JP2018125268A - Method of manufacturing all solid state battery and all solid state battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily prevent reduction of battery energy density of an all solid state battery.SOLUTION: In a method of manufacturing an all solid state battery, a step of forming a single cell unit (2) including an electrode layer body (3) in which a positive electrode layer (4), a solid electrolyte layer (5), and a negative electrode layer (6) are laminated, a positive electrode current collector (7), and a negative electrode current collector (8) includes a step of forming a bending prevention part (9) for preventing the electrode layer body (3) to be bent is formed on the outer edge of the positive electrode current collector (7) and the negative electrode current collector (8).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing an all-solid battery and an all-solid battery including a cathode layer, a solid electrolyte layer, and an anti-bending portion that prevents the anode layer from bending.

  In recent years, all-solid secondary batteries using a lithium ion conductive solid electrolyte as the battery electrolyte are known. The all-solid-state secondary battery includes an electrode layer body laminated so that a solid electrolyte layer is disposed between a positive electrode layer and a negative electrode layer, and a positive electrode current collector disposed on the side of the positive electrode layer opposite to the solid electrolyte layer. And a negative electrode current collector disposed on the side of the negative electrode layer opposite to the solid electrolyte layer.

  Here, the positive electrode layer includes a positive electrode active material and a lithium ion conductive solid electrolyte. The negative electrode layer includes a negative electrode active material and a lithium ion conductive solid electrolyte. The solid electrolyte layer is disposed between the positive electrode layer and the negative electrode layer. The positive electrode current collector is made of metal and is provided on the surface of the positive electrode layer. The negative electrode current collector is made of metal and is provided on the surface of the negative electrode layer.

  This all solid state secondary battery is manufactured as follows, for example. First, a powdery positive electrode layer is formed on the positive electrode current collector. Thereafter, a powdery solid electrolyte layer is formed on the positive electrode layer. Next, a powdery negative electrode layer is formed on the solid electrolyte layer. Then, these layers thus formed are pressure-molded at a high pressure with a hydraulic press or the like to produce an all-solid-state secondary battery.

  However, in the manufacturing method as described above, internal stress generated in the electrode layer body constituted by the powdery positive electrode layer, the powdery solid electrolyte layer, and the powdery negative electrode layer, the flow of the powder Due to the poor nature and the frictional force between the powders, the pressure acting on the electrode layer body is uneven. Further, if there is a wall made of resin or the like around the electrode layer body, unevenness occurs in the pressure acting on the electrode layer body due to wall friction between the electrode layer body and the wall. Further, the pressure acting on the electrode layer body becomes uneven due to the frictional force between the positive electrode current collector or the negative electrode current collector and the electrode layer body. And there is a problem that density unevenness occurs in the electrode layer body due to such pressure unevenness, and the electrode layer body is curved.

  Patent Document 1 is known as a means for solving such a problem of bending of the electrode layer body. Similar to the all-solid secondary battery described above, the secondary battery described in Patent Document 1 includes an electrode layer body laminated such that a solid electrolyte layer is disposed between the positive electrode layer and the negative electrode layer, and a positive electrode layer. A positive electrode current collector disposed on the opposite side of the solid electrolyte layer, and a negative electrode current collector disposed on the negative electrode layer on the opposite side of the solid electrolyte layer. Then, an anti-bending part (reinforcing layer) for preventing the electrode layer body from being bent is bonded to the side opposite to the positive electrode layer of the positive electrode current collector, and the above-mentioned anti-bending part is also bonded to the side opposite to the negative electrode layer of the negative electrode current collector. doing.

JP 2012-59472 A (published on March 22, 2012)

  In the technique described in Patent Document 1 as described above, a bending prevention portion for preventing the bending of the electrode layer body is bonded to the surface of the positive electrode current collector opposite to the positive electrode layer, and the negative electrode current collector Adhere to the opposite side. For this reason, in order to reduce the weight and volume of the completed secondary battery and prevent the battery energy density from being lowered, if the anti-bending part is removed from the secondary battery, the side opposite to the positive electrode layer of the positive electrode current collector Therefore, it is necessary to remove the anti-bending part that adheres to the surface of the negative electrode, and to remove the anti-bending part that adheres to the surface of the negative electrode current collector opposite to the negative electrode layer.

  However, since the positive electrode current collector, the negative electrode current collector, and the anti-bending part are all thin films, the anti-bending part adhered to the surface of the positive electrode current collector opposite to the positive electrode layer, and the negative electrode current collector It is not easy to perform the work of peeling off the anti-bending part adhered to the surface of the body opposite to the negative electrode layer. Therefore, there is a problem that it is difficult to reduce the battery energy density by reducing the weight and volume of the completed secondary battery.

  Moreover, when laminating an electrode layer body, there exists a problem that a curve prevention part cannot be peeled off. Alternatively, the anti-bending part must be peeled off before stacking, and there is a problem that the electrode layer body is bent during stacking.

  One aspect of the present invention is to manufacture an all-solid battery that can easily reduce the weight and volume of a completed all-solid battery and easily prevent a decrease in battery energy density while reducing the curvature of the electrode layer body. The object is to realize a method and an all-solid-state battery.

  In order to solve the above-described problem, the method for manufacturing an all-solid battery according to one embodiment of the present invention includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, wherein the solid electrolyte is between the positive electrode layer and the negative electrode layer. An electrode layer body laminated so that a layer is disposed, a positive electrode current collector disposed on the opposite side of the positive electrode layer from the solid electrolyte layer and having a larger area than the electrode layer body, and the negative electrode layer A step of forming a unit cell unit including a negative electrode current collector that is disposed on the opposite side of the solid electrolyte layer and has a larger area than the electrode layer body, and the step of forming the unit cell unit includes the step of forming the unit cell unit The anti-bending part is formed by the anti-bending part forming step of forming an anti-bending part for preventing the bending at the outer edge of at least one of the positive electrode current collector and the negative electrode current collector, and the anti-bending part forming step. Unit cell unit along the stacking direction of the electrode layer body Characterized in that it comprises a pressing step of pressing.

  In order to solve the above-described problem, another method for producing an all-solid battery according to one embodiment of the present invention includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer that are disposed between the positive electrode layer and the negative electrode layer. An electrode layer body laminated such that a solid electrolyte layer is disposed; a positive electrode current collector disposed on a side opposite to the solid electrolyte layer of the positive electrode layer and having a larger area than the electrode layer body; and the negative electrode layer Including a unit cell unit forming step of forming a plurality of unit cell units including a negative electrode current collector disposed on the opposite side of the solid electrolyte layer and having a larger area than the electrode layer body. A plurality of forming steps forms an anti-bending portion that prevents the electrode layer body from bending at an outer edge of at least one of the positive electrode current collector and the negative electrode current collector of the plurality of unit cell units. Forming step and the plurality of unit cell units Characterized in that it comprises a laminating step of forming a laminate battery unit to which a layer, a pressing step of pressing along the laminated cell unit is stacked by the stacking step in the stacking direction of the electrode layers thereof.

  In order to solve the above problems, an all solid state battery according to one embodiment of the present invention includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, wherein the solid electrolyte layer is disposed between the positive electrode layer and the negative electrode layer. The electrode layer body laminated as described above, the positive electrode current collector disposed on the opposite side of the positive electrode layer from the solid electrolyte layer and having a larger area than the electrode layer body, and the solid electrolyte layer of the negative electrode layer A negative electrode current collector having a larger area than the electrode layer body, and at least one of the positive electrode current collector and the negative electrode current collector to prevent the electrode layer body from being bent And an anti-bending portion formed on the outer edge.

  According to one aspect of the present invention, it is possible to easily reduce the weight and volume of the completed all-solid battery and easily prevent the battery energy density from being lowered while reducing the curvature of the electrode layer body. Play.

3 is a cross-sectional view showing a configuration of a unit cell unit of an all solid lithium ion secondary battery according to Embodiment 1. FIG. FIG. 2 is a plan sectional view taken along a plane AA shown in FIG. 1. It is a perspective view which shows the manufacturing method of the all-solid-state lithium ion secondary battery which concerns on Embodiment 3. FIG. FIG. 6 is a cross-sectional view showing a bending prevention part provided in a single battery unit according to Embodiment 4.

  Hereinafter, the all solid state secondary battery according to the embodiment of the present invention will be described in detail. In this embodiment, as an example of an all-solid secondary battery, an all-solid secondary battery including a solid electrolyte having lithium ion conductivity, that is, an all-solid lithium ion secondary battery will be described.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing a configuration of a unit cell unit 2 of an all-solid-state lithium ion secondary battery 1 (all-solid-state battery) according to Embodiment 1. First, the basic configuration of the all solid lithium ion secondary battery 1 will be described. The all solid lithium ion secondary battery 1 includes an electrode including a positive electrode layer 4, a negative electrode layer 6, and a solid electrolyte layer 5 made of a lithium ion conductive solid electrolyte disposed between the positive electrode layer 4 and the negative electrode layer 6. A layer body 3 is provided. A positive electrode current collector 7 having a larger area than the electrode layer body 3 is laminated on the surface of the positive electrode layer 4 opposite to the solid electrolyte layer 5. A negative electrode current collector 8 having a larger area than the electrode layer body 3 is laminated on the surface of the negative electrode layer 6 opposite to the solid electrolyte layer 5. The positive electrode layer 4 and the negative electrode layer 6 function as electrodes of the all solid lithium ion secondary battery 1.

  The components of the positive electrode current collector 7, the positive electrode layer 4, the solid electrolyte layer 5, the negative electrode layer 6, and the negative electrode current collector 8 are referred to as “unit cell unit” in this specification. The positive electrode layer 4 or the negative electrode layer 6 (hereinafter collectively referred to as “collector”) is formed on both the front and back surfaces of the positive electrode current collector 7 or negative electrode current collector 8 (hereinafter sometimes collectively referred to as “current collector”). In a battery called a bi-cell type or bipolar type in which the electrode layer is disposed), an electrode layer disposed on the surface of one current collector and an electrode layer disposed on the back surface are connected to the current collector. Share your body. Since the bi-cell type battery is configured in this way, it cannot be cut out into a single cell unit, but the repeating unit of the stacked structure of the bi-cell type battery is referred to as a “single cell unit”. The present invention can also be applied to a bi-cell or bipolar battery.

For the positive electrode layer 4, a mixture of a positive electrode active material and a solid electrolyte or only a positive electrode active material is used. The weight ratio between the positive electrode active material and the solid electrolyte in the mixture is, for example, 7: 3. Here, for the positive electrode active material, lithium cobalt acid (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), and other materials that are usually used for the positive electrode active material in the lithium ion battery field are used. Can be used.

  For the negative electrode layer 6, a mixture of a negative electrode active material and a solid electrolyte or only a negative electrode active material is used. The weight ratio between the negative electrode active material and the solid electrolyte in the negative electrode active material is, for example, 6: 4. Here, as the negative electrode active material, natural graphite, artificial graphite, graphite carbon fiber, carbon material represented by resin-fired carbon, tin, lithium, oxide, sulfide, nitride, alloy, etc., powder Regardless of the shape of the foil and the like, a material usually used for the negative electrode active material in the lithium ion battery field can be used.

Solid electrolytes used for the positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode layer 6 include materials made of organic compounds, materials made of inorganic compounds, materials made of organic compounds and inorganic compounds, or lithium ion batteries. Commonly used materials are used. Among the inorganic compounds, for example, sulfides such as Li ₂ S—P ₂ S ₅ are superior in ion conductivity compared to other inorganic compounds.

  The positive electrode current collector 7 and the negative electrode current collector 8 include a plate made of copper, magnesium, stainless steel, titanium, iron, cobalt, nickel, zinc, aluminum, germanium, indium, lithium, tin, or an alloy thereof. A sheet, a foil, a powder, or a film-formed body is used.

  The surface roughness of at least one of the positive electrode current collector 7 and the negative electrode current collector 8 is preferably Rz = 1.0 μm or more.

  The formation method of the positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode layer 6 is not specifically limited. For example, the positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode layer 6 may be stacked by electrostatic spraying, dry squeegee film formation, or dry film formation such as electrostatic coating. Moreover, the positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode layer 6 are mixed with a solvent and a binder, and are applied in a slurry or solution to be applied and dried, thereby drying the positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode. A powder film constituting the layer 6 may be formed. However, in order to reduce the contact resistance by eliminating the interface of the powder film constituting the positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode layer 6, the positive electrode layer is required until the all solid lithium ion secondary battery 1 is completed. 4. It is necessary to perform the pressurization process which pressurizes the solid electrolyte layer 5 and the negative electrode layer 6 along the lamination direction.

  In the present embodiment, an anti-bending portion 9 that prevents the electrode layer body 3 from bending is formed on at least one outer edge of the positive electrode current collector 7 and the negative electrode current collector 8. As long as the positive electrode current collector 7 and the negative electrode current collector 8 are not short-circuited, the bending prevention unit 9 can be made of resin, metal, ceramic, wood, or any other material. In the example shown in FIGS. 1 and 2, the bending preventing portion 9 is formed so as to connect the positive electrode current collector 7 and the negative electrode current collector 8.

  As shown in FIGS. 1 and 2, the bending prevention portion 9 is provided outside the seal portion 11 formed between the positive electrode current collector 7 and the negative electrode current collector 8 so as to surround the electrode layer body 3. And

  Thereafter, the unit cell unit 2 on which the bending prevention portion 9 is formed is pressurized along the stacking direction of the electrode layer body 3. Next, the unit cell unit 2 is cut along the plane B set between the bending prevention portion 9 and the seal portion 11, and the bending prevention portion 9, the positive electrode current collector 7 and the negative electrode current collector 8 are separated. Remove the outer edge.

  As described above, the cell unit 2 is provided with the bending prevention unit 9. Before the cell unit 2 is completed, the cell unit 2 is cut along the plane B so as to cut out the inner side of the plane B, thereby preventing the bending unit. By removing 9, a finished product of the unit cell unit 2 is obtained.

  Therefore, as in Patent Document 1, in order to reduce the weight and volume of the secondary battery and prevent the battery energy density from being lowered, the work of peeling the positive electrode current collector and the anti-bending portion bonded to the negative electrode current collector is performed. Is not necessary, and the secondary battery is separated by a simple process of cutting the positive electrode current collector 7 and the negative electrode current collector 8 of the unit cell unit pressurized in the pressurizing process along the stacking direction of the electrode layer body 3. The battery energy density can be prevented from decreasing by reducing the weight and volume of the battery.

  When the unit cell unit 2 is pressurized, a load due to the pressure is applied to the curving prevention unit 9 and the pressure applied to the electrode layer body 3 may be reduced. For this reason, it is preferable that the pressurization range is set inside the curving prevention unit 9. Moreover, in order to prevent the pressure non-uniformity to the electrode layer body 3 from being generated due to the frictional force on the powder constituting the electrode layer body 3, the peripheral edge of the electrode layer body 3 can be strongly pressurized. The shape of the surface of the pressure member is preferably a concave shape.

  In the unit cell unit 2 thus pressed, the bending of the electrode layer body 3 can be suppressed even after being pressed by the bending preventing portion 9 formed on the outer edges of the positive electrode current collector 7 and the negative electrode current collector 8. . By leaving the unit cell unit 2 in this state for several hours, the residual stress inside the powder of the electrode layer body 3 is reduced. For this reason, even after cutting the unit cell unit 2 along the surface B and removing the anti-bending portion 9 from the unit cell unit 2, the electrode layer body 3 of the unit cell unit 2 can be prevented from bending.

  For example, when a laminate of a square current collector having a thickness of about 20 μm and an outer shape of 120 mm on a side and a square electrode layer body 3 having a total thickness of about 200 μm and an outer diameter of 100 mm on a side is pressed, a bending preventing portion When 9 was not provided, the entire electrode layer body 3 was bent by about 10 to 20 mm.

However, the outer shape of the current collector is increased from 120 mm on one side to 160 mm on one side, and a resin (for example, PET (Poly Ethylene Terephthalate, polyethylene, PET) having a width of 20 mm and a thickness of about 200 μm is formed on the outer edge of the current collector. By adhering terephthalate)), the curvature of the electrode layer body 3 could be reduced to about 3 to 4 mm.
(Embodiment 2)
The cell unit 2 similar to that of the first embodiment is provided with the anti-bending portion 9 and pressurized, and then the cell unit 2 is provided with the anti-bending portion 9 in the unit cell unit 2, for example, for about 2 to 10 hours. Was stored (leaved), and then the curvature of the electrode layer body 3 could be maintained at about 3 to 4 mm even if the bending prevention portion 9 was removed from the unit cell unit 2. As shown in FIGS. 1 and 2, the position where the unit cell unit 2 is cut to remove the anti-bending portion 9 needs to be outside the seal portion 11, but may be as close as possible to the electrode layer body 3. preferable.

  The amount of bending of the electrode layer body 3 varies depending on the powder, current collector, and conditions based on the applied pressure used for the electrode layer body 3. For this reason, it is necessary to change the bending prevention part 9 so that it may meet such conditions.

  The curving prevention unit 9 can change at least one of width, shape, thickness, material, and the like so as to meet the above conditions. The shape of the anti-bending portion 9 is, for example, a square shape, a shape formed only on one side of a quadrilateral current collector, a shape formed only on a corner, or two sides It is possible to select whether the shape is formed only on the three sides, the shape formed only on the three sides, or the like.

  However, in the method of the second embodiment, in order to reduce the amount of bending, it is necessary to leave all the cell units 2 manufactured by forming the bending prevention portion 9 for several hours, and then remove the bending prevention portion 9. is there.

(Embodiment 3)
FIG. 3 is a perspective view showing a method for manufacturing the all-solid-state lithium ion secondary battery 1B according to the third embodiment. The all solid lithium ion secondary battery 1 </ b> B includes a laminated battery unit 10 and a package member 12. The stacked battery unit 10 includes a plurality of unit cell units 2 stacked.

  In the third embodiment, the laminated battery unit 10 formed by laminating a plurality of unit cell units 2 having a small curvature created in the first embodiment is sandwiched and held by the package member 12 formed in a U shape. The package member 12 is a temporary package or a product package.

  Then, in a state where the laminated battery unit 10 is sandwiched between the package members 12, the cut portion 13 in which the bending prevention portion 9 is formed is removed by cutting. In this way, the bending preventing portion 9 is removed in a state where the battery unit 2 is physically restrained by the package member 12. For this reason, the curvature of the electrode layer body 3 of the unit cell unit 2 is basically suppressed by the shape and strength of the package member 12.

  In the third embodiment, as shown in FIG. 3, the bending prevention portions 9 are formed only on the three sides of the quadrilateral unit cell unit 2. A plurality of unit cell units 2 each having the anti-bending portion 9 formed on only three sides are stacked. The curving prevention unit 9 has a width of 30 mm and a thickness of 200 μm. In FIG. 3, only three unit cell units 2 are drawn so that the configuration can be easily understood. However, actually, for example, 20 unit cell units 2 are stacked and sandwiched between the package members 12. The shape of the package member 12 is determined so that the gap between the single battery units 2 and the gap between the package member 12 and the single battery unit 2 as illustrated in FIG.

  In the example shown in FIG. 3, the bending prevention portion 9 is formed on three sides of the single battery unit 2 and the package member 12 has a U-shaped shape. However, the present invention is not limited to this. There is no problem as long as the anti-bending portion 9 is formed on two or more sides of the current collector of the single battery unit 2. Moreover, the bending prevention part 9 may be formed continuously along the periphery of the current collector, or may be formed intermittently (in a broken line shape).

When the package member 12 is U-shaped as shown in FIG. 3, a low load of about several g / cm ² to several hundred g / cm ² along the stacking direction of the unit cell unit 2 indicated by the arrow 14. Is added to the package member 12, and the bend preventing portion 9 is removed by cutting. Then, processing such as connection of the electrode extraction unit to the current collector is performed. Thereafter, the U-shaped package member 12 is combined with other U-shaped package members so as to form a hexahedron. Next, the package member 12 and another package member are connected by laser welding or the like, thereby completing the package of the all fixed battery.

  In FIG. 3, an example in which the package member 12 is U-shaped has been described, but the present invention is not limited to this. The shape of the package member 12 may be any shape as long as it can finally seal the laminated battery unit 10.

  After the stacked battery unit 10 is sealed by the package member 12 and another package member, the bending of the unit cell unit 2 is suppressed by the rigidity of the package member 12 and the other package member. For this reason, the low load applied to the package member 12 may be removed after the laminated battery unit 10 is sealed.

  The cutting method for removing the curving prevention unit 9 described in the first to third embodiments is not limited to a specific cutting method. For the cutting method, punching, laser cutting, other cutting, or the like can be applied.

(Embodiment 4)
In the first to third embodiments described above, an example in which the bending prevention portion 9 is formed so as to connect the positive electrode current collector 7 and the negative electrode current collector 8 has been described. However, the present invention is not limited to this. The bending prevention portion 9 may be formed by bending at least one outer edge of the positive electrode current collector 7 and the negative electrode current collector 8.

  FIG. 4 is a cross-sectional view showing a bending prevention portion 9A provided in the single battery unit 2. As shown in FIG. In the example shown in FIG. 4, the outer edge of the positive electrode current collector 7 is bent toward the negative electrode current collector 8, thereby forming the bending preventing portion 9 </ b> A. In addition, the frequency | count of bending may not be 1 time. For example, the anti-bending part 9A obtained by bending the outer edge of the positive electrode current collector 7 may be further bent. Thereby, the strength of the positive electrode current collector 7 is improved. For this reason, the curvature of the electrode layer body 3 is further suppressed. The bending preventing portion 9A may be formed by bending the outer edge of the negative electrode current collector 8 toward the positive electrode current collector 7 side.

  As described above, Embodiments 1 to 4 are methods for manufacturing all solid lithium ion secondary batteries 1, 1 A, and 1 B in which the solid electrolyte layer 5 is disposed between the positive electrode layer 4 and the negative electrode layer 6. Includes a molding process. A current collector having a larger area than the electrode layer including the positive electrode layer 4 and the negative electrode layer 6 is formed. By forming the bending preventing portions 9 and 9A on the outer edge of the current collector, the bending of the electrode layer after the pressure forming step is suppressed. Next, in the subsequent process, the curving prevention portions 9 and 9A formed on the outer edge of the current collector are removed by cutting, and the product of the all-solid battery is completed. The bending preventing portions 9 and 9A are formed on at least one outer edge of the positive electrode current collector 7 and the negative electrode current collector 8.

  The removal of the curving prevention portions 9 and 9A by cutting is performed after a certain time has elapsed since the pressure molding of the unit cell unit 2, or the stacked battery unit 10 in which a plurality of unit cell units 2 after the pressure molding are stacked is stacked. It is preferable that the stacked battery unit 10 be sandwiched between package members 12 that can be held.

  By using the first to fourth embodiments described above, in particular, when manufacturing the all-solid lithium ion secondary batteries 1, 1 A, 1 B in which the shape of the laminated electrode layer body 3 is flat, the positive electrode layer 4, The positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode layer 6 can be laminated in a state where the curvature of the solid electrolyte layer 5 and the negative electrode layer 6 is suppressed. For this reason, the all-solid-state lithium ion secondary battery 1 * 1A * 1B whose energy density is high and curving was suppressed can be manufactured.

(Summary)
As described above, the manufacturing method of the all solid state batteries (all solid state lithium ion secondary batteries 1 and 1A) according to Embodiments 1 and 4 includes the positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode layer 6. The electrode layer body 3 laminated so that the solid electrolyte layer 5 is disposed between the anode layer 6 and the electrode layer body 3 disposed on the opposite side of the positive electrode layer 4 from the solid electrolyte layer 5. A single battery unit 2 including a positive electrode current collector 7 having a large area and a negative electrode current collector 8 disposed on the opposite side of the negative electrode layer 6 from the solid electrolyte layer 5 and having a larger area than the electrode layer body 3. Including the forming step, and the step of forming the unit cell unit 2 includes the anti-curvature portions 9 and 9A for preventing the electrode layer body 3 from bending, at least of the positive electrode current collector 7 and the negative electrode current collector 8. Bending prevention part forming process formed on one outer edge and bending by the bending preventing part forming process And a pressurizing step of pressurizing along a single cell unit 2 to stop unit 9 · 9A is formed in the stacking direction of the electrode layer body 3.

  According to this configuration, the position where the anti-bending portions 9, 9 A for preventing the electrode layer body 3 from bending is the outer edge of at least one of the positive electrode current collector 7 and the negative electrode current collector 8. . Therefore, in order to reduce the weight and volume of the completed secondary battery and prevent the battery energy density from being lowered, the anti-curvature portion bonded to the surface of the positive electrode current collector opposite to the positive electrode layer, and the negative electrode It is easier to remove the anti-bending portion than the prior art that requires the work of peeling off the anti-bending portion adhered to the surface of the current collector opposite to the negative electrode layer. Therefore, while reducing the curvature of the electrode layer body, the weight and volume of the completed all-solid battery can be easily reduced to easily prevent the battery energy density from being lowered.

  In the manufacturing method of the all-solid battery (all-solid lithium ion secondary battery 1B) according to Embodiment 3, the positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode layer 6 are solid between the positive electrode layer 4 and the negative electrode layer 6. The electrode layer body 3 laminated so that the electrolyte layer 5 is disposed, and the positive electrode current collector 7 disposed on the opposite side of the positive electrode layer 4 from the solid electrolyte layer 5 and having a larger area than the electrode layer body 3. A plurality of unit cell units 2 including a plurality of unit cell units 2 disposed on the opposite side of the negative electrode layer 6 from the solid electrolyte layer 5 and having a larger area than the electrode layer body 3. Including a forming step, wherein the step of forming a plurality of unit cell units prevents the electrode layer body 3 from bending, the bending preventing portions 9 and 9A, the positive electrode current collectors 7 of the plurality of unit cell units 2 and the Formation of a curving prevention portion formed on at least one outer edge of the negative electrode current collector 8 The stacking step of forming the stacked battery unit 10 in which the plurality of unit cell units 2 are stacked, and the stacked battery unit 10 stacked in the stacking step are pressurized along the stacking direction of the electrode layer body 3. Pressurizing step.

  According to this configuration, the position where the anti-bending portions 9, 9 A for preventing the electrode layer body 3 from bending is the outer edge of at least one of the positive electrode current collector 7 and the negative electrode current collector 8. . Therefore, in order to reduce the weight and volume of the completed secondary battery and prevent the battery energy density from being lowered, the anti-curvature portion bonded to the surface of the positive electrode current collector opposite to the positive electrode layer, and the negative electrode It is easier to remove the anti-bending portion than the prior art that requires the work of peeling off the anti-bending portion adhered to the surface of the current collector opposite to the negative electrode layer. Therefore, while reducing the curvature of the electrode layer body, the weight and volume of the completed all-solid battery can be easily reduced to easily prevent the battery energy density from being lowered.

  In the all-solid-state battery manufacturing method, at least one of the positive electrode current collector 7 and the negative electrode current collector 8 of the single battery unit 2 or the stacked battery unit 10 pressurized in the pressurizing step is used as the electrode layer body. 3 may further include a removing step of removing the anti-bending portions 9 and 9A by cutting along the stacking direction 3.

  According to this configuration, the bending prevention portion can be removed with a simple configuration of cutting along the stacking direction of the electrode layer body.

  In the manufacturing method of the all-solid-state battery, in order to reduce the residual stress generated in the electrode layer body 3 of the single battery unit 2 or the laminated battery unit 10 pressurized in the pressurizing step, the single battery unit 2 Alternatively, after the stacked battery unit 10 is allowed to stand for a predetermined time, the bending preventing portions 9 and 9A may be removed.

  According to this configuration, since the residual stress generated inside the electrode layer body 3 is reduced, the curvature of the electrode layer body 3 can be further reduced.

  In the all-solid-state battery manufacturing method, the positive electrode current collector 7 and the negative electrode current collector 8 have a quadrilateral shape when viewed from the stacking direction, and the positive electrode current collector 7 and the negative electrode current collector are The bend preventing portion 9 may be formed on at least two sides of at least one of 8.

  According to this configuration, since the bending preventing portion is formed on at least two sides of the quadrilateral, the bending of the electrode layer body 3 can be effectively reduced.

  In the manufacturing method of the all-solid-state battery, the curving prevention portions 9 and 9A are formed so as to connect the positive electrode current collector 7 and the negative electrode current collector 8, or the positive electrode current collector 7 and the negative electrode The bending preventing portion 9 may be formed by bending at least one outer edge of the current collector 8.

  According to this structure, in order to prevent the electrode layer body 3 from bending, the bending preventing portions 9 and 9A disposed on the outer edge of at least one of the positive electrode current collector 7 and the negative electrode current collector 8 are simply configured. Can be formed.

  In the all solid state battery manufacturing method, the surface roughness of at least one of the positive electrode current collector 7 and the negative electrode current collector 8 may be Rz = 1.0 μm or more.

  According to this structure, the curvature which generate | occur | produces in the electrode layer body 3 by at least one of the said positive electrode collector 7 and the said negative electrode collector 8 with large surface roughness can be reduced.

  In the all solid state batteries (all solid state lithium ion secondary batteries 1, 1 A, 1 B) according to the first to third embodiments, the positive electrode layer 4, the solid electrolyte layer 5, and the negative electrode layer 6 include the positive electrode layer 4 and the negative electrode layer 6. The electrode layer body 3 laminated so that the solid electrolyte layer 5 is disposed therebetween, and the positive electrode assembly disposed on the opposite side of the positive electrode layer 4 from the solid electrolyte layer 5 and having a larger area than the electrode layer body 3 In order to prevent bending of the electrode layer body 3, the negative electrode current collector 8, the negative electrode current collector 8 disposed on the opposite side of the negative electrode layer 6 from the solid electrolyte layer 5 and having a larger area than the electrode layer body 3. In addition, an anti-bending portion 9, 9 A formed on at least one outer edge of the positive electrode current collector 7 and the negative electrode current collector 8 is provided.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

1 ・ 1A ・ 1B All-solid-state lithium ion secondary battery (all-solid-state battery)
2 unit cell unit 3 electrode layer body 4 positive electrode layer 5 solid electrolyte layer 6 negative electrode layer 7 positive electrode current collector 8 negative electrode current collector 9.

Claims (8)

An electrode layer body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked such that the solid electrolyte layer is disposed between the positive electrode layer and the negative electrode layer; and the solid electrolyte layer of the positive electrode layer; A positive electrode current collector that is disposed on the opposite side and has a larger area than the electrode layer body; and a negative electrode current collector that is disposed on the opposite side of the negative electrode layer from the solid electrolyte layer and has a larger area than the electrode layer body; Including a step of forming a unit cell unit including:
The step of forming the unit cell unit includes
A curving prevention part forming step for forming a curving prevention part for preventing curving of the electrode layer body on at least one outer edge of the positive electrode current collector and the negative electrode current collector;
And a pressurizing step of pressurizing the unit cell unit in which the anti-curvature portion is formed by the anti-bend portion forming step along the stacking direction of the electrode layer body. An electrode layer body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked such that the solid electrolyte layer is disposed between the positive electrode layer and the negative electrode layer; and the solid electrolyte layer of the positive electrode layer; A positive electrode current collector that is disposed on the opposite side and has a larger area than the electrode layer body; and a negative electrode current collector that is disposed on the opposite side of the negative electrode layer from the solid electrolyte layer and has a larger area than the electrode layer body; Including a plurality of unit cell unit forming steps for forming a plurality of unit cell units including:
The unit cell unit forming step includes:
An anti-bending part forming step for forming an anti-bending part for preventing the electrode layer body from bending on at least one outer edge of the positive electrode current collector and the negative electrode current collector of the plurality of unit cell units;
A stacking step of forming a stacked battery unit in which the plurality of unit cell units are stacked;
And a pressurizing step of pressurizing the laminated battery unit laminated in the laminating step along the laminating direction of the electrode layer body. Preventing the bending by cutting at least one of the positive electrode current collector and the negative electrode current collector of the unit cell unit or the stacked battery unit pressed in the pressing step along the stacking direction of the electrode layer body. The method for producing an all solid state battery according to claim 1, further comprising a removing step of removing the portion.   After the unit cell unit or the laminated battery unit is left for a predetermined time in order to reduce the residual stress generated in the electrode layer body of the unit cell unit or the laminated battery unit pressurized by the pressurization step, The method for manufacturing an all-solid-state battery according to any one of claims 1 to 3, wherein the bending prevention portion is removed. The positive electrode current collector and the negative electrode current collector have a quadrilateral shape when viewed from the stacking direction;
5. The all-solid-state battery production according to claim 1, wherein the bending prevention portion is formed on at least two sides of at least one of the positive electrode current collector and the negative electrode current collector. Method.   The curving prevention part is formed so as to connect the positive electrode current collector and the negative electrode current collector, or the bending is performed by bending an outer edge of at least one of the positive electrode current collector and the negative electrode current collector. The prevention part is formed, The manufacturing method of the all-solid-state battery as described in any one of Claim 1 to 5 characterized by the above-mentioned.   7. The all-solid-state battery according to claim 1, wherein the surface roughness of at least one of the positive electrode current collector and the negative electrode current collector is Rz = 1.0 μm or more. Manufacturing method. An electrode layer body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked such that the solid electrolyte layer is disposed between the positive electrode layer and the negative electrode layer;
A positive electrode current collector disposed on the side of the positive electrode layer opposite to the solid electrolyte layer and having a larger area than the electrode layer body;
A negative electrode current collector disposed on a side opposite to the solid electrolyte layer of the negative electrode layer, and having a larger area than the electrode layer body;
An all-solid-state battery comprising: a bend preventing portion formed at an outer edge of at least one of the positive electrode current collector and the negative electrode current collector in order to prevent the electrode layer body from being bent.

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