All-solid-state energy storage device

Abstract

To provide an all-solid power storage element capable of suppressing breakage of an isolation layer.SOLUTION: The all-solid-state electricity storage element 1 includes a first electrode layer 10, a separation layer 20 laminated on the first electrode layer, and a second electrode layer 30 laminated on the separation layer, wherein an area of the first electrode layer is smaller than an area of the separation layer and an area of the second electrode layer. The isolation layer includes a facing portion 21 in which a portion of the second electrode layer facing the first electrode layer is laminated and a non-facing portion 22 in which a portion of the second electrode layer not facing the first electrode layer is laminated, and further includes an electronic insulating member 40 laminated on a surface of the non-facing portion on the first electrode layer side, wherein a ratio of an average thickness of the electronic insulating member in a lamination direction to the non-facing portion to an average thickness of the first electrode layer is 0.5 or more and 2.0 or less, and a Young's modulus of the electronic insulating member is 0.0020 MPa or more and 0.03 MPa or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an all-solid-state energy storage element. [Background technology]

[0002] Due to their high energy density, non-aqueous electrolyte secondary batteries, such as lithium ion secondary batteries, are widely used in electronic devices such as personal computers and communication terminals, as well as in automobiles. Non-aqueous electrolyte secondary batteries generally have a pair of electrically isolated electrodes and a non-aqueous electrolyte interposed between the electrodes, and are configured to charge and discharge by transferring charge-transporting ions between the electrodes. Other non-aqueous electrolyte storage elements besides non-aqueous electrolyte secondary batteries include capacitors such as lithium ion capacitors and electric double layer capacitors.

[0003] In recent years, all-solid-state energy storage elements have been proposed that use solid electrolytes, such as sulfide solid electrolytes, as the non-aqueous electrolyte instead of liquid electrolytes, such as organic solvents, in order to improve the safety of non-aqueous electrolyte energy storage elements. All-solid-state energy storage elements are sometimes manufactured by stacking a positive electrode (positive electrode layer) and a negative electrode (negative electrode layer) with a separator (solid electrolyte) sandwiched between them, and then pressing them in the stacking direction. In addition, in non-aqueous electrolyte energy storage elements, including all-solid-state energy storage elements, the area of ​​the positive electrode is sometimes made smaller than the area of ​​the negative electrode to prevent metals, etc., derived from charge-transporting ions, such as lithium ions, from depositing on the negative electrode.

[0004] When the area of ​​the positive electrode is smaller than that of the negative electrode, when the positive electrode and the negative electrode are stacked with the separator sandwiched therebetween and pressed in the stacking direction, the pressure applied by the press tends to be different between the portion of the separator facing both the positive electrode and the negative electrode and the other portion. As a result, damage such as cracks may occur in the portion of the separator facing the periphery of the positive electrode, etc. Such damage to the separator may cause a decrease in the insulation between the positive and negative electrodes.

[0005] As a technique for preventing damage to the separator layer caused by pressing during manufacturing, it has been proposed to place an insulator in the gap formed between the positive electrode and the negative electrode (Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-162353 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the inventors have found that even when an insulator is used as described above, it may be difficult to prevent damage to the isolation layer. Therefore, from the viewpoint of more reliably preventing damage to the isolation layer, further improvement in the configuration of the all-solid-state energy storage element is desired.

[0008] The present invention has been made in light of the above circumstances, and has an object to provide an all-solid-state energy storage element that can suppress damage to the isolation layer. [Means for solving the problem]

[0009] An all-solid-state energy storage element according to one aspect of the present invention comprises a first electrode layer, an isolation layer stacked on the first electrode layer, and a second electrode layer stacked on the isolation layer, wherein the area of ​​the first electrode layer is smaller than the area of ​​the isolation layer and the area of ​​the second electrode layer, the isolation layer has a facing portion where a portion of the second electrode layer facing the first electrode layer is stacked, and a non-facing portion where a portion of the second electrode layer that does not face the first electrode layer is stacked, and the element further comprises an electronic insulating member stacked on a surface of the non-facing portion facing the first electrode layer, wherein a ratio of an average thickness of the electronic insulating member in a stacking direction toward the non-facing portion to an average thickness of the first electrode layer is 0.5 or more and 2.0 or less, and the Young's modulus of the electronic insulating member is 0.002 MPa or more and 0.03 MPa or less. [Effects of the Invention]

[0010] An all-solid-state energy storage element according to one aspect of the present invention can suppress damage to the separator layer. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an all-solid-state energy storage element according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic plan view of the all-solid-state energy storage element of FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an all-solid-state energy storage element according to an embodiment other than that shown in FIG. [Figure 4] FIG. 4 is a schematic perspective view showing a part of the procedure for manufacturing the all-solid-state energy storage element of FIG. [Figure 5] FIG. 5 is a schematic side view showing a part of the procedure for manufacturing the all-solid-state energy storage element of FIG. [Figure 6] FIG. 6 is a schematic diagram showing an embodiment of an electricity storage device configured by assembling a plurality of all-solid-state electricity storage elements according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] First, an overview of the energy storage element disclosed in this specification will be described.

[0013] (1) An all-solid-state energy storage element according to one aspect of the present invention includes a first electrode layer, an isolation layer stacked on the first electrode layer, and a second electrode layer stacked on the isolation layer, wherein the area of ​​the first electrode layer is smaller than the area of ​​the isolation layer and the area of ​​the second electrode layer, the isolation layer has a facing portion where a portion of the second electrode layer facing the first electrode layer is stacked, and a non-facing portion where a portion of the second electrode layer that does not face the first electrode layer is stacked, and the element further includes an electronic insulating member stacked on a surface of the non-facing portion facing the first electrode layer, wherein a ratio of an average thickness of the electronic insulating member in a stacking direction toward the non-facing portion to an average thickness of the first electrode layer is 0.5 to 2.0, and the Young's modulus of the electronic insulating member is 0.002 MPa to 0.03 MPa.

[0014] The all-solid-state energy storage element described in (1) above can suppress damage to the separator. The reason for this effect is unclear, but the following reason is presumed. In an all-solid-state energy storage element in which a first electrode layer and a second electrode layer are stacked with an separator sandwiched therebetween and the area of ​​the first electrode layer is smaller than the areas of the separator and the second electrode layer, a difference in pressure is likely to occur between the portion of the separator facing both the first and second electrode layers and the other portion during pressing in the stacking direction, etc., resulting in the separator being easily damaged. In this regard, the all-solid-state energy storage element described in (1) above includes an electronic insulating member stacked on the surface of the non-facing portion of the separator facing the first electrode layer, thereby reducing the difference in pressure between the facing portion and the non-facing portion during pressing in the stacking direction, etc. In addition, the Young's modulus of the electronic insulating member is adjusted to a range of 0.002 MPa or more and 0.03 MPa or less, so that the pressure applied to the non-facing portion can be ensured while suppressing excessive pressure from being applied to the non-facing portion. Furthermore, the ratio of the average thickness of the electronic insulating member in the stacking direction to the non-facing portion to the average thickness of the first electrode layer is within an appropriate range. Therefore, it is presumed that the all-solid-state energy storage element described in (1) above can suppress damage to the isolation layer.

[0015] In the present invention, the "area of ​​the first electrode layer" refers to the area of ​​the active material layer of the first electrode layer when the first electrode layer has a substrate and an active material layer laminated on the substrate, and the area of ​​the active material layer is different from the area of ​​the substrate (for example, when the active material layer is laminated on a part of the substrate). Similarly, the "area of ​​the second electrode layer" refers to the area of ​​the active material layer of the second electrode layer when the second electrode layer has a substrate and an active material layer laminated on the substrate, and the area of ​​the active material layer is different from the area of ​​the substrate. The "portion facing the first electrode layer" refers to the portion facing the active material layer of the first electrode layer when the first electrode layer has a substrate and an active material layer laminated on the substrate. The "area of ​​the first electrode layer," "area of ​​the second electrode layer," and "area of ​​the isolation layer" refer to the area when viewed in the stacking direction.

[0016] In the present invention, the term "electronic insulating material" refers to a material having a volume resistivity of 10 7The volume resistivity is a value measured in accordance with JIS-H-0505 (1975), and the same applies to the rest of the description in this specification.

[0017] The average thickness of the first electrode layer and the electronic insulating member included in the all-solid-state energy storage element is measured according to the following procedure. First, the all-solid-state energy storage element is discharged at a constant current of 0.05 C to the lower limit voltage during normal use. Next, a cross section of the all-solid-state energy storage element cut in the thickness direction (stacking direction) is observed with a scanning electron microscope, and the thickness of each is measured. The cross sections of the first electrode layer and the electronic insulating member are each prepared by exposing the cross section using an ion milling method. Note that the "average thickness" refers to the average value of thicknesses measured at any five locations, and this also applies to the rest of the description in this specification.

[0018] In the present invention, the Young's modulus of the electronic insulating material is measured by disassembling an all-solid-state energy storage device, stacking multiple electronic insulating materials to a total thickness of 1 mm or more, and cutting them into a test piece of a predetermined size (e.g., 3.0 cm x 3.5 cm). Using a Shimadzu Autograph (registered trademark) "AGX-V" material testing machine, the test piece is compressed at a compression rate of 1 mm / min in an atmosphere of 25°C. A graph is plotted with the horizontal axis representing the displacement [%] in the thickness direction of the test piece and the vertical axis representing the pressure (stress) [MPa]. A regression line is calculated for the change in pressure from when pressure detection begins until the test piece's displacement reaches 5%. The slope of the regression line calculated as pressure [MPa] / displacement [%] is taken as the Young's modulus.

[0019] (2) In the all-solid-state energy storage element described in (1) above, the first electrode layer may be a positive electrode layer, and the second electrode layer may be a negative electrode layer.

[0020] In the all-solid-state energy storage element described above in (2), the area of ​​the positive electrode layer is smaller than the area of ​​the separator layer and the area of ​​the negative electrode layer, and therefore, it is easy to prevent metals derived from charge transport ions from being deposited in the negative electrode layer. Also, from the viewpoint of preventing damage to the separator layer, this is a preferred embodiment of the present invention.

[0021] (3) In the all-solid-state energy storage element according to (1) or (2), the electronic insulating member may be a porous body.

[0022] In the all-solid-state energy storage element described in (3) above, the electronic insulating member is porous, and thus the electronic insulating member can be deformed to a thickness nearly equal to that of the first electrode layer when pressed in the stacking direction, etc. This reduces the pressure difference between the non-facing portion and the facing portion of the isolation layer, thereby further suppressing damage to the isolation layer. In the present invention, the term "porous body" refers to a material having a porosity of 10% or more. "Porosity" is measured using the following procedure. The electronic insulating material to be measured is prepared using the same procedure as described above for measuring the average thickness. The electronic insulating material is cut to an appropriate size to form a test piece. The mass of the cut test piece is divided by the apparent volume to determine the bulk density. The apparent volume refers to the volume including voids, and can be determined as the product of the average thickness and area of ​​the electronic insulating material. The porosity (%) of the test piece is calculated using the formula: porosity = (1 - true density / bulk density (g / cc)) × 100. Here, the true density (g / mL) of the test piece is measured using a density meter (Micromeritics' Accupyk II 1340).

[0023] (4) In the all-solid-state energy storage element described in (3) above, the electronic insulating member may be in a mesh shape.

[0024] In the all-solid-state energy storage element described in (4) above, the electronic insulating member is mesh-shaped, so that the electronic insulating member can be more easily deformed to a thickness nearly equal to that of the first electrode layer when pressed in the stacking direction, etc. This reduces the pressure difference between the non-facing portion and the facing portion of the isolating layer, thereby further suppressing damage to the isolating layer.

[0025] (5) In the all-solid-state energy storage element according to (3) or (4), the porosity of the electronic insulating member may be 30% or more and 80% or less.

[0026] In the all-solid-state energy storage element described in (5) above, the porosity of the electronic insulating member is within an appropriate range, and therefore, when pressing in the stacking direction, etc., the pressure applied from the electronic insulating member to the non-facing portion can be ensured, and the pressure difference applied between the non-facing portion and the facing portion of the isolation layer can be easily reduced.

[0027] (6) In the all-solid-state energy storage element according to any one of (1) to (5) above, the electronic insulating member may contain polyamide or fluororesin.

[0028] In the all-solid-state energy storage element described in (6) above, the physical properties of the electronic insulating member can be easily made suitable from the viewpoint of ensuring pressure applied to the non-facing portions while suppressing excessive pressure from being applied to the non-facing portions when pressing in the stacking direction, etc. Therefore, damage to the separator can be easily suppressed.

[0029] (7) In the all-solid-state energy storage element described in (1) to (6) above, the electronic insulating member may be configured in a frame shape so as to surround the periphery of the first electrode layer when viewed in the stacking direction to the non-opposing portion.

[0030] In the all-solid-state energy storage element described in (7) above, the pressure applied from the electronic insulating member to the non-facing portion can be easily made uniform over the entire surface of the non-facing portion when pressing in the stacking direction, etc., and therefore damage to the isolating layer can be easily suppressed.

[0031] Hereinafter, an all-solid-state energy storage element, a manufacturing method for an all-solid-state energy storage element, an energy storage device, and other embodiments according to one embodiment of the present invention will be described in detail. Note that the lower and upper limits of each numerical range described in the embodiments of the present invention can be combined in any combination.

[0032] First Embodiment [All-solid-state energy storage element] As a first embodiment of the all-solid-state energy storage element of the present invention, an all-solid-state secondary battery will be described below as a specific example. The all-solid-state energy storage element 1 shown in Figures 1 and 2 includes a first electrode layer 10, an isolation layer 20 laminated on the first electrode layer 10, and a second electrode layer 30 laminated on the isolation layer 20. That is, the first electrode layer 10, the isolation layer 20, and the second electrode layer 30 are laminated in this order. The area of ​​the first electrode layer 10 is smaller than the area of ​​the isolation layer 20 and the area of ​​the second electrode layer 30. The isolation layer 20 has a facing portion 21 where a portion of the second electrode layer 30 facing the first electrode layer 10 is laminated, and a non-facing portion 22 where a portion of the second electrode layer 30 not facing the first electrode layer 10 is laminated. The all-solid-state energy storage element 1 further includes an electronic insulating member 40 laminated on the surface of the non-facing portion 22 facing the first electrode layer 10. The ratio of the average thickness of the electronic insulating member 40 in the stacking direction to the non-facing portion 32 to the average thickness of the first electrode layer 10 is 0.5 or more and 2.0 or less. The Young's modulus of the electronic insulating member 40 is 0.002 MPa or more and 0.03 MPa or less. In this embodiment, the average thickness of the first electrode layer 10 is the total average thickness of the positive electrode substrate 11 and the positive electrode active material layer 12, which will be described later. Furthermore, when an intermediate layer is provided between the positive electrode substrate 11 and the positive electrode active material layer 12, as will be described later, the average thickness of the first electrode layer 10 is the total average thickness of the positive electrode substrate 11, the intermediate layer, and the positive electrode active material layer 12.

[0033] The all-solid-state energy storage element 1 is manufactured, for example, through a process of pressing the first electrode layer 10, the isolation layer 20, and the second electrode layer 30 in the stacking direction. By having the above-mentioned configuration, the all-solid-state energy storage element 1 can suppress damage to the isolation layer 20 due to pressing in the stacking direction, particularly during manufacturing. That is, the all-solid-state energy storage element 1 can suppress damage to the isolation layer 20.

[0034] In this embodiment, the first electrode layer 10 is a positive electrode layer, and the second electrode layer 30 is a negative electrode layer. By having the first electrode layer 10 as a positive electrode layer and the second electrode layer 30 as a negative electrode layer in this manner, it is easy to suppress the deposition of metals and the like derived from charge transport ions in the negative electrode layer. In the following description of this specification, the first electrode layer 10 is also referred to as a positive electrode layer, and the second electrode layer 30 is also referred to as a negative electrode layer.

[0035] In this embodiment, the first electrode layer 10 has a positive electrode substrate 11 and a positive electrode active material layer 12 laminated on the positive electrode substrate 11. The second electrode layer 30 has a negative electrode substrate 31 and a negative electrode active material layer 32 laminated on the negative electrode substrate 31. An intermediate layer may be provided between the positive electrode substrate 11 and the positive electrode active material layer 12. Similarly, an intermediate layer may be provided between the negative electrode substrate 31 and the negative electrode active material layer 32. The all-solid-state energy storage element 1 according to one embodiment of the present invention may further include other members such as a container. In the all-solid-state energy storage element 1 shown in FIGS. 1 and 2, other members such as a container are omitted.

[0036] The all-solid-state energy storage element 1 according to one embodiment of the present invention may further include, for example, a positive electrode lead, a positive electrode external terminal, a negative electrode lead, and a negative electrode external terminal. The positive electrode lead and the negative electrode lead are housed in a container. The positive electrode external terminal and the negative electrode external terminal are provided outside the container. The first electrode layer 10 (positive electrode layer) is electrically connected to the positive electrode external terminal via the positive electrode lead. The second electrode layer 30 (negative electrode layer) is electrically connected to the negative electrode external terminal via the negative electrode lead. The positive electrode lead may be welded or bonded to the positive electrode substrate 11. The positive electrode substrate 11 and the positive electrode lead extending protruding from the positive electrode substrate 11 may constitute the same member. The negative electrode lead may be welded or bonded to the negative electrode substrate 31. The negative electrode substrate 31 and the negative electrode lead extending protruding from the negative electrode substrate 31 may constitute the same member.

[0037] In this embodiment, the separator 20 is laminated on the positive electrode active material layer 12, and the negative electrode active material layer 32 is laminated on the separator 20. In other words, the positive electrode substrate 11, the positive electrode active material layer 12, the separator 20, the negative electrode active material layer 32, and the negative electrode substrate 31 are laminated in this order. In other words, the negative electrode active material layer 32 is laminated on one surface (the surface on the negative electrode layer side) of the opposing portion 21 of the separator 20, and the positive electrode active material layer 12 is laminated on the other surface (the surface on the positive electrode layer side). In addition, the negative electrode active material layer 32 is laminated on one surface (the surface on the negative electrode layer side) of the non-opposing portion 22 of the separator 20, and the electronic insulating member 40 is laminated on the other surface (the surface on the positive electrode layer side) without the positive electrode active material layer 12 laminated on it. The first electrode layer 10, the separator 20, and the second electrode layer 30 are laminated in close contact with each other to form a single laminate as a whole.

[0038] In this embodiment, the first electrode layer 10, the separator layer 20, and the second electrode layer 30 are, for example, sheet-shaped. The positive electrode active material layer 12, the separator layer 20, and the negative electrode active material layer 32 are preferably rectangular in plan view. Furthermore, the laminate formed by the first electrode layer 10, the separator layer 20, and the second electrode layer 30 is preferably rectangular in plan view. Such a configuration can improve the manufacturing efficiency of the all-solid-state energy storage element 1. Here, the rectangular shape may be a square, a rectangle, or a strip.

[0039] In this embodiment, the positive electrode active material layer 12 is laminated on the isolation layer 20 so that the non-facing portion 22 is provided in a frame shape so as to surround the periphery of the positive electrode active material layer 12 in a plan view. In other words, the facing portion 21 of the isolation layer 20 is provided in the center of the isolation layer 20, and the non-facing portion 22 is provided in a frame shape so as to surround the periphery of the facing portion 21. The facing portion 21 is preferably rectangular in a plan view, and the non-facing portion 22 is preferably frame-shaped in a plan view. By providing the non-facing portion 22 in this manner, it is easy to make the pressure applied to the non-facing portion 22 uniform over the entire surface of the non-facing portion 22.

[0040] In this embodiment, the electronic insulating member 40 is configured in a frame shape surrounding the periphery of the first electrode layer 10 when viewed in the stacking direction (plan view) of the isolating layer 20 to the non-facing portion 22 (see FIG. 2 ). The outer edge of the positive electrode substrate 11 and the outer edge of the positive electrode active material layer 12 are aligned. In other words, the positive electrode active material layer 12 and the positive electrode substrate 11 are stacked on the first electrode layer 10 side (positive electrode layer side) of the facing portion 21 of the isolating layer 20, and the electronic insulating member 40 is stacked on the first electrode layer 10 side (positive electrode layer side) of the non-facing portion 22 of the isolating layer 20. In plan view, the first electrode layer 10 is preferably rectangular, and the electronic insulating member 40 is preferably frame-shaped. By providing the first electrode layer 10 and the electronic insulating member 40 in this manner, the pressure applied from the electronic insulating member 40 to the non-facing portion 22 is easily uniformed across the entire surface of the non-facing portion 22, which makes it easy to prevent damage to the isolating layer 20.

[0041] The lower limit of the ratio of the average thickness of the electronic insulating member 40 in the stacking direction to the non-facing portion 22 to the average thickness of the first electrode layer 10 is 0.5, preferably 0.6, more preferably 0.7, and even more preferably 0.8, and may be 0.9, 1.0, or 0.95, as described above. On the other hand, the upper limit of the ratio is 2.0, preferably 1.8, and may be 1.6, 1.4, 1.2, or 1.1, as described above. When the ratio is equal to or greater than the lower limit, the pressure applied to the non-facing portion 22 due to stress caused by contraction of the electronic insulating member 40 during pressing in the stacking direction, etc., can be easily ensured, and the difference in pressure applied between the facing portion 21 and the non-facing portion 22 can be suppressed. When the ratio is equal to or less than the upper limit, the application of excessive pressure to the non-facing portion 22 due to the stress during pressing in the stacking direction, etc., can be suppressed, and the difference in pressure applied between the facing portion 21 and the non-facing portion 22 can be suppressed. If the ratio is less than 1.0, the average thickness of the electronic insulating member 40 is less than the average thickness of the first electrode layer 10, and therefore, there is a possibility that the first electrode layer 10 will be pressed first when pressing in the stacking direction, etc. However, even in such a case, if the ratio is equal to or greater than the lower limit, pressure may also be applied to the opposing portion 21, and it is thought that the difference in pressure applied to the opposing portion 21 and the non-opposing portion 22 is likely to become small.

[0042] The average thickness of the electronic insulating member 40 in the stacking direction on the non-facing portion 22 may be 40 μm or more and 1,000 μm or less. The lower limit of the average thickness of the electronic insulating member 40 in the stacking direction on the non-facing portion 22 may be 60 μm, 80 μm, 100 μm, or 150 μm. The upper limit of the average thickness of the electronic insulating member 40 in the stacking direction on the non-facing portion 22 may be 500 μm, 400 μm, 300 μm, 200 μm, or 180 μm.

[0043] The thickness of the electronic insulating member 40 in the stacking direction to the non-facing portion 22 is preferably in the range of 0.9 to 1.1 times the average thickness, and more preferably in the range of 0.95 to 1.05 times, from the viewpoint of uniformly distributing the pressure applied to the non-facing portion 22.

[0044] The side surface 13 of the outer edge of the first electrode layer 10 may contact the side surface of the electronic insulating member 40 surrounding the first electrode layer 10, or there may be a gap between the side surface 13 of the outer edge of the first electrode layer 10 and the side surface of the electronic insulating member 40. Contact between the side surface 13 of the outer edge of the first electrode layer 10 and the side surface of the electronic insulating member 40 facilitates increased manufacturing efficiency when forming the electronic insulating member 40 by coating or other processes. However, this may increase the risk of the first electrode layer 10 being pressed by the electronic insulating member 40 or of the pressure being applied to the non-facing portion 21 becoming uneven during pressing in the stacking direction, etc. As a result, the first electrode layer 10 or the isolation layer 20 may be more susceptible to damage. However, in the present invention, the Young's modulus and other properties of the electronic insulating member 40 are adjusted within an appropriate range, making it difficult for the stress of the electronic insulating member 40 to become excessively large during pressing in the stacking direction, etc., thereby preventing damage to the first electrode layer 10 or the isolation layer 20. That is, when the side surface 13 of the outer edge of the first electrode layer 10 and the side surface of the electronic insulating member 40 are in contact with each other, the advantage of the present invention that damage to the isolation layer 20 can be suppressed can be obtained, and manufacturing efficiency can be easily improved.

[0045] As described above, the lower limit of the Young's modulus of the electronic insulating member 40 is 0.002 MPa, more preferably 0.003 MPa, even more preferably 0.004 MPa, and may be 0.005 MPa, 0.010 MPa, 0.015 MPa, or 0.020 MPa. Meanwhile, the upper limit of the Young's modulus of the electronic insulating member 40 is 0.03 MPa, more preferably 0.028 MPa, even more preferably 0.027 MPa, and may be 0.025 MPa, 0.020 MPa, 0.015 MPa, or 0.010 MPa. When the Young's modulus is equal to or greater than the lower limit, it is easy to ensure that the pressure applied to the non-facing portion 22 due to the stress caused by contraction of the electronic insulating member 40 during pressing in the stacking direction, etc. is maintained. Furthermore, when the Young's modulus is equal to or less than the upper limit, it is possible to prevent excessive pressure from being applied to the non-facing portion 22 due to the stress during pressing in the stacking direction, etc.

[0046] The lower limit of the ratio of the area of ​​the non-facing portion 22 to the total area of ​​the facing portion 21 and the non-facing portion 22 in a plan view is preferably 0.05, more preferably 0.07, and even more preferably 0.09. On the other hand, the upper limit of the ratio is preferably 0.50, more preferably 0.45, and even more preferably 0.40. When the ratio is equal to or greater than the lower limit, it is easy to prevent metals derived from charge transport ions from depositing in the negative electrode layer. Furthermore, when the ratio is equal to or less than the upper limit, it is possible to ensure the output of the all-solid-state energy storage element and easily prevent damage to the isolation layer 20.

[0047] The lower limit of the ratio of the area of ​​the electronic insulating member 40 to the area of ​​the non-facing portion 22 in a plan view may be 0.6, but is preferably 0.8, more preferably 0.9, even more preferably 0.95, and particularly preferably 0.99. Furthermore, the electronic insulating member 40 is preferably laminated on the isolating layer 20 over substantially the entire surface of the non-facing portion 22 in a plan view, and more preferably laminated on the isolating layer 20 over at least the entire surface of the non-facing portion 22. Having this ratio equal to or greater than the lower limit makes it possible to easily prevent damage to the isolating layer 20. On the other hand, the upper limit of the ratio is not particularly limited, and may be 2.5, 2.0, 1.5, or 1.0.

[0048] The upper limit of the ratio of the area of ​​the electronic insulating member 40 to the area of ​​the facing portion 21 in a plan view (the ratio of the area of ​​the electronic insulating member 40 to the area of ​​the positive electrode active material layer 12) is preferably 1.50 or 1.25, but may also be 0.80, 0.70, 0.65, or 0.60. When the ratio is equal to or less than the upper limit, damage to the separator layer 20 can be easily suppressed. Furthermore, from the viewpoint of suppressing the deposition of metals and the like derived from charge transport ions in the negative electrode layer, the lower limit of the ratio is preferably 0.05, more preferably 0.10, and even more preferably 0.20.

[0049] The main components of the all-solid-state energy storage element 1 will be described in detail below.

[0050] (1st electrode layer) As described above, the first electrode layer 10 (positive electrode layer) has the positive electrode substrate 11 and the positive electrode active material layer 12 laminated on the positive electrode substrate 11 directly or via an intermediate layer.

[0051] The thickness of the positive electrode layer is appropriately set depending on the application of the all-solid-state energy storage element 1, etc. The average thickness of the positive electrode layer may be, for example, 30 μm or more and 1,000 μm or less. The lower limit of the average thickness of the positive electrode layer may be 50 μm, 80 μm, 100 μm, or 200 μm. The upper limit of the average thickness of the positive electrode layer may be 500 μm, 400 μm, 300 μm, 200 μm, or 100 μm. The average thickness of the positive electrode layer is the average thickness of a portion where the positive electrode active material layer 12 is laminated on the positive electrode substrate 11 directly or via an intermediate layer. When the positive electrode substrate 11 has both a portion where the positive electrode active material layer 12 is laminated on both sides and a portion where the positive electrode active material layer 12 is laminated on only one side, the average thickness of the portion where the positive electrode active material layer 12 is laminated on both sides of the positive electrode substrate 11 is referred to as the average thickness.

[0052] The positive electrode substrate 11 has electrical conductivity. In this specification, "having electrical conductivity" means that the volume resistivity is 10 -2 This means that the resistance is Ω·cm or less.

[0053] Examples of materials for the positive electrode substrate 11 include metals such as aluminum, titanium, iron, and alloys thereof (such as stainless steel). Among these, aluminum or an aluminum alloy is preferred from the viewpoints of potential resistance, high electronic conductivity, and cost.

[0054] The positive electrode substrate 11 has a shape such as a sheet, plate, or strip. The positive electrode substrate 11 may be in the form of a foil, a vapor-deposited film, a mesh, a porous material, or the like, and is preferably in the form of a foil. The positive electrode substrate 11 may be, for example, an aluminum foil or an aluminum alloy foil.

[0055] The average thickness of the positive electrode substrate 11 may be, for example, 3 μm or more and 50 μm or less. The lower limit of the average thickness of the positive electrode substrate 11 may be 5 μm, 8 μm, 10 μm, or 15 μm. The upper limit of the average thickness of the positive electrode substrate 11 may be 40 μm, 30 μm, 20 μm, or 15 μm.

[0056] The intermediate layer is a layer disposed between the positive electrode substrate 11 and the positive electrode active material layer 12. The intermediate layer contains, for example, a conductive agent and a binder. When the intermediate layer contains a conductive agent, the contact resistance between the positive electrode substrate 11 and the positive electrode active material layer 12 can be reduced. Examples of the conductive agent and binder used in the intermediate layer include the same conductive agent and binder used in the positive electrode active material layer 12 described below.

[0057] The positive electrode active material layer 12 contains a positive electrode active material. The positive electrode active material layer 12 contains optional components such as a solid electrolyte, a conductive agent, a binder, a thickener, and a filler as necessary. The positive electrode active material layer 12 may be formed from a positive electrode mixture containing a positive electrode active material and other optional components. As in the all-solid-state energy storage element 1 of FIG. 1 , the positive electrode active material layer 12 may be provided on only one side of a positive electrode substrate 11 having a shape such as a sheet. In another embodiment, the positive electrode active material layer 12 may be provided on both sides of the positive electrode substrate 11.

[0058] Known positive electrode active materials can be used for the positive electrode active material. Materials capable of absorbing and releasing lithium ions are typically used for the positive electrode active material of lithium ion secondary batteries. Examples of positive electrode active materials include lithium transition metal composite oxides, polyanion compounds, chalcogen compounds, sulfur-based materials, and lithium oxide. One or more positive electrode active materials can be used.

[0059] Examples of the transition metal element contained in the lithium transition metal composite oxide include nickel, cobalt, and manganese. The lithium transition metal composite oxide may also contain a typical metal element such as aluminum. Examples of the lithium transition metal composite oxide include lithium transition metal composite oxides having an α-NaFeO2 crystal structure and lithium transition metal composite oxides having a spinel crystal structure.

[0060] Lithium transition metal composite oxides with an α-NaFeO2 type crystal structure include Li 1+α Ma 1-α 02 (Ma is a metal element other than lithium containing one or more transition metal elements, where 0≦α<1). Ma preferably contains one or more of Ni, Co and Mn. The total content of Ni, Co and Mn relative to Ma ((Ni+Co+Mn) / Ma) is preferably 90 mol % or more, more preferably 98 mol % or more.

[0061] Lithium transition metal composite oxides with spinel-type crystal structures include Li β Examples include those represented by Mb2O4 (Mb is a metal element other than lithium containing one or more transition metal elements, and 0<β≦1.2). Mb preferably contains Mn. The content of Mn relative to Mb (Mn / Mb) is preferably 50 mol % or more, and more preferably 80 mol % or more.

[0062] A polyanion compound is a compound composed of a polyanion (i.e., a polyvalent oxoacid anion) and a cation. The polyanion compound preferably contains lithium cations and transition metal cations as cations. Examples of the polyanion compound include LiFePO4, LiMnPO4, LiMn x Fe 1-x PO4(0 < x < 1), LiNiPO4, LiCoPO4, Li3V2(PO4)3, Li2MnSiO4, Li2CoPO4F, and the like. The surface of the particles of the polyanion compound may be coated with another material (such as a carbon material described later).

[0063] Examples of the chalcogen compound include titanium disulfide, molybdenum disulfide, molybdenum dioxide, and the like.

[0064] Examples of the sulfur-based material include elemental sulfur, metal sulfides such as lithium sulfide, organic disulfide compounds, and organic sulfur compounds such as carbon sulfide compounds.

[0065] Atoms or polyanions in these materials that are cathode active materials may be partially substituted with atoms or anion species composed of other elements. The surfaces of these materials may be coated with other materials.

[0066] The positive electrode active material is usually particulate. The average particle size of the positive electrode active material is preferably, for example, 0.1 μm to 20 μm. Setting the average particle size of the positive electrode active material above the lower limit facilitates the production and handling of the positive electrode active material. Setting the average particle size of the positive electrode active material below the upper limit improves the electronic conductivity of the positive electrode active material layer 12. When a composite of the positive electrode active material and another material is used, the average particle size of the composite is taken as the average particle size of the positive electrode active material. The term "average particle size" refers to the value at which the volume-based cumulative distribution (D50) reaches 50% as calculated in accordance with JIS-Z-8819-2 (2001) based on the particle size distribution measured by laser diffraction / scattering in a diluted solution of particles diluted with a solvent in accordance with JIS-Z-8825 (2013). Methods for obtaining particles of the positive electrode active material and the negative electrode active material described below with a predetermined particle size can be known, for example, using a pulverizer, a classifier, or the like.

[0067] The content of the positive electrode active material in the positive electrode active material layer 12 is preferably 50% by mass or more and 99% by mass or less, more preferably 70% by mass or more and 98% by mass or less, and may be 80% by mass or more and 95% by mass or less. By setting the content of the positive electrode active material within the above range, it is possible to achieve both a high energy density and manufacturability of the positive electrode active material layer 12.

[0068] The solid electrolyte refers to an electrolyte that maintains a solid state at 25°C under a nitrogen atmosphere. Examples of solid electrolytes include sulfide solid electrolytes, oxide solid electrolytes, dry polymer electrolytes, gel polymer electrolytes, and pseudo-solid electrolytes, with sulfide solid electrolytes being preferred. The solid electrolyte may be a solid electrolyte other than an oxide solid electrolyte. The upper limit of the oxygen element content in the solid electrolyte may be 10 mol%, 1 mol%, or 0.1 mol%. The solid electrolyte may be a crystalline solid electrolyte or an amorphous solid electrolyte. A crystalline solid electrolyte refers to a solid electrolyte in which a peak derived from the solid electrolyte is observed in the X-ray diffraction pattern. An amorphous solid electrolyte refers to a solid electrolyte in which a halo pattern is observed in the X-ray diffraction pattern, with substantially no peaks other than those derived from the raw materials being observed. One or more solid electrolytes may be used.

[0069] The sulfide solid electrolyte preferably contains at least sulfur element and further contains lithium element. The sulfide solid electrolyte preferably has lithium ion conductivity. The sulfide solid electrolyte preferably also contains phosphorus element and preferably further contains a halogen element. The sulfide solid electrolyte preferably contains at least one of bromine element and iodine element as the halogen element.

[0070] When the sulfide solid electrolyte is a crystalline solid electrolyte, its crystal structure may be an argyrodite crystal structure, a Li3PS4 crystal structure, a Li4P2S6 crystal structure, or a Li7P3S 11 Crystal structure, Li 10 GeP2S 12Examples of sulfide solid electrolytes include sulfide solid electrolytes having crystalline structures such as a crystalline structure, a Thio-LISICON type crystalline structure, an inverse fluorite type crystalline structure, a crystalline structure (High Ion Conduction Phase: HICP) having diffraction peaks in the ranges of diffraction angle 2θ of 19.9° ± 0.5° and 29.3° ± 0.5° in an X-ray diffraction pattern using CuKα rays, a crystalline structure (Low Ion Conduction Phase: LICP) having diffraction peaks in the ranges of diffraction angle 2θ of 21.0 ± 0.5° and 28.0 ± 0.5° in an X-ray diffraction pattern using CuKα rays, and a crystalline structure having different diffraction peaks in the ranges of diffraction angle 2θ of 17.9° ± 0.5° or 19.1° ± 0.5°, a diffraction angle 2θ of 29.1° ± 0.5°, and a diffraction angle 2θ of 29.8° ± 0.5°, wherein any of these diffraction peaks is the maximum diffraction peak.

[0071] Examples of sulfide solid electrolytes include Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-LiCl, Li2S-P2S5-LiBr, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-P2S5-Li3N, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, and Li2S-P2S5-Z. m S 2n (where m and n are positive numbers, and Z is Ge, Zn, or Ga.), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y (where x and y are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, and In.) Li 10 GeP2S 12 etc.

[0072] In the positive electrode active material layer 12, the solid electrolyte may form a complex with the positive electrode active material. Such a complex may further contain other components (e.g., a conductive agent) in addition to the solid electrolyte and the positive electrode active material.

[0073] When the positive electrode active material layer 12 contains a solid electrolyte, the content of the solid electrolyte in the positive electrode active material layer 12 is preferably 5% by mass or more and 50% by mass or less, may be 10% by mass or more and 40% by mass or less, or may be 15% by mass or more and 30% by mass or less.

[0074] Conductive agents are usually components made of materials that have electrical conductivity. Even if the volume resistivity of a conductive agent cannot be measured directly, it is possible to measure the volume resistivity by measuring the volume resistivity of the conductive agent when the volume resistivity is 10 -2 Conductive agents are materials known to have a resistivity of Ω·cm or less. Examples of conductive agents include carbon materials, metals, and conductive ceramics. Carbon materials are materials whose primary constituent element is carbon. The primary constituent element refers to the element with the highest content by mass. For example, the carbon content in a carbon material may be 80% by mass or more, 90% by mass or more, 95% by mass, 99% by mass, or 99.9% by mass or more. The carbon material is preferably a carbon material other than an uncarbonized polymer compound. Examples of carbon materials include graphite, non-graphitic carbon, and graphene-based carbon. Examples of non-graphitic carbon include carbon nanofiber, pitch-based carbon fiber, and carbon black. Examples of carbon black include furnace black, acetylene black, and ketjen black. Examples of graphene-based carbon include graphene, carbon nanotubes (CNT), and fullerene. Conductive agents may be in the form of powder, fiber, or the like. The conductive agent may be one or more kinds. The conductive agent may be a composite of these materials. For example, a composite material of carbon black and CNT may be used.

[0075] The content of the conductive agent in the positive electrode active material layer 12 is preferably 0.1% by mass to 10% by mass, more preferably 1% by mass to 9% by mass, and even more preferably 3% by mass to 8% by mass. The upper limit of the content of the conductive agent may be 5%, 4%, or 3% by mass. By setting the content of the conductive agent within the above range, it is possible to increase the energy density of the all-solid-state energy storage element 1, etc.

[0076] Examples of the binder include a water-based binder and an organic solvent-based binder.

[0077] The aqueous binder is a binder that dissolves or disperses in water. The aqueous binder may be a binder that dissolves or disperses at 1 part by mass or more in 100 parts by mass of water at 20°C. When forming the positive electrode active material layer 12 using a positive electrode mixture paste whose dispersion medium is water or a mixed solvent mainly composed of water, an aqueous binder (a water-soluble or water-dispersible polymer material) can be used. Here, the term "main component" refers to the component that accounts for the largest proportion by mass (e.g., a component that accounts for 50% by mass or more), and this also applies to the rest of the description in this specification. Examples of aqueous binders include polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, polytetrafluoroethylene, styrene-butadiene rubber, polyethylene, polypropylene, nitrile-butadiene rubber, and cellulose.

[0078] The organic solvent-based binder is a binder that dissolves or disperses in an organic solvent (e.g., N-methylpyrrolidone). The organic solvent-based binder may be a binder that dissolves or disperses at 1 part by mass or more in 100 parts by mass of an organic solvent (e.g., N-methylpyrrolidone) at 20°C. When the positive electrode active material layer 12 is formed using a positive electrode mixture paste whose dispersion medium is an organic solvent or a mixed solvent mainly containing an organic solvent, an organic solvent-based binder (a polymer material that is soluble or dispersible in an organic solvent) can be used. Examples of organic solvent-based binders include polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, a copolymer of ethylene and vinyl alcohol, polyacrylonitrile, polyphosphazene, polysiloxane, polyvinyl acetate, polymethyl methacrylate, polystyrene, polycarbonate, polyamide, polyimide, polyamideimide, a crosslinked polymer of cellulose and chitosan pyrrolidone carboxylate, and chitosan derivatives.

[0079] The binder may be a fluororesin (polytetrafluoroethylene, polyvinylidene fluoride, etc.), a polyolefin (polyethylene, polypropylene, etc.), an elastomer (ethylene propylene diene rubber, styrene butadiene rubber, fluororubber, etc.), a polysaccharide polymer (cellulose, chitosan derivatives, etc.), etc. One or more types of binders may be used.

[0080] The content of the binder in the positive electrode active material layer 12 is preferably 0.1% by mass to 10% by mass, more preferably 1% by mass to 9% by mass, and more preferably 3% by mass to 8% by mass. The upper limit of the binder content may be 5%, 4%, or 3% by mass. By setting the binder content within the above range, it is possible to stably hold the positive electrode active material. The technology disclosed herein can also be implemented in an embodiment in which the positive electrode active material layer 12 does not contain a binder.

[0081] Examples of thickeners include polysaccharide polymers such as carboxymethyl cellulose and methyl cellulose. When the thickener has a functional group that reacts with lithium or the like, the functional group may be deactivated in advance by methylation or the like. The thickener may also function as a binder. One or more types of thickeners may be used. When the positive electrode active material layer 12 contains a thickener, the content of the thickener in the positive electrode active material layer 12 is preferably 0.1% by mass or more and 8% by mass or less, more preferably 5% by mass or less, and even more preferably 2% by mass or less. The technology disclosed herein may also be implemented in an embodiment in which the positive electrode active material layer 12 does not contain a thickener.

[0082] The filler is not particularly limited. The filler may be a component other than the positive electrode active material, solid electrolyte, conductive agent, binder, and thickener, and may be intentionally added. The filler may be added to fill gaps in the positive electrode active material layer 12, or may be added for other purposes. The filler may be an organic substance such as polyolefin, or an inorganic substance such as an inorganic oxide, hydroxide, or carbonate. One or more fillers may be used. When the positive electrode active material layer 12 contains a filler, the content of the filler in the positive electrode active material layer 12 may be 0.1% by mass or more and 8% by mass or less, typically preferably 5% by mass or less, and more preferably 2% by mass or less. The technology disclosed herein may also be implemented in an embodiment in which the positive electrode active material layer 12 does not contain a filler.

[0083] The positive electrode active material layer 12 may further contain other components in addition to the positive electrode active material, solid electrolyte, conductive agent, binder, thickener, and filler. The other components include those unintentionally generated in the positive electrode active material layer 12. The positive electrode active material layer 12 may also contain unintentionally contained impurities as the other components, as long as the effects of the present invention are achieved. The upper limit of the content of the other components in the positive electrode active material layer 12 may be 10% by mass, 5%, 2%, 1%, 0.1%, or 0.01% by mass. The upper limit of the content of the unintentionally generated components in the positive electrode active material layer 12 may be 10% by mass, 5%, 2%, 1%, 0.1%, or 0.01% by mass. The upper limit of the content of unintentionally contained impurities in the positive electrode active material layer 12 may be 10 mass %, 5 mass %, 2 mass %, 1 mass %, 0.1 mass %, or 0.01 mass %.

[0084] The thickness of the positive electrode active material layer 12 and the like are set appropriately depending on the type of positive electrode active material, the application of the all-solid-state energy storage device 1, and the like. The average thickness of one layer of the positive electrode active material layer 12 may be, for example, 5 μm or more and 1,000 μm or less. The lower limit of the average thickness of one layer of the positive electrode active material layer 12 may be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, or 100 μm. The upper limit of the average thickness of one layer of the positive electrode active material layer 12 may be 800 μm, 500 μm, 200 μm, 100 μm, 80 μm, 60 μm, or 40 μm. The mass per unit area of ​​one layer of the positive electrode active material layer 12 is, for example, 4 mg / cm. 2 More than 100mg / cm 2 The lower limit of the mass per unit area of ​​one layer of the positive electrode active material layer 12 may be 6 mg / cm or less. 2 , 8 mg / cm 2 or 10 mg / cm 2 The upper limit of the mass per unit area of ​​one layer of the positive electrode active material layer 12 is 50 mg / cm. 2 , 20 mg / cm 2 , 15 mg / cm 2 , 12 mg / cm 2 or 10 mg / cm 2 may be.

[0085] (2nd electrode layer) As described above, the second electrode layer 30 (negative electrode layer) has the negative electrode substrate 31 and the negative electrode active material layer 32 laminated on the negative electrode substrate 31 directly or via an intermediate layer.

[0086] The thickness of the negative electrode layer is appropriately set depending on the application of the all-solid-state energy storage element 1, etc. The average thickness of the negative electrode layer may be, for example, 30 μm or more and 1,000 μm or less. The lower limit of the average thickness of the negative electrode layer may be 50 μm, 100 μm, or 200 μm. The upper limit of the average thickness of the negative electrode layer may be 500 μm, 400 μm, 300 μm, 200 μm, or 100 μm. The average thickness of the negative electrode layer is the average thickness of a portion where the negative electrode active material layer 32 is laminated on the negative electrode substrate 31 directly or via an intermediate layer. When the negative electrode substrate 31 has both a portion where the negative electrode active material layer 32 is laminated on both sides and a portion where the negative electrode active material layer 32 is laminated on only one side, the average thickness of the negative electrode layer is the average thickness of the portion where the negative electrode active material layer 32 is laminated on both sides of the negative electrode substrate 31.

[0087] The negative electrode substrate 31 is conductive. Examples of materials for the negative electrode substrate 31 include metals such as copper, nickel, iron, and alloys thereof (such as stainless steel), and carbon materials. Among these, copper or a copper alloy is preferred.

[0088] The negative electrode substrate 31 has a shape such as a sheet, plate, or strip. The negative electrode substrate 31 may be in the form of a foil, a vapor-deposited film, a mesh, a porous material, or the like, and is preferably a foil. The negative electrode substrate 31 may be, for example, a copper foil or a copper alloy foil.

[0089] The average thickness of the negative electrode substrate 31 may be, for example, 2 μm or more and 35 μm or less. The lower limit of the average thickness of the negative electrode substrate 31 may be 3 μm, 4 μm, 5 μm, or 10 μm. The upper limit of the average thickness of the negative electrode substrate 31 may be 30 μm, 20 μm, 15 μm, or 10 μm.

[0090] The structure of the intermediate layer of the negative electrode layer is not particularly limited, and can be selected from the structures exemplified for the intermediate layer of the positive electrode layer, for example.

[0091] The negative electrode active material layer 32 contains a negative electrode active material. The negative electrode active material layer 32 may contain optional components such as a solid electrolyte, a conductive agent, a binder, a thickener, and a filler, as necessary. The optional components such as the solid electrolyte, the conductive agent, the binder, the thickener, and the filler can be selected from the materials exemplified for the positive electrode layer. The negative electrode active material layer 32 may be formed from a negative electrode mixture containing a negative electrode active material and other optional components. As in the all-solid-state energy storage element 1 of FIG. 1 , the negative electrode active material layer 32 may be provided on only one side of the negative electrode substrate 31 having a shape such as a sheet. In another embodiment, the negative electrode active material layer 32 may be provided on both sides of the negative electrode substrate 31.

[0092] The negative electrode active material can be a known negative electrode active material. A material capable of absorbing and releasing lithium ions is typically used as the negative electrode active material for lithium ion secondary batteries. Examples of the negative electrode active material include metallic lithium; metals or semimetals such as silicon and tin; metal oxides or semimetal oxides such as silicon oxide, titanium oxide, and tin oxide; and Li4Ti5O. 12 , LiTiO 2、 Examples of the negative electrode active material include titanium-containing oxides such as TiNbO; polyphosphate compounds; silicon carbide; and carbon materials such as graphite and non-graphitic carbon. The surface of the graphite may be coated with other materials such as non-graphitic carbon. One or more negative electrode active materials may be used.

[0093] "Graphite" refers to the graphite that has an average lattice spacing (d 002 ) is a carbon material with a particle size of 0.33 nm or more and less than 0.34 nm. Graphite includes natural graphite and artificial graphite.

[0094] "Non-graphitic carbon" refers to carbon that has an average lattice spacing (d 002) refers to a carbon material in which the particle size is 0.34 nm or more and 0.42 nm or less. Non-graphitizable carbon includes non-graphitizable carbon and graphitizable carbon. "Non-graphitizable carbon" refers to a carbon material in which the particle size is 0.34 nm or more and 0.42 nm or less. 002 The term "easily graphitizable carbon" refers to a carbon material having a particle size of 0.36 nm or more and 0.42 nm or less. 002 This refers to carbon materials with a particle size of 0.34 nm or more and less than 0.36 nm.

[0095] Here, the "discharged state" of a carbon material refers to a state in which the carbon material, which is a negative electrode active material, is discharged so that lithium ions that can be absorbed and released during charging and discharging are sufficiently released from the carbon material. For example, this refers to a state in which the open circuit voltage of a half cell using a negative electrode containing a carbon material as a negative electrode active material as a working electrode and metallic lithium as a counter electrode is 0.7 V or higher.

[0096] The negative electrode active material may be particulate. The average particle size of the negative electrode active material may be, for example, 1 nm or more and 100 μm or less. When the negative electrode active material is a carbon material, a titanium-containing oxide, a polyphosphate compound, or the like, the average particle size may be 1 μm or more and 100 μm or less. When the negative electrode active material is Si, Sn, Si oxide, Sn oxide, or the like, the average particle size may be 1 nm or more and 1 μm or less. By setting the average particle size of the negative electrode active material to be equal to or greater than the above-mentioned lower limit, the negative electrode active material can be easily produced or handled. By setting the average particle size of the negative electrode active material to be equal to or less than the above-mentioned upper limit, the electronic conductivity of the negative electrode active material layer 32 is improved.

[0097] The content of the negative electrode active material in the negative electrode active material layer 32 is, for example, preferably 60% by mass or more and 99% by mass or less, and more preferably 90% by mass or more and 98% by mass or less. By setting the content of the negative electrode active material within the above range, it is possible to achieve both a high energy density and manufacturability of the negative electrode active material layer 32.

[0098] When the negative electrode active material is a metal such as metallic lithium, the negative electrode active material layer 32 may be in the form of a foil. The metallic lithium may exist as pure metallic lithium consisting essentially of elemental lithium, or may exist as a lithium alloy containing other metal elements. When the negative electrode active material is a metal such as metallic lithium, the content of elemental lithium in the negative electrode active material layer 32 may be 90% by mass or more, 99% by mass or more, or even 100% by mass.

[0099] When the negative electrode active material layer 32 contains a conductive agent, the content of the conductive agent in the negative electrode active material layer 32 is preferably 1% by mass or more and 10% by mass or less, and more preferably 3% by mass or more and 9% by mass or less. The content of the conductive agent in the negative electrode active material layer 32 may be 5% by mass or less, or may be 2% by mass or less. The technology disclosed herein can also be implemented in an embodiment in which the negative electrode active material layer 32 does not contain a conductive agent.

[0100] When the negative electrode active material layer 32 contains a solid electrolyte, the content of the solid electrolyte is preferably 5% by mass or more and 90% by mass or less, and may be 10% by mass or more and 70% by mass or less, or may be 20% by mass or more and 50% by mass or less.

[0101] When the negative electrode active material layer 32 contains a binder, the content of the binder in the negative electrode active material layer 32 is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.5% by mass or more and 8% by mass or less. The content of the binder in the negative electrode active material layer 32 may be 5% by mass or less, or may be 2% by mass or less. The technology disclosed herein can also be implemented in an embodiment in which the negative electrode active material layer 32 does not contain a binder.

[0102] When the negative electrode active material layer 32 contains a thickener, the content of the thickener in the negative electrode active material layer 32 is preferably 0.1% by mass to 10% by mass, and more preferably 0.5% by mass to 8% by mass. The content of the thickener in the negative electrode active material layer 32 may be 5% by mass or less, or may be 2% by mass or less. The technology disclosed herein can also be implemented in an embodiment in which the negative electrode active material layer 32 does not contain a thickener.

[0103] The filler in the negative electrode active material layer 32 may be a component other than the negative electrode active material, solid electrolyte, conductive agent, binder, and thickener, and may be an intentionally contained component. The filler may be contained as a component to fill gaps in the negative electrode active material layer 32, or may be contained for another purpose. When the negative electrode active material layer 32 contains a filler, the content of the filler in the negative electrode active material layer 32 can be 0.1% by mass or more and 8% by mass or less, and typically 5% by mass or less is preferable, and 2% by mass or less is more preferable. The technology disclosed herein can also be implemented in an embodiment in which the negative electrode active material layer 32 does not contain a filler.

[0104] The negative electrode active material layer 32 may further contain other components in addition to the negative electrode active material, solid electrolyte, conductive agent, binder, thickener, and filler. The other components include those unintentionally generated in the negative electrode active material layer 32. The negative electrode active material layer 32 may also contain unintentionally contained impurities as the other components, as long as the effects of the present invention are achieved. The upper limit of the content of the other components in the negative electrode active material layer 32 may be 10% by mass, 5%, 2%, 1%, 0.1%, or 0.01% by mass. The upper limit of the content of the unintentionally generated components in the negative electrode active material layer 32 may be 10% by mass, 5%, 2%, 1%, 0.1%, or 0.01% by mass. The upper limit of the content of impurities unintentionally contained in the negative electrode active material layer 32 may be 10 mass %, 5 mass %, 2 mass %, 1 mass %, 0.1 mass %, or 0.01 mass %.

[0105] The thickness and the like of the negative electrode active material layer 32 are set appropriately depending on the type of negative electrode active material, the application of the all-solid-state energy storage element 1, and the like. The average thickness of one layer of the negative electrode active material layer 32 may be, for example, 5 μm or more and 1,000 μm or less. The lower limit of the average thickness of one layer of the negative electrode active material layer 32 may be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, or 100 μm. The upper limit of the average thickness of one layer of the negative electrode active material layer 32 may be 800 μm, 500 μm, 200 μm, 100 μm, 80 μm, 60 μm, or 40 μm. The mass per unit area of ​​one layer of the negative electrode active material layer 32 is, for example, 2 mg / cm. 2 More than 50mg / cm 2 The lower limit of the mass per unit area of ​​one layer of the negative electrode active material layer 32 is 3 mg / cm. 2 , 4 mg / cm 2 , 5 mg / cm 2 or 6 mg / cm 2 The upper limit of the mass per unit area of ​​one layer of the negative electrode active material layer 32 is 30 mg / cm. 2 , 20 mg / cm 2 , 15 mg / cm 2 , 12 mg / cm 2 or 10 mg / cm 2 may be.

[0106] (isolation layer) The separator 20 usually contains a solid electrolyte. The solid electrolyte can be selected from the materials exemplified for the positive electrode active material layer 12. The content of the solid electrolyte in the separator 20 is preferably 70% by mass or more and 100% by mass or less. The content of the solid electrolyte in the separator 20 may be 90% by mass or more, 99% by mass or more, or 100% by mass.

[0107] The separator 20 may contain optional components such as additives (e.g., phosphate compounds such as LiPO, oxides, and halogen compounds), binders, thickeners, and fillers. The optional components such as binders, thickeners, and fillers can be selected from the materials exemplified for the positive electrode active material layer 12.

[0108] The average thickness of the separator 20 is preferably 1 μm or more and 100 μm or less, more preferably 2 μm or more and 50 μm or less, and even more preferably 3 μm or more and 20 μm or less. By setting the average thickness of the separator 20 to be equal to or more than the above lower limit, it is possible to insulate the positive electrode and the negative electrode with high reliability. By setting the average thickness of the separator 20 to be equal to or less than the above upper limit, it is possible to increase the energy density of the all-solid-state energy storage element 1.

[0109] The above-described preferred configurations for the composition and average thickness of the isolation layer 20 can be similarly applied to the opposing portions 21 and 22 of the isolation layer 20 .

[0110] (Electronic insulating materials) The electronic insulating member 40 has electronic insulation properties and is laminated on the non-facing portion 22 of the isolation layer 20 as described above. The electronic insulating member 40 may or may not have ion conductivity. However, it is preferable that the electronic insulating member 40 does not electrochemically react with charge transport ions such as lithium ions.

[0111] The electronic insulating member 40 is preferably a porous body. When the electronic insulating member 40 is a porous body, the electronic insulating member 40 can be deformed to a thickness nearly equal to that of the first electrode layer 10 (positive electrode layer) during pressing in the stacking direction, etc. This reduces the pressure difference applied between the non-facing portion 22 and the facing portion 21 of the isolation layer 20, further suppressing damage to the isolation layer 20.

[0112] The porous electronic insulating member 40 is preferably mesh-shaped. Furthermore, the mesh-shaped openings are preferably arranged regularly. The electronic insulating member 40 is also preferably formed by stacking mesh-shaped sheets. By using a mesh-shaped electronic insulating member 40, when the electronic insulating member 40 is pressed, the voids in the mesh can be uniformly compressed before the stress of the material constituting the electronic insulating member 40 itself is exerted. Furthermore, the electronic insulating member 40 can be easily deformed to a thickness nearly equal to that of the first electrode layer 10 (positive electrode layer). This reduces the pressure difference between the non-facing portion 22 and the facing portion 21 of the isolation layer 20, further suppressing damage to the isolation layer 20.

[0113] The lower limit of the average fiber diameter of the fibers forming the mesh of the mesh-shaped electronic insulating member 40 is preferably 10 μm, more preferably 20 μm, and even more preferably 30 μm. On the other hand, the upper limit of the average fiber diameter of the fibers forming the mesh of the electronic insulating member 40 is preferably 150 μm, more preferably 130 μm, and even more preferably 110 μm. When the average fiber diameter of the fibers forming the mesh of the electronic insulating member 40 is within the above range, the physical properties of the electronic insulating member 40 tend to be favorable from the viewpoint of suppressing a sudden change in pressure applied from the electronic insulating member 40 to the non-facing portions 22 of the isolating layer 20 during pressing in the stacking direction, for example.

[0114] The lower limit of the porosity of the electronic insulating member 40 is preferably 30%, more preferably 35%, and may be 40%, 45%, 50%, 55%, 60%, or 65%. On the other hand, the upper limit of the porosity of the electronic insulating member 40 is preferably 80%, and may be 70%, 65%, 60%, 55%, 50%, or 45%. When the porosity of the electronic insulating member 40 is equal to or greater than the above lower limit, the pressure difference between the non-facing portion 22 and the facing portion 21 of the isolation layer 20 can be easily reduced during pressing in the stacking direction, etc. Furthermore, when the porosity of the electronic insulating member 40 is equal to or greater than the above upper limit, it is easy to ensure the pressure applied from the electronic insulating member 40 to the non-facing portion 22 during pressing in the stacking direction, etc.

[0115] The lower limit of the melting point of the electronic insulating member 40 is preferably 100°C or higher, more preferably 120°C or higher, and even more preferably 140°C or higher, from the viewpoint that pressing is generally performed using a hot press machine at a relatively high temperature during production. The melting point is preferably 20°C higher, more preferably 40°C higher, and even more preferably 50°C higher than the set temperature of the hot press machine. On the other hand, the upper limit of the melting point of the electronic insulating member 40 is not particularly limited, but may be, for example, 300°C.

[0116] The electronic insulating member 40 preferably contains a resin, more preferably contains a resin as a main component, and even more preferably consists essentially of a resin. When the electronic insulating member 40 contains a resin, the physical properties of the electronic insulating member 40 are easily optimized, from the viewpoint of ensuring pressure applied to the non-facing portion 22 while preventing excessive pressure from being applied to the non-facing portion 22 during pressing in the stacking direction, etc. Examples of resins include polyamides and fluororesins, as well as the materials exemplified as binders in the positive electrode active material layer 12 (thermoplastic resins, elastomers, polysaccharide polymers, acrylic resins). Among these, polyamides or fluororesins are preferred. Examples of polyamides include nylon 6, nylon 66, and nylon 612. Of these, nylon 66 and nylon 612 are preferred, with nylon 66 being more preferred. Examples of fluororesins include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and perfluoroalkoxyalkane (PFA). Of these, PVDF and PFA are preferred, with PFA being more preferred.

[0117] (container) The container accommodates the first electrode layer 10 (positive electrode layer) and the second electrode layer 30 (negative electrode layer) in its internal space. Materials for the container include metal materials such as aluminum and stainless steel, and resin materials, with metal materials being preferred from the standpoint of strength, etc. Composite materials of metal and resin materials can also be used.

[0118] The shape of the container is not particularly limited, and may be cylindrical, rectangular (square), disk-like, etc. The container may also be in the shape of a sheet formed from a metal resin composite film.

[0119] [Shape, uses, etc. of all-solid-state energy storage devices] The shape of the all-solid-state energy storage element 1 in this embodiment is not particularly limited. The all-solid-state energy storage element 1 may be, for example, a prismatic battery, a flat battery, or the like.

[0120] There are no particular limitations on the use of the all-solid-state energy storage element 1 in this embodiment. The all-solid-state energy storage element 1 can be used, for example, as a power source for automobiles such as electric vehicles, hybrid vehicles, and plug-in hybrid vehicles, a power source for electronic devices such as personal computers and communication terminals, a power source for power storage, etc.

[0121] The all-solid-state energy storage element 1 in this embodiment may be used singly or in plural. When the required output and required voltage are small, the all-solid-state energy storage element 1 may be used singly. On the other hand, when at least one of the required output and required voltage is large, the all-solid-state energy storage element 1 may be used as an energy storage device combined with other energy storage elements. In an energy storage device in which a plurality of energy storage elements are combined, it is sufficient that at least one energy storage element included in the energy storage device is the all-solid-state energy storage element 1 in this embodiment. The energy storage device will be described in detail later.

[0122] In the all-solid-state energy storage element 1 of this embodiment, for example, the container may be constrained so as to maintain a constant thickness, or may not be constrained in this way. Furthermore, the container may be constrained so as to apply a constant load to it. When the container is constrained, expansion of the container due to charge / discharge cycles or the like is suppressed, and deterioration of charge / discharge performance may be suppressed. When the container is constrained, a load may or may not be applied to the positive electrode layer and the negative electrode layer in the container. For example, the all-solid-state energy storage element 1 or the energy storage device may be provided with a constraining member that performs such constraining.

[0123] [Manufacturing method of all-solid-state energy storage element] The manufacturing method of the all-solid-state storage element 1 is not particularly limited, but may include, for example, preparing a first electrode layer 10 (positive electrode layer), preparing a second electrode layer 30 (negative electrode layer), stacking an isolation layer 20 on the second electrode layer 30, arranging the first electrode layer 10 and the electronic insulating member 40 on the isolation layer 20, and pressing the first electrode layer 10 and the electronic insulating member 40.

[0124] The first electrode layer 10 may be produced by laminating a positive electrode active material layer 12 on a positive electrode substrate 11. The positive electrode active material layer 12 can be laminated by applying a paste-like positive electrode mixture to the positive electrode substrate 11, drying it, and then pressing it. The pressing may be, for example, hot pressing, and the same applies to the following description. The first electrode layer 10 can also be produced by transferring a positive electrode active material layer 12 formed into a predetermined shape to the positive electrode substrate 11.

[0125] The second electrode layer 30 may be produced by laminating the negative electrode active material layer 32 on the negative electrode substrate 31. The lamination of the negative electrode active material layer 32 can be performed by applying a paste-like negative electrode mixture to the negative electrode substrate 31, drying it, and then pressing it. The pressing after applying the negative electrode mixture may be performed simultaneously with pressing the separator-forming material described below. The second electrode layer 30 can also be produced by transferring the negative electrode active material layer 32 formed into a predetermined shape onto the negative electrode substrate 31.

[0126] The separator 20 can be laminated on the second electrode layer 30, for example, by laminating an separator-forming material containing a solid electrolyte on the negative electrode active material layer 32 and then pressing the laminate. The separator 20 can also be laminated on the second electrode layer 30 by transferring the separator 20 formed into a predetermined shape onto the negative electrode active material layer 32.

[0127] 4, disposing the first electrode layer 10 and the electronic insulating member 40 on the isolation layer 20 may be performed by disposing the first electrode layer 10 on the isolation layer 20, and then disposing a frame-shaped electronic insulating member 40 so as to surround the periphery of the first electrode layer 10. Alternatively, disposing the first electrode layer 10 and the electronic insulating member 40 on the isolation layer 20 may be performed by disposing a frame-shaped electronic insulating member 40 on the isolation layer 20, and then disposing the first electrode layer 10 within the frame. The electronic insulating member 40 may be disposed, for example, by applying a resin paste or the like, in which a resin serving as a raw material for the electronic insulating member 40 is dissolved in a solvent, to the surface of the isolation layer 20, and then drying the solvent contained in the resin paste or the like.

[0128] Pressing the first electrode layer 10 and the electronic insulating member 40 may be joining the first electrode layer 10 and the electronic insulating member 40 to the isolation layer 20 by pressing. The first electrode layer 10 and the electronic insulating member 40 can be pressed simultaneously by hot pressing at a predetermined temperature or higher. In this case, the set temperature of the hot pressing machine is preferably 80°C or higher, more preferably 120°C or higher, and even more preferably 160°C or higher.

[0129] Thereafter, the electrode body in which the first electrode layer 10, the second electrode layer 30, the isolation layer 20, and the electronic insulating member 40 are laminated is appropriately provided with leads, etc. by a known method, and the electrode body is housed in a container by a known method, thereby manufacturing the all-solid-state energy storage element 1.

[0130] Second Embodiment [All-solid-state energy storage element] The all-solid-state energy storage element 2 shown in FIG. 3 includes a first electrode layer 102, an isolation layer 20 laminated on the first electrode layer 102, and a second electrode layer 30 laminated on the isolation layer 20. That is, the first electrode layer 102, the isolation layer 20, and the second electrode layer 30 are laminated in this order. The area of ​​the first electrode layer 102 (the area of ​​a positive electrode active material layer 122 described below) is smaller than the area of ​​the isolation layer 20 and the area of ​​the second electrode layer 30. The isolation layer 20 has a facing portion 21 where a portion of the second electrode layer 30 facing the first electrode layer 102 is laminated, and a non-facing portion 22 where a portion of the second electrode layer 30 not facing the first electrode layer 102 is laminated. The all-solid-state energy storage element 1 further includes an electronic insulating member 402 laminated on a surface of the non-facing portion 22 facing the first electrode layer 102. The ratio of the average thickness of the electronic insulating member 40 in the stacking direction toward the non-facing portion 32 to the average thickness of the first electrode layer 102 is 0.5 or more and 2.0 or less. The Young's modulus of the electronic insulating member 402 is 0.002 MPa or more and 0.03 MPa or less. In this embodiment, the average thickness of the first electrode layer 102 is the total average thickness of the positive electrode substrate 112 and the positive electrode active material layer 122, which will be described later. Furthermore, when an intermediate layer is provided between the positive electrode substrate 112 and the positive electrode active material layer 122, as will be described later, the average thickness of the first electrode layer 102 is the total average thickness of the positive electrode substrate 112, the intermediate layer, and the positive electrode active material layer 122.

[0131] 1 and 2 except that the positive electrode substrate 112 of the first electrode layer 102 is laminated on both the positive electrode active material layer 122 and the electronic insulating member 402. Since the components of the all-solid-state energy storage element 2 other than the first electrode layer 102 and the electronic insulating member 402 are the same as the components of the all-solid-state energy storage element 1, they are denoted by the same numbers and description thereof is omitted. Furthermore, unless otherwise specified, the preferred configuration of each component is the same as that of the all-solid-state energy storage element 1.

[0132] In this embodiment, the first electrode layer 102 has a positive electrode substrate 112 and a positive electrode active material layer 122 laminated on the positive electrode substrate 112. An intermediate layer may be provided between the positive electrode substrate 112 and the positive electrode active material layer 122. The separator 20 is laminated on the positive electrode active material layer 122, and the negative electrode active material layer 32 is laminated on the separator 20. In other words, the positive electrode substrate 112, the positive electrode active material layer 122, the separator 20, the negative electrode active material layer 32, and the negative electrode substrate 31 are laminated in this order. The positive electrode active material layer 122 is laminated on the separator 20 so that a frame-shaped non-facing portion 22 is provided surrounding the periphery of the positive electrode active material layer 122 in a plan view.

[0133] In this embodiment, the electronic insulating member 402 is configured in a frame shape so as to surround the periphery of the positive electrode active material layer 122 when viewed in the stacking direction (plan view) on the non-facing portion 22 of the isolating layer 20. As described above, the positive electrode substrate 112 is stacked on both the positive electrode active material layer 122 and the electronic insulating member 402. In this case, the outer edge of the electronic insulating member 402 and the outer edge of the positive electrode substrate 112 are aligned. In other words, the positive electrode active material layer 122 and the positive electrode substrate 112 are stacked on the first electrode layer 102 side (positive electrode layer side) of the facing portion 21 of the isolating layer 20, and the electronic insulating member 402 and the positive electrode substrate 112 are stacked on the first electrode layer 102 side (positive electrode layer side) of the non-facing portion 22 of the isolating layer 20.

[0134] In the all-solid-state energy storage element 2, as in the all-solid-state energy storage element 1, damage to the isolation layer 20 can be suppressed.

[0135] The side surface 122a of the outer edge of the positive electrode active material layer 122 may be in contact with the side surface of the electronic insulating member 402 that surrounds the periphery of the positive electrode active material layer 122, or there may be a gap between the side surface 122a of the outer edge of the positive electrode active material layer 122 and the side surface of the electronic insulating member 402. When the side surface 122a of the outer edge of the positive electrode active material layer 122 is in contact with the side surface of the electronic insulating member 402, it is possible to enjoy the advantage of the present invention that damage to the isolation layer 20 can be suppressed, while also easily improving manufacturing efficiency.

[0136] [Manufacturing method of all-solid-state energy storage element] The manufacturing method of the all-solid-state energy storage element 2 is not particularly limited, but may include, for example, preparing a first electrode layer 102 (positive electrode layer), arranging an electronic insulating member 402 on a positive electrode substrate 112, preparing a second electrode layer 30 (negative electrode layer), stacking an isolation layer 20 on the second electrode layer 30, arranging the first electrode layer 102 and the electronic insulating member 402 on the isolation layer 20, and pressing the first electrode layer 102 and the electronic insulating member 402.

[0137] The first electrode layer 102 may be produced by laminating a positive electrode active material layer 122 on a positive electrode substrate 112. The lamination of the positive electrode active material layer 122 can be performed by applying a paste-like positive electrode mixture to the positive electrode substrate 112 while leaving an uncoated portion, drying the mixture, and then pressing. The application of the positive electrode mixture to the positive electrode substrate 112 may be, for example, intermittent application. The first electrode layer 102 can also be produced by transferring a positive electrode active material layer 122 formed into a predetermined shape to the positive electrode substrate 112 while leaving an uncoated portion.

[0138] Arranging the electronic insulating member 402 on the positive electrode substrate 112 may mean arranging a frame-shaped electronic insulating member 402 in an uncoated portion of the positive electrode substrate 112 so as to surround the periphery of the positive electrode active material layer 122. The electronic insulating member 402 may be arranged, for example, by applying a resin paste or the like, in which a resin serving as a raw material for the electronic insulating member 402 is dissolved in a solvent, to the uncoated portion of the positive electrode substrate 112, and then drying the solvent contained in the resin paste or the like. By arranging the electronic insulating member 402 on the positive electrode substrate 112 in this manner, a laminate in which the first electrode layer 102 and the electronic insulating member 402 are stacked is formed.

[0139] The steps of producing the second electrode layer 30 and laminating the isolation layer 20 on the second electrode layer 30 are the same as those in the first embodiment, and therefore a description thereof will be omitted.

[0140] 5 , disposing the first electrode layer 102 and the electronic insulating member 402 on the isolation layer 20 may be disposing the laminate of the first electrode layer 102 and the electronic insulating member 40 on the isolation layer 20. In this case, the surface of the laminate opposite to the positive electrode substrate 112 side is disposed on the isolation layer 20.

[0141] Pressing the first electrode layer 102 and the electronic insulating member 402 may be joining the stack of the first electrode layer 102 and the electronic insulating member 402 to the isolation layer 20 by pressing. The pressing of the first electrode layer 102 and the electronic insulating member 402 may be performed by hot pressing at a predetermined temperature or higher. In this case, the set temperature of the hot pressing machine is preferably 80°C or higher, more preferably 120°C or higher, and even more preferably 160°C or higher.

[0142] Thereafter, the all-solid-state energy storage element 2 can be manufactured by appropriately arranging leads, etc. on the electrode body in which the first electrode layer 102, the second electrode layer 30, the isolation layer 20, and the electronic insulating member 402 are laminated by a known method, and by housing the electrode body in a container by a known method.

[0143] <Electricity storage device> 6 includes a plurality of power storage units 50. Each power storage unit 50 includes a plurality of electrically connected all-solid-state power storage elements 1. The power storage device 60 may include a bus bar (not shown) that electrically connects the plurality of all-solid-state power storage elements 1, a bus bar (not shown) that electrically connects the plurality of power storage units 50, etc. The power storage unit 50 or the power storage device 60 may include a state monitoring device (not shown) that monitors the state of one or more all-solid-state power storage elements 1.

[0144] <Other embodiments> The all-solid-state energy storage element of the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention. For example, the configuration of one embodiment can be added to the configuration of another embodiment, and part of the configuration of one embodiment can be replaced with the configuration of another embodiment or well-known technology. Furthermore, part of the configuration of one embodiment can be deleted. Also, well-known technology can be added to the configuration of one embodiment.

[0145] In the above embodiment, the all-solid-state energy storage element is used as a chargeable and dischargeable non-aqueous electrolyte secondary battery, but the all-solid-state energy storage element may be of any type, shape, size, capacity, etc. The present invention can also be applied to various secondary batteries, electric double layer capacitors, lithium ion capacitors, and other capacitors.

[0146] When the positive electrode substrate of the first electrode layer is laminated on both the positive electrode active material layer and the electronic insulating member as in the second embodiment, the ratio of the average thickness of the electronic insulating member in the stacking direction toward the non-facing portion to the average thickness of the first electrode layer calculated excluding the positive electrode substrate (the average thickness of the thickness of the first electrode layer minus the thickness of the positive electrode substrate) may be 0.5 to 2.0, and may be in the same preferred range as the ratio of the average thickness of the electronic insulating member in the stacking direction toward the non-facing portion to the average thickness of the first electrode layer. That is, for example, the ratio of the average thickness of the electronic insulating member in the stacking direction toward the non-facing portion to the average thickness of the positive electrode active material layer (and, in some cases, the positive electrode active material layer and the intermediate layer) may be 0.5 to 2.0, and may be in the same preferred range as the ratio of the average thickness of the electronic insulating member in the stacking direction toward the non-facing portion to the average thickness of the first electrode layer. When the positive electrode substrate of the first electrode layer is laminated on both the positive electrode active material layer and the electronic insulating member, either the ratio of the average thickness of the electronic insulating member in the lamination direction to the non-facing portion of the electronic insulating member to the average thickness of the first electrode layer calculated excluding the positive electrode substrate, or the ratio of the average thickness of the electronic insulating member in the lamination direction to the non-facing portion of the electronic insulating member to the average thickness of the first electrode layer including the positive electrode substrate may be 0.5 or more and 2.0 or less, or may be within a suitable range, or both may be 0.5 or more and 2.0 or less, or within a suitable range. [Example]

[0147] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0148] [Example 1] (Preparation of positive electrode layer) The positive electrode active material was a lithium transition metal composite oxide with an α-NaFeO2 crystal structure containing Ni, Co, and Mn. This positive electrode active material, an argyrodite-type sulfide solid electrolyte, a fibrous carbon material as a conductive agent, a dispersant, a thickener, and a fluorine-based resin as a binder, and a positive electrode mixture paste containing butyl butyrate as a dispersion medium were applied to one side of aluminum foil as a positive electrode substrate and dried. After drying, the resulting mixture was cut into a square shape (2.0 cm x 2.0 cm) in plan view and pressed to obtain a positive electrode layer in which a positive electrode active material layer was laminated on one side of the positive electrode substrate.

[0149] (Production of negative electrode layer) The negative electrode mixture paste, which contained graphite as the negative electrode active material, an argyrodite-type sulfide solid electrolyte, a dispersant, a thickener, and styrene-butadiene rubber (SBR) as a binder, and butyl butyrate as a dispersion medium, was applied to one side of a carbon-coated copper foil as a negative electrode substrate and dried. After drying, the paste was cut into a square shape (2.5 cm × 2.5 cm) in plan view to obtain a negative electrode layer in which a negative electrode active material layer was laminated on one side of the negative electrode substrate.

[0150] (Creating an isolation layer) An isolation layer forming material paste containing an argyrodite-type sulfide solid electrolyte, a dispersant, a thickener, and styrene-butadiene rubber (SBR) as a binder, with butyl butyrate as the dispersion medium, was applied to one side of a resin sheet and dried. After drying, the paste was processed into a square shape (2.5 cm x 2.5 cm) in plan view, resulting in an isolation layer formed on one side of the resin sheet.

[0151] (Preparation of the first laminate) An isolating layer having the same shape as the negative electrode active material layer in plan view was transferred onto the surface of the negative electrode active material layer by pressing, thereby obtaining a first laminate.

[0152] (Preparation of second laminate) The positive electrode layer and the first laminate were superposed so that the positive electrode active material layer and the negative electrode active material layer faced each other via a separator layer. The separator layer had a square-shaped facing portion in plan view where the negative electrode layer and the positive electrode layer faced each other, and a frame-shaped non-facing portion where the negative electrode layer and the positive electrode layer did not face each other.

[0153] A frame-shaped electronic insulating member with outer dimensions of 3.0 cm × 3.0 cm and inner dimensions of 2.0 cm × 2.0 cm was placed on the surface of the separator layer facing the positive electrode layer, which was not facing the separator layer. The electronic insulating member was made of nylon and had a mesh shape with a fiber diameter of 37 μm and a mesh size of 5 μm. The positive electrode layer and the electronic insulating member were then pressed to obtain a second laminate in which the positive electrode layer and the electronic insulating member were bonded to the first laminate. As a result, the configuration of the second laminate was as shown in FIGS. 1 and 2. The pressing conditions for obtaining the second laminate were selected so that the positive electrode mixture layer, the negative electrode mixture layer, and the separator layer were sufficiently densified.

[0154] [Examples 2 to 4, Comparative Examples 1 to 5] The second laminates of Examples 2 to 4 and Comparative Examples 1 to 5 were obtained in the same manner as in Example 1, except that the material, shape, fiber diameter, and mesh size of the electronic insulating member were as shown in Table 1 and the thickness of the electronic insulating member was changed. In Table 1, PVdF stands for polyvinylidene fluoride, PFA stands for perfluoroalkoxyalkane, and Si rubber stands for silicone rubber.

[0155] [evaluation] The electronic insulating member was separated from the second laminate of each example and comparative example, and the Young's modulus and porosity of the separated electronic insulating member were measured. The state of damage to the separator was also visually confirmed from the positive electrode layer side. The cross-section of the second laminate was exposed by ion milling, and the average thicknesses of the electronic insulating member and the positive electrode layer were measured by observing the cross-section with a scanning electron microscope. The ratio of the average thickness of the electronic insulating member to the average thickness of the positive electrode layer (the ratio of the average thickness of the electronic insulating member to the average thickness of the positive electrode layer) was calculated from the average thickness of the electronic insulating member. The results are shown in Table 1. The criteria for determining the state of damage to the separator in Table 1 were as follows: if the negative electrode layer was exposed due to cracks or peeling of the separator layer when visually observed from the positive electrode layer side, the state of damage was rated as "B"; if the negative electrode layer was not exposed, the state of damage was rated as "A."

[0156] [Table 1]

[0157] As shown in Table 1, in the second laminates of Examples 1 to 4 in which the ratio of the average thickness of the electronic insulating member to the average thickness of the positive electrode layer was 0.5 or more and 2.0 or less and the Young's modulus of the electronic insulating member was 0.002 MPa or more and 0.03 MPa or less, damage to the isolation layer was suppressed.

[0158] The present invention can be applied to all-solid-state energy storage devices used as power sources for electronic devices such as personal computers and communication terminals, automobiles, and the like. [Explanation of symbols]

[0159] 1, 2 All-solid-state storage element 10, 102 First electrode layer (positive electrode layer) 11, 112 Positive electrode substrate 12, 122 Cathode active material layer 122a side 13 Side 20 isolation layer 21 Opposing part 22 Non-opposing part 30 Second electrode layer (negative electrode layer) 31 Negative electrode substrate 32 Negative electrode active material layer 40, 402 Electronic insulating materials 50 Energy Storage Unit 60 Electricity storage device

Claims

1. a first electrode layer, an isolation layer stacked on the first electrode layer, and a second electrode layer stacked on the isolation layer; an area of ​​the first electrode layer is smaller than an area of ​​the isolation layer and an area of ​​the second electrode layer; the isolation layer has an opposing portion on which a portion of the second electrode layer opposing the first electrode layer is laminated, and a non-opposing portion on which a portion of the second electrode layer not opposing the first electrode layer is laminated, an electronic insulating member laminated on a surface of the non-opposing portion on the first electrode layer side; a ratio of an average thickness of the electronic insulating member in a stacking direction to the non-facing portion to an average thickness of the first electrode layer is 0.5 or more and 2.0 or less; An all-solid-state energy storage element, wherein the Young's modulus of the electronic insulating member is 0.002 MPa or more and 0.03 MPa or less.

2. The all-solid-state energy storage element according to claim 1 , wherein the first electrode layer is a positive electrode layer, and the second electrode layer is a negative electrode layer.

3. The all-solid-state energy storage element according to claim 1 or 2, wherein the electronic insulating member is a porous body.

4. The all-solid-state energy storage element according to claim 3 , wherein the electronic insulating member is in a mesh form.

5. The all-solid-state energy storage element according to claim 3 , wherein the porosity of the electronic insulating member is 30% or more and 80% or less.

6. The all-solid-state energy storage element according to claim 1 or 2, wherein the electronic insulating member comprises polyamide or fluororesin.

7. 3 . The all-solid-state energy storage element according to claim 1 , wherein the electronic insulating member is configured in a frame shape so as to surround the periphery of the first electrode layer when viewed in the stacking direction to the non-facing portion. 4 .

Images