Battery manufacturing device

Abstract

To provide a battery manufacturing device that can improve battery quality and ultimately contribute to energy efficiency.SOLUTION: A battery manufacturing device includes: a pressing unit 31 that comes into contact with an electrode stack 2 in a state of a stack of positive electrode layers 6, 7, negative electrode layers 8, 9, and solid electrolyte layers 11, 12, from the outside in a stacking direction of the electrode stack 2; a plurality of load input units 32 that apply a load to the pressing unit 31 so as to compress the electrode stack 2 in the stacking direction; and a buffer material 34 that fills gaps between the positive electrode layers 6, 7 and the negative electrode layers 8, 9. The plurality of load input units 32 are arranged in a direction perpendicular to the stacking direction of the electrode stack 2, and includes a pressure control unit 33 that individually controls the loads applied to the pressing unit 31 by the plurality of load input units 32.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a battery manufacturing apparatus. [Background technology]

[0002] In recent years, efforts to provide access to sustainable transportation systems have been gaining momentum. Toward this goal, development of all-solid-state batteries, for example, is underway. An all-solid-state battery comprises a positive electrode layer, a negative electrode layer disposed opposite the positive electrode layer in the thickness direction, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer. These positive electrode layer, negative electrode layer, and solid electrolyte layer are stacked and pressurized in the stacking direction. This allows sufficient bonding at the interface between the positive electrode layer and the solid electrolyte layer, and at the interface between the negative electrode layer and the solid electrolyte layer, enabling the battery to operate (see, for example, Patent Document 1).

[0003] When pressurizing an all-solid-state battery, there are cases where the entire surface of the all-solid-state battery cannot be pressed with a uniform force. In such cases, the bonding at the interfaces between the solid electrolyte layer and each electrode layer becomes partially insufficient, resulting in a decrease in battery performance. For this reason, a manufacturing device that can uniformly distribute the pressure across the entire surface of the all-solid-state battery has been proposed (see, for example, Patent Document 2). This device includes multiple pressure cylinders that press the all-solid-state battery in the stacking direction and a pressure control device that individually controls the pressure of each pressure cylinder. By individually controlling the pressure of each pressure cylinder, the entire surface of the all-solid-state battery can be pressed with a uniform force. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6943208 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-142042 Summary of the Invention [Problem to be solved by the invention]

[0005] In an all-solid-state battery, the area of ​​the positive electrode layer and the area of ​​the negative electrode layer may be different. For example, the area of ​​the negative electrode layer is made larger than the area of ​​the positive electrode layer. This configuration prevents the positive electrode layer and the negative electrode layer from short-circuiting due to expansion or contraction of the active material when the all-solid-state battery is operated.

[0006] In this configuration, a gap occurs between the positive electrode layer and the negative electrode layer. Therefore, when compressing an all-solid-state battery, the positive electrode layer may not be able to fully withstand the pressure applied to the entire surface of the negative electrode layer, resulting in localized stress being applied to a portion of the negative electrode layer. In this case, there is a problem that the negative electrode layer may be damaged, resulting in a decrease in battery quality.

[0007] Therefore, the present invention provides a battery manufacturing apparatus that can improve the quality of batteries and ultimately contribute to energy efficiency. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following means. (1) A battery manufacturing apparatus according to the present invention (e.g., the battery manufacturing apparatus 30 of the embodiments) is a battery manufacturing apparatus that applies pressure to an electrode stack (e.g., the electrode stack 2 of the embodiments) that includes a positive electrode layer (e.g., the first positive electrode layer 6 and the second positive electrode layer 7 of the embodiments), a negative electrode layer (e.g., the first negative electrode layer 8 and the second negative electrode layer 9 of the embodiments) that is disposed opposite to the positive electrode layer in the thickness direction and has an area different from that of the positive electrode layer, and a solid electrolyte layer (e.g., the first solid electrolyte layer 11 and the second solid electrolyte layer 12 of the embodiments) that is disposed between the positive electrode layer and the negative electrode layer, and that applies pressure to an electrode stack (e.g., the electrode stack 2 of the embodiments) that includes a state in which the positive electrode layer, the negative electrode layer, and the solid electrolyte layer are stacked together. The electrode stack is provided with a pressing portion (e.g., pressing portion 31 in the embodiment) that contacts the electrode stack from the outside in the stacking direction of the electrode stack, a plurality of load input portions (e.g., load input portion 32 in the embodiment) that apply a load to the pressing portion so as to compress the electrode stack in the stacking direction, and a buffer material (e.g., buffer material 34 in the embodiment) that fills the gap between the positive electrode layer and the negative electrode layer, the plurality of load input portions being arranged along a direction perpendicular to the stacking direction of the electrode stack, and a pressure control portion (e.g., pressure control portion 33 in the embodiment) that individually controls the load applied to the pressing portion by the plurality of load input portions.

[0009] In this way, by controlling the loads applied to the pressing units by the multiple load input units using the pressure control unit, the entire surface of the electrode stack can be pressed with a uniform force. When pressing the electrode stack, part of the pressing force can be reliably received by the buffer material. This prevents localized stress from being applied to the electrode stack, while reliably bonding the interfaces between the solid electrolyte layer and each electrode layer. This improves the quality of the battery.

[0010] (2) In the above configuration, the buffer material may include a first buffer portion (e.g., first buffer portion 43 in the embodiment) arranged within the range in which the electrode stack is arranged when viewed from the stacking direction of the electrode stack, and a second buffer portion (e.g., second buffer portion 44 in the embodiment) covering the outermost periphery of the electrode stack.

[0011] By configuring in this manner, deformation of the electrode stack can be more reliably suppressed, and the quality of the battery can be improved.

[0012] (3) In the above configuration, the first buffer section and the second buffer section may have different physical properties.

[0013] This configuration allows buffer materials with the necessary physical properties to be placed depending on the location where the buffer materials are placed, thereby efficiently suppressing deformation of the electrode stack.

[0014] (4) In the above configuration, the first buffer portion may have physical properties similar to those of the electrode stack, and the second buffer portion may have physical properties similar to those of a current collector drawn from the electrode stack.

[0015] By configuring in this way, deformation of each part can be more effectively suppressed. [Effects of the Invention]

[0016] According to the present invention, the quality of the battery can be improved, which in turn can contribute to energy efficiency. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view showing an outline of an all-solid-state battery according to an embodiment of the present invention. [Figure 2] 1 is a diagram showing an outline of a battery manufacturing apparatus according to an embodiment of the present invention, and an exploded view of an all-solid-state battery; [Figure 3] 10 is an explanatory diagram showing a state in which the electrode stack is compressed in the stacking direction by a load input unit and a pressure control unit according to the embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Next, an embodiment of the present invention will be described with reference to the drawings.

[0019] <All-solid-state battery> Fig. 1 is a cross-sectional view showing an outline of an all-solid-state battery 1. In Fig. 1, the scale of each part has been changed appropriately to make the explanation easier to understand. As shown in FIG. 1, the all-solid-state battery 1 includes an electrode laminate 2, an exterior body 3 that covers the electrode laminate 2, and two lead tabs 4, 5 (a positive electrode lead tab 4 and a negative electrode lead tab 5) that are drawn out from the electrode laminate 2 via the exterior body 3.

[0020] <Electrode laminate> The electrode stack 2 is formed into a rectangular parallelepiped shape as a whole. The electrode stack 2 mainly comprises two plate-shaped positive electrode layers 6, 7 (first positive electrode layer 6, second positive electrode layer 7), two negative electrode layers 8, 9 (first negative electrode layer 8, second negative electrode layer 9) arranged opposite the positive electrode layers 6, 7 in the thickness direction, and solid electrolyte layers 11, 12 (first solid electrolyte layer 11, second solid electrolyte layer 12) arranged between the positive electrode layers 6, 7 and the negative electrode layers 8, 9, respectively.

[0021] The two positive electrode layers 6, 7 each have a positive electrode active material layer 13. The two positive electrode layers 6, 7 have a common positive electrode current collector 14. The positive electrode active material layers 13 are laminated on both sides of the positive electrode current collector 14. Examples of active materials that constitute the positive electrode active material layers 13 include lithium cobalt oxide, lithium nickel oxide, lithium manganate, lithium metal phosphate, lithium nickel cobalt manganate, and lithium nickel cobalt aluminate.

[0022] The positive electrode current collector 14 is drawn out from the positive electrode active material layers 13 in a direction perpendicular to the stacking direction of these positive electrode active material layers 13 (hereinafter, the direction perpendicular to the stacking direction may be referred to as the planar direction). The positive electrode current collector 14 is formed of a metal foil, a metal sheet, or a metal plate made of, for example, aluminum, copper, stainless steel, or the like.

[0023] The first negative electrode layer 8 of the two negative electrode layers 8, 9 is disposed opposite the first positive electrode layer 6 of the two positive electrode layers 6, 7 in the thickness direction. The second negative electrode layer 9 of the two negative electrode layers 8, 9 is disposed opposite the second positive electrode layer 7 of the two positive electrode layers 6, 7 in the thickness direction. More specifically, the first negative electrode layer 8 is disposed on the side of the first positive electrode layer 6 opposite the second positive electrode layer 7. The second negative electrode layer 9 is disposed on the side of the second positive electrode layer 7 opposite the first positive electrode layer 6.

[0024] The two negative electrode layers 8, 9 each have a negative electrode active material layer 15. The area of ​​the negative electrode active material layer 15 is larger than the area of ​​the positive electrode active material layer 13. Therefore, the negative electrode active material layer 15 protrudes in the planar direction more than the positive electrode active material layer 13. As a result, a gap G is formed between the two negative electrode layers 8, 9 at the outer peripheries of the two negative electrode layers 8, 9. This gap G can also be said to be formed at the outer peripheries of the two positive electrode layers 6, 7. In other words, the gap G is formed between the positive electrode layers 6, 7 and the negative electrode layers 8, 9.

[0025] Examples of the active material constituting the negative electrode active material layer 15 include lithium-based materials and silicon-based materials. Examples of the lithium-based materials include Li metal and Li alloys. Examples of the silicon-based materials include Si and SiO. Other examples of the active material constituting the negative electrode active material layer 15 include carbon materials such as graphite, soft carbon, and hard carbon, tin-based materials (Sn, SnO, etc.), and lithium titanate.

[0026] A negative electrode current collector 16 is laminated on the opposite side of each negative electrode active material layer 15 from the positive electrode layers 6, 7. The negative electrode current collector 16 is formed of the same material as the positive electrode current collector 14. Each negative electrode current collector 16 is pulled out in the planar direction from the corresponding negative electrode active material layer 15. For example, this pulling direction is opposite to the pulling direction of the positive electrode current collector 14. A tip end 16a of each negative electrode current collector 16 in the pulling direction is bent toward the center of the electrode stack 2 in the stacking direction.

[0027] Of the solid electrolyte layers 11, 12, the first solid electrolyte layer 11 is disposed between the first positive electrode layer 6 and the first negative electrode layer 8. Of the solid electrolyte layers 11, 12, the second solid electrolyte layer 12 is disposed between the second positive electrode layer 7 and the second negative electrode layer 9. The area of ​​each of the solid electrolyte layers 11, 12 is equal to the area of ​​the negative electrode active material layer 15. Each of the solid electrolyte layers 11 and 12 is formed of, for example, a solid electrolyte having ion conductivity. Examples of the material of the solid electrolyte layers 11 and 12 include a sulfide-based solid electrolyte material, an oxide-based solid electrolyte material, a nitride-based solid electrolyte material, and a halide-based solid electrolyte material.

[0028] The solid electrolyte layers 11 and 12, the positive electrode active material layer 13, and the negative electrode active material layer 15 may be formed by binding particles of the materials that make them up with an organic polymer compound binder.

[0029] The exterior body 3 is formed, for example, by folding the laminate film 21 that forms this exterior body 3 in half. The laminate film 21 is formed, for example, by covering the front and back surfaces of a metal layer with a resin layer (insulating layer). Such an exterior body 3 has flexibility that can follow the expansion and contraction of the electrode stack 2. The flexibility that can follow the expansion and contraction of the electrode stack 2 can be obtained by the way in which the exterior body 3 wraps around the electrode stack 2, the shape, the structure, etc.

[0030] Of the two lead tabs 4, 5, one end of the positive electrode lead tab 4 is connected to the tip portion 14a of the positive electrode current collector 14. The positive electrode lead tab 4 extends in the surface direction of the electrode laminate 2. The other end of the positive electrode lead tab 4 is drawn out to the outside of the exterior body 3 via the exterior body 3. Of the two lead tabs 4, 5, one end of the negative electrode lead tab 5 is connected to a tip portion 16a of a negative electrode current collector 16 on each of both sides. The negative electrode lead tab 5 extends in the surface direction of the electrode laminate 2. The extending direction of the negative electrode lead tab 5 is, for example, opposite to the extending direction of the positive electrode lead tab 4. The other end of the negative electrode lead tab 5 is drawn out to the outside of the exterior body 3 via the exterior body 3.

[0031] The two lead tabs 4 and 5 are formed, for example, from a conductive metal sheet or plate. Such an all-solid-state battery 1 is connected to a charger or an electrical load via two lead tabs 4, 5, thereby charging or discharging the electrode stack 2.

[0032] <Battery manufacturing equipment> Next, a battery manufacturing apparatus 30 for manufacturing the all-solid-state battery 1 will be described with reference to FIG. 2 is a diagram showing an outline of a battery manufacturing apparatus 30 and an exploded view of an all-solid-state battery 1. In FIG. 2, the scale of each part has been appropriately changed to make the explanation easier to understand. In the following explanation, in the electrode stack 2, the outside on the side opposite to the center in the stacking direction will be simply referred to as the outside in the stacking direction or both sides in the stacking direction.

[0033] As shown in FIG. 2, the battery manufacturing apparatus 30 includes pressing sections 31 arranged on both sides of the electrode stack 2 in the stacking direction, a plurality of load input sections 32 that press the pressing sections 31, a pressure control section 33 that controls the load of each load input section 32 on the pressing sections 31, and a buffer material 34 arranged to fill the gap G between the positive electrode layers 6, 7 and the negative electrode layers 8, 9.

[0034] The pressing portion 31 is a thin plate-like member that is elastically deformable. The multiple load input portions 32 are arranged on one of the two pressing portions 31 (the upper one in FIG. 2 ). The multiple load input portions 32 are arranged side by side at equal intervals in the surface direction of the electrode stack 2. Each load input portion 32 includes a rod body 35 extending in the stacking direction of the electrode stack 2, and a flange portion 36 provided at the end of the rod body 35 on the pressing portion 31 side. The multiple load input portions 32 press the flange portion 36 against the pressing portion 31. The multiple load input portions 32 press the electrode stack 2 via the pressing portion 31 so as to compress it in the stacking direction.

[0035] The pressure control unit 33 includes a control unit main body 37 that applies a pressing force to each load input unit 32 against the pressing unit 31, and a plurality of control springs 38 that are attached to each load input unit 32 from the side opposite the pressing unit 31. The control spring 38 is made of a material, such as ceramics, that is extremely resistant to plastic deformation and is also elastically deformable. The control unit main body 37 applies a pressing force to each load input unit 32 against the pressing unit 31 via the control spring 38. This pressing force can be applied by various methods such as air pressure or hydraulic pressure.

[0036] The buffer material 34 includes a first buffer material 41 arranged on the side of the first positive electrode layer 6 and the first negative electrode layer 8, and a second buffer material 42 arranged on the side of the second positive electrode layer 7 and the second negative electrode layer 9. Each of the buffer materials 41, 42 is made of an elastically deformable material, and receives a load from the load input portion 32 during the manufacture of the electrode stack 2 (details will be described later). These buffer materials 41 and 42 are provided symmetrically about the center in the stacking direction of the electrode stack 2. For this reason, in the following explanation, only the first buffer material 41 will be explained. The second buffer material 42 will be given the same reference numeral as the first buffer material 41 and its explanation will be omitted. The second buffer material 42 will be explained as necessary.

[0037] The first buffer material 41 is integrally formed with a first buffer section 43 disposed in the gap G between the first positive electrode layer 6 and the first negative electrode layer 8, and a second buffer section 44 disposed on an outer surface 43a of the first buffer section 43 in the plane direction of the electrode stack 2. The first buffer material 41 is formed in an L-shape in cross section in the stacking direction of the electrode stack 2. More specifically, when viewed from the stacking direction of the electrode stack 2, the first buffer portion 43 of the first buffer material 41 is disposed within the range in which the electrode stack 2 is disposed. The thickness T1 of the first buffer portion 43 in the stacking direction is equal to the thickness T2 of the first positive electrode layer 6 in the stacking direction.

[0038] The second buffer section 44 extends outward in the stacking direction of the electrode stack 2 from the outer surface 43a of the first buffer section 43. A portion of the outer end surface 44a in the stacking direction of the second buffer section 44 is in contact with the negative electrode current collector 16. That is, of the thickness of the second buffer section 44 in the stacking direction, a thickness T3 between the outer end surface 43b in the stacking direction of the first buffer section 43 and the outer end surface 44a of the second buffer section 44 is equivalent to a thickness T4 obtained by adding the thickness of the first solid electrolyte layer 11 and the thickness of the first negative electrode layer 8 in the stacking direction.

[0039] It is more preferable to partially consider the thickness of the positive electrode current collector 14 and the thickness of the negative electrode current collector 16 when determining the thicknesses T1 and T4 of the buffer portions 43 and 44. However, the buffer portions 43 and 44 elastically deform. When considering the elastic deformation of the buffer portions 43 and 44, the thicknesses of the positive electrode current collector 14 and the negative electrode current collector 16 are negligible. Therefore, when determining the thicknesses T1 and T4 of the buffer portions 43 and 44, it is not necessary to consider the thickness of the positive electrode current collector 14 and the thickness of the negative electrode current collector 16.

[0040] The second buffer section 44 covers the outer surface 43a of the first buffer section 43, the outer surface 8a in the planar direction of the first negative electrode layer 8 (negative electrode active material layer 15), and the outer surface 11a in the planar direction of the first solid electrolyte layer 11. Since the area of ​​the negative electrode active material layer 15 is larger than the area of ​​the positive electrode active material layer 13, the second buffer section 44 covers the outermost periphery of the electrode stack 2.

[0041] The first buffer section 43 and the second buffer section 44 are formed from a material capable of absorbing the load from the load input section 32. The first buffer section 43 and the second buffer section 44 have different physical properties. The physical properties mainly refer to electrical, mechanical, optical, thermal, magnetic, and other properties. The first buffer section 43 and the second buffer section 44 differ, for example, in the linear expansion coefficient, Young's modulus, hardness, and the like.

[0042] The physical properties of the first buffer section 43 are similar to those of the electrode stack 2. The physical properties of the second buffer section 44 are similar to those of the negative electrode current collector 16. For example, the linear expansion coefficient of the first buffer section 43 is set to 20 to 50 ppm. This is similar to those of the first positive electrode layer 6, the first negative electrode layer 8, and the first solid electrolyte layer 11. In addition, the density of the first buffer section 43 is set to 15 g / cm so as to be similar to the physical properties of the first positive electrode layer 6, the first negative electrode layer 8, and the first solid electrolyte layer 11. 3 or a Poisson's ratio of 0.4 or less.

[0043] For example, the linear expansion coefficient of the second buffer section 44 is larger than the linear expansion coefficient of the first buffer section 43. This is because the physical properties of the second buffer section 44 are similar to the physical properties of the negative electrode current collector 16. The negative electrode current collector 16 is formed of a metal foil, metal sheet, or metal plate made of, for example, aluminum, copper, stainless steel, or the like, and therefore, for example, the elastic region of these and the elastic region of the second buffer section 44 are made similar to each other.

[0044] <Method of manufacturing electrode current collector> Next, a method for manufacturing the electrode stack 2 using the battery manufacturing apparatus 30 will be described with reference to FIGS. First, the electrode laminate 2 is provisionally formed before using the battery manufacturing apparatus 30. That is, first, the positive electrode active material layers 13 are laminated on both sides of the positive electrode current collector 14, respectively, to form the first positive electrode layer 6 and the second positive electrode layer 7.

[0045] Next, the first solid electrolyte layer 11 and the second solid electrolyte layer 12 are formed on the outer sides of each positive electrode active material layer 13 in the stacking direction. Next, the negative electrode active material layers 15 are laminated on the outer sides of the solid electrolyte layers 11 and 12 in the lamination direction, to form the first negative electrode layer 8 and the second negative electrode layer 9. Next, negative electrode current collectors 16 are laminated on the outer sides of the negative electrode active material layers 15 in the lamination direction.

[0046] Thereafter, pressing portions 31 are set on both sides of the electrode stack 2 in the stacking direction, and cushioning materials 41 and 42 are set. One of the two pressing portions 31 is then pressed by the load input portion 32. The other of the two pressing portions 31 is pressed by, for example, a stand or the like.

[0047] The load input unit 32 applies a pressing force to the pressing unit 31 by the pressure control unit 33. As a result, the electrode stack 2 is compressed in the stacking direction. At this time, a reaction force is generated in each load input portion 32 by pressing the pressing portion 31. This causes slight elastic deformation of each control spring 38 of each load input portion 32. This allows the load on the pressing portion 31 by each load input portion 32 to be individually controlled, and the load distribution by each load input portion 32 on the pressing portion 31 becomes uniform.

[0048] The control unit main body 37 of the pressure control unit 33 may individually control the loads applied to the pressing unit 31 by the load input units 32. In this case, the control unit main body 37 may be provided with, for example, a sensor that detects the loads applied to the load input units 32. Based on the detection results of this sensor, the loads applied to the pressing unit 31 by the load input units 32 are individually controlled. This makes it possible to evenly distribute the loads applied to the pressing unit 31 by the load input units 32. Even in this case, the load can be dispersed by the control spring 38. As a result, it is possible to more effectively evenly distribute the loads applied to the pressing unit 31 by the load input units 32.

[0049] 3 is an explanatory diagram showing a state in which the electrode stack 2 is compressed in the stacking direction by the load input unit 32 and the pressure control unit 33. FIG. 3 corresponds to the above-mentioned FIG. As shown in FIG. 3, when the electrode stack 2 is compressed in the stacking direction, the buffer materials 41 and 42 butt against each other in the stacking direction.

[0050] Here, the first buffer portion 43 of each buffer material 41, 42 is disposed in the gap G between the first positive electrode layer 6 and the first negative electrode layer 8. Therefore, the first buffer portion 43 receives the load of the load input portion 32 applied to the outer peripheries of the negative electrode layers 8, 9 and the solid electrolyte layers 11, 12 located above this gap G. In addition, the second buffer portion 44 receives the load of the load input portion 32 applied to the negative electrode current collectors 16.

[0051] When the electrode stack 2 receives a compressive load from the load input unit 32 and the pressure control unit 33, it tends to elongate and deform. Here, the physical properties of the first buffer unit 43 are similar to the physical properties of the electrode stack 2. The physical properties of the second buffer unit 44 are similar to the physical properties of the negative electrode current collector 16. Therefore, the buffer materials 41, 42 suppress excessive elongation and deformation of each part of the electrode stack 2. With the expansion and deformation of the electrode stack 2 suppressed by the buffer materials 41 and 42, the interfaces of the positive electrode layers 6 and 7, the negative electrode layers 8 and 9, and the solid electrolyte layers 11 and 12 are reliably bonded together by the compressive load applied to the electrode stack 2. This completes the manufacture of the electrode stack 2.

[0052] As described above, the battery manufacturing apparatus 30 includes a pressing unit 31, multiple load input units 32, buffer materials 41 and 42, and a pressure control unit 33. The pressure control unit 33 controls the loads applied to the pressing unit 31 by the multiple load input units 32, thereby applying a uniform pressure to the entire surface of the electrode stack 2. When the electrode stack 2 is pressed, a portion of the pressure can be reliably received by the buffer materials 41 and 42. This prevents localized stress from being applied to the electrode stack 2, while reliably bonding the interfaces of the positive electrode layers 6 and 7, the negative electrode layers 8 and 9, and the solid electrolyte layers 11 and 12. This prevents damage to the electrode stack 2 and improves the quality of the all-solid-state battery 1, which ultimately contributes to energy efficiency.

[0053] Each of the buffer materials 41, 42 has a first buffer portion 43 and a second buffer portion 44. Therefore, deformation of the electrode stack 2 can be more reliably suppressed, and the quality of the all-solid-state battery 1 can be improved. The first buffer section 43 and the second buffer section 44 have different physical properties. Therefore, the buffer sections 43, 44 with the necessary physical properties can be arranged depending on the locations of the buffer materials 41, 42. Therefore, deformation of the electrode stack 2 can be efficiently suppressed. Moreover, the physical properties of the first buffer section 43 are similar to those of the electrode stack 2. The physical properties of the second buffer section 44 are similar to those of the negative electrode current collector 16. Therefore, deformation of each part of the electrode stack 2 can be effectively suppressed individually.

[0054] The present invention is not limited to the above-described embodiment, and includes various modifications to the above-described embodiment without departing from the spirit of the present invention.

[0055] For example, in the above-described embodiment, the area of ​​the negative electrode active material layer 15 is larger than the area of ​​the positive electrode active material layer 13. The area of ​​each of the solid electrolyte layers 11, 12 is equal to the area of ​​the negative electrode active material layer 15. However, this is not limited thereto, and the area of ​​the positive electrode active material layer 13, the area of ​​the negative electrode active material layer 15, and the area of ​​each of the solid electrolyte layers 11, 12 can be determined arbitrarily. For example, the area of ​​each of the solid electrolyte layers 11, 12 may be smaller than the area of ​​the positive electrode active material layer 13 or the area of ​​the negative electrode active material layer 15. The area of ​​the positive electrode active material layer 13 may be larger than the area of ​​the negative electrode active material layer 15.

[0056] In the above embodiment, the buffer materials 41, 42 are formed in an L-shape in cross section in the stacking direction of the electrode stack 2, and have a first buffer portion 43 and a second buffer portion 44. However, this is not limited to this, and any shape may be used as long as it fills at least the space between the positive electrode layers 6, 7 and the negative electrode layers 8, 9. The shape of each buffer material 41, 42 can be determined arbitrarily depending on the shape of the electrode stack 2. When the second buffer section 44 is provided, it may have a shape that covers the outermost periphery of the electrode stack 2.

[0057] In the above-described embodiment, the battery is described as having two positive electrode layers 6, 7 and two negative electrode layers 8, 9. However, the present invention is not limited to this, and the number of positive electrode layers and negative electrode layers may be one layer or three or more layers. The solid electrolyte layers 11, 12 may be disposed between the positive electrode layers and the negative electrode layers.

[0058] In the above-described embodiment, the first negative electrode layer 8 is disposed on the opposite side of the first positive electrode layer 6 from the second positive electrode layer 7. The second negative electrode layer 9 is disposed on the opposite side of the second positive electrode layer 7 from the first positive electrode layer 6. However, this is not limiting, and the positions of the positive electrode layers 6, 7 and the negative electrode layers 8, 9 may be reversed.

[0059] In the above embodiment, the load input portion 32 of the battery manufacturing apparatus 30 is described as including a rod body 35 and a flange portion 36 provided at the end of the rod body 35 on the pressing portion 31 side. However, this is not limited to this, and the load input portion 32 may have any structure as long as it can compress the electrode stack 2 in the stacking direction via the pressing portion 31.

[0060] In the above embodiment, the battery manufacturing apparatus 30 has been described as a case in which a pressing force is applied to each load input portion 32 from the control portion main body 37 of the pressurization control portion 33 via the control spring 38. However, this is not limited to this, and the battery manufacturing apparatus 30 may be configured so that the load input portion 32 presses the control spring 38, and the control spring 38 presses the pressing portion 31.

[0061] In the above embodiment, the pressure control unit 33 includes the control unit main body 37 that applies a pressing force to the pressing unit 31 to each load input unit 32, and a plurality of control springs 38 attached to each load input unit 32 from the side opposite the pressing unit 31. However, this is not limited to this. For example, the control unit main body 37 may be provided with a plurality of through holes (not shown) through which the load input units 32 are inserted, and the load input units 32 may be inserted into these through holes. The control springs 38 may be inserted into the rod bodies 35 of the load input units 32. With this configuration, the loads applied to the pressing units 31 by the load input units 32 can be individually controlled by the corresponding control springs 38. [Explanation of symbols]

[0062] 2...Electrode laminate 6...First positive electrode layer (positive electrode layer) 7...Second positive electrode layer (positive electrode layer) 8...First negative electrode layer (negative electrode layer) 9...Second negative electrode layer (negative electrode layer) 11...First solid electrolyte layer (solid electrolyte layer) 12...Second solid electrolyte layer (solid electrolyte layer) 30...Battery manufacturing equipment 31...Pressing part 32...Load input section 33...Pressure control section 34...Cushioning material 41...First buffer material (buffer material) 42...Second buffer material (buffer material) 43...1st buffer section 44…Second buffer section G...gap

Claims

1. A battery manufacturing apparatus that applies pressure to an electrode stack including: a positive electrode layer; an anode layer that is disposed opposite the positive electrode layer in a thickness direction and has an area different from an area of ​​the positive electrode layer; and a solid electrolyte layer that is disposed between the positive electrode layer and the anode layer, a pressing portion that contacts the electrode stack in a state in which the positive electrode layer, the negative electrode layer, and the solid electrolyte layer are stacked together from an outer side in the stacking direction of the electrode stack; a plurality of load input units that apply loads to the pressing units so as to compress the electrode stack in a stacking direction; a buffer material that fills a gap between the positive electrode layer and the negative electrode layer; Equipped with the plurality of load input portions are arranged along a direction perpendicular to the stacking direction of the electrode stack, a pressure control unit that individually controls the loads applied to the pressing unit by the plurality of load input units, A battery manufacturing apparatus characterized by:

2. The buffer material is a first buffer section disposed within a range in which the electrode stack is disposed when viewed from the stacking direction of the electrode stack; a second buffer portion covering the outermost periphery of the electrode stack; Including, 2. The battery manufacturing apparatus according to claim 1.

3. The physical properties of the first buffer portion and the second buffer portion are different from each other.

3. The battery manufacturing apparatus according to claim 2.

4. the physical properties of the first buffer portion are similar to the physical properties of the electrode stack; The physical properties of the second buffer portion are similar to the physical properties of the current collector drawn from the electrode stack.

4. The battery manufacturing apparatus according to claim 3.

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