JP7765295B2 - all solid state battery - Google Patents

Description

The present invention relates to an all-solid-state battery.

Patent Document 1 discloses an all-solid-state battery configured to prevent short-circuiting between the positive electrode layer and the negative electrode layer. Specifically, the solid electrolyte layer has an insulator on its outer periphery, and the insulator has a frame shape with a hollow center or frame portion. At least a portion of the inner periphery of the frame has a void portion, and at least a portion of the void portion is filled with a solid electrolyte. The thickness of the center portion of the solid electrolyte layer is the same as or greater than the thickness of the void portion filled with the solid electrolyte.

Patent No. 6090074

However, in the case of an all-solid-state battery using a deposition-type negative electrode, the configuration described in the above document may result in the deposited metal undergoing plastic deformation and moving outward from the edge of the electrode, potentially preventing the migrated deposited metal from contributing to charge and discharge. This inability to contribute to charge and discharge reduces the so-called cycle durability. This problem becomes particularly pronounced when the capacity of the positive electrode is increased to improve the battery's energy density.

The present invention aims to provide an all-solid-state battery with high energy density while preventing short-circuiting between the positive electrode layer and the negative electrode layer.

One aspect of the present invention provides an all-solid-state battery in which a positive electrode and a negative electrode are stacked with a solid electrolyte layer interposed between them. In this all-solid-state battery, the negative electrode has a negative electrode current collector foil and a pair of negative electrode protective layers stacked with the negative electrode current collector foil sandwiched between them. The negative electrode has an end face that protrudes outward from the end face of the solid electrolyte layer. At least a portion of the region of the negative electrode protective layer facing the solid electrolyte layer is ion conductive, and at least a region including the end face is adhered to the negative electrode current collector foil via an adhesive layer outside the end face of the solid electrolyte layer. Furthermore, the amount of change in the distance in the stacking direction from the surface of the region of the negative electrode protective layer adhered to the negative electrode current collector foil to the contact surface with the solid electrolyte layer during charging and discharging is greater than the amount of change in the dimension of the adhesive layer during charging and discharging.

The above aspect makes it possible to provide an all-solid-state battery with high energy density while preventing short circuits between the positive electrode layer and the negative electrode layer.

FIG. 1 is a diagram showing a portion of a cross section of a known all-solid-state battery in a fully discharged state. FIG. 2 is a diagram showing a cross section of a portion of a known all-solid-state battery in a charged state. FIG. 3 is a diagram showing a part of a cross section of an all-solid-state battery in a fully discharged state according to an embodiment of the present invention. FIG. 4 is a diagram showing a part of a cross section of an all-solid-state battery in a charged state according to an embodiment of the present invention. FIG. 5 is a diagram showing variations in adhesive layers depending on energy density. FIG. 6 is a diagram showing a part of a cross section of an all-solid-state battery according to a modified example of the first embodiment in a fully discharged state. FIG. 7 is a diagram showing a part of a cross section of the all-solid-state battery according to the second embodiment in a fully discharged state. FIG. 8 is a diagram showing a part of a cross section of an all-solid-state battery according to a modified example of the second embodiment in a fully discharged state. FIG. 9 is a diagram showing a part of a cross section of the all-solid-state battery according to the third embodiment in a fully discharged state. FIG. 10 is a diagram showing a part of a cross section of an all-solid-state battery according to a first modified example of the third embodiment in a fully discharged state. FIG. 11 is a diagram showing a part of a cross section of an all-solid-state battery according to a second modification of the third embodiment in a fully discharged state. FIG. 12 is a diagram showing a part of a cross section of an all-solid-state battery according to a third modification of the third embodiment in a fully discharged state. FIG. 13 is a diagram showing the manufacturing process of an all-solid-state battery.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, the problems with all-solid-state batteries that use a deposition-type negative electrode will be explained with reference to Figures 1 and 2. Figures 1 and 2 are partial cross-sectional views of a known all-solid-state battery, with Figure 1 showing the fully discharged state and Figure 2 showing the state in which metal has been deposited on the negative electrode due to charging.

Charging from the fully discharged state shown in Figure 1 causes metal to deposit between the negative electrode current collector foil and the solid electrolyte layer. Because a confining pressure is applied to the all-solid-state battery from both sides in the stacking direction, the deposited metal (hereinafter also referred to as "deposited metal") undergoes plastic deformation and moves in a direction perpendicular to the stacking direction. Increasing the positive electrode capacity to improve energy density also increases the amount of deposited metal, which may protrude from the edges of the all-solid-state battery, as shown in Figure 2. By having the edges of the solid electrolyte layer protrude beyond the edges of the positive electrode layer and negative electrode current collector foil as shown in Figure 1, short circuits caused by the deposited metal bypassing the solid electrolyte layer at the edges of the all-solid-state battery and reaching the positive electrode layer can be prevented. However, because the protruding deposited metal does not contribute to charge and discharge, the greater the amount of protruding deposited metal, the lower the cycle durability. In other words, to improve the energy density of all-solid-state batteries, the problem of reduced cycle durability due to the protruding deposited metal must be resolved. A configuration for preventing short circuits caused by deposited metal and improving energy density is described below.

[First embodiment]
3 and 4 are views showing a part of a cross section of the all-solid-state battery 1 according to this embodiment, with Fig. 3 showing a fully discharged state and Fig. 4 showing a state in which metal has been deposited on the negative electrode due to charging. In the following description, the vertical direction in the drawing is referred to as the stacking direction, and the horizontal direction in the drawing is referred to as the width direction.

The all-solid-state battery 1 is composed of multiple stacked unit cells, each of which has a positive electrode 3 and a negative electrode 4 stacked with a solid electrolyte layer 2 interposed between them. A confining pressure is applied to the all-solid-state battery 1 from both sides in the stacking direction to maintain good contact between the layers.

The positive electrode 3 comprises a positive electrode current collector foil 5 and a positive electrode layer 6 formed on both sides of the positive electrode current collector foil 5. The positive electrode current collector foil 5 is formed from a material known for forming such materials. The same applies to the positive electrode layer 6.

The negative electrode 4 comprises a negative electrode current collector foil 7 and a negative electrode protective layer 8 disposed on both sides of the negative electrode current collector foil 7. The negative electrode current collector foil 7 is formed from a material known for such purposes.

The end faces of the negative electrode 4 (negative electrode current collector end face 7A and negative electrode protective layer end face 8A) protrude outward beyond the solid electrolyte layer end face 2A. In this embodiment, "protruding outward" means protruding in a direction away from the solid electrolyte layer end face 2A in the width direction.

At least a portion of the region of the anode protective layer 8 facing the solid electrolyte layer 2 is ion conductive, and at least a region including the end face 8A is adhered to the anode current collector foil 7 outside the end face 2A of the solid electrolyte layer via an adhesive layer 9. The adhesive layer 9 is formed from a known adhesive. Note that the entire anode protective layer 8 in this embodiment is formed from a material that is ion conductive.

The anode protective layer 8 also contains at least one of a carbon material (e.g., carbon black) and a solid electrolyte (e.g., a sulfide-based solid electrolyte such as LGPS or LPS) as a material for providing ion conductivity. The anode protective layer 8 may be produced by impregnating a porous resin sheet or porous metal sheet with the carbon material and solid electrolyte, or by coating the inside of a frame-shaped resin sheet or metal sheet with a mixture of the carbon material and solid electrolyte and a binder such as resin. The thickness of the anode protective layer 8 in this embodiment is 1 to 100 μm (more preferably 1 to 10 μm).

When charging is performed from the fully discharged state shown in Figure 3, metal precipitates between the negative electrode current collector foil 7 and the negative electrode protective layer 8 as shown in Figure 4 (hereinafter, the precipitated metal will also be referred to as metal precipitate 10), and the distance in the stacking direction between the negative electrode current collector foil 7 and the negative electrode protective layer 8 increases in the precipitated area. However, the ends of the negative electrode current collector foil 7 and the negative electrode protective layer 8 are bonded by an adhesive layer 9, so even if the amount of metal precipitate 10 increases, it will not protrude beyond the solid electrolyte layer end surface 2A as shown in Figure 2 above. In other words, the adhesive layer 9 blocks the movement of the metal precipitate 10 in the width direction.

As the metal deposits, the dimension of the adhesive layer 9 in the stacking direction also changes depending on the elasticity of the adhesive used. However, this change (B1-B0 in the figure) is smaller than the change in the distance in the stacking direction from the surface 8B of the area of the negative electrode protective layer 8 that is bonded to the negative electrode current collector foil 7 to the contact surface 8C with the solid electrolyte layer 2 (A1-A0 in the figure). In other words, the relationship A1-A0 > B1-B0 holds.

The above relationship means that while the amount of deposited metal 10 is relatively small, the anode protective layer 8 only deforms, and the dimension of the adhesive layer 9 in the stacking direction changes very little; thereafter, the dimension of the adhesive layer 9 in the stacking direction also increases as it is pulled in the stacking direction by the deformed anode protective layer 8.

In contrast, when A1 - A0 < B1 - B0, the anode protective layer 8 begins to push up the adhesive layer 9 even when the amount of deposited metal 10 is relatively small. In other words, the adhesive layer 9 experiences a force in the peeling direction every time the battery is charged, which can easily reduce the sealing ability of the adhesive layer 9 and potentially impair its ability to block the movement of the deposited metal 10 in the width direction.

To further improve energy density, it is desirable for the anode protective layer 8 to have a wide deformable area. Therefore, it is desirable for the width dimension of the adhesive layer 9 to be as narrow as possible (for example, 10 mm or less, more preferably 3 mm or less) within the range that ensures adhesive strength sufficient to maintain dimensional changes that satisfy the relationship A1-A0 > B1-B0.

Furthermore, in order to ensure a deformable area of the anode protective layer 8 corresponding to the amount of deposited metal 10, the distance C0 between the solid electrolyte layer end surface 2A and the adhesive layer 9 is desirably at least equal to or greater than the dimension in the stacking direction of the deposited metal 10 when fully charged. By ensuring a deformable area of the anode protective layer 8 in this way, it is possible to prevent stress from being applied to the solid electrolyte layer 2 and shear force from being applied to the anode protective layer 8 during charging and discharging.

Figure 5 shows variations of the adhesive layer 9 to accommodate larger positive electrode capacities. Note that although the reference numerals for each part have been omitted, they are the same as those in Figures 3 and 4.

The larger the positive electrode capacity, the greater the change in the dimension of the deposited metal 10 in the stacking direction. Therefore, to increase the positive electrode capacity, it is necessary to increase the deformable area of the negative electrode protective layer 8. Therefore, the width direction dimension of the adhesive layer 9 is set according to the required size of the deformable area of the negative electrode protective layer 8 (Figure 5 (A)).

In the case of Figure 5(B), where the change in the dimension of the deposited metal 10 in the stacking direction is greater than in Figure 5(A), the deformable area of the anode protective layer 8 needs to be larger than in the case of Figure 5(A). Therefore, by making the width direction dimension of the adhesive layer 9 smaller than in the case of Figure 5(A), the deformable area of the anode protective layer 8 is secured.

In addition, to ensure a deformable area for the anode protective layer 8, the dimension of the adhesive layer 9 in the stacking direction may be increased, as in the case of Figure 5(C). Note that in the left image of Figure 5(C), the side of the adhesive layer 9 is not bonded to the anode protective layer 8.

By using the above-described method to ensure a deformable area in the anode protective layer 8, the positive electrode capacity can be increased, and as a result, the energy density can be increased. Note that (A) to (C) in Figure 5 show examples of variations in the adhesive layer 9 to accommodate larger positive electrode capacities, and the configurations for ensuring a deformable area in the anode protective layer 8 are not limited to these.

Figure 6 is a diagram showing a portion of a cross section of an all-solid-state battery 1 according to a modified example of this embodiment in a fully discharged state. This modified example, like the above-described embodiment, also falls within the scope of the present invention.

The difference between this modification and the above embodiment is that the anode protective layer 8 in this modification includes an insulating portion 11 that is insulated on the surface of the solid electrolyte layer 2 side in a region that protrudes outward from the end face 6A of the cathode layer 6. The insulating portion 11 is formed, for example, from a resin, a metal oxide, or a mixture thereof.

By providing the insulating portion 11 in this manner, it is possible to prevent short-circuiting between the negative electrode protective layer 8 and the positive electrode layer 6 and positive electrode current collecting foil 5, even when the negative electrode 4 experiences large changes in dimension in the stacking direction due to charging and discharging, as shown in Figure 5(C), for example.

As described above, in this embodiment, in an all-solid-state battery 1 in which a positive electrode 3 and a negative electrode 4 are stacked with a solid electrolyte layer 2 interposed therebetween, the negative electrode 4 has a negative electrode current collector foil 7 and a pair of negative electrode protective layers 8 stacked on either side of the negative electrode current collector foil 7, and the end face of the negative electrode 4 protrudes outward from the end face 2A of the solid electrolyte layer 2. At least a portion of the region of the negative electrode protective layer 8 facing the solid electrolyte layer 2 is ion conductive, and a region including at least the end face is bonded to the negative electrode current collector foil 7 via an adhesive layer 9 outside the end face of the solid electrolyte layer 2. By bonding the vicinity of the end in this manner, deformation of the deposited metal 10, for example, as shown in FIG. 2, can be suppressed. Furthermore, because the end of the negative electrode 4 is located outside the end of the solid electrolyte layer 2, a decrease in charge/discharge capacity and the generation of shear stress in the solid electrolyte layer 2 during discharge can be prevented.

In addition, the change in the distance in the stacking direction from the surface of the area of the negative electrode protective layer 8 bonded to the negative electrode current collector foil 7 to the contact surface with the solid electrolyte layer 2 (A1-A0) that occurs during charging and discharging is greater than the change in the dimension of the adhesive layer 9 in the stacking direction (B1-B0) that occurs during charging and discharging. This makes it easier to maintain the sealing function by preventing tearing or peeling of the adhesive portion, and ultimately improves the energy density of the all-solid-state battery 1.

In this embodiment, the anode protective layer 8 includes an insulating portion 11 that is insulated on the surface of the solid electrolyte layer 2 side in the region that protrudes outward from the end face 3A of the positive electrode 3. This improves the electronic insulation of the region of the anode protective layer 8 that protrudes outward from the end face 3A of the positive electrode 3, and prevents a short circuit between the anode protective layer 8 and the positive electrode layer 6 or the positive electrode current collector foil 5 due to deformation of the deposited metal 10, even if the thickness of the anode 4 changes significantly during charging and discharging.

In this embodiment, the anode protective layer 8 contains at least one of a carbon material and a solid electrolyte as an ion-conductive material. This ensures ion conductivity while preventing metal deposited between the anode protective layer 8 and the anode current collector foil 7 from penetrating and reaching the solid electrolyte layer 2.

In this embodiment, the anode protective layer 8 contains a solid electrolyte as an ion-conductive material. This makes it possible to suppress an increase in the internal resistance of the all-solid-state battery 1.

[Second embodiment]
Fig. 7 is a diagram showing a portion of a cross section of the all-solid-state battery 1 according to this embodiment in a fully discharged state. The difference from Fig. 3 is the anode protective layer 8. The anode protective layer 8 of this embodiment is composed of an ion-conductive material-free region 13 extending from the end face 8A to the inside of the solid electrolyte layer end face 2A, and an ion-conductive material-containing region 12 located further inside.

The ion-conductive material-free region 13 is composed of a resin sheet that is electronically insulating and has a higher air permeability than the ion-conductive material-containing region 12. Examples of suitable materials include polypropylene, polyethylene terephthalate, polyethylene naphthalate, and polyacrylonitrile. Using a resin sheet ensures flexibility in the region that deforms during charging and discharging. In other words, it increases the strength against repeated deformation during charging and discharging. Furthermore, the relatively high air permeability of the region used for adhesion further improves the sealing ability against the deposited metal 10.

As mentioned above, the air permeability of the ion-conductive material-free region 13 should be greater than that of the ion-conductive material-containing region 12. However, the air permeability measured using the Gurley tester method standardized by JIS is preferably 1000 seconds/100 ml or more, and more preferably 5000 seconds/100 ml or more.

By providing the ion-conductive material-free region 13, as in the modified example described above, it is possible to prevent short circuits between the negative electrode protective layer 8 and the positive electrode layer 6 and the positive electrode current collector foil 5, and also to improve strength.

The smaller the ion-conductive material-containing region 12, the smaller the area of the anode protective layer 8 available for battery reaction. Therefore, the widthwise dimension D of the portion of the ion-conductive material-free region 13 inside the solid electrolyte layer end surface 2A is preferably such that the area available for battery reaction does not become excessively narrow. The specific value varies depending on the size of the all-solid-state battery 1, but for sizes generally expected for vehicle batteries, it is preferably within 2 mm, and more preferably within 1 mm.

Figure 8 shows a partial cross section of an all-solid-state battery 1 in a fully discharged state according to a modified example of this embodiment. This modified example, like the above-described embodiment, also falls within the scope of the present invention.

The difference from Figure 7 is that at least a portion of the ion-conductive material-free region 13, in this case the portion inside the solid electrolyte layer end surface 2A, is adhered to the solid electrolyte layer 2 via an adhesive layer 14.

As a result, even if metal precipitates between the solid electrolyte layer 2 and the anode protective layer 8, the adhesive layer 14 acts as a seal, preventing the precipitated metal 10 from spilling out beyond the solid electrolyte layer end surface 2A.

As described above, in this embodiment, the anode protective layer 8 comprises an ion-conductive material-free region 13 extending from the end face to the inside of the end face 2A of the solid electrolyte layer, and an ion-conductive material-containing region 12 located inside the ion-conductive material-free region 13. This improves the electronic insulation and strength of the region of the anode protective layer 8 that protrudes outward from the end face 3A of the positive electrode 3, and prevents a short circuit between the anode protective layer 8 and the positive electrode layer 6 or positive electrode current collector foil 5 due to deformation of the deposited metal 10, even if the thickness of the anode 4 changes significantly during charging and discharging.

In this embodiment, at least a portion of the ion-conductive material-free region 13 of the anode protective layer 8 is adhered to the solid electrolyte layer 2 via the adhesive layer 14. This improves the sealing ability against metal deposited between the anode protective layer 8 and the solid electrolyte layer 2.

In this embodiment, the ion-conductive material-free region 13 of the anode protective layer 8 is made of a resin sheet that is electronically insulating and has a higher air permeability than the ion-conductive material-containing region 12. This allows for improved sealing performance while maintaining the flexibility of the ion-conductive material-free region 13.

[Third embodiment]
9 is a diagram showing a part of a cross section of the all-solid-state battery 1 according to this embodiment in a fully discharged state. The difference from FIG. 3 is that the end face 3A of the positive electrode 3 is located more inward in the width direction than the end 2A of the contact portion between the anode protective layer 8 and the solid electrolyte layer 2.

With this configuration, when the anode protective layer 8 deforms due to changes in the thickness of the anode 4, it becomes less likely that a short circuit will occur due to contact between the anode protective layer 8 and the cathode 3 bypassing the solid electrolyte layer 2.

Figure 10 is a diagram showing a portion of a cross section of an all-solid-state battery 1 according to a first modification of this embodiment in a fully discharged state. This modification, like the above-described embodiment, also falls within the scope of the present invention.

The differences from Figure 9 are that the end face 5A of the positive electrode current collector foil 5 is located at approximately the same position in the width direction as the end face 2A of the solid electrolyte layer, and that a support portion 15 is located in the gap between the solid electrolyte layer 2 and the positive electrode current collector foil 5, outside the end face 6A of the positive electrode layer 6. The support portion 15 is formed by applying and drying a resin or insulating slurry, etc.

As shown in Figure 9, if the end face 3A of the positive electrode 3 is located inside the end 2A of the contact area between the anode protective layer 8 and the solid electrolyte layer 2, and the area outside the end face 3A of the positive electrode 3 is hollow, when the thickness of the anode 4 increases due to metal deposition, bending stress is generated in the solid electrolyte layer 2 with the end of the positive electrode layer 6 as a fulcrum. Therefore, repeated charge and discharge causes the solid electrolyte layer 2 to bend repeatedly, and in the case of an all-solid-state battery 1 with a large amount of deposited metal 10, cracks may occur in the solid electrolyte layer 2.

In this regard, if the configuration includes a support portion 15 as in this modified example, bending deformation of the solid electrolyte layer 2 can be suppressed, thereby suppressing the occurrence of cracks.

Figure 11 is a diagram showing a portion of a cross section of an all-solid-state battery 1 according to a second modification of this embodiment in a fully discharged state. This modification, like the above-described embodiment, also falls within the scope of the present invention.

The difference from Figure 10 is that the support portion 15 is formed as part of the solid electrolyte layer 2. The configuration of this modified example also achieves the same effects as the first modified example.

Figure 12 is a diagram showing a portion of a cross section of an all-solid-state battery 1 according to a third modification of this embodiment in a fully discharged state. This modification, like the above-described embodiment, also falls within the scope of the present invention.

The difference from Figure 10 is that the distance E2 from the end of the contact portion between the anode protection layer 8 and the solid electrolyte layer 2 to the end face of the cathode layer 6 is smaller than the distance E1 in Figure 10, i.e., the cathode layer 6 is wider in the width direction, and therefore the support portion 15 protrudes outward in the width direction. The configuration of this modified example provides the same effects as the first modified example, as well as the effect of being able to increase the area of the cathode layer 6 (i.e., increase the cathode capacity).

As described above, in this embodiment, the end face 3A of the positive electrode 3 is located inside the end 2A of the contact portion between the negative electrode protective layer 8 and the solid electrolyte layer 2. This further reduces the occurrence of a short circuit between the negative electrode protective layer 8 and the positive electrode 3.

In this embodiment, the support portion 15 is formed as part of the solid electrolyte layer 2 or as a separate member from the solid electrolyte layer 2, and is positioned outside the end surface 3A of the positive electrode 3. This makes it possible to suppress the occurrence of cracks in the solid electrolyte layer 2 due to changes in the thickness of the negative electrode 4 during charging and discharging.

[Manufacturing method]
Next, a method for manufacturing the all-solid-state battery 1 will be described with reference to FIG.

Here, we will explain the manufacturing method of the all-solid-state battery 1 shown in Figure 3 and explained in the first embodiment. All-solid-state batteries 1 according to other embodiments, etc., are basically manufactured using the same method, although there are differences such as the provision of an insulating section 11 (Figure 6), the provision of an ion-conductive material-free region 13 (Figure 7), the provision of an adhesive layer 14 (Figure 8), different width dimensions of the positive electrode 3 (Figure 9), and the provision of a support section 15.

The all-solid-state battery 1 is made by stacking unit cells, each having a positive electrode 3 formed on one side of a solid electrolyte layer 2 and a negative electrode 4 formed on the other side. However, during manufacturing, a process is used in which the positive electrode-solid electrolyte assembly 16, which is the assembly of the positive electrode 3 and solid electrolyte layer 2, and the negative electrode assembly 17, which is the assembly of the negative electrode current collector foil 7 and the negative electrode protective layer 8, are separately produced and then the two assemblies are stacked together.

First, the process for producing the positive electrode-solid electrolyte assembly 16 will be described with reference to steps (A1) to (A3) in Figure 12.

In step (A1), a positive electrode layer 6 is formed on both sides of a positive electrode current collector foil 5 by coating or other methods. In the subsequent step (A2), a solid electrolyte layer 2 is formed on the positive electrode layer 6 formed in step (A1) by coating, transfer, or other methods. This results in the production of a positive electrode-solid electrolyte assembly 16 shown in step (A3).

Next, the process for producing the negative electrode assembly 17 will be described with reference to steps (B1) to (B3) in Figure 12.

In step (B1), adhesive layers 9 are formed near the edges of both sides of the negative electrode current collector foil 7 by coating or other methods. In the subsequent step (B2), negative electrode protective layers 8 formed by coating or other methods are placed on both sides of the negative electrode current collector foil 7. At this time, the edges of the negative electrode protective layers 8 are adhered to the negative electrode current collector foil 7 via the adhesive layers 9. This produces the negative electrode assembly 17 shown in step (B3).

Then, in step (C), the positive electrode-solid electrolyte assembly 16 and the negative electrode assembly 17 are laminated by a method such as press lamination.

There are various options for solvents to use during coating, depending on the material being coated and the material being coated. However, when using a manufacturing method in which a positive electrode 3 is formed on one side of a solid electrolyte layer 2 and a negative electrode 4 is formed on the other side in a single process, the solvents that can be used in each coating process are limited to those that do not interfere with other coating processes.

In contrast, by using a manufacturing method such as the present invention in which the positive electrode-solid electrolyte assembly 16 and the negative electrode assembly 17 are separately manufactured and then laminated by a method such as press lamination, a solvent suitable for manufacturing the positive electrode-solid electrolyte assembly 16 and a solvent suitable for the negative electrode assembly 17 can be selected separately. In other words, the number of solvent options increases.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical concept described in the claims.

1 All solid battery, 2 Solid electrolyte layer, 3 Positive electrode, 4 Negative electrode, 5 Positive electrode current collector foil, 6 Positive electrode layer, 7 Negative electrode current collector foil, 8 Negative electrode protective layer, 9 Adhesive part, 10 Deposited metal, 15 Support part

Claims (9)

In an all-solid-state battery in which a positive electrode and a negative electrode are stacked with a solid electrolyte layer interposed therebetween,
the negative electrode includes a negative electrode current collector foil and a pair of negative electrode protective layers laminated with the negative electrode current collector foil sandwiched therebetween,
an end face of the negative electrode protrudes outward beyond an end face of the solid electrolyte layer;
at least a part of a region of the anode protective layer facing the solid electrolyte layer has ion conductivity, and a region including at least an end surface of the anode protective layer is bonded to the anode current collector foil via an adhesive layer outside the end surface of the solid electrolyte layer;
a change in a distance in a stacking direction from a surface of a region of the negative electrode protective layer that is bonded to the negative electrode current collecting foil to a contact surface with the solid electrolyte layer, which change with charge and discharge, is larger than a change in a dimension of the adhesive layer in the stacking direction, which change with charge and discharge. The all-solid-state battery according to claim 1,
the anode protective layer has an insulating portion that is insulated on a surface of the anode protective layer facing the solid electrolyte layer in a region that protrudes outward from the end face of the positive electrode. The all-solid-state battery according to claim 1 or 2,
the anode protective layer comprises an ion-conductive material-free region extending from an end surface to an inner portion of the end surface of the solid electrolyte layer, and an ion-conductive material-containing region extending inward from the ion-conductive material-free region. The all-solid-state battery according to claim 3,
the negative electrode protective layer is such that at least a portion of the ion-conductive material-free region is adhered to the solid electrolyte layer via the adhesive layer. The all-solid-state battery according to any one of claims 1 to 4,
an end face of the positive electrode is located inside an end of a contact portion between the negative electrode protection layer and the solid electrolyte layer. The all-solid-state battery according to claim 5,
a support portion formed of a part of the solid electrolyte layer or a separate material from the solid electrolyte layer, and disposed outside an end face of the positive electrode. The all-solid-state battery according to any one of claims 1 to 6,
the anode protective layer contains a carbon material as the ion-conductive material. The all-solid-state battery according to any one of claims 1 to 7,
the anode protective layer contains a solid electrolyte as the ion-conductive material. The all-solid-state battery according to any one of claims 1 to 8,
the region without ion conductivity of the negative electrode protective layer is formed of a resin sheet that has electronic insulation and a higher air permeability than the region with ion conductivity.