Methods for manufacturing solid electrolyte-containing sheet and electrode laminate for secondary battery, and solid electrolyte-containing sheet

Abstract

This method for manufacturing a solid electrolyte-containing sheet comprises: a precursor preparation step for preparing a precursor 1, wherein the precursor is a composite material including a solid electrolyte, a curable organic material cured by a crosslinking reaction, and a porous sheet; a pressurization step for pressurizing the precursor 1 so that the porous sheet is elastically deformed; and a crosslinking step for performing a crosslinking reaction of the curable organic material in a state in which the porous sheet is elastically deformed.

Description

Method for manufacturing solid electrolyte-containing sheet and electrode laminate for secondary battery, and solid electrolyte-containing sheet

[0001] The present invention relates to a method for producing a solid electrolyte-containing sheet and an electrode laminate for a secondary battery, and a solid electrolyte-containing sheet.

[0002] Secondary batteries using a solid electrolyte layer are known, and examples of such secondary batteries include all-solid-state batteries.

[0003] Solid electrolytes are usually hard and brittle and not self-supporting. Therefore, they are difficult to handle during production. Therefore, a porous sheet such as a nonwoven fabric may be used as a support. Hereinafter, a sheet having a configuration in which a solid electrolyte is supported on a porous sheet is referred to as a solid electrolyte-containing sheet. By combining the solid electrolyte with a porous sheet, the solid electrolyte can be handled as a self-supporting membrane.

[0004] In relation to the above, Patent Document 1 (Japanese Patent Publication No. 2023-522761) discloses an electrochemical cell in which the electrolyte layer is a composite material made of inorganic particles and a crosslinked aprotic polymer.

[0005] Special Publication No. 2023-522761

[0006] In the solid electrolyte layer of a secondary battery, it is desirable for the solid electrolyte particles to be in close contact with each other in order to obtain high ionic conductivity. Therefore, the inventors have investigated a method of supporting a solid electrolyte on a porous sheet and then applying pressure to the porous sheet. By applying pressure, the solid electrolyte particles can be brought into close contact with each other. This reduces grain boundary resistance and increases ionic conductivity.

[0007] However, after the pressure is applied, the porous sheet springs back to its original shape. However, the solid electrolyte does not have the same restoring force. This can result in a gap between the porous sheet and the solid electrolyte. The presence of this gap results in a decrease in ionic conductivity and a deterioration in the secondary battery's performance (e.g., rate characteristics).

[0008] Therefore, an object of the present invention is to provide a technique capable of preventing the generation of spaces due to springback.

[0009] In one aspect, the method for producing a solid electrolyte-containing sheet according to the present invention includes: a precursor-preparing step of preparing a precursor, the precursor being a composite material including a solid electrolyte, a curable organic material that is cured by a crosslinking reaction, and a porous sheet; a pressurizing step of pressurizing the precursor so that the porous sheet is elastically deformed; and a crosslinking step of performing a crosslinking reaction of the curable organic material in a state in which the porous sheet is elastically deformed.

[0010] In one aspect, the method for producing an electrode laminate for a secondary battery according to the present invention includes: a precursor-producing step of producing a precursor for a solid electrolyte layer, the precursor for the solid electrolyte layer being a composite material including a solid electrolyte, a curable organic material that is cured by a crosslinking reaction, and a porous sheet; a step of laminating the precursor for the solid electrolyte layer and an electrode layer to produce a precursor for the electrode laminate; a pressurizing step of pressurizing the precursor for the electrode laminate so that the porous sheet is elastically deformed; and a crosslinking step of performing a crosslinking reaction of the curable organic material in a state in which the porous sheet is elastically deformed.

[0011] In one aspect, the solid electrolyte-containing sheet according to the present invention comprises a cured material layer containing a solid electrolyte and a cured product of a curable organic material, and a porous sheet disposed within the cured material layer, the porous sheet being fixed by the cured material layer in a compressed state within an elastic deformation region.

[0012] Fig. 1 is a schematic cross-sectional view showing a manufacturing method according to an embodiment. Fig. 2 is a schematic cross-sectional view showing a manufacturing method according to a reference example. Fig. 3 is a schematic cross-sectional view showing precursor production example 2. Fig. 4 is a schematic view showing a modified example of an embodiment. Fig. 5 is a schematic view showing an example of a manufacturing method for a laminate for a secondary battery.

[0013] Hereinafter, a method for manufacturing a solid electrolyte-containing sheet according to an embodiment of the present invention will be described with reference to the drawings.

[0014] 1 is a schematic cross-sectional view showing a manufacturing method according to this embodiment. The manufacturing method according to this embodiment generally includes a precursor preparation step (step S1), a pressure application step (step S2), and a cross-linking step (step S3). Each step will be described below.

[0015] (Step S1) Preparation of Precursor First, as shown in Fig. 1(a), a precursor 1 is prepared. The precursor 1 is in the form of a sheet. The precursor 1 is a composite material including a solid electrolyte, a curable organic material that is cured by a crosslinking reaction, and a porous sheet 2.

[0016] In the example shown in Fig. 1(a), the precursor 1 has a porous sheet 2 and a supported layer 3. The supported layer 3 is a layer supported by the porous sheet 2. The supported layer 3 fills the pores of the porous sheet 2. The supported layer 3 contains a solid electrolyte and a curable organic material.

[0017] For example, a nonwoven fabric can be used as the porous sheet 2. When a nonwoven fabric is used, when a cross section of the precursor 1 is observed, the cross section of the fibers constituting the nonwoven fabric is observed to be circular, as shown in FIG. 1( a). Furthermore, the precursor 1 is observed to be disposed within the supported layer 3. Therefore, it can be said that the porous sheet 2 is disposed within the supported layer 3.

[0018] (Step S2) Pressurization Next, as shown in FIG. 1(b), the precursor 1 is pressurized. Specifically, the precursor 1 is pressurized so that the porous sheet 2 is deformed within the elastic deformation region. By pressurizing, the particles of the solid electrolyte in the supported layer 3 are brought into close contact with each other. This reduces the grain boundary resistance and increases the ionic conductivity.

[0019] (Step S3) Crosslinking Next, as shown in FIG. 1( c), a crosslinking reaction of the curable organic material is carried out while the porous sheet 2 is in an elastically deformed state. This causes the supported layer 3 to harden, forming a hardened layer 5. The porous sheet 2 is fixed by the hardened layer 5 while being compressed within the elastic deformation region. This results in a solid electrolyte-containing sheet 4.

[0020] The obtained solid electrolyte-containing sheet 4 has a cured material layer 5 containing a solid electrolyte and a cured product of a curable organic material, and a porous sheet 2 disposed in the cured material layer 5, and the porous sheet 2 is fixed by the cured material layer 5 in a compressed state within the elastic deformation region.

[0021] The obtained solid electrolyte-containing sheet 4 is then combined with an electrode layer and used as a secondary battery. Specifically, a positive electrode layer and a negative electrode layer are disposed so as to sandwich the solid electrolyte-containing sheet 4. Furthermore, the sheet is combined with necessary members such as a current collecting foil and used as a secondary battery.

[0022] According to the method described above, the cross-linking step (S3) is performed, so that the generation of spaces due to springback can be prevented. This point will be described with reference to a reference example.

[0023] Fig. 2 is a schematic cross-sectional view showing a manufacturing method according to a reference example. In this reference example, first, as shown in Fig. 2(a), a precursor 1 is produced. The precursor 1 has a configuration in which a supported layer 3 and a porous sheet 2 are combined. Next, as shown in Fig. 2(b), pressure is applied to the precursor 1, and the porous sheet 2 is compressed within the elastic deformation region. After pressure is applied, the pressure is released as shown in Fig. 2(c). In this reference example, unlike the present embodiment, a cross-linking step is not performed.

[0024] In the method according to the above-described reference example, when the pressure is released, the porous sheet 2 springs back to its original shape. As a result, as shown in Fig. 2(c), a space is generated between the supported layer 3 and the porous sheet 2. The presence of the space impairs the functions of the solid electrolyte layer, such as ionic conductivity.

[0025] Furthermore, in the reference example, in order to avoid springback, it is also possible to apply pressure to the extent that the porous sheet 2 undergoes plastic deformation, as shown in FIG. 2(d). However, in this case, the porous sheet 2 is crushed more than necessary. The porous sheet 2 generally does not have ionic conductivity. Therefore, the ion conduction path (the path from the upper surface to the lower surface of the solid electrolyte layer) may be blocked. As a result, the ionic conductivity of the solid electrolyte layer decreases, and the function of the solid electrolyte layer is also impaired.

[0026] In contrast, according to the present embodiment, the porous sheet 2 is fixed by the cured material layer 5 in the crosslinking step (S3) (see FIG. 1). Therefore, spaces due to springback are unlikely to occur. Furthermore, since the porous sheet 2 is compressed within the elastic deformation region, the porous sheet 2 is not crushed to the extent that the ion conduction pathway is blocked. Therefore, the porous sheet 2 can function well as a solid electrolyte layer.

[0027] The above is an outline of this embodiment. Next, details of this embodiment and preferred embodiments will be described.

[0028] (Porous Sheet) The porous sheet 2 is not particularly limited as long as it has the function of supporting the solid electrolyte. For example, a nonwoven fabric can be used as the porous sheet 2. The thickness of the porous sheet 2 is, for example, 1 to 200 μm, preferably 1 to 100 μm, preferably 3 to 100 μm, more preferably 3 to 50 μm, and even more preferably 3 to 20 μm.

[0029] The porous sheet 2 may be configured to react directly with the curable organic material during the crosslinking process. Using such a material can more reliably prevent the generation of voids due to springback. For example, if the porous sheet has reactive functional groups (such as epoxy groups, mercapto groups, and vinyl groups) that undergo crosslinking, the curable organic material and the porous sheet can be directly reacted.

[0030] (Curable Organic Material) The curable organic material is not particularly limited as long as it has the function of being cured by a crosslinking reaction. The curable organic material may be a thermosetting material or a photocurable (energy ray curable) material. That is, in the crosslinking step, the curable organic material may be crosslinked by heat or by energy rays such as UV.

[0031] For example, a composition containing a curable monomer or a curable resin can be used as the curable organic material. Examples of such compositions include UV-curable urethane acrylate and epoxy-based resin compositions. The curable organic material may also contain a radical initiator or the like. Such a composition may also contain a binder. The content of the curable organic material is, for example, 0.5 to 20 parts by mass, based on 100 parts by mass of the solid electrolyte.

[0032] (Solid Electrolyte) The solid electrolyte is not particularly limited as long as it functions as an electrolyte layer in a secondary battery. For example, sulfides and oxides can be used as the solid electrolyte. As the sulfide solid, for example, LPS-based (e.g., Argyrodite (Li ６ P.S. ５ Cl), and LGPS systems (e.g., Li １０ GeP ２ S １２ ) materials can be mentioned.

[0033] (Precursor Preparation Step S1) In the precursor preparation step (step S1), as described above, a composite material including a solid electrolyte, a curable organic material, and a porous sheet is prepared as a precursor. The method for preparing the precursor is not particularly limited. The precursor may further contain a dispersion medium or the like. The use of a dispersion medium makes it easier to fill the porous sheet with the solid electrolyte.

[0034] For example, the precursor 1 can be produced by the following Production Examples 1 to 3.

[0035] [Precursor Preparation Example 1] In Preparation Example 1, first, a nonwoven fabric or the like is prepared as a porous sheet. Then, a slurry containing a solid electrolyte, a curable organic material, and a dispersion medium is prepared and applied to the porous sheet. As a result, the porous sheet is filled with the solid electrolyte and the curable organic material, and precursor 1 is obtained. As described above, the use of a dispersion medium makes it easier to fill the porous sheet with the solid electrolyte. Therefore, it is possible to more reliably prevent the generation of a space between the porous sheet and the solid electrolyte sheet, and more reliably prevent a decrease in ionic conductivity.

[0036] (Precursor Production Example 2) Next, Production Example 2 will be described. Fig. 3 is a schematic cross-sectional view showing Production Example 2. In Production Example 2, a precursor 1 is produced by stacking a first precursor layer 6 and a second precursor layer 7.

[0037] Specifically, first, a porous sheet and a sheet containing a curable organic material are prepared as the first precursor layer 6. For example, a slurry containing the curable organic material is applied to the porous sheet 2. In this way, the first precursor layer 6 is obtained.

[0038] Next, as shown in FIG. 3( a), a second precursor layer 7 is laminated on the first precursor layer 6. The second precursor layer 7 is a layer containing a solid electrolyte and a curable organic material but not a porous sheet 2. For example, a slurry containing a solid electrolyte and a curable organic material, and optionally a dispersion medium, is prepared as a slurry for forming the second precursor layer. The prepared slurry is then applied to the surface of the first precursor layer 6. This results in the second precursor layer 7 being formed on the first precursor layer 6, thereby obtaining the precursor 1. Alternatively, a sheet containing a solid electrolyte and a curable organic material may be prepared in advance and then attached to the first precursor layer 6. This method also allows the second precursor layer 7 to be formed on the first precursor layer 6, thereby obtaining the precursor 1. The second precursor layer 7 may be disposed on only one side of the first precursor layer 6, or may be disposed on both sides.

[0039] The resulting precursor 1 is then pressed and further cross-linked as shown in FIG. 3(b).

[0040] In this example, the content (mass %) of the curable organic material in the first precursor layer 6 is preferably greater than the content (mass %) of the curable organic material in the second precursor layer 7. By adopting such a configuration, the concentration of the curable organic material is increased around the porous sheet 2 (first precursor layer 6). Therefore, when the crosslinking process is performed, the porous sheet 2 is more firmly fixed, making it less likely that gaps will form due to springback. Meanwhile, the concentration of the curable organic material is reduced in other areas (second precursor layer 7). Curable organic materials do not typically contribute to ionic conduction. Therefore, if the concentration of the curable organic material in other areas is low, the decrease in ionic conductivity due to the influence of the curable organic material can be minimized.

[0041] (Precursor Preparation Example 3) Next, Preparation Example 3 will be described. In Preparation Example 3, a porous sheet and a curable organic material are combined, and then a solid electrolyte is filled. Specifically, first, a composite of a porous sheet and a curable organic material is prepared as a third precursor layer. For example, a slurry containing a curable organic material is applied to the porous sheet. This produces a sheet-like third precursor layer. Next, a powdered solid electrolyte is filled into the third precursor layer. This allows precursor 1 to be obtained.

[0042] In Preparation Example 3, as in Preparation Example 2, the concentration of the curable organic material is high around the periphery of the porous sheet and low in other areas, thereby more reliably preventing the generation of voids due to springback and minimizing the decrease in ionic conductivity.

[0043] (Pressing Step and Crosslinking Step) Next, the pressing step (S2) and the crosslinking step (S3) will be described (see FIG. 1).

[0044] In the pressurizing step (S2), pressure may be applied to the precursor 1 so that the porous sheet 2 is compressed within the elastic deformation region. For example, the pressurizing step can be performed by a roll press.

[0045] The crosslinking step (S3) may be any step of crosslinking the curable organic material so as to harden it to a degree that suppresses the generation of voids due to springback. As described above, the crosslinking step may be a UV crosslinking treatment, a thermal crosslinking treatment, or a combination of both. By using a UV crosslinking treatment or a thermal crosslinking treatment, the timing of curing can be set as desired.

[0046] The cross-linking step (S3) may be carried out at any time when the porous sheet 2 is in a compressed state within the elastic deformation region.

[0047] For example, the crosslinking step (S3) may be performed simultaneously with the pressurizing step (S2). That is, the crosslinking step may be performed while the precursor 1 is under pressure.

[0048] On the other hand, the crosslinking step (S3) may be performed after the pressurizing step (S2) is completed. That is, the crosslinking step (S3) may be performed after the precursor 1 is pressurized and the pressure is released. Even if the pressure applied to the precursor 1 is released after the pressurizing step is performed, the porous sheet 2 remains in a compressed state within a certain period of time. Therefore, within such a period of time, the crosslinking step (S3) may be performed after the pressurizing step (S2) is completed.

[0049] (Modification) Next, a preferred modification of the present embodiment will be described. Fig. 4 is a schematic diagram showing the modification of the present embodiment. In this modification, the pressurizing step (S2) includes a preliminary pressurizing step, a roll body preparation step, and a main pressurizing step.

[0050] Specifically, in this modified example, a long sheet is produced as the precursor 1. After the precursor 1 is produced, the precursor 1 is pre-pressurized at a pre-pressurization pressure. After the pre-pressurization, the precursor 1 is wound into a roll to obtain a roll body 8. The roll body 8 is stored as needed. Thereafter, when it is used (when manufacturing a secondary battery), the precursor 1 is unwound from the roll body 8. Then, a main pressurization step is carried out. In the main pressurization step, the precursor 1 is pressurized at a pressure greater than the pre-pressurization pressure.

[0051] According to this modification, by applying pre-pressurization, the solid electrolyte and other components can be supported on the porous sheet in the precursor 1 with enough strength to prevent them from falling off. On the other hand, if the pre-pressurization pressure is too high, the precursor 1 loses flexibility and becomes difficult to wind into a roll. Therefore, in this modification, pre-pressurization is performed at a pressure lower than the pressure applied during main pressurization. This allows the precursor 1 to retain flexibility enough to be wound into a roll even after pre-pressurization. This allows the precursor 1 to be stored in a rolled state until use (when manufacturing a secondary battery), making it easier to proceed with the manufacturing process without delay. Finally, by applying main pressurization, the solid electrolyte particles can be tightly attached to each other, thereby increasing ionic conductivity.

[0052] In this modification, the cross-linking step may be performed at a timing when the porous sheet is maintained in a compressed state within the elastic deformation region. For example, the cross-linking step may be performed immediately before the main pressurizing step (between the time when the roll body 8 is unwound and the main pressurizing step), simultaneously with the main pressurizing step, or after the main pressurizing step.

[0053] (Example of application to a method for manufacturing an electrode laminate for a secondary battery) The method for manufacturing a solid electrolyte-containing sheet described above can be applied to a method for manufacturing an electrode laminate for a secondary battery. An example of a method for manufacturing an electrode laminate for a secondary battery will be described below.

[0054] 5A and 5B are schematic diagrams showing an example of a method for manufacturing a laminate for a secondary battery. First, as shown in FIG. 5A, a precursor 9 for a solid electrolyte layer is prepared. The precursor 9 for a solid electrolyte layer may be the same as the "precursor 1" described above. That is, a composite material containing a solid electrolyte, a curable organic material, and a porous sheet is prepared as the precursor 9 for a solid electrolyte layer.

[0055] Next, as shown in FIG. 5( b), the solid electrolyte layer precursor 9 and the electrode layer 10 are laminated to produce the electrode laminate precursor 11. Then, as shown in FIG. 5( c), the electrode laminate precursor 11 is pressed. At this time, the electrode laminate precursor 11 is pressed so that the porous sheet is deformed within the elastic deformation region, similar to the previously described step S2 (pressing step). Thereafter, as with the previously described step S3 (crosslinking step), a crosslinking reaction of the curable organic material is carried out while the porous sheet is in an elastically deformed state. This results in a secondary battery laminate. It can also be said that the obtained secondary battery laminate contains the solid electrolyte-containing sheet 4 described in the previously described embodiment, derived from the solid electrolyte layer precursor 9.

[0056] This method can achieve the same effects as the method for manufacturing a solid electrolyte-containing sheet according to the embodiment described above. In addition, since pressure is applied after the electrode laminate precursor 11 is produced, only one pressure application step is required. In other words, there is no need to apply pressure separately to bond the solid electrolyte particles together and to combine the solid electrolyte sheet with the electrode layer. This is advantageous in that it does not increase the number of manufacturing processes.

[0057] [Examples] Next, examples carried out by the present inventors will be described in order to explain the present invention in more detail, although the present invention should not be construed as being limited to the following examples.

[0058] Example 1 A solid electrolyte and a curable organic material (UV-curable urethane acrylate) were placed in a mortar and mixed. The mixing ratio of the solid electrolyte to the curable organic material was 95:5 by mass. The resulting mixture was applied to a nonwoven fabric to obtain a precursor. The resulting precursor was pressed. Immediately after pressing, a UV crosslinking treatment was performed on the nonwoven fabric in an elastically deformed state to cure the curable organic material, thereby obtaining a solid electrolyte-containing sheet according to Example 1. When a cross section of the resulting solid electrolyte-containing sheet was observed under a microscope, no space was observed around the nonwoven fabric.

[0059] Comparative Example 1: After pressing the precursor, no UV curing treatment was performed. After some time had passed, the cross section of the solid electrolyte-containing sheet was observed under a microscope, and spaces were observed around the nonwoven fabric.

[0060] From the above comparison results between Example 1 and Comparative Example 1, it was confirmed that the generation of spaces due to springback can be prevented by performing a crosslinking treatment while the nonwoven fabric (porous sheet) is in an elastically deformed state.

[0061] [Appendix] Next, the main configurations and effects of the present invention will be summarized as appendices.

[0062] (Supplementary Note 1) A method for producing a solid electrolyte-containing sheet, comprising: a precursor preparation step (S1) of preparing a precursor 1, the precursor being a composite material including a solid electrolyte, a curable organic material that is cured by a crosslinking reaction, and a porous sheet 2; a pressurizing step (S2) of pressurizing the precursor 1 so that the porous sheet 2 is elastically deformed; and a crosslinking step (S3) of performing a crosslinking reaction of the curable organic material in a state in which the porous sheet 2 is elastically deformed.

[0063] According to this method, the porous sheet 2 is fixed by the curable organic material in the cross-linking step, which prevents the generation of voids due to springback.

[0064] (Supplementary Note 2) The production method according to Supplementary Note 1, wherein the crosslinking step (S3) is carried out in the pressurizing step (S2).

[0065] According to this method, the crosslinking reaction of the curable organic material can be carried out while the porous sheet 2 is in an elastically deformed state.

[0066] (Appendix 3) The manufacturing method according to Appendix 1 or 2, wherein the precursor manufacturing step (S1) includes a step of manufacturing a first precursor layer 6 including a porous sheet and a curable organic material, and a step of laminating a second precursor layer 7 including a solid electrolyte and a curable organic material but not including a porous sheet on the first precursor layer 6, and the content (mass %) of the curable organic material in the first precursor layer 6 is greater than the content (mass %) of the curable organic material in the second precursor layer 7.

[0067] According to this method, the density of the curable organic material is increased around the porous sheet, so that the porous sheet is more reliably fixed in the crosslinking step (S3). This more reliably prevents the generation of voids. Meanwhile, the density of the curable organic material is low in other areas, so that the effect of the curable organic material on ionic conductivity can be minimized.

[0068] (Supplementary Note 4) The manufacturing method according to Supplementary Note 1 or 2, wherein the precursor preparation step (S1) includes the steps of preparing a third precursor layer including a porous sheet and a curable organic material, and filling the third precursor layer with a solid electrolyte.

[0069] According to this method, the density of the curable organic material is increased around the porous sheet, so that the porous sheet is more reliably fixed in the crosslinking step (S3). This more reliably prevents the generation of voids. Meanwhile, the density of the curable organic material is low in other areas, so that the effect of the curable organic material on ionic conductivity can be minimized.

[0070] (Appendix 5) The production method according to any one of Appendices 1 to 4, wherein the precursor further contains a dispersion medium.

[0071] According to this method, the use of a dispersion medium makes it easier to fill the porous sheet with the solid electrolyte.

[0072] (Supplementary Note 6) The manufacturing method according to any one of Supplementary Notes 1 to 5, wherein the crosslinking step (S3) includes a step of crosslinking the precursor using heat or UV.

[0073] According to this method, the timing of crosslinking (curing) can be set arbitrarily.

[0074] (Supplementary Note 7) The manufacturing method according to any one of Supplementary Notes 1 to 6, wherein the crosslinking step includes a step of directly reacting the curable organic material with the porous sheet.

[0075] According to this method, it becomes more difficult for spaces to occur around the porous sheet.

[0076] (Appendix 8) The manufacturing method according to any one of Appendices 1 to 7, wherein the pressurizing step (S2) includes: a preliminary pressurizing step of pressurizing the precursor 1 at a preliminary pressurizing pressure; a step of winding the precursor 1 into a roll after the preliminary pressurizing step to prepare a precursor roll body 8; and a main pressurizing step of pressurizing the precursor at a pressure greater than the preliminary pressurizing pressure after the step of preparing the roll body.

[0077] This method allows the precursor to be stored in roll form until needed, allowing the manufacturing process to proceed smoothly.

[0078] (Appendix 9) A method for manufacturing an electrode laminate for a secondary battery, comprising: a precursor-producing step of producing a precursor for a solid electrolyte layer (9), the precursor for the solid electrolyte layer being a composite material including a solid electrolyte, a curable organic material that is cured by a crosslinking reaction, and a porous sheet; a step of laminating the precursor for the solid electrolyte layer (9) and an electrode layer (10) to produce a precursor for an electrode laminate (11); a pressurizing step of pressurizing the precursor for the electrode laminate (11) so that the porous sheet is elastically deformed; and a crosslinking step of performing a crosslinking reaction of the curable organic material in a state in which the porous sheet is elastically deformed.

[0079] According to this method, the application of pressure to bond the solid electrolyte particles together and the application of pressure to obtain the electrode stack can be carried out in the same step, thereby reducing the number of manufacturing processes.

[0080] (Appendix 10) A solid electrolyte-containing sheet comprising: a cured material layer 5 containing a solid electrolyte and a cured product of a curable organic material; and a porous sheet 2 disposed in the cured material layer, wherein the porous sheet 2 is fixed by the cured material layer 5 in a compressed state within an elastic deformation region.

[0081] According to this configuration, a solid electrolyte-containing sheet in which spaces are unlikely to occur around the porous sheet 2 can be obtained.

[0082] (Incorporation by Reference) The present invention claims priority based on Japanese Patent Application No. 2024-117249 (filing date: July 22, 2024), the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A method for producing a solid electrolyte-containing sheet, comprising: a precursor-preparing step of preparing a precursor, the precursor being a composite material including a solid electrolyte, a curable organic material that is cured by a crosslinking reaction, and a porous sheet; a pressurizing step of pressurizing the precursor so that the porous sheet is elastically deformed; and a crosslinking step of crosslinking the curable organic material while the porous sheet is in a state where it is elastically deformed.

2. The manufacturing method according to claim 1, wherein the crosslinking step is carried out in the pressure application step.

3. A manufacturing method according to claim 1 or 2, wherein the precursor preparation step comprises the steps of: preparing a first precursor layer containing the porous sheet and the curable organic material; and laminating, on the first precursor layer, a second precursor layer containing the solid electrolyte and the curable organic material but not the porous sheet; and wherein the content (mass %) of the curable organic material in the first precursor layer is greater than the content (mass %) of the curable organic material in the second precursor layer.

4. A manufacturing method according to claim 1 or 2, wherein the precursor preparation step comprises the steps of: preparing a third precursor layer containing the porous sheet and the curable organic material; and filling the third precursor layer with the solid electrolyte.

5. A manufacturing method according to claim 1 or 2, wherein the precursor further contains a dispersion medium.

6. A manufacturing method according to claim 1 or 2, wherein the cross-linking step includes a step of cross-linking the precursor using heat or UV.

7. A manufacturing method according to claim 1 or 2, wherein the crosslinking step includes a step of directly reacting the curable organic material with the porous sheet.

8. A manufacturing method according to claim 1 or 2, wherein the pressurizing step comprises: a preliminary pressurizing step of pressurizing the precursor at a preliminary pressurizing pressure; a step of winding the precursor into a roll after the preliminary pressurizing step to prepare a roll body of the precursor; and a main pressurizing step of pressurizing the precursor at a pressure greater than the preliminary pressurizing pressure after the step of preparing the roll body.

9. A method for manufacturing an electrode laminate for a secondary battery, comprising: a precursor-producing step of producing a precursor for a solid electrolyte layer, the precursor for the solid electrolyte layer being a composite material including a solid electrolyte, a curable organic material that is cured by a crosslinking reaction, and a porous sheet; a step of laminating the precursor for the solid electrolyte layer and an electrode layer to produce a precursor for an electrode laminate; a pressurizing step of pressurizing the precursor for the electrode laminate so that the porous sheet is elastically deformed; and a crosslinking step of performing a crosslinking reaction of the curable organic material while the porous sheet is in a state where it is elastically deformed.

10. A solid electrolyte-containing sheet comprising: a cured material layer containing a solid electrolyte and a cured product of a curable organic material; and a porous sheet disposed within the cured material layer, wherein the porous sheet is fixed by the cured material layer in a compressed state within an elastic deformation region.

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