ ), LiC (SO ₂ CF ₃ ) ₃ , Li ₂ B ₁₀ Cl ₁₀ , LiBOB (where BOB represents bis (oxalato) borate), lower Examples thereof include lithium salts such as aliphatic carboxylic acid lithium salts and LiAlCl _4, and a mixture of two or more of these may be used.
In the present embodiment, the electrolyte is selected from the group consisting of LiPF ₆ containing fluorine, LiAsF ₆ , LiSbF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) ₂ and LiC (SO ₂ CF ₃ ) _3. Those containing at least one of the above are used.

  As an organic solvent of the electrolytic solution, propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, 4-trifluoromethyl-1,3-dioxolan-2-one, 1,2-di (methoxycarbonyloxy) Carbonates such as ethane; ethers such as 1,2-dimethoxyethane, 1,3-dimethoxypropane, pentafluoropropyl methyl ether, 2,2,3,3-tetrafluoropropyl difluoromethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran Esters such as methyl formate, methyl acetate and γ-butyrolactone; nitriles such as acetonitrile and butyronitrile; amides such as N, N-dimethylformamide and N, N-dimethylacetamide Carbamates such as 3-methyl-2-oxazolidone; sulfur-containing compounds such as sulfolane, dimethyl sulfoxide and 1,3-propane sultone, or those obtained by further introducing a fluorine substituent into the above organic solvent, or the above organic solvent A mixture in which two or more of these are mixed can be used.

As the organic solvent of the electrolytic solution, a mixed solvent containing carbonates is preferable, and a mixed solvent of cyclic carbonate and acyclic carbonate or cyclic carbonate and ether is more preferable. As the mixed solvent of the cyclic carbonate and the non-cyclic carbonate, a mixed solvent containing ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate is preferable in that it has a wide operating temperature range, excellent load characteristics, and hardly decomposes. From the viewpoint of ease of safety management, it is preferable to use an electrolytic solution containing a lithium salt containing fluorine such as LiPF ₆ and an organic solvent having a fluorine substituent. A mixed solvent containing ethers having fluorine substituents such as pentafluoropropyl methyl ether and 2,2,3,3-tetrafluoropropyl difluoromethyl ether and dimethyl carbonate has excellent high-current discharge characteristics, preferable.

  As said separator, the material which has forms, such as a porous film, a nonwoven fabric, a woven fabric, which consists of materials, such as polyolefin resin, such as polyethylene and a polypropylene, a fluororesin, and a nitrogen-containing aromatic polymer, can be used, for example. . Moreover, it is good also as a separator using 2 or more types of said material, and said material may be laminated | stacked.

Examples of the solid electrolyte include organic polymer electrolytes such as polyethylene oxide polymer compounds, polymer compounds containing at least one polyorganosiloxane chain or polyoxyalkylene chain. Moreover, what is called a gel type which hold | maintained the nonaqueous electrolyte solution in the high molecular compound can also be used. The _{Li 2 S-SiS 2, Li} 2 S-GeS 2, Li 2 S-P 2 S 5, Li 2 S-B 2 S 3, Li 2 S-SiS 2 -Li 3 PO 4, Li 2 S-SiS _An inorganic solid electrolyte containing a sulfide such as _2- Li ₂ SO ₄ may be used.

  The laminated films 5 and 6 are obtained by forming a barrier film on one side of a base material. This barrier film has gas barrier properties against water vapor and oxygen gas. The laminated film 5 is disposed with the barrier film 12 facing inward. The laminated film 6 is disposed with the barrier film 14 facing inward. The laminated film 6 is attached to the outside of the negative electrode active material layer 9 with an adhesive or the like. The laminated film 5 has the same structure and characteristics as the laminated film 6. That is, the base material 11 has the same structure and characteristics as the base material 13. The barrier film 12 has the same structure and characteristics as the barrier film 14.

  In addition, the base material 11 and the base material 13 may have the same thickness or may be different. The barrier film 12 and the barrier film 14 may have the same thickness or different thicknesses. Barrier films may be provided on both sides of at least one of the laminated film 5 and the laminated film 6. By providing a barrier film having gas barrier properties on both surfaces of the laminated film, the gas barrier properties can be enhanced.

  The laminated film 5 is obtained by forming a barrier film 12 on a base material 11 by a plasma chemical vapor deposition method (hereinafter referred to as a plasma CVD method). The roughness of the surface of the barrier film 12 on the first electrode 2 side is Rmax <200 nm, where Rmax is the maximum surface height. When the roughness of the surface of the barrier film 12 satisfies the above-described conditions, it is possible to suppress the occurrence of defective film formation when a film constituting a device is formed on the barrier film 12. Thereby, for example, it is possible to suppress the occurrence of disconnection or destruction of the first electrode 2. The roughness of the surface of the barrier film 12 on the first electrode 2 side preferably satisfies Rmax <150 nm, more preferably satisfies Rmax <100 nm, more preferably satisfies Rmax <50 nm, and particularly preferably satisfies Rmax <25 nm. . The smaller Rmax is, the higher the effect of suppressing the formation failure of the film constituting the device.

  The substrate 11 is a film or sheet made of a colorless and transparent resin. Examples of the resin used for the substrate 11 include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefin resins such as polyethylene (PE), polypropylene (PP), and cyclic polyolefin; polyamide resins. Polycarbonate resin; polystyrene resin; polyvinyl alcohol resin; saponified ethylene-vinyl acetate copolymer; polyacrylonitrile resin; acetal resin; polyimide resin. Among these resins, polyester resins and polyolefin resins are preferable, and PET and PEN are particularly preferable from the viewpoints of high heat resistance and linear expansion coefficient and low manufacturing cost. These resin may be used individually by 1 type, and may be used in combination of 2 or more type.

  The thickness of the base material 11 can be appropriately set in consideration of the stability when the barrier film 12 is formed. The thickness of the base material 11 may be set in the range of 5 μm or more and 500 μm or less, for example. Thereby, the base material 11 can be stably conveyed in the vacuum atmosphere when forming the barrier film 12, for example. When the barrier film 12 is formed by the plasma CVD method, the thickness of the substrate 11 is preferably set in the range of 10 μm to 200 μm, and more preferably in the range of 50 μm to 100 μm. . Thereby, the discharge for plasma generation can be stably performed through the base material 11 during the film formation by the plasma CVD method.

  By the way, in the battery cell 1, when components such as a pair of electrodes, a current collector, and an electrolyte come into contact with oxygen gas, water vapor, etc., the performance of the battery cell is reduced and the life is shortened due to deterioration of these components. Sometimes. In particular, in a battery cell using a non-aqueous electrolyte, the deterioration of the electrolytic solution due to contact with oxygen gas or water vapor is significant. The battery cell of this embodiment has sufficient gas barrier properties against oxygen gas and water vapor as will be described below.

  Each of the barrier films 12 and 14 according to this embodiment has one or more thin film layers, and at least one of the thin film layers is formed so as to satisfy a predetermined condition described later. . Since the barrier films 12 and 14 according to the present embodiment are formed so as to satisfy a predetermined condition, a decrease in gas barrier properties due to bending is suppressed. Thus, the barrier films 12 and 14 according to the present embodiment can exhibit gas barrier properties generally required for battery cells even after the barrier films 12 and 14 have been bent. is there.

  The film thickness of the thin film layer is preferably set within a range of 5 nm to 3000 nm, more preferably set within a range of 10 nm to 2000 nm, and set within a range of 100 nm to 1000 nm. It is particularly preferable. If the film thickness of the thin film layer is not less than the lower limit of the above range, it is easy to ensure the gas barrier properties generally required for battery cells. If the film thickness of the thin film layer is not more than the upper limit of the above range, the effect of suppressing the deterioration of the gas barrier property due to bending is enhanced.

  The laminated film 5 may be provided with a plurality of thin film layers. The total thickness of the plurality of thin film layers is set, for example, within a range of 10 nm to 10000 nm. The total thickness of the plurality of barrier films is preferably set within a range of 10 nm to 5000 nm, more preferably set within a range of 100 nm to 3000 nm, and within a range of 200 nm to 2000 nm. It is particularly preferable that it is set. When the total thickness of the plurality of barrier films is not less than the lower limit of the above range, it is easy to ensure gas barrier properties (oxygen permeability, water vapor permeability) generally required for battery cells. When the total thickness of the plurality of barrier films is equal to or less than the upper limit of the above range, the effect of suppressing the deterioration of the gas barrier property due to the bending of the plurality of barrier films is enhanced.

  The laminated film 5 may have one or more of a primer coat layer, a heat sealable resin layer, and an adhesive layer in addition to the base material 11 and the barrier film 12. The primer coat layer is used to improve the adhesion between the substrate 11 and the barrier film 12. The primer coat layer can be formed by appropriately using a known primer coat agent or the like. The heat-sealable resin layer can be formed by appropriately using a known heat-sealable resin or the like. The adhesive layer is used for adhering a plurality of laminated films 5 to each other, adhering the laminated films 5 to other members, and the like. The adhesive layer can be formed by appropriately using a known adhesive or the like.

  Next, the barrier film according to the present embodiment will be described in detail. In the following description, the surface of the thin film layer may be referred to as the film surface. The film thickness direction of the thin film layer may be simply referred to as the film thickness direction, and the direction parallel to the surface of the thin film layer may be referred to as the film surface direction. The film thickness direction and the film surface direction are substantially perpendicular to each other.

  The barrier film of the first aspect according to this embodiment has a thin film layer (hereinafter referred to as a first thin film layer) containing silicon, oxygen, and carbon. The first thin film layer is formed so that the atomic ratio of silicon atoms, the atomic ratio of oxygen atoms, and the atomic ratio of carbon atoms satisfy predetermined conditions. The atomic ratio of each atom is the ratio of the amount of target atoms to the total amount of silicon atoms, oxygen atoms, and carbon atoms. The unit of atomic ratio is at%. For example, the atomic ratio of silicon atoms is the ratio of the amount of silicon atoms to the total amount. The predetermined condition is a condition that satisfies all of the following first condition, second condition, and third condition.

  In the present embodiment, a curve indicating the relationship between the distance from the film surface in the film thickness direction and the local atomic ratio of silicon atoms at each distance is referred to as a silicon distribution curve. Similarly, a curve indicating the relationship between the distance from the film surface in the film thickness direction and the local atomic ratio of oxygen atoms at each distance position is referred to as an oxygen distribution curve. A curve indicating the relationship between the distance from the film surface in the film thickness direction and the local atomic ratio of carbon atoms at each distance is referred to as a carbon distribution curve. A curve showing the relationship between the distance from the film surface in the film thickness direction and the sum of the local atomic ratio of oxygen atoms and the total atomic ratio of carbon atoms at each distance is called an oxygen-carbon distribution curve.

The first condition is a condition in which the carbon distribution curve is substantially continuous. The carbon distribution curve being substantially continuous means that the carbon distribution curve does not include a portion where the carbon atomic ratio changes discontinuously. Specifically, when the distance from the film surface in the film thickness direction is x [nm] and the atomic ratio of carbon is C [at%], the following formula (1) is preferably satisfied.
| DC / dx | ≦ 1 (1)

  The second condition is a condition in which the carbon distribution curve has at least one extreme value. The extreme value here is the maximum value or the minimum value of the atomic ratio of each element with respect to the distance from the film surface in the film thickness direction. The extreme value is the value of the atomic ratio at the point where the atomic ratio of the element changes from increasing to decreasing or when the atomic ratio of the element changes from decreasing to increasing when the distance from the film surface in the film thickness direction is changed. It is. The extreme value can be obtained, for example, based on a measurement result obtained by measuring an atomic ratio at each of a plurality of measurement positions in the film thickness direction. The measurement position of the atomic ratio is set such that the interval in the film thickness direction is, for example, 20 nm or less. The position where the extreme value is taken is a position where the measurement result is changed from increase to decrease, for example, by comparing measurement results at three or more different measurement positions with respect to a discrete data group including the measurement result at each measurement position. It can be obtained by determining the position where the decrease turns to the increase. The position where the extreme value is taken can also be obtained, for example, by differentiating the approximate curve obtained from the above discrete data group. When the interval in which the atomic ratio monotonously increases or decreases monotonically from the position where the extreme value is taken is, for example, 20 nm or more, the atomic ratio at the position moved by 20 nm in the film thickness direction from the position where the extreme value is taken, and the extreme value The absolute value of the difference is, for example, 3 at% or more.

  In the first thin film layer formed so as to satisfy the second condition, the amount of increase in the gas permeability after bending with respect to the gas permeability before bending is less than that in the case where the second condition is not satisfied. That is, by satisfying the second condition, an effect of suppressing a decrease in gas barrier properties due to bending can be obtained. When the first thin film layer is formed so that the number of extreme values of the carbon distribution curve becomes two or more, the amount of increase is reduced as compared with the case where the number of extreme values of the carbon distribution curve is one. . Further, when the first thin film layer is formed so that the number of extreme values of the carbon distribution curve is three or more, the increase amount is larger than that in the case where the number of extreme values of the carbon distribution curve is two. Less. When the carbon distribution curve has two or more extreme values, the distance from the film surface in the film thickness direction at the position where the first extreme value is taken, and the second extreme value adjacent to the first extreme value The absolute value of the difference between the position and the distance from the film surface in the film thickness direction is preferably in the range of 1 nm to 200 nm, and more preferably in the range of 1 nm to 100 nm.

  The third condition is a condition in which the absolute value of the difference between the maximum value and the minimum value of the carbon atomic ratio in the carbon distribution curve is 5 at% or more. In the first thin film layer formed so as to satisfy the third condition, the amount of increase in the gas permeability after bending with respect to the gas permeability before bending is less than that in the case where the third condition is not satisfied. That is, by satisfying the third condition, an effect of suppressing a decrease in gas barrier property due to bending can be obtained. When the absolute value of the difference between the maximum value and the minimum value of the atomic ratio of carbon is 6 at% or more, the above effect is enhanced, and when it is 7 at% or more, the above effect is further enhanced.

  As the absolute value of the difference between the maximum value and the minimum value of the silicon atomic ratio in the silicon distribution curve decreases, the gas barrier property of the first thin film layer tends to improve. From such a viewpoint, the absolute value is preferably less than 5 at%, more preferably less than 4 at%, and particularly preferably less than 3 at%.

  In the oxygen-carbon distribution curve, when the total of the atomic ratio of local oxygen atoms and the atomic ratio of carbon atoms at each distance position is defined as “total atomic ratio”, the maximum and minimum values of the total atomic ratio As the absolute value of the difference between the two decreases, the gas barrier property of the first thin film layer tends to improve. From such a viewpoint, the total atomic ratio is preferably less than 5 at%, more preferably less than 4 at%, and particularly preferably less than 3 at%.

  If the first thin film layer has a substantially uniform composition in the film surface direction, the gas barrier property of the first thin film layer can be made uniform and improved. The substantially uniform composition means that in the oxygen distribution curve, the carbon distribution curve, and the oxygen carbon distribution curve, the number of extreme values is the same at any two locations on the film surface, and the carbon in each carbon distribution curve. The absolute value of the difference between the maximum value and the minimum value of the atomic ratio is the same or within 5 at%.

The silicon distribution curve, oxygen distribution curve, and carbon distribution curve of the first thin film layer preferably satisfy the following fourth condition. The fourth condition is a condition that alternatively satisfies the fifth condition or the sixth condition in a region of 90% or more of the thickness of the first thin film layer in the silicon distribution curve, oxygen distribution curve, and carbon distribution curve.
The fifth condition is a condition in which the atomic ratio of oxygen is larger than the atomic ratio of silicon and the atomic ratio of silicon is larger than the atomic ratio of carbon. The fourth condition is expressed by the following formula (2).
(Atomic ratio of oxygen)> (atomic ratio of silicon)> (atomic ratio of carbon) (2)
The sixth condition is a condition in which the atomic ratio of carbon is larger than the atomic ratio of silicon and the atomic ratio of silicon is larger than the atomic ratio of oxygen. The fifth condition is expressed by the following formula (3).
(Atomic ratio of carbon)> (Atomic ratio of silicon)> (Atomic ratio of oxygen) (3)

  The first thin film layer formed so as to satisfy the fourth condition can exhibit gas barrier properties generally required for battery cells. The gas barrier property of the first thin film layer tends to improve as the range in which the fifth condition or the sixth condition is alternatively satisfied in the film thickness of the first thin film layer increases. From such a viewpoint, it is preferable that the range in which the fifth condition or the sixth condition is alternatively satisfied in the film thickness of the first thin film layer is 95% or more of the film thickness of the first thin film layer. More preferably, it is approximately 100% of the thickness of one thin film layer.

  When the above fifth condition is satisfied, the atomic ratio of the silicon atom content to the total amount of silicon atoms, oxygen atoms and carbon atoms in the first thin film layer is preferably 25 at% or more and 45 at% or less, More preferably, it is 30 at% or more and 40 at% or less. When the above fourth condition is satisfied, the atomic ratio of the oxygen atom content to the total amount of silicon atoms, oxygen atoms and carbon atoms in the first thin film layer is preferably 33 at% or more and 67 at% or less, More preferably, it is 45 at% or more and 67 at% or less. When the above fourth condition is satisfied, the atomic ratio of the carbon atom content to the total amount of silicon atoms, oxygen atoms and carbon atoms in the first thin film layer is preferably 3 at% or more and 33 at% or less, More preferably, it is 3 at% or more and 25 at% or less.

  When the above sixth condition is satisfied, the atomic ratio of the content of silicon atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms in the first thin film layer is preferably 25 at% or more and 45 at% or less, More preferably, it is 30 at% or more and 40 at% or less. When the above fifth condition is satisfied, the atomic ratio of the oxygen atom content to the total amount of silicon atoms, oxygen atoms and carbon atoms in the first thin film layer is preferably 1 at% or more and 33 at% or less, More preferably, it is 10 at% or more and 27 at% or less. When the above fifth condition is satisfied, the atomic ratio of the carbon atom content to the total amount of silicon atoms, oxygen atoms and carbon atoms in the first thin film layer is preferably 33 at% or more and 66 at% or less, More preferably, it is 40 at% or more and 57 at% or less.

  The barrier film of the first aspect may have two or more first thin film layers. In the barrier film of the first aspect, in addition to the first thin film layer, one or more items of the type of constituent element, the ratio of the amount of atoms of each constituent element (atomic ratio), and the distribution of atomic ratio are the first. You may have a thin film layer (henceforth another thin film layer) different from a thin film layer. The other thin film layer may contain at least one of nitrogen and aluminum. The other thin film layer may contain at least one of nitrogen and aluminum in addition to silicon, oxygen, and carbon. Other thin film layers may not have gas barrier properties.

  The barrier film of the second aspect according to the present embodiment has a thin film layer (hereinafter referred to as a second thin film layer) that satisfies the following seventh condition. The seventh condition is a condition in which an electron beam transmittance curve showing the relationship between the distance from the film surface in the film thickness direction and the electron beam transmittance has at least one extreme value. The electron beam transmittance is an index representing the degree of transmission of the electron beam through the material of the second thin film layer at each position in the film thickness direction. Various known methods can be employed as a method for measuring the electron beam transmittance. For example, by measuring a secondary electron or a reflected electron using a transmission electron microscope or a scanning electron microscope. A measuring method for measuring electron beam transmittance can be employed.

  The above extreme value is the maximum value or the minimum value of the electron beam transmittance with respect to the distance from the film surface in the film thickness direction. The extreme value is the electron beam transmittance at the point where the electron beam transmittance changes from increasing to decreasing when the distance from the film surface in the film thickness direction is changed, or at the point where the electron beam transmittance changes from decreasing to increasing. Is the value of The extreme value can be obtained, for example, based on a measurement result obtained by measuring electron beam transmittance at each of a plurality of measurement positions in the film thickness direction. The measurement position of electron beam transmittance is set such that the interval in the film thickness direction is, for example, 20 nm or less. The position where the extreme value is taken is a position where the measurement result is changed from increase to decrease, for example, by comparing measurement results at three or more different measurement positions with respect to a discrete data group including the measurement result at each measurement position. It can be obtained by determining the position where the decrease turns to the increase. The position where the extreme value is taken can also be obtained, for example, by differentiating the approximate curve obtained from the above discrete data group. A specific example of a method for determining whether or not there is an extreme value will be described later.

  In the second thin film layer formed so as to satisfy the seventh condition, the amount of increase in the gas permeability after bending with respect to the gas permeability before bending is less than that in the case where the seventh condition is not satisfied. That is, by satisfying the seventh condition, an effect of suppressing a decrease in gas barrier properties due to bending can be obtained. When the second thin film layer is formed so that the number of extreme values of the electron beam transmission curve is 2 or more, the increase is as compared with the case where the number of extreme values of the electron beam transmission curve is one. The amount is reduced. In addition, when the second thin film layer is formed so that the number of extreme values of the electron beam transmission curve is 3 or more, compared to the case where the number of extreme values of the electron beam transmission curve is two, The amount of increase is less. When the electron beam transmittance curve has two or more extreme values, the distance from the film surface in the film thickness direction at the position where the first extreme value is taken and the first extreme value next to the first extreme value in the film thickness direction The absolute value of the difference from the distance from the film surface in the film thickness direction at the position where the extreme value is 2 is preferably in the range of 1 nm to 200 nm, and more preferably in the range of 1 nm to 100 nm. preferable.

The second thin film layer is preferably composed mainly of silicon oxide from the viewpoint of achieving both transparency and gas barrier properties of the second thin film layer. The main component means that the content of the component is 50% by mass or more, preferably 70% by mass or more with respect to the mass of all the components of the material. The silicon oxide is preferably about 1.0 or more and 2.0 or less, more preferably about 1.5 or more and 2.0 or less, with respect to the silicon oxide represented by the general formula SiO 2 _X. preferable. X in the above general formula may be a constant value in the film thickness direction or may vary in the film thickness direction.

The second thin film layer may contain silicon, oxygen, and carbon. In this case, it is preferable that the second thin film layer is mainly composed of a compound represented by a general formula of SiO _X C _Y. In this general formula, X is selected from positive numbers less than 2, and Y is selected from positive numbers less than 2. One or more of X, Y, and Z in the above general formula may be a constant value in the film thickness direction or may vary in the film thickness direction.

The second thin film layer may contain silicon, oxygen, carbon, and hydrogen. In this case, it is preferable that the second thin film layer is mainly composed of a compound represented by a general formula of SiO _X C _Y H _Z. In this general formula, X is selected from a positive number less than 2, Y is a positive number less than 2, and Z is a positive number less than 6. One or more of X, Y, Z, and H in the above general formula may be a constant value in the film thickness direction or may vary in the film thickness direction. The second thin film layer may contain one or more elements other than silicon, oxygen, carbon, and hydrogen, such as nitrogen, boron, aluminum, phosphorus, sulfur, fluorine, and chlorine. The second thin film layer may satisfy one or more of the first condition, the second condition, and the third condition described for the barrier film of the first aspect. That is, the second thin film layer can have the same structure as the first thin film layer.

Next, the manufacturing method and characteristics of the laminated film according to this embodiment will be described.
The laminated film of this embodiment is manufactured by forming a barrier film on a substrate. As a method for forming the barrier film of the present embodiment on the base material, for example, a plasma CVD method may be mentioned. If the barrier film is formed by the plasma CVD method, a dense barrier film can be formed, which is advantageous in improving gas barrier properties. The plasma chemical vapor deposition method may be a Penning discharge plasma type plasma chemical vapor deposition method. In addition, before forming the barrier film, a surface activation treatment for cleaning the surface of the base material may be performed so that the adhesion between the formed barrier film and the base material is improved. Examples of such surface activation treatment include corona treatment, plasma treatment, and flame treatment.

FIG. 2 is a diagram illustrating an example of a laminated film manufacturing apparatus.
2 includes a feed roll 51, a take-up roll 52, transport rolls 53 to 56, film forming rolls 57 and 58, a gas supply pipe 59, a plasma generation power source 60, electrodes 61 and 62, and a magnetic field generation. Devices 63 and 64 are provided. Among the constituent elements of the manufacturing apparatus 50, at least the film forming rolls 57 and 58, the gas supply pipe 59, and the magnetic field generators 63 and 64 are arranged in a vacuum chamber (not shown) when manufacturing a laminated film. This vacuum chamber is connected to a vacuum pump (not shown). The pressure inside the vacuum chamber is adjusted by the operation of the vacuum pump.

  The film F is wound around the feed roll 51. In this example, the film F is a base material of the base material 11. The manufacturing apparatus 50 can form a thin film layer on the film F by a plasma CVD method. Note that a barrier film including two or more thin film layers can be formed using the manufacturing apparatus 50. For example, when a film in which one thin film layer is formed on a base material is used as the film F, a second thin film layer can be stacked on the base material. Similarly, a barrier film including a plurality of thin film layers can be formed by repeating the lamination of the thin film layers as many times as necessary.

  The film F is conveyed from the delivery roll 51 to the film forming roll 57 via the conveyance roll 53. The film F is transported from the film forming roll 57 to the film forming roll 58 via the transport roll 54 and the transport roll 55. The film F is transported from the film forming roll 58 to the take-up roll 52 via the transport roll 56 and is taken up by the take-up roll 52.

  The film forming roll 57 and the film forming roll 58 are disposed so as to face each other. The axis of the film forming roll 57 in this example is substantially parallel to the axis of the film forming roll 58. The diameter of the film forming roll 57 in this example is substantially the same as the diameter of the film forming roll 58. In this example, a thin film layer is formed on the film F when the film F is conveyed on the film forming roll 57 and when the film F is conveyed on the film forming roll 58.

  The manufacturing apparatus 50 can generate plasma in a space SP sandwiched between the film forming roll 57 and the film forming roll 58. The plasma generating power source 60 is electrically connected to the electrode 61 and the electrode 62. The electrode 61 and the electrode 62 are arranged so as to sandwich the space SP. The electrode 61 and the electrode 62 are electrically connected to a plasma generation power source 60. In this example, the electrode 61 is a part of the film forming roll 57, and the electrode 62 is a part of the film forming roll 58.

  The manufacturing apparatus 50 can generate plasma by the electric power supplied to the electrode 61 and the electrode 62 from the plasma generation power source 60. As the plasma generating power source 60, a known power source or the like can be appropriately used. The power source 60 for generating plasma in this example is an AC power source that can alternately reverse the polarities of the electrodes 61 and 62. From the viewpoint of enabling efficient film formation, the plasma generating power source 60 has an applied power of, for example, 100 W or more and 10 kW or less, and an AC frequency of, for example, 50 Hz or more and 500 kHz or less.

  The magnetic field generator 63 and the magnetic field generator 64 can generate a magnetic field in the space SP. The magnetic field generator 63 and the magnetic field generator 64 may generate a magnetic field such that the magnetic flux density changes in the transport direction on the film forming roll 57 and in the transport direction on the film forming roll 58. The magnetic field generator 63 of this example is disposed inside the film forming roll 57. The magnetic field generator 64 of this example is disposed inside the film forming roll 58. The magnetic field generators 63 and 64 of this example are attached so that the posture does not change with the rotation of the film forming rolls 57 and 58.

  The gas supply pipe 59 can supply the supply gas G used for forming the thin film layer to the space SP. The supply gas G contains a raw material gas for the thin film layer. The source gas supplied from the gas supply pipe 59 is decomposed by plasma generated in the space SP. A film component of the thin film layer is generated through decomposition of the source gas. The film component of the thin film layer is deposited on the film F transported on the film forming roll 57 and on the film F transported on the film forming roll 58.

As the source gas, for example, an organosilicon compound containing silicon can be used. Examples of such organosilicon compounds include hexamethyldisiloxane, 1.1.3.3-tetramethyldisiloxane, vinyltrimethylsilane, methyltrimethylsilane, hexamethyldisilane, methylsilane, dimethylsilane, trimethylsilane, diethyl Examples thereof include silane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, and octamethylcyclotetrasiloxane. Among these organosilicon compounds, hexamethyldisiloxane and 1.1.3.3-tetramethyldisiloxane are preferable from the viewpoints of properties such as the handleability of the compound and the gas barrier property of the obtained thin film layer. Moreover, these organosilicon compounds can be used individually by 1 type or in combination of 2 or more types.
Moreover, it is good also as using as a silicon source of the barrier film | membrane which contains monosilane other than the above-mentioned organosilicon compound as source gas, and forms.

  The supply gas G may contain a reaction gas in addition to the raw material gas. As the reaction gas, a gas that reacts with the raw material gas to become an inorganic compound such as oxide or nitride can be appropriately selected and used. As a reaction gas for forming an oxide, for example, oxygen or ozone can be used. Moreover, as a reactive gas for forming nitride, nitrogen and ammonia can be used, for example. These reaction gases can be used singly or in combination of two or more. For example, when forming an oxynitride, the reaction gas for forming an oxide and a nitride are formed. Can be used in combination with the reaction gas for

  The supply gas G may include at least one of a carrier gas and a discharge gas. As the carrier gas, a gas that promotes the supply of the source gas into the vacuum chamber can be appropriately selected and used. As the discharge gas, a gas that promotes the generation of plasma discharge in the space SP can be appropriately selected and used. As the carrier gas and the discharge gas, for example, a rare gas such as helium, argon, neon, or xenon; hydrogen can be used.

In this example, a case of manufacturing a silicon-oxygen-based thin film layer will be described as an example. The supply gas G of this example contains hexamethyldisiloxane (organosilicon compound: HMDSO: (CH ₃ ) ₆ Si ₂ O :) as a raw material gas and oxygen (O ₂ ) as a reaction gas. .

When the supply gas G containing hexamethyldisiloxane and oxygen is reacted in the plasma CVD method, silicon dioxide is generated by the reaction shown in the following formula (4).
_{(CH 3) 6 Si 2 O} + 12O 2 → 6CO 2 + 9H 2 O + 2SiO 2 ··· (4)

  The ratio of the amount of the reaction gas to the amount of the source gas in the supply gas G is, for example, the ratio of the amount of the reaction gas stoichiometrically required to completely react the source gas and the reaction gas (stoichiometry). Ratio) is set so as not to be excessively high. For example, in the reaction represented by the formula (4), the stoichiometric amount of oxygen required to completely oxidize 1 mol of hexamethyldisiloxane is 12 mol. That is, when the supply gas G contains 12 moles or more of oxygen with respect to 1 mole of hexamethyldisiloxane, theoretically, a uniform silicon dioxide film is formed as a thin film layer. In practice, a part of the supplied reaction gas may not contribute to the reaction. Therefore, in order to completely react the raw material gas, a gas containing the reaction gas is usually supplied at a ratio higher than the stoichiometric ratio. The molar ratio (hereinafter referred to as the effective ratio) of the reaction gas that can actually react the raw material gas to the raw material gas can be examined by experiments or the like. For example, in order to completely oxidize hexamethyldisiloxane by the plasma CVD method, the molar amount (flow rate) of oxygen is 20 times (effective ratio is 20) or more of the molar amount (flow rate) of hexamethyldisiloxane as a raw material. There is also. From such a viewpoint, the ratio of the amount of the reaction gas to the amount of the raw material gas in the supply gas G may be less than the effective ratio (for example, 20), may be less than the stoichiometric ratio (for example, 12), or may be stoichiometric. A value lower than the ratio (for example, 10) may be used. Further, from the viewpoint of ensuring the transparency of the thin film layer, the ratio of the amount of the reaction gas to the amount of the raw material gas is preferably 0.1 or more, and more preferably 0.5 or more.

  As described above, when the reaction gas is insufficiently reacted for completely reacting the raw material gas, carbon atoms and hydrogen atoms in hexamethyldisiloxane that have not been completely oxidized are taken into the thin film layer. Accordingly, in the thin film layer, the distribution of the atomic ratio with respect to the distance from the film surface in the film thickness direction or the distribution of the electron beam transmittance with respect to the distance from the film surface in the film thickness direction satisfies the predetermined condition. Can be formed. For example, in the manufacturing apparatus 50, the type of source gas, the ratio of the molar amount of the reaction gas to the molar amount of the source gas in the supply gas G, the power supplied to the electrodes 61 and 62, the pressure in the vacuum chamber, the film forming roll 57 The thin film layer can be formed so as to satisfy a predetermined condition by appropriately adjusting one or more parameters such as the diameter of 58 and the conveyance speed of the film F. Note that one or more of the above parameters may be changed temporally within a period in which the film F passes through the film formation area facing the space SP, or may be changed spatially within the film formation area. .

  The power supplied to the electrodes 61 and 62 can be appropriately adjusted according to the type of source gas, the pressure in the vacuum chamber, and the like. The power supplied to the electrodes 61 and 62 is set within a range of 0.1 kW to 10 kW, for example. If the power supplied to the electrodes 61 and 62 is 0.1 kW or more, the generation of particles is suppressed. If the electric power supplied to the electrodes 61 and 62 is 10 kW or less, the film F is prevented from being wrinkled or damaged by the heat received by the film F from the electrodes 61 and 62. Further, the occurrence of abnormal discharge between the film forming rolls 57 and 58 due to the damage of the film F is avoided, and the film forming rolls 57 and 58 are also prevented from being damaged by the abnormal discharge. The pressure in the vacuum chamber (degree of vacuum) can be appropriately adjusted according to the type of source gas. The pressure in the vacuum chamber is set, for example, within a range of 0.1 Pa to 50 Pa. The conveyance speed (line speed) of the film F can be adjusted as appropriate according to the type of source gas, the pressure in the vacuum chamber, and the like. The conveyance speed of the film F may be set, for example in the range of 0.1 m / min or more and 100 m / min or less, and may be set in the range of 0.5 m / min or more and 20 m / min or less. If a conveyance speed is more than the lower limit of said range, it will be suppressed that a wrinkle generate | occur | produces in the film F with a heat | fever etc. If the conveyance speed is less than or equal to the upper limit of the above range, it is easy to increase the thickness of the formed thin film layer.

Next, although the laminated film which concerns on this embodiment is demonstrated concretely based on an Example and a comparative example, the application range of this invention is not limited to a following example.
Example 1
FIG. 3A is an image showing a cross section of the barrier film in Example 1, and FIG. 3B is a graph showing electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film in Example 1. FIG. 4 is a graph showing the distribution of atomic ratios in the barrier film of Example 1. The film thickness direction of the barrier film is substantially the same as the film thickness direction of the thin film layer.

In Example 1, a laminated film was produced using the production apparatus 50 shown in FIG. As the film F, a biaxially stretched polyethylene naphthalate film (manufactured by Teijin DuPont Films, trade name “Teonex Q65FA”) was used. This film F has a thickness of 100 μm and a width of 350 mm. In manufacturing the laminated film, the film F was mounted on the delivery roll 51. A magnetic field is generated in the space SP by the magnetic field generators 63 and 64, and power is supplied from the plasma generation power source 60 to the electrodes 61 and 62 to discharge the space SP, thereby generating plasma in the space SP. It was. A supply gas G containing hexamethyldisiloxane (HMDSO) as a source gas and an oxygen gas that functions as a reaction gas and a discharge gas is supplied to the space SP together with the generation of plasma, and the following film formation conditions A thin film layer was formed on the film F by the plasma CVD method, and a laminated film having the thin film layer as a barrier film was obtained. In the film forming conditions of Example 1, the supply amount of the source gas is 50 sccm in terms of 1 atm at 0 ° C., the supply amount of oxygen gas is 500 sccm in terms of 1 atm at 0 ° C., the degree of vacuum in the vacuum chamber is 3 Pa, and plasma is generated. The applied power from the power source 60 is 0.8 kW, the frequency of the plasma generating power source is 70 kHz, and the conveyance speed of the film F is 0.5 m / min. The thickness of the thin film layer in the obtained laminated film was 0.3 μm. When the roughness of the surface of the barrier film in the obtained laminated film was measured with an atomic force microscope (AFM), the maximum surface height Rmax was 13 nm in a region having an area of 1 μm ² .

  About the laminated | multilayer film of Example 1, the electron beam transmittance | permeability curve which shows the relationship between the distance from the reference plane in a film thickness direction and electron beam transmittance was created. The reference plane is a predetermined plane parallel to the surface of the thin film layer. In this example, a reference plane was set near the interface between the substrate and the thin film layer. In this example, an electron beam transmission curve was prepared as follows.

  First, a protective layer was provided on the surface of the thin film layer of the laminated film. Then, using a focused ion beam, the laminated film was cut to prepare a sample. The normal direction of the surface of the sample is a direction orthogonal to the film thickness direction. The dimension of the sample in the normal direction of the sample surface was set to 100 nm. Then, using a transmission electron microscope (TEM, manufactured by Hitachi, Ltd., model number “FE-SEM HF-2000”), the surface of the sample was observed at a magnification of 100,000 times, and FIG. The image shown was obtained. Under observation conditions, the acceleration voltage is 200 KV and the objective aperture is 160 μm. As shown in FIG. 2A, a striped pattern was observed in the TEM image. In this image, the film thickness direction is a direction (lateral direction of the image) perpendicular to the extending direction of the striped pattern.

  Next, the above TEM image was analyzed with a personal computer using image processing software (trade name “Adobe PhotoShop Elements 7” manufactured by Adobe System Co., Ltd.). Specifically, a gray image was obtained by cutting out a part of the image. Then, the cut-out gray image was divided into a lattice shape and divided into 700 unit regions in the film thickness direction and 500 unit regions in the film surface direction. In the grayscale image, 200 nm was a length corresponding to 202 unit regions. Then, for each unit region of the obtained gray image, a cross-sectional gray variable indicating the degree of light and shade was obtained. Specifically, the TEM image was an 8-bit gray image, and the cross-sectional density variable was obtained using the gradation value of the pixel included in the unit area for each unit area. The gradation value in the 8-bit gray image has 256 levels from 0 corresponding to black to 255 corresponding to white. The operation for dividing the region to be measured into unit regions and the operation for obtaining the cross-sectional density variable were performed using an image analysis software (Rigaku Corporation, product name “Rigaku R-AXIS Display Software Ver. 1.18”). .

  Next, the average value of the cross-sectional density variables of the unit region where the distance from the reference plane in the film thickness direction has a predetermined value was calculated, and the calculated average value was used as the thickness direction density variable. The average value of the cross-sectional density variable is preferably the average value of the cross-sectional density variables of any 100 or more unit regions whose distance from the reference plane has a predetermined value. In this example, the average value of the cross-sectional density variables of 500 unit regions arranged in the film surface direction at each position in the film thickness direction was calculated to obtain the thickness direction density variable.

  Next, the noise removal work of the thickness direction density variable was performed. For the noise removal operation, a moving average method, an interpolation method, or the like can be used. Examples of the moving average method include a simple moving average method, a weighted moving average method, and an exponential smoothing moving average method. In this embodiment, noise is removed using a simple moving average method. When removing noise using the simple moving average method, the average range is sufficiently smaller than the typical dimensions of the thin film layer structure in the film thickness direction, for example, the film thickness of the thin film layer. Is preferably selected appropriately so that is sufficiently smooth. Examples of the data interpolation method include a spline interpolation method, a Lagrangian interpolation method, and a linear interpolation method, and it is more preferable to employ the spline interpolation method and the Lagrange interpolation method.

  In the vicinity of both interfaces of the thin film layer, there may occur a region (hereinafter referred to as a transition region) in which the change in the thickness direction gradation variable is moderate with respect to the change in the distance from the film surface in the thickness direction. Possible causes of the transition region include the non-planarity of the thin film interface and the rounding of data in the above noise removal operation. It is desirable to remove the transition region from the determination region used for determining the presence / absence of the extreme value from the viewpoint of clarifying the criterion for determining the presence / absence of the extreme value of the electron beam transmission curve.

In this example, the transition region was removed from the determination region used for determining the presence or absence of the extreme value in the electron beam transmittance curve by the following method. First, in the film thickness direction, a position where the absolute value of the slope of the electron beam transmittance curve is maximized near both interfaces of the thin film layer is set as a temporary interface position. Next, the absolute value of the slope of the electron beam transmittance curve is sequentially confirmed from the outside of the temporary interface position toward the inside (thin film layer side). A distance from the reference plane in the film thickness direction, which is the absolute value as a threshold value, is obtained, and a position corresponding to this distance is set as the position of the interface of the thin film layer. The above threshold is, for example, 0.1 nm ⁻¹ when the gradation value of the image to be analyzed is 256 levels. Then, the region outside the interface of the thin film layer is removed from the determination region as a transition region.

  Next, the thickness direction density variable was normalized so that the average value of the thickness direction density variable in the range corresponding to the thin film layer was 1. And in the laminated film, the graph which shows the relationship of the thickness direction light / dark variable with respect to the distance from the reference plane in a film thickness direction was created. Since the thickness direction density variable is proportional to the electron beam transmittance, the normalized thickness direction density variable can be treated as the normalized electron beam transmittance.

  In this example, the presence or absence of an extreme value was determined as follows. The fact that the electron beam transmission curve does not have an extreme value corresponds to the electron beam transmission curve being monotonously increasing or monotonically decreasing. When the electron beam transmission curve is monotonically increasing, the minimum value of the slope of the electron beam transmission curve in the film thickness direction is a positive value. When the electron beam transmission curve is monotonously decreasing, the maximum value of the slope of the electron beam transmission curve in the film thickness direction is a negative value. That is, theoretically, if the slope of the electron beam transmission curve in the film thickness direction includes a positive value and a negative value, the electron beam transmission curve has an extreme value. Actually, even an electron beam transmission curve having no extreme value may be determined to have an extreme value due to noise such as an electron beam transmittance measurement error.

  In the present embodiment, fluctuations due to noise and extreme values are distinguished based on the following criteria. First, a temporary extreme point is defined as a point where the sign of the thickness direction gradient variable has its slope reversed across zero. Then, when the absolute value of the difference between the film thickness direction grayscale variable at the temporary extreme value point and the film thickness direction grayscale variable at another temporary extreme value point adjacent to this temporary extreme value point is equal to or larger than the threshold value, The extreme point is determined to be a point having an extreme value. When there are two adjacent temporary extreme points, the one with the larger absolute value of the difference is selected. When the gradation value of the image to be analyzed is 256 levels, and the electron beam transmission curve is based on the thickness direction density variable normalized with the average value of the thickness direction density variable set to 1, the above-mentioned The threshold is 0.03, for example.

In the graph of FIG. 3B, the horizontal axis indicates the distance from the reference plane in the film thickness direction, and the vertical axis indicates the normalized electron beam transmittance. As shown in FIG. 3B, the electron beam transmittance curve in Example 1 has a plurality of distinct extreme values. The range in which the presence or absence of the extreme value of the electron beam transmittance curve is determined is a range in which the distance from the reference plane in the film thickness direction is 210 nm or more and 520 nm or less. In the range in which the presence / absence of the extreme value of the electron beam transmittance curve is determined, the slope obtained by differentiating the electron beam transmittance curve with the distance from the reference plane in the film thickness direction was calculated. When the maximum value and the minimum value of the inclination were obtained, the maximum value of the inclination was 3.79 × 10 ⁻³ nm ⁻¹ and the minimum value of the inclination was −4.75 × 10 ⁻³ nm ⁻¹ . The absolute value of the difference between the maximum value and the minimum value of the slope was 8.54 × 10 ⁻³ nm ⁻¹ . In the electron beam transmission curve, there were some sites where the absolute value of the difference between the adjacent maximum and minimum electron beam transmittances was 0.03 or more. Thus, in Example 1, the extreme value distinguished from noise was detected according to the determination method of the presence or absence of the extreme value mentioned above. That is, it was confirmed that the thin film layer in the laminated film of Example 1 satisfies the seventh condition as a predetermined condition.

  In addition, a silicon distribution curve, an oxygen distribution curve, a carbon distribution curve, and an oxygen carbon distribution curve were obtained. The atomic ratio at each distance from the film surface can be obtained by, for example, XPS depth profile measurement. In XPS depth profile measurement, the inside of the sample is sequentially exposed at each distance (depth) from the sample surface before etching by etching the sample by ion sputtering or the like. Then, surface composition analysis at each depth inside the exposed sample is performed by X-ray photoelectron spectroscopy (XPS) or the like. Thereby, the atomic ratio at each distance from the film surface in the film thickness direction is obtained.

In Example 1, XPS depth profile measurement was performed under the following measurement conditions. The X-ray photoelectron spectrometer used for XPS depth profile measurement is a model name “VG Theta Probe” manufactured by Thermo Fisher Scientific. In the measurement, the irradiated X-ray of the X-ray photoelectron spectrometer was set to single crystal spectroscopy AlKα, and the X-ray spot and its size were set to an elliptical shape of 800 × 400 μm. Under the measurement conditions, the etching ion species was set to argon (Ar ⁺ ), the etching rate was set to 0.05 nm / sec in terms of SiO ₂ thermal oxide film, and the etching interval was set to 10 nm in terms of SiO ₂ .

  In the graph shown in FIG. 4, the vertical axis represents the atomic ratio, and the horizontal axis represents a value indicating the distance from the film surface in the film thickness direction. In the XPS depth profile measurement, the distance from the film surface in the film thickness direction can be calculated using the etching rate and the etching time, and is proportional to the etching time when the etching rate is substantially constant. In the graph of FIG. 4, the first horizontal axis represents the etching time, and the second horizontal axis represents the calculated value of the distance from the film surface in the film thickness direction.

  As shown in FIG. 4, in the thin film layer in Example 1, the carbon distribution curve is substantially continuous (first condition), and the carbon distribution curve has a plurality of distinct extreme values (second condition). In the carbon distribution curve, it was confirmed that the absolute value of the difference between the maximum value and the minimum value of the atomic ratio of carbon was 5 at% or more (third condition). Thus, it was confirmed that the thin film layer in the laminated film of Example 1 satisfies all of the first condition to the third condition as predetermined conditions.

  Moreover, with respect to the laminated film of Example 1, the water vapor permeability before bending and the water vapor permeability after bending were measured, and the gas barrier properties of the laminated film were evaluated.

The water vapor permeability before bending was measured under two types of measurement conditions. Under the first measurement conditions, the measurement was performed using a water vapor transmission rate measuring device (manufactured by GTR Tech, model name “GTR Tech-30XASC”). Under the first measurement conditions, the temperature of the measurement environment is 40 ° C., the humidity on one side (low humidity side) of the laminated film is 0% RH, and the humidity on the other side (high humidity side) of the laminated film is 90% RH. Set. Under the first measurement condition, the water vapor transmission rate was 3.1 × 10 ⁻⁴ g / (m ² · day). Under the second measurement condition, measurement was performed using a water vapor transmission rate measuring device (manufactured by Lyssy, model name “Lyssy-L80-5000”). Under the second measurement conditions, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. Under the second measurement conditions, the water vapor permeability was a value below the detection limit.
As described above, it was confirmed that the laminated film can exhibit a gas barrier property sufficient to suppress the penetration of water vapor into the pair of electrodes and the electrolyte layer in the battery cell.

  The water vapor permeability after bending was measured using a water vapor permeability measuring machine (manufactured by Lyssy, model name “Lyssy-L80-5000”). In the measurement, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. Prior to measuring the water vapor transmission rate, the laminated film was wound around a metal rod and allowed to stand for 1 minute, and then the laminated film was returned to a flat state to prepare a sample. Note that the radius of curvature of the laminated film when the laminated film is wound around the metal rod for only one turn is substantially the same as ½ of the diameter of the metal rod. The radius of curvature of the laminated film when the laminated film is wound around the metal rod a plurality of times, the more the laminated film is the outer laminated film in the radial direction of the metal rod, It becomes larger than 1/2 of the diameter of the bar. Here, the radius of curvature of the laminated film when the laminated film is wound a plurality of times on a metal rod is 1/2 of the diameter of the outer periphery of the wound film. The water vapor permeability of the laminated film in a state of being bent at a radius of curvature of 8 mm and returning to a flat surface was a value below the detection limit. Thus, it was confirmed that the laminated film of Example 1 was sufficiently suppressed from being deteriorated in gas barrier properties due to bending.

(Example 2)
FIG. 5A is an image showing a cross section of the barrier film in Example 2, and FIG. 5B is a graph showing electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film in Example 2. FIG. 6 is a graph showing the distribution of atomic ratios in the barrier film of Example 2.

In Example 2, a barrier film was formed by laminating three thin film layers similar to those in Example 1. Specifically, a thin film layer having a thickness of 0.3 μm was formed on the film F in the same manner as in Example 1. And the film F in which the 1st thin film layer was formed was mounted | worn to the sending-out roll 51, and the 2nd thin film layer was formed in thickness of 0.3 micrometer on the 1st thin film layer. And the film F in which the 2nd thin film layer was formed was mounted | worn to the sending-out roll 51, and the 3rd thin film layer was formed in thickness of 0.3 micrometer on the 2nd thin film layer. In the obtained laminated film, the total thickness of the plurality of thin film layers was 0.9 μm. When the roughness of the surface of the barrier film in the obtained laminated film was measured with an atomic force microscope, the maximum surface height Rmax was 13 nm in an area having an area of 1 μm ² .

For the laminated film of Example 2, in the same manner as in Example 1, an electron beam transmittance curve showing the relationship between the distance from the reference plane in the film thickness direction and the electron beam transmittance was created. As shown in FIG. 5B, the electron beam transmittance curve in Example 2 has a plurality of distinct extreme values. The range in which the presence or absence of the extreme value of the electron beam transmittance curve is determined is a range in which the distance from the reference plane in the film thickness direction is 50 nm or more and 920 nm or less. In the range in which the presence / absence of the extreme value of the electron beam transmittance curve is determined, the slope obtained by differentiating the electron beam transmittance curve with the distance from the reference plane in the film thickness direction was calculated. When the maximum value and the minimum value of the inclination were obtained, the maximum value of the inclination was 1.59 × 10 ⁻³ nm ⁻¹ and the minimum value of the inclination was −1.82 × 10 ⁻³ nm ⁻¹ . The absolute value of the difference between the maximum value and the minimum value of the slope was 3.41 × 10 ⁻³ nm ⁻¹ . In the electron beam transmission curve, there were some sites where the absolute value of the difference between the adjacent maximum and minimum electron beam transmittances was 0.03 or more. Thus, in Example 2, the extreme value distinguished from noise was detected according to the determination method of the presence / absence of the extreme value described above. That is, it was confirmed that the thin film layer in the laminated film of Example 2 satisfies the seventh condition as a predetermined condition.

  Moreover, the silicon distribution curve, the oxygen distribution curve, the carbon distribution curve, and the oxygen carbon distribution curve were obtained for the laminated film of Example 2 in the same manner as in Example 1. As shown in FIG. 6, in any of the three thin film layers, the silicon atomic ratio, the oxygen atomic ratio, and the carbon atomic ratio satisfy the first condition, and the carbon distribution curve has a plurality of distinct poles. Satisfy the second condition, and satisfy the third condition in which the absolute value of the difference between the maximum value and the minimum value of the carbon atomic ratio in the carbon distribution curve is 5 at% or more. Was confirmed. Thus, it was confirmed that the thin film layer in the laminated film of Example 2 satisfied all of the first condition to the third condition as predetermined conditions.

Further, the gas barrier properties of the laminated film of Example 2 were evaluated in the same manner as in Example 1. The water vapor permeability before bending was measured under two types of measurement conditions. Under the first measurement conditions, the measurement was performed using a water vapor transmission rate measuring device (manufactured by GTR Tech, model name “GTR Tech-30XASC”). Under the first measurement conditions, the temperature of the measurement environment is 40 ° C., the humidity on one side (low humidity side) of the laminated film is 0% RH, and the humidity on the other side (high humidity side) of the laminated film is 90% RH. Set. Under the first measurement condition, the water vapor transmission rate was 6.9 × 10 ⁻⁴ g / (m ² · day). Under the second measurement condition, measurement was performed using a water vapor transmission rate measuring device (manufactured by Lyssy, model name “Lyssy-L80-5000”). Under the second measurement conditions, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. Under the second measurement conditions, the water vapor permeability was a value below the detection limit.
As described above, it was confirmed that the laminated film can exhibit a gas barrier property sufficient to suppress the penetration of water vapor into the pair of electrodes and the electrolyte layer side of the battery cell.

  The water vapor permeability after bending was measured using a water vapor permeability measuring machine (manufactured by Lyssy, model name “Lyssy-L80-5000”). In the measurement, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. The water vapor permeability of the laminated film in a state of being bent at a radius of curvature of 8 mm and returning to a flat surface was a value below the detection limit. From this, it was confirmed that the laminated film of Example 2 sufficiently suppresses the decrease in gas barrier properties due to bending.

(Example 3)
FIG. 7 is a graph showing the distribution of atomic ratios in the barrier film of Example 3.
In Example 3, a thin film layer was formed in the same manner as in Example 1 except that the supply amount of the source gas was changed to 100 sccm in terms of 1 atm at 0 ° C., and a laminated film having this thin film layer as a barrier film was produced. The thickness of the thin film layer in the obtained laminated film was 0.6 μm. When the roughness of the surface of the barrier film in the obtained laminated film was measured with an atomic force microscope, the maximum surface height Rmax was 12 nm in an area having an area of 1 μm ² .

  Moreover, the silicon distribution curve, the oxygen distribution curve, the carbon distribution curve, and the oxygen carbon distribution curve were obtained for the laminated film of Example 3 in the same manner as in Example 1. As shown in FIG. 7, in the thin film layer, the carbon distribution curve is substantially continuous (first condition), the carbon distribution curve has a plurality of distinct extreme values (second condition), and the carbon distribution curve. It was confirmed that the absolute value of the difference between the maximum value and the minimum value of the carbon atomic ratio was 5 at% or more (third condition). Thus, it was confirmed that the thin film layer in the laminated film of Example 3 satisfied all of the first condition to the third condition as predetermined conditions.

Further, the gas barrier properties of the laminated film of Example 3 were evaluated in the same manner as in Example 1. The water vapor permeability before bending was measured under two types of measurement conditions. Under the first measurement conditions, the measurement was performed using a water vapor transmission rate measuring device (manufactured by GTR Tech, model name “GTR Tech-30XASC”). Under the first measurement conditions, the temperature of the measurement environment is 40 ° C., the humidity on one side (low humidity side) of the laminated film is 0% RH, and the humidity on the other side (high humidity side) of the laminated film is 90% RH. Set. Under the first measurement conditions, the water vapor transmission rate was 3.2 × 10 ⁻⁴ g / (m ² · day). Under the second measurement condition, measurement was performed using a water vapor transmission rate measuring device (manufactured by Lyssy, model name “Lyssy-L80-5000”). Under the second measurement conditions, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. Under the second measurement conditions, the water vapor permeability was a value below the detection limit.
As described above, it was confirmed that the laminated film can exhibit a gas barrier property sufficient to suppress the penetration of water vapor into the pair of electrodes and the electrolyte layer side of the battery cell.

  The water vapor permeability after bending was measured using a water vapor permeability measuring machine (manufactured by Lyssy, model name “Lyssy-L80-5000”). In the measurement, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. The water vapor permeability of the laminated film in a state of being bent at a radius of curvature of 8 mm and returning to a flat surface was a value below the detection limit. From this, it was confirmed that the laminated film of Example 3 sufficiently suppresses a decrease in gas barrier properties due to bending.

(Comparative Example 1)
FIG. 8A is an image showing a cross section of the barrier film in Comparative Example 1, and FIG. 8B is a graph showing electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film in Comparative Example 1. FIG. 9 is a graph showing the distribution of atomic ratios in the barrier film of Comparative Example 1.

  In Comparative Example 1, a thin film layer made of silicon oxide was formed on a substrate, and a comparative laminated film using this thin film layer as a barrier film was obtained. As the above-mentioned film, the same axially stretched polyethylene naphthalate film (manufactured by Teijin DuPont Films, trade name “Teonex Q65FA”) as in Examples 1 to 3 was used. This film F has a thickness of 100 μm and a width of 350 mm. In Comparative Example 1, a thin film layer was formed on the above film by a reactive sputtering method using a silicon target in an oxygen-containing gas atmosphere.

About the laminated | multilayer film of the comparative example 1, it carried out similarly to Example 1, and created the electron beam transmittance curve which shows the relationship between the distance from the reference plane in a film thickness direction, and electron beam transmittance. In Comparative Example 1, the surface of the protective film formed on the sample was used as a reference plane in the film thickness direction. As shown in FIG. 8B, the electron beam transmittance curve in Comparative Example 1 does not have a clear extreme value. The range in which the presence or absence of the extreme value of the electron beam transmittance curve is determined is a range in which the distance from the reference plane in the film thickness direction is 640 nm or more and 690 nm or less. In the range in which the presence / absence of the extreme value of the electron beam transmittance curve is determined, the slope obtained by differentiating the electron beam transmittance curve with the distance from the reference plane in the film thickness direction was calculated. When the maximum value and the minimum value of the inclination were obtained, the maximum value of the inclination was 0.477 × 10 ⁻³ nm ⁻¹ and the minimum value of the inclination was 0.158 × 10 ⁻³ nm ⁻¹ . Thus, since the maximum value and the minimum value of the slope are both positive values, it can be seen that there is no extreme value. The absolute value of the difference between the maximum value and the minimum value of the slope was 0.319 × 10 ⁻³ nm ⁻¹ . In Comparative Example 1, no extreme value distinguished from noise was detected in accordance with the above-described determination method for the presence or absence of an extreme value. Thus, it was confirmed that the thin film layer in the laminated film of Comparative Example 1 does not satisfy the seventh condition.

  For the laminated film of Comparative Example 1, a silicon distribution curve, an oxygen distribution curve, a carbon distribution curve, and an oxygen carbon distribution curve were prepared by the same method as in Example 1. As shown in FIG. 9, in the comparative example 1, it was confirmed that the carbon distribution curve has no extreme value. Thus, it was confirmed that the thin film layer in the laminated film of Comparative Example 1 did not satisfy the predetermined conditions regarding the first condition to the third condition.

In addition, the gas barrier properties of the laminated film of Comparative Example 1 were evaluated in the same manner as in Example 1. The water vapor permeability was measured by using a water vapor permeability measuring machine (manufactured by GTR Tech, model name “GTR Tech-30XASC”). The temperature of the measurement environment was set to 40 ° C., the humidity on one side (low humidity side) of the laminated film was set to 0% RH, and the humidity on the other side (high humidity side) of the laminated film was set to 90% RH. In the laminated film of Comparative Example 1, the water vapor permeability under the above measurement conditions was 1.3 g / (m ² · day). The laminated film of Comparative Example 1 was insufficient in gas barrier properties as compared with gas barrier properties generally required for battery cells.

(Comparative Example 2)
FIG. 10A is an image showing a cross section of the barrier film in Comparative Example 2, and FIG. 10B is a graph showing electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film in Comparative Example 2. FIG. 11 is a graph showing the distribution of atomic ratios in the barrier film of Comparative Example 2.

  In Comparative Example 2, a thin film layer was formed in the same manner as in Example 1 except that the supply amount of the source gas was 25 sccm in terms of 1 atm at 0 ° C., and a comparative laminated film having this thin film layer as a barrier film was formed. Obtained. In the obtained laminated film, the thickness of the thin film layer was 190 nm.

About the laminated | multilayer film of the comparative example 2, it carried out similarly to Example 1, and created the electron beam transmittance curve which shows the relationship between the distance from the reference plane in a film thickness direction, and electron beam transmittance. In Comparative Example 2, the surface of the protective film formed on the sample was used as a reference plane in the film thickness direction. As shown in FIG. 10B, the electron beam transmittance curve in Comparative Example 2 does not have a clear extreme value. The range in which the presence or absence of the extreme value of the electron beam transmittance curve is determined is a range in which the distance from the reference plane in the film thickness direction is 40 nm or more and 160 nm or less. In the range in which the presence / absence of the extreme value of the electron beam transmittance curve is determined, the slope obtained by differentiating the electron beam transmittance curve with the distance from the reference plane in the film thickness direction was calculated. When the maximum value and the minimum value of the inclination were obtained, the maximum value of the inclination was 0.406 × 10 ⁻³ nm ⁻¹ and the minimum value of the inclination was −0.548 × 10 ⁻³ nm ⁻¹ . The absolute value of the difference between the maximum value and the minimum value of the slope was 0.954 × 10 ⁻³ nm ⁻¹ . In Comparative Example 2, when the positive / negative fluctuation of the slope value was examined by the above-described determination method of the presence / absence of the extreme value, the absolute value of the difference between the adjacent maximum value and the minimum value in the film thickness direction variable was 0.03 or more. It was found that there was no part, and the positive and negative fluctuations in the slope value were due to noise. That is, in Comparative Example 2, no extreme value distinguished from noise was detected. Thus, it was confirmed that the thin film layer in the laminated film of Comparative Example 2 does not satisfy the seventh condition.

  For the laminated film of Comparative Example 2, a silicon distribution curve, an oxygen distribution curve, a carbon distribution curve, and an oxygen carbon distribution curve were prepared by the same method as in Example 1. As shown in FIG. 11, in Comparative Example 2, the absolute value of the difference between the maximum value and the minimum value of the atomic ratio of carbon in the carbon distribution curve is 5 at% in the range in which the presence or absence of the extreme value of the electron beam transmittance curve is determined. It was confirmed that it was less than. Thus, it was confirmed that the thin film layer in the laminated film of Comparative Example 2 did not satisfy the predetermined conditions regarding the first condition to the third condition.

In addition, the gas barrier properties of the laminated film of Comparative Example 2 were evaluated in the same manner as in Example 1. The water vapor permeability before bending was measured under two types of measurement conditions. Under the first measurement conditions, the measurement was performed using a water vapor transmission rate measuring device (manufactured by GTR Tech, model name “GTR Tech-30XASC”). Under the first measurement conditions, the temperature of the measurement environment is 40 ° C., the humidity on one side (low humidity side) of the laminated film is 0% RH, and the humidity on the other side (high humidity side) of the laminated film is 90% RH. Set. Under the first measurement condition, the water vapor permeability was 7.5 × 10 ⁻³ g / (m ² · day). Under the second measurement condition, measurement was performed using a water vapor transmission rate measuring device (manufactured by Lyssy, model name “Lyssy-L80-5000”). Under the second measurement conditions, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. Under the second measurement conditions, the water vapor permeability was a value below the detection limit.

The water vapor permeability after bending was measured using a water vapor permeability measuring machine (manufactured by Lyssy, model name “Lyssy-L80-5000”). In the measurement, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. The laminated film had a water vapor permeability of 0.27 g / (m ² · day) in a state where the film was bent and returned to a flat surface with a curvature radius of 8 mm. Thus, after the laminated film of Comparative Example 2 passed through the bent state, the gas barrier property was remarkably lowered. The laminated film of Comparative Example 2 had insufficient gas barrier properties after bending as compared with gas barrier properties generally required for battery cells.

(Comparative Example 3)
12A is an image showing a cross section of the barrier film in Comparative Example 3, and FIG. 12B is a graph showing electron beam transmittance with respect to the distance from the reference plane in the film thickness direction of the barrier film in Comparative Example 3. is there.

  In Comparative Example 3, a thin film layer is formed in the same manner as in Example 1 except that the supply amount of the source gas is 25 sccm in terms of 1 atm at 0 ° C. and the supply amount of the reaction gas is 1000 sccm in terms of 1 atm of 0 ° C. Thus, a comparative laminated film having the thin film layer as a barrier film was obtained. In the obtained laminated film, the thickness of the thin film layer was 180 nm.

About the laminated | multilayer film of the comparative example 3, it carried out similarly to Example 1, and created the electron beam transmittance curve which shows the relationship between the distance from the reference plane in a film thickness direction, and electron beam transmittance. In Comparative Example 3, the surface of the protective film formed on the sample was used as a reference plane in the film thickness direction. As shown in FIG. 12B, the electron beam transmittance curve in Comparative Example 2 does not have a clear extreme value. The range for determining the presence or absence of the extreme value of the electron beam transmittance curve is a range in which the distance from the reference plane in the film thickness direction is 40 nm or more and 140 nm or less. In the range in which the presence / absence of the extreme value of the electron beam transmittance curve is determined, the slope obtained by differentiating the electron beam transmittance curve with the distance from the reference plane in the film thickness direction was calculated. When the maximum value and the minimum value of the inclination were obtained, the maximum value of the inclination was 0.342 × 10 ⁻³ nm ⁻¹ and the minimum value of the inclination was −0.887 × 10 ⁻³ nm ⁻¹ . The absolute value of the difference between the maximum value and the minimum value of the slope was 1.23 × 10 ⁻³ nm ⁻¹ . In Comparative Example 3, when the positive / negative fluctuation of the slope value was examined by the above-described determination method of the presence / absence of the extreme value, the absolute value of the difference between the adjacent maximum value and the minimum value in the thickness direction variable was 0.03 or more. It was found that there was no part, and the positive and negative fluctuations in the slope value were due to noise. That is, in the comparative example 3, the extreme value distinguished from the noise was not detected. Thus, it was confirmed that the thin film layer in the laminated film of Comparative Example 3 does not satisfy the seventh condition.

In addition, the gas barrier properties of the laminated film of Comparative Example 3 were evaluated in the same manner as in Example 1. The water vapor permeability before bending was measured under two types of measurement conditions. Under the first measurement conditions, the measurement was performed using a water vapor transmission rate measuring device (manufactured by GTR Tech, model name “GTR Tech-30XASC”). Under the first measurement conditions, the temperature of the measurement environment is 40 ° C., the humidity on one side (low humidity side) of the laminated film is 0% RH, and the humidity on the other side (high humidity side) of the laminated film is 90% RH. Set. Under the first measurement condition, the water vapor transmission rate was 0.022 g / (m ² · day). The laminated film of Comparative Example 3 had insufficient gas barrier properties under the first measurement conditions as compared with gas barrier properties generally required for battery cells.
Under the second measurement condition, measurement was performed using a water vapor transmission rate measuring device (manufactured by Lyssy, model name “Lyssy-L80-5000”). Under the second measurement conditions, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. Under the second measurement conditions, the water vapor permeability was a value below the detection limit.

The water vapor permeability after bending was measured using a water vapor permeability measuring machine (manufactured by Lyssy, model name “Lyssy-L80-5000”). In the measurement, the temperature of the measurement environment was set to 40 ° C., the humidity on the low humidity side was set to 10% RH, and the humidity on the high humidity side was set to 100% RH. The laminated film had a water vapor permeability of 0.12 g / (m ² · day) in a state in which the film was bent and returned to a flat surface with a radius of curvature of 8 mm. Thus, after the laminated film of Comparative Example 3 passed through the bent state, the gas barrier property was remarkably lowered. The laminated film of Comparative Example 3 had insufficient gas barrier properties after bending as compared with gas barrier properties generally required for battery cells.

  As can be seen from the comparison between Examples 1 to 3 and Comparative Examples 1 to 3 as described above, the barrier film of the laminated film described in the above embodiment is required for the battery cell both before and after bending. Gas barrier properties can be expressed. Therefore, the battery cell of the above embodiment is suppressed from being deteriorated due to contact with oxygen gas or water vapor even after the battery cell is bent, and a decrease in battery cell performance or shortening of life is suppressed. Thus, according to the present invention, it is possible to achieve both high flexibility and high gas barrier properties in the battery cell.

  Next, an example of a device including the battery cell according to the present invention will be described with reference to FIG.

  The device 100A illustrated in FIG. 13A can be used as a lighting device or the like. The device 100 </ b> A includes an illumination unit 101, a power storage unit 102, and a power generation unit 103. In this example, each of the illumination part 101, the electrical storage part 102, and the electric power generation part 103 is a film form or plate shape. The power storage unit 102 is disposed between the lighting unit 101 and the power generation unit 103. One side of the illumination unit 101 is bonded to one side of the power storage unit 102. One side of the power generation unit 103 is bonded to the other side of the power storage unit 102 on the side opposite to the lighting unit 101 with respect to the power storage unit 102.

  The power generation unit 103 can generate electric power. The electric power generated by the power generation unit 103 can be supplied to at least one of the illumination unit 101 and the power storage unit 102. The power storage unit 102 of this example includes the battery cell described in the above embodiment. The power storage unit 102 can be charged with power generated by the power generation unit 103. The power storage unit 102 can supply power to the lighting unit 101 in a charged state. The illumination unit 101 can generate light by the supplied power, and can emit this light as illumination light from the surface opposite to the surface bonded to the power storage unit 102.

  The illumination unit 101 includes a light emitting element such as an organic EL element. This light-emitting element has a pair of electrodes, a light-emitting layer, and a pair of laminated films. The light emitting layer is disposed between the pair of electrodes. The pair of electrodes and the light emitting layer are sealed between the pair of laminated films. A pair of laminated film is comprised by the laminated film which concerns on the said embodiment, and has high flexibility and high gas-barrier property. The light emitting element of the illumination unit 101 emits light using at least one of the power generated in the power generation unit 103 and the power stored in the power storage unit 102. The illumination unit 101 emits light generated by the light emitting element as illumination light from a surface opposite to the surface bonded to the power storage unit 102.

  The power generation unit 103 includes power generation elements such as a photoelectric conversion element, a thermoelectric conversion element, and a fuel cell. The power generation unit 103 of this example includes an organic thin film solar cell. The power generation unit 103 is configured such that the organic thin-film solar cell receives light incident from the opposite side of the surface bonded to the power storage unit 102 and generates electric power. The organic thin film solar cell of this example has a transparent electrode, a reflective electrode, an active layer, and a pair of laminated films. The active layer is disposed between the transparent electrode and the reflective electrode. The organic thin film solar cell is configured to generate carriers in the active layer by light incident on the active layer through the transparent electrode. The transparent electrode, the reflective electrode, and the active layer are sealed between a pair of laminated films. A pair of laminated film is comprised by the laminated film which concerns on the said embodiment, and has high flexibility and high gas-barrier property.

  The device 100A includes the power storage unit 102 to which the battery cell according to the present invention is applied, so that high flexibility can be ensured and performance degradation or shortening of the life of the device 100A can be suppressed. Can do. Further, the illumination unit 101 and the power generation unit 103 are configured by applying the laminated film according to the above-described embodiment, and have high flexibility and high gas barrier properties. Can be remarkably suppressed.

The device 100B illustrated in FIG. 13B can be used as a lighting device or the like. The device 100B includes an illumination unit 101, a power storage unit 102, and a power generation unit 103. In this example, the illumination unit 101 and the power generation unit 103 are film-shaped or plate-shaped. One side of the illumination unit 101 is bonded to one side of the power generation unit 103. The illumination unit 101 emits illumination light from the surface opposite to the surface bonded to the power generation unit 103. The power generation unit 103 receives light incident from the surface opposite to the surface bonded to the illumination unit 101 and generates electric power. The power storage unit 102 is provided on the end surface of the device 100B on the side of the direction in which the illumination unit 101 and the power generation unit 103 face each other.
The device 100B includes the power storage unit 102 to which the battery cell according to the present invention is applied, so that high flexibility can be ensured and the performance degradation and shortening of the life of the device 100B can be significantly suppressed. can do.

  The device 100C illustrated in FIG. 13C can be used as a display device or the like. The device 100C includes a power storage unit 102, a power generation unit 103, a display unit 104, and a control unit 105. In this example, each of the power storage unit 102, the power generation unit 103, and the display unit 104 has a film shape or a plate shape. The power storage unit 102 is disposed between the display unit 104 and the power generation unit 103. One side of the display unit 104 is bonded to one side of the power storage unit 102. One side of the power generation unit 103 is bonded to the other side of the power storage unit 102 on the side opposite to the display unit 104 with respect to the power storage unit 102. The control unit 105 is provided on the end surface of the device 100C, which is lateral to the stacking direction in which the power storage unit 102, the power generation unit 103, and the display unit 104 are stacked.

The control unit 105 includes a volatile or nonvolatile memory element, a processing circuit, and the like. The control unit 105 controls the power storage unit 102, the power generation unit 103, and the display unit 104. The control unit 105 performs image processing on image data supplied from the outside or image data stored in the memory element as necessary, and supplies the image data to the display unit 104. The display unit 104 includes an organic EL display panel, a liquid surface display panel, an electrophoretic display panel, and the like.
The device 100C includes the power storage unit 102 to which the battery cell according to the present invention is applied, so that high flexibility can be ensured and the performance degradation and shortening of the life of the device 100C can be significantly suppressed. can do.

A device 100D illustrated in FIG. 13D can be used as a display device or the like. The device 100D includes a power storage unit 102, a power generation unit 103, a display unit 104, and a control unit 105. In this example, the power generation unit 103 and the display unit 104 have a film shape or a plate shape. One side of the display unit 104 is bonded to one side of the power generation unit 103. The display unit 104 emits image light from the surface opposite to the surface bonded to the power generation unit 103. The power generation unit 103 receives light incident from the surface opposite to the surface bonded to the display unit 104 and generates power. The power storage unit 102 and the control unit are provided on the end face of the device 100D on the side with respect to the direction in which the power generation unit 103 and the display unit 104 face each other.
The device 100D includes the power storage unit 102 to which the battery cell according to the present invention is applied, so that high flexibility can be ensured and the performance degradation and shortening of the life of the device 100D can be significantly suppressed. can do.

DESCRIPTION OF SYMBOLS 1 ... Battery cell, 2 ... Electrode body, 3, 4 ... Current collector, 5 ... Laminated film,
6 ... laminated film, 7 ... sealing material, 8 ... positive electrode active material layer (a pair of electrodes),
DESCRIPTION OF SYMBOLS 9 ... Negative electrode active material layer (a pair of electrodes), 10 ... Electrolyte layer, 11 ... Base material, 12 ... Barrier film,
13 ... base material, 14 ... barrier film, 50 ... manufacturing apparatus, 51 ... delivery roll,
52 ... take-up roll, 53-56 ... transport roll, 57, 58 ... film-forming roll,
59 ... Gas supply pipe, 60 ... Power source for plasma generation, 61, 62 ... Electrode,
63, 64 ... Magnetic field generator, 100A-100D ... Device, 101 ... Illumination part,
102 ... Power storage unit, 103 ... Power generation unit, 104 ... Display unit, 105 ... Control unit,
F ... Film, G ... Supply gas, SP ... Space

Claims (10)

A pair of electrodes; an electrolyte layer disposed between the pair of electrodes; and a barrier film having one or more thin film layers disposed on the opposite side of the electrolyte layer with respect to one of the pair of electrodes. With
At least one of the thin film layers contains silicon, oxygen and carbon, and the distance from the surface of the thin film layer in the film thickness direction and the sum of silicon atoms, oxygen atoms and carbon atoms Silicon distribution curves showing the relationship between the ratio of the amount of silicon atoms to the amount (atom ratio of silicon), the ratio of the amount of oxygen atoms (atom ratio of oxygen), and the ratio of the amount of carbon atoms (atom ratio of carbon), In the oxygen distribution curve and the carbon distribution curve, the following conditions (i) to (iii):
(I) the carbon distribution curve is substantially continuous;
(Ii) the carbon distribution curve has at least one extreme value;
(Iii) the absolute value of the difference between the maximum value and the minimum value of the atomic ratio of carbon in the carbon distribution curve is all 5 at% or more,
Furthermore, the battery cell in which the carbon distribution curve has two or more extreme values in the thin film layer .   In at least one of the thin film layers, an electron beam transmittance curve showing a relationship between a distance from the surface of the layer in the film thickness direction and the electron beam transmittance has at least one extreme value. Item 6. The battery cell according to Item 1.   The battery cell according to claim 1, wherein the carbon distribution curve has a maximum value and a minimum value.   The battery cell according to any one of claims 1 to 3, wherein an absolute value of a difference between a maximum value and a minimum value of an atomic ratio of silicon in the silicon distribution curve is less than 5 at%. A pair of electrodes; an electrolyte layer disposed between the pair of electrodes; and a barrier film having one or more thin film layers disposed on the opposite side of the electrolyte layer with respect to one of the pair of electrodes. With
A battery in which at least one of the thin film layers has an electron beam transmission curve showing a relationship between a distance from the surface of the layer in the film thickness direction and the electron beam transmission has at least one extreme value. cell. The roughness of the surface of the one electrode side of the barrier film is the following condition (iv):
(Iv) Rmax <200 nm, where Rmax is the maximum surface height,
The battery cell as described in any one of Claims 1-5 which satisfy | fills. A substrate disposed on the opposite side of the electrolyte layer with respect to one electrode of the pair of electrodes,
The battery cell according to claim 1, wherein the barrier film is formed on the base material.   The battery cell according to claim 7, wherein the barrier film is formed on each of both surfaces of the base material. A pair of base materials are arranged so as to sandwich the pair of electrodes, and the barrier film is formed on each of the pair of base materials,
One electrode of the pair of electrodes is formed on one substrate of the pair of substrates, and the other substrate of the pair of substrates on the other electrode of the pair of electrodes The battery cell according to any one of claims 1 to 8, wherein is adhered.   The battery cell according to claim 1, wherein the electrolyte layer is formed of a non-aqueous electrolyte.