JP2024025571A - All-solid battery and method for applying pressure to all-solid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique during pressure application that can apply a sufficient pressure even to ends of an all-solid battery.

SOLUTION: An all-solid battery 1 comprises: a power generation element 2; frame-like first insulating parts 3 that are arranged to surround outer peripheral ends of the power generation element 2 and formed of an elastic body; a pressure application mechanism 5 that applies a pressure so as to compress the power generation element 2 and the first insulating parts 3 along a lamination direction; and frame-like second insulating parts 4 that are arranged to surround the outer peripheral ends of the first insulating parts 3.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to an all-solid-state battery and a method for pressurizing an all-solid-state battery.

All-solid-state batteries are secondary batteries made of solid materials. All-solid-state batteries usually have a solid electrolyte layer, a positive electrode layer, and a negative electrode layer as power generating elements. These are stacked such that the solid electrolyte layer is sandwiched between the positive electrode layer and the negative electrode layer.

In order for an all-solid-state battery to fully exhibit its functions, each electrode layer must be firmly bonded to the solid electrolyte layer. For this reason, all-solid-state batteries are compressed along the stacking direction, for example, during manufacture or use.

A technique related to pressurization during manufacturing is described in, for example, Patent Document 1. Patent Document 1 discloses that when a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated and press-molded, a short circuit may occur between the positive electrode layer and the negative electrode layer, which may impair the characteristics of the electric element. Are listed. And, as an invention that suppresses short circuits, it includes an element portion configured by laminating a first solid electrode layer, a solid electrolyte layer having lithium ion conductivity, and a second solid electrode layer in this order, An electric element in which the outline of at least one of the first solid electrode layer and the second solid electrode layer falls within the outline of the solid electrolyte layer when the element part is viewed in plan. is disclosed.

Japanese Patent Application Publication No. 2015-76178

By the way, the present inventors have discovered that even if the all-solid-state battery is pressurized along the stacking direction, pressure is difficult to be applied to the ends of the all-solid-state battery. In order to fully demonstrate the functions of an all-solid-state battery, it is desirable to apply sufficient pressure even at the ends.

Therefore, an object of the present invention is to provide a technique that can apply sufficient pressure to the end portion of an all-solid-state battery during pressurization.

In one aspect, the all-solid-state battery according to the present invention includes a solid electrolyte layer, a first electrode layer laminated on one surface of the solid electrolyte layer, and a second electrode layer laminated on the other surface of the solid electrolyte layer. a power generation element having an electrode layer; a frame-shaped first insulating section formed of an elastic body and arranged so as to surround the outer peripheral end of the power generation element; It includes a pressurizing mechanism that applies pressure so as to compress it, and a frame-shaped second insulating part that is arranged so as to surround the outer peripheral end of the first insulating part. The Young's modulus of the second insulating portion is greater than the Young's modulus of the first insulating portion. In the state of being pressurized by the pressurizing mechanism, the outer circumferential end of the first insulating part contacts the second insulating part, and the outer circumferential end of the power generation element is pressurized by the first insulating part.

According to the present invention, a technique is provided that allows sufficient pressure to be applied to the end portion of an all-solid-state battery during pressurization.

FIG. 1 is a diagram schematically showing main parts of an all-solid-state battery according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the overall configuration of the all-solid-state battery according to the first embodiment. FIG. 3 is a schematic cross-sectional view showing a part of the end of the all-solid-state battery according to the first embodiment. FIG. 4A is a cross-sectional view schematically showing an all-solid-state battery according to a reference example. FIG. 4B is a schematic diagram showing how pressure is applied in the all-solid-state battery according to the first embodiment. FIG. 5 is a diagram showing an example of the arrangement of the first insulating part and the second insulating part. FIG. 6 is a diagram showing another example of the arrangement of the first insulating part and the second insulating part. FIG. 7 is a diagram showing still another example of the arrangement of the first insulating part and the second insulating part. FIG. 8 is a diagram showing still another example of the arrangement of the first insulating part and the second insulating part. FIG. 9 is a cross-sectional view schematically showing the configuration of an all-solid-state battery according to the second embodiment. FIG. 10 is a cross-sectional view schematically showing the configuration of an all-solid-state battery according to the third embodiment. FIG. 11 is a cross-sectional view schematically showing the configuration of an all-solid-state battery according to the fourth embodiment. FIG. 12 is a cross-sectional view schematically showing the configuration of an all-solid-state battery according to the fifth embodiment. FIG. 13 is a cross-sectional view schematically showing the configuration of an all-solid-state battery according to the sixth embodiment. FIG. 14 is a cross-sectional view schematically showing the configuration of an all-solid-state battery according to the seventh embodiment. FIG. 15 is a cross-sectional view schematically showing the configuration of an all-solid-state battery according to the eighth embodiment.

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

First, the principle of the all-solid-state battery 1 according to the embodiment of the present invention will be explained. FIG. 1 is a diagram schematically showing the main parts of an all-solid-state battery 1 according to this embodiment, and is a diagram for explaining the principle of this embodiment.

As shown in FIG. 1, the all-solid-state battery 1 includes a power generation element 2, a pressurizing mechanism 5, a first insulating section 3, and a second insulating section 4. Although not shown in FIG. 1, the power generation element 2 has a structure in which a first electrode layer, a solid electrolyte layer, and a second electrode layer are stacked in this order along the stacking direction. The first insulating section 3 has a frame shape and is arranged so as to surround the outer peripheral end surface of the power generating element 2. The second insulating part 4 also has a frame shape and is arranged so as to surround the outer peripheral end surface of the first insulating part 3. The Young's modulus of the second insulating section 4 is larger than that of the first insulating section 3. The pressure mechanism 5 is configured to press the power generation element 2 and the first insulating section 3 along the stacking direction.

According to the above-described configuration, the power generating element 2 and the first insulating section 3 are pressurized by the pressurizing mechanism 5 along the stacking direction. Here, since the first insulating part 3 is made of an elastic body, it is compressed by pressurization. A force is generated in the compressed first insulating portion 3 that causes it to expand in the lateral direction (direction perpendicular to the stacking direction). The compressed outer peripheral end of the first insulating part 3 is in contact with the inner peripheral end of the second insulating part 4. Since the Young's modulus of the second insulating portion 4 is smaller than that of the first insulating portion 3, the first insulating portion 3 hardly expands outward. As a result, the force generated in the compressed first insulating portion 3 is mainly directed inward. As a result, the end of the power generating element 2 is pressurized by the first insulating section 3. Therefore, sufficient pressure can be applied even to the ends of the all-solid-state battery 1 to which pressure is difficult to apply.

The above is an explanation of the principle of this embodiment. Next, the all-solid-state battery 1 according to this embodiment will be specifically explained.

(First embodiment)
FIG. 2 is a schematic diagram showing the overall configuration of the all-solid-state battery 1 according to the first embodiment. As shown in FIG. 2, this all-solid-state battery 1 includes a battery cell 8, a pair of pressure plates 6, and a pair of elastic sheets 7. The battery cell 8 is generally sheet-shaped. A pair of elastic sheets 7 are provided so as to sandwich the battery cells 8 in the stacking direction. The pair of pressure plates 6 are provided outside the pair of elastic sheets 7. The pair of pressure plates 6 are bound together by, for example, a rubber band. As a result, a compressive force is applied to the battery cells 8 from the pair of pressure plates 6 via the pair of elastic sheets 7 in the stacking direction. That is, the pair of pressure plates 6 and the pair of elastic sheets 7 function as the pressure mechanism 5.

FIG. 3 is a schematic cross-sectional view showing a part of the end portion of the all-solid-state battery 1. As shown in FIG. FIG. 3 shows the internal configuration of the battery cell 8, etc. As shown in FIG. 3, the battery cell 8 includes an exterior material 9, a plurality of power generation elements 2, a plurality of first current collectors 10, a plurality of second current collectors 11, a plurality of first insulating parts 3, and It has a plurality of second insulating parts 4.

(exterior material)
Exterior material 9 is provided to protect the components present within battery cell 8 . That is, the plurality of power generation elements 2, the plurality of first current collectors 10, the plurality of second current collectors 11, the plurality of first insulating parts 3, and the plurality of second insulating parts 4 are inside the exterior material 9. It is accommodated. The exterior material 9 is made of, for example, an aluminum film or the like.

(current collector)
The plurality of first current collectors 10 and the plurality of second current collectors 11 are provided to electrically connect the plurality of power generation elements 2 to an external device. One of the first current collector 10 and the second current collector 11 is a positive electrode current collector, and the other is a negative electrode current collector. The first current collector 10 and the second current collector 11 each have a sheet shape. The plurality of first current collectors 10 and the plurality of second current collectors 11 are arranged alternately in the stacking direction. Although not shown, the plurality of first current collectors 10 are brought together at one end and connected to a tab extending to the outside of the exterior material 9. Similarly, the plurality of second current collectors 11 are also brought together at one end and connected to the tab.

(power generation element)
Each power generation element 2 is a part that realizes a charging/discharging function. Each power generation element 2 is arranged between a first current collector 10 and a second current collector 11 that are adjacent to each other in the stacking direction. Each power generation element 2 has a solid electrolyte layer 13, a first electrode layer 12, and a second electrode layer 14. The first electrode layer 12 is laminated on one surface of the solid electrolyte layer 13. The second electrode layer 14 is laminated on the other surface of the solid electrolyte layer 13. Each power generation element 2 has a first current collector 10 and a second current collector 11 such that the first electrode layer 12 is connected to the first current collector 10 and the second electrode layer 14 is connected to the second current collector 11. It is arranged between the current collector 11 and the current collector 11 .

The solid electrolyte layer 13 may be any material as long as it is solid and functions as an electrolyte layer in a secondary battery, and its material is not particularly limited. For example, the solid electrolyte layer 13 can be formed of sulfide or oxide. Preferably, solid electrolyte layer 13 includes a sulfide solid electrolyte. Examples of the sulfide solid electrolyte include LPS-based (eg, argyrodite (Li ₆ PS ₅ Cl)) and LGPS-based (eg, Li ₁₀ GeP ₂ S ₁₂ ) materials. The thickness of the solid electrolyte layer 13 is not particularly limited, but is, for example, 5 to 100 μm, preferably 20 to 60 μm.

The first electrode layer 12 and the second electrode layer 14 are layers that each function as an electrode. One of the first electrode layer 12 and the second electrode layer 14 is a positive electrode layer, and the other is a negative electrode layer.

The positive electrode layer may be formed of a material that can release lithium ions during charging and occlude lithium ions during discharging. The positive electrode layer is formed of, for example, a material containing a resin binder and a positive electrode active material dispersed in the resin binder. As the positive electrode active material, for example, lithium metal composite oxide or the like can be used. Examples of lithium metal composite oxides include layered rock salt compounds such as LiCoO ₂ , LiMnO ₂ , LiNiO ₂ , LiVO ₂ , and Li(Ni-Mn-Co)O ₂ , LiMn ₂ O ₄ , and LiNi _0.5 Examples include spinel-type compounds such as Mn _1.5 O ₄ , olivine-type compounds such as LiFePO ₄ and LiMnPO ₄ , and Si-containing compounds such as Li ₂ FeSiO ₄ and Li ₂ MnSiO ₄ . Furthermore, Li ₄ Ti ₅ O ₁₂ or the like can also be used.

The thickness of the positive electrode layer is not particularly limited, but is, for example, 10 to 500 μm, preferably 50 to 200 μm.

The negative electrode layer may be configured to occlude lithium (or deposit lithium) during charging and release lithium ions during discharging. For example, the negative electrode layer can be formed from a material containing a resin binder and a negative electrode active material dispersed in the resin binder. As the negative electrode active material, for example, lithium metal, silicon material (silicon), tin material, compounds containing silicon or tin (oxides, nitrides, alloys with other metals), and carbon materials (graphite, etc.) are used. be able to. The thickness of the negative electrode layer is, for example, 1 to 100 μm, preferably 5 to 80 μm.

In the power generation element 2 having the above-described configuration, during charging, lithium ions move from the positive electrode side to the negative electrode side via the solid electrolyte layer 13, and lithium is occluded in the negative electrode layer. Alternatively, lithium is deposited on the negative electrode side. On the other hand, during discharge, lithium ions move from the negative electrode side to the positive electrode side via the solid electrolyte layer 13, and lithium is inserted into the positive electrode layer. Thereby, the function as a secondary battery is realized.

Note that the power generation element 2 may function as a so-called "all precipitation type" secondary battery. A fully-precipitated secondary battery means that in a fully discharged state, the negative electrode does not contain lithium as a negative electrode active material, and during charging, lithium ions move from the positive electrode to the negative electrode, and lithium metal is deposited on the negative electrode current collector. A battery configured to deposit. In such a battery, at least the lithium metal deposited on the negative electrode side during charging functions as a negative electrode layer, and therefore is included in the power generation element 2 in this embodiment.

Further, in order to prevent the lithium metal deposited in the all-deposition type secondary battery from coming into contact with the solid electrolyte layer 13, a negative electrode intermediate layer may be disposed between the solid electrolyte layer 13 and the negative electrode current collector. The negative electrode intermediate layer is a layer provided between the deposited lithium metal and the solid electrolyte layer. The negative electrode intermediate layer contains a lithium-reactive material. Examples of lithium-reactive materials include materials that can absorb and release lithium ions during charging, and metals that can be alloyed with lithium during charging.

The material capable of intercalating and deintercalating lithium ions is not particularly limited, but carbon materials are preferred. Specific examples of carbon materials include carbon black (specifically, acetylene black, Ketjen black (registered trademark), furnace black, channel black, thermal lamp black, etc.), carbon nanotubes (CNT), graphite, hard carbon, etc. can be mentioned. Among these, carbon black is preferred, and at least one selected from the group consisting of acetylene black, Ketjen black (registered trademark), furnace black, channel black, and thermal lamp black is more preferred.

Examples of metals that can be alloyed with lithium include In, Al, Si, Sn, Mg, Au, Ag, and Zn. Among them, In, Si, Sn, and Ag are preferred, and Ag is more preferred.

The lithium-reactive materials may be used alone or in combination of two or more. As a form in which two or more types are used in combination, it is also preferable to use a material capable of intercalating and deintercalating lithium ions and a metal capable of alloying with lithium. Thereby, sufficient strength and lithium ion conductivity of the negative electrode intermediate layer can be ensured. More specifically, it is preferable to use nanoparticles made of In, Si, Sn, and Ag together with carbon black, and it is more preferable to use nanoparticles made of Ag and carbon black together. When a material capable of intercalating and deintercalating lithium ions and a metal capable of alloying with lithium are used together, the compounding ratio (mass ratio) of these is not particularly limited, but the material capable of intercalating and deintercalating lithium ions: lithium and alloy The ratio of metals that can be converted is preferably 10:1 to 1:1, more preferably 5:1 to 2:1.

The content of the lithium-reactive material in the negative electrode intermediate layer (if two or more materials are used together, it refers to the total content, hereinafter the same) is not particularly limited, but within the range of 50 to 100% by mass. It is preferably within the range of 70 to 100% by mass, more preferably within the range of 85 to 99% by mass, and particularly preferably within the range of 90 to 100% by mass.

The negative electrode intermediate layer may be made of only a lithium-reactive material, as long as a self-supporting film can be formed using only the lithium-reactive material, but it may also contain a binder if necessary. The type of binder is not particularly limited, and any binder known in the technical field can be used as appropriate. Examples include polyvinylidene fluoride (PVDF) (including compounds in which hydrogen atoms are replaced with other halogen elements), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), and carboxymethyl cellulose.

The binder content in the negative electrode intermediate layer is not particularly limited, but is preferably in the range of 1 to 15% by mass, more preferably in the range of 5 to 10% by mass. If the binder content is 1% by mass or more, a negative electrode intermediate layer having sufficient strength can be formed. When the content of the binder is 15% by mass or less, a negative electrode intermediate layer having sufficient lithium ion conductivity can be formed.

The thickness of the negative electrode intermediate layer is not particularly limited, but is preferably 1 to 50 μm, more preferably 5 to 40 μm, and even more preferably 10 to 30 μm. When the thickness of the negative electrode intermediate layer is 1 μm or more, the functions of the negative electrode intermediate layer can be fully exhibited. When the thickness of the negative electrode intermediate layer is 50 μm or less, a decrease in energy density can be suppressed.

Note that FIG. 3 shows, as a preferable example, that the end of the solid electrolyte layer 13 is located outside the end of the first electrode layer 12 and the second electrode layer 14 when viewed along the stacking direction. An example is shown. By employing such a configuration, growth of lithium dendrites that wrap around the ends of the solid electrolyte layer 13 is suppressed. Therefore, short circuit between the first electrode layer 12 and the second electrode layer 14 can be prevented.

Furthermore, when viewed along the stacking direction, the ends of the first electrode layer 12 and the ends of the second electrode layer 14 may be aligned, but they do not need to be aligned. In a preferred example, the end of the negative electrode layer is located outside the end of the positive electrode layer. By employing such a configuration, lithium is prevented from being intensively deposited at the end of the negative electrode layer during charging, and short circuit between the positive electrode and the negative electrode is prevented.

(First insulation part and second insulation part)
Next, the first insulating section 3 and the second insulating section 4 will be explained. As described above, the first insulating part 3 and the second insulating part 4 are provided to apply sufficient pressure to the end of the power generating element 2.

Each first insulating section 3 has a frame shape and is arranged so as to surround the outer peripheral end of each power generating element 2. Similarly, each of the second insulating parts 4 is also frame-shaped, and is arranged so as to surround the outer peripheral end of each of the first insulating parts 3. Like each power generation element 2, each first insulating part 3 and each second insulating part 4 are arranged between a first current collector 10 and a second current collector 11 that are adjacent to each other in the stacking direction. That is, when viewed along the stacking direction, each first current collector 10 and each second current collector 11 is larger than each power generating element 2, and the outer peripheral end thereof is larger than the outer peripheral end of each power generating element 2. It is located on the outside. Then, on the outside of each power generation element 2, each first insulating part 3 and each second insulating part 4 are arranged between the first current collector 10 and the second current collector 11.

As described above, the first insulating section 3 is insulating and made of an elastic body. The first insulating section 3 is compressed. That is, the first insulating section 3 is pressurized along the lamination direction from the elastic sheet 7 via the current collector (first current collector 10 and/or second current collector 11), exterior material 9, etc. , is compressed. The compressed inner peripheral end of the first insulating section 3 is in contact with the outer peripheral end of the power generation element 2 . Further, the compressed outer peripheral end of the first insulating part 3 is in contact with the inner peripheral end of the second insulating part 4.

The Young's modulus of the first insulating portion 3 is, for example, 1 MPa or less. The first insulating section 3 can be made of, for example, a rubber material.

The second insulating portion 4 is provided to prevent the compressed first insulating portion 3 from expanding outward. The second insulating part 4 has a larger Young's modulus than the first insulating part 3. The Young's modulus of the second insulating portion 4 is, for example, 1 MPa or more. The second insulating part 4 can be formed of a rubber member, for example. The inner circumferential end of the second insulating part 4 is in contact with the outer circumferential edge of the compressed first insulating part 3 . Since the Young's modulus of the second insulating portion 4 is greater than that of the first insulating portion 3, outward expansion of the first insulating portion 3 is restricted.

(pressure mechanism)
Next, the elastic sheet 7 and the pressure plate 6 that function as the pressure mechanism 5 will be explained.

As shown in FIG. 3, the elastic sheet 7 is arranged outside the exterior material 9 in the lamination direction. When viewed along the stacking direction, the outer peripheral end of the elastic sheet 7 is located outside the second insulating section 4. The pressure plate 6 is provided outside the elastic sheet 7 in the stacking direction. When viewed along the stacking direction, the outer peripheral end of the pressure plate 6 is located outside the elastic sheet 7. With such a configuration, the power generating element 2, the first insulating part 3, and the second insulating part 4 are pressurized along the stacking direction by the pressure plate 6 via the elastic sheet 7.

Note that the power generation element 2 is usually harder (has a larger Young's modulus) than the first insulating section 3, which is an elastic body. Therefore, the elastic sheet 7 is largely compressed so that the portion overlapping the power generation element 2 is thinner than the portion overlapping the first insulating portion 3 .

As the elastic sheet 7, for example, a material having a Young's modulus of 10 MPa or less can be used. The Young's modulus of the elastic sheet 7 is preferably 0.1 to 10 MPa. As the elastic sheet 7, for example, a sheet made of rubber such as silicone rubber can be used. The thickness of the elastic sheet 7 is, for example, 0.3 to 3 mm, preferably 0.5 to 2 mm.

Next, the operation of the all-solid-state battery 1 according to the present embodiment will be described with reference to reference examples.

FIG. 4A is a cross-sectional view schematically showing an all-solid-state battery according to a reference example. The all-solid-state battery according to this reference example has the same configuration as the all-solid-state battery 1 according to the present embodiment, except that the first insulating part 3 and the second insulating part 4 are missing. In FIG. 4A, the pressure applied from the pressure plate 6 to the power generation element 2 is schematically shown by arrows. As shown in FIG. 4A, in the all-solid-state battery according to the reference example, pressure is applied to the power generation element 2 from the pressure plate 6 via the elastic sheet 7, but the pressure tends to escape outward at the ends. That is, it is difficult to apply force to the ends of the power generation element 2.

On the other hand, FIG. 4B is a schematic diagram showing how pressure is applied in the all-solid-state battery 1 according to the present embodiment. As shown in FIG. 4B, in this embodiment, the power generation element 2 is pressurized along the stacking direction via the elastic sheet 7. Further, the first insulating part 3 and the second insulating part 4 are also pressurized along the stacking direction. Since the first insulating part 3 is an elastic body, it is compressed by applying pressure. A force is generated in the compressed first insulating portion 3 that tends to spread in the lateral direction. As a result, in addition to the force along the stacking direction from the elastic sheet 7, a force from the lateral direction due to the first insulating section 3 is also applied to the end of the power generation element 2. In other words, the force applied to the first insulating part 3 along the stacking direction is converted into a lateral force. Thereby, sufficient pressure can be applied even to the end portions of the power generation element 2 to which pressure is difficult to be applied. Note that the compressed outer peripheral end of the first insulating part 3 is in contact with the inner peripheral end of the second insulating part 4. Since the Young's modulus of the second insulating portion 4 is greater than that of the first insulating portion 3, the outer circumferential end of the first insulating portion 3 is restricted from displacing outward. Thereby, the force applied to the first insulating part 3 through the elastic sheet 7 is difficult to escape to the outside, and is easily directed toward the power generation element 2 side. Also from this point of view, the end portion of the power generation element 2 is sufficiently pressurized. Therefore, it becomes possible to uniformly pressurize the entire surface of the all-solid-state battery 1.

Note that the all-solid-state battery 1 according to this embodiment is used in a pressurized state. Here, the outer circumferential end of the power generation element 2 and the inner circumferential end of the first insulating section 3 only need to be in contact with each other in a pressurized state. The first insulating part 3 and the second insulating part 4 may also be in contact with each other in the pressurized state. In other words, the power generation element 2 and the first insulating section 3 may be arranged so as to be separated from each other if the power generation element 2 is in a non-pressurized state. Similarly, in the non-pressurized state, the first insulating part 3 and the second insulating part 4 may be separated. Below, an example of the arrangement of the first insulating part 3 and the second insulating part 4 in a non-pressurized state will be described.

FIG. 5 is a diagram showing an example of the arrangement of the first insulating part 3 and the second insulating part 4, and is a schematic cross-sectional view showing the configuration of the all-solid-state battery 1 in a non-pressurized state. In the example shown in FIG. 5, the first insulating portion 3 is in contact with the power generation element 2 even in the non-pressurized state. On the other hand, in the non-pressurized state, the first insulating part 3 is separated from the second insulating part 4. According to this example, by arranging the first insulating part 3 so that the first insulating part 3 is in contact with the power generating element 2 even in the non-pressurized state, the end of the power generating element 2 is more easily applied when pressurized. Become more easily pressured.

FIG. 6 is a diagram showing another example of the arrangement of the first insulating part 3 and the second insulating part 4, and is a schematic cross-sectional view showing the configuration of the all-solid-state battery 1 in a non-pressurized state. In the example shown in FIG. 6, in the non-pressurized state, the first insulating part 3 and the power generation element 2 are separated, and the first insulating part 3 and the second insulating part 4 are also separated. The structure of the power generation element 2 may change due to charging and discharging and the like. As shown in FIG. 6, if the first insulating part 3 and the power generating element 2 are arranged apart from each other in the non-pressurized state, the first insulating part 3 will follow the structural change of the power generating element 2. It becomes easier. Therefore, even if the structure of the power generating element 2 changes, it becomes easier to uniformly pressurize the end portions of the power generating element 2.

FIG. 7 is a diagram showing still another example of the arrangement of the first insulating part 3 and the second insulating part 4, and is a schematic cross-sectional view showing the configuration of the all-solid-state battery 1 in a non-pressurized state. In the example shown in FIG. 7, the first insulating portion 3 and the power generation element 2 are separated from each other in the non-pressurized state. On the other hand, the first insulating part 3 and the second insulating part 4 are in contact even in the non-pressurized state. If such a configuration is adopted, since the first insulating part 3 and the power generating element 2 are separated in the non-pressurized state, the first insulating part 3 is separated from the power generating element 2, as in the example shown in FIG. It becomes easier to follow structural changes, and it becomes easier to uniformly pressurize the ends of the power generation element 2. On the other hand, since the first insulating part 3 and the second insulating part 4 are in contact even in the non-pressurized state, the lateral force generated in the first insulating part 3 when pressurized becomes more difficult to escape to the outside. Therefore, the end portion of the power generating element 2 can be pressurized more fully.

FIG. 8 is a diagram showing still another example of the arrangement of the first insulating part 3 and the second insulating part 4, and is a schematic cross-sectional view showing the configuration of the all-solid-state battery 1 in a non-pressurized state. In the example shown in FIG. 8, the first insulating portion 3 and the power generation element 2 are in contact with each other in the non-pressurized state. The first insulating part 3 and the second insulating part 4 are also in contact even in the non-pressurized state. According to such a configuration, as in the example shown in FIG. 5, the first insulating portion 3 is arranged so as to be in contact with the power generation element 2 in the non-pressurized state, so that the power generation element 2 is The ends are more likely to be pressurized. In addition, as in the example shown in FIG. 7, since the first insulating part 3 and the second insulating part 4 are in contact even in the non-pressurized state, in the pressurized state, in addition to the first insulating part 3, The generated force is easily directed toward the power generation element 2 side. Therefore, the end portion of the power generating element 2 can be pressurized more fully.

(Production method)
Next, a method for manufacturing the all-solid-state battery 1 will be described. The method for manufacturing the all-solid-state battery 1 according to the present embodiment may be any method as long as it can arrange the first insulating part 3 and the second insulating part 4 at a position surrounding the end of the power generation element 2, and in particular, Not limited. An example of the manufacturing method will be described below.

[Preparation of positive electrode layer]
A slurry is prepared by weighing and mixing predetermined amounts of a positive electrode active material, a sulfide solid electrolyte, a conductive aid, a binder, and xylene. The obtained slurry is applied to both sides of a carbon-coated Al foil (positive electrode current collector) and dried to produce a positive electrode layer with a thickness of 200 μm (100 μm on one side). Furthermore, rubber materials that will become the first insulating section 3 and the second insulating section 4 are bonded to predetermined positions on the positive electrode current collector.

[Preparation of solid electrolyte layer]
A slurry is prepared by mixing a sulfide solid electrolyte, a binder, and xylene in predetermined amounts. The prepared slurry is applied onto a SUS foil and dried to produce a solid electrolyte layer with a thickness of 40 μm.

[Preparation of negative electrode layer (or negative electrode intermediate layer)]
A predetermined amount of a negative electrode active material (or silver particles and carbon particles when forming a negative electrode intermediate layer), a binder, and NMP (N-methylpyrrolidone) are mixed to prepare a slurry. The prepared slurry is applied onto both sides of a negative electrode current collector (SUS foil) and dried. In this way, a negative electrode layer (or negative electrode intermediate layer) with a thickness of 20 μm (10 μm on one side) is produced. Furthermore, a rubber material that will become the first insulating section 3 and the second insulating section 4 is bonded onto the negative electrode current collector.

[Preparation of positive electrode/solid electrolyte layer laminate]
A solid electrolyte layer is placed on the positive electrode layer, and the solid electrolyte layer is transferred onto the positive electrode layer by roll pressing. As a result, a positive electrode current collector (positive electrode/solid electrolyte layer laminate) in which a positive electrode layer and a solid electrolyte layer are formed is obtained.

[Preparation of electrode laminate]
Subsequently, the negative electrode current collector on which the negative electrode layer (or negative electrode intermediate layer) is formed and the positive electrode current collector on which the positive electrode layer and the like are formed are laminated and roll pressed to obtain an electrode laminate. Note that, if necessary, a plurality of negative electrode current collectors and a plurality of positive electrode current collectors are used. Thereafter, a positive electrode tab (aluminum tab) is bonded to the positive electrode current collector, and a negative electrode tab (nickel tab) is bonded to the negative electrode current collector using an ultrasonic welder. After arranging heat dissipating members on both sides of the electrode laminate as necessary, the electrode laminate is housed in an exterior material (aluminum laminate film) and sealed in vacuum. Thereby, battery cell 8 is obtained. After that, a pair of elastic sheets 7 and a pair of pressure plates 6 are placed. Furthermore, the battery cell 8 is pressurized by binding the pair of pressure plates 6 with a rubber band or the like. Thereby, the all-solid-state battery 1 according to this embodiment can be obtained.

In addition, in this embodiment, the case where the elastic sheet 7 and the pressure plate 6 are used as the pressure mechanism 5 was explained. However, the pressurizing mechanism 5 only needs to be configured to pressurize the power generating element 2 and the first insulating part 3 in the stacking direction, and other configurations may be adopted. For example, it is not necessary that both the power generation element 2 and the first insulating part 3 are pressurized by one elastic sheet 7, and the member that presses the first insulating part 3 and the member that pressurizes the power generation element 2 are separate. It may be a member of

Further, in this embodiment, a case has been described in which the all-solid-state battery 1 has a plurality of power generation elements 2. However, the power generation element 2 does not necessarily need to be provided in plurality, and a single power generation element 2 may be used. In this case, the first current collector 10 and the second current collector 11 may also be each single.

The first embodiment has been described above. Below, typical relationships between the structure and the effects of the all-solid-state battery 1 according to the present embodiment will be summarized.

The all-solid battery 1 according to the present embodiment includes a solid electrolyte layer 13, a first electrode layer 12 laminated on one surface of the solid electrolyte layer 13, and a first electrode layer 12 laminated on the other surface of the solid electrolyte layer 13. A power generation element 2 having a second electrode layer 14, a frame-shaped first insulating part 3 formed of an elastic body and arranged so as to surround the outer peripheral end of the power generation element 2, and a power generation element 2 having a second electrode layer 14; 2 and the first insulating part 3, and a frame-shaped second insulating part 4 arranged so as to surround the outer peripheral end of the first insulating part 3. The Young's modulus of the second insulating section 4 is larger than that of the first insulating section 3. In the state of being pressurized by the pressurizing mechanism 5, the outer peripheral end of the first insulating part 3 is in contact with the second insulating part 4, and the outer peripheral end of the power generation element 2 is pressurized by the first insulating part 3. There is. According to such a configuration, the end portion of the power generation element 2 is pressurized by the compressed first insulating portion 3. At this time, since the outer peripheral end of the first insulating part 3 is in contact with the second insulating part 4 having a larger Young's modulus than the first insulating part 3, the outer peripheral end of the first insulating part 3 is not displaced outward. is regulated. Therefore, the lateral force generated in the compressed first insulating portion 3 tends to be directed toward the power generation element 2 side. Therefore, the power generation element 2 is pressurized with a larger force, and the end portion of the power generation element 2 can be sufficiently pressurized.

In a preferred embodiment, the first insulating part 3 and the second insulating part 4 are configured such that the outer peripheral end of the first insulating part 3 contacts the second insulating part 4 when not compressed. According to such a configuration, the lateral force generated in the compressed first insulating portion 3 is more easily directed toward the power generation element 2 side. Therefore, the end portion of the power generating element 2 can be further sufficiently pressurized.

In a preferred embodiment, the first insulating portion 3 is arranged so as to be separated from the outer peripheral end of the power generating element 2 when not compressed. According to such a configuration, even if a structural change occurs in the power generation element 2, the first insulating portion 3 can easily follow the end portion of the power generation element 2. Therefore, even if the structure of the power generating element 2 changes, the ends of the power generating element 2 can be uniformly pressurized.

In a preferred embodiment, the first insulating portion 3 is arranged so as to be in contact with the outer peripheral end of the power generation element 2 when not compressed. According to such a configuration, the end portion of the power generating element 2 is more easily pressurized by the first insulating portion 3.

In one preferred embodiment, the all-solid-state battery 1 includes a first current collector 10 and a second current collector 11 that are provided to sandwich the power generation element 2 in the stacking direction. When viewed along the stacking direction, the outer circumferential ends of the first current collector 10 and the outer circumferential ends of the second current collector 11 are located on the outer side of the outer circumferential end of the power generation element 2, respectively. The first insulating part 3 and the second insulating part 4 are arranged between the first current collector 10 and the second current collector 11. According to such a configuration, by arranging the first insulating part 3 and the second insulating part 4 between the first current collector 10 and the second current collector 11, the ends of the power generation element 2 can be sufficiently can be pressurized to

(Second embodiment)
Next, a second embodiment will be described. FIG. 9 is a cross-sectional view schematically showing the configuration of the all-solid-state battery 1 according to the second embodiment, and is a diagram showing a state when no pressure is applied. In this embodiment, the frame widths of the first insulating section 3 and the second insulating section 4 are designed. Note that a detailed description of the points that can employ the same configurations as those of the previously described embodiments will be omitted.

Specifically, the frame width L1 of the first insulating section 3 is larger than the frame width L2 of the second insulating section 4. If such a configuration is adopted, the size of the all-solid-state battery 1 can be reduced. That is, the first insulating part 3 desirably has a certain width in order to generate sufficient pressing force in the lateral direction (toward the power generation element 2 side) when compressed along the stacking direction. On the other hand, since the second insulating part 4 only needs to have the function of regulating the outward displacement of the compressed first insulating part 3, it is not necessary to have the width required for the first insulating part 3. do not have. Therefore, the frame width L2 of the second insulating part 4 can be made smaller than the frame width L1 of the first insulating part 3, and thereby the size of the all-solid-state battery 1 can be reduced.

(Third embodiment)
Next, a third embodiment will be described. FIG. 10 is a cross-sectional view schematically showing the configuration of an all-solid-state battery 1 according to the third embodiment, and is a diagram showing a state when no pressure is applied. In this embodiment, the configuration regarding the first insulating section 3 is devised. Note that a detailed description of the points that can employ the same configurations as those of the previously described embodiments will be omitted.

In this embodiment, the first insulating section 3 is joined to the first current collector 10 and not to the second current collector 11. More specifically, the first insulating portion 3 is bonded to both surfaces of the first current collector 10 .

According to this embodiment, process costs can be suppressed. That is, the first insulating portion 3 may be joined only to the first current collector 10 during manufacturing. The step of joining the first insulating section 3 to the second current collector 11 is not necessary. Therefore, the manufacturing process can be shortened and process costs can be suppressed.

Note that in the example shown in FIG. 10, the first insulating section 3 and the second current collector 11 are separated. As shown in this figure, when no pressure is applied, the first insulating part 3 does not necessarily have to be in contact with the upper and lower current collectors, and at least when pressurized, the first insulating part 3 is in contact with the elastic sheet 7 side. It is sufficient if it is configured.

In the example shown in FIG. 10, the end face of the power generation element 2 has unevenness, and the inner peripheral end of the first insulating part 3 fits into the recess of the power generation element 2. Specifically, on the end surface of the power generation element 2, the end of the first electrode layer 12 is located inside the end of the solid electrolyte layer 13. As a result, a recessed portion having the end surface of the first electrode layer 12 as the bottom surface is formed in the end surface of the power generation element 2. The first insulating portion 3 is arranged such that its inner circumferential end portion fits into the recess of the power generation element 2. If such a configuration is adopted, it becomes possible to protect the end surface of the first electrode layer 12 by the first insulating section 3.

(Fourth embodiment)
Next, a fourth embodiment will be described. FIG. 11 is a cross-sectional view schematically showing the configuration of an all-solid-state battery 1 according to the fourth embodiment, and is a diagram showing a state when no pressure is applied. In this embodiment, the configuration regarding the second insulating section 4 is devised. Regarding other points, the same configuration as the third embodiment can be adopted.

Specifically, like the first insulating part 3, the second insulating part 4 is also joined to the first current collector 10, but not to the second current collector 11. More specifically, the second insulating portion 4 is joined to both surfaces of the first current collector 10 .

According to this embodiment, process costs can be further reduced. That is, during manufacturing, the first insulating part 3 and the second insulating part 4 may be joined only to the first current collector 10. There is no need to join the first insulating part 3 and the second insulating part 4 to the second current collector 11. Therefore, the manufacturing process can be shortened, and process costs can be further suppressed.

Further, according to the present embodiment, the outward displacement of the first insulating part 3 is easily regulated by the second insulating part 4. Therefore, the end portion of the power generation element 2 can be further sufficiently pressurized.

(Fifth embodiment)
Next, a fifth embodiment will be described. FIG. 12 is a cross-sectional view schematically showing the configuration of the all-solid-state battery 1 according to the fifth embodiment, and is a diagram showing a state when no pressure is applied. In this embodiment, the configuration regarding the second insulating section 4 is devised. Regarding other points, the same configuration as the third embodiment can be adopted.

In this embodiment, the first insulating section 3 is joined to the first current collector 10 and not to the second current collector 11. On the other hand, the second insulating part 4 is joined to the second current collector 11 and not to the first current collector 10. More specifically, the first insulating portion 3 is bonded to both surfaces of the first current collector 10, and the second insulating portion 4 is bonded to both surfaces of the second current collector 11.

According to this embodiment, the first insulating section 3 only needs to be joined to the first current collector 10 during manufacturing. The second insulating portion 4 may be bonded only to the second current collector 11 . The process of joining the second insulating part 4 to the first current collector 10 is not necessary, and the process of joining the first insulating part 3 to the second current collector 11 is not necessary. Therefore, the manufacturing process can be shortened, and process costs can be further reduced.

Also in this embodiment, since the outward displacement of the first insulating part 3 is restricted by the second insulating part 4, sufficient pressure cannot be applied from the first insulating part 3 to the end of the power generation element 2. can.

(Sixth embodiment)
Next, a sixth embodiment will be described. FIG. 13 is a cross-sectional view schematically showing the configuration of the all-solid-state battery 1 according to the sixth embodiment, and is a diagram showing a state when no pressure is applied. In this embodiment, the configuration regarding the first insulating section 3 is devised. Regarding other points, the same configuration as the embodiment described above can be adopted.

As shown in FIG. 13, in this embodiment, the first insulating section 3 is composed of two first insulating elements (3-1 and 3-2) arranged in the stacking direction. One first insulating element 3-1 is joined to the first current collector 10. The other first insulating element 3-2 is joined to the second current collector 11. By adopting such a configuration, the outward displacement of the first insulating part 3 is regulated by the second insulating part 4, and the force applied to the first insulating part 3 is directed toward the power generation element 2 side. . Therefore, sufficient pressure can be applied to the end of the power generation element 2.

(Seventh embodiment)
Next, a seventh embodiment will be described. FIG. 14 is a cross-sectional view schematically showing the configuration of the all-solid-state battery 1 according to the seventh embodiment, and is a diagram showing a state when no pressure is applied. In this embodiment, the configuration regarding the second insulating section 4 is devised. In other respects, the same configuration as the previously described embodiments, particularly the sixth embodiment, can be adopted.

As shown in FIG. 14, in this embodiment, the second insulating section 4 includes two second insulating elements (4-1 and 4-2) arranged in the stacking direction. One second insulating element 4-1 is joined to the first current collector 10. The other second insulating element 4-2 is joined to the second current collector 11. By adopting such a configuration, the outward displacement of the first insulating part 3 is regulated by the second insulating part 4, and the force applied to the first insulating part 3 is directed toward the power generation element 2 side. . Therefore, sufficient pressure can be applied to the end of the power generation element 2.

(Eighth embodiment)
Next, an eighth embodiment will be described. FIG. 15 is a cross-sectional view schematically showing the configuration of an all-solid-state battery 1 according to the eighth embodiment, and is a diagram showing a state when no pressure is applied. In this embodiment, the configurations regarding the first insulating section 3 and the second insulating section 4 are devised. Regarding other points, the same configuration as the embodiment described above can be adopted.

As shown in FIG. 15, the length T2 of the second insulating section 4 in the stacking direction is longer than the length T1 of the first insulating section 3 in the stacking direction. When such a configuration is adopted, the outward displacement of the first insulating part 3 is more reliably regulated by the second insulating part 4. Therefore, the force applied to the first insulating part 3 is easily directed toward the power generation element 2 side, and more sufficient pressure can be applied to the end of the power generation element 2.

The present invention has been described above using the first to eighth embodiments. Note that these embodiments are not independent of each other and can be used in combination within a consistent range.

DESCRIPTION OF SYMBOLS 1... All-solid-state battery, 2... Power generation element, 3... First insulation part, 4... Second insulation part,
5... Pressure mechanism, 6... Pressure plate, 7... Outer elastic member, 8... Battery cell,
9... Exterior material, 10... First current collector, 11... Second current collector,
12... First electrode layer, 13... Solid electrolyte layer, 14... Second electrode layer

Claims (13)

A power generation element having a solid electrolyte layer, a first electrode layer laminated on one surface of the solid electrolyte layer, and a second electrode layer laminated on the other surface of the solid electrolyte layer;
a frame-shaped first insulating part that is arranged so as to surround the outer peripheral end of the power generation element and is formed of an elastic body;
a pressurizing mechanism that compresses the power generation element and the first insulating part along the stacking direction;
a frame-shaped second insulating part arranged to surround an outer peripheral end of the first insulating part;
Equipped with
The Young's modulus of the second insulating part is greater than the Young's modulus of the first insulating part,
In the state of being pressurized by the pressurizing mechanism, the outer peripheral end of the first insulating part is in contact with the second insulating part, and the outer peripheral end of the power generating element is pressurized by the first insulating part. There is,
All-solid-state battery. The all-solid-state battery according to claim 1,
The first insulating part and the second insulating part are configured such that an outer peripheral end of the first insulating part contacts the second insulating part when uncompressed.
All-solid-state battery. The all-solid-state battery according to claim 1 or 2,
The first insulating part is an all-solid-state battery arranged so as to be separated from the outer peripheral end of the power generation element when not compressed. The all-solid-state battery according to claim 1 or 2,
The first insulating part is arranged so as to be in contact with an outer peripheral end of the power generation element when not compressed.
All-solid-state battery. The all-solid-state battery according to claim 1 or 2,
The frame width of the first insulating part is larger than the frame width of the second insulating part.
All-solid-state battery. The all-solid-state battery according to claim 1,
Furthermore,
a first current collector and a second current collector provided to sandwich the power generation element in the stacking direction;
When viewed along the stacking direction, the outer circumferential edge of the first current collector and the outer circumferential edge of the second current collector are each located outside the outer circumferential edge of the power generation element,
The first insulating part and the second insulating part are arranged between the first current collector and the second current collector,
All-solid-state battery. The all-solid-state battery according to claim 6,
The first insulating part is joined to the first current collector and not joined to the second current collector,
All-solid-state battery. The all-solid-state battery according to claim 7,
The second insulating part is joined to the first current collector and not joined to the second current collector,
All-solid-state battery. The all-solid-state battery according to claim 7,
The second insulating part is joined to the second current collector and not joined to the first current collector.
All-solid-state battery. The all-solid-state battery according to claim 1 or 2,
The first insulating section includes two first insulating elements arranged in the stacking direction.
All-solid-state battery. The all-solid-state battery according to claim 1 or 2,
The second insulating section includes two second insulating elements arranged in the stacking direction.
All-solid-state battery. The all-solid-state battery according to claim 1 or 2,
The length of the second insulating part in the stacking direction is greater than the length of the first insulating part in the stacking direction.
All-solid-state battery. A step of providing an all-solid-state battery,
The all-solid-state battery is
a power generation element having a solid electrolyte layer, a first electrode layer laminated on one surface of the solid electrolyte layer, and a second electrode layer laminated on the other surface of the solid electrolyte layer;
a frame-shaped first insulating part disposed so as to surround an end of the power generation element;
a frame-shaped second insulating part arranged to surround an outer peripheral end of the first insulating part;
a step comprising;
Pressurizing the all-solid-state battery to compress it in the stacking direction;
Equipped with
The pressurizing step includes:
Pressurizing an end of the power generation element via the first insulating part by compressing the first insulating part in the stacking direction;
regulating the compressed outer peripheral end of the first insulating part from being displaced outward by the second insulating part;
Equipped with
How to pressurize all-solid-state batteries.

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